User's Manual
Target Devices:
78K/IV Series
Printed in Japan
Document No. U15556EJ1V0UM00 (1st edition)
Date Published November 2001 N CP(K)
CC78K4 Ver.2.30 or Later
C Compiler
Language
2001
User's Manual U15556EJ1V0UM
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[MEMO]
User's Manual U15556EJ1V0UM
3
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M8E 00. 4
The information in this document is current as of July, 2001. The information is subject to change
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books, etc., for the most up-to-date specifications of NEC semiconductor products. Not all products
and/or types are available in every country. Please check with an NEC sales representative for
availability and additional information.
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Descriptions of circuits, software and other related information in this document are provided for illustrative
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(Note)
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User's Manual U15556EJ1V0UM
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J01.2
User's Manual U15556EJ1V0UM
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INTRODUCTION
The CC78K4 C Compiler (hereafter referred to as this C compiler) was developed based on CHAPTER 2
ENVIRONMENT and CHAPTER 3 LANGUAGE in the Draft Proposed American National Standard for
Information Systems - Programming Language C (December 7, 1988). Therefore, by compiling C source
programs conforming to the ANSI standard with this C compiler, 78K/IV Series application products can be
developed.
The CC78K4 C Compiler Language (this manual) has been prepared to give those who develop software by
using this C compiler a correct understanding of the basic functions and language specifications of this C compiler.
This manual does not cover how to operate this C compiler. Therefore, after you have comprehended the
contents of this manual, read the CC78K4 C Compiler Operation User's Manual (U15557E).
For the architecture of 78K/IV Series, refer to the user's manual of each product of 78K/IV Series.
User's Manual U15556EJ1V0UM
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[Target Devices]
Software for the 78K/IV Series microcontrollers can be developed with this C compiler.
Note that the device file (sold separately) corresponding to the target device is necessary.
[Target Readers]
Although this manual is intended for those who have read the user's manual of the microcontroller subject to software
development and have experience in software programming, the reader need not necessarily have knowledge of C
compilers or C language. Discussions in this manual assume that readers are familiar with software terminology.
[Organization]
This manual consists of the following 13 chapters and appendixes.
CHAPTER 1 GENERAL
Outlines the general functions of C compilers and the performance characteristics and features of this
C compiler.
CHAPTER 2 CONSTRUCTS OF C LANGUAGE
Explains the constituent elements of a C source module file.
CHAPTER 3 DECLARATION OF TYPES AND STORAGE CLASSES
Explains the data types and storage classes used in C and how to declare the type and storage class
of a data object or function.
CHAPTER 4 TYPE CONVERSIONS
Explains the conversions of data types to be automatically carried out by this C compiler.
CHAPTER 5 OPERATORS AND EXPRESSIONS
Describes the operators and expressions that can be used in C and the priority of operators.
CHAPTER 6 CONTROL STRUCTURES OF C LANGUAGE
Explains the program control structures of C and the statements to be executed in C.
CHAPTER 7 STRUCTURES AND UNIONS
Explains the concept of structures and unions and how to refer to structure and union members.
CHAPTER 8 EXTERNAL DEFINITIONS
Describes the types of external definitions and how to use external declarations.
CHAPTER 9 PREPROCESSING DIRECTIVES
Details the types of preprocessing directives and how to use each preprocessing directive.
CHAPTER 10 LIBRARY FUNCTIONS
Details the types of C library functions and how to use each library function.
CHAPTER 11 EXTENDED FUNCTIONS
Explains the extended functions of this C compiler provided to make the most of the target device.
CHAPTER 12 REFERENCING BETWEEN C AND ASSEMBLER
Describes the method of linking a C source program with a program written in assembly language.
CHAPTER 13 EFFECTIVE UTILIZATION
Outlines how to effectively use this C compiler.
APPENDIXES A through E
Contain a list of labels for saddr area, a list of segment names, a list of runtime libraries, a list of library
stack consumption, and an index for quick reference.
User's Manual U15556EJ1V0UM
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[How to Read This Manual]
For those who are not familiar with C compilers or C language:
Read from CHAPTER 1, as this manual covers from the program control structures of C to the extended functions
of this C compiler. In CHAPTER 1, an example of C source program is used to show where in the manual details
can be referenced.
For those who are familiar with C compilers or C language:
The language specifications of this C compiler conform to ANSI Standard C. Therefore, you may start from
CHAPTER 11, which explains the extended functions unique to this C compiler. When reading CHAPTER 11,
also refer to the user's manual supplied with the target device in the 78K/IV Series, if necessary.
[Related Documents]
Document Name
Document No.
CC78K4 C Compiler Operation User's Manual
U15557E
[Reference]
Draft Proposed American National Standard for Information Systems - Programming Language C (December
7, 1988)
[Terms]
RTOS = 78K/IV Series Real-time OS RX78K/IV
[Conventions]
The following conventions are used in this manual.
Symbol
Meaning
...
Continuation (repetition) of data in the same format
" "
Characters enclosed in a pair of double quotes must be input as is.
` '
Characters enclosed in a pair of single quotes must be input as is.
:
This part of the program description is omitted.
/
Delimiter
\
Backslash
[ ]
Parameters in square brackets may be omitted.
User's Manual U15556EJ1V0UM
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CONTENTS
CHAPTER 1 GENERAL ..................................................................................................................... 19
1.1
C Language and Assembly Language ............................................................................... 19
1.2
Program Development Procedure by C Compiler............................................................. 21
1.3
Basic Structure of C Source Program................................................................................ 23
1.3.1
Program format........................................................................................................................ 23
1.4
Reminders Before Program Development ......................................................................... 26
1.5
Features of This C Compiler ............................................................................................... 28
<1>
callt/_ _callt functions ............................................................................................................... 28
<2>
Register variables ...................................................................................................................... 28
<3>
Using the saddr area................................................................................................................. 29
<4>
sfr area ...................................................................................................................................... 29
<5>
noauto functions ....................................................................................................................... 29
<6>
norec/_ _leaf functions ............................................................................................................. 29
<7>
bit type variables and boolean/_ _boolean type variables ...................................................... 29
<8>
boolean1 type variables ............................................................................................................ 29
<9>
ASM statements......................................................................................................................... 29
<10> Interrupt functions ...................................................................................................................... 29
<11> Interrupt function qualifier .......................................................................................................... 29
<12> Interrupt function ........................................................................................................................ 30
<13> CPU control instructions ............................................................................................................ 30
<14> callf/_ _callf function ................................................................................................................. 30
<15> Usage of 16 MB expansion space ............................................................................................. 30
<16> Location function........................................................................................................................ 30
<17> Absolute address access function ............................................................................................. 30
<18> Bit field declaration .................................................................................................................... 30
<19> Function to change compiler output section name .................................................................... 30
<20> Binary constant description function .......................................................................................... 30
<21> Module name change functions ................................................................................................. 30
<22> Rotate function........................................................................................................................... 30
<23> Multiplication function ................................................................................................................ 30
<24> Division function......................................................................................................................... 30
<25> Data insertion function ............................................................................................................... 31
<26> Interrupt handler for RTOS ........................................................................................................ 31
<27> Interrupt handler qualifier for RTOS........................................................................................... 31
<28> Task function for RTOS ............................................................................................................. 31
<29> Changing function call interface................................................................................................. 31
<30> Change of calculation method of offset of arrays and pointers.................................................. 31
<31> Pascal function (_ _pascal) ....................................................................................................... 31
<32>
Automatic pascal functionization of function call interface......................................................... 31
<33> Flash area allocation method..................................................................................................... 31
<34> Flash area branch table ............................................................................................................. 31
<35> Function call function from boot area to flash area .................................................................... 31
<36> Firmware ROM function ............................................................................................................. 31
<37> Limiting int expansion of argument/return value........................................................................ 32
<38> Memory manipulation function ................................................................................................... 32
User's Manual U15556EJ1V0UM
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<39> callf two-step branch function ................................................................................................... 32
<40>
Automatic callf functionization of function call interface............................................................ 32
<41> Three-byte address reference/generation function.................................................................... 32
<42> Absolute address allocation specification.................................................................................. 32
CHAPTER 2 CONSTRUCTS OF C LANGUAGE............................................................................33
2.1
Character Sets.......................................................................................................................34
(1)
Character sets .............................................................................................................................. 34
(2)
Escape sequences ....................................................................................................................... 35
(3)
Trigraph sequences...................................................................................................................... 35
2.2
Keywords ...............................................................................................................................36
(1)
ANSI keywords ............................................................................................................................. 36
(2)
Keywords added for the CC78K4 ................................................................................................. 36
2.3
Identifiers ...............................................................................................................................37
2.3.1
Scope of identifiers.................................................................................................................. 37
(1)
Function scope ............................................................................................................... 38
(2)
File scope ....................................................................................................................... 38
(3)
Block scope .................................................................................................................... 38
(4)
Function prototype scope ............................................................................................... 38
2.3.2
Linkage of identifiers ............................................................................................................... 39
(1)
External linkage.............................................................................................................. 39
(2)
Internal linkage ............................................................................................................... 39
(3)
No linkage ...................................................................................................................... 39
2.3.3
Name space for identifiers....................................................................................................... 39
2.3.4
Storage duration of objects ..................................................................................................... 39
(1)
Static storage duration ................................................................................................... 39
(2)
Automatic storage duration ............................................................................................ 40
2.3.5
Data types ............................................................................................................................... 40
(1)
Basic types ..................................................................................................................... 41
(2)
Character types .............................................................................................................. 44
(3)
Incomplete types ............................................................................................................ 45
(4)
Derived types ................................................................................................................. 45
(5)
Scalar types.................................................................................................................... 45
2.3.6
Compatible type and composite type ...................................................................................... 46
(1)
Compatible type ............................................................................................................. 46
(2)
Composite type .............................................................................................................. 46
2.4
Constants...............................................................................................................................46
2.4.1
Floating-point constant ............................................................................................................ 47
2.4.2
Integer constant....................................................................................................................... 47
(1)
Decimal constant............................................................................................................ 47
(2)
Octal constant ................................................................................................................ 47
(3)
Hexadecimal constant .................................................................................................... 47
2.4.3
Enumeration constants............................................................................................................ 48
2.4.4
Character constants ................................................................................................................ 48
2.5
String Literals ........................................................................................................................49
2.6
Operators ...............................................................................................................................49
2.7
Delimiters...............................................................................................................................49
2.8
Header Name .........................................................................................................................50
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2.9
Comment............................................................................................................................... 50
CHAPTER 3 DECLARATION OF TYPES AND STORAGE CLASSES....................................... 51
3.1
Storage Class Specifiers ..................................................................................................... 52
(1)
typedef .......................................................................................................................................... 52
(2)
extern............................................................................................................................................ 52
(3)
static ............................................................................................................................................. 52
(4)
auto............................................................................................................................................... 52
(5)
register.......................................................................................................................................... 52
3.2
Type Specifiers ..................................................................................................................... 53
3.2.1
Structure specifier and union specifier .................................................................................... 55
(1)
Structure specifier........................................................................................................... 55
(2)
Union specifier................................................................................................................ 55
(3)
Bit field............................................................................................................................ 56
3.2.2
Enumeration specifiers ............................................................................................................ 56
3.2.3
Tags......................................................................................................................................... 57
3.3
Type Qualifiers ..................................................................................................................... 58
3.4
Declarators............................................................................................................................ 59
3.4.1
Pointer declarators .................................................................................................................. 59
3.4.2
Array declarators ..................................................................................................................... 59
3.4.3
Function declarators (including prototype declarations) .......................................................... 60
3.5
Type Names .......................................................................................................................... 60
3.6
typedef Declarations ............................................................................................................ 60
3.7
Initialization........................................................................................................................... 62
(1)
Initialization of objects which have a static storage duration ........................................................ 62
(2)
Initialization of objects that have an automatic storage duration .................................................. 62
(3)
Initialization of character arrays.................................................................................................... 62
(4)
Initialization of aggregate or union type objects ........................................................................... 63
CHAPTER 4 TYPE CONVERSIONS ................................................................................................ 65
4.1
Arithmetic Operands............................................................................................................ 67
(1)
Characters and integers (general integral promotion) .................................................................. 67
(2)
Signed integers and unsigned integers ........................................................................................ 67
(3)
Usual arithmetic type conversions ................................................................................................ 68
4.2
Other Operands .................................................................................................................... 69
(1)
Left-side values and function locators .......................................................................................... 69
(2)
void ............................................................................................................................................... 69
(3)
Pointers ........................................................................................................................................ 69
CHAPTER 5 OPERATORS AND EXPRESSIONS .......................................................................... 70
5.1
Primary Expressions............................................................................................................ 73
5.2
Postfix Operators ................................................................................................................. 73
(1)
Subscript operators ...................................................................................................................... 74
(2)
Function call operators ................................................................................................................. 75
(3)
Structure and union member ........................................................................................................ 76
(4)
Postfix Increment/Decrement operators ....................................................................................... 78
5.3
Unary Operators ................................................................................................................... 79
(1)
Prefix Increment and Decrement operators.................................................................................. 80
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(2)
Address and Indirection operators ............................................................................................... 81
(3)
Unary Arithmetic operators (+ ~ !) ............................................................................................. 82
(4)
sizeof operators............................................................................................................................ 83
5.4
Cast Operators ......................................................................................................................84
5.5
Arithmetic Operators ............................................................................................................85
(1)
Multiplicative operators................................................................................................................. 86
(2)
Additive operators ........................................................................................................................ 87
5.6
Bitwise Shift Operators ........................................................................................................88
5.7
Relational Operators.............................................................................................................90
(1)
Relational operators ..................................................................................................................... 91
(2)
Equality operators ........................................................................................................................ 92
5.8
Bitwise Logical Operators....................................................................................................93
(1)
Bitwise AND operators ................................................................................................................. 94
(2)
Bitwise XOR operators ................................................................................................................. 95
(3)
Bitwise Inclusive OR operators .................................................................................................... 96
5.9
Logical Operators .................................................................................................................97
(1)
Logical AND operators ................................................................................................................. 98
(2)
Logical OR operators ................................................................................................................... 99
5.10 Conditional Operators ........................................................................................................100
5.11 Assignment Operators .......................................................................................................101
(1)
Simple assignment operators ..................................................................................................... 102
(2)
Compound assignment operators .............................................................................................. 103
5.12 Comma Operator.................................................................................................................104
5.13 Constant Expressions ........................................................................................................105
(1)
General integral constant expression......................................................................................... 105
(2)
Arithmetic constant expression .................................................................................................. 105
(3)
Address constant expression ..................................................................................................... 105
CHAPTER 6 CONTROL STRUCTURES OF C LANGUAGE ......................................................106
6.1
Labeled Statements ............................................................................................................108
(1)
case label ................................................................................................................................... 109
(2)
default label ................................................................................................................................ 111
6.2
Compound Statements or Blocks .....................................................................................112
6.3
Expression Statements and Null Statements...................................................................112
6.4
Conditional Statements ......................................................................................................113
(1)
if and if ... else statements.......................................................................................................... 114
(2)
switch statement......................................................................................................................... 115
6.5
Iteration Statements............................................................................................................116
(1)
while statement .......................................................................................................................... 117
(2)
do statement............................................................................................................................... 118
(3)
for statement .............................................................................................................................. 119
6.6
Branch Statements .............................................................................................................120
(1)
goto statement............................................................................................................................ 121
(2)
continue statement ..................................................................................................................... 122
(3)
break statement.......................................................................................................................... 123
(4)
return statement ......................................................................................................................... 124
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CHAPTER 7 STRUCTURES AND UNIONS .................................................................................... 125
7.1
Structures ........................................................................................................................... 126
(1)
Declaration of structure and structure variable ........................................................................... 126
(2)
Structure declaration list ............................................................................................................. 127
(3)
Arrays and pointers .................................................................................................................... 128
(4)
How to refer to structure members ............................................................................................. 129
7.2
Unions ................................................................................................................................. 130
(1)
Declaration of union and union variable ..................................................................................... 130
(2)
Union declaration list .................................................................................................................. 130
(3)
Union arrays and pointers .......................................................................................................... 131
(4)
How to refer to union members .................................................................................................. 132
CHAPTER 8 EXTERNAL DEFINITIONS ........................................................................................ 133
8.1
Function Definition............................................................................................................. 134
8.2
External Object Definitions ............................................................................................... 136
CHAPTER 9 PREPROCESSING DIRECTIVES (COMPILER DIRECTIVES) .............................. 137
9.1
Conditional Translation Directives ................................................................................... 137
(1)
#if directive ................................................................................................................................. 138
(2)
#elif directive............................................................................................................................... 139
(3)
#ifdef directive ............................................................................................................................ 140
(4)
#ifndef directive .......................................................................................................................... 141
(5)
#else directive............................................................................................................................. 142
(6)
#endif directive ........................................................................................................................... 143
9.2
Source File Inclusion Directive ......................................................................................... 144
(1)
#include < > ............................................................................................................................... 145
(2)
#include " " ................................................................................................................................. 146
(3)
#include preprocessing token string ........................................................................................... 147
9.3
Macro Replacement Directives ......................................................................................... 148
(1)
Actual argument replacement..................................................................................................... 148
(2)
# operator ................................................................................................................................... 148
(3)
## operator ................................................................................................................................. 148
(4)
Re-scanning and further replacement ........................................................................................ 149
(5)
Scope of macro definition ........................................................................................................... 149
(6)
#define directive ......................................................................................................................... 150
(7)
#define( ) directive ..................................................................................................................... 151
(8)
#undef directive .......................................................................................................................... 152
9.4
Line Control Directive ........................................................................................................ 153
(1)
To change the line number ......................................................................................................... 153
(2)
To change the line number and the file name ............................................................................ 153
(3)
To change using preprocessing token string.............................................................................. 153
9.5
#error Preprocessing Directive ......................................................................................... 154
9.6
#pragma Directives ............................................................................................................ 155
9.7
Null Directives .................................................................................................................... 155
9.8
Compiler-Defined Macro Names ....................................................................................... 156
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CHAPTER 10 LIBRARY FUNCTIONS ............................................................................................158
10.1 Interface Between Functions .............................................................................................159
10.1.1
Arguments ............................................................................................................................. 159
10.1.2
Return values ........................................................................................................................ 160
10.1.3
Saving registers to be used by individual libraries ................................................................ 160
(1)
When -ZR option is not specified ................................................................................. 160
(2)
When -ZR option is specified ....................................................................................... 162
10.2 Headers ................................................................................................................................163
(1)
ctype.h........................................................................................................................................ 163
(2)
setjmp.h ...................................................................................................................................... 163
(3)
stdarg.h ...................................................................................................................................... 163
(4)
stdio.h......................................................................................................................................... 164
(5)
stdlib.h ........................................................................................................................................ 164
(6)
string.h........................................................................................................................................ 165
(7)
error.h ......................................................................................................................................... 165
(8)
errno.h ........................................................................................................................................ 165
(9)
limits.h ........................................................................................................................................ 165
(10) stddef.h....................................................................................................................................... 166
(11) math.h ........................................................................................................................................ 166
(12) float.h.......................................................................................................................................... 167
(13) assert.h....................................................................................................................................... 169
10.3 Re-entrantability..................................................................................................................169
(1)
Functions that cannot be re-entranced....................................................................................... 169
(2)
Functions that use the area secured in the startup routine ........................................................ 169
(3)
Functions that deal with floating-point numbers ......................................................................... 169
10.4 Standard Library Functions ...............................................................................................170
10.5 Batch Files for Update of Startup Routine and Library Functions ................................279
10.5.1
Using batch files .................................................................................................................... 280
CHAPTER 11 EXTENDED FUNCTIONS.........................................................................................283
11.1 Macro Names.......................................................................................................................284
11.2 Keywords .............................................................................................................................284
(1)
Functions.................................................................................................................................... 285
(2)
Variables .................................................................................................................................... 286
11.3 Memory ................................................................................................................................287
(1)
Memory model............................................................................................................................ 287
(2)
Register bank ............................................................................................................................. 287
(3)
Location function ........................................................................................................................ 287
(4)
Memory space ............................................................................................................................ 288
11.4 #pragma directives .............................................................................................................289
11.5 How to Use Extended Functions .......................................................................................291
(1)
callt functions.............................................................................................................................. 292
(2)
Register variables....................................................................................................................... 295
(3)
How to use the saddr area ......................................................................................................... 301
(4)
How to use the sfr area .............................................................................................................. 309
(5)
noauto function........................................................................................................................... 312
(6)
norec function............................................................................................................................. 318
(7)
bit type variables ........................................................................................................................ 326
User's Manual U15556EJ1V0UM
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(8)
_ _boolean1 type variables......................................................................................................... 331
(9)
ASM statements ......................................................................................................................... 336
(10) Interrupt functions ....................................................................................................................... 340
(11) Interrupt function qualifier (_ _interrupt, _ _interrupt_brk) .......................................................... 346
(12) Interrupt functions ....................................................................................................................... 349
(13) CPU control instruction ............................................................................................................... 352
(14) callf functions.............................................................................................................................. 356
(15) 16 MB expansion space utilization ............................................................................................. 358
(16) Allocation function ...................................................................................................................... 361
(17) Absolute address access function .............................................................................................. 363
(18) Bit field declaration ..................................................................................................................... 367
(19) Changing compiler output section name .................................................................................... 375
(20) Binary constant ........................................................................................................................... 389
(21) Module name changing function................................................................................................. 391
(22) Rotate function ........................................................................................................................... 392
(23) Multiplication function ................................................................................................................. 395
(24) Division function ......................................................................................................................... 398
(25) Data insertion function ................................................................................................................ 400
(26) Interrupt handler for real-time OS (RTOS).................................................................................. 402
(27) Interrupt handler qualifier for real-time OS (RTOS) .................................................................... 408
(28) Task function for real-time OS (RTOS)....................................................................................... 410
(29) Changing function call interface ................................................................................................. 413
(30) Changing the method of calculating the offset of arrays and pointers........................................ 414
(31) Pascal function ........................................................................................................................... 421
(32) Automatic pascal functionization of the function call interface ................................................... 424
(33) Flash area allocation method ..................................................................................................... 425
(34) Flash area branch table .............................................................................................................. 426
(35) Function call function from the boot area to the flash area......................................................... 430
(36) Firmware ROM function .............................................................................................................. 433
(37) Method of int expansion limitation of argument/return value ...................................................... 434
(38) Memory manipulation function.................................................................................................... 436
(39) callf two-step branch function ..................................................................................................... 441
(40) Automatic callf functionization of function call interface ............................................................. 444
(41) Three-byte address reference/generation function..................................................................... 445
(42) Absolute address allocation specification................................................................................... 448
11.6 Modifications of C Source ................................................................................................. 452
11.7 Function Call Interface....................................................................................................... 453
11.7.1
Return value .......................................................................................................................... 454
11.7.2
Ordinary function call interface .............................................................................................. 455
(1)
Passing arguments ....................................................................................................... 455
(2)
Location and order of storing arguments ...................................................................... 456
(3)
Location and order of storing automatic variables........................................................ 458
11.7.3
noauto function call interface................................................................................................. 460
(1)
Passing arguments ....................................................................................................... 460
(2)
Location and order of storing arguments ...................................................................... 460
(3)
Location and order of storing automatic variables........................................................ 461
11.7.4
norec function call interface................................................................................................... 463
(1)
Passing arguments ....................................................................................................... 463
User's Manual U15556EJ1V0UM
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(2)
Location and order of storing arguments...................................................................... 463
(3)
Location and order of storing automatic variables........................................................ 465
11.7.5
Pascal function call interface................................................................................................. 467
CHAPTER 12 REFERENCING THE ASSEMBLER .......................................................................470
12.1 Accessing Arguments/Automatic Variables ....................................................................471
12.2 Storing Return Values ........................................................................................................474
12.3 Calling an Assembly Language Routine from C..............................................................475
(1)
Calling an assembly language routine function (C source) ........................................................ 475
(2)
Saving and restoring the information of assembly language routine (assembler source) ......... 476
12.4 Calling C Language Routine from Assembly Language Routine ..................................479
(1)
Calling a C language function from assembly language (assembler source)............................. 479
12.5 Referencing Variables Defined by Other Languages ......................................................481
(1)
How to refer to C-defined variables ............................................................................................ 481
(2)
How to refer to assembler-defined variables from C .................................................................. 482
12.6 Other Important Hints .........................................................................................................483
(1)
"_" (underscore).......................................................................................................................... 483
(2)
Placement of arguments on the stack ........................................................................................ 483
CHAPTER 13 EFFECTIVE UTILIZATION OF COMPILER...........................................................484
13.1 Efficient Coding...................................................................................................................484
(1)
Using external variables ............................................................................................................. 485
(2)
1-bit data .................................................................................................................................... 485
(3)
Function definitions .................................................................................................................... 486
(4)
Optimization option..................................................................................................................... 486
(5)
Using extended functions ........................................................................................................... 487
APPENDIX A LIST OF LABELS FOR saddr AREA...................................................................490
A.1
Arguments of norec Functions..........................................................................................490
A.2
Automatic variables of norec Functions ..........................................................................491
A.3
Register Variables...............................................................................................................491
APPENDIX B LIST OF SEGMENT NAMES ..................................................................................492
B.1
List of Segment Names ......................................................................................................494
B.1.1
Program area and data area ................................................................................................. 494
B.1.2
Flash memory area ............................................................................................................... 498
B.2
Location of Segment ..........................................................................................................500
B.3
Example of C Source ..........................................................................................................501
B.4
Example of Output Assembler Module .............................................................................502
APPENDIX C LIST OF RUNTIME LIBRARIES .............................................................................505
APPENDIX D LIST OF LIBRARY STACK CONSUMPTION .......................................................510
APPENDIX E INDEX .........................................................................................................................517
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LIST OF FIGURES
)LJXUH 1R
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3DJH
1-1
Flow of Compilation ................................................................................................................................. 20
1-2
Program Development Procedure by This C Compiler............................................................................ 22
4-1
Usual Arithmetic Type Conversions......................................................................................................... 68
6-1
Control Flows of Conditional Statements............................................................................................... 113
6-2
Control Flows of Iteration Statements.................................................................................................... 116
6-3
Control Flows of Branch Statements ..................................................................................................... 120
10-1
Stack Area When Function Is Called (No ZR Specified) ..................................................................... 161
10-2
Stack Area When Function Is Called (ZR Specified) ........................................................................... 162
10-3
Syntax of Format Commands ................................................................................................................ 181
10-4
Syntax of Input Format Commands ....................................................................................................... 185
11-1
Bit Allocation by Bit Field Declaration (Example 1)................................................................................ 369
11-2
Bit Allocation by Bit Field Declaration (Example 2) ............................................................................... 370
11-3
Bit Allocation by Bit Field Declaration (Example 3) ............................................................................... 372
12-1
Stack Area After Call ............................................................................................................................. 475
12-2
Stack Area After Return......................................................................................................................... 478
12-3
Calling Assembly Language Routine from C ......................................................................................... 478
12-4
Placing Arguments of Stack................................................................................................................... 480
12-5
Placement of Arguments on Stack ........................................................................................................ 483
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LIST OF TABLES (1/2)
7DEOH 1R
7LWOH
3DJH
1-1
Maximum Performance Characteristics of This C Compiler .................................................................... 26
2-1
List of Escape Sequences ....................................................................................................................... 35
2-2
List of Trigraph Sequence ....................................................................................................................... 35
2-3
List of Basic Data Types.......................................................................................................................... 42
2-4
Exponent Relationships........................................................................................................................... 43
2-5
List of Operation Exceptions ................................................................................................................... 44
4-1
List of Conversions Between Types ........................................................................................................ 66
4-2
Conversions from Signed Integral Type to Unsigned Integral Type ........................................................ 67
5-1
Evaluation Precedence of Operators....................................................................................................... 72
5-2
Signs of Division/Remainder Division Operation Result.......................................................................... 85
5-3
Shift Operations....................................................................................................................................... 88
5-4
Bitwise AND Operation............................................................................................................................ 94
5-5
Bitwise XOR Operation............................................................................................................................ 95
5-6
Bitwise OR Operation .............................................................................................................................. 96
5-7
Logical AND Operation............................................................................................................................ 98
5-8
Logical OR Operation .............................................................................................................................. 99
10-1
List of Passing First Argument............................................................................................................... 159
10-2
List of Storing Return Value................................................................................................................... 160
10-3
Batch Files for Updating Library Functions ........................................................................................... 279
11-1
List of Added Keywords......................................................................................................................... 285
11-2
Memory Model....................................................................................................................................... 287
11-3
Utilization of Memory Space.................................................................................................................. 288
11-4
List of #pragma Directives ..................................................................................................................... 290
11-5
Number of callt Attribute Functions That Can Be Used When
-QL Option Is Specified........................ 293
11-6
Restriction on callt Function Usage ....................................................................................................... 293
11-7
Registers to Allocate Register Variables ............................................................................................... 296
11-8
Restrictions on Register Variables Usage ............................................................................................. 297
11-9
Restrictions on sreg Variable Usage ..................................................................................................... 302
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LIST OF TABLES (2/2)
7DEOH 1R
7LWOH
3DJH
11-10
Variables Allocated to saddr2 Area by -RD Option................................................................................ 304
11-11
Variables Allocated to saddr2 Area by -RS Option................................................................................ 305
11-12
Restrictions on sreg1 Variable Usage ................................................................................................... 307
11-13
Registers Used for noauto Function Arguments (With -ZO) .................................................................. 312
11-14
Registers Used for noauto Function Arguments (Without -ZO) ............................................................. 313
11-15
Restrictions on noauto Function Arguments (With -ZO) ........................................................................ 315
11-16
Restrictions on noauto Function Arguments and Automatic Variables (Without -ZO) ........................... 315
11-17
Registers Used for norec Function Arguments: Passing Side (Without -ZO) ........................................ 319
11-18
Registers Used for norec Function Arguments: Receiving Side (Without -ZO) ..................................... 320
11-19
Restrictions on norec Function Arguments (When -ZO Is Specified) .................................................... 321
11-20
Restrictions on norec Function Arguments (When -ZO Is Not Specified).............................................. 322
11-21
Restrictions on norec Function Automatic Variables (When -ZO Is Not Specified) ............................... 323
11-22
Operators That Use Only Constants 0 or 1 (When Using Bit Type Variable) ........................................ 327
11-23
Number of Usable bit Type Variables .................................................................................................... 328
11-24
Operators That Use Only Constants 0 or 1 (When Using Bit Type Variables) ...................................... 332
11-25
Number of Usable _ _boolean1 Type Variables .................................................................................... 333
11-26
Save/Restore Area When Interrupt Function Is Used............................................................................ 341
11-27
Storage Location of Return Values........................................................................................................ 454
11-28
Location Where First Argument Is Passed (On Function Call Side) ...................................................... 455
11-29
List of Storing Arguments (On Function Definition Side, When -ZO Is Not Specified)........................... 456
11-30
List of Storing Arguments (On Function Definition Side, When -ZO Is Specified) ................................. 457
11-31
List of Registers Passing/Receiving norec Arguments (When -ZO Is Not Specified) ............................ 464
12-1
Passing Arguments (Function Call Side) ............................................................................................... 471
12-2
List of Storing Arguments/Automatic Variables (Inside Called Function) .............................................. 472
12-3
Storage Location of Return Values........................................................................................................ 474
C-1
List of Runtime Libraries ....................................................................................................................... 505
D-1
List of Standard Library Stack Consumption ........................................................................................ 510
D-2
List of Runtime Library Stack Consumption .......................................................................................... 514
User's Manual U15556EJ1V0UM
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CHAPTER 1 GENERAL
The CC78K4 C Compiler is a language processing program that converts a source program written in the C
language for the 78K/IV Series or ANSI-C into machine language. By the CC78K4 C compiler, object files or
assembler source files for the 78K/IV Series can be obtained.
1.1 C Language and Assembly Language
To have a microcontroller do its job, programs and data are necessary. These programs and data must be written
by a human being (programmer) and stored in the memory section of the microcontroller. Programs and data that
can be handled by the microcontroller are nothing but a set or combination of binary numbers that is called machine
language.
An assembly language is a symbolic language characterized by one-to-one correspondence of its symbolic
(mnemonic) statements with machine language instructions. Because of this one-to-one correspondence, the
assembly language can provide the computer with detailed instructions (for example, to improve I/O processing
speed). However, this means that the programmer must instruct each and every operation of the computer. For this
reason, it is difficult for him or her to understand the logic structure of the program at a glance, increasing the
likelihood of to make errors in coding.
High-level languages were developed as substitutes for such assembly languages. The high-level languages
include a language called C that allows the programmer to write a program without regard to the architecture of the
computer.
Compared with assembly language programs, it can be said that programs written in C have an easy-to-
understand logic structure.
C has a rich set of parts called functions for use in creating programs. In other words, the programmer can write a
program by combining these functions.
CHAPTER 1 GENERAL
User's Manual U15556EJ1V0UM
20
C is characterized by its ease of understanding by human beings. However, understanding of languages by the
microcontroller cannot be extended up to a program written in C. Therefore, to have the computer understand the C
language program, another program is required to translate C language statements into the corresponding machine
language instructions. A program that translates the C language into machine language is called a C compiler.
This C compiler accepts C source modules as inputs and generates object modules or assembler source modules
as outputs. Therefore, the programmer can write a program in C and if he or she wishes to instruct the computer up
to details of program execution, the C source program can be modified in assembly language. The flow of translation
by this C compiler is illustrated in Figure 1-1.
Figure 1-1. Flow of Compilation
Program written
in C language
(C source module file)
Translation program
(Compiler)
Program coded in a set
of binary numbers
(Object module file)
Translation program
(Assembler)
Program coded in a set
of binary numbers
(Object module file)
(Assembler source
module file)
CHAPTER 1 GENERAL
User's Manual U15556EJ1V0UM
21
1.2 Program Development Procedure by C Compiler
Product (program) development by the C compiler requires a linker, which unites together object module files
created by the compiler, a librarian, which creates library files, and a debugger, which locates and corrects bugs
(errors or mistakes) in each created C source program.
The software required in connection with this C compiler is shown below.
Editor .......................................... for source module file creation
RA78K4 assembler package
Assembler .................................. for converting assembly language into machine language
Object converter ......................... for conversion to HEX-format object module files
Linker.......................................... for linking object module files
Librarian ..................................... for creating library files
Debugger (for 78K/IV) ................ for debugging C source module files
The product development procedure by the C compiler is as shown below.
<1> Divides the product into functions.
<2> Creates a C source module for each function.
<3> Translates each C source module.
<4> Registers the modules to be used frequently in the library.
<5> Links object module files.
<6> Debugs each module.
<7> Converts object modules into HEX-format object files.
As mentioned earlier, this C compiler translates (compiles) a C source module file and creates an object module
file or assembler source module file. By manually optimizing the created assembler source module file and
embedding it into the C source, efficient object modules can be created. This is useful when high-speed processing
is a must or when modules must be made compact.
CHAPTER 1 GENERAL
User's Manual U15556EJ1V0UM
22
Figure 1-2. Program Development Procedure by This C Compiler
Librarian
Assembler
Structured assembler
C compiler
Real-time OS
Linker
List converter
Object converter
Structured
assembler source
C source
Include file
Assembler
source
Assemble list
Object module file
Library file
Load module file
Dedicated parallel
interface/RS-232-C
RS-232-C
HEX-format
object
Absolute
assemble list
PROM programmer
Integrated debugger
System
simulator
In-circuit emulator
Assembler
source
Library
file
CHAPTER 1 GENERAL
User's Manual U15556EJ1V0UM
23
1.3 Basic Structure of C Source Program
1.3.1 Program format
A C language program is a collection of functions. These functions must be created so that they have
independent special-purpose or characteristic actions. All C language programs must have a function main ( ) which
becomes the main routine in C and is the first function that is called when execution begins.
Each function consists of a header part, which defines its function name and arguments, and a body part, which
consists of declarations and statements. The format of C programs is shown below.
Definition of variables/constants
Definition of each data, variable, and macro instruction
main (arguments)
Header of function main ( )
{
statement1;
statement2;
function1 (arguments);
Body of function main ( )
function2 (arguments);
}
function1 (arguments)
{
statement1;
Function 1
statement2;
}
function2 (arguments)
{
statement1;
Function 2
statement2;
}
CHAPTER 1 GENERAL
User's Manual U15556EJ1V0UM
24
An actual C source program looks like this.
#define TRUE 1
#define FALSE 0
#define xxx xxx ........................ <6> Preprocessing (macrodefinition)
#define SIZE 200
void printf (char *, int);
xxx xxxx (xxx, xxx) ...................<7> Function prototype declarator
void putchar (char);
char mark[SIZE+1];
char xxx
.....<1> Type declarator, <5> External definition
main ( )
xx [xx]
..................................................... <2> Operator
{
int i,prime, k, count;
int xxx .......................................... <1> Type declarator
count = 0;
xx = xx ..................................................... <2> Operator
for (i = 0; i <= SIZE;i++)
for (xx;xx;xx) xxx ; ..................<3> Control structure
mark[i] = TRUE;
for (i = 0; i <= SIZE ; i++) {
if (mark[i]) {
prime = i + i + 3;
xxx = xxx + xxx + xxx ................<2> Operator
printf ("%6d", prime);
xxx (xxx);...................................<2> Operator
count++;
if ((count%8) = = 0) putchar ('\n');
.......................
if {xxx) xxx ; ............................ <3> Control structure
for (k = i + prime ; k <= SIZE ; k += prime)
mark [k] = FALSE;
}
}
printf ("\n%d primes found. ", count);
xxx (xxx) ; ..... <2> Operator
}
void printf (char *s, int i)
{
int j;
char *ss;
j = i;
ss = s;
}
void putchar (char c)
char d;
d = c;
}
CHAPTER 1 GENERAL
User's Manual U15556EJ1V0UM
25
<1> Declaration of type and storage class
The data type and storage class of an identifier that indicates a data object are declared. For details, see
CHAPTER 3 DECLARATION OF TYPES AND STORAGE CLASSES.
<2> Operator and expression
These are the statements that instruct the compiler to perform an arithmetic operation, logical operation,
assignment, etc. For details, see CHAPTER 5 OPERATORS AND EXPRESSIONS.
<3> Control structure
This is a statement that specifies the program flow. C has several instructions for each of the control
structures such as Conditional control, Iteration, and Branch. For details, see CHAPTER 6 CONTROL
STRUCTURES OF C LANGUAGE.
<4> Structure or union
A structure or union is declared. A structure is a data object that contains several subobjects or members
that may have different types. A union is defined when two or more variables share the same memory. For
details, see CHAPTER 7 STRUCTURES AND UNIONS.
<5> External definition
A function or external object is declared. A function is one element when a C language program is divided
by a special-purpose or characteristic action. A C program is a collection of these functions. For details,
see CHAPTER 8 EXTERNAL DEFINITIONS.
<6> Preprocessing
This is an instruction for the compiler. #define instructs the compiler to replace a parameter that is the same
as the first operand with the second operand if the parameter appears in the program. For details, see
CHAPTER 9 PREPROCESSINGS (COMPILER DIRECTIVES).
<7> Declaration of function prototype
The return value and argument type of a function are declared.
CHAPTER 1 GENERAL
User's Manual U15556EJ1V0UM
26
1.4 Reminders Before Program Development
Before commencing program development, keep in mind the points (limit values or minimum guaranteed values)
summarized in Table 1-1 below.
Table 1-1. Maximum Performance Characteristics of This C Compiler
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User's Manual U15556EJ1V0UM
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Notes
1. This value applies when symbols can be processed with the available memory space alone without using
any temporary file. When a temporary file is used because of insufficient memory space, this value must
be changed according to the file size.
2. This value includes the reserved macro definitions of the C compiler.
3. The large model provides 1,024 KB of code segments and 16 MB of data and stack segments altogether
(when the ML option is specified). The medium model provides 1,024 KB of code segments and 64 KB
of data and stack segments altogether (when the MM option is specified). The location
(CS0 or CS15) can be specified for both models (the default is large model, location 0FH).
CHAPTER 1 GENERAL
User's Manual U15556EJ1V0UM
28
1.5 Features of This C Compiler
This C compiler has extended functions for CPU code generation that are not supported by ANSI (American
National Standards Institute) Standard C. The extended functions of the C compiler allow the special function
registers for the 78K/IV Series to be described at the C language level and thus help shorten object code and
improve program execution speed. For details of these extended functions, see CHAPTER 11 EXTENDED
FUNCTIONS in this manual.
Outlined here are the following extended functions that help shorten object code and improve execution speed.
callt /_ _callt functions ..................
Functions can be called using the callt table area.
Register variables ..........................
Variables can be allocated to registers.
sreg/_ _sreg/_ _sreg1 variablesVariables can be allocated to the saddr area.
sfr area ..........................................
sfr names can be used.
noauto functions ............................
Functions that do not output code for stack frame formation can be
norec/_ _leaf functions ..................
created.
ASM statements .............................
An assembly language program can be described in a C source
program.
bit type variables,...........................
Accessing the saddr or sfr area can be made on a bit-by-bit basis.
boolean/_ _boolean type variables,
_ _boolean1 type variables
callf/_ _callf functions ...................
A function body can be stored in the callf area.
Bit field declaration ........................
A bit field can be specified with unsigned char type.
Multiplication function.....................
The code to multiply can be directly output with inline expansion.
Division function .............................
The code to divide can be directly output with inline expansion.
Rotate function ...............................
The code to rotate can be directly output with inline expansion.
Absolute address function..............
Specific addresses in the memory space can be accessed.
Data insertion function ...................
Specific data and instructions can be directly embedded in the code
area.
_ _pascal function ..........................
The used stack is corrected on the called function side.
Memory manipulation function ......
memcopy and memset can be directly output with inline expansion.
callf two-step branch function .......
A two-step branch function is performed in the callf area.
Three-byte address
reference/generation function .......
Three-byte address reference/generation is performed.
An outline of the extended functions of this compiler is shown below. For details of each extended function, refer
to CHAPTER 11.
<1> callt/_ _callt functions
Functions can be called by using the callt table area. The address of each function to be called (this
function is called a callt function) is stored in the callt table from which it can be called later. This makes
code shorter than the ordinary call instruction and helps shorten object code.
<2> Register variables
Variables declared with the register storage class specifier are allocated to the register or saddr area.
Instructions to the variables allocated to a register or saddr area are shorter in code length than those to
memory. This helps shorten object and improves program execution speed as well.
CHAPTER 1 GENERAL
User's Manual U15556EJ1V0UM
29
<3> Using the saddr area
Variables declared with the keyword sreg can be allocated to the saddr area. Instructions to these sreg
variables are shorter in code length than those to memory. This helps shorten object code and also
improves program execution speed. Variables can be allocated to the saddr area also by option (only to the
saddr2 area).
<4> sfr area
By declaring use of sfr names, manipulations on the sfr area can be described at the C source file.
<5> noauto functions
Functions declared as noauto do not output code for preprocessing and postprocessing (stack frame
formation). By calling a noauto function, arguments are passed via registers. This helps shorten object
code and improve program execution speed as well. This function has restrictions on arguments/automatic
variables. For the details, refer to 11.5 (5) noauto function.
<6> norec/_ _leaf functions
Functions declared as norec/_ _leaf do not output code for preprocessing and postprocessing (stack frame
formation). By calling a norec/_ _leaf function, arguments are passed via registers as much as possible.
Automatic variables to be used inside a norec/_ _leaf function are allocated to register or the saddr area.
This helps shorten object code and also improve program execution speed. This function has restrictions on
arguments/automatic variables and is not allowed to call a function. For the details, refer to 11.5 (6) norec
function.
<7> bit type variables and boolean/_ _boolean type variables
Variables with a 1-bit storage area are generated. By using the bit type variable or boolean/_ _ boolean
type variable, the saddr2 area can be accessed in bit units.
The boolean/_ _boolean type variable is the same as the bit type variable in terms of both function and
usage.
<8> boolean1 type variables
Variables with a 1-bit storage area are generated. By using the _ _ boolean1 type variable, the saddr1 area
can be accessed in bit units.
The _ _boolean1 type variable is the same as the bit type variable in terms of both function and usage.
<9> ASM statements
The assembler source program described by the user can be embedded in an assembler source file to be
output by this C compiler.
<10> Interrupt functions
A vector table and an object code corresponding to the interrupt are output. This allows programming of
interrupt functions at the C source level.
<11> Interrupt function qualifier
This qualifier allows the setting of a vector table and interrupt function definitions to be described in a
separate file.
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<12> Interrupt function
An interrupt disable instruction and an interrupt enable instruction are embedded in an object.
<13> CPU control instructions
Each of the following instructions is embedded in an object.
Instruction to set the value for halt to the STBC register
Instruction to set the value for stop to the STBC register
brk instruction
nop instruction
<14> callf/_ _callf function
The callf instruction stores the body of a function in the callf entry area and allows the calling of the function
with a code shorter than that with the call instruction. This improves executing speed and shortens the
object code.
<15> Usage of 16 MB expansion space
Object files that linearly access the 16 MB expansion space are generated by an option.
<16> Location function
The location of the saddr area can be changed by an option if the memory model is large or medium.
<17> Absolute address access function
Codes that access the ordinary memory space are created with direct inline expansion without resort to a
function call, and an object file is created.
<18> Bit field declaration
By specifying a bit field to be unsigned char type, the memory can be saved, object code can be shortened,
and execution speed can be improved.
<19> Function to change compiler output section name
By changing the compiler section output name, the section can be independently allocated with a linker.
<20> Binary constant description function
Binary can be described in the C source.
<21> Module name change functions
Object module names can be freely changed in the C source.
<22> Rotate function
The code to rotate the value of an expression to the object can be directly output with inline expansion.
<23> Multiplication function
The code to multiply the value of an expression to the object can be directly output with inline expansion.
This function can shorten the object code and improve the execution speed.
<24> Division function
The code to divide the value of an expression to the object can be directly output with inline expansion. This
function can shorten the object code and improve the execution speed.
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<25> Data insertion function
Constant data is inserted in the current address. Specific data and instructions can be embedded in the
code area without using assembler description.
<26> Interrupt handler for RTOS
Interrupt handlers for the RX78K/IV (real-time OS) can be described. Vectors can be set (settings of
interrupt request name, function name for handlers, and stack switching) by the #pragma directive.
<27> Interrupt handler qualifier for RTOS
This qualifier allows the interrupt handler description and the vector setting for the RX78K/IV (real-time OS)
to be made in separate files.
<28> Task function for RTOS
Specified functions are interpreted as the tasks for the RX78K/IV (real-time OS) by the #pragma directive.
This allows the description of task function for RTOS with better code-efficiency at the C source level.
<29> Changing function call interface
Arguments can be passed by the previous function interface specification (using the stack only, with
CC78K4 Ver.1.00 compatibles) by specifying the -ZO option during compilation.
<30> Change of calculation method of offset of arrays and pointers
The code efficiency is improved by performing an unsigned index calculation for the offset of the arrays and
pointers (distance from the start of the array or pointer).
<31> Pascal function (_ _pascal)
The stack correction used to place arguments during the function call is performed on the called function
side, not on the side calling the function. This shortens the object code when there are function calls in
many places.
<32>
Automatic pascal functionization of function call interface
_ _pascal attributes are added to all functions that can be pascal functionized.
<33> Flash area allocation method
Object files to be allocated to the flash area are generated.
<34> Flash area branch table
Startup routines and interrupt functions can be allocated to the flash area.
A function can be called from the boot area to the flash area.
<35> Function call function from boot area to flash area
A function in the flash area can be called from the boot area.
<36> Firmware ROM function
Manipulations regarding the firmware ROM function can be described at the C source level.
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<37> Limiting int expansion of argument/return value
When the argument/return value of a function has the char/unsigned type, object files that do not perform
int expansion are generated. This method can shorten the object code and improve the execution speed.
<38> Memory manipulation function
Memory manipulation functions can be output to an object directly with inline expansion. This function can
shorten the object code and improve the execution speed.
<39> callf two-step branch function
Compared when a function body is allocated in the callf area, the callf/_ _callf attribute can be added to
many more functions. Therefore, this function can shorten the object code if many functions that include call
function are frequently used.
<40>
Automatic callf functionization of function call interface
The _ _callf attribute is added to all functions except for the callt/_ _callt
_ _interrupt/_ _interrupt_brk/_
_rtos_interrupt functions.
<41> Three-byte address reference/generation function
Three-byte address reference/generation can be performed with a short code without using a complex cast
description.
<42> Absolute address allocation specification
The external variable that declared _ _directmap and a static variable in a function can be allocated to any
address, and multiple variables can be allocated in duplicate to the same address.
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CHAPTER 2 CONSTRUCTS OF C LANGUAGE
This chapter explains the constituent elements of a C source module file.
A C source module file consists of the following tokens (distinguishable units in a sequence of characters).
Keywords
Identifiers
Constants
String literal
Operators
Delimiters
Header name
No. of preprocesses
Comment
The tokens used in a C program description example are shown below.
#include "expand. h"
extern void testb (void);
extern ...........................................................
Keyword
extern void chgb (void);
extern bit data1;
extern bit data2;
data1, data2 .................................................
Identifiers
void main ( )
void...............................................................
Keyword
{
data1 = 1 ;
1 ...................................................................
Constant
data2 = 0 ;
0 ...................................................................
Constant
while(data1) {
while .............................................................
Keyword
data1 = data2 ;
{ } .................................................................
Delimiter
testb( ) ;
= ...................................................................
Operator
}
if (data1 && data2) {
if....................................................................
Keyword
chgb ( ) ;
&&.................................................................
Operator
}
( ) .................................................................
Operator
}
void lprintf (char *s, int I)
lprintf.............................................................
Identifier
{
char, int.........................................................
Keywords
int j;
s, i.................................................................
Identifiers
char *ss;
* ....................................................................
Operator
j = i;
ss = s;
}
.
.
.
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2.1 Character Sets
(1) Character sets
Character sets to be used in C programs include a source character set to be used to describe a source file and
an execution character set to be interpreted in the execution environment.
The value of each character in the execution character set is represented by JIS code.
The following characters can be used in the source character set and execution character set.
26 uppercase letters
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z
26 lowercase letters
a
b
c
d
e
f
g
h
i
j
k
l
m
n
o
p
q
r
s
t
u
v
w
x
y
z
10 decimal numbers
0
1
2
3
4
5
6
7
8
9
29 graphic characters
!
"
#
%
&
`
(
)
*
+
,
-
.
/
:
;
<
=
>
?
[
]
^
--
{
|
}
~
and nonprintable control characters which indicate space, horizontal tab, vertical tab, form feed, etc.
Remark
In character constants, string literals, and comment statements, characters other than the above may
also be used.
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(2) Escape sequences
Nongraphic characters used for control characters such as alert, form feed are represented by escape
sequences. Each escape sequence consists of a backslash (\) and a letter.
Nongraphic characters represented by escape sequences are shown below.
Table 2-1. List of Escape Sequences
Escape Sequence
Meaning
Character Code
\a
Alert
07H
\b
Backspace
08H
\f
Form feed
0CH
\n
Line feed
0AH
\r
Carriage return
0DH
\t
Horizontal tab
09H
\v
Vertical tab
0BH
(3) Trigraph sequences
When a source file includes a list of the three characters (called "trigraph sequence") shown in the left column of
the table below, the list of the three characters is converted into the corresponding single character shown in the
right column.
Table 2-2. List of Trigraph Sequence
Trigraph Sequence
Meaning
??=
#
??(
[
??/
\
??)
]
??'
^
??<
{
??!
|
??>
}
??-
~
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2.2 Keywords
(1) ANSI keywords
The following tokens are used by the C compiler as keywords and thus cannot be used as labels or variable
names.
auto
break
case
char const
continue
default
do
double
else
enum
extern
for
float
goto
if
int
long
register
return
short
signed
sizeof
static
struct
switch
typedef
union
unsigned
void
volatile
while
(2) Keywords added for the CC78K4
In this C compiler the following tokens have been added as keywords to implement its expanded functions. As
with ANSI keywords, hese tokens cannot be used as labels or variable names (when an uppercase character is
included, the token is not regarded as a keyword).
Keywords that do not start with "_ _" can be made invalid by specifying the option that enables only ANSI-C
language specification (ZA).
_ _callt/callt
.................................
Declaration of callt function
_ _callf/callf
.................................
Declaration of callf function
_ _sreg/sreg
......................................
Declaration of sreg variable
_ _sreg1
..............................................
Declaration of sreg1 variable
noauto
...................................................
Declaration of noauto function
_ _leaf/norec
....................................
Declaration of norec function
bit
.........................................................
Declaration of bit type variable
_ _boolean/boolean
.........................
Declaration of boolean type variable
_ _boolean1
........................................
Declaration of boolean1 type variable
_ _interrupt
......................................
Hardware interrupt function
_ _interrupt_brk
.............................
Software interrupt function
_ _asm
...................................................
asm statement
_ _rtos_interrupt
...........................
Interrupt handler for RTOS
_ _pascal
............................................
Pascal function
_ _flash
..............................................
Firmware ROM function
_ _directmap
......................................
Absolute address allocation specification
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2.3 Identifiers
An identifier is the name given to the following variables.
Function
Object
Tag of structure, union, or enumeration type
Member of structure, union, or enumeration type
typedef name
Label name
Macro name
Macro parameter
Each identifier can consist of uppercase letters, lowercase letters, or numeric characters including underscores.
The following characters can be used as identifiers.
There is no restriction on the maximum length of the identifier. In this compiler, however, only the first 249
characters can be identified (refer to Table 1-1 Maximum Performance Characteristics of This C Compiler).
_
(underscore)
a b c d e f g h i j k l m
n o p q r s t u v w x y z
A B C D E F G H I J K L M
N O P Q R S T U V W X Y Z
0 1 2 3 4 5 6 7 8 9
All identifiers must begin with other than a numerical character (namely, a letter or an underscore) and must not
be the same as any keyword.
2.3.1 Scope of identifiers
The range of an identifier within which its use becomes effective is determined by the location at which the
identifier is declared. The scope of identifiers is divided into the following four types.
Function scope
File scope
Block scope
Function prototype scope
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extern _ _ boolean data1, data2;
data1, data2.......................................................... File scope
void testb(int x);
x ...................................................... Function prtotype scope
void main(void)
{
int cot ;
cot ...................................................................... Block scope
data1 = 1 ;
data2 = 0 ;
while(data1) {
data1 = data2;
j1 :
j1 ................................................................... Function scope
testb (cot) ;
}
}
void testb(int x)
x ......................................................................... Block scope
{
.
.
.
(1) Function scope
Function scope refers to the entirety within a function. An identifier with function scope can be referenced from
anywhere within a specified function.
Identifiers that have function scope are label names only.
(2) File scope
File scope refers to the entirety of a translation (compiling) unit. Identifiers that are declared outside a block or
parameter list all have file scope. An identifier that has file scope can be referenced from anywhere within the
program.
(3) Block scope
Block scope refers to the range of a block (a sequence of declarations and statements enclosed by a pair of
curly braces { } which begins with the opening brace and ends with the closing brace).
Identifiers that are declared inside a block or parameter list all have block scope. An identifier that has block
scope is effective until the innermost brace pair including the declaration of the identifier is closed.
(4) Function prototype scope
Function prototype scope refers to the range of a declared function from beginning to end. Identifiers that are
declared inside a parameter list within a function prototype all have function prototype scope. An identifier that
has function prototype scope is effective within a specified function.
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2.3.2 Linkage of identifiers
The linkage of an identifier refers to the case when the same identifier declared more than once in different
scopes or in the same scope can be referenced as the same object or function. By being linked an identifier is
regarded to be one and the same. An identifier may be linked in the following three different ways: External linkage,
Internal linkage and No linkage.
(1) External linkage
External linkage refers to identifiers to be linked in translation (compiling) units that constitute the entire program
and as a collection of libraries.
The following identifiers are examples of external linkage.
The identifier of a function declared without a storage class specification.
The identifier of an object or function declared as extern, which has no storage class specification
The identifier of an object which has file scope but has no storage class specification
(2) Internal linkage
Internal linkage refers to identifiers to be linked within one translation (compiling) unit.
The following identifier is an example of internal linkage.
The identifier of an object or function that has file scope and contains the storage class specifier static.
(3) No linkage
An identifier that has no linkage to any other identifier is an inherent entity.
Examples of identifiers that have no linkage are as follows.
An identifier that does not refer to a data object or function
An identifier declared as a function parameter
The identifier of an object that does not have the storage class specifier extern inside a block
2.3.3 Name space for identifiers
All identifiers are classified into the following "name spaces".
Label name...................................................... Distinguished by a label declaration.
Tag name of structure, union, or enumeration
Distinguished by the keyword struct, union or enum
Member name of structure or union ................ Distinguished by the dot (.) operator or arrow (
) operator.
Ordinary identifiers (other than above)............ Declared as ordinary declarators or enumeration type constants.
2.3.4 Storage duration of objects
Each object has a storage duration that determines its lifetime (how long it can remain in memory). This storage
duration is divided into the following two categories: Static storage duration and Automatic storage duration.
(1) Static storage duration
Before executing an object program that has a static duration, an area is reserved for objects and values to be
stored are initialized once. The objects exist throughout the execution of the entire program and retain the
values last stored.
Objects that have a static storage duration are as shown below.
Objects that have external linkage
Objects that have internal linkage
Objects declared by the storage class specifier static
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(2) Automatic storage duration
For objects that have automatic storage duration, an area is reserved when they enter a block to be declared.
If initialization is specified, the objects are initialized as they enter from the beginning of the block. In this case, if
any object enters the block by jumping to a label within the block, the object will not be initialized.
For objects that have automatic storage duration, the reserved area will not be guaranteed after the execution of
the declared block.
Objects that have automatic storage duration are as follows.
Objects that have no linkage
Objects declared inside a block without the storage class specifier static
2.3.5 Data types
A type determines the meaning of the value to be stored in each object.
Data types are divided into the following three categories depending on the variable to be declared.
Object type ................................................... Type that indicates an object with size information
Function type ................................................ Type that indicates a function
Incomplete type ............................................ Type that indicates an object without size information
Basic types
Integral types
char type
(Arithmetic types)
Signed
signed char
integral
short int
types
int
long int
Unsigned integral types
(specified by unsigned)
Enumeration type
Floating point types
float
double
long double
Character types
char
signed char
unsigned char
Incomplete types
Array with an indefinite object size, structure, union,
and void type
Derived types
Array type
Structure type
Union type
Function type
Pointer type
Scalar types
Basic (Arithmetic types)
Pointer type
Aggregate type
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(1) Basic types
A collection of basic data types is also referred to as "arithmetic types". The arithmetic types consist of integral
types and floating-point types.
(a) Integral types
Integral data types are subdivided into four types. Each of these types has a value represented by the
binary numbers 0 and 1.
char type
Signed integral type
Unsigned integral type
Enumeration type
(i)
char type
The char the type has a sufficient size to store any character in the basic execution character set.
The value of the character to be stored in a char type object becomes positive. Data other than
characters is handled as an unsigned integer. In this case, however, if an overflow occurs, the
overflowed part will be ignored.
(ii) Signed integral type
The signed integral type is subdivided into the following four types.
signed char
short int
int
long int
An object declared with the signed char type has an area of the same size as the char type without
a qualifier.
An int object without a qualifier has a size natural to the CPU architecture of the execution
environment. A signed integral type data has its corresponding unsigned integral type data. Both
share an area of the same size. The positive number of a signed integral type data is a partial
collection of unsigned integral type data.
(iii) Unsigned integral data
The unsigned integral type is a data defined with the unsigned keyword. No overflow occurs in any
computation involving unsigned integral type data. This is because if the result of a computation
involving unsigned integral type data becomes a value which cannot be represented by an integral
type, the value will be divided by the maximum number which can be represented by an unsigned
integral type plus 1 and substituted with the remainder in the result of the division.
(iv) Enumeration type
Enumeration is a collection or list of named integer constants. An enumeration type consists of one
or more sets of enumeration.
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(b) Floating-point types
The floating-point types are subdivided into three types.
float
double
long double
In this compiler, double and long double types as well as the float type are supported as a floating-point
expression for the single precision normalized number that is specified in ANSI/IEEE 754-1985. Thus, float,
double, and long double types have the same value range.
Table 2-3. List of Basic Data Types
Type
Value Range
(signed) char
128 to +127
unsigned char
0 to 255
(signed) short int
32768 to +32767
unsigned short int
0 to 65535
(signed) int
32768 to +32767
unsigned int
0 to 65535
(signed) long int
2147483648 to +2147483647
unsigned long int
0 to 4294967295
float
1.17549435E38F to 3.40282347E+38F
double
1.17549435E38F to 3.40282347E+38F
long double
1.17549435E38F to 3.40282347E+38F
The signed keyword may be omitted. However, with the char type, it is judged as signed char or
unsigned char depending on the condition at compilation.
short int data and int data are handled as data that have the same value range but are of
different types.
unsigned short int data and unsigned int data are handled as data that have the same value
range but are of different types.
float, double, and long double data are handled as data that have the same value range but are
of different types.
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(i)
Floating-point number (float type) specifications
Format
The floating-point number format is shown below.
(Higher address)
s
e
m
(Lower address)
31 30
23 22
0
The numerical values in this format are as follows.
(Value of sign)
(Value of exponent)
(1)
* (Value of mantissa) *2
s: Sign (1 bit)
0 for a positive number and 1 for a negative number.
e: Exponent (8 bits)
An exponent with a base of 2 is expressed as a 1-byte integer (expressed by two's complement
in the case of a negative), and used after having a further bias of 7FH added. These
relationships are shown in Table 2-4 below.
Table 2-4. Exponent Relationships
Exponent (Hexadecimal)
Value of Exponent
FE
127
81
2
80
1
7F
0
7E
1
01
126
m: Mantissa (23 bits)
The mantissa is expressed as an absolute value, with bit positions 22 to 0 equivalent to the 1st to
23rd places of a binary number. Except for when the value of the floating point is 0, the value of
the exponent is always adjusted so that the mantissa is within the range of 1 to 2 (normalization).
The result is that the position of 1 (i.e. the value of 1) is always 1, and is thus represented by
omission in this format.
Zero expression
When exponent = 0 and mantissa = 0, 0 is expressed as follows.
(Value of sign)
(1)
* 0
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Infinity expression
When exponent = FFH and mantissa = 0,
is expressed as follows.
(Value of sign)
(1)
*
Unnormalized value
When exponent = 0 and mantissa
0, the unnormalized value is expressed as follows.
(Value of sign)
126
(1)
* (Value of mantissa) *2
Remark
The mantissa value here is a number less than 1, so bit
positions 22 to 0 of the mantissa express as is the 1st to
23rd decimal places.
Not-a-number (NaN) expression
When exponent = FFH and mantissa
0, NaN is expressed, regardless of the sign.
Operation result rounding
Numerical values are rounded down to the nearest even number. If the operation result cannot be
expressed in the above floating-point format, round to the nearest expressible number.
If there are two values that can express the differential of the prerounded value, round to an even
number (a number whose lowest binary bit is 0).
Operation exceptions
There are five types of operation exceptions, as shown below.
Table 2-5. List of Operation Exceptions
Exception
Return Value
Underflow
Unnormalized number
Inexact
0
Overflow
Zero division
Operation impossible
Not-a-number (NaN)
Calling the matherr function causes a warning to appear when an exception occurs.
(2) Character types
The character data types include the following three types.
char
signed char
unsigned char
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(3) Incomplete types
The incomplete data types include the following four types.
Arrays with indefinite object size
Structures
Unions
void type
(4) Derived types
The derived types are divided into the following three categories.
Array type
Structure type
Union type
Function type
Pointer type
(a) Aggregate type
The aggregate type is subdivided into two types.
Array type and Structure type. An aggregate type data is a collection of member objects to be taken
successively.
i)
Array type
The array type continuously allocates a collection of member objects called element types. Member
objects all have an area of the same size. The array type specifies the number of element types and the
elements of the array. It cannot create an incomplete type array.
ii)
Structure type
The structure type continuously allocates member objects each differing in size. Each member object
can be specified by name.
(b) Union type
The union type is a collection of member objects that overlap each other in memory. These member objects
differ in size and name and can be specified individually.
(c) Function type
The function type represents a function that has a specified return value. Function type data specifies the
type of return value, the number of parameters, and the type of parameter. If the type of return value is T,
the function is referred to as a function that returns T.
(d) Pointer type
The pointer type is created from a function type object type called a referenced type as well as from an
incomplete type. The pointer type represents an object. The value indicated by the object is used to
reference the entity of a referenced type.
A pointer type data created from the referenced type T is called a pointer to T.
(5) Scalar types
The basic types (arithmetic types) and pointer type are collectively called the scalar types. The scalar types
include the following data types.
char type
Signed integral type
Unsigned integral type
Enumeration type
Floating point type
Pointer type
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2.3.6 Compatible type and composite type
(1) Compatible type
If two types are the same, they are said to be compatible or have compatibility. For example, if two structures,
unions, or enumeration types that are declared in separate translation (compiling) units have the same number of
members, the same member name and compatible member types, they have a compatible type. In this case, the
individual members of the two structures or unions must be in the same order and the individual members
(enumerated constants) of the two enumerated types must have the same values.
All declarations related to the same objects or functions must have a compatible type.
(2) Composite type
A composite type is created from two compatible types. The following rules apply to the composite type.
If either of the two types is an array of known type size, the composite type is an array of that size.
If only one of the types is a function type which has a parameter type list (declared with a prototype), the
composite type is a function prototype that has the parameter type list.
If both types have a parameter type list (i.e., functions with prototypes), the composite type is one with a
prototype consisting of all information that can be combined from the two prototypes.
[Example of composite type]
Assume that two declarations that have file scope are as follows.
int f (int (*) (), double (*) [3] ) ;
int f (int (*) (char *), double (*) [] );
The composite type of the function in this case becomes as follows.
int f (int (*) (char *), double (*) [3] ) ;
2.4 Constants
A constant is a variable that does not change in value during the execution of the program, and its value must be
set beforehand. The type for each constant is determined according to the format and value specified for the
constant. The following four constant types are available.
Floating-point constants
Integer constants
Enumeration constants
Character constants
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2.4.1 Floating-point constant
A floating-point constant consists of an effective digit part, exponent part, and floating-point suffix.
Effective digit part:
Integer part, decimal point, and fraction part
Exponent part:
e or E, signed exponent
Floating-point suffix: f/F (float)
I/L (long double)
If omitted (double)
The signed exponent of the exponent part and the floating-point suffix can be omitted.
Either the integer part or fraction part must be included in the effective digits. Also, either the decimal point or
exponent part must be included (example: 1.23F, 2e3).
2.4.2 Integer constant
An integer constant starts with a number and does not have a decimal point or exponent part. An unsigned suffix
can be added after the integer constant to indicate that the integer constant is unsigned. A long suffix can be added
after the integer constant to indicate that the integer constant is long.
There are the following three types of integer constants.
Decimal constant:
Decimal number that starts with a number other than 0
Decimal number = 123456789
Octal constant:
Integer suffix 0 + octal number
Octal number = 01234567
Hexadecimal constant: Integer suffix 0x or 0X + hexadecimal number
Hexadecimal number = 0123456789
abcdef ABCDEF
Unsigned suffix
u U
Long suffix
l L
(1) Decimal constant
A decimal constant is an integer value with a base (radix) of 10 and must begin with a number other than 0
followed by any numbers 0 through 9 (example: 56UL).
(2) Octal constant
An octal constant is an integer value with a base of 8 and must begin with 0 followed by any numbers 0 through
7 (example: 034U).
(3) Hexadecimal constant
A hexadecimal constant is an integer value with the base of 16 and must begin with 0x or 0X followed by any
numbers 0 through 9 and a through f or A through F, which represent 10 through 15 (example: 0xF3).
The type of integer constant is regarded as the first of the "representable type" shown below.
In this compiler, the type of the unsubscripted constant can be changed to char or unsigned char depending on
the compile condition (option).
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(Integer constant)
(Representable type)
Unsuffixed decimal number .................................. int, long int, unsigned long int
Unsuffixed octal, hexadecimal number................. int, unsigned int, long int, unsigned long int
Suffixed u or U...................................................... unsigned int, unsigned long int
Suffixed l or L........................................................ long int, unsigned long int
Suffixed u or U, and suffixed l or L ....................... unsigned long int
2.4.3 Enumeration constants
Enumeration constants are used for indicating an element of an enumeration type variable, that is, the value of an
enumeration type variable that can have only a specific value indicated by an identifier.
The enumeration type (enum) is whichever is the first type from the top of the list of three types shown below that
can represent all the enumeration constants. The enumeration constant is indicated by the identifier.
signed char
unsigned char
signed int
It is described as `enum enumeration type {list of enumeration constant}'.
Example enum months {January = 1, February, March, April, May};
When the integer is specified with =, the enumeration variable has the integer value, and the
following value of enumeration variable has that integer value + 1. In the example shown above,
the enumeration variable has 1, 2, 3, 4, 5, respectively. When there is not `= 1', each constant has
0, 1, 2, 3, 4, 5, respectively.
2.4.4 Character constants
A character constant is a character string that includes one or more characters enclosed in a pair of single quotes
as in `X' or `ab'.
A character constant does not include single quote', backslash ( or \), and line feed character (n). To represent
these characters, escape sequences are used. There are the following three types of escape sequences.
Simple escape sequence:
\'
\"
\?
\
\a
\b
\f
\n
\r
\t
\v
Octal escape sequence:
\octal number [octal number octal number]
(example: \012, \0
Note 1
)
Hexadecimal escape sequence : \x hexadecimal number
(example: \xFF
Note 2
)
Notes 1.
Null character
2.
In this compiler, \xFF represents 1. If the condition (option) that regards char as unsigned char is
added, however, it represents +255.
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2.5 String Literals
A string literal is a string of zero or more characters enclosed in a pair of double quotes as in "xxx". (Example:
"xyz")
A single quote (') is represented by the single quotation mark itself or by the escape sequence \', whereas a
double quote (") is represented by the escape sequence \".
Array elements have a char type string literal and are initialized by assigned tokens (example: char array [ ] =
"abc";).
2.6 Operators
The operators are shown below.
[ ]
( )
.
->
++
- -
&
*
+
~
!
sizeof
/
%
<<
>>
<
>
<=
>=
==
!=
^
|
&&
||
?
:
=
*=
/=
%=
+=
-=
<<=
>>=
&=
^=
|=
,
#
##
The [ ], ( ), and ?: operators must always be used in pairs.
An expression may be described in brackets "[ ]", in parentheses "( )", or between "?" and ":".
The # and ## operators are used only for defining macros in preprocessings. (For the description, refer to
CHAPTER 5 OPERATORS AND EXPRESSIONS.)
2.7 Delimiters
A delimiter is a symbol that has an independent syntax or meaning. However, it never generates a value.
The following delimiters are available for use in C.
[ ]
( )
{ }
*
,
:
=
;
...
#
An expression declaration or statement may be described in brackets "[ ]", parentheses "( )", or braces "{ }",
These delimiters must always be used in pairs as shown above. The delimiter # is used only for preprocessings.
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2.8 Header Name
A header name indicates the name of an external source file. This name is used only in the preprocessing
directive "#include".
An example of the #include directive header name is shown below. For details of each #include directive, refer
to 9.2 Source File Inclusion Directive.
#include
<header name>
#include
"header name"
2.9 Comment
A comment refers to a statement to be included in a C source module for information only. It begins with "/*" and
ends with "*/". The part after "//" to the line feed can be identified as a comment statement using the ZP option.
Example /* comment statement */
//comment statement
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CHAPTER 3 DECLARATION OF TYPES AND STORAGE CLASSES
This chapter explains how data (variables) or functions to be used in C should be declared as well as the scope
for each data or function. A declaration means the specification of an interpretation or attribute for an identifier or a
collection of identifiers. A declaration to reserve a storage area for an object or function named by an identifier is
referred to as a "definition".
An example of a declaration is shown below.
#define
TRUE 1
#define
FALSE
0
#define
SIZE 200
void main(void)
{
auto int i, prime,
k;
/* declaration of automatic variables */
for ( i = 0 ; i <= SIZE ; i++)
mark [i] = TRUE ;
.
.
.
A declaration is configured with a storage class specifier, type specifier, initialize declarator, etc. The storage
class specifier and type specifier specify the linkage, storage duration, and the type of entity indicated by the
declarator. An initialize declarator list is a list of declarators delimited with a comma. Each declarator may have
additional type information or initializer or both.
If an identifier for an object is declared to have no linkage, the type of the object must be perfect (the object with
information related to the size) at the end of the declarator or initialize declarator (if it has an initializer).
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3.1 Storage Class Specifiers
A storage class specifier specifies the storage class of an object. It indicates the storage location of a value that
the object has, and the scope of the object. In a declaration, only one storage class specifier can be described. The
following five storage class specifiers are available.
typedef
extern
static
auto
register
(1) typedef
The typedef specifier declares a synonym for the specified type. See 3.6 below for details of the typedef
specifier.
(2) extern
The extern specifier indicates (tells the compiler) that the variable immediately before this specifier is declared
elsewhere in the program (i.e., an external variable).
(3) static
The static specifier indicates that an object has static storage duration. For an object that has static storage
duration, an area is reserved before the program execution and the value to be stored is initialized only once.
The object exists throughout the execution of the entire program and retains the value last stored in it.
(4) auto
The auto specifier indicates that an object has automatic storage duration. For an object that has automatic
storage duration, an area is reserved when the object enters a block to be declared.
At entry into the declared block from its top, the object is initialized if so specified. If the object enters the block
by jumping to a label within the block, the object will not be initialized.
The area reserved for an object that has automatic storage duration will not be guaranteed after the execution of
the declared block.
(5) register
The register specifier indicates that an object is assigned to a register of the CPU. With this C compiler, it is
allocated to the register or saddr area of the CPU. See CHAPTER 11 EXTENDED FUNCTIONS for details of
register variables.
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3.2 Type Specifiers
A type specifier specifies (or refers to) the type of an object. The following type specifiers are available.
void
char
short
int
long
float
double
long double
signed
unsigned
structure
or union specifier
enumeration
specifier
typedef
name
In this C compiler, the following type specifiers have been added.
bit/boolean/_ _boolean/_ _boolean1
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The following explains the meaning of each type specifier and the limit values that can be expressed with this
compiler (the values enclosed in the parentheses). Since this compiler supports only the single precision of IEEE Std
754-1985 for floating-point operations, double and long double data are regarded to have the same format as those
of float data.
void
............................................................... Collection of null values
char
............................................................... Size of the basic character set that can be stored
signed char
................................................ Signed integer (128 to +127)
unsigned char
............................................ Unsigned integer (0 to 255)
short, signed short, short int,
signed short int
........................................ Signed integer (32768 to +32767)
unsigned short, unsigned short int
Unsigned integer (0 to 65535)
int, signed, signed int
...................... Signed integer (32768 to +32767)
unsigned, unsigned int
........................ Unsigned integer (0 to 65535)
long, signed long, long int,
signed long int
........................................ Signed integer (2147483648 to +2147483647)
unsigned long, unsigned long int
... Unsigned integer (0 to 4294967295)
float
............................................................. Single precision floating-point number (1.17549435E38F to
3.40282347E+38F)
double
........................................................... Double precision floating-point number (1.17549435E38F to
3.40282347E+38F)
long double
................................................ Extended precision floating-point number (1.17549435E38F to
3.40282347E+38F)
structure/union
specifier ........................ Collection of member objects
enumeration
specifier ................................ Collection of int type constants
typedef
name ............................................. Synonym of specified type
bit/boolean/_ _boolean/_ _boolean1
Integers represented with a single bit (0 to 1)
Type specifiers delimited with a comma have the same size.
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3.2.1 Structure specifier and union specifier
Both the structure specifier and union specifier indicate a collection of named members (objects). These member
objects can have different types from one another.
(1) Structure specifier
The structure specifier declares a collection of two or more different types of variables as one object. Each type
of object is called a member and can be given a name. For members, continuous areas are reserved in the
order of their declaration.
Align data is inserted by specifying the -RP option.
A structure is declared as follows. The declaration will not yet allocate memory since it does not have a list of
structure variables. For the definition of the structure variables, refer to CHAPTER 7 STRUCTURES AND
UNIONS.
struct
identifier {member declaration list};
Example of structure declaration
struct tnode {
int count;
struct tnode *left, *right;
};
(2) Union specifier
The union specifier declares a collection of two or more different types of variables as one object. Each type of
object is called a member and can be given a name. The members of a union overlap each other in area,
namely, they share the same area.
A union is declared as follows. The declaration will not yet allocate memory since it does not have a list of union
variables. For the definition of the union variables, refer to CHAPTER 7 STRUCTURES AND UNIONS.
union
identifier {member declaration list};
Example of union declaration
union
u_tag
{
int var1 ;
long var2 ;
};
Each member object can be any type other than the incomplete types or function types. A member can be
declared with the number of bits specified. A member with the number of bits specified is called a bit field.
In this compiler, extended functions related to bit field declaration have been added. For details, refer to 11.5
(19) Bit field declaration.
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(3) Bit field
A bit field is an integral type area consisting of a specified number of bits. For the bit field, int type, unsigned int
type, and signed int type data can be specified.
Note 1
The MSB of an int field which has no qualifier or a signed
int field will be judged as a sign bit.
Note 2
If two or more bit fields exist, the second and subsequent bit fields are packed into the adjacent bit positions,
provided there is an ample space within the same memory unit. By placing an unnamed bit field with a width of
0, the next bit field will not be packed into a space within the same memory unit. An unnamed bit field has no
declarator and declares a colon and a width only.
The unary & operator (address) cannot be applied to a bit field object.
Notes 1.
In this compiler, char type, unsigned char type, and signed char type can also be specified. All of
them are regarded as unsigned type since this compiler does not support signed type bit fields.
2.
In this compiler, the direction of bit field allocation can be changed using the compiler option RB (for
details, refer to CHAPTER 11 EXTENDED FUNCTIONS).
The following shows an example of a bit field.
struct data {
unsigned int a:2;
unsigned int b:3;
unsigned int c:1;
} no1 ;
3.2.2 Enumeration specifiers
An enumeration type specifier indicates a list of objects to be put in sequence. Objects to be declared with the
enum specifier will be declared as constants that have int types.
The enumeration specifier is declared as shown below.
enum
[identifier] {enumerator list}
Objects are declared according to an enumerator list. Values are defined for all objects in the list in the order of
their declaration by assigning the value of 0 to the first object and the value of the previous object plus 1 to the 2nd
and subsequent objects. A constant value may also be specified by "=".
In the following example, "hue" is assumed as the tag name of the enumeration, "col" as an object that has this
(enum) type, and "cp" as a pointer to an object of this type. In this declaration, the values of the enumeration
become "{0, 1, 20, 21}".
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enum hue {
chartreuse,
burgundy,
claret=20,
winedark
} ;
enum hue col, *cp ;
void main (void) {
col = claret ;
cp = &col ;
/*...*/ (*cp != burgundy) /*...*/
:
3.2.3 Tags
A tag is a name given to a structure, union, or enumeration type. A tag has a declared data type and objects of
the same type can be declared with a tag.
The identifier in the following declaration is a tag name.
structure/union identifier {member declaration list}
or
enum
identifier {enumerator list}
A tag has the contents of the structure/union or enumeration defined by a member. In the next and subsequent
declarations, the structure of a struct, union, or enum type becomes the same as that of the tag's list. In the
subsequent declarations within the same scope, the list enclosed in braces must be omitted. The following type
specifier is undefined with respect to its contents and thus the structure or union has an incomplete type.
struct/union identifier
A tag to specify the type of this type specifier can be used only when the object size is unnecessary. This is
because by defining the contents of the tag within the same scope, the type specification becomes incomplete.
In the following example, the tag "tnode" specifies a structure that includes pointers to an integer and two objects
of the same type.
struct tnode {
int count;
struct tnode *left, *right ;
};
The next example declares "s" as an object of the type indicated by the tag (tnode) and "sp" as a pointer to the
object of the type indicated by the tag. By this declaration, the expression "sp
left" indicates a pointer to "struct
tnode" on the left of the object pointed to by "sp" and the expression "s.right
count" indicates "count", which is a
member of "struct tnode" on the right of "s".
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typedef struct tnode TNODE;
struct tnode {
int count ;
struct tnode *left, *right ;
};
TNODE s *sp;
void main (void) {
sp
left = sp right;
s.right
count = 2;
}
3.3 Type Qualifiers
Two type qualifiers are available: const and volatile. These type qualifiers affect left-side values only.
Using a left-side value that has a non-const type qualifier cannot change an object that has been defined with a
const type qualifier. Using a left-side value that has a non-volatile type qualifier cannot reference an object that has
been defined with a volatile type qualifier.
An object that has a volatile qualifier type can be changed by a method not recognizable by the compiler or may
have other unnoticeable side effects. Therefore, an expression that references this object must be strictly evaluated
according to the sequence rules that regulate abstractly how programs written in C should be executed. In addition,
the values to be stored last in the object at every sequence point must be in agreement with those determined by the
program, except for the changes due to factors unrecognizable by the compiler as mentioned above.
If an array type is specified with type qualifiers, the qualifiers apply to the array members, not the array itself.
No type qualifier can be included in the specification of a function type. However, callt, _ _ callt, callf, _ _ callf,
noauto, norec, _ _ leaf, _ _ interrupt, _ _ interrupt_brk, _ _rtos_interrupt, _ _pascal, which are the type qualifiers
unique to this compiler mentioned in 2.1 Keywords, can be included as type qualifiers.
sreg, _ _sreg, _ _sreg1, and _ _directmap are also type qualifiers.
In the following example, "real_time_clock" can be changed by hardware, but operations such as assignment,
increment, and decrement are not possible.
extern const volatile int real_time_clock;
An example of modifying aggregate type data with type qualifiers is shown below.
const struct s { int mem;} cs = { 1 };
struct s ncs;
/* object ncs is changeable */
typedef int A [2][3];
const A a = { {4, 5, 6}, {7, 8, 9} };
/* array of const int array */
int *pi;
const int *pci;
ncs = cs;
/* correct */
cs = ncs;
/* violates restriction of left-side value which has modifiable assignment operator */
pi = &ncs. mem;
/* correct */
pi = &cs. mem;
/* violates restriction of the type of assignment operator = */
pci = &cs. mem;
/* correct */
pi = a[0];
/* incorrect:a[0] has "const int *" type */
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3.4 Declarators
A declarator declares an identifier. Here, pointer declarators, array declarators, and function declarators are
mainly discussed. The scope of an identifier and a function or object that has a storage duration and a type are
determined by a declarator.
A description of each declarator is given below.
3.4.1 Pointer declarators
A pointer declarator indicates that an identifier to be declared is a pointer. A pointer points to (indicates) the
location where a value is stored. Pointer declaration is performed as follows.
* type qualifier list identifier
By this declaration, the identifier becomes a pointer to T1.
The following two declarations indicate a variable pointer to a constant value and an invariable pointer to a
variable value, respectively.
const int *ptr_to_constant;
int *const constant_ptr;
The first declaration indicates that the value of the constant "const int" pointed by the pointer "ptr_to_constant"
cannot be changed, but the pointer "ptr_to_constant" itself may be changed to point to another "const int". Likewise,
the second declaration indicates that the value of the variable "int" pointed by the pointer "constant_ptr" may be
changed, but the pointer "constant_ptr" itself must always point to the same position.
The declaration of the invariable pointer "constant_ptr" can be made distinct by including a definition for the
pointer type to the int type data.
The following example declares "constant_ptr" as an object that has a const qualifier pointer type to int.
typedef int *int_ptr;
const int_ptr constant_ptr;
3.4.2 Array declarators
An array declarator declares to the compiler that an identifier to be declared is an object that has an array type.
Array declaration is performed as shown below.
type
identifier [constant expression]
By this declaration, the identifier becomes an array that has the declared type. The value of the constant
expression becomes the number of elements in the array. The constant expression must be an integer constant
expression which has a value greater than 0. In the declaration of an array, if a constant expression is not specified,
the array becomes an incomplete type.
In the following example, a char type array "a[ ]", which consists of 11 elements and a char type pointer array
"ap[ ]", which consists of 17 elements, have been declared.
char a[11], *ap[17];
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In the following two examples of declarations, "x" in the first declaration specifies a pointer to an int type data and
"y" in the second declaration specifies an array to an int type data which has no size specification and is to be
declared elsewhere in the program.
extern int *x;
extern int y [ ];
3.4.3 Function declarators (including prototype declarations)
A function declarator declares the type of return value, argument, and the type of the argument value of a function
to be referenced.
Function declaration is performed as follows.
type identifier (parameter list or identifier list)
By this declaration, the identifier becomes a function that has the parameter specified by the parameter type list
and returns the value of the type declared before the identifier. Parameters of a function are specified by a
parameter identifier list. By these lists, an identifier, which indicates the argument and its type, are specified. A
macro defined in the header file "stdarg.h" converts the list described by the ellipsis (, ...) into parameters. For a
function that has no parameter specification, the parameter list will become "void ".
3.5 Type Names
A type name is the name of a data type that indicates the size of a function or object. Syntax-wise, it is a function
or object declaration less identifiers.
Examples of type names are given below.
int .............................
Specifies an int type.
int * ...........................
Specifies a pointer to an int type.
int *[3] .......................
Specifies an array that has three pointers to an int type.
int (*) [3]....................
Specifies a pointer to an array that has three int types.
int *( ).......................
Specifies a function that returns a pointer to an int type that has no parameter
specification.
int (*) (void)...............
Specifies a pointer to a function that returns an int type that no parameter specification.
int (*const [ ]) (unsigned int, ...) .... Specifies an indefinite number of arrays that have one parameter of unsigned
int type and an invariable pointer to each function that returns an int type.
3.6 typedef Declarations
The typedef keyword defines that an identifier is a synonym to a specified type. The defined identifier becomes a
typedef name.
The syntax of typedef names is shown below.
typedef
type identifier;
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In the following example, "distance" is an int type, the type of "metricp" is a pointer to a function that returns an int
type that has no parameter specification, the type of "z" is a specified structure, and "zp" is a pointer to this structure.
typedef int MILES, KLICKSP ();
typedef struct {long re, im} complex;
/*...*/
MILES distance;
extern KLICKSP *metricp;
complex z, *zp;
In the following example, the typedef name t is declared with a signed int type, and the typedef name plain is
declared with an int type, and a structure with three bit field members is declared. The bit field members are as
follows.
Bit field member with name t and the value 0 to 15
Bit field member without a name and the const qualified value 16 to +15 (if accessed)
Bit field member with name r and the value 16 to +15
typedef signed int t;
typedef int plain;
struct tag {
unsigned t:4;
const t:5;
plain r:5;
};
In this example, these two bit field declarations differ in that the first bit field declaration has unsigned as the type
specifier (therefore, t becomes the name of the structure member), and the second bit field declaration, on the other
hand, has const as the type qualifier (qualifies t which can be referred to as the typedef name). After this
declaration, if:
t f(t (t));
long t;
is found within the effective range, the function f is declared as "function that has one parameter and returns signed
int", and the parameter is declared as "pointer type for the function that has one parameter and returns signed int".
The identifier t is declared as long type.
typedef names may be used to facilitate program reading. For example, the following three declarations for the
function signal all specify the same type as the first declaration which does not use typedef.
typedef void fv(int) ;
typedef void (*pfv) (int) ;
void (*signal (int, void (*) (int)))(int);
fv *signal(int, fv *);
pfv signal(int, pfv);
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3.7 Initialization
Initialization refers to setting a value in an object beforehand. An initializer carries out the initialization of an
object.
Initialization is performed as follows.
object = {initializer list}
An initializer list must contain initializers for the number of objects to be initialized.
All expressions in initializers or an initializer list for objects that have static storage duration and objects that have
an aggregate type or a union type must be specified with constant expressions.
Identifiers that declare block scope but have external or internal linkage cannot be initialized.
(1) Initialization of objects which have a static storage duration
If no attempt is made to initialize an arithmetic type object that has static storage duration, the value of the object
will be implicitly initialized to 0.
Likewise, a pointer type object that has a static storage duration will be initialized to a null pointer constant.
Example
unsigned int gval1;
/* initialized by 0 */
static int gval2;
/* initialized by 0 */
void func (void) {
static char aval;
/* initialized by 0 */
}
(2) Initialization of objects that have an automatic storage duration
The value of an object that has automatic storage duration becomes undefined and will not be guaranteed if it is
not initialized.
Example
void func(void){
char aval;
/*undefined at this point */
:
aval = 1;
/* initialized to 1 */
}
(3) Initialization of character arrays
A character array can be initialized by a char string literal (char string enclosed with " "). Likewise, a character
string in which a series of char string literals are contained initializes the individual members or elements of an
array.
In the following example, the array objects "s" and "t" with no type qualifier are defined and the elements of each
array will be initialized by a char string literal.
char s[ ] = "abc", t[3] = "abc" ;
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The next example is the same as the above example of array initialization.
Char s[ ] = {`a', `b', `c', `\0'},
t[ ] = { `a', `b', `c'};
The next example defines p as "pointer to char" type and the member is initialized by a character string literal so
that the length indicates 4 "char array" type objects.
char *p = "abc" ;
(4) Initialization of aggregate or union type objects
Aggregate type
An aggregate type object is initialized by a list of initializers described in ascending order of subscripts or
members. The initializer list to be specified must be enclosed in braces.
If the number of initializers in the list is less than the number of aggregate members, the members not
covered by the initializers will be implicitly initialized just the same as an object that has static storage
duration.
With an array of an unknown size, the number of its elements is governed by the number of initializers and the
array will no longer become an incomplete type.
Union type
A union type object is initialized by an initializer for the first member of the union that is enclosed in braces.
In the following example, the array "x" with an unknown size will change to a one-dimensional array that has
three elements as a result of its initialization.
int x[ ] = {1, 3, 5} ;
The next example shows a complete definition which has initializers enclosed in braces. "{1, 3, 5}" initializes
"y [0] [0]", "y [0] [1]", and "y [0] [2]" in the 1st line of the array object "y[0]". Likewise, in the second line, the
elements of the array objects "y [1]" and "y [2]" are initialized. The initial value of "y[3]" is 0 since it is not
specified.
char y [4] [3] = {
{1, 3, 5},
{2, 4, 6},
{3, 5, 7},
};
The next example produces the same result as the above example.
char z[4][3] = {
1, 3, 5, 2, 4, 6, 3, 5, 7
};
CHAPTER 3 DECLARATION OF TYPES AND STORAGE CLASSES
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In the following example, the elements in the first row of "z" are initialized to the specified values and the rest of
the elements are initialized to 0.
char z[4] [3] = {
{1}, {2}, {3}, {4}
};
In the next example, a three-dimensional array is initialized.
q[0] [0] [0] are initialized to 1, q[1] [0] [0] to 2, and q[1] [0] [1] to 3. 4, 5 and 6 initialize q[2] [0] [0], q[2] [0] [1], and
q[2] [1] [0], respectively. The rest of the elements are all initialized to 0.
short q[4] [3] [2] = {
{1],
{2, 3}
{4, 5, 6}
};
The following example produces the same result as the above initialization of the three-dimensional array.
short q[4][3][2] = {
1, 0, 0, 0, 0, 0,
2, 3, 0, 0, 0, 0,
4, 5, 6
};
The following example shows a complete definition of the above initialization using braces.
Short q [4][3][2] = {
{
{1},
},
{
{2, 3},
},
{
{4, 5, 6},
}
};
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CHAPTER 4 TYPE CONVERSIONS
In an expression, if two operands differ in data type, the compiler automatically performs a type conversion
operation. This conversion is similar to a change obtained by the cast operator. This automatic type conversion is
called an implicit type conversion. In this chapter, this implicit type conversion is explained.
Type conversion operations include usual arithmetic conversions, conversions involving truncation/round off, and
conversions involving sign change. Table 4-1 gives a list of conversions between types.
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Table 4-1. List of Conversions Between Types
After Conversion
Before Conversion
(signed)
char
unsigned
char
(signed)
short int
unsigned
short int
(signed)
int
unsigned
int
(signed)
long int
unsigned
long int
float
double
long
double
(signed) char
+
N
N
N
N
unsigned char
(signed) short int
+
N
N
N
unsigned short int
(signed) int
+
N
N
N
unsigned int
(signed) long int
+
N
unsigned long int
float
double
long double
Remarks 1
The signed keyword may be omitted. However, with a char type data, the data type is regarded as
the signed char or unsigned char type depending on the condition (option) for compilation.
2
Legend:
:
Type conversion will be performed properly.
\:
Type conversion will not be performed.
N:
A correct value will not be generated. (The data type will be regarded as an unsigned int
type.)
:
The data type will not change bit-image-wise. However, if a positive number cannot
represent it sufficiently, no correct value will be generated (regarded as an unsigned
integer).
Blank:
An overflow in the result of the conversion will be truncated. The + or sign of the data
may be changed depending on the type after the conversion.
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4.1 Arithmetic Operands
(1) Characters and integers (general integral promotion)
The data types of char, short int, and int bit fields (whether they are signed or unsigned) or of objects that have
an enumeration type will be converted to int types if their values are within the range that can be represented
with int types. If not within the range, they will be converted to unsigned int types. These implicit type
conversions are referred to as "general integral general promotion". All other arithmetic types will not be
changed by this general integral promotion.
In general integral promotion, the value of the original data type is retained, including its sign. char type data
without a type qualifier will normally be handled as signed char in this compiler.
If can also be handled as unsigned char by using an option.
(2) Signed integers and unsigned integers
When a value with an integer type is converted to another, the value will not be changed if the value can be
expressed by the integer type after conversion.
When a signed integer is converted to an unsigned integer of the same or larger size, the value is not changed
unless the value of the signed integer is negative. If the value of the signed integer is negative and the unsigned
integer has a size larger than that of the signed integer, the signed integer is expanded to the signed integer with
the same size as the unsigned integer, and then it is added to the value equal to the maximum number that can
be expressed with the unsigned integer plus 1, and the signed integer before conversion is converted to the
unsigned value.
When a value with an integer type is converted to an unsigned integer with a smaller size, the conversion result
is the non-negative remainder of the value divided with that value which 1 is added to the maximum number that
can be expressed with an unsigned integer after conversion. When a value with an integer type is converted to a
signed integer with smaller size or when an unsigned integer is converted to a signed integer with the same size,
the overflowed value is ignored if the value after conversion cannot be expressed. For the conversion pattern,
refer to Table 4-1. List of Conversions between Types.
Conversion operations from signed integral type to unsigned integral type are as listed in Table 4-2 below.
Table 4-2. Conversions from Signed Integral Type to Unsigned Integral Type
unsigned
Smaller in Value Range
Greater in Value Range
+
/
signed
/
+
: Type conversion will be performed properly.
+: The data will be converted to a positive integer.
/: The result of the conversion will be the remainder of the integer value, modulo the largest
possible value of the type to be converted plus 1.
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(3) Usual arithmetic type conversions
Types obtained as a result of operations on arithmetic type data have a wide range of values.
The type conversion of the operation result is performed as follows.
If either one of the operands has long double type, the other operand is converted to long double type.
If either one of the operands has double type, the other operand is converted to double type.
If either one of the operands has float type, the other operand is converted to float type.
In cases other than above, general integer expansion is performed for both operands according to the following
rules. Figure 4-1 shows the rules.
Figure 4-1. Usual Arithmetic Type Conversions
unsigned long int
unsigned int
int
long int
If either of the two operands is unsigned long int type, or if one
operand is long int type and the other is unsigned int type
and the value of unsigned int type cannot be represented by long int type.
both operands will be converted to unsigned long int type.
In cases other than above, if one operand is long int type and if the value of
the other operand can be represented by long int type, the other operand will be
converted to long int type.
In cases other than above, if one operand is unsigned int type, the other operand
will be converted to unsigned int type.
In cases other than above, both operands will have int type.
In this compiler, the conversion to int type can be intentionally disabled by a compile condition (optimizing
option) (For details, refer to CC78K4 C Compiler Operation User's Manual (U15557E) CHAPTER 5
COMPILER OPTIONS).
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4.2 Other Operands
(1) Left-side values and function locators
A left-side value refers to an expression that specifies an object (and has an incomplete type other than object
type or void type).
Left-side values that do not have array types, incomplete types, or const qualifier types, and structures or unions
that have no const qualifier type members are "modifiable left-side values".
A left-side value that has no array type will be converted to a value stored in the object to be specified, except
when it is the operand of the sizeof operator, unary & operator, ++ operator, or - - operator or the left operand of
an operator or an assignment operator. By being converted, it will no longer serve as a left-side value.
The behavior of left-side values that have incomplete types but have no array types is not guaranteed.
A left-side value that has an "... array" type except character arrays will be converted to an expression that has a
"pointer to ..." type. This expression is no longer a left-side value.
A function locator is an expression that has a function type. With the exception of the operand of the sizeof
operator or unary & operator, a function locator that has a "function type that returns ..." will be converted to an
expression that has a "pointer type to a function that returns ...".
(2) void
The value (non-existent) of a void expression (i.e., an expression that has the void type) cannot be used in any
way. Neither implicit nor explicit conversion to exclude void will be applied to this expression. If an expression
of another type appears in a context that requires a void expression, the value of the expression or specifier is
assumed to be non-existent.
(3) Pointers
A void pointer can be converted to a pointer to any incomplete type or object type. Conversely, a pointer to any
incomplete type or object type can be converted to a void pointer. In either case, the result value must be equal
to that of the original pointer.
An integer constant expression that has the value of 0 and has been cast to the void * type is referred to as a
"null pointer constant". If the null pointer constant is substituted with, equal to, or compared with some pointer,
the null pointer constant will be converted to that pointer.
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CHAPTER 5 OPERATORS AND EXPRESSIONS
This chapter describes the operators and expressions to be used in the C language.
C has an abundance of operators for arithmetic, logical, and other operations. This rich set of operators also
includes those for bit and address operations.
An expression is a string or combination of an operator and one or more operands. The operator defines the
action to be performed on the operand(s) such as computation of a value, instructions on an object or function,
generation of side effects, or a combination of these.
Examples of operators are given below.
#define
TRUE
1
#define
FALSE
0
#define
SIZE
200
void lprintf(char *, int);
void putchar(char c);
char mark [SIZE+1];
+ ...................................................................
Arithmetic operator
void main(void) {
int i, prime, k, count;
count = 0;
=..............................................................
Assignment operator
for (i = 0 ; i <= SIZE ; i++)
++ .............................................
Postfix operator
mark [i] = TRUE;
<= .............................................
Relational operator
for
(i = 0 ; i <= SIZE ; i++) {
if (mark [i]) {
prime = i + i + 3;
+ ...............................................
Arithmetic operator
lprintf ("%d" , prime);
count++;
++ .............................................
Postfix operator
if ((count%8) == 0)
==.............................
Relational operator
putchar ('\n');
for
(k = i + prime ; k<=SIZE; k += prime)
+= ......
Assignment operator
mark [k] = FALSE;
}
}
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lprintf("Total %d\n", count);
loop1:
goto loop1;
}
lprintf(char *s, int;) {
int j;
char *ss;
j = i;
ss = s;
}
void puttchar(char c){
char d;
d = c;
}
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Table 5-1 shows the evaluation priority of operators used in C.
Table 5-1. Evaluation Precedence of Operators
Type of Expression
Operator
Linkage
Priority
Postfix
[ ] ( ) . > ++
Highest
Unary
++ & * + ~ ! sizeof
Cast
(type)
Multiplicative
* / %
Additive
+
Bitwise shift
<< >>
Relational
< > <= >=
Equality
== !=
Bitwise AND
&
Bitwise XOR
^
Bitwise OR
|
Logical AND
&&
Logical OR
| |
Conditional
? :
Assignment
= *= /= %= += =
<<= >>= &= ^= | =
Comma
,
Lowest
The arrow (
or ) in the "Linkage" column denotes that when an expression
contains two or more operators of the same priority, the operations are carried out in
the direction of the arrow "
" (from left to right) or "" (from right to left).
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5.1 Primary Expressions
Primary expressions include the following.
Identifier declared as object or function
(identifier primary expression)
Constant (constant primary expression)
String literal (constant primary expression)
Expression enclosed in parentheses
(parenthesized expression)
An identifier that becomes a primary expression is a left-side value if an object is declared or a function locator if a
function is declared. The data type of a constant is determined according to the value specified for the constant as
explained in 2.4 Constants. String literal(s) become a left-side value that has a data type as explained in 2.5 String
Literals.
5.2 Postfix Operators
A postfix operator is an operator that appears or is placed after an object or function.
The primary expressions are described below.
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(1) Subscript operators
Postfix Operators
[ ] Subscript Operator
FUNCTION
The [ ] subscript operator specifies or refers to a single member of an array object. The array or expression "E1
[E2]" is evaluated as if it were "(*(E1+(E2)))". In other words, the value of E1 is a pointer to the first member of
the array and E2 (if it is an integer) indicates the E2th member of E1 (counting from 0). With a multidimensional
array, as many subscript operators as the number of dimensions must be connected.
In the following example, x becomes an int type array of 3*5. In other words, x is an array which has three
members each consisting of five int type members.
int x[3][5] ;
A multidimensional array may be specified by connecting subscript operators. Assuming that E is an array of nth
dimension (where n
2) consisting of i*j*...*k, the array can be specified with n number of subscript operators. In
this case, E becomes a pointer to an array of (n 1)th dimension consisting of j*...*k.
SYNTAX
postfix-expression [subscripted expression]
NOTE
A postfix expression must have a ".... pointer to object". The subscripted expression of an array must be
specified with integral type data. The result of the expression will become "....." type.
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(2) Function call operators
Postfix Operators
( ) Function Call
FUNCTION
The postfix ( ) operator calls a function. The function to be called is specified with a postfix expression and
argument(s) to be passed to the function are indicated in parentheses ( ).
The description related to function includes the function prototype declaration, the function definition (the body of
a function), and the function call. The function prototype declaration specifies the value a function returns, the
type of argument, and the storage class.
If the function prototype declaration is not referred to in a function call, each argument is extended with a general
integer. This is called "default actual argument extension". Performing a function prototype declaration avoids
default actual argument extension and detects errors in of the type and number of arguments and the type of
return value.
Calling a function that has neither a storage class specification nor a data type specification such as "identifier (
);" is interpreted as calling a function that has an external object and returns an int type that has no information
on arguments. In other words, the following declaration will be made implicitly.
extern int
identifier ( ) ;
SYNTAX
postfix-expression (argument-expression list);
[Example of function call]
int func (char, int);
/* function prototype declaration */
char a ;
int b, ret;
void main(void){
ret = func(a, b);
/* function call */
}
int func(char c, int i) {
/* function definition */
:
return I;
}
NOTE
A function that returns an object other than array types can be called with this operator. The postfix expression
must be of a pointer type to this function.
In a function call including a prototype, the type of argument must be of a type that can be assigned to the
corresponding parameter(s). The number of arguments must also be in agreement.
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(3) Structure and union member
Postfix Operators
. ->
<1> . (dot) operator
FUNCTION
The . (dot) operator (also called a member operator) specifies the individual members of a structure or union.
The postfix expression is the name of the structure or union object to be specified, and the identifier is the name
of the member.
SYNTAX
postfix-expression . identifier
<2>
(arrow) operator
FUNCTION
The
(arrow) operator (also called an indirect membership operator) specifies the individual members of a
structure or union. The postfix expression is the name of the pointer to the structure or union object to be
specified, and the identifier is the name of the member.
SYNTAX
postfix-expression
identifier
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Postfix Operators
. ->
[Examples of `.', `->' operators]
#include <stdlib.h>
union {
struct {
int
type ;
} n ;
struct {
int
type ;
int
intnode ;
} ni ;
struct {
int
type ;
struct {
long
longnode ;
} *nl_p ;
} nl ;
} u ;
void func (void) {
u. nl. type = 1 ;
u. nl.nl_p -> longnode = -31415L ;
/*...*/
if (u.n.type = = 1)
u.nl.nl_p -> longnode = labs (u. nl.nl_p -> longnode) ;
}
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(4) Postfix Increment/Decrement operators
Postfix Operators
++
<1> Postfix ++ (Increment) operator
FUNCTION
The postfix ++ (Increment) operator increments the value of an object by 1. This increment operation is
performed taking the data type of the object into account.
SYNTAX
postfix-expression ++
NOTE
See <2> below.
<2> Postfix (Decrement) operator
FUNCTION
The postfix (Decrement) operator decrements the value of an object by 1. This decrement operation is
performed taking the data type of the object into account.
SYNTAX
postfix expression
NOTE
The operand of the postfix increment or decrement operator must be a modifiable left-side value (qualified or
unqualified).
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5.3 Unary Operators
A unary operator performs an operation on one object or parameter (i.e., operand). The following unary operators
are available.
Prefix Increment and Decrement operators
+ +
Address and Indirect operators
& *
Unary Arithmetic operators
+ ~ !
sizeof operator
sizeof
The followings explain each unary operators are described below.
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(1) Prefix Increment and Decrement operators
Unary Operators
++
<1> Prefix ++ (Increment) operator
FUNCTION
The prefix ++ (Increment) operator increments the value of an object by 1. The expression "++E" of the prefix
increment operator will produce the same result as the following expression.
E = E + 1
or
E+ = 1
SYNTAX
+ +
unary-expression
<2> Prefix (Decrement) operator
FUNCTION
The prefix (Decrement) operator decrements the value of an object by 1. The expression " E" of the prefix
decrement operator will produce the same result as the following expression.
E = E 1
or
E = 1
SYNTAX
unary-expression
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(2) Address and Indirection operators
Unary Operators
& *
<1> Unary & operator
FUNCTION
The unary & (address) operator returns the pointer of a specified object (i.e., the address of the variable it
precedes).
SYNTAX
&
operand
<2> Unary * operator
FUNCTION
The unary * (indirection) operator returns the value indicated by a specified pointer (i.e., takes the value of the
variable it precedes and uses that value as the address of the information in memory).
SYNTAX
*
operand
NOTE
The operand of the unary & operator must be a left-side value referring to an object not declared with the register
storage class specifier. Neither a function locator nor a bit field can be used as the operand of this unary
operator.
The operand of the unary * operator must have a pointer type.
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(3) Unary Arithmetic operators (+ ~ !)
Unary Operators
+ ~ !
FUNCTIONS
The + (unary plus) operator performs positive integral promotion on its operand.
The (unary minus) operator performs negative integral promotion on its operand.
The ~ (tilde) operator is a bitwise one's complement operator which inverts all the bits in a byte of its operand.
The ! NOT or logical negation operator returns 0 if its operand is 0 and 1 if it is not 0. In other words, the
operator changes each 0 to 1 and 1 to 0.
SYNTAX
+
operand
operand
~
operand
!
operand
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(4) sizeof operators
Unary Operators
sizeof Operator
FUNCTION
The sizeof operator returns the size of a specified object in bytes. The return value is governed by the data type
of the object and the value of the object itself is not evaluated.
The value to be returned by an unsigned char or signed char object (including its qualified type) on which a
sizeof operation is performed is 1. With an array type object, the return value will be the total number of bytes in
the array. With a structure or union type object, the result value will be the total number of bytes that the object
would occupy including bytes necessary to pad out to the next appropriate alignment boundary.
The type of the sizeof operation result is an integral type and its name is size_t. This name is defined in the
<stddef.h> header. The sizeof operator is used mainly to allocate memory areas and transfer data to/from the
I/O system.
SYNTAX
sizeof
unary-expression
or
sizeof
(type-name)
EXAMPLE
The following example finds the number of elements of an array by dividing the total number of bytes in the array
by the size of a single element. Num becomes 5.
int num;
char array[ ]= {0, 1, 2, 3, 4};
void func(void){
num = sizeof array / sizeof array [0] ;
}
NOTE
An expression that has a function type or incomplete type and a left-side value that refers to a bit field object
cannot be used as the operand of this operator.
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5.4 Cast Operators
A cast is a special operator that forces one data type to be converted into another. The cast operator is mainly
used when converting a pointer type.
Cast Operators
(type-name)
FUNCTION
The cast operator converts the data type of another object (or the result of another expression) into the type
specified in parentheses ( ).
SYNTAX
(
type-name) expression
EXAMPLE
void func (void) {
int val;
float f;
f = 3.14F;
val = (int) f;
/* val becomes 3 by cast */
val = *(int *)0x10000;
/* cast constant */
}
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5.5 Arithmetic Operators
Arithmetic operators are divided into multiplicative operators and additive operators. Multiplicative operators find
the product, quotient, and remainder of two operands. Additive operators find the sum and difference of two
operands.
Multiplicative operators
* / %
Additive operators
+
Table 5-2. Signs of Division/Remainder Division Operation Result
a/b
b
a % b
b
+
+
+
+
+
+
+
a
+
a
Remark
a and b indicate operands.
Division is performed with two integers whose sign, if any, is removed through the usual arithmetic conversion and
the result will be truncated towards 0 if necessary. Likewise, a remainder or modulo division operation is performed
with two integers whose sign, if any, is removed through the usual arithmetic conversion. Table 5-2 shows the
results of calculations only on the signs of two operands in division and remainder division, respectively.
Multiplicative operators and additive operators are described below. E1 and E2 used in the explanation of syntax
indicate operands or expressions.
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(1) Multiplicative operators
Multiplicative Operators
* / %
<1> * operator
FUNCTION
The binary * (multiplication) operator performs normal multiplication on two operands and returns the product.
SYNTAX
E1 * E2
<2> / operator
FUNCTION
The / operator performs normal division on two operands and returns the quotient.
SYNTAX
E1 / E2
<3> % operator
FUNCTION
The % operator performs a remainder (or modulo division) operation on two operands and returns the remainder
in the result.
SYNTAX
E1 % E2
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(2) Additive operators
Additive Operators
+
<1> + operator
FUNCTION
The + operator performs addition on two operands and returns the sum of the two numbers.
SYNTAX
E1 + E2
<2> operator
FUNCTION
The operator performs subtraction on two operands and returns the difference between the two numbers (the
first operand minus the second operand).
SYNTAX
E1 E2
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5.6 Bitwise Shift Operators
A shift operator shifts its first (left) operand to the direction (left or right) indicated by the operator by the number of
bits specified by its second operand. There are the following two shift operators.
shift operator << >>
Table 5-3. Shift Operations
a<<b
b
Note
a>>b
b
Note
+
0
+
0
0
1
Note
The table indicates when the right operand is greater than the number of bits in the left operand or
when an overflow occurs in the result of the shift operation.
If the right operand is negative, the value is processed as an unsigned positive number.
Remark
a and b indicate operands.
The shift operators are described below. E1 and E2 indicate operands or expressions.
a
a
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Shift Operators
<< >>
<1> Left shift (<<) operators
FUNCTION
The binary << (left shift) operator shifts the left operand to the left the number of bits specified by the right
operand and fills zeros in vacated bits. If the left operand E1 has an unsigned type in "E1 << E2", the result will
become a value obtained by multiplying E1 by the E2th power of 2.
SYNTAX
E1 << E2
<2> Right shift (>>) operators
FUNCTION
The binary >> (right shift) operator shifts the left operand to the right the number of bits specified by the right
operand. If the left operand is unsigned, zeros are filled in vacated bits (Logical shift). If the left operand is
signed, a copy of the sign bit is filled in vacated bits.
If the left operand E1 is unsigned or signed and has a non-negative value in "E1>>E2", the result will become a
value obtained by dividing E1 by the E2th power of 2.
SYNTAX
E1 >> E2
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5.7 Relational Operators
There are two types of operators to indicate the relationship between two operands: "relational operator" and
"equality operator".
The relational operator indicates the value relationship between two operands such as greater than and less than.
The equality operators indicate that two operands are equal or not equal.
The relational operators and equality operators are shown below.
Relational operator
<
>
<=
>=
Equality operator
==
! =
The value relationship between two pointers compared by relational operators is determined by the relative
location in the address space of the object indicated by the pointer.
In this compiler, relational operators and equality operators generate `1' if the specified relationship is true and `0'
if it is false. The results have int type.
The relational operators and equality operators are described below. E1 and E2 used in the explanation of syntax
indicate operands or expressions.
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(1) Relational operators
Relational Operators
< > <= >=
<1> < (less than) operator
FUNCTION
The < (less than) operator returns 1 if the left operand is less than the right operand; otherwise, 0 is returned.
SYNTAX
E1 < E2
<2> > (greater than) operator
FUNCTION
The > (greater than) operator returns 1 if the left operand is greater than the right operand; otherwise, 0 is
returned.
SYNTAX
E1 > E2
<3> <= (less than or equal) operator
FUNCTION
The <= (less than or equal) operator returns 1 if the left operand is less than or equal to the right operand;
otherwise, 0 is returned.
SYNTAX
E1 <= E2
<4> >= (greater than or equal) operator
FUNCTION
The >= (greater than or equal) operator returns 1 if the left operand is greater than or equal to the right operand;
otherwise, 0 is returned.
SYNTAX
E1 >= E2
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(2) Equality operators
Equality Operators
= = !=
<1> = = (equal) operator
FUNCTION
The = = (equal) operator returns 1 if its two operands are equal to each other; otherwise, 0 is returned.
SYNTAX
E1 == E2
<2> != (not equal) operator
FUNCTION
The != (not equal) operator returns 1 if the operands are not equal to each other; otherwise, 0 is returned.
SYNTAX
E1 != E2
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5.8 Bitwise Logical Operators
Bitwise logical operators perform a specified logical operation on the value of an object in bit units. The bitwise
logical expressions include Bitwise AND (&), Bitwise Exclusive OR ( ^ ), and Bitwise Inclusive OR ( | ).
Each logical operation is indicated by the operators shown below.
Bitwise AND operator
&
Bitwise XOR operator
^
Bitwise OR operator
|
The bitwise logical operators are described below. E1 and E2 used in the explanation of syntax indicate operands
or expressions.
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(1) Bitwise AND operators
Bitwise AND Operators
&
FUNCTION
The binary & operator is a bitwise AND operator that returns an integral value that has "1" bits in positions where
both operands have "1" bits and that has "0" bits everywhere else.
The bitwise AND operator must be specified with an "operator".
Table 5-4. Bitwise AND Operation
Value of Each Bit in Left Operand
1
0
1
1
0
0
0
0
SYNTAX
E1 & E2
Value of
each bit in
right operand
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(2) Bitwise XOR operators
Bitwise XOR Operators
^
FUNCTION
The binary ^ (caret) operator is a bitwise exclusive OR operator that returns an integral value that has a "1" bit in
each position where exactly one of the operands has a "1" bit and that has a "0" bit in each position where both
operands have a "1" bit or both have a "0" bit.
Table 5-5. Bitwise XOR Operation
Value of Each Bit in Left Operand
1
0
1
0
1
0
1
0
SYNTAX
E1 ^ E2
Value of
each bit in
right operand
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(3) Bitwise Inclusive OR operators
Bitwise Inclusive OR Operators
|
FUNCTION
The binary | operator is a bitwise inclusive OR operator that returns an integral value that has a "1" bit in each
position where at least one of the operands has a "1" bit and that has a "0" bit in each position where both
operands have a "0" bit.
Table 5-6. Bitwise OR Operation
Value of Each Bit in Left Operand
1
0
1
1
1
0
1
0
SYNTAX
E1 | E2
Value of
each bit in
right operand
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5.9 Logical Operators
Logical operators perform logical OR and logical AND operations. A logical OR operation is specified with a
logical OR operator, and a logical AND operation is specified with a logical AND operator. Each operator is shown
below.
Logical AND operator
& &
Logical OR operator
| |
Each operand of both the operators returns the value of int type `0' or `1'. The following explains each logical
operator. E1 and E2 used in the explanation of syntax indicate operands or expressions.
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(1) Logical AND operators
Logical AND Operators
&&
FUNCTION
The && operator performs a logical AND operation on two operands and returns a "1" if both operands have
nonzero values. Otherwise, a "0" is returned. The type of the result is int.
Table 5-7. Logical AND Operation
Value of Left Operand
Zero
Nonzero
Zero
0
0
Nonzero
0
1
SYNTAX
E1 && E2
NOTE
This operator always evaluates its operands from left to right. If the value of the left operand is "0", the right
operand is not evaluated.
Value of
right operand
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(2) Logical OR operators
Logical OR Operators
| |
FUNCTION
The | | operator performs a logical OR operation on two operands and returns a "0" if both operands are zero.
Otherwise, a "1" is returned. The type of result is int.
Table 5-8. Logical OR Operation
Value of Left Operand
Zero
Nonzero
Zero
0
1
Nonzero
1
1
SYNTAX
E1 || E2
NOTE
This operator always evaluates its operands from left to right. If the value of the left operand is nonzero, the right
operand is not evaluated.
Value of
each bit in
right operand
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5.10 Conditional Operators
Conditional operators judge the processing to be performed next by the value of the first operand. Conditional
operators judge by `?' and `:'. The conditional operators are described below.
(1) Conditional operators (?, :)
Conditional Operators
? :
FUNCTION
The conditional (?, :) operator evaluates the first operand before the ?. If the value of the first operand is
nonzero, it evaluates the second operand before the colon. If the value of the first operand is zero, it evaluates
the third operand after the colon. The result of the entire conditional expression will be the value of the second
or third operand.
SYNTAX
1st-operand ? 2nd-operand : 3rd-operand
EXAMPLE
#define TRUE 1
#define FALSE 0
char flag ;
int ret ;
ret func () {
ret = flag ? TRUE : FALSE ;
return ret ;
}
NOTE
If both the second and third operand types are arithmetic types, normal arithmetic type conversion is performed
to make them common types. The type of result is the common type. If both the operand types are structure
types or union types, the result becomes those types. If both the operand types are void types, the result is a
void type.
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5.11 Assignment Operators
Assignment operators include a simple assignment expression that stores the right operand in the left operand
and a compound assignment expression that stores the result of an operation on both operands in the left operand.
The assignment operators are shown below.
Assignment Operators
=
*=
/=
%=
+=
=
<<=
>>=
&=
^=
|=
The each assignment operators are described below. E1 and E2 used in the explanation of syntax indicate
operands or expressions.
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(1) Simple assignment operators
Simple Assignment Operators
=
FUNCTION
The = (simple assignment) operator converts the right operand (expression) to the type of the left operand (left-
side value) before the value is stored.
In the following example, the value of an int type to be returned from the function by the type conversion of the
simple assignment expression will be converted to a char type and an overflow in the result will be truncated.
The comparison of the value with "1" will be made after the value is converted back to the int type. If the
variable "c" declared without a qualifier is not interpreted as unsigned char, the result of the variable will not
become negative and its comparison with "1" will never result in equal. In such a case, the variable "c" must be
declared with an int type to ensure complete portability.
int f(void) ;
char c ;
/*...*/ ((c = f ()) == -1) /*...*/
SYNTAX
E1 = E2
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(2) Compound assignment operators
Compound Assignment Operators
*= /= %= += =
<<= >>= &= ^= |=
<1> Compound assignment operators
FUNCTION
The compound assignment operators perform a specified operation on both operands and stores the result in the
left operand. The value to be stored in the left operand will be converted to the type of the left-side value (left
operand). The compound assignment expression "E1 op = E2" (where op indicates a suitable binary operator) is
equivalent to the simple assignment expression "E1 = E1 op (E2)", except that the left-side value (E1) is only
evaluated once. The following compound assignment expressions will produce the same result as the respective
simple assignment expressions on the right.
a
*= b;
a = a * b;
a
/= b;
a = a / b;
a
%= b;
a = a % b;
a
+= b;
a = a + b;
a
= b;
a = a b;
a
<<= b;
a = a << b;
a
>>= b;
a = a >> b;
a
&= b;
a = a & b;
a
^= b;
a = a ^ b;
a
|= b;
a = a | b;
SYNTAX
E1
*=
E2
E1
/=
E2
E1
%=
E2
E1
+=
E2
E1
=
E2
E1
<<=
E2
E1
>>=
E2
E1
&=
E2
E1
^=
E2
E1
|=
E2
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5.12 Comma Operator
(1) Comma operator
Comma Operator
,
FUNCTION
The comma operator evaluates the left operand as a void type (that is, ignores its value) and then evaluates the
right operand. The type and value of the result of the comma expression are the type and value of the right
operand.
In contents where a comma has another meaning (as in a list of function arguments or in a list of variable
initializations), comma expressions must be enclosed in parentheses. In other words, the comma operator
described in this chapter will not appear in such a list.
In the following example, the comma operator finds the value of the second argument of the function "f ( )". The
value of the second argument becomes 5.
int a, c, t;
void main(void)
f(a, (t=3, t+2), c);
}
SYNTAX
E1 , E2
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5.13 Constant Expressions
Constant expressions include general integral constant expressions, arithmetic constant expressions, address
constant expressions, and initialization constant expressions. Most of these constant expressions can be calculated
at translation instead of execution.
In a constant expression, the following operators cannot be used except when they appear inside sizeof
expressions.
Assignment operators
Increment operators
Decrement operators
Function call operator
Comma operator
(1) General integral constant expression
A general integral constant expression has a general integral type. The following operands may be used.
Integer constants
Enumerated value constants
Character constants
sizeof expressions
Floating-point constants
(2) Arithmetic constant expression
An arithmetic constant expression has an integral type. The following operands may be used.
Integer constants
Enumerated value constants
Character constants
sizeof expressions
Floating-point constants
(3) Address constant expression
An address constant expression is a pointer to an object that has a static storage duration or a pointer to a
function locator. Such an expression must be created explicitly using the unary & operator or implicitly using an
expression with an array type or function type. The following operands may be used.
Array subscript operator [ ]
. (dot) operator
(arrow) operator
& address operator
* indirection operator
Pointer casts
However, none of these operators can be used to access the value of an object.
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CHAPTER 6 CONTROL STRUCTURES OF C LANGUAGE
This chapter describes the program control structures of C language and the statements to be executed in C.
Generally speaking, no matter how complicated a process is, it can be expressed with three basic control
structures. These three control structures are: Sequential, Conditional (Selection), and Iteration. Branch is used to
change the flow of a program by force.
(1) Sequential processing
Statements in a program are executed one by one from top to bottom in the order of their description in the
program.
(2) Conditional (selection) processing
According to the status of the program under execution, the next executable statement is selected and executed.
The selection condition is specified in a control statement. The control statement determines which of the two
alternative statement groups or multiway (three or more) alternative statement groups is to be executed.
(3) Looping (iteration) processing
The same processing is executed two or more times. The execution of an executable statement is repeated a
specified number of times in the state indicated by the control statement.
(4) Branch processing
C is forced to exit from the current program flow and control is transferred to a specified label. Program
execution starts from the statement next to the specified label.
There are six types of statements used in C.
Labeled statement ...............................
Causes branch according to the value of the switch statement
and the destination of the goto statement
Compound statement (block) ..............
Collects two or more statements to be processed as one unit
Expression statement ..........................
A statement consisting of an expression and a semicolon
Selection statement .............................
Selects a statement out of several statements according to the
value of the expression
Iteration statement...............................
Repeatedly performs a statement called the body of a loop
until control expression becomes equal to 0
Branch statement ................................
Causes an unconditional branch to a different destination
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A description example of these statements is shown below.
[Description example]
#define SIZE
10
#define TRUE
1
#define FALSE 0
extern void putchar(char) ;
extern void lprintf(char*, int) ;
char
mark [SIZE+1];
void main (void) {
int i, prime, k, count;
count = 0 ;
for (i = 0 ; i <= SIZE ; i++)
............................ /* for .............. Iteration statement */
mark [i] = TRUE ;
for (i = 0 ; i <= SIZE ; i++)
{....................... / * for ............. Iteration statement */
if (mark [i]) {
............................................ / * if ............... Selection statement */
prime = i + i + 3;
lprintf ("%d" , prime);
if ((count%8) == 0) putchar ('\n');
for (k = i + prime ;
k <= SIZE ; k += prime)
/ * if ............... Selection statement * /
mark [k] = FALSE;
}
}
lprintf ("Total %d\n", count);
loop1;
............................................ / * loop1: ....... Labeled statement * /
goto loop1;
............................................ / * goto .......... Branch statement * /
}
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6.1 Labeled Statements
A labeled statement specifies the destination of the switch or goto statement. The switch statement selects the
statement specified by a control expression from among statements with two or more options. The labeled statement
becomes the label of the statement to be executed by the switch statement. The goto statement causes
unconditional branching to the applicable label from the normal flow of processing.
The syntax of labeled statements is given below.
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(1) case label
Labeled Statements
case label
FUNCTION
case labels are used only in the body of a switch statement to enumerate values to be taken by the control
expression of the switch statement.
SYNTAX
case
constant-expression : statement
EXAMPLE 1
int f (void), i;
void main (void) {
/* ... */
switch (f()) {
case 1:
i = i + 4 ;
break ;
case 2:
i = i + 3 ;
break ;
case 3:
i = i + 2 ;
}
/* ... */
}
EXPLANATION
In EXAMPLE 1, if the return value of f( ) is 1, the first case clause (statement) is selected and the expression
"i=i+4" is executed. Likewise, if the return value of f( ) is 2 or 3, the second or third case statement is selected,
respectively. Each break statement in the above example is to break out of the switch body.
As in this example, case labels are used when two or more options are involved.
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Labeled Statements
case label
EXAMPLE 2
int i ;
void main (void) {
/* ... */
i = 2 ;
switch(i) {
case 1:
i = i + 4 ;
case 2:
i = i + 3 ;
case 3:
i = i + 2 ;
}
/* ... */
}
EXPLANATION
In example 2, the processing starts in the second case statement since i is 2. The third statement is also
consecutively performed since the case statement does not include a break statement. Thus, if the constant
expression and the control expression in the case statement match, the programs thereafter are performed
sequentially. A break statement is used to exit the switch statement.
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(2) default label
Labeled Statements
default label
FUNCTION
A default label is a special case label used only in the body of a switch statement to specify a process to be
executed by C if the value of the control expression does not match any of the case constants.
SYNTAX
default :
statement
EXAMPLE
int f (void), i;
switch (f()) {
case 1:
i = i + 4 ;
break ;
case 2:
i = i + 3 ;
break ;
case 3:
i = i +2 ;
default:
i = 1;
}
EXPLANATION
In the above example, if the return value of f( ) is 1, 2, or 3, the corresponding case clause (statement) is
selected and the expression that follows the case label is executed. Each break statement in the above
example is used to break out of the switch body. If the return value of f( ) is other than 1 to 3, the expression
that follows the default label is executed. In this case, the value of i becomes 1.
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6.2 Compound Statements or Blocks
A compound statement or block consists of two or more statements grouped together with enclosing braces and
executed as one unit syntax-wise. In other words, by enclosing zero or more declarations followed by zero or more
statements all in braces, these statements can be processed as a compound statement whenever a single statement
is expected.
6.3 Expression Statements and Null Statements
An expression statement consists of a statement and a semicolon. A null statement consists of only a semicolon
and is used for labels that require a statement and in looping that does not need a body.
The description examples of expression statements and null statements are given below.
As in the following example, for a function to be called as an expression statement merely to obtain side effects,
the value of its return value can be discarded by using a cast expression.
int p(int) ;
void main(void) {
/*...*/
(void)p(0) ;
}
A null statement can be used as the body of a looping statement as shown below.
char *s ;
void main(void) {
/*...*/
while (*s++ != '0') ;
/* */
}
In addition, it can be used to place a label before a brace ( } ) that closes a compound statement as shown below.
void func(void){
/*...*/
while (loop1) {
/*...*/
while (loop2) {
/*...*/
if (want_out)
goto end_loop1 ;
/*...*/
}
end_loop1: ;
}
}
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6.4 Conditional Statements
Conditional (or selection) statements include the if and switch statements. The if or switch statement allows the
program to choose one of several groups of statements to execute, based on the value of the control expression
enclosed in parentheses.
The control flows of if and switch statements are illustrated in Figure 6-1 below.
Figure 6-1. Control Flows of Conditional Statements
Control flow of switch statement
switch
case 1
case 2
case 3
default :
Control flow of if statement
if
condition
Executes
statement
that follows
if.
Executes
statement
that follows
else.
False
True
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(1) if and if ... else statements
Conditional Statements
if, if ... else
FUNCTION
An if statement has a one-way selection structure and executes the statement that follows the control expression
enclosed in parentheses if the value of the control expression is nonzero (True).
An if ... else statement has a two-way selection structure and executes the statement-1 that follows the control
expression if the value of the control expression is nonzero (True) or the statement-2 that follows else if the
value of the control expression is zero (False).
SYNTAX
if
(expression) statement
if
(expression) statement-1 else statement-2
EXAMPLE
unsigned char uc ;
void func (void){
if ( uc < 10 ){
/*111*/
}
else{
/* 222 */
}
}
EXPLANATION
In the above example, if the value of uc is less than 10 based on the control expression in the if statement, the
block "{/*111*/}" is executed. If the value is greater than 10, the block "{/*222*/}" is executed.
NOTE
When the processing after the if statement/if...else statement is not enclosed with "{ }", only the processing of a
line after the if statement/if...else statement is performed regarding it as the body.
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(2) switch statement
Conditional Statements
switch
FUNCTION
A switch statement has a multiway branching structure and passes control to one of a series of statements that
have the case labels in the switch body depending on the value of the control expression enclosed in
parentheses. If no case label that corresponds to the control expression exists, the statement that follows the
default label is executed. If no default label exists, no statement is executed.
SYNTAX
switch
(expression) statement
EXAMPLE
extern void func(void);
unsigned char mode ;
void main(void) {
switch (mode) {
case 2:
mode = 8 ;
break ;
case 4:
mode = 2 ;
break ;
case 8:
func( );
}
}
NOTE
The same value cannot be set in each case label in the switch body. Only one default label can be used in the
switch body.
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6.5 Iteration Statements
An iteration statement executes a group of statements in the loop body as long as the value of the control
expression enclosed in parentheses is True (nonzero). C has the following three types of iteration statements.
while
statement
do
statement
for
statement
The control flow of each type of iteration statement is illustrated in Figure 6-2 below.
Figure 6-2. Control Flows of Iteration Statements
while
condition
Executes
statement (s)
that follow
while.
False
True
Control flow of while loop
Loop
Control flow of do-while loop
while
condition
Executes
statement (s)
that follow
do.
Loop
True
False
Control flow of for loop
for
condition
Reevaluates
control
expression.
False
True
Loop
Executes
statement (s)
that follow
for.
Initialize
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(1) while statement
Iteration Statements
while statement
FUNCTION
A while statement executes one or more statements (the body of the while loop) several times as long as the
value of the control expression enclosed in parentheses is True (nonzero). The while statement evaluates the
control expression before executing its loop body.
SYNTAX
while
(expression) statements
EXAMPLE
int i, x ;
void main (void) {
i=1, x=0 ;
while ( i < 11 ) {
x += i ;
i++ ;
}
}
EXPLANATION
The above example finds the sum total of integers from 1 to 10 for x. The two statements enclosed in braces are
the body of this while loop. The control expression "i<11" returns 0 if the value of i becomes 11. For this reason,
the loop body is executed repeatedly as long as the value of i is less than 11 (between 1 and 10).
"while(1) {statement}" is used to endlessly perform a loop statement.
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(2) do statement
Iteration Statements
do statement
FUNCTION
A do statement executes the body of the loop as long as the control expression enclosed in parentheses is True
(nonzero). The do statement evaluates the control expression after the loop body has been executed.
SYNTAX
do
statements while (expression) ;
EXAMPLE
Int i, x ;
void main (void) {
i=1, x=0 ;
do {
x += i ;
i++ ;
} while( i<11 );
}
EXPLANATION
The above example finds the sum total of integers from 1 to 10 for x. The two statements enclosed in braces are
the body of this do ... while loop. The control expression "i<11" returns 0 if the value of i becomes 11. For this
reason, the loop body is executed repeatedly as long as the value of i is less than 11 (between 1 and 10). The
body of the loop is always performed once or more since the control expression of a do statement is evaluated
after execution.
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(3) for statement
Iteration Statements
for statement
FUNCTION
A for statement executes the body of the for loop a specified number of times as long as the value of the control
expression is nonzero (True). Of the three expressions inside the parentheses separated by semicolons, the first
expression is an initializing statement to initialize a variable to be used as a counter and is executed only once in
the beginning of the loop, the second is the control expression for testing the counter value, and the third is a
step statement executed at the end of every loop and reevaluates the variable after the execution.
SYNTAX
for (
1st-expression ; 2nd-expression ; 3rd-expression) statements
EXAMPLE
int i, x=0 ;
for( i=1 ; i<11 ; ++i )
x += i ;
EXPLANATION
The above example finds the sum total of integers from 1 to 10 for x. "x+=i" is the body of this for loop. The
control expression "i<11" returns 0 if the value of i becomes 11. For this reason, the loop body is executed
repeatedly as long as the value of i is less than 11 (between 1 and 10).
NOTE
When the processing after for statement is not enclosed with "{ }", only the processing of a line after the for
statements is regarded as the body of the loop of the for statement. The first and the third expression of a for
statement can be omitted. When the second expression is omitted, it is replaced with a constant other than 0.
The description of "for (; ;) statement" is used to endlessly perform the body of the loop.
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6.6 Branch Statements
A branch statement is used to exit from the current control flow and transfer control to elsewhere in the program.
Branch statements include the following four statements.
goto
statement
continue
statement
break
statement
return
statement
The control flow of each type of branch statement is shown in Figure 6-3.
Figure 6-3. Control Flows of Branch Statements
continue
continue
Loop
break
break
Loop
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(1) goto statement
Branch Statements
goto
FUNCTION
A goto statement causes program execution to unconditionally jump to the label name specified in the goto
statement within the current function.
SYNTAX
goto
identifier ;
EXAMPLE
do {
/*...*/
goto point ;
/*...*/
}while(/*...*/) ;
/*...*/
point: ;
EXPLANATION
In the above example, when control is passed to the goto statement, C jumps out of the current do ... while loop
processing unconditionally and transfers control to the statement next to "point".
NOTE
The label name (branch destination) to be specified in a goto statement must have been specified within the
current function that includes the goto statement. In other words, a goto can branch only within the current
function - not from one function to another.
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(2) continue statement
Branch Statements
continue
FUNCTION
A continue statement is used in the body of loops in a looping statement. continue ends one cycle of the loop
by transferring control to the end of the loop body. When a continue statement is enclosed by more than one
loop, it ends the cycle of the smallest enclosing loop.
SYNTAX
continue ;
EXAMPLE
while(/*...*/){
/*...*/
continue ;
/*....*/
contin: ;
}
EXPLANATION
In the above example, when the while loop processing by C reaches the continue statement, C unconditionally
branches to the label "contin". The label "contin" indicates the branch destination and may be omitted. The
same branching operation may be performed by using "goto contin ;" instead of continue.
NOTE
A continue statement can only be used as the body of a loop or in the body of loops.
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(3) break statement
Branch Statements
break
FUNCTION
A break statement may appear in the body of a loop and in the body of a switch statement and causes control to
be transferred to the statement next to the loop or switch statement.
SYNTAX
break ;
EXAMPLE
Int i;
unsigned char count, flag;
void main(void) {
/* ... */
for (i = 0;i < 20;i++) {
switch(count){
case 10 :
flag = 1;
break;
/* exit switch statement */
default:
func() ;
}
if (flag)
break ;
/*exit for loop */
}
}
EXPLANATION
In the above example, break statements are used so that more than required evaluations are not performed in
the body of the switch statement. If the corresponding case label is found in evaluating the switch statement,
the break statement causes C to exit from the switch statement.
NOTE
A break statement can only be used as the body of a looping or switch statement or in the loop or switch body.
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(4) return statement
Branch Statements
return
FUNCTION
A return statement exits the function that includes the return and passes controls to the function that called the
return, and calls and returns the value of the return statement expression as the value of the function call
expression. Two or more return statements may be used in a function. Using the closing brace"}" at the end of
a function produces the same result as when a return statement without expression is executed.
SYNTAX
return
expression ;
EXAMPLE
Int f(int);
void main(void) {
/*...*/
int i = 0, y = 0 ;
y = f(i) ;
/*...*/
}
int (int i) {
int x = 0 ;
/*...*/
return(x) ;
}
EXPLANATION
In the above example, when control is passed to the return statement, the function f( ) returns a value to the
function main ( ). Because the value of the variable "x" is returned as the return value, the assignment operator
causes the variable "y" to be substituted with the value of the variable "x".
NOTE
With a void type function, an expression that indicates a return value cannot be used for a return statement.
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CHAPTER 7 STRUCTURES AND UNIONS
A structure or union is a collection of member objects with different types grouped under one given name. The
member objects of a structure are allocated successively to memory space, while the member objects of a union
share the same memory.
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7.1 Structures
As mentioned earlier, a structure is a collection of member objects successively allocated to memory space.
(1) Declaration of structure and structure variable
A structure declaration list and a structure variable are declared with the keyword struct. Any "tag" name can be
given to the structure declaration list.
Subsequently, the structure variables of the same structure may be declared using this tag name.
[Declaration of structure]
struct
tag name structure declaration list variable name;
In the following example, in the first struct declaration, int type array "code", char type arrays name, addr, and
tel which have the tag name "data" are specified and no1 is declared as the structure variable. In the second
struct declaration, the structure variables no2, no3, no4, and no5 that are of the same structure as no1 are
declared.
[Example]
struct data {
int code;
char name [12];
char addr [50];
char tel [12];
} no1;
struct data no2, no3, no4, no5;
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(2) Structure declaration list
A structure declaration list specifies the structure of a structure type to be declared. Individual elements in the
structure declaration list are called members and an area is allocated for each of these members in the order of
their declaration. In the following [Example of structure declaration list], an area is allocated in the order of
variable a, array b, and two dimensional array c.
Neither an incomplete type (an array of unknown size) nor a function type can be specified as the type of each
member. Therefore, the structure itself cannot be included in the structure declaration list.
Each member can have any object type other than the above two types. A bit field that specifies each member in
bits can also be specified.
If a variable takes a binary value "0" or "1", the minimum required number of bits is specified as 1 for a bit field.
By this specification of the minimum required number of bits with the bit field, two or more members can be
stored in an integer area.
[Example of structure declaration list]
int a;
char b [7];
char c [5] [10];
[Example of bit field declaration]
struct bf_tag {
unsigned int a:2;
unsigned int b:3;
bit field
unsigned int c:1;
} bit_field;
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(3) Arrays and pointers
Structure variables may also be declared as an array or referenced using a pointer.
[Structure arrays]
An array of structures is declared in the same ways as other objects.
struct data{
char name [12];
char addr [50];
char tel [12];
};
struct data no [5];
[Structure pointers]
A pointer to a structure has the characteristics of the structure indicated by the pointer. In other words, if a
structure pointer is incremented, adding the size of the structure to the pointer points to the next structure.
In the following example, "dt_p" is a pointer to the value of "struct data" type. Here, if the pointer "dt_p" is
incremented, the pointer becomes the same value as "&no[1]".
struct data no[5];
struct data *dt_p = no;
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(4) How to refer to structure members
A structure member (or structure element) may be referenced in two ways: one by using a structure variable and
the other by using a pointer to a variable.
[Reference by using a structure variable]
The . (dot) operator is used for referring to a structure member by using a structure variable.
struct data {
char name [12];
char addr [50];
char tel [12];
} no[5] = {"NAME", "ADDR", "TEL"}; *data_ptr = no;
void main(){
char c;
c = no[0]. name[1];
}
[Reference by using a pointer to a variable]
The
-> (arrow) operator is used for referring to a structure member by using a pointer to a variable.
struct data {
char name [12];
char addr [50];
char tel [12];
} no[5] = {"NAME", "ADDR", "TEL"}, *data_ptr = no;
void main(){
char c;
data_ptr -> tel [3] = `E' ;
}
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7.2 Unions
As mentioned earlier, a union is a collection of members that share the same memory space (or overlap in
memory).
(1) Declaration of union and union variable
A union declaration list and a union variable are declared with the keyword union. Any "tag" name can be given
to the union declaration list. Subsequently, the union variables of the same union may be declared using this tag
name.
[Declaration of union]
union
tag name {union declaration list} variable name;
In the following example, in the first union declaration, char type arrays "name", "addr", and "tel" that have the
tag name "data" are specified and "no1" is declared as the union variable. In the second union declaration, the
union variables "no2, no3, no4, and no5", which are of the same union as "no1", are declared.
union data {
char name [12];
char addr [50];
char tel [12];
} no1;
union data no2, no3, no4, no5;
(2) Union declaration list
A union declaration list specifies the structure of a union type to be declared. Individual elements in the union
declaration list are called members and an area is allocated for each of these members in the order of their
declaration. In the following [Example of union declaration list], an area is allocated to `c', which becomes the
largest area of the members. The other members are not allocated new areas but use the same area.
Neither an incomplete type (an array of unknown size) nor a function type can be specified as the type of each
member same as the union declaration list.
Each member can have any object type other than the above two types.
[Union declaration list]
int a;
char b [7];
char c [5] [10];
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(3) Union arrays and pointers
Union variables may also be declared as an array or referenced using a pointer (in much the same way as
structure arrays and pointers).
[Union arrays]
An array of unions is declared in the same ways as other objects.
union data {
char name [12];
char addr [50];
char tel [12];
};
union data no [5];
[Union pointers]
A pointer to a union has the characteristics of the union indicated by the pointer. In other words, if a union
pointer is incremented, adding the size of the union to the pointer points to the next union.
In the following example, "dt_p" is a pointer to the value of "union data" type.
union data no[5];
union data *dt_p = no;
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(4) How to refer to union members
A union member (or union element) may be referenced in two ways: one by using a union variable and the other
by using a pointer to a variable.
[Reference by using a union variable]
The . (dot) operator is used for referring to a union member by using a union variable.
union data {
char name [12];
char addr [50];
char tel [12];
} no[5] = {"NAME", "ADDR", "TEL"};
void main (void) {
no[0].addr[10] = `B' ;
:
}
[Reference by using a pointer to a variable]
The
-> (arrow) operator is used for referring to a union member by using a pointer to a variable.
union data {
char name [12];
char addr [50];
char tel [12];
} *data_ptr ;
void main(void) {
data_ptr -> name[1] = `N' ;
:
}
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CHAPTER 8 EXTERNAL DEFINITIONS
In a program, lists of external declarations come after the preprocessing. These declarations are referred to as
"external declarations" because they appear outside a function and have effective file ranges.
A declaration to give a name to external objects by identifiers or a declaration to secure storage for a function is
called an external definition. If an identifier declared with external linkage is used in an expression (except the
operand part of the sizeof operator), one external definition for the identifier must exist somewhere in the entire
program.
The syntax of external definitions is given below.
#define
TRUE
1
#define
FALSE
0
#define
SIZE
200
void printf (char*, int);
void putchar (char c);
char mark[SIZE+1];
External object declaration
main()
{
int i, prime, k, count;
count = 0;
for ( i = 0 ; i <= SIZE ; i++)
mark [i] = TRUE;
for ( i = 0 ; i <= SIZE ; i++){
if (mark[i]) {
prime = i + i + 3;
printf ("%d ",prime);
count++;
if ( (count%8) = = 0) putchar(`\n');
for ( k = i + prime ; k <= SIZE ; K += prime )
mark[k] = FALSE;
}
}
printf("Total %d\n", count);
loop1:
goto loop1;
}
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8.1 Function Definition
A function definition is an external definition that begins with a declaration of the function. If the storage class
specifier is omitted from the declaration, extern is assumed to have been defined. An external function definition
means that the defined function may be referenced from other files. For example, in a program consisting of two or
more files, if a function in another file is to be referenced, this function must be defined externally.
The storage class specifier of an external function is extern or static. If a function is declared as extern, the
function can be referenced from another file. If declared as static, it cannot be referenced from another file.
In the following example, the storage class specifier is "extern" and the type specifier is "int". These two are
default values and thus may be omitted from specification. The function declarator is "max(int a, int b)" and the body
of the function is "{return a>b?a:b;)".
[Example of function definition]
extern int max(int a, int b)
{
return a>b?a :b ;
}
Because this function definition specifies a parameter type in the function declaration, the type of argument is
forcibly converted by the compiler. This type conversion can be described by using the form of an identifier list for
the parameters. An example of this identifier list is shown below.
extern int max(a, b)
int a, b;
{
return a>b?a:b;
}
The address of a function may be passed as an argument to the function call. By using the function name in the
expression, a pointer to the function can be generated.
int f(void);
void main( ){
:
g(f);
}
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In the above example, the function g is passed to the function f by a pointer that points to the function f. The
function g must be defined in either of the following two ways.
void g (int(*funcp)(void))
{
(*funcp) (); /*
or funcp();*/
}
or
void g (int func(void))
{
func(); /*
or (*func)();*/
}
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8.2 External Object Definitions
An external object definition refers to the declaration of an identifier for an object that has file scope or an
initializer. If the declaration of an identifier for an object that has file scope has no initializer without storage class
specification or has static storage class, the object definition is considered to be temporary, because it becomes a
declaration that has file scope with initializer 0.
Examples of external object definitions are shown below.
[Example of external object definition]
int i1 = 1 ;
........................
Definition with external linkage
static int i2 = 2 ;
.......
Definition with internal linkage
extern int i3 = 3 ;
.......
Definition with external linkage
int i4 ;
..............................
Temporary definition with external linkage
static int i5 ;
...............
Temporary definition with internal linkage
int i1 ;
..............................
Valid temporary definition which refers to previous declaration
int i2 ;
..............................
Violation of linkage rule
int i3 ;
..............................
Valid temporary definition which refers to previous declaration
int i4 ;
..............................
Valid temporary definition which refers to previous declaration
int i5 ;
..............................
Violation of linkage rule
extern int i1 ;
...............
Reference to previous declaration which has external linkage
extern int i2 ;
...............
Reference to previous declaration which has internal linkage
extern int i3 ;
...............
Reference to previous declaration which has external linkage
extern int i4 ;
...............
Reference to previous declaration which has external linkage
extern int i5 ;
...............
Reference to previous declaration which has internal linkage
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CHAPTER 9 PREPROCESSING DIRECTIVES (COMPILER DIRECTIVES)
A preprocessing directive is a string of preprocessing tokens between the # preprocessing token and the line feed
character.
Blank characters that can be used between preprocessing token strings are only spaces and horizontal tabs.
A preprocessing directive specifies the processing performed before compiling a source file. Preprocessing
directives include operations such as processing or skipping a part of a source file depending on the conditions,
obtaining additional code from other source files, and replacing the original source code with other text as in macro
expansion. The preprocessing directives are described below.
9.1 Conditional Translation Directives
Conditional translation skips part of a source file according to the value of a constant expression. If the value of
the constant expression specified by a conditional translation directive is 0, the statements that follow the directive
are not translated (compiled). The sizeof operator, cast operator, or an enumerated type constant cannot be used in
the constant expression of any conditional translation directive.
Conditional translation directives include #if, #elif, #ifdef, #ifndef, #else, and #endif.
In preprocessing directives, the following unary expressions called defined expressions may be used.
defined
identifier
or
defined
(identifier)
The unary expression returns 1 if the identifier has been defined with the #define preprocessing directive and 0 if
the identifier has never been defined or its definition has been canceled.
[Example]
In this example, the unary expression returns 1 and compiles between #if and #endif because SYM has been
defined (for the explanation of #if through #endif, refer to the explanations on the following pages).
#define SYM 0
#if defined SYM
:
#endif
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(1) #if directive
Conditional Translation Directives
#if
FUNCTION
The #if directive tells the translation phase of C to skip (discard) a section of source code if the value of the
constant expression is 0.
SYNTAX
#if
constant expression line feed
group
EXAMPLE
#if FLAG == 0
:
#endif
EXPLANATION
In the above example, the constant expression "FLAG == 0" is evaluated to determine whether a set of
statements (i.e., source code) between #if and #endif is to be used in the translation phase. If the value of
"FLAG" is nonzero, the source code between #if and #endif will be discarded. If the value is zero, the source
code between #if and #endif will be translated.
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(2) #elif directive
Conditional Translation Directives
#elif
FUNCTION
The #elif directive normally follows the #if directive. If the value of the constant expression of the #if directive is
0, the constant expression of the #elif directive is evaluated. If the constant expression of the #elif directive is 0,
the translation phase of C will skip (discard) the statements (a section of source code) between #elif and #endif.
SYNTAX
#elif
constant-expression line feed
group
EXAMPLE
#if FLAG == 0
:
#elif FLAG != 0
:
#endif
EXPLANATION
In the above example, the constant expression "FLAG= =0" or "FLAG!=0" is evaluated to determine whether a
set of statements that follow #if and another set of statements that follow #elif is to be used in the translation
phase. If the value of "FLAG" is zero, the source code between #if and #elif will be translated. If the value is
nonzero, the source code between #elif and #endif will be translated.
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(3) #ifdef directive
Conditional Translation Directives
#ifdef
FUNCTION
The #ifdef directive is equivalent to:
#if defined (identifier)
If the identifier has been defined with the #define directive, the statements between #ifdef and #endif will be
translated. If the identifier has never been defined or its definition has been canceled, the translation phase will
skip the source code between #ifdef and #endif.
SYNTAX
#ifdef
identifier line feed
group
EXAMPLE
#define ON
#ifdef ON
:
#endif
EXPLANATION
In the above example, the identifier "ON" has been defined with the #define directive. Thus, the source code
between #ifdef and #endif will be translated. If the identifier "ON" has never been defined, the source code
between #ifdef and #endif will be discarded.
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(4) #ifndef directive
Conditional Translation Directives
#ifndef
FUNCTION
The #ifndef directive is equivalent to:
#if !defined (identifier)
If the identifier has never been defined with the #define directive, the source code between #ifndef and #endif
will not be translated.
SYNTAX
#ifndef
identifier line feed
group
EXAMPLE
#define ON
#ifndef ON
:
#endif
EXPLANATION
In the above example, the identifier "ON" has been defined with the #define directive. Thus, the source code
between #ifndef and #endif will be discarded in the translation phase. If the identifier "ON" has never been
defined, the source code between #ifndef and #endif will be translated.
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(5) #else directive
Conditional Translation Directives
#else
FUNCTION
The #else directive tells the translation phase of C to discard a section of source code that follows #else if the
identifier of the preceding conditional translation directive is nonzero.
The #if, #elif, #ifdef, or #ifndef directive may precede the #else directive.
SYNTAX
#else
line feed
group
EXAMPLE
#define ON
#ifdef ON
:
#else
:
#endif
EXPLANATION
In the above example, the identifier "ON" has been defined with the #define directive. Thus, the source code
between #ifndef and #endif will be translated. If the identifier "ON" has never been defined, the source code
between #else and #endif will be translated.
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(6) #endif directive
Conditional Translation Directives
#endif
FUNCTION
The #endif directive indicates the end of a #ifdef block.
SYNTAX
#endif
line feed
EXAMPLE
#define ON
#ifdef ON
:
:
#endif
EXPLANATION
In the above example, #endif indicates the end of the #ifdef block (effective range of #ifdef directive).
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9.2 Source File Inclusion Directive
The preprocessing directive #include searches for a specified header file and replaces #include by the entire
contents of the specified file. The #include directive may take one of the following three forms for inclusion of other
source files.
#include <file-name>
#include "file-name"
#include preprocessing token string
An #include directive may appear in the source obtained by #include. In this compiler, however, there are
restrictions for #include directive nesting. For the restrictions, refer to Table 1-1 Maximum Performance
Characteristics of This C Compiler.
Remark
Preprocessing token string: Character string defined by the #define directive
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(1) #include < >
Source File Inclusion Directive
#include< >
FUNCTION
If the directive form is #include < >, the C compiler searches the directory specified by the -i compiler option, the
directory specified by the INC78K environment variable, and the directory \NECTools32\INC78K4 registered in
the registry for the header file specified in angle brackets and replaces the #include directive line with the entire
contents of the specified file.
SYNTAX
#include
<file-name> line feed
EXAMPLE
#include <stdio.h>
EXPLANATION
In the above example, the C compiler searches the directory specified by the INC78K environment variable and
the directory \NECTools32\INC78K4 registered in the registry for the file stdio.h and replaces the directive line
#include<stdio.h> with the entire contents of the specified file stdio.h.
Caution
The above directories differ depending on the installation method.
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(2) #include " "
Source File Inclusion Directive
#include " "
FUNCTION
If the directive form is #include " ", the current working directory is first searched for the header file specified in
double quotes. If it is not found, the directory specified by the -i compiler option, the directory specified by the
INC78K environment variable, and the directory \NECTools32\INC78K4 registered in the registry are searched.
The compiler then replaces the #include directive line with the entire contents of the specified file.
SYNTAX
#include
"file-name" line feed
EXAMPLE
#include "myprog. h"
EXPLANATION
In the above example, the C compiler searches the current working directory, the directory specified by the
INC78K environment variable, and the directory \NECTools32\INC78K4 registered in the registry for the file
myprog.h specified in double quotes and replaces the directive line #include "myprog.h" with the entire
contents of the specified file myprog.h.
Caution
The above directories differ depending on the installation method.
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(3) #include preprocessing token string
Source File Inclusion Directive
#include token string
FUNCTION
If the directive form is #include preprocessing token string, the header file to be searched is specified by macro
replacement and the #include directive line is replaced by the entire contents of the specified file.
SYNTAX
#include
preprocessing token string line feed
EXAMPLE
#define INCFILE "myprog.h"
#include INCFILE
EXPLANATION
When including source files using the directive form "#include preprocessing token string line feed", the
specified "preprocessing token string" must be substituted with <file-name> or "file name" by macro replacement.
If the token string is replaced by <file-name>, the C compiler searches the directory specified by the -i compiler
option, the directory specified by the INC78K environment variable, and the directory \NECTools32\INC78K4
registered in the registry for the specified file. If the token string is replaced by "file name", the current working
directory is searched. If the specified file is not found, the directory specified by the -i compiler option, the
directory specified by the INC78K environment variable, and the directory \NECTools32\INC78K4 registered in
the registry are searched.
Caution
The above directories differ depending on the installation method.
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9.3 Macro Replacement Directives
The macro replacement directives #define and #undef are used to replace the character string specified by
"identifier" with "substitution list" and to end the scope of the identifier given by the #define, respectively. The
#define directive has two forms: Object format and Function format.
Object format
#define identifier replacement list line feed
Function format
#define
identifier (
identifier-list ) replacement-list line feed
(1) Actual argument replacement
Actual argument replacement is executed after the arguments in the function-form macro call are identified. If
the # or ## preprocessing token is not prefixed to a parameter in the replacement list or if the ## preprocessing
token does not follow any such parameter, all macros in the list will be expanded before replacement with the
corresponding macro arguments.
(2) # operator
The # preprocessing token replaces the corresponding macro argument with a char string processing token. In
other words, if this preprocessing token is prefixed to a parameter in the replacement list, the corresponding
macro argument will be translated into a character or character string.
(3) ## operator
The ## preprocessing token concatenates the two tokens on either side of the ## symbol into one token. This
concatenation will take place before the next macro expansion and the ## preprocessing token will be deleted
after the concatenation. The token generated from this concatenation will undergo macro expansion if it has a
macro name.
[Example of ## operation]
The above macro replacement directive will be expanded as follows.
printf("x" "1""=%d, x" "2" "=%s", x1, x2);
The concatenated char string will look like this.
printf ("x1=%d, x2=%s", x1, x2);
#include <stdio.h>
#define debug(s, t)
printf("x"#s"= %d, x"#t"=%s", x##s, x##t);
void main() {
int x1, x2;
debug (1, 2);
}
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(4) Re-scanning and further replacement
The preprocessing token string resulting from replacement of macro parameters in the list will be scanned again,
together with all remaining preprocessing tokens in the source file. Macro names currently being replaced (not
including the remaining preprocessing tokens in the source file) will not be replaced even if they are found during
scanning of the replacement list.
(5) Scope of macro definition
A macro definition (#define directive) continues macro replacement until it encounters the corresponding #undef
directive.
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(6) #define directive
Macro Replacement Directives
#define
FUNCTION
The #define directive in its simplest form replaces the specified identifier (manifest) with a given replacement list
(any character sequence that does not contain a line feed) whenever the same identifier appears in the source
code after the definition by this directive.
SYNTAX
#define
identifier replacement list line feed
EXAMPLE
#define PAI 3.1415
EXPLANATION
In the above example, the identifier "PAI" will be replaced with "3.1415" whenever it appears in the source code
after the definition by this directive.
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(7) #define( ) directive
Macro Replacement Directives
#define ( )
FUNCTION
The function-form #define directive which has the form:
#define name (name, ..., name) replacement list
replaces the identifier specified in the function format with a given replacement list (any character sequence that
does not contain a line feed). No white space is allowed between the first name and the opening parenthesis "(".
This list of names (identifier list) may be empty. Because this form of the directive defines a macro, the macro
call will be replaced with the parameters of the macro inside the parentheses.
SYNTAX
#define
identifier (
identifier list ) replacement-list line feed
EXAMPLE
#define F(n) (n*n)
void main() {
int i;
i=F(2)
}
EXPLANATION
In the above example, #define directive will replace "F(2)" with "(2*2)" and thus the value of i will become 4. For
the sake of safety, be sure to enclose the replacement list in parentheses, because unlike a function definition,
this function-form macro is merely to replace a sequence of characters.
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(8) #undef directive
Macro Replacement Directives
#undef
FUNCTION
The #undef directive undefines the given identifier. In other words, this directive ends the scope of the identifier
that has been set by the corresponding #define directive.
SYNTAX
#undef
identifier line feed
EXAMPLE
#define F(n) (n*n)
:
#undef F
EXPLANATION
In the above example, #undef directive will invalidate the identifier "F" previously specified by "#define F(n)
(n*n)".
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9.4 Line Control Directive
The preprocessing directive for line control #line replaces the line number to be used by the C compiler in
translation with the number specified in this directive. If a string (character string) is given in addition to the number,
the directive also replaces the source file name the C compiler has with the specified string.
(1) To change the line number
To change the line number, the specification is made as follows. 0 and numbers larger than 32767 cannot be
specified.
#line
numeric-string line feed
[Example]
#line 10
(2) To change the line number and the file name
To change the line number and file name, the specification is made as follows.
#line
numeric-string "character string" line feed
[Example]
#line 10 "file1.c"
(3) To change using preprocessing token string
In addition to the specifications above, the following specification can also be made. In this case, the specified
preprocessing token string must be either one of the above two examples after all the replacement.
#line
preprocessing-token-string line feed
[Example]
#define LINE_NUM
100
#line LINE_NUM
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9.5 #error Preprocessing Directive
The #error preprocessing directive is a directive that outputs a message including the specified preprocessing
tokens and incompletely terminates compileation. This preprocessing directive is used to terminate compilation.
This preprocessing directive is specified as follows.
#error
"preprocessing-token-string" line feed
[Example]
In this example, the macro name _ _K4 _ _, which indicates the device series of this compiler, is used. If the
device is the 78K/IV Series, the program between #if and #else is compiled. In the other cases, the program
between #else and #endif is compiled, but compilation will be terminated with an error message "not for 78K4"
output by the #error directive.
#if _ _K4_ _
:
#else
#error "not for 78K4"
:
#endif
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9.6 #pragma Directives
#pragma directives are directives to instruct the compiler to operate using the compiler definition method. In this
compiler, there are several #pragma directives to generate codes for the 78K/IV Series (for details of #pragma
directives, refer to CHAPTER 11 EXTENDED FUNCTIONS).
[Example]
In this example, the #pragma NOP directive enables the description to directly output a NOP instruction in the C
source.
#pragma NOP
9.7 Null Directives
Source lines that contain only the # character and white space are called null directives. Null directives are simply
discarded during preprocessing. In other words, these directives have no effect on the compiler. The syntax of null
directives is given below.
#
line feed
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9.8 Compiler-Defined Macro Names
In this C compiler, the following macro names have been defined.
_ _LINE_ _
Line number of the current source line (decimal constant)
_ _FILE_ _
Source file name (string literal)
_ _DATE_ _
Date the source file was compiled (string literal in the form of "Mmm dd yyyy")
_ _TIME_ _
Time of day the source file was compiled (string literal in the form of "hh:mm:ss")
_ _STDC_ _
Decimal constant "1" that indicates the compliance with ANSI
Note
specification
Note ANSI is the acronym for American National Standards Institute
A #define or #undef preprocessing directive must not be applied to these macro name and defined identifiers.
All the macro names of the compiler definition start with an underscore followed by an uppercase character or a
second underscore.
In addition to the above macro names, macro names indicating the series name of devices according to the
device subject to applied product development and macro names indicating device names are provided. To output
the object code for the target device, these macro names must be specified by the option at compilation or by the
processor type in the C source.
Macro name indicating the series name of devices
`_ _K4 _ _'
Macro name indicating the device name
`_ _' is added before the device type name and `_' is added after the device type name.
Describe letters in uppercase
(Example)
_ _4026_ _ _4038Y_
Remark
The device type names are the same as those specified by the -C option. For the device type names,
refer to the reference materials related to device files.
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This C compiler has a macro name indicating the memory model or location.
Macro name indicating memory model
When small model is specified
#define _ _K4_SMALL_ _
1
When medium model is specified
#define _ _K4_MEDIUM_ _
1
When large model is specified
#define _ _K4_LARGE_ _
1
Macro name indicating location
Location 0
#define _ _K4LOC0_ _
1
Location 15
#define _ _K4LOC15_ _
1
The device type for compilation is specified by adding the following to the command line
`-c device type name'
Example
cc78k4 -c4038Y prime.c
It is possible to avoid specifying the device type at compilation by specifying it at the start of the C source
program.
`#pragma PC (device type)'
Example
#pragma PC (4038Y)
:
However, the following can be described before `#pragma PC (device type)'
Comment statement
Preprocessing directives that do not generate definition/reference of variables nor functions.
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CHAPTER 10 LIBRARY FUNCTIONS
C has no instructions to transfer (input or output) data to and from external sources (peripheral devices and
equipment). This is because of the C language designer's intent to hold the functions of C to a minimum. However,
for actually developing a system, I/O operations are requisite. Thus, C is provided with library functions to perform
I/O operations.
This C compiler is provided with library functions such as I/O, character/memory manipulation, program control,
and mathematical functions. This chapter describes the library functions provided in this compiler.
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10.1 Interface Between Functions
To use a library function, the function must be called. Calling a library function is carried out by a call instruction.
The arguments and return value of a function are passed via a stack and a register, respectively. However, when the
old function interface supporting option (-ZO) is not specified, the first argument is, if possible, also passed via a
register.
For the -ZO option, refer to CHAPTER 5 COMPILER OPTION in the CC78K4 C Compiler Operation User's
Manual (U15557E).
10.1.1 Arguments
Placing or removing arguments on or from the stack is performed by the caller (calling function). The callee
(called function) only references the argument values. However, when the argument is passed via a register, the
callee directly refers to the register and copies the value of the argument to another register, if necessary. Also,
when specifying the function call interface automatic pascal function option -ZR, removal of arguments from the stack
is performed by the called side if the argument is passed by the stack.
Arguments are placed on the stack one by one in descending order from bottom to top if the argument is passed
via the stack.
The minimum unit of data that can be stacked is 16 bits. A data type larger than 16 bits is stacked in units of 16
bits one by one from its MSB. An 8-bit type data is extended to a 16-bit type data for stacking.
When it is a large model and the argument is the address value or when it is a medium model and the argument is
the address value of the function, the argument is stacked in 3-byte units.
The following shows the list of the passing of the first argument. The second and subsequent arguments are
passed via a stack.
The function interface (passing of argument and storing of return value) of the standard library is the same as that
of normal function.
Table 10-1. List of Passing First Argument
Type of First Argument
Passing Method (Without -ZO Specification)
Passing Method
(with -ZO Specification)
1-byte, 2-byte integer
AX
Passed via a stack
3-byte integer
WHL, small model: stack passing
Passed via a stack
4-byte integer
AX, RP2
Passed via a stack
Floating-point number
(float type)
AX, RP2
Passed via a stack
Floating-point number
(double type)
AX, RP2
Passed via a stack
Other
Passed via a stack
Passed via a stack
Remark
Of the types shown above, 1- to 4-byte integers include structures and unions.
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10.1.2 Return values
The return value of a function is stored in units of 16 bits starting from its LSB in the direction from the register BC
to the register RPZ. When returning a structure, the first address of the structure is stored in the register BC. When
returning a pointer, the first address of the structure is stored in the register BC.
The following shows the list of storing the return value. The method of storing return values is the same as that of
normal functions.
Table 10-2. List of Storing Return Value
Return Value Type
Small Model
Medium Model
Large Model
1 bit
CY
CY
CY
1-byte, 2-byte integers
BC
BC
BC
4-byte integers
BC (lower), RP2 (higher)
BC (lower), RP2 (higher)
BC (lower), RP2 (higher)
Floating-point number
(float type)
BC (lower), RP2 (higher)
BC (lower), RP2 (higher)
BC (lower), RP2 (higher)
Floating-point number
(double type)
BC (lower), RP2 (higher)
BC (lower), RP2 (higher)
BC (lower), RP2 (higher)
Structure
Copies the structure to return
to the area specific to the
function and stores the
address in BC
Copies the structure to return
to the area specific to the
function and stores the
address in BC
Copies the structure to return
to the area specific to the
function and stores the
address in TDE
Pointer
BC
BC (function pointer)
WHL (function pointer)
TDE
10.1.3 Saving registers to be used by individual libraries
Each library that uses RP3, RG4 (VVP) and RG5 (UUP) saves the registers it uses to a stack.
Each library that uses a saddr area saves the saddr area it uses to a stack. A stack area is used as a work area
for each library.
(1) When -ZR option is not specified
The procedure of passing arguments and return values is shown below. An example of the small model is shown
below.
Called function "long func (int a, long b, char *c) ;"
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<1> Placing arguments on the stack (by the caller)
The higher 16 bits of arguments "c" and "b" and lower 16 bits of argument "b" are placed on the stack in the
order named. a is passed via the AX register.
<2> Calling func by call instruction (by the caller)
The return address is placed on the stack next to the lower 16 bits of argument "b" and control is
transferred to the function func.
<3> Saving registers to be used within the function (by the callee)
If register RP3 is to be used, RP3 is placed on the stack.
<4> Placing the first argument passed via the register on the stack (by the callee)
<5> Processing func and storing the return value in registers (by the callee)
The lower 16 bits of the return value "long" are stored in BC and the higher 16 bits of the return value, are
stored are stored in RP2.
<6> Restoring the stored first argument (by the callee)
<7> Restoring the saved registers (by the callee)
<8> Returning control to the caller with ret instruction (by the callee)
<9> Removing arguments from the stack (by the caller)
The number of bytes (in units of 2 bytes) of the arguments is added to the stack pointer. In the example
shown in Figure 10-1, 6 is added.
Figure 10-1. Stack Area When Function Is Called (No ZR Specified)
Stack pointer after <6>
Stack pointer after <7>
Stack pointer after <8>
Stack pointer after <9>
Stack pointer after <4>
Stack pointer after <3>
Stack pointer after <2>
Stack pointer after <1>
Stack pointer before
stacking arguments
BC
RP2
Lower 16 bits
Higher 16 bits
Return value in <5> is stored
a
RP3
Return address
Lower 16 bits of b
Higher 16 bits of b
c
High address
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(2) When -ZR option is specified
The following example shows the procedure of passing arguments and return values when the -ZR option is
specified.
Called function "long func (int a, long b, char *c);"
<1> Place arguments on the stack (by the caller)
The higher 16 bits of arguments "c" and "b" and the lower 16 bits of argument "b" are placed on the stack in
the order named. a is passed via the AX register.
<2> Call func by call instruction (by the caller).
The return address is placed on the stack next to the lower 16 bits of argument "b" and control is
transferred to the function func.
<3> Save the registers used in the functions (by the caller).
<4> Perform processing of the function func, and store return values in the register (by the callee).
Store the lower 16 bits of the return value (long) in BC and the higher 16 bits in RP2.
<5> Restore the saved registers (by the callee).
<6> Save the return address in the register (by the callee).
Save the return address in the WHL register.
<7> The caller restores the placed arguments (by the callee).
<8> Return control to the function on the caller in the branch instruction (by the callee) at the value saved in the
register in <6>.
Return control to the function on the caller in the BR WHL instruction (by the callee).
Figure 10-2. Stack Area When Function Is Called (ZR Specified)
Stack pointer after <5>
Stack pointer after <6>
Stack pointer after <7>
Stack pointer after <2>
Stack pointer after <1>
Stack pointer after <3>
Stack pointer before
stacking arguments
BC
RP2
Lower 16 bits
Higher 16 bits
Return value in <4> is stored
RP3
Return address
Lower 16 bits of b
Higher 16 bits of b
c
High address
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10.2 Headers
This C compiler has 13 headers (or header files). Each header defines or declares standard library functions,
data type names, and macro names.
These 13 headers are as shown below.
ctype.h
setjmp.h
stdarg.h
stdio.h
stdlib.h
string.h
error.h
errno.h
limits.h
stddef.h
math.h
float.h
assert.h
(1) ctype.h
This header is used to define character and string functions. In this standard header, the following library
functions have been defined.
However, when the compiler option -ZA (the option that disables the functions not complying with ANSI
specifications and enables a part of the functions of ANSI specifications) is specified, _toupper and _tolower
are not defined. Instead, tolow and toup are defined. When -ZA is not specified, tolow and toup are not
defined.
Isalnum
isalpha
iscntrl
isdigit
isgraph
islower
isprint
ispunct
isspace
isupper
isxdigit
tolower
toupper
isascii
toascii
_toupper
_tolower
tolow
toup
(2) setjmp.h
This header is used to define program control functions. In this standard header, the setjmp and longjmp
functions have been defined.
In the header setjmp.h, the following object has been defined.
[Declaration of char array type jmp_buf with an array size of greater than 30]
typedef char jmp_buf[30]
(3) stdarg.h
This header used to define special functions. In this standard header, the following four library functions have
been defined.
When the -ZO option (old function interface supporting option) is not specified, the va_start function cannot be
specified for the first argument because the first argument is passed via the register.
Use the macro in the following manner when the -ZO option is not specified.
Use the va_starttop macro when specifying the first argument.
Use the va_start macro when specifying the second argument.
va_start
va_starttop va_arg
va_end
In the header stdarg.h the following object has been declared.
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[Declaration of pointer type va_list to char]
typedef char *va_list;
(4) stdio.h
This header is used to define I/O functions. In this standard header, the following functions have been defined.
sprintf
sscanf
printf
scanf
vprintf
vsprintf
getchar
gets
putchar
puts
The following macro names are declared.
#define
EOF
(1)
#define
NULL
(void *)0
(5) stdlib.h
This header is used to define character and string functions, memory functions, program control functions,
mathematical functions, and special functions. In this standard header, the following library functions have been
defined.
However, when the compiler option -ZA (the option that disables the functions not complying with ANSI
specifications and enables a part of the functions of ANSI specifications) is specified, brk, sbrk, itoa, ltoa, and
ultoa are not defined. Instead, strbrk, strsbrk, stritoa, strltoa, and strultoa are defined. When -ZA is not
specified, strbrk, strsbrk, stritoa, strltoa, and strultoa are not defined.
atoi atol strtol strtoul
calloc free
malloc
realloc abort
atexit
exit
abs
div
labs
ldiv
brk
sbrk
atof
strtod
itoa
ltoa
ultoa rand srand
bsearch
qsort
strbrk strsbrk stritoa strltoa strultoa
In the header stdlib.h the following objects have been defined.
[Declaration of structure type "div_t" which has int type members "quot" and "rem"]
typedef struct {
int quot ;
int rem ;
} div_t ;
[Declaration of structure type ldiv_t which has long int type members quot and rem]
typedef struct {
long int quot ;
long int rem ;
} ldiv_t ;
[Definition of macro name RAND_MAX]
#define RAND_MAX 32767
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[Declaration of macro name]
define EXIT_SUCCESS
0
define EXIT_FAILURE
1
(6) string.h
This header is used to define character and string functions, memory functions, and special functions. In this
standard header, the following library functions have been defined.
Memcpy memmove strcpy stmcpy strcat strncat memcmp
Strcmp strncmp memchr strchr strcspn strpbrk strrchr
Strspn strstr strtok memset strerror strlen strcoll strxfrm
(7) error.h
error.h includes errno.h.
(8) errno.h
In this standard header, the following objects have been defined.
[Definitions of macro names "EDOM", "ERANGE", and "ENOMEM"]
#define EDOM
1
#define ERANGE
2
#define ENOMEM
3
[Declaration of volatile int type external variable errno]
extern volatile int errno ;
(9) limits.h
In this standard header, the following macro names have been defined.
#define CHAR_BIT
8
#define CHAR_MAX
+127
#define CHAR_MIN
128
#define INT_MAX
+32767
#define INT_MIN
32768
#define LONG_MAX
+2147483647
#define LONG_MIN
2147483648
#define SCHAR_MAX
+127
#define SCHAR_MIN
128
#define SHRT_MAX
+32767
#define SHRT_MIN
32768
#define UCHAR_MAX
255U
#define UINT_MAX
65535U
#define ULONG_MAX
4294967295U
#define USHRT_MAX
65535U
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However, when the -QU option, which regards unqualified char as unsigned char, is specified, CHAR_MAX and
CHAR_MIN are declared by the macro_CHAR_UNSIGNED_ _ declared by the compiler as follows.
#define CHAR_MAX
(255U)
#define CHAR_MIN
(0)
(10) stddef.h
In this standard header, the following objects have been declared and defined.
[Declaration of int type ptrdiff_t]
typedef int ptrdiff_t;
[Declaration of unsigned int type size_t]
typedef unsigned int size_t;
[Definition of macro name NULL]
#define NULL (void*)0
[Definition of macro name offsetof]
#define offsetof (type, member) ((size_t)&(((type*)0) -> member))
offsetof (type, member specifier)
offsetof is expanded to a general integer constant expression with the type size_t, and the value is an offset
value in byte units from the start of the structure (that is specified by the type) to the structure member (that is
specified by the member specifier).
The member specifier must be the one that the result of evaluation of the expression & (t. member specifier)
becomes an address constant when static type t; is declared. When the specified member is a bit field, the
operation will not be guaranteed.
(11) math.h
math.h defines the following functions.
acos
asin
atan
atan2
cos
sin
tan
cosh
sinh
tqnh
exp
frexp
ldexp
log
log10
modif
pow
sqrt
ceil
fabs
floor
fmod
acosf
asinf
atanf
atan21 cost
sinf
tanf
coshf
sinhf
tanhf
expf
frexpf
ldexpf logf
log10f modff
powf
sqrtf
ceilf
fabsf
floorf fmodf
matherr
The following objects are defined.
[Definition of macro name HUGE_VAL]
#define HUGE_VAL _HUGE
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(12) float.h
float.h defines the following objects.
When the size of a double type is 32 bits, the macros to be defined are sorted by the macro
_ _DOUBLE_IS_32BITS_ _ declared by the compiler.
#ifndef _FLOAT_H
#define FLT_ROUNDS
1
#define FLT_RADIX
2
#ifdef _ _DOUBLE_IS_32BITS_ _
#define FLT_MANT_DIG
24
#define DBL_MANT_DIG
24
#define LDBL_MANT_DIG
24
#define FLT_DIG
6
#define DBL_DIG
6
#define LDBL_DIG
6
#define FLT_MIN_EXP
125
#define DBL_MIN_EXP
125
#define LDBL_MIN_EXP
125
#define FLT_MIN_10_EXP
37
#define DBL_MIN_10_EXP
37
#define LDBL_MIN_10_EXP
37
#define FLT_MAX_EXP
+128
#define DBL_MAX_EXP
+128
#define LDBL_MAX_EXP
+128
#define FLT=MAX=10=EXP
+38
#define DBL_MAX_10_EXP
+38
#define LDBL_MAX_10_EXP
+38
#define FLT_MAX
3.40282347E+38F
#define DBL_MAX
3.40282347E+38F
#define LDBL_MAX
3.40282347E+38F
#define FLT_EPSILON
1.19209290E07F
#define DBL_EPSILON
1.19209290E07F
#define LDBL_EPSILON
1.19209290E07F
#define FLT_MIN
1.1749435E38F
#define DBL_MIN
1.17549435E38F
#define LDBL_MIN
1.17549435E38F
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#else
/* _ _DOUBLE_IS_32BITS_ _ */
#define FLT_MANT_DIG
24
#define DBL_MANT_DIG
53
#define LDBL_MANT_DIG
53
#define FLT_DIG
6
#define DBL_DIG
15
#define LDBL_DIG
15
#define FLT_MIN_EXP
125
#define DBL_MIN_EXP
1021
#define LDBL_MIN_EXP
1021
#define FLT_MIN_10_EXP
37
#define DBL_MIN_10_EXP
307
#define LDBL_MIN_10_EXP
307
#define FLT_MAX_EXP
+128
#define DBL_MAX_EXP
+1024
#define LDBL_MAX_EXP
+1024
#define FLT_MAX_10_EXP
+38
#define DBL_MAX_10_EXP
+308
#define LDBL_MAX_10_EXP
+308
#define FLT_MAX
3.40282347E+38F
#define DBL_MAX
1.7976931348623157E+308
#define LDBL_MAX
1.7976931348623157E+308
#define FLT_EPSILON
1.19209290E-07F
#define DBL_EPSILON
2.2204460492503131E-016
#define LDBL_EPSILON
2.2204460492503131E-016
#define FLT_MIN
1.17549435E-38F
#define DBL_MIN
2.225073858507201E-308
#define LDBL_MIN
2.225073858507201E-308
#endif
/* _ _DOUBLE_IS_32BITS_ _ */
#define _FLOAT_H
#endif
/* !_FLOAT_H */
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(13) assert.h
assert.h defines the following objects.
#ifdef
NDEBUG
#define assert (p)
((void)0)
#else
extern int _ _assertfail (char*_ _msg, char*_ _cond, char*_ _file, int_ _line);
#define assert (p)
((p) ? (void) 0 : (void)_ _assertfail
"Assertion failed: %s, file %s, line %d\n", #p, _ _FILE_ _, _ _LINE_ _))
#endif
/* NDEBUG */
However, the assert.h header file is not defined in the assert.h header file.
If the assert.h header file references another macro, NDEBUG, which is not defined by the assert.h header file,
and if NDEBUG is defined as a macro when assert.h is captured to the source file, the assert.h header file
simply declares the assert macro as:
#define assert(p) ((void)0)
and does not define _ _ assertfail.
10.3 Re-entrantability
Re-entrant is a state where a function called from a program can be consecutively called from another program.
The standard library of this compiler does not use static area allowing re-entrantability. Therefore, data in the
storage used by functions will not be destroyed by a call from another program.
However, the functions shown in (1) to (3) are not re-entrant.
(1) Functions that cannot be re-entranced
setjmp, longjmp, atexit, exit
(2) Functions that use the area secured in the startup routine
div, ldiv, brk, sbrk, rand, srand, strtok
(3) Functions that deal with floating-point numbers
sprintf, sscanf, printf, scanf, vprintf, vsprintf
Note
, atof, strtod, and
all the mathematical functions
Note Among sprintf, sscanf, printf, scanf, vprintf, and vsprintf, functions that do not support floating-
point numbers are re-entrant.
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10.4 Standard Library Functions
This section explains the standard library functions of this C compiler classified by function as follows. All standard
library functions are supported even when the ZF option is specified.
Item (1-x)
Character and character string functions
Item (2-x)
Program control functions
Item (3-x)
Special functions
Item (4-x)
I/O functions
Item (5-x)
Utility functions
Item (6-x)
Character string/memory functions
Item (7-x)
Mathematical functions
Item (8-x)
Diagnostic functions
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1-1
is
Character & String Functions
FUNCTION
is
judges the type of character.
HEADER
ctype.h for all the character functions
FUNCTION PROTOTYPE
int is
(int c);
Function
Arguments
Return Value
is
c... Character to be judged
1 if character c is included in
the character range.
0 if character c is not included
in the character range.
EXPLANATION
Function
Character Range
isalpha
Alphabetic character A to Z or a to z
isupper
Uppercase letters A to Z
islower
Lowercase letters a to z
isdigit
Numeric characters 0 to 9
isalnum
Alphanumeric characters 0 to 9 and A to Z or a to z
isxdigit
Hexadecimal numbers 0 to 9 and A to F or a to f
isspace
White-space characters (space, tab, carriage return, line feed,
vertical tab, and form feed)
ispunct
Punctuation characters except white-space characters
isprint
Printable characters
isgraph
Printable nonblank characters
iscntrl
Control characters
isascii
ASCII character set
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1-2
toupper,
Character & String Functions
tolower
FUNCTION
The character functions toupper and tolower both convert one type of character to another.
The toupper function returns the uppercase equivalent of c if c is a lowercase letter.
The tolower function returns the lowercase equivalent of c if c is a uppercase letter.
HEADER
ctype.h
FUNCTION PROTOTYPE
int to
(int c);
Function
Arguments
Return Value
toupper, tolower
c
... Character to be converted
Uppercase equivalent if c is a
convertible character.
Character "c" is returned
unchanged if not convertible.
EXPLANATION
toupper
The toupper function checks to see if the argument is a lowercase letter and if so converts the letter to its
uppercase equivalent.
tolower
The tolower function checks to see if the argument is a uppercase letter and if so converts the letter to its
lowercase equivalent.
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1-3
toascii
Character & String Functions
FUNCTION
The character function toascii converts "c" to an ASCII code.
HEADER
ctype.h
FUNCTION PROTOTYPE
int toascii (int c);
Function
Arguments
Return Value
toascii
c... Character to be converted
Value obtained by converting
the bits outside the ASCII
code range of "c" to 0.
EXPLANATION
The toascii function converts the bits (bits 7 to 15) of "c" outside the ASCII code range of "c" (bits 0 to 6) to "0"
and returns the converted bit value.
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1-4
_toupper/toup
Character & String Functions
_tolower/tolow
FUNCTION
The character function _toupper/toup subtracts "a" from "c" and adds "A" to the result.
The character function _tolower/tolow subtracts "A" from "c" and adds "a" to the result.
(_toupper is exactly the same as toup, and _tolower is exactly the same as tolow)
Remark
a: Lowercase, A: Uppercase
HEADER
ctype.h
FUNCTION PROTOTYPE
int _to
(int c);
Function
Arguments
Return Value
_toupper
toup
c... Character to be converted
Value obtained by adding "A"
to the result of subtraction "c" -
"a"
_tolower
tolow
Value obtained by adding "a"
to the result of subtraction "c" -
"A"
Remark
a: Lowercase, A: Uppercase
EXPLANATION
_toupper
The _toupper function is similar to toupper except that it does not test to see if the argument is a lowercase
letter.
_tolower
The _tolower function is similar to tolower, except it does not test to see if the argument is an uppercase
letter.
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2-1
setjmp,
Program Control Functions
longjmp
FUNCTION
The program control function setjmp saves the environment information when a call to this function is made.
The program control function longjmp restores the environment information saved by setjmp.
HEADER
setjmp. h
FUNCTION PROTOTYPE
int setjmp (jmp_buf env);
void longjmp (jmp_buf env, int val);
(jmp_buf is typedef defined with setjmp.h.)
Function
Arguments
Return Value
setjmp
env ... Array to which
environment information is to
be saved
0 if called directly
Value given by "val" if
returning from the
corresponding longjmp or 1
if "val " is 0
longjmp
env ... Array to which
environment information was
saved by setjmp
val ... Return value to setjmp
longjmp will not return
because program execution
resumes at statement next to
setjmp that saved
environment to "env".
EXPLANATION
setjmp
The setjmp function saves the RP3, RG4, RG5 registers, saddr area and SP to be used as variable registers,
and the return address of the functions to the array (or information block) referred to as env and returns 0.
longjmp
The longjmp function restores the environment information (RP3, RG4, RG5 registers, saddr area and SP to
be used as variable registers) saved to env. Program execution continues as if the value given by val (or 1 if
the value of val is 0) was returned by the corresponding setjmp.
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3-1
va_start,
Special Functions
va_starttop,
va_arg,
va_end
FUNCTION
The va_start function (macro) is used to start a variable argument list.
The va_starttop function (macro) is used to start a variable argument list.
The va_arg function (macro) obtains the value of an argument from a variable argument list.
The va_end function (macro) indicates that the end of a variable argument list is reached.
HEADER
stdarg. h
FUNCTION PROTOTYPE
void va_start (va_list ap, parmN);
void va_starttop(va_list ap,parmN);
type va_arg (va_list ap, type);
void va_end (va_list ap);
va-list is typedef defined with stdarg.h.
Function
Arguments
Return Value
va_start
va_starttop
va_list ..... Variable
argument list
ap ... Variable to be
initialized so that it can be
used in va_arg and va_end
parmN ... Name of last
parameter in function
prototype (one immediately
proceeding ellipsis "...")
None
va_arg
va_list ap ... Variable
argument list. ap must be set
up with call to va_start before
calling va_arg type... Type of
argument to be obtained
Next value from argument list;
0 if ap is a null pointer
va_end
va_list ap .... Variable
argument list. ap must be set
up with call to va_start before
calling va_arg.
None
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va_start,
Special Functions
va_starttop,
va_arg,
va_end
EXPLANATION
va_start
In the va_start macro, the argument ap (argument pointer) must be a va_list type (char* type) object.
A pointer to the next argument of parmN is stored in ap.
parmN is the name of the last (rightmost) parameter specified in the function's prototype.
If parmN has the register storage class, proper operation of this function is not guaranteed.
If parmN is the first argument, proper operation of this function is not guaranteed.
va_starttop
When the -ZO option (old function interface supporting option) is not specified, the va_start function cannot
be specified for the first argument because the first argument is passed via the register.
Use the macro in the following manner when the -ZO option is not specified.
Use the va_starttop macro when specifying the first argument.
Use the va_start macro when specifying the second argument.
va_arg
In the va_arg macro, the argument ap must be the same as the va_list type object initialized with va_start.
After the argument pointer ap has been initialized via a call to va_start, parameters are returned via calls to
va_arg, with type being the type of the next parameter. (Each call to va_arg obtains the next value from the
argument list.)
If the argument pointer ap is a null pointer, 0 (of type type) is returned.
va_end
The va_end macro sets a null pointer in the argument pointer ap to inform the macro processor that all the
parameters in the variable argument list have been processed.
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4-1
sprintf
I/O Functions
FUNCTION
sprintf writes data into a character string according to the format.
HEADER
stdio.h
FUNCTION PROTOTYPE
int sprintf (char *s,const char *format,...);
Function
Arguments
Return Value
sprintf
s ... Pointer to the string into
which the output is to be
written
format ... Pointer to the string
that indicates format
commands
... ... Zero or more arguments
to be converted
Number of characters written
in s (Terminating null
character is not counted.)
EXPLANATION
If there are fewer actual arguments than the formats, the proper operation is not guaranteed. If the formats run
out despite the fact that actual arguments still remain, the excess actual arguments are only evaluated and
ignored.
sprintf converts zero or more arguments that follow format according to the format command specified by
format and writes (copies) them into the string s.
Zero or more format commands may be used. Ordinary characters (other than format commands that begin
with a % character) are output as is to the string s. Each format command takes zero or more arguments that
follow format and outputs them to the string s.
Each format command begins with a % character and is followed by these:
Zero or more flags (to be explained later) that modify the meaning of the format command
Optional decimal integer that specifies a minimum field width
If the output width after the conversion is less than this minimum field width, this specifier pads the output
with spaces or zeros on its left. (If the left-justifying flag "
-" (minus) sign follows %, zeros are padded out
to the right of the output.)
The default padding is done with spaces. If the output is to be padded with 0s, place a 0 before the field
width specifier. If the number or string is greater than the minimum field width, it will be printed in full
even if the minimum is exceeded.
Optional precision (number of decimal places) specification (. integer)
With d, i, o, u, x, and X type specifiers, the minimum number of digits is specified. With the s type
specifier, the maximum number of characters (maximum field width) is specified. The number of digits to
be output following the decimal point is specified for e, E, and f conversions. The number of maximum
effective digits is specified for g and G conversions. This precision specification must be made in the
form of (.integers). If the integer part is omitted, 0 is assumed to have been specified. The amount of
padding resulting from this precision specification takes precedence over the padding by the field width
specification.
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sprintf
I/O Functions
Optional h, l and L modifiers
The h modifier instructs the sprintf function to perform the d, i, o, u, x, or X type conversion that follows
this modifier on short int or unsigned short int type. The h modifier instructs the sprintf function to
perform the n type conversion that follows this modifier on a pointer to short int type.
The l modifier instructs the sprintf function to perform the d, i, o, u, x, or X type conversion that follows
this modifier on long int or unsigned long int type. The h modifier instructs the sprintf function to
perform the n type conversion that follows this modifier on a pointer to long int type.
For other type specifiers, the h, l or L modifier is ignored.
Character that specifies the conversion (to be explained later)
In the minimum field width or precision (number of decimal places) specification, * may be used in place
of an integer string. In this case, the integer value will be given by the int argument (before the argument
to be converted). Any negative field width resulting from this will be interpreted as a positive field that
follows the
- (minus) flag. All negative precision will be ignored.
The following flags are used to modify a format command.
.................
The result of a conversion is left-justified within the field.
+ .................
The result of a signed conversion always begins with a + or
- sign.
space..........
If the result of a signed conversion has no sign, a space is prefixed to the output. If the +
(plus) flag and space flag are specified at the same time, the space flag will be ignored.
# .................
The result is converted in the assignment form.
In the o type conversion, precision is increased so that the first digit becomes 0. In the x or X
type conversion, 0x or 0X is prefixed to a nonzero result. In the e, E, and f type conversions,
a decimal point is forcibly inserted to all the output values (in the default without #, a decimal
point is displayed only when there is a value to follow).
In the g and G type conversions, a decimal point is forcibly inserted to all the output values,
and truncation of 0 to follow will not be allowed (in the default without #, a decimal point is
displayed only when there is a value to follow. The 0 to follow will be truncated). In all the
other conversions, the # flag is ignored.
The format codes for output conversion specifications are as follows.
d ................. Converts int argument to signed decimal format.
i .................. Converts int argument to signed decimal format.
o ................. Converts int argument to unsigned octal format.
u ................. Converts int argument to unsigned decimal format.
x ................. Converts int argument to unsigned hexadecimal format (with lowercase letters abcdef).
X ................. Converts int argument to unsigned hexadecimal format (with uppercase letters ABCDEF).
With d, i, o, u, x and X type specifiers, the minimum number of digits (minimum field width) of the result is
specified. If the output is shorter than the minimum field width, it is padded with zeros. If no precision is
specified, 1 is assumed to have been specified. Nothing will appear if 0 is converted with 0 precision.
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sprintf
I/O Functions
f .................. Converts double argument as a signed value with [
-] dddd.dddd format.
dddd is one or more decimal number(s). The number of digits before the decimal point is
determined by the absolute value of the number, and the number of digits after the decimal
point is determined by the required precision. When the precision is omitted, it is interpreted
as 6.
e ................. Converts double argument as a signed value with [
-] d.dddd e [sign] ddd format. d is one
decimal number, and dddd is one or more decimal number(s). ddd is exactly a three-digit
decimal number, and the sign is + or
-. When the precision is omitted, it is interpreted as 6
E ................. The same format as that of e except E is added instead of e before the exponent.
g ................. Uses whichever shorter method of f or e format when converting double argument based on
the specified precision. e format is used only when the exponent of the value is smaller than
-
4 or larger than the specified number by precision.
The following 0 are truncated, and the decimal point is displayed only when one or more
numbers follow.
G................. The same format as that of g except E is added instead of e before the exponent.
c ................. Converts int argument to unsigned char and writes the result as a single character.
s ................. The associated argument is a pointer to a string of characters and the characters in the string
are written up to the terminating null character (but not included in the output). If precision is
specified, the characters exceeding the maximum field width will be truncated off the end.
When the precision is not specified or larger than the array, the array must include a null
character.
p ................. The associated argument is a pointer to void and the pointer value is displayed in unsigned
hexadecimal 4 digits (with 0s prefixed to less than a 4-digit pointer value). In the case of the
large model, the pointer value is displayed in unsigned hexadecimal 8 digits (the higher 2
digits are padded by 0 and displayed with 0s prefixed to less than a 6-digit pointer value). The
precision specification if any will be ignored.
n ................. The associated argument is an integer pointer into which the number of characters written thus
far in the string "s" is placed. No conversion is performed.
% ................ Prints a % sign. The associated argument is not converted (but the flag and minimum field
width specifications are effective).
Operations for invalid conversion specifiers are not guaranteed.
When the actual argument is a union or a structure, or the pointer to indicate them (except the character
type array in % s conversion or the pointer in % p conversion), operations are not guaranteed.
The conversion result will not be truncated even when there is no field width or the field width is small. In
other words, when the number of characters of the conversion result are larger than the field width, the
field is extended to the width that includes the conversion result.
The formats of the special output character string in %f, %e, %E, %g, %G conversions are shown below.
non-numeric
"(NaN)"
+
"(+INF)"
"(INF)"
sprintf writes a null character at the end of the string s. (This character is included in the return value count.)
The syntax of format commands is illustrated in Figure 10-3.
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Figure 10-3. Syntax of Format Commands
Format command
Ordinary char.
Format:
Characters except %
Ordinary
characters:
Flags
L
Format command:
%
Min. field width
Precision
h
Format code
+
Space
#
Flags:
Digits
Precision:
*
Digits
Minimum field width:
*
Format codes:
d
i
o
I
u
x
X
c
s
p
n
f
e
E
g
G
%
.
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4-2
sscanf
I/O Functions
FUNCTION
sscanf reads data from the input string according to the format.
HEADER
stdio.h
FUNCTION PROTOTYPE
int sscanf (const char *s, const char *format,...);
Function
Arguments
Return Value
sscanf
s ... Pointer to the input string
format ... Pointer to the string
that indicates the input format
commands
... ... Pointer to object in which
converted values are to be
stored, and zero or more
arguments
1 if the string s is empty.
Number of assigned input data
items if the string s is not
empty.
EXPLANATION
sscanf inputs data from the string pointed to by s. The string pointed to by format specifies the input string
allowed for input. Zero or more arguments after format are used as pointers to an object. format specifies
how data is to be converted from the input string.
If there are insufficient arguments to match the format commands pointed to by format, proper operation by
the compiler is not guaranteed.
For excessive arguments, expression evaluation will be performed but no data will be input.
The control string pointed to by format consists of zero or more format commands classified into the
following three types.
(1) White-space characters (one or more characters for which isspace becomes true)
(2) Non-white-space characters (other than %)
(3) Format specifiers
Each format specifier begins with the % character and is followed by these:
Optional * character which suppresses assignment of data to the corresponding argument
Optional decimal integer which specifies a maximum field width
Optional h, l or L modifier which indicates the object size on the receiving side
If h precedes the d, i, o, or x format specifier, the argument is a pointer to not int but short int.
If l precedes any of these format specifiers, the argument is a pointer to long int.
Likewise, if h precedes the u format specifier, the argument is a pointer to unsigned short int.
If l precedes the u format specifier, the argument is a pointer to unsigned long int.
If l precedes the conversion specifier e, E, f, g, G, the argument is a pointer to double (a pointer to float
in default without l). If L precedes, it is ignored.
Remark
Conversion specifier: Character to indicate the type of corresponding conversion (to be
described later)
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sscanf
I/O Functions
sscanf executes the format commands in "format" in sequence and if any format command fails, the function
will terminate.
(1) A white-space character in the control string causes sscanf to read any number (including zero) of
white-space characters up to the first non-white-space character (which will not be read). This white-
space character command fails if it does not encounter any non-white-space characters.
(2) A non-white-space character causes sscanf to read and discard a matching character. This command
fails if the specified character is not found.
(3) The format commands define a collection of input streams for each type specifier (to be detailed later).
The format commands are executed according to the following steps.
The input white-space characters (specified by isspace) are skipped over, except when the type
specifier is [, c, or n.
The input data items are read from the string "s", except when the type specifier is n. The input data
items are defined as the longest input stream of the first partial stream of the string indicated by the
type specifier (but up to the maximum field width if so specified). The character next to the input data
items is interpreted as not have been read. If the length of the input data items is 0, the format
command execution fails.
The input data items (number of input characters with the type specifier n) are converted to the type
specified by the type specifier except the type specifier %. If the input data items do not match the
specified type, the command execution fails. Unless assignment is suppressed by *, the result of the
conversion is stored in the object pointed to by the first argument that follows "format" and has not yet
received the result of the conversion.
The following type specifiers are available.
d ....................... Reads a decimal integer (which may be signed). The corresponding argument must be a
pointer to an integer.
i ........................ Reads an integer (which may be signed). If a number is preceded by 0x or 0X, the number
is interpreted as a hexadecimal integer. If a number is preceded by 0, the number is
interpreted as an octal integer. Other numbers are regarded as decimal integers. The
corresponding argument must be a pointer to an integer.
o ....................... Reads an octal integer (which may be signed). The corresponding argument must be a
pointer to an integer.
u ....................... Reads an unsigned decimal integer.
The corresponding argument must be a pointer to an unsigned integer.
x ....................... Reads a hexadecimal integer (which may be signed).
e, E, F, g, G...... A floating-point value consists of an optional sign (+ or ), one or more consecutive
decimal number(s) including a decimal point, an optional exponent (e or E), and the
following optional signed integer value. When overflow occurs as a result of conversion, or
when underflow occurs with the conversion result
, a non-normalized number or 0
becomes the conversion result. The corresponding argument is a pointer to float. The
corresponding argument must be a pointer to the first character of an array that has
sufficient size to accommodate this character string and a null terminator. The null
terminator will be automatically added.
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sscanf
I/O Functions
s ................. Inputs a character string consisting of a non-blank character string. The corresponding
argument is a pointer to an integer. 0x or 0X can be allocated at the first hexadecimal integer.
The corresponding argument must be a pointer an array that has sufficient size to
accommodate this character string and a null terminator. The null terminator will be
automatically added.
[ .................. Inputs a character string consisting of expected character groups (called a scanset). The
corresponding argument must be a pointer to the first character of an array that has sufficient
size to accommodate this character string and a null terminator. The null terminator will be
automatically added. The format commands continue from this character up to the closing
square bracket (]). The character string (called a scanlist) enclosed in the square brackets
constitutes a scanset except when the character immediately after the opening square
bracket is a circumflex (^).
When the character is a circumflex, all the characters other than a scanlist between the
circumflex and the closing square bracket constitute a scanset. However, when a scanlist
begins with [ ] or [^], this closing square bracket is contained in the scanlist and the next
closing square brocket becomes the end of the scanlist. A hyphen () at other than the left or
right end of a scanlist is interpreted as the punctuation mark for hyphenation if the character
at the left of the range specifying hyphen () is not smaller than the right-hand character in
ASCII code value.
c ................. Inputs a character string consisting of the number of characters specified by the field width. (If
the field width specification is omitted, 1 is assumed.) The corresponding argument must be a
pointer to the first character of an array that has sufficient size to accommodate this character
string. The null terminator will not be added.
p ................. Reads an unsigned hexadecimal integer. The corresponding argument must be a pointer to
void pointer. For the large model, a hexadecimal 8-digit integer is input, and the higher two
digits are ignored.
n ................. Receives no input from the string s. The corresponding argument must be a pointer to an
integer. The number of characters that are read thus far by this function from the string "s" is
stored in the object that is pointed to by this pointer. The %n format command is not included
in the return value assignment count.
% ................ Reads a % sign. Neither conversion nor assignment takes place.
If a format specification is invalid, the format command execution fails.
If a null terminator appears in the input stream, sscanf will terminate.
If an overflow occurs in an integer conversion (with the d, i, o, u, x, or p format specifier), the higher bits will
be truncated depending on the number of bits of the data type after the conversion.
The syntax of input format commands is illustrated below.
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Figure 10-4. Syntax of Input Format Commands
Command
Format:
Characters except
% and white space
Ordinary characters:
Digits
Max. field width:
\f
\n
\r
\t
\v
Space
White-space
char.
Ordinary
char.
Format
specifier
Command:
L
Format command:
%
Max. field width
h
Format specifier
*
I
Format specifiers:
d
i
o
u
x
s
c
p
n
%
f
e
E
g
G
scanlist
scanlist:
Characters
except
Characters
except
^
White-space
characters:
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4-3
printf
I/O Functions
FUNCTION
printf outputs data to SFR according to the format.
HEADER
stdio.h
FUNCTION PROTOTYPE
int printf (const char *format, ...);
Function
Arguments
Return Value
printf
format ...Pointer to the
character string that indicates
the output conversion
specification
... ... 0 or more arguments to
be converted
Number of characters output
to s (the null character at the
end is not counted)
EXPLANATION
(0 or more) arguments following the format are converted and output using the putchar function, according to
the output conversion specification specified in the format.
The output conversion specification is 0 or more directives. Normal characters (other than conversion
specifications starting with %) are output as is using the putchar function. The conversion specification is
output using the putchar function by fetching and converting the following (0 or more) arguments.
Each conversion specification is the same as that of the sprintf function.
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4-4
scanf
I/O Functions
FUNCTION
scanf reads data from SFR according to the format.
HEADER
stdio.h
FUNCTION PROTOTYPE
int scanf (const char *format, ...);
Function
Arguments
Return Value
scanf
format ... Pointer to the
character string to indicate
input conversion specification
format
... ... Pointer (0 or more)
argument to the object to
assign the converted value
When the character string s is
not null ... number of input
items assigned
EXPLANATION
Performs input using the getchar function. Specifies the input string permitted by the character string
indicated by format. Uses the arguments after format as pointers to an object. format specifies how the
conversion is performed by the input string.
When there are not enough arguments for format, normal operation is not guaranteed. When the number of
arguments is excessive, the expression will be evaluated but not input.
format consists of 0 or more directives. The directives are as follows.
(1) One or more null character (character that makes isspace true)
(2) Normal character (other than %)
(3) Conversion indication
If a conversion ends with an input character that conflicts with the directive, the conflicting input character is
rounded down. The conversion indication is the same as that of the sscanf function.
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4-5
vprintf
I/O Functions
FUNCTION
vprintf outputs data to SFR according to the format.
HEADER
stdio.h
FUNCTION PROTOTYPE
int vprintf (const char *format, va_list p) ;
Function
Arguments
Return Value
vprintf
format ... Pointer to the
character string that indicates
output conversion
specification
p ... Pointer to the argument
list
Number of output characters
(the null character at the end
is not counted)
EXPLANATION
The argument that the pointer of the argument list indicates is converted and output using the putchar
function according to the output conversion specification specified by the format.
Each conversion specification is the same as that of the sprintf function.
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4-6
vsprintf
I/O Functions
FUNCTION
vsprintf writes data to character strings according to the format.
HEADER
stdio.h
FUNCTION PROTOTYPE
int vsprintf (char *s, const char * format, va_list p) ;
Function
Arguments
Return Value
vsprintf
s ... Pointer to the character
string that writes the output
format ... Pointer to the
character string that indicates
output conversion
specification
p ... Pointer to the argument
list
Number of characters output
to s (the null character at the
end is not counted)
EXPLANATION
Writes out the argument that the pointer of argument list indicates to the character strings indicated by s
according to the output conversion specification specified by format.
The output specification is the same as that of the sprintf function.
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4-7
getchar
I/O Functions
FUNCTION
getchar reads a character from SFR.
HEADER
stdio.h.
FUNCTION PROTOTYPE
int getchar (void);
Function
Arguments
Return Value
getchar
None
A character read from SFR
EXPLANATION
Returns the value read from SFR symbol P0 (port 0).
An error check related to reading is not performed.
To change the SFR to be read, it is necessary to either change the source and re-register it to the library or
create a new getchar function.
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4-8
gets
I/O Functions
FUNCTION
gets reads a character string.
HEADER
stdio.h
FUNCTION PROTOTYPE
char *gets (char *s);
Function
Arguments
Return Value
gets
s ... Pointer to input character
string
Normal ... s
If the end of the file is
detected without reading a
character
... null pointer
EXPLANATION
Reads a character string using the getchar function and stores in the array that s indicates.
When the end of the file is detected (getchar function returns
-1) or when a line feed character is read, the
reading of a character string ends. The line feed character read is abandoned, and a null character is written
at the end of the character stored in the array in the end.
When the return value is normal, it returns s.
When the end of the file is detected and no character is read in the array, the contents of the array remain
unchanged, and a null pointer is returned.
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4-9
putchar
I/O Functions
FUNCTION
putchar outputs a character to SFR.
HEADER
stdio.h
FUNCTION PROTOTYPE
int putchar (int c);
Function
Arguments
Return Value
putchar
c ... Character to be output
character to have been output
EXPLANATION
Writes the character specified by c to the SFR symbol P0 (port 0) (converted to unsigned char type).
An error check related to writing is not performed.
To change the SFR to be written, it is necessary to either change the source and re-register to the library or
user create a new putchar function.
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4-10
puts
I/O Functions
FUNCTION
puts outputs a character string.
HEADER
stdio.h
FUNCTION PROTOTYPE
int puts (const char *s);
Function
Arguments
Return Value
puts
s ...Pointer to an output
character string
Normal ... 0
When putchar function
returns 1 ... 1
EXPLANATION
Writes the character string indicated by s using the putchar function and adds a line feed character at the end
of the output.
Writing of the null character at the end of the character string is not performed.
When the return value is normal, 0 is returned, and when the putchar function returns 1, 1 is returned.
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5-1
atoi, Utility
Functions
atol
FUNCTION
The string function atoi converts the contents of a decimal integer string to an int value.
The string function atol converts the contents of a decimal integer string to a long value.
HEADER
stdlib. h
FUNCTION PROTOTYPE
int atoi (const char *nptr);
long int atol (const char *nptr);
Function
Arguments
Return Value
atoi
nptr... String to be converted
int value if converted
properly
INT_MAX (32767) if positive
overflow occurs
INT_MIN (32768) if
negative overflow occurs
0 if the string is invalid
atol
long int value if converted
properly
LONG_MAX (2147483647)
for positive overflow
LONG_MIN (2147483648)
for negative overflow
0 if the string is invalid
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atoi, Utility
Functions
atol
EXPLANATION
atoi
The atoi function converts the first part of the string pointed to by pointer "nptr" to an int value. The string
may consist of zero or more white-space characters possibly followed by a minus or plus sign, followed by a
string of digits.
The atoi function skips over zero or more white-space characters (for which isspace becomes true) from the
beginning of the string and converts the string from the character next to the skipped white-spaces to an int
value (until other than digits or a null character appears in the string).
If no digits to convert are found in the string, the function returns 0. If an overflow occurs, the function returns
INT_MAX (32767) for a positive overflow and INT_MIN (
-32768) for a negative overflow.
atol
The atol function converts the first part of the string pointed to by pointer "nptr" to a long value. The string
may consist of zero or more white-space characters, possibly followed by a minus or plus sign, followed by a
string of digits.
The atol function skips over zero or more white-space characters (for which isspace becomes true) from the
beginning of the string and converts the string from the character next to the skipped white-spaces to a long
value (until other than digits or null character appears in the string).
If no digits to convert are found in the string, the function returns 0. If an overflow occurs, the function returns
LONG_MAX (2147483647) for a positive overflow and LONG_MIN (
-2147483648) for a negative overflow.
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5-2
strtol,
Utility Functions
strtoul
FUNCTION
The string function strtol converts a string to a long integer.
The string function strtoul converts a string to an unsigned long integer.
HEADER
stdlib. h
FUNCTION PROTOTYPE
long int strtol (const char *nptr, char **endptr, int base);
unsigned long int strtoul (const char *nptr, char **endptr, int base);
Function
Arguments
Return Value
strtol
nptr... String to be converted
endptr ... Address of char
pointer
base ... Base for number
represented in the string
long int value if converted
properly
LONG_MAX
(2147483647) for positive
overflow
LONG_MIN
(2147483648) for negative
overflow
0 if not converted
strtoul
unsigned long if converted
properly
ULONG_MAX
(4294967295U) if overflow
occurs
0 if not converted
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strtol,
Utility Functions
strtoul
EXPLANATION
strtol
The strtol function decomposes the string pointed by pointer nptr into the following three parts.
(1) String of white-space characters that may be empty (to be specified by isspace)
(2) Integer representation by the base determined by the value of "base"
(3) String of one or more characters that cannot be recognized (including null terminators)
The strtol function converts part (2) of the string into a long integer and returns this integer value.
A base of 0 indicates that the base should be determined from the leading digits of the string. A leading 0x or
0X indicates a hexadecimal number; a leading 0 indicates an octal number; otherwise, the number is
interpreted as decimal. (In this case, the number may be signed.)
If the base is 2 to 36, the set of letters from a to z or A to Z which can be part of a number (and which may be
signed) with any of these bases are taken to represent 10 to 35. A leading 0x or 0X is ignored if the base is
16.
If endptr is not a null pointer, a pointer to part (3) of the string is stored in the object pointed to by endptr.
If the correct value causes an overflow, the function returns LONG_MAX (2147483647) for the positive
overflow or LONG_MIN (
-2147483648) for the negative overflow depending on the sign and sets errno to
ERANGE (2).
If the string in (2) is empty or the first non-white-space character of the string (2) is not appropriate for an
integer with the given base, the function performs no conversion and returns 0. In this case, the value of the
string nptr is stored in the object pointed to by endptr (if it is not a null string). This holds true with the bases
0 and 2 to 36.
strtoul
The strtoul function decomposes the string pointed by pointer nptr into the following three parts.
(1) String of white-space characters that may be empty (to be specified by isspace)
(2) Integer representation by the base determined by the value of base
(3) String of one or more characters that cannot be recognized (including null terminators)
The strtoul function converts part (2) of the string into a unsigned long integer and returns this unsigned
long integer value.
A base of 0 indicates that the base should be determined from the leading digits of the string. A leading 0x or
0X indicates a hexadecimal number; a leading 0 indicates an octal number; otherwise, the number is
interpreted as decimal.
If the base is 2 to 36, the set of letters from a to z or A to Z which can be part of a number (and which may be
signed) with any of these bases are taken to represent 10 to 35. A leading 0x or 0X is ignored if the base is
16.
If endptr is not a null pointer, a pointer to part (3) of the string is stored in the object pointed to by endptr.
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strtol,
Utility Functions
strtoul
If the correct value causes an overflow, the function returns ULONG_MAX (4294967295U) and sets errno to
ERANGE (2).
If the string in (2) is empty or the first non-white-space character of the string in (2) is not appropriate for an
integer with the given base, the function performs no conversion and returns 0. In this case, the value of the
string nptr is stored in the object pointed to by endptr (if it is not a null string). This holds true with the bases
0 and 2 to 36.
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5-3
calloc
Utility Functions
FUNCTION
The memory function calloc allocates an array area and then initializes the area to 0.
HEADER
stdlib. h
FUNCTION PROTOTYPE
void *calloc (size_t nmemb, size_t size);
Function
Arguments
Return Value
calloc
nmemb ... Number of
members in the array
size ... Size of each member
Pointer to the beginning of
the allocated area if the
requested size is allocated
Null pointer if the requested
size is not allocated
EXPLANATION
The calloc function allocates an area for an array consisting of n number of members (specified by nmemb),
each of which has the number of bytes specified by size and initializes the area (array members) to zero.
If memory cannot be allocated, the function returns a null pointer. (This memory allocation will start from a
break value and the address next to the allocated space will become a new break value. See 5-11 brk for
break value setting with the memory function brk.)
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5-4
free
Utility Functions
FUNCTION
The memory function free releases the allocated block of memory.
HEADER
stdlib. h
FUNCTION PROTOTYPE
void free (void *ptr);
Function
Arguments
Return Value
free
ptr ... Pointer to the beginning
of block to be released
None
EXPLANATION
The free function releases the allocated space (before a break value) pointed to by ptr. (malloc, calloc, or
realloc called after free will allocate space that was freed earlier.)
If ptr does not point to the allocated space, free will take no action. (Freeing the allocated space is performed
by setting ptr as a new break value.)
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5-5
malloc
Utility Functions
FUNCTION
The memory function malloc allocates a block of memory.
HEADER
stdlib. h
FUNCTION PROTOTYPE
void *malloc (size_t size);
Function
Arguments
Return Value
malloc
size ... Size of memory block
to be allocated
Pointer to the beginning of
the allocated area if the
requested size is allocated
Null pointer if the requested
size is not allocated
EXPLANATION
The malloc function allocates a block of memory for the number of bytes specified by size and returns a
pointer to the first byte of the allocated area.
If memory cannot be allocated, the function returns a null pointer. (This memory allocation will start from a
break value and the address next to the allocated area will become a new break value. See 5-11 brk for
break value setting with the memory function brk.)
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5-6
realloc
Utility Functions
FUNCTION
The memory function realloc reallocates a block of memory (namely, changes the size of the allocated memory).
HEADER
stdlib. h
FUNCTION PROTOTYPE
void *realloc (void *ptr, size_t size);
Function
Arguments
Return Value
realloc
ptr ... Pointer to the beginning
of block previously allocated
size ... New size to be given to
this block
Pointer to the beginning of
the reallocated space if the
requested size is
reallocated
Pointer to the beginning of
the allocated space if ptr is
a null pointer
Null pointer if the requested
size is not reallocated or
"ptr" is not a null pointer
EXPLANATION
The realloc function changes the size of the allocated space (before a break value) pointed to by ptr to that
specified by size.
If the value of size is greater than the size of the allocated space, the contents of the allocated space up to
the original size will remain unchanged. The realloc function allocates only for the increased space. If the
value of size is less than the size of the allocated space, the function will free the reduced space of the
allocated space.
If ptr is a null pointer, the realloc function will newly allocate a block of memory of the specified size (same as
malloc).
If ptr does not point to the block of memory previously allocated or if no memory can be allocated, the function
executes nothing and returns a null pointer.
(Reallocation will be performed by setting the address of ptr plus the number of bytes specified by size as a
new break value.)
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5-7
abort
Utility Functions
FUNCTION
The program control function abort causes immediate, abnormal termination of a program.
HEADER
stdlib. h
FUNCTION PROTOTYPE
void abort (void);
Function
Arguments
Return Value
abort
None
No return to its caller.
EXPLANATION
The abort function loops and can never return to its caller.
The user must create the abort processing routine.
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5-8
atexit,
Utility Functions
exit
FUNCTION
atexit registers the function called at the normal termination.
exit terminates a program.
HEADER
stdlib. h
FUNCTION PROTOTYPE
int atexit (void(*func) (void));
void exit (int status);
Function
Arguments
Return Value
atexit
func ... Pointer to function to
be registered
0 if function is registered as
wrap-up function
1 if function cannot be
registered
exit
status ... Status value
indicating termination
exit can never return.
EXPLANATION
atexit
The atexit function registers the wrap-up function pointed to by func so that it is called without argument upon
normal program termination by calling exit or returning from main.
Up to 32 wrap-up functions may be established. If the wrap-up function can be registered, atexit returns 0. If
no more wrap-up functions can be registered because 32 wrap-up functions have already been registered, the
function returns 1.
exit
The exit function causes immediate, normal termination of a program.
This function calls the wrap-up functions in the reverse of the order in which they were registered with atexit.
The exit function loops and can never return to its caller.
The user must create the exit processing routine.
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5-9
abs, Utility
Functions
labs
FUNCTION
The mathematical function abs returns the absolute value of its int type argument.
The mathematical function labs returns the absolute value of its long type argument.
HEADER
stdlib. h
FUNCTION PROTOTYPE
int abs (int j);
long int labs (long int j);
Function
Arguments
Return Value
abs
j ... Any signed integer for
which absolute value is to be
obtained
Absolute value of j if j falls
within
32767
j 32767
32768 (0x8000) if j is
32768
labs
j ... Any long integer for which
absolute value is to be
obtained
Absolute value of j if j falls
within
2147483647
j
2147483647
2147483648
(0x80000000) if the value of
j is 2147483648
EXPLANATION
abs
The abs returns the absolute value of its int type argument. If j is 32768, the function returns 32768.
labs
The labs returns the absolute value of its long type argument. If the value of j is 2147483648, the function
returns 2147483648.
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div,
Utility Functions
ldiv
FUNCTION
The mathematical function div performs the integer division of numerator divided by denominator.
The mathematical function ldiv performs the long integer division of numerator divided by denominator.
HEADER
stdlib.h
FUNCTION PROTOTYPE
div_t div (int numer, int denom);
ldiv_t ldiv (long int numer, long int denom);
Function
Arguments
Return Value
div
numer ... Numerator of the
division
denom ... Denominator of the
division
Quotient to the quot element
of structure type
div_t and the remainder to the
rem element
ldiv
Quotient to the quot element
of structure type
ldiv_t and the remainder to
the rem element
EXPLANATION
div
The div function performs the integer division of numerator divided by denominator. The result of div has a
structure type named div_t with the elements quo (quotient) and rem (remainder).
The absolute value of the quotient is defined as the largest integer not greater than the absolute value of
numer divided by the absolute value of denom. The remainder always has the same sign as the result of the
division (plus if numer and denom have the same sign; otherwise minus).
The remainder is the value of numer - denom*quotient.
If denom is 0, the quotient becomes 0 and the remainder becomes numer. If numer is
-32768 and denom
is
-1, the quotient becomes -32768 and the remainder becomes 0.
ldiv
The ldiv function performs the long integer division of numerator divided by denominator. The result of ldiv
has a structure type named "ldiv_t" with the elements quo (quotient) and rem (remainder).
The absolute value of the quotient is defined as the largest long int type integer not greater than the absolute
value of numer divided by the absolute value of denom. The remainder always has the same sign as the
result of the division (plus if numer and denom have the same sign; otherwise minus).
The remainder is the value of numer - denom*quotient.
If denom is 0, the quotient becomes 0 and the remainder becomes numer. If numer is
-2147483648 and
denom is
-1, the quotient becomes -2147483648 and the remainder becomes 0.
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5-11
brk,
Utility Functions
sbrk
FUNCTION
The memory function brk sets a break value.
The memory function sbrk increments or decrements the set break value.
HEADER
stdlib. h
FUNCTION PROTOTYPE
int brk (char *endds);
char *sbrk (int incr);
Function
Arguments
Return Value
brk
endds ... Break value to be
set
0 if break value is set
properly
1 if break value cannot be
changed
sbrk
incr ... Value (bytes) by which
set break value is to be
incremented/decremented.
Old break value if
incremented or
decremented properly
1 if old break value cannot
be incremented or
decremented
EXPLANATION
brk
The brk function sets the value given by endds as a break value (the address next to the end address of an
allocated block of memory).
If endds is outside the permissible address range, the function sets no break value and sets errno to
ENOMEM (3).
sbrk
The sbrk function increments or decrements the set break value by the number of bytes specified by incr.
(Increment or decrement is determined by the plus or minus sign of incr.)
If the incremented or decremented break value is outside the permissible address range, the function does
not change the original break value and sets errno to ENOMEM (3).
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5-12
atof
Utility Functions
strtod
FUNCTION
atof converts a decimal integer character string to double.
strtod converts a character string to double.
HEADER
stdlib.h
FUNCTION PROTOTYPE
double atof const char *nptr) ;
double strtod (const char *nptr, char **endptr) ;
Function
Arguments
Return value
atof
nptr ... Character string to be
converted
endptr ... Pointer to store a
pointer to an unidentifiable
area (strtod only)
Normal ... Converted value
When positive overflow
occurs ... HUGE_VAL (with
the sign of the overflowed
value)
When negative overflow
occurs ... 0
Illegal character string ... 0
strtod
nptr ... Character string to be
converted
endptr ... Pointer to store a
pointer to an unidentifiable
area
Normal ... Converted value
When positive overflow
occurs ... HUGE_VAL (with
the sign of the overflowed
value)
When negative overflow
occurs ... 0
Illegal character string ... 0
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atof
Utility Functions
strtod
EXPLANATION
atof
atof converts the character string that is pointed by the pointer nptr to double.
Skips 0 or more strings of null characters (a character which makes isspace true) from the start and converts
the character string (other than decimal characters or until the last null character appears) from the character
next to the floating-point number.
If the conversion is performed correctly, a floating point number is returned.
If an overflow occurs in the conversion, HUGE_VAL, which has the sign of the overflowed value, is returned,
and ERANGE is set to errno.
If annihilation of valid digits occurs due to underflow or overflow, a non-normalized number and 0 are
returned, respectively, and ERANGE is set to errno.
If a conversion cannot be performed, 0 is returned.
strtod
strtod converts the character string that is pointed by the pointer nptr to double.
Skips 0 or more strings of null characters (a character which makes isspace true) from the start and converts
the character string (other than decimal characters or until the last null character appears) from the character
next to the floating-point number.
If the conversion is performed correctly, a floating-point number is returned.
If an overflow occurs in the conversion, HUGE_VAL, which has the sign of the overflowed value, is returned,
and ERANGE is set to errno.
If annihilation of valid digits occurs due to underflow or overflow, a non-normalized number and 0 are
returned, respectively, and ERANGE is set to errno. At the same time, endptr stores the pointer in the next
character string.
If conversion cannot be performed, 0 is returned.
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itoa,
Utility Functions
ltoa,
ultoa
FUNCTION
The string function itoa converts an int integer to its string equivalent.
The string function ltoa converts a long integer to its string equivalent.
The string function ultoa converts an unsigned long integer to its string equivalent.
HEADER
stdlib. h
FUNCTION PROTOTYPE
char *itoa (int value, char *string, int radix);
char *ltoa (long value, char *string, int radix);
char *ultoa (unsigned long value, char *string, int radix);
Function
Arguments
Return Value
itoa,
ltoa,
ultoa
value ... String to which
integer is to be converted
string ... Pointer to the
conversion result
radix ... Base of output string
Pointer to the converted
string if converted properly
Null pointer if not converted
properly
EXPLANATION
itoa, ltoa, ultoa
The itoa, ltoa, and ultoa functions all convert the integer value specified by value to its string equivalent,
which is terminated with a null character, and store the result in the area pointed to by "string".
The base of the output string is determined by radix, which must be in the range 2 through 36. Each function
performs conversion based on the specified radix and returns a pointer to the converted string. If the
specified radix is outside the range 2 through 36, the function performs no conversion and returns a null
pointer.
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rand,
Utility Functions
srand
FUNCTION
The mathematical function rand generates a sequence of psuedorandom numbers.
The mathematical function srand sets a starting value (seed) for the sequence generated by rand.
HEADER
stdlib. h
FUNCTION PROTOTYPE
int rand (void);
void srand (unsigned int seed);
Function
Arguments
Return Value
rand
None
Psuedorandom integer in the
range of 0 to RAND_MAX
srand
seed ... Starting value for
psuedorandom number
generator
None
EXPLANATION
rand
Each time the rand function is called, it returns a psuedorandom integer in the range of 0 to RAND_MAX.
srand
The srand function sets a starting value for a sequence of random numbers. seed is used to set a starting
point for a progression of random numbers that is a return value when rand is called. If the same seed value
is used, the sequence of psuedorandom numbers is the same when srand is called again. Calling rand
before srand is used to set a seed is the same as calling rand after srand has been called with seed = 1.
(The default seed is 1.)
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bsearch
Utility Functions
FUNCTION
The bsearch function performs a binary search.
HEADER
stdlib. h
FUNCTION PROTOTYPE
void *bsearch (const void *key, const void *base, size_t nmemb,
size_t size, int (*compare) (const void *, const void *));
Function
Arguments
Return Value
bsearch
key ... Pointer to key for which
search is made
base ... Pointer to sorted array
that contains information to
search
nmemb ... Number of array
elements
size ... Size of an array
compare ... Pointer to function
used to compare two keys
Pointer to the first member
that matches "key" if the
array contains the key
Null pointer if the key is not
contained in the array
EXPLANATION
The bsearch function performs a binary search on the sorted array pointed to by base and returns a pointer
to the first member that matches the key pointed to by key. The array pointed to by base must be an array
that consists of nmemb number of members each of which has the size specified by size and must have
been sorted in ascending order.
The function pointed to by compare takes two arguments (key as the 1st argument and array element as the
2nd argument), compares the two arguments, and returns:
-
Negative value if the 1st argument is less than the 2nd argument
-
0 if both arguments are equal
-
Positive integer if the 1st argument is greater than the 2nd argument
When the -ZR option is specified, the function passed to the argument of the bsearch function must be a
pascal function.
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qsort
Utility Functions
FUNCTION
The qsort function sorts the members of a specified array using a quicksort algorithm.
HEADER
stdlib. h
FUNCTION PROTOTYPE
void qsort (void *base, size_t nmemb, size_t size,
int (*compare)(const void *, const void *));
Function
Arguments
Return Value
qsort
base ... Pointer to array to be
sorted
nmemb ... Number of
members in the array
size ... Size of an array
member
compare ... Pointer to function
used to compare two keys
None
EXPLANATION
The qsort function sorts the members of the array pointed to by base in ascending order. The array pointed
to by base consists of nmemb number of members each of that has the size specified by size.
The function pointed to by compare takes two arguments (array element 1 as the 1st argument and array
element 2 as the 2nd argument), compares the two arguments, and returns:
-
Negative value if the 1st argument is less than the 2nd argument
-
0 if both arguments are equal
-
Positive integer if the 1st argument is greater than the 2nd argument
If the two array elements are equal, the element nearest to the top of the array will be sorted first.
When the -ZR option is specified, the function passed to the argument of the qsort function must be a pascal
function.
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strbrk
Utility Functions
FUNCTION
strbrk sets a break value.
HEADER
stdlib.h
FUNCTION PROTOTYPE
int strbrk (char *endds);
Function
Arguments
Return Value
strbrk
endds ... Break value to be
set
Normal ... 0
When a break value cannot be
changed ... 1
EXPLANATION
Sets the value given by endds to the break value (the address following the address at the end of the area to
be allocated).
When endds is out of the permissible range, the break value is not changed. ENOMEM(3) is set to errno and
1 is returned.
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strsbrk
Utility Functions
FUNCTION
strsbrk increments/decrements a break value.
HEADER
stdlib.h
FUNCTION PROTOTYPE
char *strsbrk (int incr);
Function
Arguments
Return Value
strsbrk
incr ... Amount by which a
break value is to be
incremented/decremented
Normal ... Old break value
When a break value cannot be
incremented/decremened ... 1
EXPLANATION
incr byte increments/decrements a break value (depending on the sign of incr).
When the break value is out of the permissible range after incrementing/decrementing, the break value is not
changed. ENOMEM(3) is set to errno, and
-1 is returned.
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VWULWRD
8WLOLW\ )XQFWLRQV
VWUOWRD
VWUXOWRD
FUNCTION
stritoa
converts int to a character string.
strltoa
converts long to a character string.
strultoa
converts unsigned long to a character string.
HEADER
stdllib.h
FUNCTION PROTOTYPE
char *stritoa (int value, char *string, int radix);
char *strltoa (long value, char *string, int radix);
char *strultoa (unsigned long value, char *string, int radix);
Function
Arguments
Return Value
stritoa
strltoa
strultoa
value ... Character string to
convert
string ... Pointer to conversion
result
radix ... Radix to specify
Normal ... Pointer to the
converted character string
Other ... Null pointer
EXPLANATION
stritoa, strltoa, strultoa
Converts the specified numeric value value to the character string that ends with a null character, and stores
the result in the area specified with string. The conversion is performed by the specified radix, and the
pointer to the converted character string will be returned.
radix must be a value in the range of 2 to 36. In other cases, the conversion is not performed and a null
pointer is returned.
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memcpy,
Character String/Memory Functions
memmove
FUNCTION
The memory function memcpy copies a specified number of characters from a source area of memory to a
destination area of memory.
The memory function memmove is identical to memcpy, except that it allows overlap between the source and
destination areas.
HEADER
string. h
FUNCTION PROTOTYPE
void *memcpy (void *s1, const void *s2, size_t n);
void *memmove (void *s1, const void *s2, size_t n);
Function
Arguments
Return Value
memcpy,
memmove
s1 ... Pointer to object into
which data is to be copied
s2 ... Pointer to object
containing data to be copied
n ... Number of characters to
be copied
Value of s1
EXPLANATION
memcpy
The memcpy function copies n number of consecutive bytes from the object pointed to by s2 to the object
pointed to by s1.
If s2 < s1 < s2+n (s1 and s2 overlap), the memory copy operation by memcpy is not guaranteed (because
copying starts in sequence from the beginning of the area).
memmove
The memmove function also copies n number of consecutive bytes from the object pointed to by s2 to the
object pointed to by s1.
Even if s1 and s2 overlap, the function performs memory copying properly.
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strcpy,
Character String/Memory Functions
strncpy
FUNCTION
The string function strcpy is used to copy the contents of one character string to another.
The string function strncpy is used to copy up to a specified number of characters from one character string to
another.
HEADER
string. h
FUNCTION PROTOTYPE
char *strcpy (char *s1, const char *s2);
char *strncpy (char *s1, const char *s2, size_t n);
Function
Arguments
Return Value
strcpy,
strncpy
s1... Pointer to copy
destination array
s2 ... Pointer to copy source
array
n ... Number of characters to
be copied
Value of s1
EXPLANATION
strcpy
The strcpy function copies the contents of the character string pointed to by s2 to the array pointed to by s1
(including the terminating character).
If s2 < s1
(s2 + Character length to be copied), the behavior of strcpy is not guaranteed (as copying starts
in sequence from the beginning, not from the specified string).
strncpy
The strncpy function copies up to the characters specified by n from the string pointed to by s2 to the array
pointed to by s1.
If s2 < s1
(s2 + Character length to be copied or minimum value of s2 + n 1), the behavior of strncpy is
not guaranteed (as copying starts in sequence from the beginning, not from the specified string).
If the string pointed by s2 is less than the characters specified by n, nulls will be appended to the end of s1
until n characters have been copied. If the string pointed to by s2 is longer than n characters, the resultant
string that is pointed to by s1 will not be null terminated.
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strcat,
Character String/Memory Functions
strncat
FUNCTION
The string function strcat concatenates one character string to another.
The string function strncat concatenates up to a specified number of characters from one character string to
another.
HEADER
string. h
FUNCTION PROTOTYPE
char *strcat (char *s1, const char *s2);
char *strncat (char *s1, const char *s2, size_t n);
Function
Arguments
Return Value
strcat,
strncat
s1... Pointer to a string to
which a copy of another string
(s2) is to be concatenated
s2 ... Pointer to a string, copy
of which is to be concatenated
to another string (s1).
n ... Number of characters to
be concatenated
Value of s1
EXPLANATION
strcat
The strcat function concatenates a copy of the string pointed to by s2 (including the null terminator) to the
string pointed to by s1. The null terminator originally ending s1 is overwritten by the first character of s2.
When copying is performed between objects overlapping each other, the operation is not guaranteed.
strncat
The strncat function concatenates not more than the characters specified by n of the string pointed to by s2
(excluding the null terminator) to the string pointed to by s1. The null terminator originally ending s1 is
overwritten by the first character of s2.
s1 must always be terminated with a null.
When copying is performed between objects overlapping each other, the operation is not guaranteed.
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memcmp
Character String/Memory Functions
FUNCTION
The memory function memcmp compares two data objects, with respect to a given number of characters.
HEADER
string. h
FUNCTION PROTOTYPE
int memcmp (const void *s1, const void *s2, size_t n);
Function
Arguments
Return Value
memcmp
s1, s2 ... Pointers to two data
objects to be compared
n ... Number of characters to
compare
0 if s1 and s2 are equal
Positive value if s1 is
greater than s2; negative
value if s1 is less than s2
(s1 s2)
EXPLANATION
The memcmp function compares the data object pointed to by s1 with the data object pointed to by s2 with
respect to the number of bytes specified by n.
If the two objects are equal, the function returns 0.
The function returns a positive value if the object s1 is greater than the object s2 and a negative value if s1 is
less than s2.
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strcmp,
Character String/Memory Functions
strncmp
FUNCTION
The string function strcmp compares two character strings.
The string function strncmp compares not more than a specified number of characters from two character
strings.
HEADER
string. h
FUNCTION PROTOTYPE
char *strcmp (char *s1, const char *s2);
char *strncmp (char *s1, const char *s2, size_t n);
Function
Arguments
Return Value
strcmp
s1... Pointer to one string to
be compared
s2 ... Pointer to the other
string to be compared
0 if s1 is equal to s2
Integer less than 0 or
greater than 0 if s1 is less
than or greater than s2 (s1
s2)
strncmp
s1... Pointer to one string to
be compared
s2 ... Pointer to the other
string to be compared
n ... Number of characters to
be compared
0 if s1 is equal to s2 within
characters specified by n
Integer less than 0 or
greater than 0 if s1 is less
than or greater than s2 (s1
s2) within characters
specified by n
EXPLANATION
strcmp
The strcmp function compares the two null terminated strings pointed to by s1 and s2, respectively.
If s1 is equal to s2, the function returns 0. If s1 is less than or grater than s2, the function returns an integer
less than 0 (a negative number) or greater than 0 (a positive number) (s1 s2).
strncmp
The strncmp function compares not more than the characters specified by n from the two null terminated
strings pointed to by s1 and s2, respectively.
If s1 is equal to s2 within the specified characters, the function returns 0. If s1 is less than or greater than s2
within the specified characters, the function returns an integer less than 0 (a negative number) or greater than
0 (a positive number) (s1 s2).
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memchr
Character String/Memory Functions
FUNCTION
The memory function memchr converts a specified character to unsigned char, searches for it, and returns a
pointer to the first occurrence of this character in an object of a given size.
HEADER
string. h
FUNCTION PROTOTYPE
void *memchr (const void *s, int c, size_t n);
Function
Arguments
Return Value
memchr
s ... Pointer to objects in
memory subject to search
c ... Character to be searched
n ... Number of bytes to be
searched
Pointer to the first
occurrence of c if c is found
Null pointer if c is not found
EXPLANATION
The memchr function first converts the character specified by c to unsigned char and then returns a pointer
to the first occurrence of this character within the n number of bytes from the beginning of the object pointed
to by s.
If the character is not found, the function returns a null pointer.
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strchr,
Character String/Memory Functions
strrchr
FUNCTION
The string function strchr returns a pointer to the first occurrence of a specified character in a string.
The string function strrchr returns a pointer to the last occurrence of a specified character in a string.
HEADER
string. h
FUNCTION PROTOTYPE
char *strchr (const char *s, int c);
char *strrchr (const char *s, int c);
Function
Arguments
Return Value
strchr,
strrchr
s... Pointer to string to be
searched
c ... Character specified for
search
Pointer indicating the first or
last occurrence of c in string
s if c is found in s
Null pointer if c is not found
in s
EXPLANATION
strchr
The strchr function searches the string pointed to by s for the character specified by c and returns a pointer
to the first occurrence of c (converted to char type) in the string.
The null terminator is regarded as part of the string.
If the specified character is not found in the string, the function returns a null pointer.
strrchr
The strrchr function searches the string pointed to by s for the character specified by c and returns a pointer
to the last occurrence of c (converted to char type) in the string.
The null terminator is regarded as part of the string.
If no match is found, the function returns a null pointer.
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strspn,
Character String/Memory Functions
strcspn
FUNCTION
The string function strspn returns the length of the initial substring of a string that is made up of only those
characters contained in another string.
The string function strcspn returns the length of the initial substring of a string that is made up of only those
characters not contained in another string.
HEADER
string. h
FUNCTION PROTOTYPE
size_t strspn (const char *s1, const char *s2);
size_t strcspn (const char *s1, const char *2);
Function
Arguments
Return Value
strspn
s1... Pointer to string to be
searched
s2 ... Pointer to string whose
characters are specified for
Length of substring of the
string s1 that is made up of
only those characters
contained in the string s2
strcspn
match
Length of substring of the
string s1 that is made up of
only those characters not
contained in the s2
EXPLANATION
strspn
The strspn function returns the length of the substring of the string pointed to by s1 that is made up of only
those characters contained in the string pointed to by s2. In other words, this function returns the index of the
first character in the string s1 that does not match any of the characters in the string s2.
The null terminator of s2 is not regarded as part of s2.
strcspn
The strcspn function returns the length of the substring of the string pointed to by s1 that is made up of only
those characters not contained in the string pointed to by s2. In other words, this function returns the index of
the first character in the string s1 that matches any of the characters in the string s2.
The null terminator of s2 is not regarded as part of s2.
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strpbrk
Character String/Memory Functions
FUNCTION
The string function strpbrk returns a pointer to the first character in a string to be searched that matches any
character in a specified string.
HEADER
string. h
FUNCTION PROTOTYPE
char *strpbrk (const char *s1, const char *s2);
Function
Arguments
Return Value
strpbrk
s1... Pointer to string to be
searched
s2 ... Pointer to string whose
characters are specified for
match
Pointer to the first character
in the string s1 that
matches any character in
the string s2 if any match is
found
Null pointer if no match is
found
EXPLANATION
The strpbrk function returns a pointer to the first character in the string pointed to by s1 that matches any
character in the string pointed to by s2.
If none of the characters in the string s2 is found in the string s1, the function returns a null pointer.
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strstr
Character String/Memory Functions
FUNCTION
The string function strstr returns a pointer to the first occurrence in the string to be searched of a specified
string.
HEADER
string. h
FUNCTION PROTOTYPE
char *strstr (const char *s1, const char *s2);
Function
Arguments
Return Value
strstr
s1... Pointer to string to be
searched
s2 ... Pointer to specified string
Pointer to the first
appearance in the string s1
of the string s2 if s2 is
found in s1
Null pointer if s2 is not
found in s1
Value of s1 if s2 is a null
string
EXPLANATION
The strstr function returns a pointer to the first appearance in the string pointed to by s1 of the string pointed
to by s2 (except the null terminator of s2).
If the string s2 is not found in the string s1, the function returns a null pointer.
If the string s2 is a null string, the function returns the value of s1.
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strtok
Character String/Memory Functions
FUNCTION
The string function strtok returns a pointer to a token taken from a string (by decomposing it into a string
consisting of characters other than delimiters).
HEADER
string. h
FUNCTION PROTOTYPE
char *strtok (char *s1, const char *s2);
Function
Arguments
Return Value
strtok
s1... Pointer to string from
which tokens are to be
obtained or null pointer
s2 ... Pointer to string
containing delimiters of token
Pointer to the first character
of a token if it is found
Null pointer if there is no
token to return
EXPLANATION
A token is a string consisting of characters other than delimiters in the string to be specified.
If s1 is a null pointer, the string pointed to by the saved pointer in the previous strtok call will be decomposed.
However, if the saved pointer is a null pointer, the function returns a null pointer without doing anything.
If s1 is not a null pointer, the string pointed to by s1 will be decomposed.
The strtok function searches the string pointed to by s1 for any character not contained in the string pointed
to by s2. If no character is found, the function changes the saved pointer to a null pointer and returns it. If
any character is found, the character becomes the first character of a token.
If the first character of a token is found, the function searches for any characters contained in the string s2
after the first character of the token. If none of the characters is found, the function changes the saved pointer
to a null pointer. If any of the characters is found, the character is overwritten by a null character and a
pointer to the next character becomes a pointer to be saved.
The function returns a pointer to the first character of the token.
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memset
Character String/Memory Functions
FUNCTION
The memory function memset initializes a specified number of bytes in an object in memory with a specified
character.
HEADER
string. h
FUNCTION PROTOTYPE
void *memset (void *s, int c, size_t n);
Function
Arguments
Return Value
memset
s ... Pointer to object in
memory to be initialized
c ... Character whose value is
to be assigned to each byte
n ... Number of bytes to be
initialized
Value of s
EXPLANATION
The memset function first converts the character specified by c to unsigned char and then assigns the value of
this character to the n number of bytes from the beginning of the object pointed to by s.
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strerror
Character String/Memory Functions
FUNCTION
The strerror function returns a pointer to the location which stores a string describing the error message
associated with a given error number.
HEADER
string. h
FUNCTION PROTOTYPE
char *strerror (int errnum);
Function
Arguments
Return Value
strerror
errnum ... Error number
Pointer to string describing
error message if message
associated with error
number exists
Null pointer if no message
associated with error
number exists
EXPLANATION
The strerror function returns a pointer to one of the following strings associated with the value of errnum
(error number):
0 .........................
"Error 0"
1 (EDOM) ...........
"Argument too large"
2 (ERANGE) .......
"Result too large"
3 (ENOMEM) ......
"Not enough memory"
Otherwise, the function returns a null pointer.
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strlen
Character String/Memory Functions
FUNCTION
The string function strlen returns the length of a character string.
HEADER
string. h
FUNCTION PROTOTYPE
size_t strlen (const char *s);
Function
Arguments
Return Value
strlen
s... Pointer to character string
Length of string s
EXPLANATION
The strlen function returns the length of the null terminated string pointed to by s.
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strcoll
Character String/Memory Functions
FUNCTION
strcoll compares two character strings based on the information specific to the locale.
HEADER
string.h
FUNCTION PROTOTYPE
int strcoll (const char *s1, const char *s2) ;
Function
Arguments
Return Value
strcoll
s1 ... Pointer to comparison
character string
s2 ... Pointer to comparison
character string
When character strings s1 and
s2 are equal ... 0
When character strings s1 and
s2 are different
... The difference between the
values whose first different
characters are converted to int
(character of s1 character of
s2)
EXPLANATION
This compiler does not support operations specific to a cultural sphere. The operations are the same as that
of strcmp.
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strxfrm
Character String/Memory Functions
FUNCTION
strxfrm converts a character string based on the information specific to the locale.
HEADER
string.h
FUNCTION
size_t strxfrm (char *s1, const char *s2, size_t n);
Function
Arguments
Return Value
strxfrm
s1 ... Pointer to a compared
character string
s2 ... Pointer to a compared
character string
n ... Maximum number of
characters to s1
Returns the length of the
character string of the result of
the conversion (does not
include a character string to
indicate the end)
If the returned value is n or
more, the contents of the
array indicated by s1 is
undefined.
EXPLANATION
This compiler does not support operations specific to a cultural sphere. The operations are the same as
those of the following functions.
strncpy (s1, s2, c) ;
return (strlen (s2)) ;
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acos
Mathematical Functions
FUNCTION
acos finds acos.
HEADER
math.h
FUNCTION PROTOTYPE
double acos (double x);
Function
Arguments
Return Value
acos
x ... Numeric value to perform
operation
When 1
x 1 ... acos of x
When x < 1, 1 < x, x = NaN
... NaN
EXPLANATION
Calculates acos of X (range between 0 and p).
When X is non-numeric, NaN is returned.
In the case of the definition area error of x < 1, 1 < x, NaN is returned and EDOM is set.
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asin
Mathematical Functions
FUNCTION
asin finds asin.
HEADER
math.h
FUNCTION PROTOTYPE
double asin (double x);
Function
Arguments
Return Value
asin
x ... Numeric value to perform
operation
When 1
x 1 ... asin of x
When x
1, 1 x, x = NaN
... NaN
When x = 0 ... 0
When underflow occurs ...
non-normalized number
EXPLANATION
Calculates asin (range between
/2 and +/2) of x.
In the case of area error of x < 1, 1 < x, NaN is returned and EDOM is set to errno.
When x is non-numeric, NaN is returned.
When x is 0, 0 is returned.
If an underflow occurs as a result of conversion, a non-normalized number is returned.
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atan
Mathematical Functions
FUNCTION
atan finds atan.
HEADER
math.h
FUNCTION PROTOTYPE
double atan (double x);
Function
Arguments
Return Value
atan
x ... numeric value to perform
operation
Normal ... atan of x
When x = NaN ... NaN
When x = 0 ... 0
EXPLANATION
Calculates atan (range between
/2 and +/2) of x.
When x is non-numeric, NaN is returned.
When x is 0, 0 is returned.
If an underflow occurs as a result of conversion, a non-normalized number is returned.
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atan2
Mathematical Functions
FUNCTION
atan2 finds atan of y/x.
HEADER
math.h
FUNCTION PROTOTYPE
double atan2 (double y, double x);
Function
Arguments
Return Value
atan2
x ... Numeric value to perform
operation
y ... Numeric value to perform
operation
Normal ... atan of y/x
When both x and y are 0 or
y/x is the value that cannot be
expressed, or either x or y is
NaN and both x and y are
... NaN
Non-normalized number ...
When underflow occurs
EXPLANATION
atan (range between
and +) of y/x is calculated. When both x and y are 0 or y/x is the value that cannot
be expressed, or when both x and y are infinite, NaN is returned and EDOM is set to errno.
If either x or y is non-numeric, NaN is returned.
If an underflow occurs as a result of the operation, a non-normalized number is returned.
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cos
Mathematical Functions
FUNCTION
cos finds cos.
HEADER
math.h
FUNCTION PROTOTYPE
double cos (double x);
Function
Arguments
Return Value
cos
x ... Numeric value to perform
operation
Normal ... cos of x
When x = NaN, x =
... NaN
EXPLANATION
Calculates cos of x.
If x is non-numeric, NaN is returned.
If x is infinite, NaN is returned and EDOM is set to errno.
If the absolute value of x is extremely large, the result of an operation becomes an almost meaningless value.
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sin
Mathematical Functions
FUNCTION
sin finds sin
HEADER
math.h
FUNCTION PROTOTYPE
double sin (double x);
Function
Arguments
Return Value
sin
x ... Numeric value to perform
operation
Normal ... sin of x
When x = NaN, x =
... NaN
When underflow occurs ...
Non-normalized number
EXPLANATION
Calculates sin of x.
If x is non-numeric, NaN is returned.
If x is infinite, NaN is returned and EDOM is set to errno.
If an underflow occurs as a result of the operation, a non-normalized number is returned.
If the absolute value of x is extremely large, the result of an operation becomes an almost meaningless value.
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7-7
tan
Mathematical Functions
FUNCTION
tan finds tan.
HEADER
math.h
FUNCTION PROTOTYPE
double tan (double x);
Function
Arguments
Return Value
tan
x ... Numeric value to perform
operation
Normal ... tan of x
When x = NaN, x =
... NaN
When underflow occurs ...
Non-normalized number
EXPLANATION
Calculates tan of x.
If x is non-numeric, NaN is returned.
If x is infinite, NaN is returned and EDOM is set to errno.
If an underflow occurs as a result of the operation, a non-normalized number is returned.
If the absolute value of x is extremely large, the result of an operation becomes an almost meaningless value.
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7-8
cosh
Mathematical Functions
FUNCTION
cosh finds cosh.
HEADER
math.h
FUNCTION PROTOTYPE
double cosh (double x) ;
Function
Arguments
Return Value
cosh
x ... Numeric value to perform
operation
Normal ... cosh of x
When overflow occurs, x =
NaN, x =
... HUGE_VAL
(with positive sign)
x = NaN ... NaN
EXPLANATION
Calculates cosh of x.
If x is non-numeric, NaN is returned.
If x is infinite, a positive infinite value is returned.
If an overflow occurs as a result of the operation, HUGE_VAL with a positive sign is returned, and ERANGE is
set to errno.
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7-9
sinh
Mathematical Functions
FUNCTION
sinh finds sinh.
HEADER
math.h
FUNCTION PROTOTYPE
double sinh (double x);
Function
Arguments
Return Value
sinh
x ... Numeric value to perform
operation
Normal ... sinh of x
When x = NaN ... NaN
When x =
...
When overflow occurs ...
HUGE_VAL (with the sign of
the overflowed value)
When underflow occurs ...
0
EXPLANATION
Calculates sinh of x.
If x is non-numeric, NaN is returned.
If x is
, is returned.
If an overflow occurs as a result of the operation, HUGE_VAL with the sign of the overflowed value is
returned, and ERANGE is set to errno.
If an underflow occurs as a result of the operation, 0 is returned.
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tanh
Mathematical Functions
FUNCTION
tanh finds tanh.
HEADER
math.h
FUNCTION PROTOTYPE
double tanh (double x);
Function
Arguments
Return Value
tanh
x ... Numeric value to perform
operation
Normal ... tanh of x
When x = NaN ... NaN
When x =
... 1
When underflow occurs ...
0
EXPLANATION
Calculates tanh of x.
If x is non-numeric, NaN is returned.
If x is
, 1 is returned.
If an underflow occurs as a result of the operation, 0 is returned.
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7-11
exp
Mathematical
FUNCTION
exp finds exponent function.
HEADER
math.h
FUNCTION PROTOTYPE
double exp (double x);
Function
Arguments
Return Value
exp
x ... Numeric value to perform
operation
Normal ... Exponent function of
x
When x = NaN ... NaN
When x =
...
When overflow occurs ...
HUGE_VQAL (with positive
sign)
When underflow occurs ...
Non-normalized number
When annihilation of valid
digits occurs due to underflow
... +0
EXPLANATION
Calculates the exponent function of x.
If x is non-numeric, NaN is returned.
If x is
, is returned.
If an underflow occurs as a result of the operation, a non-normalized number is returned.
If annihilation of valid digits due to underflow occurs as a result of the operation, +0 is returned.
If an overflow occurs as a result of the operation, HUGE_VAL with a positive sign is returned and ERANGE is
set to errno.
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frexp
Mathematical Functions
FUNCTION
frexp finds the mantissa and exponent part.
HEADER
math.h
FUNCTION PROTOTYPE
double frexp (double x, int *exp) ;
Function
Arguments
Return Value
frexp
x ... Numeric value to perform
operation
exp ... Pointer to store
exponent part
Normal ... Mantissa of x
When x = NaN, x =
... NaN
When x =
0 ... 0
EXPLANATION
Divides a floating-point number x into mantissa m and exponent n such as x = m*2^n and returns mantissa m.
Exponent n is stored where the pointer exp indicates. The absolute value of m, however, is 0.5 or more and
less than 1.0.
If x is non-numeric, NaN is returned and the value of *exp is 0.
If x is infinite, NaN is returned, and EDOM is set to errno with the value of *exp as 0.
If x is 0, 0 is returned and the value of *exp is 0.
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ldexp
Mathematical Functions
FUNCTION
ldexp finds x*2^exp.
HEADER
math.h
FUNCTION PROTOTYPE
double ldexp (double x, int exp);
Function
Arguments
Return Value
exp
x ... Numeric value to perform
operation
exp ... Exponentiation
Normal ... x*2 ^ exp
When x = NaN ... NaN
When x =
...
When x =
0 ... 0
When overflow occurs ...
HUGE_VAL (with the sign of
the overflowed value)
When underflow occurs ...
Non-normalized number
When annihilation of valid
digits occurs due to underflow
...
0
EXPLANATION
Calculates x*2^exp
If x is non-numeric, NaN is returned
If x is
, is returned.
If x is
0, 0 is returned.
If an overflow occurs as a result of the operation, HUGE_VAL with the overflowed value is returned and
ERANGE is set to errno.
If an underflow occurs as a result of the operation, a non-normalized number is returned.
If annihilation of valid digits due to underflow occurs as a result of the operation,
0 is returned.
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log
Mathematical Functions
FUNCTION
log finds the natural logarithm.
HEADER
math.h
FUNCTION PROTOTYPE
double log (double x);
Function
Arguments
Return Value
log
x ... Numeric value to perform
operation
Normal ... Natural logarithm of
x
When x
0 ... HUGE_VAL
(with negative sign)
When x is non-numeric ... NaN
When x is infinite ... +
EXPLANATION
Finds the natural logarithm of x.
If x is non-numeric, NaN is returned.
If x is +
, + is returned.
In the case of an area error of x < 0, HUGE_VAL with a negative sign is returned, EDOM is set to errno.
If x = 0, HUGE_VAL with a negative sign is returned, and ERANGE is set to errno.
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log10
Mathematical Functions
FUNCTION
log10 finds the logarithm with 10 as the base.
HEADER
math.h
FUNCTION PROTOTYPE
double log10 (double x) ;
Function
Arguments
Return Value
log10
x ... Numeric value to perform
operation
Normal ... Logarithm with 10 of
x as the base
When x
0 ... HUGE_VAL
(with negative sign)
When x is non-numeric ... NaN
When x is infinite ... +
EXPLANATION
Finds the logarithm with 10 of x as the base.
If x is non-numeric, NaN is returned.
If x is +
, + is returned.
In the case of an area error of x < 0, HUGE_VAL with a negative sign is returned, EDOM is set to errno.
If x = 0, HUGE_VAL with a negative sign is returned, and ERANGE is set to errno.
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modf
Mathematical Functions
FUNCTION
modf finds the fraction part and integer part.
HEADER
math.h
FUNCTION PROTOTYPE
double modif (double x, double *iptr);
Function
Arguments
Return Value
modif
x ... Numeric value to perform
operation
iptr ... Pointer to integer part
Normal ... Fraction part of x
When x is non-numeric or
infinite ... NaN
When x is
0 ... 0
EXPLANATION
Divides a floating-point number x into a fraction part and integer part
Returns the fraction part with the same sign as that of x, and stores the integer part in the location indicated
by the pointer iptr.
If x is non-numeric, NaN is returned and stored in the location indicated by the pointer iptr.
If x is infinite, NaN is returned and stored in the location indicated by the pointer iptr, and EDOM is set to
errno.
If x =
0, 0 is stored in the location indicated by the pointer iptr.
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pow
Mathematical Functions
FUNCTION
pow finds the yth power of x.
HEADER
math.h
FUNCTION PROTOTYPE
double pow (double x, double y);
Function
Arguments
Return Value
pow
x ... Numeric value to perform
operation
y ... Multiplier
Normal ... x^y
Either when x = NaN or y =
NaN,
x = +
and y = 0
x < 0 and y
integer,
x < 0 and y =
,
x = 0 and y < 0 ... NaN
When underflow occurs ...
Non-normalized number
When overflow occurs ...
HUGE_VAL (with the sign of
overflowed value)
When annihilation of valid
digits occurs due to underflow
...
0
EXPLANATION
Calculates x^y.
If an overflow occurs as a result of the operation, HUGE_VAL with the sign of overflown value is returned, and
ERANGE is set to errno.
When x = NaN or y = NaN, NaN is returned.
Either when x = +
and y = 0, x < 0 and y integer, x < 0 and y = or x = 0 and y 0, NaN is returned and
EDOM is set to errno.
If an underflow occurs, a non-normalized number is returned.
If annihilation of valid digits occurs due to underflow,
0 is returned.
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sqrt
Mathematical Functions
FUNCTION
sqrt finds the square root.
HEADER
math.h
FUNCTION PROTOTYPE
double sqrt (double x);
Function
Arguments
Return Value
sqrt
x ... Numeric value to perform
operation
When x
0 ... Square root of x
When x =
0 ... 0
When x < 0 ... NaN
EXPLANATION
Calculates the square root of x.
In the case of an area error of x < 0, 0 is returned and EDOM is set to errno.
If x is non-numeric, NaN is returned.
If x is 0, 0 is returned.
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ceil
Mathematical Function
FUNCTION
ceil finds the minimum integer no less than x.
HEADER
math.h
FUNCTION PROTOTYPE
double ceil (double x);
Function
Arguments
Return Value
ceil
x ... Numeric value to perform
operation
Normal ... The minimum
integer no less than x
When x is non-numeric or x =
... NaN
When x = 0 ... +0
When the minimum integer no
less than x cannot be
expressed ... x
EXPLANATION
Finds the minimum integer no less than x.
If x is non-numeric, NaN is returned.
If x is 0, +0 is returned.
If x is infinite, NaN is returned and EDOM is set to errno.
If the minimum integer no less than x cannot be expressed, x is returned.
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fabs
Mathematical Functions
FUNCTION
fabs returns the absolute value of the floating-point number x.
HEADER
math.h
FUNCTION PROTOTYPE
double fabs (double x) ;
Function
Arguments
Return Value
fabs
x ... Numeric value to find the
absolute value
Normal ... Absolute value of x
When x is non-numeric ... NaN
When x = 0 ... +0
EXPLANATION
Finds the absolute value of x.
If x is non-numeric, NaN is returned.
If x is 0, +0 is returned.
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floor
Mathematical Functions
FUNCTION
floor finds the maximum integer no more than x.
HEADER
math.h
FUNCTION PROTOTYPE
double floor (double x);
Function
Arguments
Return Value
floor
x ... Numeric value to perform
operation
Normal ... The maximum
integer no more than x
When x is non-numeric or x =
... NaN
When x = 0 ... +0
When the maximum integer no
more than x cannot be
expressed
EXPLANATION
Finds the maximum integer no more than x.
If x is non-numeric, NaN is returned.
If x is 0, +0 is returned.
If x is infinite, NaN is returned and EDOM is set to errno.
If the maximum integer no more than x cannot be expressed, x is returned.
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fmod
Mathematical Functions
FUNCTION
fmod finds the remainder of x/y.
HEADER
math.h
FUNCTION PROTOTYPE
double fmod (double x, double y);
Function
Arguments
Return Value
fmod
x ... Numeric value to perform
operation
y ... Numeric value to perform
operation
Normal ... Remainder of x/y
When x is non-numeric or y is
non-numeric, when y is
0,
when x is
... NaN
When x
and y = ... x
EXPLANATION
Calculates the remainder of x/y expressed with x i*y. i is an integer.
If y
0, the return value has the same sign as that of x and the absolute value is less than that of y.
If y is
0 or x = , NaN is returned and EDOM is set to errno.
If x is non-numeric or y is non-numeric, NaN is returned.
If y is infinite, x is returned unless x is infinite.
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matherr
Mathematical Functions
FUNCTION
matherr performs exception processing of the library that deals with floating-point numbers.
HEADER
math.h
FUNCTION PROTOTYPE
void matherr (struct exception *x) ;
Function
Arguments
Return Value
matherr
struct exception {
int type;
char *name;
}
type ..... numeric value to
indicate
arithmetic exception
name ... function name
None
EXPLANATION
When an exception is generated, matherr is automatically called in the standard and runtime libraries that
deal with floating-point numbers.
When called from the standard library, EDOM and ERANGE are set to errno.
The following shows the relationship between the arithmetic exception type and errno.
Type
Arithmetic Exception
Value Set to errno
1
2
3
4
5
Underflow
Annihilation
Overflow
Zero division
Inoperable
ERANGE
ERANGE
ERANGE
EDOM
EDOM
Original error processing can be performed by changing or creating matherr.
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7-24
acosf
Mathematical Functions
FUNCTION
acosf finds acos.
HEADER
math.h
FUNCTION PROTOTYPE
float acosf (float x);
Function
Arguments
Return Value
acosf
x ... Numeric value to perform
operation
When 1
x 1 ... acos of x
When x
1, 1 < x, x = ...
NaN
EXPLANATION
Calculates acos (range between 0 and
) of x
If x is non-numeric, NaN is returned.
In the case of a definition area error of x
1, 1 x, NaN is returned and EDOM is set to errno.
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asinf
Mathematical Functions
FUNCTION
asinf finds asin.
HEADER
math.h
FUNCTION PROTOTYPE
float asinf (float x);
Function
Arguments
Return Value
asinf
x ... Numeric value to perform
operation
When 1
x 1 ... asin of x
When x
1, 1 < x, x = NaN
... NaN
x = 0 ... 0
When underflow occurs ...
Non-normalized number
EXPLANATION
Calculates asin (range between
/2 and +/2) of x
If x is non-numeric, NaN is returned.
In the case of definition area error of x
1, 1 x, NaN is returned and EDOM is set to errno.
If x = 0, 0 is returned.
If an underflow occurs as a result of the operation, a non-normalized number is returned.
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atanf
Mathematical Functions
FUNCTION
atanf finds atan.
HEADER
math.h
FUNCTION PROTOTYPE
float atanf (float x);
Function
Arguments
Return Value
atanf
x ... Numeric value to perform
operation
Normal ... atan of x
When x = NaN ... NaN
When x = 0 ... 0
EXPLANATION
Calculates atan (range between
/2 and +/2) of x
If x is non-numeric, NaN is returned.
If x = 0, 0 is returned.
If an underflow occurs as a result of the operation, a non-normalized number is returned.
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atan2f
Mathematical Functions
FUNCTION
atan2f finds atan of y/x.
HEADER
math.h
FUNCTION PROTOTYPE
float atan2f (float y, float x);
Function
Arguments
Return Value
atan2f
x ... Numeric value to perform
operation
y ... Numeric value to perform
operation
Normal ... atan of y/x
When both x and y are 0 or a
value whose y/x cannot be
expressed, or either x or y is
NaN, both x and y are
...
NaN
When underflow occurs ...
Non-normalized number
EXPLANATION
Calculates atan (range between
and +) of y/x. When both x and y are 0 or the value whose y/x cannot
be expressed, or when both x and y are infinite, NaN is returned and EDOM is set to errno.
When either x or y is non-numeric, NaN is returned.
If an underflow occurs as a result of the operation, a non-normalized number is returned.
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cosf
Mathematical Functions
FUNCTION
cosf finds cos.
HEADER
math.h
FUNCTION PROTOTYPE
float cost (float x);
Function
Arguments
Return Value
cosf
x ... Numeric value to perform
operation
Normal ... cos of x
When x = NaN, x =
... NaN
EXPLANATION
Calculates cos of x.
If x is non-numeric, NaN is returned.
If x is infinite, NaN is returned and EDOM is set to errno.
If the absolute value of x is extremely large, the result of an operation becomes an almost meaningless value.
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sinf
Mathematical Functions
FUNCTION
sinf finds sin.
HEADER
math.h
FUNCTION PROTOTYPE
float sinf (float x);
Function
Arguments
Return Value
sinf
x ... Numeric value to perform
operation
Normal ... sin of x
When x = NaN, x =
... NaN
When underflow occurs ...
Non-normalized number
EXPLANATION
Calculates sin of x.
If x is non-numeric, NaN is returned.
If x is infinite, NaN is returned and EDOM is set to errno.
If an underflow occurs as a result of the operation, a non-normalized number is returned.
If the absolute value of x is extremely large, the result of an operation becomes an almost meaningless value.
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tanf
Mathematical Functions
FUNCTION
tanf finds tan.
HEADER
math.h
FUNCTION PROTOTYPE
float tanf (float x);
Function
Arguments
Return Value
tanf
x ... Numeric value to perform
operation
Normal ... tan of x
When x = NaN, x =
... NaN
When underflow occurs ...
Non-normalized number
EXPLANATION
Calculates tan of x.
If x is non-numeric, NaN is returned.
If x is infinite, NaN is returned and EDOM is set to errno.
If an underflow occurs as a result of the operation, a non-normalized number is returned.
If the absolute value of x is extremely large, the result of an operation becomes an almost meaningless value.
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coshf
Mathematical Functions
FUNCTION
coshf finds cosh.
HEADER
math.h
FUNCTION PROTOTYPE
float coshf (float x) ;
Function
Arguments
Return Value
coshf
x ... Numeric value to perform
operation
Normal ... cosh of x
When overflow occurs, x =
... HUGE_VAL (with a positive
sign)
x = NaN ... NaN
EXPLANATION
Calculates cosh of x.
If x is non-numeric, NaN is returned.
If x is infinite, positive infinite value is returned.
If an overflow occurs as a result of the operation, HUGE_VAL with a positive sign is returned and ERANGE is
set to errno.
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sinhf
Mathematical Functions
FUNCTION
sinhf finds sinh.
HEADER
math.h
FUNCTION PROTOTYPE
float sinhf (float x);
Function
Arguments
Return Value
sinhf
x ... Numeric value to perform
operation
Normal ... sinh of x
When overflow occurs ...
HUGE_VAL (with a sign of the
overflowed value)
x = NaN ... NaN
When x =
...
When underflow occurs ...
0
EXPLANATION
Calculates sinh of x.
If x is non-numeric, NaN is returned.
If x is
, is returned.
If an overflow occurs as a result of the operation, HUGE_VAL with the sign of overflowed value is returned
and ERANGE is set to errno.
If an underflow occurs as a result of the operation,
0 is returned.
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tanhf
Mathematical Functions
FUNCTION
tanhf finds tanh.
HEADER
math.h
FUNCTION PROTOTYPE
float tanhf (float x);
Function
Arguments
Return Value
tanhf
x ... Numeric value to perform
operation
Normal ... tanh of x
x = NaN ... NaN
When x =
... 1
When underflow occurs ...
0
EXPLANATION
Calculates tanh of x.
If x is non-numeric, NaN is returned.
If x is
, 1 is returned.
If an underflow occurs as a result of the operation, 0 is returned.
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expf
Mathematical Functions
FUNCTION
expf finds the exponent function.
HEADER
math.h
FUNCTION PROTOTYPE
float expf (float x);
Function
Arguments
Return Value
expf
x ... Numeric value to perform
operation
Normal ... Exponent function of
x
When overflow occurs ...
HUGE_VAL (with positive sign)
x = NaN ... NaN
When x =
...
When underflow occurs ...
Non-normalized number
When annihilation of valid
digits occurs due to underflow
... +0
EXPLANATION
Calculates exponent function of x.
If x is non-numeric, NaN is returned.
If x is
, is returned.
If an overflow occurs as a result of the operation, HUGE_VAL with a positive sign is returned and ERANGE is
set to errno.
If an underflow occurs as a result of the operation, a non-normalized number is returned.
If annihilation of effective digits occurs due to underflow as a result of the operation, +0 is returned.
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frexpf
Mathematical Functions
FUNCTION
frexpf finds the mantissa and exponent part.
HEADER
math.h
FUNCTION PROTOTYPE
float frexpf (float x, int *exp) ;
Function
Arguments
Return Value
frexpf
x ... Numeric value to perform
operation
exp ... Pointer to store exponent
part
Normal ... Mantissa of x
When x = NaN, x =
... NaN
When x =
0 ... 0
EXPLANATION
Divides a floating-point number x into mantissa m and exponent n such as x = m*2^n and returns mantissa
m.
Exponent n is stored in where the pointer exp indicates. The absolute value of m, however, is 0.5 or more
and less than 1.0.
If x is non-numeric, NaN is returned and the value of *exp is 0.
If x is
, NaN is returned, and EDOM is set to errno with the value of *exp as 0.
If x is
0, 0 is returned and the value of *exp is 0.
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ldexpf
Mathematical Functions
FUNCTION
ldexpf finds x*2^exp.
HEADER
math.h
FUNCTION PROTOTYPE
float ldexpf (float x, int exp);
Function
Arguments
Return Value
ldexpf
x ... Numeric value to perform
operation
exp ... Exponentiation
Normal ... x*2^exp
When x = NaN ... NaN
When x =
...
When x =
0 ... 0
When overflow occurs ...
HUGE=VAL (with the sign of
overflowed value)
When underflow occurs ...
Non-normalized numberV
When annihilation of valid
digits occurs due to underflow
...
0
EXPLANATION
Calculates x*2^exp.
If x is non-numeric, NaN is returned. If x is
, is returned. If x is 0, 0 is returned.
If overflow occurs as a result of operation, HUGE_VAL with the sign of overflowed value is returned and
ERANGE is set to errno.
If an underflow occurs as a result of the operation, a non-normalized number is returned.
If annihilation of valid digits due to underflow occurs as a result of the operation,
0 is returned.
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logf
Mathematical Functions
FUNCTION
logf finds the natural logarithm.
HEADER
math.h
FUNCTION PROTOTYPE
float logf (float x);
Function
Arguments
Return Value
logf
x ... Numeric value to perform
operation
Normal ... Natural logarithm of x
When x is non-numeric ... NaN
When x is infinite ... +
When x
0 ... HUGE_VAL
(with negative sign)
EXPLANATION
Finds natural logarithm of x.
If x is non-numeric, NaN is returned.
If x is +
, + is returned.
In the case of an area error of x < 0, HUGE_VAL with a negative sign is returned, and EDOM is set to errno.
If x = 0, HUGE_VAL with a negative sign is returned, and ERANGE is set to errno.
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log10f
Mathematical Functions
FUNCTION
log10f finds the logarithm with 10 as the base.
HEADER
math.h
FUNCTION PROTOTYPE
float log10f (float x);
Function
Arguments
Return Value
log10f
x ... Numeric value to perform
operation
Normal ... Logarithm with 10 of
x as the base
When x is non-numeric ... NaN
When x = +
... +
When x
0 ... HUGE_VAL
(with negative sign)
EXPLANATION
Finds the logarithm with 10 of x as the base.
If x is non-numeric, NaN is returned.
If x is +
, + is returned.
In the case of an area error of x < 0, HUGE_VAL with a negative sign is returned, and EDOM is set to errno.
If x = 0, HUGE_VAL with a negative sign is returned, and ERANGE is set to errno.
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modff
Mathematical Functions
FUNCTION
modff finds the fraction part and integer part.
HEADER
math.h
FUNCTION PROTOTYPE
float modff (float x, float *iptr);
Function
Arguments
Return Value
modff
x ... Numeric value to perform
operation
iptr ... Pointer for integer part
Normal ... Fraction part of x
When x is non-numeric or
infinite ... NaN
When x =
0 ... 0
EXPLANATION
Divides a floating-point number x into a fraction part and integer part.
Returns the fraction part with the same sign as that of x, and stores the integer part in the location indicated
by the pointer iptr.
If x is non-numeric, NaN is returned and stored in the location indicated by the pointer iptr.
If x is infinite, NaN is returned and stored in the location indicated by the pointer iptr, and EDOM is set to
errno.
If x =
0, 0 is returned and stored in the location indicated by the pointer iptr.
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powf
Mathematical Functions
FUNCTION
powf finds the yth power of x.
HEADER
math.h
FUNCTION PROTOTYPE
float powf (float x, float y);
Function
Arguments
Return Value
powf
x ... Numeric value to perform
operation
y ... Multiplier
Normal ... x^y
Either when =
x = NaN or y = NaN
x = +
and y = 0
x < 0 and y
integer,
x < 0 and y =
x = 0 and y
0 ... NaN
When underflow occurs ...
Non-normalized number
When overflow occurs ...
HUGE_VAL (with the sign of
overflowed value)
When annihilation of valid
digits occurs due to underflow
...
0
EXPLANATION
Calculates x^y.
If an overflow occurs as a result of the operation, HUGE_VAL with the sign of overflowed value is returned,
and ERANGE is set to errno.
When x = NaN or y = NaN, NaN is returned.
Either when x = +
and y = 0, x < 0 and y integer, x < 0 and y = , or x = 0 and y 0, NaN is returned and
EDOM is set to errno.
If an underflow occurs, a non-normalized number is returned.
If annihilation of valid digits occurs due to underflow,
0 is returned.
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sqrtf
Mathematical Functions
FUNCTION
sqrtf finds the square root.
HEADER
math.h
FUNCTION PROTOTYPE
float sqrtf (float x);
Function
Arguments
Return Value
sqrtf
x ... Numeric value to perform
operation
When x
0 ... Square root of x
When x =
0 ... 0
When x < 0 ... NaN
EXPLANATION
Calculates the square root of x.
In the case of area error of x < 0, 0 is returned and EDOM is set to errno.
If x is non-numeric, NaN is returned.
If x is
0, 0 is returned.
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ceilf
Mathematical Functions
FUNCTION
ceilf finds the minimum integer no less than x.
HEADER
math.h
FUNCTION PROTOTYPE
float ceilf (float x);
Function
Arguments
Return Value
ceilf
x ... Numeric value to perform
operation
Normal ... The minimum
integer no less than x
When x is non-numeric or x =
... NaN
When x = 0 ... +0
When the minimum integer no
less than x cannot be
expressed ... x
EXPLANATION
Finds the minimum integer no less than x.
If x is non-numeric, NaN is returned.
If x is 0, +0 is returned.
If x is infinite, NaN is returned and EDOM is set to errno.
If the minimum integer no less than x cannot be expressed, x is returned.
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fabsf
Mathematical Functions
FUNCTION
fabsf returns the absolute value of the floating-point number x.
HEADER
math.h
FUNCTION PROTOTYPE
float fabsf (float x);
Function
Arguments
Return Value
fabsf
x ... Numeric value to find the
absolute value
Normal ... Absolute value of x
When x is non-numeric ... NaN
When x = 0 ... +0
EXPLANATION
Finds the absolute value of x.
If x is non-numeric, NaN is returned.
If x is 0, +0 is returned.
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floorf
Mathematical Functions
FUNCTION
floorf finds the maximum integer no more than x.
HEADER
math.h
FUNCTION PROTOTYPE
float floorf (float x);
Function
Arguments
Return Value
floorf
x ... Numeric value to perform
operation
Normal ... The maximum
integer no more than x
When x is non-numeric or
infinite ... NaN
When x = 0 ... +0
When the maximum integer no
more than x cannot be
expressed ... x
EXPLANATION
Finds the maximum integer no more than x.
If x is non-numeric, NaN is returned.
If x is 0, +0 is returned.
If x is infinite, NaN is returned and EDOM is set to errno.
If the maximum integer no more than x cannot be expressed, x is returned.
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fmodf
Mathematical Functions
FUNCTION
fmodf finds the remainder of x/y.
HEADER
math.h
FUNCTION PROTOTYPE
float fmodf (float x, float y);
Function
Arguments
Return Value
fmodf
x ... Numeric value to perform
operation
y ... Numeric value to perform
operation
Normal ... Remainder of x/y
When x is non-numeric or y is
non-numeric
When y is
0, when x is ...
NaN
When x
and y = ... x
EXPLANATION
Calculates the remainder of x/y expressed with x i*y. i is an integer.
If y
0, the return value has the same sign as that of x and the absolute value is less than y.
If y is
0 or x = , NaN is returned and EDOM is set to errno.
If x is non-numeric or y is non-numeric, NaN is returned.
If y is infinite, x is returned unless x is infinite.
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8-1
_ _ assertfail
Diagnostic Functions
FUNCTION
_ _ assertfail supports the assert macro.
HEADER
math.h
FUNCTION PROTOTYPE
int _ _assertfail (char*_ _msg, char*_ _cond, char*_ _file, int_ _line);
Function
Arguments
Return Value
_ _assertfail
_ _msg ... Pointer to character
string to indicate output
conversion specification to be
passed to printf function
_ _cond ... Actual argument of
assert macro
_ _file ... Source file name
_ _line ... Source line number
Undefined
EXPLANATION
The _ _ assertfail function receives information from the assert macro (refer to 10.2 Headers (13) assert.h),
calls the printf function, outputs information, and calls the abort function.
The assert macro adds diagnostic functions to a program. When an assert macro is executed, if p is false
(equal to 0), an assert macro passes information related to the specific call that has brought the false value
(actual argument text, source file name, and source line number are included in the information. The other two
are the values of macro_FILE_ _ and _ _LINE_ _, respectively) to the _ _assertfail function.
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10.5 Batch Files for Update of Startup Routine and Library Functions
This compiler is provided with batch files for updating a part of the standard library functions and the startup
routine. The batch files in the BAT directory are shown in Table 10-3 below.
Caution
The file d4025.78k in the BAT directory is used during batch file activation for updating the
library, not for development. When developing a system, it is necessary to have a device file
(sold separately).
Table 10-3. Batch Files for Updating Library Functions
Batch File
Application
mkstup.bat
Updates the startup routine (cstart*.asm).
When changing the startup routine, perform assembly using this batch file.
reprom.bat
Updates the firmware ROM termination routine (rom.asm).
When changing rom.asm, update the library using this batch file.
repgetc.bat
Updates the getchar function.
The default assumption sets P0 of the SFR to input port. When it is necessary to change this setting, change
the defined value of EQU of PORT in getchar.asm and update the library using this batch file.
repputc.bat
Updates the putchar function.
The default assumption sets P0 of the SFR to output port. When it is necessary to change this setting, change
the defined value of EQU of PORT in putchar.asm and update the library using this batch file.
repputcs.bat
Updates the putchar function to SM78K4-supporting.
When it is necessary to check the output of the putchar function using the SM78K4, update the library using
this batch file.
repselo.bat
Saves/restores the reserved area of the compiler (_@KREGxx) as part of the save/restore processing of the
setjmp/longjmp functions (the default assumption is to not save/restore).
Update the library using this batch file when the -QR option is specified.
repselon.bat
Does not save/restore the reserved area of the compiler (_@KREGxx) as part of the save/restore processing
of the setjmp/longjmp functions (the default assumption is to not save/restore).
Update the library using this batch file when the -QR option is not specified.
repvect.bat
Updates the address value setting processing of the branch table of the interrupt vector table allocated in the
flash area (vect*.asm).
The default assumption sets the top address of the flash area branch table to 4000H. When it is necessary to
change this setting, change the defined value of EQU of ITBLTOP in vect.inc and update the library using this
batch file.
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10.5.1 Using batch files
Use the batch files in the subdirectory BAT. Because these files are the batch files used to activate the assembler
and librarian, an environment in which the assembler package RA78K4 Ver. 1.50 or later operates is necessary.
Before using the batch files, set the directory that contains the RA78K4 execution format file using the
environment variable PATH.
Create a subdirectory (LIB) of the same level as BAT for the batch files and put the post-assembly files in this
subdirectory.
When a C startup routine or library is installed in a subdirectory LIB that is the same level as BAT, these files are
overwritten.
To use the batch files, move the current directory to the subdirectory BAT and execute each batch file. At this
time, the following parameters are necessary.
Product type = chiptype (classification of target chip)
4026
PD784026, etc.
The following is an illustration of how to use each batch file.
The batch file for:
(1) Startup routine
For PC-9800 series, IBM PC/AT
TM
and compatibles
mkstup chiptype
Example mkstup 4026
For HP9000 series 700TM, SPARCstationTM Family
/bin/sh mkstup.sh chiptype
Example /bin/sh mkstup.sh 4026
(2) Firmware ROM routine update
For PC-9800 series, IBM PC/AT and compatibles
reprom chiptype
Example reprom 4026
For HP9000 series 700, SPARCstation Family
/bin/sh reprom.sh chiptype
Example /bin/sh reprom.sh 4026
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(3) getchar function update
For PC-9800 series, IBM PC/AT and compatibles
repgetc chiptype
Example repgetc 4026
For HP9000 series 700, SPARCstation Family
/bin/sh repgetc.sh chiptype
Example /bin/sh repgetc.sh 4026
(4) putchar function update
For PC-9800 series, IBM PC/AT and compatibles
repputc chiptype
Example repputc 4026
For HP9000 series 700, SPARCstation Family
/bin/sh repputc.sh chiptype
Example /bin/sh repputc.sh 4026
(5) putchar function (SM78K4-supporting) update
For PC-9800 series, IBM PC/AT and compatibles
repputcs chiptype
Example repputcs 4026
For HP9000 series 700, SPARCstation Family
/bin/sh repputcs.sh chiptype
Example /bin/sh repputcs.sh 4026
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(6) setjmp/longjmp function update (with restore/save processing)
For PC-9800 series, IBM PC/AT and compatibles
repselo chiptype
Example repselo 4026
For HP9000 series 700, SPARCstation Family
/bin/sh repselo.sh chiptype
Example /bin/sh repselo.sh 4026
(7) setjmp/longjmp function update (without restore/save processing)
For PC-9800 series, IBM PC/AT and compatibles
repselon chiptype
Example repselon 4026
For HP9000 series 700, SPARCstation Family
/bin/sh repselon.sh chiptype
Example /bin/sh repselon.sh 4026
(8) Interrupt vector table update
For PC-9800 series, IBM PC/AT and compatibles
repvect chiptype
Example repvect 4026
For HP9000 series 700, SPARCstation Family
/bin/sh repvect.sh chiptype
Example /bin/sh repvect.sh 4026
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CHAPTER 11 EXTENDED FUNCTIONS
This chapter describes the extended functions unique to this C compiler and not specified in the ANSI (American
National Standards Institute) Standard for C.
The extended functions of this C compiler are used to generate codes for effective utilization of the target devices
in the 78K/IV Series. Not all of these extended functions are always effective. Therefore, it is recommended to use
only the effective ones according to the purpose of use. For the effective use of the extended functions, refer to
CHAPTER 13 EFFECTIVE UTILIZATION OF COMPILER along with this chapter.
C source programs created by using the extended functions of the C compiler utilize microcontroller-dependent
functions. As regards portability to other microcontrollers, they are compatible at the C language level. For this
reason, C source programs developed by using these extended functions are portable to other microcontrollers with
easy-to-make modifications.
Remark
In the explanation of this chapter, "RTOS" indicates the 78K/IV Series real-time OS.
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11.1 Macro Names
This C compiler has two types of macro names: those indicating the series name for target devices and those
indicating device name (processor type). These macro names are specified according to the option for compilation to
output object code for a specific target device or according to the processor type in the C source. In the example
below, _ _K4_ _ and _ _4026_ are specified.
For details of these macro names, see 9.8 Compiler-Defined Macro Names.
[Example]
Option for compilation
>CC78K4 -C4026 prime.c ...
Specification of device type:
#pragma pc (4026)
11.2 Keywords
The following tokens are added to this C compiler as keywords to realize the extended functions. Similarly to
ANSI-C keywords, these tokens cannot be used as labels or as variable names. All the keywords must be described
in lowercase letters. A keyword containing an uppercase letter is not interpreted as a keyword by the C compiler.
This following shows the list of keywords added to this compiler. Of these keywords, ones not starting with "_ _"
can be disabled by specifying the option (-ZA) that enables only ANSI-C language specifications (for the ANSI-C
keywords, refer to 2.1 Keywords).
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Table 11-1. List of Added Keywords
Keyword
Use
_
_
_
_ ____callt
callt
callt/
_
_
_
_ ____callt functions
_
_
_
_ ____callf
callf
callf/
_
_
_
_ ____callf functions
_
_
_
_ ____sreg
sreg
sreg/
_
_
_
_ ____sreg variables
_
_
_
_ ____sreg1
_
_
_
_ ____sreg1 variables
noauto
noauto functions
_
_
_
_ ____leaf
norec
norec/
_
_
_
_ ____leaf functions
_
_
_
_ ____boolean
boolean
boolean type/
_ ____boolean type
bit
bit type variables
_
_
_
_ ____boolean1
_
_
_
_ ____boolean1 type variables
_
_
_
_ ____interrupt
Hardware interrupt
_
_
_
_ ____interrupt____brk
Software interrupt
_
_
_
_ ____asm
ASM statements
_
_
_
_ ____rtos____interrupt
Handler to allocate for RTOS
_
_
_
_ ____pascal
Pascal function
_
_
_
_ ____flash
Firmware ROM function
_
_
_
_ ____directmap
Absolute address allocation specification
(1) Functions
The keywords callt, _ _callt, callf _ _callf, noauto, norec, _ _leaf, _ _interrupt, _ _interrupt_brk,
_ _rtos_interrupt, and _ _flash are attribute qualifiers.
These keywords must be described before any function declaration. The format of each attribute qualifier is
shown below.
Attribute-qualifier ordinary-declarator function-name (parameter type list/identifier list)
_ _callt int func (int);
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Attribute qualifier specifications are limited to those listed below. (The noauto and norec/_ _leaf qualifiers
cannot be specified at the same time.) callt and _ _callt, callf and _ _callf, norec and _ _leaf are regarded as
the same specifications. However, qualifiers that include `_ _' are enabled even when the -ZA option is
specified.
callt
callf
noauto
norec
callt noauto
callt norec
noauto callt
norec callt
callf noauto
callf norec
noauto callf
norec callf
_ _interrupt
_ _interrupt_brk
_ _rtos_interrupt
_ _pascal
_ _pascal noauto
_ _pascal callt
_ _pascal callf
noauto_ _pascal
callt_ _pascal
callf_ _pascal
callt noauto_ _pascal
callf noauto_ _pascal
_ _flash
(2) Variables
The keyword sreg, _ _sreg, or _ _sreg1 is specified in a similar manner to the register storage class
specifier of C. (For details, see 11.5 (3) How to use the saddr area.)
The keyword bit, boolean, _ _boolean, or _ _boolean1 is specified in a similar manner to the char or int
type specifier of C.
However, these types can be specified only for the variables defined outside a function (external variables).
The same regulations apply to the _ _directmap specification as to the type qualifiers in C language (refer to
11.5 (42) Absolute address allocation specification for details).
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11.3 Memory
The memory model is determined by the memory space of the target device.
(1) Memory model
A maximum of 1 MB of program memory space and a maximum of 16 MB of data memory space are available
(for the memory map, refer to the user's manual of each target device).
This compiler has the three types of memory models: small, medium, and large. Objects are changed and output
by specifying each memory model option. For details of each model, refer to Table 11-2.
Table 11-2. Memory Model
Memory Model (Option)
Explanation
Small model (-MS)
A model with a combined code/data block capacity of 64
KB.
Medium model (-MM)
A model with a capacity of up to 1 MB for the code block
and 64 KB for the data block
Large model (-ML)
A model with a combined code/data block capacity of 16
MB, including up to 1 MB for the code block and 16 MB for
the data block.
(2) Register bank
The register bank is set to `RB0' at startup (set in the startup routine of this compiler). Register bank 0 is
made always used (unless the register bank is changed) by this setting.
The specified register bank is set at the start of the interrupt function that has specified the change of the
register bank.
(3) Location function
With the large model or medium model, the location function (-CS option) allows changing the location of the
internal RAM (including saddr area and sfr area) between 64 KB (LOCATION 00H) and 1024 KB (LOCATION
0FH) (with the small model, the location of the internal RAM is fixed to 64 KB). For the -CS option, refer to the
CC78K4 C Compiler Operation User's Manual (U15557E).
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(4) Memory space
This C compiler uses memory space as shown in Table 11-3 below.
Table 11-3. Utilization of Memory Space
Address
Use
Size (Bytes)
00
40 to 7FH
CALLT table
64
0800 to 0FFFH
CALLF entry
2048
(F)FD
20 to DFH
sreg variables, boolean type variables
192
(F)FD
20 to FFH
Arguments of norec functions
Note 1
8
Automatic variables of norec functions
Note 1
8
Register variables
Note 1
16
(F)FE
00 to 7FH
sreg1 variables, boolean1 type variables
128
(F)FE
80 to EFH
RB7 to RB1
Note 2
(work registers)
112
F0 to FFH
RB0 (work registers)
16
(F)FF
00 to FFH
sfr variables
256
Notes 1.
The restore to this area is not processed within the interrupt function when the -qr option is not
specified (default). This reduces the preprocessing/postprocessing of interrupt functions and allows
users to use the areas of Note 1 as sreg variable or boolean type variable areas when using a real-
time OS, etc. For the save/restore processing code output, refer to 11.5 (10) Interrupt function. This
area, as shown in APPENDIX A LIST OF LABELS FOR saddr AREA, defines labels and secures
areas in a library.
Standard library functions setjmp, longjmp refer to a part of this area _@KREG00.
2.
Used when a register bank is specified.
Consecutive 32-byte area in
the interval above
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11.4 #pragma directives
The #pragma directives are preprocessing directives supported by ANSI. A #pragma directive, depending on the
character string to follow #pragma, instructs the compiler to translate using the method determined by the compiler.
If the compiler does not support #pragma directives, the #pragma directive is ignored and compilation is continued.
If keywords are added by a directive, an error is output if the C source includes the keywords. In order to avoid this,
the keywords in the C source should either be deleted or sorted by the #ifdef directive.
This C compiler supports the following #pragma directives to realize the extended functions.
The keywords specified after #pragma can be described either in uppercase or lowercase letters.
For the extended functions using #pragma directives, refer to 11.5 How to Use Extended Functions.
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Table 11-4. List of #pragma Directives
#pragma Directive
Applications
#pragma sfr
Describes SFR name in C
11.5 (4) How to use the sfr area
#pragma asm
Inserts ASM statement in C source
11.5 (9) ASM statements
#pragma vect
#pragma interrupt
Describes interrupt processing in C
11.5 (10) Interrupt functions
#pragma di
#pragma ei
Describes DI/EI instructions in C
11.5 (12) Interrupt functions
#pragma halt
#pragma stop
#pragma nop
#pragma brk
Describes CPU control instructions in C
11.5 (13) CPU control instruction
#pragma access
Uses absolute address access functions
11.5 (17) Absolute address access function
#pragma section
Changes compiler output section name and specifies section location
11.5 (19) Changing compiler output section name
#pragma name
Changes module name
11.5 (21) Module name changing function
#pragma rot
Uses rotate function
11.5 (22) Rotate function
#pragma mul
Uses multiplication function
11.5 (23) Multiplication function
#pragma div
Uses division function
11.5 (24) Division function
#pragma opc
Uses data insertion function
11.5 (25) Data insertion function
#pragma rtos_interrupt
Uses interrupt handler for real-time OS (RX78K/IV)
11.5 (26) Interrupt handler for real-time OS (RTOS)
#pragma rtos_task
Uses task function for real-time OS (RX78K/IV)
11.5 (28) Task function for real-time OS (RTOS)
#pragma ext_table
Specifies the first address of the flash area branch table
11.5 (34) Flash area branch table
#pragma ext_func
Calls a function to the flash area from the boot area
11.5 (35) Function call function from the boot area to the flash area.
#pragma inline
Expands the standard library functions memcpy and memset inline
11.5 (38) Memory manipulation function
#pragma addnaccess
Uses 3-byte address reference/generation function
11.5 (41) Three-byte address reference/generation function
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11.5 How to Use Extended Functions
This section describes the extended functions in the following format.
FUNCTION:
Outlines the function that can be implemented with the extended function.
EFFECT:
Explains the effect brought about by the extended function.
USAGE:
Explains how to use the extended function.
EXAMPLE:
Gives an application example of the extended function.
RESTRICTIONS:
Explains restrictions if any on the use of the extended function.
EXPLANATION:
Explains the above application example.
COMPATIBILITY:
Explains the compatibility of a C source program developed by another C compiler when it is to be compiled with this
C compiler.
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(1) callt functions
callt Functions
callt/
_
_
_
_ ____callt
FUNCTION
The callt instruction stores the address of a function to be called in an area [40H to 7FH] called the callt table,
so that the function can be called with a shorter code than the one used to call the function directly.
To call a function declared by the callt (or _ _ callt) (called the callt function), a name with ? prefixed to the
function name is used. To call the function, the callt instruction is used.
The function to be called is not different from the ordinary function.
EFFECT
The object code can be shortened.
USAGE
Add the callt/_ _ callt attribute to the function to be called as follows (described at the beginning).
callt extern
type-name function-name
_ _callt extern
type-name function-name
EXAMPLE
_ _callt void func1 (void) ;
_ _callt void func1 (void) {
:
/* function body */
:
}
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callt Functions
callt/
_
_
_
_ ____callt
RESTRICTIONS
The address of each function declared with callt/_ _ callt will be allocated to the callt table at the time of
linking object modules. For this reason, when using the callt table in an assembler source module, the
routine to be created must be made "relocatable" using symbols.
A check on the number of callt functions is made at linking time.
When the -ZA option is specified, _ _callt is enabled and callt is disabled.
When the -ZF option is specified, callt functions cannot be defined. If a callt function is defined, an error will
occur.
The area of the callt table is 40F to 70F.
When the callt table is used exceeding the number of callt attribute functions permitted, a compilation error
will occur.
The callt table is used by specifying the -QL option. For that reason, the number of callt attributes permitted
per load module and the total in the linking modules is as shown in Table 11-5.
Table 11-5. Number of callt Attribute Functions That Can Be Used When
-
-
-
-QL Option Is Specified
Number of Functions That Can Be Used
Memory Model
-QL1
-QL2
-QL3
-QL4
Small model
32
32
15
10
Medium model
32
25
8
3
Large model
32
23
6
1
Cases in which the -QL option is not used and the defaults are as shown below.
Table 11-6. Restriction on callt Function Usage
callt Function
Restriction Value
Number per load module
32 Max.
Total number in linked module
32 Max.
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EXAMPLE
(C source)
============ ca1.c ============ ============ ca2.c ============
_ _callt extern int tsub ();
void main () _ _callt int tsub ()
{
{
int ret_val; int val;
ret_val = tsub(); return val;
}
}
(Output object of assembler)
ca1
module
EXTRN
?tsub
;
Declaration
callt
[?tsub]
;
Call
ca2
module
PUBLIC _tsub
;
Declaration
PUBLIC ?tsub
;
@@CALT CSEG CALLT0
;
Allocation to segment
?tsub: DW
_tsub
@@CODE CSEG
_tsub:
;
Function definition
:
Function body
:
EXPLANATION
The callt attribute is given to the function tsub() so that it can be stored in the callt table.
COMPATIBILITY
From another C compiler to this C compiler
Modification is not required if the keyword callt/_ _ callt is not used.
When changing functions to callt functions, use the method above.
From this C compiler to another C compiler
#define must be used. For details, see 11.6 Modifications of C Source.
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(2) Register variables
Register Variables
register
FUNCTION
Allocates the declared variables (including arguments of function) to the register (RP3, VP) and saddr2 area
(_@KREG00 to _@KREG15). Saves and restores registers or saddr2 area during the preprocessing/
postprocessing of the module that declared a register.
When the -ZO option is specified, register variables are allocated in the order of declaration. When the -ZO
option is not specified (default), on the other hand, the allocation is performed based on the number of
references. Therefore, it is undefined to which register or saddr2 area the register variable is allocated. For
details of the allocation of register variables, refer to 11.7 Function Call Interface.
Register variables are allocated to different areas depending on the compilation condition as shown below (for
each option, refer to the CC78K4 C Compiler Operation User's Manual (U15557E)).
1.
Register variables are allocated to saddr2 area only when the -QR option is specified.
2
When the -QF option is specified and the -ZO option is not specified, register variables are also allocated
also to register UP.
3.
When neither the -ZO option nor the -QF option is specified, all the register arguments and register
variables are allocated to registers and saddr2 area. When there is no argument or automatic variable
allocated to the stack area (that is, a stack frame is not generated), register variables are also allocated to
register UP (when the -ML option is specified and the -QR option is not specified, however, register
variables are allocated only if the total size allocated to the register is 6 bytes or less assuming the pointer
is 3 bytes).
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Register Variables
register
These are summarized in Table 11-7.
Table 11-7. Registers to Allocate Register Variables
Without ZO
Option Specification
Registers to Allocate
Without -QR
RP3, VP
With QR
RP3, VP, saddr2 area (_@KREG00 to _@KREG15)
With -QF *1
RP3, VP, UP
Without -QF
and a stack frame not generated *2
RP3, VP, UP
Above *1 or *2 and with -QR
RP3, VP, UP, saddr2 area (_@KREG00 to _@KREG15)
With ZO
Option Specification
Registers to Allocate
Without -QR
RP3, VP
With -QR
RP3, VP, saddr2 area (_@KREG00 to _@KREG15)
With -QF *1
RP3, VP
Without -QF
and a stack frame not generated *2
RP3, VP
Above *1 or *2 and with -QR
RP3, VP, saddr2 area (_@KREG00 to _@KREG15)
EFFECT
Instructions to the variables allocated to the register or saddr2 area are generally shorter in code length than
those to memory. This helps shorten object code and also improves program execution speed.
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Register Variables
register
USAGE
Declare a variable with the register storage class specifier as follows.
Register
type-name variable-name
EXAMPLE
void main (void) {
register unsigned char c;
:
}
RESTRICTIONS
If register variables are not used so frequently, object code may increase (depending on the size and contents
of the source).
Register variable declarations may be used for char/int/short/long/float/double/long double and pointer
data types.
With the medium model, function pointers are allocated to saddr2 area for register variables. Function
pointers cannot be allocated to registers.
A char type register variable uses only half the space required for the register variable of any other type. A
long/float/double/long double type variable uses twice the space.
The function pointer type of the medium model and the pointer of the large model use one and a half the
amount of space.
All the types have byte boundaries.
If the register variables exceed the `usable number' shown in Table 11-8, they are handled the same as
automatic variables without a register storage class specifier and allocated to ordinary memory space.
Up to 20 bytes or 22 bytes can be allocated as register variables (6 bytes when 16 bytes of saddr2 area and
4 bytes of registers or UP are used).
Table 11-8. Restrictions on Register Variables Usage
Data Type
Usable Number (Per Function)
int/short
10 variables max.
Function pointer of medium model
5 variables max.
Pointer of large model
6 variables max.
long/float/double/long double
5 variables max.
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Register Variables
register
EXAMPLE 1
1. Example of register variable allocation to register
(With the large model, and when the optimization option is the default)
(C source 1)
void main () {
register int i, j;
j = 0;
j = 1;
I + = j;
}
(Output object of compiler)
@@CODE CSEG
_main:
push
uup
;
Saves register contents at the beginning of the function.
Push
rp3
;
subw
rp3, rp3
;
Assigns 0 to i
movw
up, #01H
;
Assigns 1 to j
addw
rp3, up
;
Assigns i to the result of i + j
pop rp3
;
Restores register contents at the end of the function.
Pop uup
;
ret
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Register Variables
register
EXAMPLE 2
2. Example of register variable allocation to register and saddr2 area
(With the large model, and when the optimization option -QR is specified)
(C source 2)
void main () {
register unsigned int a, b, c, d;
d = a - b;
d = b - c;
}
(Output object of compiler)
EXTRN
SADDR2(_@KREG00)
;
Performs reference declaration of saddr2 area to be used.
PUBLIC
_main
@@CODE
CSEG
_main;
push
uup
;
Saves register contents at the beginning of the function.
push
rp3
;
push
vvp
;
movw
ax, _@KREG00
;
Saves contents of saddr2 are at the beginning of the function.
push
ax
movw
ax, rp3
;
subw
ax, up
;
a
- b
movw
vp, ax
;
Assigns the result of a
- b to d
movw
ax, up
subw
ax, _@KREG00
;
b
- c
movw
vp, ax
;
Assigns the result of b
- c to d
pop
ax
movw
_@KREG00, ax
;
Restores contents of saddr2 area at the end of the function.
pop
vvp
pop
rp3
pop
uup
;
Restores register contents at the end of the function.
ret
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5HJLVWHU 9DULDEOHV
UHJLVWHU
EXPLANATION
To use register variables, you only need to declare them with the register storage class specifier.
Label _@KREG00, etc. includes the modules declared with PUBLIC in the library attached to this C compiler.
COMPATIBILITY
From another C compiler to this C compiler
Modification is not required if the other C compiler supports register declarations.
When changing to register variables, add the register declarations for the variables to the program.
From this C compiler to another C compiler
Modification is not required if the other compiler supports register declarations.
How many variable registers can be used and to which area they will be allocated depends on the
implementation of the other C compiler.
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(3) How to use the saddr area
Usage of saddr Area
sreg/_ _sreg
(1) Usage with sreg declaration
FUNCTION
The external variables and in-function static variables (sreg variables) declared with the keyword sreg or
_ _sreg are automatically allocated to saddr2 [XFD20H to XFDFFH] area with relocatability (X: 0 or F by
specifying location). When those variables exceed the area shown above, a compilation error occurs.
The sreg variables are treated in the same manner as the ordinary variables in the C source.
Each bit of sreg variables of char, short, int, and long type becomes a boolean type variable automatically.
sreg variables declared without an initial value take 0 as the initial value.
The area of sreg variables declared in the assembler source that can be referenced is the saddr2 area
[XFD20H to XFDFFH]. When the -QR option is specified, however, the compiler may use up to 32 MB of
saddr2 area, so care must be taken (refer to Table 11-3 Utilization of Memory Space).
EFFECT
Instructions to the saddr2 area are generally shorter in code length than those to memory. This helps shorten
object code and also improves program execution speed.
USAGE
Declare variables with the keywords sreg and
_
_
_
_ ____sreg inside a module and a function that defines the
variables. Only a variable with a static storage class specifier can become a sreg variable inside a function.
sreg
type-name variable-name / sreg static type-name
variable-name
_ _sreg
type-name variable-name / _ _sreg static
type-name
variable-name
Declare the following variables inside a module that refers to sreg external variables. They can be described
inside a function as well.
extern sreg
type-name variable-name / extern _ _sreg type-name variable-name
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Usage of saddr Area
sreg/_ _sreg
RESTRICTIONS
If const type is specified, or if sreg/_ _sreg is specified for a function, a warning message is output, and the
sreg declaration is ignored.
Arguments of functions and automatic variables cannot be specified to this area.
char type uses half the space of other types and long/float/double/long double types use twice the space.
Function pointers of the medium model and the large model use one and a half the amount of space as other
types.
All the types have byte boundaries.
When -ZA is specified, only _ _sreg is enabled and sreg is disabled.
The following shows the maximum number of sreg variables that can be used per load module.
Table 11-9. Restrictions on sreg Variable Usage
Data Type
Usable Number of sreg Variables (Per Load Module)
int/short
Max. 112 (96 when -QR is specified)
Note
Function pointer of medium model
Max. 74 (64 when -QR is specified)
Note
Pointer of large model
Max. 74 (64 when -QR is specified)
Note
Note When the -QR option is not specified, the reserved area for the argument of the norec function/automatic
variables and register variables (32 bytes of saddr2 area) can be used as sreg variable area. When bit and
boolean type variables are used, the usable number is decreased.
EXAMPLE
The following shows an example when the large model is used.
(C source)
extern sreg int hsmm0;
extern sreg int hsmm1;
extern sreg int *hsptr;
void main ( ) {
hsmm0 -= hsmm1;
}
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Usage of saddr Area
sreg/_ _sreg
(Assembler source)
The following example shows a definition code for an sreg variable that the user creates. If an extern declaration is
not made in the C source, the C compiler outputs the following codes. In this case, the ORG quasi directive will not
be output.
PUBLIC _hsmm0
;
Declaration
PUBLIC _hsmm1
;
PUBLIC _hsptr
;
@@DATS
DSEG
SADDR2
;
Allocation to segment
ORG
0FFD20H
;
_hsmm0:
DS (2)
;
_hsmm1:
DS (2)
;
_hsptr:
DS (3)
;
(Output object of compiler)
EXTRN SADDR2(_hsmm1)
EXTRN SADDR2(_hsmm0)
PUBLIC _main
@@CODE CSEG
_main:
subw _hsmm0, _hsmm1
ret
COMPATIBILITY
From another C compiler to this C compiler
Modification is not required if the other compiler does not use the keyword sreg/_ _sreg.
When changing to sreg variable, use the method above.
From this C compiler to another C compiler
Modifications are made by #define. For details, refer to 11.6 Modifications of C Source. By this
modification, sreg variables are handled as ordinary variables.
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Usage of saddr Area
-RD
(2) Usage with saddr automatic allocation option of external variables/external static variables
FUNCTION
External variables/external static variables (except const type) are automatically allocated to the saddr2 area
regardless of whether an sreg declaration is made or not.
Depending on the value of n, the external variables and external static variables to allocate can be specified
as follows.
Table 11-10. Variables Allocated to saddr2 Area by -RD Option
Value of n
Variables Allocated to saddr2 Area
If 1
Variables of char and unsigned char types
If 2
Variables if n is 1 and variables of short, unsigned short, int, unsigned int, enum,
small model pointer, and medium model data pointer type
If 4
Variables if n is 2 and variables of long, unsigned long, float, double, long double,
medium model pointer, and large model pointer type
If omitted
All variables (including structures, unions, and arrays in this case only)
Variables declared with the keyword sreg are allocated to the saddr2 area, regardless of the above
specification.
The above rule also applies to variables referenced by an extern declaration, and processing is performed as
if these variables were allocated to the saddr2 area.
The variables allocated to the saddr2 area by this option are treated in the same manner as the sreg
variable. The functions and restrictions of these variables are as described in (1).
METHOD OF SPECIFICATION
Specify the -RD [n] (n: 1, 2, or 4) option.
RESTRICTIONS
With the -RD [n] option, modules specifying different n values cannot be linked to each other.
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Usage of saddr Area
-RS
(3) Usage with saddr automatic allocation option of internal static variables
FUNCTION
Automatically allocates internal static variables (except const type) to saddr2 area regardless of an sreg
declaration.
Depending on the value of n, the internal static variables to allocate can be specified as follows.
Table 11-11. Variables Allocated to saddr2 Area by -RS Option
Value of n
Variables Allocated to saddr2 Area
If 1
Variables of char and unsigned char types
If 2
Variables if n is 1 and variables of short, unsigned short, int, unsigned it, enum,
small model pointer, and medium model data pointer type
If 4
Variables if n is 2 and variables of long, unsigned long, float, double, long double,
medium model function pointer, and large model pointer type
If omitted
All variables (including structures, unions, and arrays in this case only)
Variables declared with the keyword sreg are allocated to the saddr2 area regardless of the above
specification.
The variables allocated to the saddr2 area by this option are handled in the same manner as the sreg
variable. The functions and restrictions for these variables are as described in (1).
METHOD OF SPECIFICATION
Specify the -RS [n] (n: 1, 2, or 4) option.
Remark
With the -RS [n] option, modules specifying different n values can also be linked to each other.
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Usage of saddr Area
_ _sreg1
(4) Usage with _ _sreg1 declaration
FUNCTION
Variables declared with the keyword _ _sreg1 (called sreg1 variables) are automatically allocated to saddr1
[XFE00H to XFE7FH] area (x: 0 or F by specifying location) with relocatability. When the sreg1 variable
exceeds the area shown above, a compilation error occurs.
saddr1 area [XFE00H to XFEFFH] can be used as sreg1 variables by changing the location of segments in
the assembler source or at the time of linking. However, care must be taken because the compiler uses the
area [XFE80H to XFEFFH] as a general-purpose register area.
The sreg1 variables are handled in the same manner as ordinary variables in the C source.
Each bit of sreg1 variables of char/short/int/long type automatically becomes a _ _boolean1 type variable.
sreg1 variables declared without an initial value take 0 as the initial value.
EFFECT
Instructions to the saddr1 area are generally shorter in code length than those to memory. This helps shorten
object code and also improves program execution speed.
USAGE
Declare a variable with the keyword _ _sreg1 inside the module in which the variable is to be defined.
_ _sreg1
type-name variable-name
Declare the following variables inside the module in which the sreg1 variable is referenced.
extern _ _sreg1
type-name variable-name
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Usage of saddr Area
_ _sreg1
RESTRICTIONS
When _ _sreg1 type is specified for a const type or function, a warning message is output and the _ _sreg1
declaration is ignored.
Arguments of functions and automatic variables cannot be specified to this area.
char type uses half the space of other types, and long/float/double/long double types use twice the space.
All the types have byte boundaries.
Medium model function pointers and large model pointers use one and a half the space of other types.
The following shows the maximum number of sreg variables that can be used per load module.
Table 11-12. Restrictions on sreg1 Variable Usage
Data Type
Usable Number of sreg Variables (Per Load Module)
int/short
Max. 64
Note
Medium model function pointer
Max. 42
Note
Large model pointer
Max. 42
Note
Note
saddr1 area [XFE00H to XFE7FH] is used. When _ _boolean1 type variables are used, the usable
number is decreased.
EXAMPLE
The following shows an example when the large model is used.
(C source)
extern _ _sreg1 int s1;
extern _ _sreg1 int s2;
extern _ _sreg1 int *spr;
void main( ) {
s1 -= s2;
}
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Usage of saddr Area
_ _sreg1
(Assembler source)
The following example shows a definition code for a sreg1 variable that the user creates. If an extern declaration is
not made in the C source, the C compiler outputs the codes in the same way as those of assembler source. In this
case, the ORG quasi directive will not be output.
PUBLIC _s1
;
Declaration
PUBLIC _s2
;
PUBLIC _sptr
;
@@DATS1 DSEG SADDR
;
Allocation to segment
ORG
0FFE00H
;
_s1:
DS
(2)
;
_s2:
DS
(2)
;
_sptr:
DS
(3)
;
(Output object of compiler)
EXTRN
_s2
EXTRN
_s1
PUBLIC
_main
@@CODE
CSEG
_main:
subw
_s1,_s2
ret
COMPATIBILITY
From another C compiler to this C compiler
Modification is not required if the keyword _ _sreg1 is not used in the program.
When changing to sreg1 variables, use the method above.
From this C compiler to another C compiler
#define must be used. For details, see 11.6 Modifications of C Source. By this modification, sreg1
variables will be handled as ordinary variables.
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(4) How to use the sfr area
Usage of sfr Area
sfr
FUNCTION
The sfr area refers to a group of special function registers such as mode registers and control registers for the
various peripherals of the 78K/IV Series microcontrollers.
By declaring use of sfr names, manipulations on the sfr area can be described at the C source level.
sfr variables are external variables without initial values (undefined).
A write check will be performed on read-only sfr variables.
A read check will be performed on write-only sfr variables.
Assignment of illegal data to an sfr variable will result in a compilation error.
The sfr names that can be used are those allocated to an area consisting of addresses FF00H to FFFFH with
the small model, or XFF00H to XFFFFH with the medium large model. (x: 0 or F by specifying location)
EFFECT
Manipulations on the sfr area can be described at the C source level.
Instructions to the sfr area are shorter in code length than those to memory. This helps shorten object code
and also improves program execution speed.
USAGE
Declare the use of an sfr name in the C source with the #pragma preprocessing directive, as follows. (The
keyword sfr can be described in uppercase or lowercase letters.).
#pragma sfr
The #pragma sfr directive must be described at the beginning of the C source line. If #pragma PC
(processor type) is specified, however, describe #pragma sfr after that.
The following statement and directives may precede the #pragma sfr directive.
.
Comment statement
.
Preprocessing directives that do not define or refer to a variable or function
In the C source program, describe an sfr name that the device has as is (without change). In this case, the
sfr need not be declared.
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Usage of sfr Area
sfr
RESTRICTIONS
All sfr names must be described in uppercase letters. Lowercase letters are treated as ordinary variables.
EXAMPLE
(C source)
#ifdef _ _K4_ _
#pragma sfr
#endif
void main ()
{
CMK00 = 1;
PM0 = 0x11;
P0 = 10;
:
}
(Output object of compiler)
The C compiler outputs no declaration-related code but outputs the following code inside the function.
@@CODE CSEG
_main:
set1
CIC00.6
mov
PM0, #011H ;17
sub
P0, #0AH ;10
ret
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Usage of sfr Area
sfr
EXPLANATION
In the above example, use of sfr variables is declared with the #pragma sfr directive. By this declaration,
special function registers such as P0 (port 0) and CIC00 (one of the interrupt control registers
490
) can be used.
Note Bit 6 of the CIC00 register has the SFR bit name CMK00. For sfr, refer to the user's manual of the
target device used.
COMPATIBILITY
From another C compiler to this C compiler
Modification is not required if those portions of the C source program do not depend on the device or
compiler.
From this C compiler to another C compiler
Delete the #pragma sfr statement or sort by #ifdef and add the declaration of the variable that was formerly
an sfr variable. The following shows an example.
#ifdef _ _K4_ _
#pragma sfr
#else
/*
declaration of variables */
unsigned char P0;
#endif
void main(void) {
P0 = 0;
}
In the case of a device that has the sfr or its alternative functions, a dedicated library must be created to
access that area.
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(5) noauto function
noauto Function
noauto
FUNCTION
The noauto function sets restrictions for automatic variables not to output the codes of preprocessing/
postprocessing (generation of stack frame).
All the arguments are allocated to registers. If there is an argument that cannot be allocated to registers, a
compilation error occurs.
(a) When -ZO option is specified
Arguments are passed via registers.
The locations where arguments are passed to the function call side and the function definition side become
the locations where arguments are allocated.
The save and restore of the register to which arguments are allocated are performed before/after the
function call.
Automatic variables cannot be used.
Arguments are allocated in the same order as ordinary functions.
Table 11-13 shows the registers to which the arguments of the noauto function are passed/allocated.
Table 11-13. Registers Used for noauto Function Arguments (With -ZO)
Data Type
First Argument
Second Argument
Third Argument or Later
char
R6
R7
R8, R9, R10, R11
int, short
RP3
VP
UP
(only when
-
-
-
-MS ----QF is
specified)
long/float/double/
long double
VP (higher 16 bits)
RP3 (lower 16 bits)
Small model pointer
VP
UP (only when
-
-
-
-QF is specified)
RP3
Large model pointer
VVP
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noauto Function
noauto
(b) When -ZO option is not specified
Arguments are passed on the function call side in the same manner as ordinary functions (refer to 11.7.2
Ordinary function call interface).
The arguments passed via a register or stack are copied to the register shown in Table 11-14 on the
function definition side (copying register is necessary even when an argument is passed via a register
because the registers of the function call side and the function definition side are different).
The save and restore of registers to which arguments are allocated are performed on the function definition
side.
Table 11-14. Registers Used for noauto Function Arguments (Without -ZO)
Data Type
First Argument
Second Argument
Third Argument or Later
char (with 4-byte argument)
Note
char (without 4-byte argument)
Note
R10
R6
R11
R7
R6, R7, R8, R9, R10,
R11, R8, R9
int, short, enum
(with 4-byte argument)
Note
(without 4-byte argument)
Note
UP
RP3
RP3
UP
VP
VP
long/float/double/long double
VP (higher 16 bits)
RP3 (lower 16 bits)
Small model pointer
Medium model data pointer
UP
VP
RP3
Large model pointer
UUP
VVP
Note 4-byte arguments are arguments of long, float, double, long double type
Remarks 1.
The medium model function pointer cannot be used as an argument to be allocated to a register.
2.
The order of the register allocation in this function is the same as the order when the -QF option is
specified in ordinary functions.
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noauto Function
noauto
Automatic variables can be used only when all the automatic variables can be allocated to the registers
remaining after the argument allocation and to the saddr2 area (_@KREGXX) for register variables.
However, automatic variables are allocated to the saddr2 area for register variables only when the -QR option
is specified during compilation. If the -QRO option is specified during compilation, a warning message is
output and automatic variables are not allocated to saddr2 area.
Automatic variables are allocated in the same order as arguments are allocated. The automatic variables
allocated to saddr2 area (_@KREGXX) are allocated in the order of declaration (if they are not allocated, a
compilation error occurs).
The save and restore of _@KREGXX, the register to which automatic variables are allocated, are performed
on the function definition side.
EFFECT
The object code can be shortened and execution speed can be improved.
USAGE
Declare a function with the noauto attribute in the function declaration, as follows.
noauto
type-name function-name
RESTRICTIONS
When the -ZO option is specified, automatic variables cannot be used inside the noauto function, and neither
can the register variables.
When the -ZA option is specified, the noauto function is disabled.
The arguments and automatic variables of the noauto function (only when the -ZO option is specified) have
restrictions on their types and numbers. The following shows the types of arguments that can be used inside
a noauto function.
Pointer
char / signed char/ unsigned char
int / signed int / unsigned int
short / signed short / unsigned short
enum
long / signed long / unsigned long
float / double / long double
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noauto Function
noauto
Table 11-15. Restrictions on noauto Function Arguments (With -ZO)
Data Type
Restriction
Type other than pointer
Max. 4 bytes (Max. 6 bytes)
Note
Small model pointer
Max. 4 bytes (Max. 6 bytes)
Note
Medium model data pointer
Max. 4 bytes
Large model pointer
Max. 1 variable
Note Up to 6 bytes can be used only when the -MS and -QF options are specified.
Table 11-16. Restrictions on noauto Function Arguments and Automatic Variables (Without -ZO)
Data Type
Restriction
Type other than pointer
Max. 6 bytes (Max. 22 bytes)
Note 1
Small model pointer
Medium model data pointer
Max. 6 bytes (Max. 22 bytes)
Note 1
Medium model function pointer
(Max. 5 variables)
Note 2
Large model pointer
Max. 2 variables (Max. 7 variables)
Note 3
Notes 1.
When the -QR option is specified, only automatic variables can be used up to 22 bytes.
2.
When the -QR option is specified, only automatic variables can be used up to 5 variables. The
medium model function pointer cannot be used as a register argument (not allocated to registers).
3.
When the -QR option is specified, only automatic variables can be used up to 7 variables.
These restrictions are checked during compilation.
If arguments and automatic variables are declared with a register (only when the -ZO is not specified), the
register declaration is ignored.
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noauto Function
noauto
EXAMPLE
(C source)
noauto short nfunc (short, short, short);
short l, m;
void main (void)
{
static short s1, s2, s3;
l = nfunc (s1, s2, s3);
}
noauto short nfunc(short a, short b, short c)
{
m = a + b + c;
rturn(m);
}
(Output object of compiler) With small model, when -ZO option is not specified
@@DATA
DSEG
_l :
DS
(2)
_m :
DS
(2)
?L0003: DS
(2)
?L0004: DS
(2)
?L0005: DS
(2)
@@CODES CSEG
BASE
_main: s3
push
ax
movw
ax,!?L0004
;
s2
push
ax
movw
ax,!?L0003
;
s1
call
!_nfunc
;
Calls nfunc (a, b, c)
pop
ax,de
movw
!_l,bc
;
Assigns return value to external variable l
ret
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noauto Function
noauto
(Output object of compiler ... continued)
_nfunc:
push
rp3,vp,up
;
Saves register for arguments
movw
rp3,ax
;
Assigns first argument a to RP3
movw
ax,[sp+9]
;
Assigns second argument b to UP
movw
up,ax
;
movw
ax,[sp+11]
;
Assigns third argument c to VP
movw
vp,ax
;
movw
ax,rp3
;
To a (RP3)
addw
ax,up
;
Adds b (UP)
addw
ax,vp
;
Adds c (VP)
movw
!_m,ax
;
Assigns the result of operation to external variable m
movw
bc,ax
;
Returns external variable m
pop
rp3,vp,up
;
Restores register for arguments
g
EXPLANATION
In the above example, the noauto attribute is added at the header part of the C source.
noauto is declared and stack frame formation is not performed.
COMPATIBILITY
From another C compiler to this C compiler
Modification is not required if the keyword noauto is not used.
When changing variables to noauto variables, modify the program according to the method above.
From this C compiler to another C compiler
#define must be used. For details, see 11.6 Modifications of C Source.
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(6) norec function
norec Function
norec
FUNCTION
A function that does not call another function by itself can be changed to a norec function.
With the norec function, code for preprocessing and postprocessing (stack frame formation) is not output.
All the arguments of norec function are allocated to registers and saddr2 area (_@NRARGX) for arguments
of the norec function. When the -QR option is not specified during compilation (default), however, saddr2
area is not used.
If arguments cannot be allocated to registers and saddr2 area, a compilation error occurs.
(a) When -ZO option is specified
Arguments are passed via a register and saddr2 area (_@NRARGX). When a register is used, arguments
are stored in the same manner as the noauto function (refer to Table 11-13).
If arguments cannot be passed via a register, a register is not used, but arguments are passed via saddr2
area (_@NRARGX) (a register and saddr2 area are not used simultaneously).
When saddr2 area is used, arguments are sequentially stored in ascending order from _@NRARG0
starting from the first argument.
The locations where arguments are passed on the function call side and the function definition side
become the locations where arguments are allocated.
The save and restore of the register to which arguments are allocated are performed before/after the
function call.
Automatic variables are allocated to saddr2 area (_@NRATXX), and so are the register variables. They
are allocated in the sequence they have been declared in ascending order starting from _@NRAT00. If
there are excess registers for arguments, automatic variables are allocated to registers first. However,
automatic variables are allocated to saddr2 area only when the -QR option is specified. If automatic
variables cannot be allocated to registers or saddr2 area, a compilation error occurs.
The save and restore of the register to which automatic variables are allocated are performed on the
function definition side.
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norec Function
norec
(b) When -ZO option is not specified
On the function call side, arguments are passed via a register and saddr2 area (_@NRARGX) for the
arguments of norec functions. On the function definition side, the arguments passed via a register are copied
to a register (because the registers of the function call side and the function definition side are different). If
arguments are passed via saddr2 area, the location where arguments are passed becomes the location
where arguments are allocated.
Arguments are allocated to registers first, and then the arguments that cannot be allocated to registers are
allocated to saddr2 area.
The save and restore of registers to store arguments are performed on the function definition side.
Automatic variables are allocated to registers or to saddr2 area (_@NRARGX) for the arguments of the norec
function if registers can be used. If the areas above cannot be used, automatic variables are allocated to
saddr2 area (_@NRATXX) for the automatic variables of the norec function in the sequence they have been
declared and in ascending order.
The following shows the registers to be used for passing the arguments of norec functions.
Table 11-17. Registers Used for norec Function Arguments: Passing Side (Without -ZO)
Data Type
First Argument
Second Argument
Third Argument or Later
char
A
C
DE, RP2, saddr2
Note
int, short, enum
AX
DE
RP2, saddr2
Note
long/float/double/
long double
DE (higher 16 bits)
AX (lower 16 bits)
saddr
Note
saddr2
Small model pointer
Medium model data pointer
AX
DE
RP2, saddr2
Note
Large model pointer
TDE
saddr2
Note
saddr2
Note
Note
When the -QR option is specified, there arguments can be passed via _@NRARGX (saddr2). Medium
model function pointers (3 bytes) cannot be used as the arguments to be allocated to registers.
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norec Function
norec
Table 11-18. Registers Used for norec Function Arguments: Receiving Side (Without -ZO)
Data Type
First Argument
Second Argument
Third Argument or Later
char (with 4-byte arguments)
Note 1
char (without 4-byte arguments)
Note 1
R10
R6
R11
R7
R6, R7, R8, R9, saddr2
Note 2
R10, R11, R8, R9, saddr2
Note 2
int, short, enum
(without 4-byte arguments)
Note 1
(with 4-byte arguments)
Note 1
UP
RP3
RP3
UP
VP, saddr2
Note 2
VP, saddr2
Note 2
long/float/double/long double
VP (higher16 bits)
RP3 (lower 16 bits)
saddr2
Note 2
saddr2
Note 2
Small model pointer
Medium model data pointer
UP
VP
RP3, saddr2
Note 2
Large model pointer
VVP
saddr2
Note 2
saddr2
Note 2
Notes 1
4-byte arguments are arguments of long, float, double and long double type
2
When the -QR option is specified, these arguments can be passed via _@NRARGX (saddr2). The
medium model's function pointer (3 bytes) cannot be used as an argument assigned to the register.
Cautions 1.
The medium model function pointers cannot be used as arguments to be allocated to
registers.
2.
The order of allocating registers of this function is the same as that of an ordinary function
with the -QF option specified.
EFFECT
The object code can be shortened and program execution speed can be improved.
USAGE
Declare a function with the norec attribute in the function declaration as follows.
norec
type-name function-name
_ _ leaf can also be described instead of norec.
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norec Function
norec
RESTRICTIONS
No other function can be called from a norec function.
There are restrictions on the type and number of arguments and automatic variables that can be used in a
norec function.
When -ZA is specified, norec is disabled and only _ _leaf is enabled.
The restrictions for arguments and automatic variables are checked during compilation, and an error occurs.
If arguments and automatic variables are declared with a register, the register declaration is ignored.
The following shows the types of arguments and automatic variables that can be used in norec functions.
Pointer
char/signed char/unsigned char
int/signed int/unsigned int
short/signed short/unsigned short
long/signed long/unsigned long
float/double/long double
(a) Restrictions for arguments of function when -ZO option is specified
The char type arguments do not perform int extension.
Table 11-19. Restrictions on norec Function Arguments (When -ZO Is Specified)
Data Type
Restriction
char type
Max. 8 variables
int, short, small model pointer type
Max. 4 variables
Large model pointer, long, float, double, long double type
Max. 2 variables
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norec Function
norec
(b) Restrictions for arguments of function when -ZO option is not specified
Table 11-20. Restrictions on norec Function Arguments (When -ZO Is Not Specified)
Data Type
Restriction
Other than pointer
Max. 14 bytes (Max. 6 bytes)
Note
Small model pointer, medium model data pointer
Max. 14 bytes (Max. 6 bytes)
Note
Medium model function pointer
Max. 2 variables (cannot be used)
Note
Large model pointer
Max. 3 variables (Max. 1 variable)
Note
Note The figures enclosed in parentheses indicate values when -QR is not specified.
(c) Restrictions for automatic variables when -ZO option is specified
Up to 8 bytes of the automatic variables can be used in the norec function.
If there are excess registers used for arguments, they are added to the 8 bytes. Automatic variables are
allocated to saddr2 area in 1-byte alignment.
In the case that the -QR option is not specified during compilation, if the total size of the arguments and
automatic variables exceeds 4 bytes (6 bytes when -MS -QF is specified), an error occurs.
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norec Function
norec
(d) Restrictions for automatic variables when -ZO option is not specified
The automatic variables that can be used are allocated to the registers remaining after allocation of
arguments, saddr2 area (_@NRARGX) for the arguments of norec functions, and saddr2 area (_@NRATXX)
for automatic variables of norec functions.
Table 11-21. Restrictions on norec Function Automatic Variables (When -ZO Is Not Specified)
Data Type
Restriction
Other than pointer
Max. 22 bytes (Max. 6 bytes)
Note
Small model pointer, medium model data pointer
Max. 22 bytes (Max. 6 bytes)
Note
Medium model function pointer
Max. 4 variables (cannot be used)
Note
Large model pointer
Max. 6 variables (Max. 2 variable)
Note
Note The figures enclosed in parentheses indicate values when -QR is not specified.
EXAMPLE
(C source)
norec int rout (int a, int b, int c);
int i, j;
void main ( ) {
int k, l, m;
i = l + rout (k, l, m) + ++k ;
}
norec int rout (int a, int b, int c)
{
int x, y;
return (x + (a<<2));
}
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norec Function
norec
(Output object of compiler) (With large model, when QR option is specified, and -ZO option is not specified)
EXTRN SADDR2 (_@NRARG0)
;
Refers to saddr2 area to be used.
PUBLIC
_rout
PUBLIC
_I
PUBLIC
_j
PUBLIC
_main
@@DATA DSEG
_i:
DS
(2)
_j:
DS
(2)
@@CODE CSEG
_main:
push
uup
subwg
sp, #06H
movg
whl, sp
movg
uup, whl
movw
ax, [up+2]
;
Stores argument l to register RP2.
movw
rp2, ax
movw
ax, [up]
;
Stores argument m to register DE.
movw
de, ax
movw
ax, [up+4]
;
Stores argument k to register AX.
call
$!_rout
;
Calls norec function
movw
ax, [up+2]
;
Adds return value of norec function to l.
addw
bc, ax
;
movw
ax, [up+4]
;
Increments k
incw
ax
;
movw
[up+4], ax
;
addw
bc, ax
;
Assigns the result of addition to i.
movw
!!_i, bc
addwg
sp, #06H
pop
uup
ret
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norec Function
norec
(Output object of compiler...continued)
_rout:
push
uup
Saves register for arguments.
push
rp3
;
push
vvp
;
movw
rp3, ax
;
Assigns the first argument a to RP3.
movw
vp, de
;
Assigns the third argument c to VP.
movw
up, rp2
;
Assigns the second argument b to UP.
movw
ax, rp3
;
Receives the first argument a from register RP3.
shlw
ax, 2
;
addw
ax, _@NRARG0
;
Automatic variable x assigned to saddr2
movw
bc, ax
;
Assigns return value to BC register
L0004:
pop
vvp
;
Restores registers for arguments.
pop
rp3
pop
uup
ret
END
EXPLANATION
In the above example, the norec attribute is added in the definition of the rout function as well to indicate that the
function is norec.
COMPATIBILITY
From another C compiler to this C compiler
Modification is not required if the keyword norec is not used.
When changing variables to norec variables, modify the program according to the method above.
From this C compiler to another C compiler
#define must be used. For details, see 11.6 Modifications of C Source.
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(7) bit type variables
bit Type Variables
bit
boolean Type Variables
boolean
_ _boolean
FUNCTION
A bit or boolean type variable is handled as 1-bit data and allocated to saddr2 area.
These variables can be handled the same as an external variable that has no initial value (or has an unknown
value).
The C compiler outputs the following bit manipulation instructions for these variables.
MOV1, AND1, OR1, XOR1, SET1, CLR1, NOT1, BT, BF
instructions
EFFECT
Programming at the assembler source level can be performed in C, and the saddr and sfr areas can be
accessed in bit units.
USAGE
Declare a bit or boolean type inside the module in which the bit or boolean type variable is to be used, as
follows.
_ _boolean can also be described instead of bit.
Bit
variable-name
Boolean
variable-name
_ _boolean
variable-name
Declare a bit or boolean type inside the module in which the bit or boolean type variable is to be used, as
follows.
extern bit
variable-name
extern boolean
variable-name
extern _ _boolean
variable-name
char, int, short, and long type sreg variables (except the elements of arrays and members of structures) and
8-bit sfr variables can be automatically used as bit type variables.
variable-name.n (where n = 0 to 31)
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bit Type Variables
bit
boolean Type Variables
boolean
_ _boolean
RESTRICTIONS
An operation on two bit or boolean type variables is performed by using the carry flag.
For this reason, the contents of the carry flag between statements are not guaranteed.
Arrays cannot be defined or referenced.
A bit or boolean type variable cannot be used as a member of a structure or union.
This type of variable cannot be used as the argument type of a function.
The variable cannot be declared with an initial value.
If the variable is described along with a const declaration, the const declaration is ignored.
Only operations using 0 and 1 can be performed by the operators and constants shown in the following table.
*, & (pointer reference, address reference), and sizeof operations cannot be performed.
When the -ZA option is specified, only _ _boolean is enabled.
Table 11-22. Operators That Use Only Constants 0 or 1 (When Using bit Type Variable)
Classification
Operator
Classification
Operator
Assignment
=
Bitwise AND
&, &=
Bitwise OR
|, |=
Bitwise XOR
^, ^=
Logical AND
&&
Logical OR
||
Equal
==
Not Equal
!=
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bit Type Variables
bit
boolean Type Variables
boolean
_ _boolean
Table 11-23. Number of Usable bit Type Variables
Condition
Restrictions (Per Load Module)
When -QR option is specified
(saddr2 area [XFD20H to XFDDFH])
Max. 1536 variables can be used.
When -QR option is not specified
(saddr2 area [XFD20H to XFDFFH])
Max. 1792 variables can be used.
The number of usable bit type variables is decreased if sreg variables are used or the -RD and -RS (automatic
saddr allocation option) options are specified.
EXAMPLE
(C source)
#define ON
1
#define OFF
0
extern void testb (void);
extern void chgb (void);
extern bit data1;
extern _ _boolean data2;
void main () {
data1 = ON;
data2 = OFF;
while (data1) {
data1 = data2;
testb();
}
if (data1 && data2) {
chgb();
}
}
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bit Type Variables
bit
boolean Type Variables
boolean
_ _boolean
(Assembler source)
Indicates the case where the user creates a definition code of a bit type variable. The following example shows
the case of the large model (-ML) and the location 0FH (-CS15). In this example, if the compiler output section
name @@ BITS is used, a link error occurs since the bit segment is changed to the AT attribute. Therefore,
other segment names should be used (if the attribute is saddr2, the @@BITS segment name can be used).
PUBLIC _data1
;
Declaration
PUBLIC _data2
BIT_SEG BSEG
AT 0FFD20H
;
Allocation to segment
_data1 DBIT
_data2 DBIT
(Output object of compiler)
If an extern declaration is not added, the compiler outputs the codes shown below. The following shows the
case of the large model.
EXTRN _testb
EXTRN _chgb
PUBLIC _data1
PUBLIC _data2
PUBLIC _main
@@BITS BSEG SADDR2
_data1 DBIT
_data2 DBIT
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bit Type Variables
bit
boolean Type Variables
boolean
_ _boolean
(Output object of compiler...continued)
@@CODE CSEG
_main:
set1
_data1
;
Initialize by 1
clr1
_data2
;
Initialize by 0
L0003:
bf
_data1, $L0004
;
Judgment
mov1
CY, _data2
;
Assignment
mov1
_data1, CY
;
Assignment
call
!!_testb
br
$L0003
L0004:
bf
_data1, $L0005
;
Logical AND expression
bf
_data2, $L0005
;
Logical AND expression
call
!!_chgb
L0005:
L0006:
ret
END
COMPATIBILITY
From another C compiler to this C compiler
Modification is not required if the keyword bit, boolean, or _ _boolean is not used.
When changing variables to bit or boolean type variables, modify the program according to the method
above.
From this C compiler to another C compiler
#define must be used. For details, see 11.6 Modifications of C Source (As a result of this modification,
the bit or boolean type variables are handled as ordinary variables.).
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(8) _ _boolean1 type variables
_ _boolean1 type variables
_ _boolean1
FUNCTION
_ _boolean1 type variables are handled as 1-bit data and allocated to saddr1 area.
_ _boolean1 type variables are handled in the same manner as external variables without an initial value
(undefined).
The compiler outputs the following bit manipulation instructions for these bit variables.
MOV1, AND1, OR1, XOR1, SET1, CLR1, NOT1, BT, BF
instructions
EFFECT
Programming at the assembler source level and bit access to saddr1 area are enabled by C description.
USAGE
Declares _ _boolean1 type in the module that uses _ _boolean1 type variables.
_ _boolean1
variable-name
Declares the extern _ _boolean1 in the module that refers to _ _boolean1 type variables.
extern _ _boolean1
variable-name
The sreg1 variables (except the element of an array and member of a union) of char/int/short/long types are
automatically enabled to be used as _ _boolean1 type variables.
variables-name.n (n is 0 to 31)
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_ _boolean1 type variables
_ _boolean1
RESTRICTIONS
The operations between _ _boolean1 type variables can be performed using carry flags. Therefore, the
contents of the carry flag between statements are not guaranteed.
_ _boolean1 type variables cannot define/reference or array.
_ _boolean1 type variables cannot be used as a member of a structure or union.
_ _boolean1 type variables cannot be used as an argument type of a function.
_ _boolean1 type variables cannot be used as a return value of a function.
_ _boolean1 type variables cannot declare with an initial value.
If described with the const declaration, the const declaration is ignored.
Only operations using 0 and 1 can be performed by the operators and constants shown in the following table.
*, & (pointer reference, address reference), and sizeof operations cannot be performed.
Table 11-24. Operators That Use Only Constants 0 or 1 (When Using bit Type Variables)
Classification
Operator
Category
Operator
Assignment
=
AND in bit units
&, &=
OR in bit units
|, | =
XOR in bit units
^, ^
Logical AND
&&
Logical OR
||
Equal
==
Not equal
!=
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_ _boolean1 type variables
_ _boolean1
The following shows the number of usable _ _boolean1 type variables.
Table 11-25. Number of Usable _ _boolean1 Type Variables
Condition
Restrictions (Per Load Module)
When using saddr1 area [XFE00H to XFE7FH]
Max. 1024 variables can be used.
When sreg1 variables are used, however, the number of usable _ _boolean1 type variables is decreased.
EXAMPLE
(C source)
#define ON
1
#define OFF
0
extern void testb (void);
extern void chgb (void);
extern _ _boolean1 data1;
extern_ _boolean1 data2 ;
void main() {
data1 = ON;
data2 = OFF
while (data1) {
data1 = data2;
testb();
}
if (data1 && data2) {
chgb();
}
}
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_ _boolean1 type variables
_ _boolean1
(Assembler source)
Indicates the case where the user creates a definition code of a _ _boolean1 type variable. The following
example shows the case of the large model (-ML) and the location 0FH (-CS15). In this example, if the compiler
output section name @@ BITS1 is used, a link error occurs since the bit segment is changed to an AT attribute.
Therefore, other segment names should be used (if the attribute is saddr, the segment name @@BITS1 can be
used).
PUBLIC _data1
;
Declaration
PUBLIC _data2
BIT1_SEG BSEG
AT 0FFE00H
;
Allocation to segment
_data1 DBIT
_data2 DBIT
(Output object of compiler)
The compiler outputs the following codes if an extern declaration is not added. The following shows the case of
the large model.
EXTRN
_testb
EXTRN
_chgb
PUBLIC _data1
PUBLIC _data2
PUBLIC _main
@@BITS 1 BSEG SADDR
_data1 DBIT
_data2 DBIT
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_ _boolean1 type variables
_ _boolean1
(Output object of compiler...continued)
@@CODE CSEG
_main :
set1
_data1
;
Initialize by 1
clr1
_data2
;
Initialize by 0
L0003 :
bf
_data1, $L0004
;
Judgment
mov1
CY, _data2
;
Assignment
mov1
_data1, CY
;
Assignment
call
!!_testb
br
$L0003
L0004 :
bf
_data1, $L0005
;
Logical AND expression
bf
_data2, $L0005
;
Logical AND expression
call
!!_chgb
L0005 :
L0006 :
ret
END
COMPATIBILITY
From another C compiler to this C compiler
Modification is not required if the keyword _ _boolean1 is not used.
When changing to _ _boolean1 type variables, modify the program according to the method above.
From this C compiler to another C compiler
Changes are made by #define. For details, refer to 11.6 Modifications of C Source (by these changes,
_ _boolean1 type variables are handled as ordinary variables).
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(9) ASM statements
ASM Statements
#asm, #endasm
_ _asm
FUNCTION
(a) #asm - #endasm
The assembler source program described by the user can be embedded in an assembler source file to be
output by this C compiler by using the preprocessing directives #asm and #endasm.
#asm and #endasm lines will not be output.
(b) _ _asm
An assembly instruction is output and inserted in an assembler source by describing an assembly code for
a character string literal.
EFFECT
Global variables of the C source can be manipulated in the assembler source
Functions that cannot be described in the C source can be implemented
The assembler source output by the C compiler can be manually optimized and embeded it in the C source
(to obtain efficient objects)
USAGE
(a) #asm - #endasm
Indicate the start of the assembler source with the #asm directive and the end of the assembler source
with the #endasm directive. Describe the assembler source between #asm and #endasm.
#asm
:
/*
assembler source */
#endasm
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ASM Statements
#asm, #endasm
_ _asm
(b) _ _asm
Use of _ _asm is declared by the #pragma asm specification made at the beginning of the module in
which the ASM statement is to be described (the uppercase letters and lowercase letters are distinguished
for the keywords following #pragma).
The following items can be described before #pragma asm.
Comment
Other
#pragma directive
Preprocessing directive not creating variable definition/reference or function definition/reference
The ASM statement is described in the following format in the C source.
_ _asm (string literal);
The description method of the character string literal conforms to ANSI, and a line can be continued by using
an escape character string (\n: line feed, \t: tab) or , or character strings can be linked.
RESTRICTIONS
Nesting of #asm directives is not allowed.
If ASM statements are used, no object module file will be created. Instead, an assembler source file will be
created.
Only lowercase letters can be described for _ _asm. If _ _asm is described with uppercase and lowercase
characters mixed, it is regarded as a user function.
When the -ZA option is specified, only _ _asm is enabled.
#asm - #endasm and the _ _asm block can only be described inside a function of the C source. Therefore,
the assembler source is output to CSEG (with medium/large model) of the segment name @@CODE or
@@CODES CSEG BASE (with small model).
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ASM Statements
#asm, #endasm
_ _asm
EXAMPLE
(a) #asm - #endasm
(C source)
void main ( ) {
#asm
callt [60H]
#endasm
}
(Output object of compiler)
The assembler source written by the user is output to the assembler source file.
@@CODE CSEG
_main:
callt
[60H]
ret
END
EXPLANATION
In the above example, statements between #asm and #endasm will be output as an assembler source
program to the assembler source file.
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ASM Statements
#asm, #endasm
_ _asm
(b) _ _asm
(C source)
#pragma
asm
int a, b;
void main( ) {
_ _asm("\tmovw ax, !_a\t;ax <- a");
_ _asm("\tmovw !_b, ax\t;b <- ax");
}
(Assembler source)
@@CODE CSEG
_main:
movw ax, !_a
;ax <- a
movw !_b, ax
;b <- ax
ret
END
COMPATIBILITY
With a C compiler that supports #asm, modify the program according to the format specified by the C
compiler.
If the target device is different, modify the assembler source part of the program.
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(10) Interrupt functions
Interrupt Functions
#pragma vect
#pragma interrupt
FUNCTION
The address of a described function name is registered to an interrupt vector table corresponding to a
specified interrupt request name.
An interrupt function outputs a code to save or restore the following data (except that used in the ASM
statement) to or from the stack at the beginning and end of the function (after the code if a register bank is
specified).
(1)
Registers
(2)
saddr area for register variables
(3)
saddr2 area for arguments/auto variables of norec function (regardless of whether the arguments or
variables are used)
Note, however, that depending on the specification or status of the interrupt function, saving/restoring is
performed differently, as follows.
If no change is specified, codes that change the register bank or save/restore register contents, and that
save/restore the contents of the saddr2 area are not output regardless of whether the codes are used or not.
If a register bank is specified, a code to select the specified register bank is output at the beginning of the
interrupt function, therefore the contents of the registers are not saved or restored.
If "no change" is not specified and if a function is called in the interrupt function, however, the entire register
area is saved or restored, regardless of whether use of registers is specified or not.
If the -QR option is not specified during compilation, the saddr2 area for register variables and the saddr2
area for the arguments/auto variables of the norec function is not used; therefore, the saved/restored code is
not output.
If the size of the saved code is smaller than that of the restored code, the restored code is output.
Table 11-26 summarizes the above and shows the save/restore area.
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Interrupt Functions
#pragma vect
#pragma interrupt
Table 11-26. Save/Restore Area When Interrupt Function Is Used
Function Called
Function Not Called
Without -QR
With -QR
Without -QR
With -QR
Save/Restore Area
NO
BANK
Stack
RBn
Stack
RBn
Stack
RBn
Stack
RBn
Register used
All registers
saddr2 area for register variable used
Entire saddr2 area for argument/auto
variable of norec function
Stack: Use of stack is specified.
: Saved
RBn:
Register bank is specified.
: Not saved
Caution
If there is an ASM statement in an interrupt function, and if the area reserved for registers of the
compiler is used in that ASM statement, the area must be saved by the user.
EFFECT
Interrupt functions can be described at the C source level.
Because the register bank can be changed, codes that save the registers are not output; therefore, object
codes can be shortened and program execution speed can be improved.
You do not have to be aware of the addresses of the vector table to recognize an interrupt request name.
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Interrupt Functions
#pragma vect
#pragma interrupt
USAGE
Specify an interrupt request name, a function name, stock switching registers, and whether the saddr2 area is
saved/restored, with the #pragma directive. Describe the #pragma directive at the beginning of the C source.
The #pragma directive is described at the start of the C source (for the interrupt request names, refer to the
user's manual of the target device used). For the software interrupt BRK, describe BRK_I.
To describe #pragma PC (processor type), describe this #pragma directive after that. The following items
can be described before this #pragma directive.
Comment statements
Preprocessing directive that neither defines nor references a variable or a function
#pragma
vect (or interrupt) interrupt request name function name
[stack change specification]
stack use specification
no change specification
register bank specification
Interrupt request name:
Described in uppercase letters. Refer to the user's manual of the target
device used (example: NMI, INTP0, etc.).
For the software interrupt BRK, describe BRK_I.
Function name:
Name of the function that describes interrupt processing
Stack change specification:
SP = array name [+ offset location] (example: SP = buff + 10)
Define the array by unsigned char (example: unsigned char buff [10];).
Stack use specification:
STACK (default)
No change specification:
NOBANK
Register bank specification:
RB0/RB1/RB2/RB3/RB4/RB5/RB6/RB7
:
Space
Caution
The startup routine of this compiler is initialized to register bank 0. Therefore, specifying
register banks 1 to 7 is necessary.
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Interrupt Functions
#pragma vect
#pragma interrupt
RESTRICTIONS
An interrupt request name must be described in uppercase letters.
A duplication check on interrupt request names will be made within only one module.
If the same or another interrupt occurs because of the contents of the priority specification flag register and
interrupt mask flag register while a vectored interrupt is being processed, the contents of the registers may be
changed if a register bank is specified or no change is specified, resulting in an error. The compiler, however,
cannot check this error.
callt/callf/noauto/norec/_ _callt/_ _callf/_ _leaf/_ _rtos_interrupt/_ _pascal/_ _flash cannot be specified
as the interrupt function.
An interrupt function is specified with void type (example: void func (void);) because it cannot have an
argument or a return value.
Even if an ASM statement exists in the interrupt function, codes saving all the registers and variable areas are
not output. If an area reserved for the compiler is used in the ASM statement in the interrupt function,
therefore, or if a function is called in the ASM statement, the user must save the registers and variable areas
on their own responsibility.
If a function specifying no change, register bank, or stack change as the saving destination via a #pragma
vect/#pragma interrupt specification is not defined in the same module, a warning message is output and
the stack change is ignored. In this case, the default stack is used.
When stack change is specified, the stack pointer is changed to the location where offset is added to the array
name symbol. The area of the array name is not secured by the #pragma directive. It needs to be defined
separately as a global unsigned char type array.
The code that changes the stack pointer is generated at the start of a function, and the code that sets the
stack pointer back is generated at the end of a function.
When the keywords sreg/_ _sreg are added to the array for stack change, it is regarded that two or more
variables with the different attributes and the same name are defined, and a compilation error occurs. It is
possible to allocate an array in saddr area using the -RD option, but code and speed efficiency will not be
improved because the array is used as a stack. It is recommended to use the saddr area for purposes other
than a stack.
A stack change cannot be specified simultaneously with "no change". If specified so, an error occurs.
The stack change must be described before the stack use/register bank specification. If the stack change is
described after the stack use/register bank specification, an error occurs.
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Interrupt Functions
#pragma vect
#pragma interrupt
EXAMPLE
(C source 1)
#pragma interrupt NMI inter rb1
void inter()
{
/*
interrupt handling to NMI pin input */
}
(Output object of compiler)
@@BASE CSEG BASE
_inter:
Register bank switching code
Save code of saddr area for use by C compiler
Interrupt handling to NMI input (function body)
Restore code of saddr area for use by C compiler
reti
@@VECT02 CSEG AT 02H ; NMI
DW _inter
(C source 2)
(When stack change and register bank are specified)
#pragma interrupt INTP0 inter sp=buff+10 rb2
unsigned char buff[10];
void func();
void inter();
{
func();
}
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Interrupt Functions
#pragma vect
#pragma interrupt
(Output object of compiler) With large model
@@BASE
CSEG
BASE
_inter:
sel
RB2
;
Changes register bank
push
whl
;
movg
whl,sp
;
Changes stack pointer
movg
sp,#_buff+10
;
push
whl
;
call
!!_func
pop
whl
;
movg
sp,whl
;
Sets back stack pointer
pop
whl
;
reti
@@VECT06 CSEG AT 0006H
DW _inter
COMPATIBILITY
From another C compiler to this C compiler
Modification is not required if interrupt functions are not used at all.
When changing an ordinary function to an interrupt function, modify the program according to the method
above.
From this C compiler to another C compiler
An interrupt function can be used as an ordinary function by deleting its specification with the #pragma
vect, #pragma interrupt directive.
When an ordinary function is to be used as an interrupt function, change the program according to the
specifications of each compiler.
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(11) Interrupt function qualifier (_ _interrupt, _ _interrupt_brk)
Interrupt Function Qualifier
_ _interrupt
_ _interrupt_brk
FUNCTION
A function declared with the _ _interrupt qualifier is regarded as a hardware interrupt function, and execution
is returned by the return RETI instruction for non-maskable/maskable interrupt functions.
By declaring a function with the _ _interrupt_brk qualifier, the function is regarded as a software interrupt
function, and execution is returned by the return instruction RETB for software interrupt functions.
A function declared with this qualifier is regarded as a (non-maskable/maskable/software) interrupt function,
and saves or restores the registers and variable areas (1) and (3) below, which are used as the work area of
the compiler, to or from the stack.
If a function call is described in this function, however, all the variable areas are saved to the stack.
(1) Registers
(2) saddr area for register variables
(3) saddr area for arguments/auto variables of norec function (regardless of usage)
Remark
If the -QR option is not specified (default) during compilation, codes to save or restore areas (2) and (3)
are not output because these areas are not used.
EFFECT
By declaring a function with this qualifier, the setting of a vector table and interrupt function definition can be
described in separate files.
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Interrupt Function Qualifier
_ _interrupt
_ _interrupt_brk
USAGE
Describe either _ _interrupt or _ _interrupt_brk as the qualifier of an interrupt function.
(For non-maskable/maskable interrupt function)
_ _interrupt void func() {
processing}
(For software interrupt function)
_ _interrupt_brk void func() {
processing}
RESTRICTIONS
callt/callf/noauto/norec/_ _callt/_ _callf/_ _leaf/_ _rtos_interrupt/_ _pascal/_ _flash cannot be specified
for the interrupt function.
CAUTIONS
The vector address is not set by merely declaring this qualifier. The vector address must be separately set by
using the #pragma vect/interrupt directive or assembler description.
The saddr area and registers are saved to the stack.
Even if the vector address is set or the saving destination is changed by #pragma vect (or interrupt) ..., the
change in the saving destination is ignored if there is no function definition in the same file, and the default
stack is assumed.
To define an interrupt function in the same file as the #pragma vect (or interrupt) ... specification, the
function name specified by #pragma vect (or interrupt) ... is judged as the interrupt function, even if this
qualifier is not described (for details of #pragma vect/interrupt, refer to 11.5 (10) Interrupt functions).
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Interrupt Function Qualifier
_ _interrupt
_ _interrupt_brk
EXAMPLE
Declare or define interrupt functions in the following format. The code to set the vector address is generated by
#pragma interrupt.
#pragma interrupt INTP0 inter RB1
#pragma interrupt BRK_I inter_b RB2
/*
Note */
_ _interrupt void inter( );
/*
prototype declaration */
_ _interrupt_brk void inter_b( );
/*
prototype declaration */
_ _interrupt void inter( ) {processing};
/*
function body */
_ _interrupt_brk void inter_b( ) {processing};
/*
function body */
Note
The interrupt request name of the software interrupt is "BRK_I."
COMPATIBILITY
From another C compiler to this C compiler
Modification is not required unless interrupt functions are supported.
Modify the interrupt functions, if necessary, according to the method above.
From this C compiler to another C compiler
#define must be used to allow the interrupt qualifiers to be handled as ordinary functions.
To use the interrupt qualifiers as interrupt functions, modify the program according to the specifications of
each compiler.
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(12) Interrupt functions
Interrupt Functions
#pragma DI
#pragma EI
FUNCTIONS
Codes DI and EI are output to an object and an object file is created.
If the #pragma directive is missing, DI( ) and EI( ) are regarded as ordinary functions.
If "DI( );" is described at the beginning in a function (except for the declaration of an automatic variable, a
comment, or a preprocessing directive), the DI code is output before the preprocessing of the function
(immediately after the label of the function name).
To output the code of DI after the preprocessing of the function, open a new block before describing "DI( );"
(delimit this block with `{`).
If "EI( );" is described at the end of a function (except for comments and preprocessing directives), the EI
code is output after the postprocessing of the function (immediately before the code RET).
To output the EI code before the postprocessing of a function, close a new block after describing "EI( );"
(delimit this block with `}').
EFFECT
A function disabling interrupts can be created.
USAGE
Describe the #pragma DI and #pragma EI directives at the beginning of the C source. However, the
following statement and directives may precede the #pragma DI and #pragma EI directives.
Comment statement
Other #pragma directives
Preprocessing directive that neither defines nor references a variable or function
Describe DI( ); or EI( ); in the source in the same manner as a function call.
DI and EI can be described in either uppercase or lowercase letters after #pragma.
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Interrupt Functions
#pragma DI
#pragma EI
RESTRICTIONS
When using these interrupt functions, DI and EI cannot be used as function names.
DI and EI must be described in uppercase letters. If described in lowercase letters, they will be handled as
ordinary functions.
EXAMPLE
(C source 1)
#pragma DI
#pragma EI
void main ()
{
DI ();
Function body
EI ();
}
(Output object of compiler)
_main:
di
Preprocessing
Function body
Postprocessing
ei
ret
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Interrupt Functions
#pragma DI
#pragma EI
<To output DI after preprocessing and EI before postprocessing>
(C source 2)
#pragma DI
#pragma EI
void main ()
{
{
DI();
Function body
EI();
}
}
(Output object of compiler)
_main:
Preprocessing
di
Function body
ei
Postprocessing
ret
COMPATIBILITY
From another C compiler to this C compiler
Modification is not required if interrupt functions are not used at all.
When changing an ordinary function to an interrupt function, modify the program according to the method
above.
From this C compiler to another C compiler
Delete the #pragma DI and #pragma EI directives or invalidate these directives by separating them with
#ifdef. DI and EI can be used as ordinary function names (example: #ifdef_ _K4_ _ ... #endif).
When an ordinary function is to be used as an interrupt function, modify the program according to the
specifications of each compiler.
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(13) CPU control instruction
CPU Control Instructions
#pragma HALT/STOP/BRK/NOP
FUNCTION
The following codes are output to an object to create an object file.
(1)
Instruction for HALT operation
Note 1
(2)
Instruction for STOP operation
Note 2
(3)
BRK instruction
(4)
NOP instruction
Notes 1.
The setting of STOP mode and selection of the internal system clock is possible using the STBC
register. The C compiler reads STBC, checks the CK1/CK0 value of the internal system clock
selection, and accordingly outputs the instruction to set the value for HALT to STBC.
2.
The C compiler reads STBC, checks the CK1/CK0 value of the internal system clock selection, and
accordingly outputs the instruction to set the value for STOP to STBC.
EFFECT
The standby function of a microcontroller can be used with a C program.
A software interrupt can be generated.
The clock can continue without the CPU operating.
USAGE
Describe the #pragma HALT, #pragma STOP, #pragma NOP, and #pragma BRK instructions at the
beginning of the C source.
The following items can be described before the #pragma directive.
Comment statement
Other #pragma directive
Preprocessing directive that neither defines nor references a variable or function
The keywords following #pragma can be described in either uppercase or lowercase letters.
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CPU Control Instructions
#pragma HALT/STOP/BRK/NOP
Describe as follows in uppercase letters in the C source in the same format as a function call.
(1) HALT();
(2) STOP();
(3) BRK();
(4) NOP();
RESTRICTIONS
When this feature is used, HALT( ), STOP( ), BRK( ), and NOP( ) cannot be used as function names.
Describe HALT, STOP, BRK, and NOP in uppercase letters. If they are described in lowercase letters, they
are handled as ordinary functions.
EXAMPLE
(C source)
#pragma HALT
#pragma STOP
#pragma BRK
#pragma NOP
void main()
{
HALT();
STOP();
BRK();
NOP();
}
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CPU Control Instructions
#pragma HALT/STOP/BRK/NOP
(Output object of compiler) With large model
@@CODE
CSEG
_main :
; line
7 :
HALT();
mov
a,STBC
bt
a,4,$$+12
bt
a.5,$$+24
mov
STBC,#01H
br
$$+21
bt
a.5,$$+9
mov
STBC,#011H
br
$$+12
mov
STBC,#031H
br
$$+6
mov
STBC,#021H
; line
8 :
STOP() ;
mov
a,STBC
bt
a.4,$$+12
bt
a.5,$$+24
mov
STBC,#02H
br
$$+21
bt
a.5,$$+9
mov
STBC,#012H
br
$$+12
mov
STBC,#032H
br
$$+6
mov
STBC,#022H
; line
9 :
BRK() ;
brk
; line
10 :
NOP() ;
nop
ret
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CPU Control Instructions
#pragma HALT/STOP/BRK/NOP
COMPATIBILITY
From another C compiler to this C compiler
Modification is not required if the CPU control instructions are not used.
When the CPU control instructions are used, modify the program according to the method above.
From this C compiler to another C compiler
If "#pragma HALT", "#pragma STOP", "#pragma BRK", and "#pragma NOP" statements are deleted or
delimited with #ifdef, HALT, STOP, BRK, and NOP can be used as function names.
To use these instructions as CPU control instructions, modify the program according to the specifications
of each compiler.
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(14) callf functions
callf Functions
callf/_ _callf
FUNCTION
The callf instruction stores the body of a function in the callf area. This makes code shorter than ordinary call
instructions.
If a function stored in the callf area is to be referenced without a prototype declaration, the function must be
called by an ordinary call instruction.
The callee (the function to be called) is the same as an ordinary function.
EFFECT
The object code can be shortened.
USAGE
Add the callf attribute or _ _callf attribute to the beginning of a function at the time of the function declaration
as follows.
callf extern
type-name function-name
_ _callf extern
type-name function-name
RESTRICTIONS
Functions declared with callf will be located in the callf entry area. At which address in the area each
function is to be located will be determined at the time of linking object modules. For this reason, when using
any callf function in an assembler source module, the routine to be created must be made "relocatable" using
symbols.
A check on the number of callf functions is made at linking time.
callf entry area: 800H to FFFH
The number of functions that can be declared with the callf attribute is not limited.
The total number of functions with the callf attribute is not limited as long as the first function is within the
range of [800H to FFFH].
When the -ZA option is specified, only _ _callf is enabled.
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callf Functions
callf/_ _callf
EXAMPLE
(C source 1)
(C source 2)
(Output object of compiler) With large model
<C source 1>
EXTRN _fsub
;
Declaration
Callf !_fsub
;
Call
<C source 2> (to be allocate to callf entry area)
PUBLIC _fsub
;
Declaration
@@CALF
CSEG
FIXED
_fsub:
;
Function definition
:
Function body
:
COMPATIBILITY
From another C compiler to this C compiler
Modification is not required if the keyword callf/_ _callf is not used.
When changing functions to callf functions, modify the program according to the method above.
From this C compiler to another C compiler
#define must be used to allow callf functions to be handled as ordinary functions.
_ _callf extern int fsub();
void main ()
{
int ret_val;
ret_val = fsub();
}
_ _callf int fsub()
{
int val;
return val;
}
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(15) 16 MB expansion space utilization
16 MB Expansion Space Utilization
16 MB expansion -ML
FUNCTION
An object file that can linearly access a 16 MB expansion space is created.
EFFECT
The 16 MB expansion space can be accessed in the same manner as 16-bit addressing (64 KB) mode.
USAGE
Specify the -ML option (default) during compilation.
RESTRICTIONS
When the -MS option is specified at the time of startup:
Small model: Combined code/data block capacity of 16 KB
When the -MM option is specified at the time of startup:
Medium model: Capacity of up to 1 MB for the code block and 16 KB for the data block
When the -ML option is specified at the time of startup:
Large model: Combined code/data block capacity of 16 MB, including up to 1 MB for the code block and 16
MB for the data block.
EXAMPLE
(C source)
sreg int *ladr;
int *grob;
void main ( ) {
int atval;
*ladr = atval;
*grob = atval;
}
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16 MB Expansion Space Utilization
16 MB expansion -ML
(Output object of compiler)
With small model
@@CODES
CSEG
BASE
_main :
push
rp3
;
Preprocessing of function
movw
ax,rp3
movw
[_ladr],ax
;
*ladr = atval
movw
hl,!_grob
movw
ax,rp3
movw
[hl],ax
;
*grob = atval
pop
rp3
;
Postprocessing of function
ret
With medium model
@@CODE CSEG
_main:
push
rp3
;
Preprocessing of function
movw
de,_ladr
movw
ax,rp3
movw
[de],ax
;
*ladr = atval
movw
de,!!_grob
movw
ax,rp3
movw
[de],ax
;
*grob = atval
pop
rp3
;
Postprocessing of function
ret
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16 MB Expansion Space Utilization
16 MB expansion -ML
(Output object of compiler)
With large model
@@CODE
CSEG
_main :
push
rp3
;
Preprocessing of function
movw
ax,rp3
movw
[%_ladr],ax
;
*ladr = atval
movg
whl,!!_grob
movw
[hl],ax
;
*grob = atval
pop
rp3
;
Postprocessing of function
ret
COMPATIBILITY
From another C compiler to this C compiler
Modification is not required if it has been re-compiled with the -ML option added during compilation, when
the 16 MB expansion space is to be used.
From this C compiler to another C compiler
The source program need not be modified if it is re-compiled with each compiler.
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(16) Allocation function
Allocation Function
Allocation function -CS
FUNCTION
With the medium model (when the -MM option is specified) or with the large model (when the -ML option is
specified), the allocation of the saddr area can be changed by using the -CS option.
EFFECT
When the -CS15 option is specified, the code space can be continuously used.
USAGE
The -CS option is specified during compilation.
The -CS option performs the following operation.
-CS0
:
Allocates saddr area to 0FD20H to 0FFFFH
-CS15/-CS0FH
:
Allocates saddr area to 0FFD20H to 0FFFFFH
-CSA
:
Does not check with compiler but with linker
RESTRICTIONS
Use the startup routine included with to this compiler that specifies the location specified by the -CS option.
The LOCATION instruction is described in the startup routine (for details of the startup routine, refer to the
CC78K4 C Compiler Operation User's Manual (U15557E)).
EXAMPLE
(C source)
void main ( ) {
/*
function body */
}
(Output object of compiler)
With large model (-ML) and location 0 (-CS0) specified
$CHGSFR (0)
$PROCESSOR(4026)
;
Variable declaration etc.
@@CODE
CSEG
_main:
;
Function preprocessing
;
Function body processing
;
Function postprocessing
ret
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Allocation Function
Allocation function -CS
With large model (-ML) and location 15 (-CS15) specified
$CHGSFR (15)
$PROCESSOR 4026)
;
Variable declaration etc.
@@CODE
CSEG
_main:
;
Function preprocessing
;
Function body processing
;
Function postprocessing
ret
With large model (-ML) and without compile check (-CSA) specified
$CHGSFRA
$PROCESSOR(4026)
;
Variable declaration etc.
@@CODE
CSEG
_main:
;
Function preprocessing
;
Function body processing
;
Function postprocessing
ret
COMPATIBILITY
From another C compiler to this C compiler
When using the medium model or large model, modification is not required if the location position is
specified by the -CS option during compilation and the source program is re-compiled.
From this C compiler to another C compiler
The source program need not be modified if it is re-compiled with each compiler.
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(17) Absolute address access function
Absolute Address Access Function
#pragma access
FUNCTION
A code to access the ordinary RAM space is output to the object with direct inline expansion, not by function
call, and an object file is created.
If the #pragma directive is not described, a function accessing an absolute address is regarded as an
ordinary function.
EFFECT
A specific address in the ordinary memory space can be easily accessed using C description.
USAGE
Describe the #pragma access directive at the beginning of the C source.
Describe the directive in the source in the same format as a function call.
The following items can be described before #pragma access.
.
Comment statement
.
Other #pragma directives
.
Preprocessing directive that neither defines nor references a variable or function
The keywords following #pragma can be described in either uppercase or lowercase letters.
The following four function names are available for absolute address accessing.
peekb, peekw, pokeb, pokew
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Absolute Address Access Function
#pragma access
[List of functions for absolute address accessing]
(a) unsigned char peekb (addr);
unsigned int addr;
(small model)
unsigned long addr;
(medium model/large model)
Returns 1-byte contents of address addr.
(b) unsigned int peekw (addr);
unsigned int addr;
(small model)
unsigned long addr;
(medium model/large model)
Returns 2-byte contents of address addr.
(c) void pokeb (addr, data);
unsigned int addr;
(small model)
unsigned long addr;
(medium model/large model)
unsigned char data;
Writes 1-byte contents of data to the position indicated by address addr.
(d) void pokew (addr, data);
unsigned int addr;
(small model)
unsigned long addr;
(medium model/large model)
unsigned int data;
Writes 2-byte contents of data to the position indicated by address addr.
RESTRICTIONS
A function name for absolute address accessing must not be used.
Describe functions for absolute address accessing in lowercase letters. Functions described in uppercase
letters are handled as ordinary functions.
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Absolute Address Access Function
#pragma access
EXAMPLE
(C source)
#pragma access
char a;
int b;
void main ()
{
a = peekb(0x1234);
a = peekb(0xfe23);
b = peekw(0x1256);
b = peekw(0xfe68);
pokeb(0x1234, 5);
pokeb(0xfe23, 5);
pokew(0x1256, 100);
pokew(0xfe68, 100);
}
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Absolute Address Access Function
#pragma access
(Output object of compiler)
With large model
@@CODE CSEG
-main:
mov
a, !01234H
mov
!!_a,a
mov
a, !0FE23H
mov
!!_a,a
movw
ax, !01256H
movw
!!_b,ax
movw
ax, 0FE68H
movw
!!_b,ax
mov
a, #05H ;5
mov
!01234H,a
mov
!0FE23H,a
movw
ax, #064H
;100
movw
!01256H,ax
movw
!0FE68H,ax
ret
COMPATIBILITY
From another C compiler to this C compiler
Modification is not required if a function for absolute address accessing is not used.
Modify the program according to the method above if a function for absolute address accessing is used.
From this compiler to another C compiler
Delete the "#pragma access" statement or delimit with #ifdef. The function name of absolute address
accessing can be used as a function name.
When using a function for absolute address accessing, modify the program according to the specifications
of each compiler (#asm, #endasm, asm( );,etc.)
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(18) Bit field declaration
Bit Field Declaration
Bit field declaration
(1) Extension of type specifier
FUNCTION
The bit field of unsigned char type is not allocated straddling over a byte boundary.
The bit field of unsigned int type is not allocated straddling over a word boundary, but can be allocated
straddling over a byte boundary.
The bit fields of the same type are allocated in the same byte units (or word units). If the types are different,
the bit fields are allocated in different byte units (or word units).
EFFECT
The memory can be saved, the object code can be shortened, and the execution speed can be improved.
USAGE
As a bit field type specified, unsigned char type can be specified in addition to unsigned int type. Declare as
follows.
struct
tag-name {
unsigned char
field-name: bit-width;
unsigned char
field-name: bit-width;
:
unsigned int
field-name: bit-width;
};
EXAMPLE
struct
tagname {
unsigned char A:1;
unsigned char B:1;
:
unsigned int C:2;
unsigned int D:1;
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Bit Field Declaration
Bit field declaration
COMPATIBILITY
From another C compiler to this C compiler
Modification is not required.
Change the type specifier to use unsigned char as the type specifier.
From this C compiler to another C compiler
Modification is not required if unsigned char is not used as a type specifier.
Change unsigned char, if it is used as a type specifier, to unsigned int.
(2) Allocation direction of bit field
FUNCTION
The direction in which a bit field is to be allocated is changed and the bit field is allocated from the MSB side
when the -RB option is specified.
If the -RB option is not specified, the bit field is allocated from the LSB side.
USAGE
The -RB option is specified during compilation to allocate the bit field from the MSB side.
Do not specify the option to allocate the bit field from the LSB side.
EXAMPLE 1
(Bit field declaration)
struct t {
unsigned char a:1;
unsigned char b:1;
unsigned char c:1;
unsigned char d:1;
unsigned char e:1;
unsigned char f:1;
unsigned char g:1;
unsigned char h:1;
};
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Bit Field Declaration
Bit field declaration
EXPLANATION
Because a through h are 8 bits or less, they are allocated in 1-byte units.
If the bit field is allocated to saddr2 or saddr1 area by the keywords sreg/_ _sreg/_ _sreg1, a bit manipulation
instruction is output, and codes can be reduced.
Figure 11-1. Bit Allocation by Bit Field Declaration (Example 1)
Bit allocation from MSB
with -RB option specified
Bit allocation from LSB
without -RB option specified
MSB
LSB
MSB
LSB
a
b
c
d
e
f
g
h
h
g
f
e
d
c
b
a
EXAMPLE 2
(Bit field declaration)
struct t {
char
a;
unsigned char b:2;
unsigned char c:3;
unsigned char d:4;
Int e;
unsigned int f:5;
unsigned int g:6;
unsigned char h:2;
unsigned int i:2;
};
EXPLANATION
If the bit field is allocated to saddr2 or saddr1 area by the keywords sreg/_ _sreg/_ _sreg1, the code efficiency
can be improved.
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Bit Field Declaration
Bit field declaration
Figure 11-2. Bit Allocation by Bit Field Declaration (Example 2) (1/2)
Bit allocation from MSB
with -RB option specified
Bit allocation from LSB
without -RB option specified
MSB
LSB
b
c
Vacant
a
1
0
Member a of char type is allocated to the first byte unit. b and c are allocated from the next byte unit. If the
vacancy has run short, the members are allocated to the next byte unit. Because the vacancy is 3 bits and d is 4
bits in this example, d is allocated to the next byte unit.
e
d
Vacant
3
2
g
Vacant
e
5
4
The 78K/IV Series has 1-byte alignment; therefore, e (2 bytes) can straddle over a byte boundary.
h
Vacant
f
g
7
6
Because g is an unsigned int type bit field, it can be allocated across byte boundary. h is an unsigned char
type bit field; it is therefore allocated to the next byte unit, instead to the same byte unit as g, which is an
unsigned int type bit field.
h
Vacant
Vacant
9
8
i is an unsigned int type bit field and can be allocated to the next word unit.
Remark The numbers below the allocation diagrams indicate the byte offset values from the beginning of the
structure.
MSB
LSB
Vacant
c
b
a
1
0
e
Vacant
d
3
2
g
f
e
5
4
Vacant
h
Vacant
g
7
6
Vacant
Vacant
i
9
8
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Bit Field Declaration
Bit field declaration
When the -RA option or -RP option is specified, the bit field is made 2-byte alignment. The location of the bit
field above is as follows.
Figure 11-2. Bit Allocation by Bit Field Declaration (Example 2) (2/2)
Bit allocation from MSB
with -RB option specified
Bit allocation from LSB
without -RB option specified
MSB
LSB
b
c
Vacant
a
1
0
e
d
Vacant
3
2
e
e
5
4
f
g
g
Vacant
7
6
Vacant
h
Vacant
9
8
i
Vacant
Vacant
11
10
MSB
LSB
Vacant
c
b
a
1
0
Vacant
Vacant
d
3
2
e
e
5
4
Vacant
g
g
f
7
6
Vacant
Vacant
h
9
8
Vacant
Vacant
i
11
10
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Bit Field Declaration
Bit field declaration
EXAMPLE 3
(Bit field declaration)
struct
char
a;
unsigned int
b:6;
unsigned int
c:7;
unsigned int
d:4;
unsigned char
e:3;
unsigned int
f:10;
unsigned int
g:2;
unsigned int
h:5;
unsigned int
i:6;
};
Figure 11-3. Bit Allocation by Bit Field Declaration (Example 3) (1/2)
Since b and c are bit fields of type unsigned int, they are allocated from the next word unit.
Since d is also a bit field of type unsigned int, it is allocated from the next word unit.
Vacant
d
e
Vacant
e
Vacant
Vacant
Since e is a bit field of type unsigned char, it is allocated to the next byte unit.
MSB
LSB
c
Vacant
b
c
Vacant
a
c
b
a
d
Vacant
Vacant
c
MSB
LSB
Bit allocation from MSB
with RB option specified
Bit allocation from LSB
without RB option specified
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Bit Field Declaration
Bit field declaration
Figure 11-3. Bit Allocation by Bit Field Declaration (Example 3) (2/2)
f and g, and h and i are each allocated to separate word units.
When the RA option or RP option is specified, the bit field is made 2-byte alignment. The location of the bit
field above is as follows.
a
Vacant
a
Vacant
c
Vacant
Vacant
d
Vacant
d
d
Vacant
Vacant
e
Vacant
Vacant
c
b
c
Vacant
e
Vacant
Vacant
f
f
g
Vacant
Vacant
g
f
f
i
i
h
h
i
i
Vacant
Vacant
Remark
The numbers below the allocation diagrams indicate the byte offset values from the beginning of the
structure.
f
f
g
Vacant
h
f
f
g
Vacant
i
i
Vacant
Vacant
i
i
h
MSB
LSB
MSB
LSB
Bit allocation from MSB
with RB option specified
Bit allocation from LSB
without RB option specified
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Bit Field Declaration
Bit field declaration
COMPATIBILITY
From another C compiler to this C compiler
Modification is not required.
From this C compiler to another C compiler
Modification is required if the -RB option is used and coding is performed taking the bit field allocation
sequence into consideration.
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(19) Changing compiler output section name
#pragma section...
#pragma section
FUNCTION
A compiler output section name is changed and a start address is specified. If the start address is omitted,
the default allocation is assumed. For the compiler output section name and default location, refer to
APPENDIX B LIST OF SEGMENT NAMES. In addition, the location of sections can be specified by omitting
the start address and using the link directive file at the time of link. For the link directives, refer to the
RA78K4 Assembler Package Operation User's Manual.
To change section names @@CALT and @@CALF with an AT start address specified, the callt and callf
functions must be described before or after the other functions in the source file.
If data is described after the #pragma directive is described, that data is located in the data change section.
Another change instruction is possible, and if data is described after the rechange instruction, that data is
located in the rechange section. If data defined before a change is redefined after the change, it is located in
the rechanged section. Note that this is valid in the same way for static variables (within the function).
EFFECT
Changing the compiler output section repeatedly in one file enables location of each section independently, so
that data can be located independently in the desired data unit.
USAGE
Specify the name of the section to be changed, a new section name, and the start address of the section, by
using the #pragma directive as indicated below.
Describe this #pragma directive at the beginning of the C source.
Describe this #pragma directive after #pragma PC (processor type).
The following items can be described before this #pragma directive.
Comment statement
Preprocessing directive that neither defines nor references a variable or a function
However, all the sections in BSEG and DSEG, and the @@CNST, @@CNSTS and @@CNSTM sections in
CSEG can be described anywhere in the C source, and rechange instructions can be performed repeatedly. To
return to the original section name, describe the compiler output section name in the changed section name.
Declare as follows at the beginning of the file.
#pragma section
compiler-output-section-name new section-name [AT start address]
Of the keywords to be described after #pragma, be sure to describe the compiler output section name in
uppercase letters. section, AT can be described in either uppercase or lowercase letters, or in a combination
of these.
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#pragma section...
#pragma section
The format in which the new section name is to be described conforms to the assembler specifications (up to
eight letters can be used for a segment name).
Only the hexadecimal numbers of the C language and the hexadecimal numbers of the assembler can be
described as the start address.
[Hexadecimal numbers of C language]
0xn / 0xn...n
0Xn / 0xn...n
(n = 0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F)
[Hexadecimal numbers of assembler]
nH/n...nH
nh/n...nh
(n = 0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F)
The hexadecimal number must start with a numeral.
Example
To express a numeric value with a value of 255 in hexadecimal numbers, specify zero before F.
It is therefore 0FFH.
When the -QR option is not specified, the start address specification is within the following range.
0XFE2C to 0XFE7F
For sections other than the @@CNST, @@CNSTS and @@CNSTM sections in CSEG, that is, sections
which locate functions, this #pragma directive cannot be described at other than the beginning of the C
source (after the C text is described). If described, it causes an error.
If this #pragma directive is executed after the C text is described, an assembler source file is created without
an object module file being created.
If this #pragma directive is described after the C text is described, a file that contains this #pragma directive
and that does not have the C text (including external reference declarations for variables and functions)
cannot be included. This results in an error (refer to ERROR DESCRIPTION EXAMPLE 1).
An #include statement cannot be described in a file that executes this #pragma directive following the C text
description. If described, it causes an error (refer to ERROR DESCRIPTION EXAMPLE 2).
If #include statement follows the C text, this #pragma directive cannot be described after this description. If
described, it causes an error. (Refer to ERROR DESCRIPTION EXAMPLE 3).
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#pragma section...
#pragma section
EXAMPLE 1
Section name @@CODE is changed to CC1 and address 2400H is specified as the start address.
(C source)
#pragma section @@CODE CC1 AT 2400H
void main()
{
Function body
}
(Output object)
CC1
CSEG
AT
2400H
_main:
Preprocessing
Function body
Postprocessing
ret
EXAMPLE 2
This example shows a description in which this #pragma directive is described following the C text. The
statement beginning with the double slashes (//) indicates the section to be located.
#pragma section @@DATA ??DATA
int a1;
// ??DATA
_sreg int b1;
// @@DATS
int c1 = 1;
// @@INIT and @@R_INIT
const int d1 = 1;
// @@CNST
#pragma section @@DATS ??DATS
int a2;
// ??DATA
_sreg int b2;
// ??DATS
int c2 = 2;
// @@INIT and @@R_INIT
const int d2 = 2;
// @@CNST
#pragma section @@DATA ??DATA2
// ??DATA is closed automatically and ??DATA2 becomes valid.
int a3;
// ??DATA2
_sreg int b3;
// ??DATS
int c3 = 3;
// @@INIT and @@R_INIT
const int d3 = 3;
// @@CNST
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#pragma section...
#pragma section
#pragma section @@DATA @@DATA
// ??DATA2 is closed and processing returns to the default
// @@DATA.
#pragma section @@INIT ??INIT
#pragma section @@R_INIT ??R_INIT
//If both names @@INIT and @@R_INIT are not changed,
// ROMization becomes invalid.
int a4;
// @@DATA
_sreg int b4;
// ??DATS
int c4 = 4;
// ??INIT and ??R_INIT
const int d4 = 4;
// @@CNST
#pragma section @@INIT @@INIT
#pragma section @@R_INIT @@R_INIT
// ??INIT and ??R_INIT are closed and return to the defaults
#pragma section @@BITS ??BITS
_boolean e4;
// ??BITS
#pragma section @@CNST ??CNST
char*const p = "Hello";
// both p and "Hello" ??CNST
EXAMPLE 3
#pragma section @@INIT ??INIT1
#pragma section @@R_INIT ??R_INT1
#pragma section @@DATA ??DATA1
char c1;
int i2;
#pragma section @@INIT ??INIT2
#pragma section @@R_INIT ??R_INT2
#pragma section @@DATA ??DATA2
char c1;
int i2 = 1;
#pragma section @@DATA ??DATA3
#pragma section @@INIT ??INIT3
#pragma section @@R_INIT ??R_INT3
extern char c1;
// ??DATA3
int i2;
// ??INIT3 and ??R_INT3
#pragma section @@DATA ??DATA4
#pragma section @@INIT ??INIT4
#pragma section @@R_INIT ??R_INT4
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#pragma section...
#pragma section
EXAMPLE 4
(Method to specify the location of a section by link directives)
1.
Change the section name whose location is to be changed in the C source.
(In this example, @@DATA is changed to DAT1, and @@INIT is changed to DAT2)
(C source)
#pragma section @@DATA DAT1
#pragma section @@INIT DAT2
unsigned int d1,d2,d3;
unsigned long l1, l2;
unsigned int i =1;
:
(Output object of compiler)
@@R_INT
CSEG
;
DW
01H
;1
DAT2
DSEG
_I :
DS
(2)
DAT1
DSEG
_d1 :
DS
(2)
_d2 :
DS
(2)
_d3:
DS
(2)
_l1 :
DS
(4)
_l2 :
DS
(4)
2.
Create a link directive file.
(Link directive file lk78k4.job)
memory EXTRAM1:(0F0000h , 01000h)
memory EXTRAM2:(0F1000h , 01000h)
:
merge DAT1 : = EXTRAM1
merge DAT2 : AT(0F1000h) = EXTRAM2
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#pragma section...
#pragma section
3.
Link by specifying the link directive file using the linker option -D.
> lk78k4 s4.rel sample.rel -BCl4.lib -Dlk78k4.job -S
The following example explains the restrictions on describing this #pragma directive following the C text.
ERROR DESCRIPTION EXAMPLE 1
a1.h
#pragma section @@DATA ??DATA1
// File with a #pragma section only.
a2.h
extern int func1 (void);
#pragma section @@DATA ??DATA2
// File where there is C text and this #pragma directive follows
// after.
a3.h
#pragma section @@DATA ??DATA3
// File with a #pragma section only.
a4.h
#pragma section @@DATA ??DATA3
extern int func2 (void);
// File that includes C text.
a.c
#include "a1.h"
#include "a2.h"
#include "a3.h"
//
Error.
// There is C text in a2.h and after that this #pragma directive is
// included, so the file that includes this #pragma directive only, //
a3.h, cannot be included.
#include "a4.h"
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#pragma section...
#pragma section
ERROR DESCRIPTION EXAMPLE 2
b1.h
const int i;
b2.h
const int j;
#include "b1.h"
// There is C text and there is no file (b.c) where this #pragma
// directive is executed after it, so there is no error.
b.c
const int k;
#pragma section @@DATA ??DATA1
#include "b2.h"
//
Error.
// There is C text, and in the file following it where this #pragma
// directive is executed (b.c), a subsequent #include statement
// cannot be described.
ERROR DESCRIPTION EXAMPLE 3
c1.h
extern int j;
#pragma section @@DATA ??DATA1
// This #pragma directive is included and processed before c3.h
processing, so there is
// no error.
c2.h
extern int k;
#pragma section @@DATA ??DATA2
//
Error.
// There is C text in c3.h and after that there is an #include
// statement, so this #pragma directive cannot be included after
// that.
c3.h
#include "c1.h"
extern int i;
#include "c2.h"
#pragma section @@DATA ??DATA3
//
Error.
// There is C text, and after that there is an #include statement, so
// this #pragma directive cannot be included after that.
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#pragma section...
#pragma section
c.c
#include "c3.h"
#pragma section @@DATA??DATA4
//
Error.
// There is C text in c3.h and after that there is an #include
// statement, so this #pragma directive cannot be included after
// that.
int i;
COMPATIBILITY
From another C compiler to this C compiler
Modification is not required if the section name change function is not supported.
When changing the section name, modify the program according to the method above.
From this C compiler to another C compiler
Delete #pragma section ... or delimit it with #ifdef.
When changing the section name, modify the program according to the specifications of each compiler.
RESTRICTIONS
A section name that indicates a segment for the vector table (e.g., @@VECT02) must not be changed.
If two or more sections with the same name as the one specifying the AT start address exist in another file, a
link error occurs.
When changing compiler output section names @@DATS, @@BITS, and @@INIS, limit the range of the
specified address within saddr2 area.
(saddr2 area)
0xFD20 to 0xFDFF (With the small model, or when -CS0 of the medium model/large model is specified)
0xFFD20 to 0xFFDFF (When -CS15 of the medium model/large model is specified or default)
When changing compiler output section names @@DATS1, @@BITS1, and @@INIS1, limit the range of the
specified address within saddr1 area.
(saddr1 area)
0xFE00 to 0xFEFF (With the small model, or when -CS0 of the medium model/large model is specified)
0xFFE00 to 0xFFEFF (When -CS15 of the medium model/large model is specified or default)
Remark
Of the areas shown above, 0xXFE80 to 0xXFEFF (When -CS0 is specified: X = 0, when -CS15 is
specified: X = F) are areas for registers. Care must be taken when specifying these areas.
When the -CSA option is specified, the following addresses cannot be specified for the start address
specification.
0xFD00 to 0xFEFF, 0xFFD00 to 0xFFEFF
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#pragma section...
#pragma section...
CAUTION
A section is equivalent to a segment of the assembler.
The compiler does not check whether the new section name is duplicated with another symbol. Therefore,
the user must check that the section name is not duplicated by assembling the output assemble list.
If a section name (*) related to ROMization is changed by using #pragma section, the startup routine must be
changed by the user on his/her own responsibility.
(*) ROMization-related section name
@@R_INIT, @@R_INIS, @@RSINIT, @@RSINIS
@@INIT, @@INIS, @@RSINS1, @@R_INS1, @@INIS1
The startup routine to be used when a section related to ROMization is changed, and an example of changing
the end module are described below.
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#pragma section...
#pragma section...
[Examples of Changing Startup Routine in Connection with Changing Section Name Related to ROMization]
Here are examples of changing the startup routine (cstart.asm or cstartn.asm) and end module (rom.asm) in
connection with changing a section name related to ROMization.
(C source)
#pragma section @@R_INIT RTT1
#pragma section @@INIT TT1
If a section name that stores an external variable with an initial value has been changed by describing #pragma
section indicated above, the user must add to the startup routine the initial processing of the external variable to
be stored in the new section.
Therefore, add the declaration of the first label of the new section and the portion that copies the initial value to
the startup routine, and add the portion that declares the end label to the end module, as described below.
RTT1_S and RTT1_E are the names of the first and end labels of section RTT1, and TT1_S and TT1_E are the
names of the first and end labels of section TT1.
(Changing startup routine cstartx.asm)
(1) Add the declaration of the end label of the section whose name has been changed.
EXTRN
_main, _@STBEG, _hdwinit
EXTRN
RTT1_E, TT1_E
Add EXTRN declaration of RTT1_E, TT1_E
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#pragma section...
#pragma section...
(2) Add the portion that copies the initial value from the RTT1 section whose name has been changed to the TT1
section.
The initial value copying processing codes differ depending on the memory model. Initial value copying
processing can easily be added by copying the corresponding portion (initial value copying processing code)
from the startup routine referring to the memory model specified by $_IF, changing the symbols of the changed
section _@R_INIT, _?R_INIT, etc. to RTT1_S, RTT1_E, etc., and adding the changed branch symbol (to LTT1,
etc.).
:
MOV
[DE+],A
BR
$LDATS11
LDATS12 :
;
RTT1-> part added with TT1 copying processing (start)
MOVG
TDE,#TT1_S
MOVG
WHL,#RTT1_S
LTT1 :
SUBG
WHL,#RTT1_E
BE
$LTT2
ADDG
WHL,#RTT1_E
MOV
A,[HL+]
MOV
[DE+],A
BR
$LTT1
LTT2 :
;
RTT1 -> part added with TT1 copying processing (end)
$_IF(SMALL)
CALL
!_main
;main();
$ELSE
CALL
!!_main
;main();
$ENDIF
BR
$$
Add portion that copies initial value
from RTT1 section to TT1 section
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#pragma section...
#pragma section...
(3) Set the first label of the section whose name has been changed. For the attribute of segment, refer to
APPENDIX B LIST OF SEGMENT NAMES.
:
$_IF(SMALL)
@@RSINS1
CSEG
BASE
$ELSE
@@R_INS1
CSEG
$ENDIF
_@R_INS1:
@@INIS1
DSEG
SADDR
_@INIS1:
@@DATS1
DSEG
SADDR
_@DATS1:
RTT1
CSEG
RTT1_S:
Add setting of label indicating beginning of section RTT1
TT1
DSEG
TT1_S:
Add setting of label indicating beginning of section TT1
$_IF(SMALL) BASE
@@CALFS CSEG FIXEDA
@@CNSTS CSEG BASE
$ENDIF
$_IF(MEDIUM)
@@CODE CSEG
:
;
END
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#pragma section...
#pragma section...
(Changing end module rom.asm)
(1) Declare the label indicating the end of the section whose name has been changed.
:
$ELSE
NAME
@rom
$ENDIF
:
PUBLIC _?R_INIT,_?R_INIS
PUBLIC _?INIT,_?DATA,_?INIS,_?DATS
PUBLIC _?R_INS1,_?INIS1,_?DATS1
PUBLIC RTT1_E, TT1_E
Add RTT1_E and TT1_E
;
$ELSE
@@INIT DSEG
_?INIT:
@@DATA
DSEG
_?DATA:
$ENDIF
@@INIS DSEG
SADDR2
_?INIS:
@@DATS DSEG
SADDR2
_?DATS:
@@R_INS1
CSEG
_?R_INS1:
@@INIS1 DSEG
SADDR
_?INIS1:
@@DATS1 DSEG
SADDR
_?DATS1:
$ENDIF
;
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#pragma section...
#pragma section...
(2) Set the label indicating the ends.
:
RTT1 CSEG
Add setting of label indicating end of section RTT1
RTT1_E:
TT1
DSEG
Add setting of label indicating end of section TT1
TT1_E:
;
END
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(20) Binary constant
Binary Constant
Binary constant 0bxxx
FUNCTION
Describes binary constants at the location where integer constants can be described.
EFFECT
Constants can be described in bit strings without being replaced with octal or hexadecimal numbers.
Readability is also improved.
USAGE
Describe binary constants in the C source. The following shows the description method for binary constants.
0b
binary number
0B
binary number
Remark
Binary number: Either `0' or `1'
A binary constant has 0b or 0B at the start and is followed by the list of numbers 0 or 1.
The value of a binary constant is calculated with 2 as the base.
The type of a binary constant is the first one that can express the value in the following list.
.
Non-subscripted binary number:
int,
unsigned int,
long int
unsigned long int
.
Subscripted u or U:
unsigned int,
unsigned long int
.
Subscripted l or L:
long int
unsigned long int
.
Subscripted u or U and subscripted l or L:
unsigned long int
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Binary Constant
Binary constant 0bxxx
EXAMPLE
(C source)
unsigned i;
i = 0b11100101;
Output object of compiler is the same as the following case.
Unsigned i;
i = 0xE5;
COMPATIBILITY
From another C compiler to this C compiler
Modifications are not needed.
From this C compiler to another C compiler
Modification is required to meet the specifications of the compiler if the compiler supports binary constants.
Modifications into other integer formats such as octal, decimal, and hexadecimal are needed if the compiler
does not support binary constants.
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(21) Module name changing function
Module Name Changing Function
#pragma name
FUNCTION
Outputs the first eight letters of the specified module name to the symbol information table in an object module
file.
Outputs the first eight letters of the specified module name to the assemble list file as symbol information
(MOD_NAM) when G2 is specified and as the NAME quasi directive when -NG is specified.
If a module name with nine or more letters is specified, a warning message is output.
If unauthorized letters are described, an error occurs and the processing is aborted.
If more than one of this #pragma directive exists, a warning message is output, and whichever is described
later is enabled.
EFFECT
The module name of an object can be changed to any name.
USAGE
The following shows the description method.
#pragma name
module name
A module name must consist of the characters that the OS authorizes as a file name except `(` `)'. Upper case
and lowercase letters are distinguished.
EXAMPLE
#pragma name module1
:
COMPATIBILITY
From another C compiler to this C compiler
Modification is not required if the compiler does not support the module name changing function.
When changing a module name, modify the program according to the method above.
From this C compiler to another C compiler
Delete #pragma name ... or delimit it with #ifdef.
When changing a module name, modify the program according to the specification of each compiler.
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(22) Rotate function
Rotate Function
#pragma rot
FUNCTION
Outputs the code that rotates the value of an expression to the object with direct inline expansion instead of
function call and generates an object file.
If there is not a #pragma directive, the rotate function is regarded as an ordinary function.
EFFECT
The rotate function can be realized using C source or ASM description without describing the processing to
perform rotate.
USAGE
Describe in the source in the same format as a function call. There are the following four function names.
rorb, rolb, rorw, rolw
[List of functions for rotate]
(a) unsigned char rorb (x, y) ;
unsigned char x ;
unsigned char y ;
Rotates x to the right y times.
(b) unsigned char rolb (x, y) ;
unsigned char x ;
unsigned char y ;
Rotates x to the left y times.
(c) unsigned int rorw (x, y) ;
unsigned int x ;
unsigned char y ;
Rotates x to the right y times.
(d) unsigned int rolw (x, y)
unsigned int x ;
unsigned char y ;
Rotates x to the left y times.
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Rotate Function
#pragma rot
Declare the use of the function for rotate by the #pragma rot directive of the module.
However, the following items can be described before #pragma rot.
Comments
Other #pragma directives
Preprocessing directives that neither define nor reference variables or functions.
Keywords following #pragma can be described in either uppercase or lowercase letters.
EXAMPLE
(C source)
#pragma rot
unsigned char a = 0x11;
unsigned char b = 2;
unsigned char c;
void main ( ) {
c = rorb(a, b);
}
(Output assembler source) with large model
_main:
mov
c,!!_b
mov
a,!!_a
ror
a,1
dbnz
c,$$-2
mov
!!_c,a
ret
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Rotate Function
#pragma rot
RESTRICTIONS
The function names for rotate cannot be used as the function names.
The function names for rotate must be described in lowercase letters. If the functions for rotate are described
in uppercase letters, they are handled as ordinary functions.
COMPATIBILITY
From another C compiler to this C compiler
Modification is not required if the compiler does not use the functions for rotate.
When changing to functions for rotate, modify the program according to the method above.
From this C compiler to another C compiler
Delete the #pragma rot statement or delimit it with #ifdef.
When using as a function for rotate, modification is required according to the specification of each compiler
(#asm, #endasm or asm() ; , etc.).
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(23) Multiplication function
Multiplication Function
#pragma mul
FUNCTION
Outputs the code that multiplies the value of an expression to an object with direct inline expansion instead of
function call and generates an object file.
If there is not a #pragma directive, the multiplication function is regarded as an ordinary function.
EFFECT
Codes utilizing the data size of the multiplication instruction I/O are generated. Therefore, codes with faster
execution speed and smaller size than the description of ordinary multiplication expressions can be
generated.
USAGE
Describe in the same format as that of a function call in the source. There are the following three functions for
multiplication.
mulu, muluw, mulw
[List of multiplication functions]
(a) unsigned int mulu (x, y);
unsigned char x;
unsigned char y;
Performs unsigned multiplication of x and y.
(b) unsigned long muluw (x, y);
unsigned int x;
unsigned int y;
Performs unsigned multiplication of x and y.
(c) long mulw (x, y);
int x;
int y;
Performs signed multiplication of x and y.
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Multiplication Function
#pragma mul
Declare the use of functions for multiplication with the #pragma mul directive of the module.
However, the following items can be described before #pragma mul.
Comments
Other #pragma directives
Preprocessing directives that neither define nor reference variables or functions.
Keywords following #pragma can be described in either uppercase or lowercase letters.
RESTRICTIONS
Multiplication functions are handled as ordinary function if the target device does not have multiplication
instructions.
The function names for multiplication cannot be used as the function names (when #pragma mul is declared).
The functions for multiplication must be described in lowercase letters. If they are described in uppercase
letters, they are handled as ordinary function.
EXAMPLE
(C source)
#pragma mul
unsigned char a = 0x11;
unsigned char b = 2;
unsigned int I;
void main()
{
i = mulu(a, b);
}
(Output object of compiler)
_main:
mov
a,!!_b
mov
b,!!_a
mulu
b
movw
!!_i,ax
ret
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Multiplication Function
#pragma mul
COMPATIBILITY
From another C compiler to this C compiler
Modification is not required if the compiler does not use the functions for multiplication.
When changing to functions for multiplication, modify the program according to the method above.
From this C compiler to another C compiler
Delete the #pragma mul statement or delimit it with #ifdef. Function names for multiplication can be used
as the function names.
When using as functions for multiplication, modification is required according to the specification of each
compiler (#asm, #endasm or asm() ;, etc.).
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(24) Division function
Division Function
#pragma div
FUNCTION
Outputs the code that divides the value of an expression to an object with direct inline expansion instead of
function call and generates an object code file.
If there is not a #pragma directive, the function for division is regarded as an ordinary function.
EFFECT
Codes utilizing the data size of the division instruction I/O are generated. Therefore, codes with faster
execution speed and smaller size than the description of ordinary division expressions can be generated.
USAGE
Describe in the same format as that of a function call in the source. There are the following two functions for
division.
divuw, moduw
[List of division functions]
(a) unsigned int divuw(x, y);
unsigned int x;
unsigned char y;
Performs unsigned division of x and y and returns the quotient.
(b) unsigned char moduw(x, y);
unsigned int x;
unsigned char y;
Performs unsigned division of x and y and returns the remainder.
Declare the use of the functions for division with the #pragma div directive of the module.
However, the following items can be described before #pragma div.
Comments
Other #pragma directives
Preprocessing directives that neither define nor reference variables or functions.
Keywords following #pragma can be described in either uppercase or lowercase letters.
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Division Function
#pragma div
RESTRICTIONS
The division function is handled as an ordinary function if the target device does not have division instructions.
The function names for division cannot be used as the function names.
The function names for division must be described in lowercase letters. If they are described in uppercase
letters, they are handled as ordinary functions.
EXAMPLE
(C source)
#pragma div
unsigned int a = 0x1234;
unsigned char b = 0x12;
unsigned char c;
unsigned int I;
void main () {
i = divuw(a, b);
c = moduw(a, b);
}
(Output object of compiler) With large model
_main:
mov
b,!!_b
movw
ax,!!_a
divuw
b
movw
!!_i,ax
mov
b,!!_b
movw
ax,!!_a
divuw
b
mov
!!_c,b
ret
COMPATIBILITY
From another C compiler to this C compiler
Modification is not required if the compiler does not use the functions for division.
When changing to functions for division, modify the program according to the method above.
From this C compiler to another C compiler
Delete the #pragma div statement or delimit it with #ifdef. The function names for division can be used
as the function names.
When using as a function for division, modification is required according to the specification of each
compiler (#asm, #endasm or asm() ; , etc.).
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(25) Data insertion function
Data Insertion Function
#pragma opc
FUNCTION
Inserts constant data into the current address.
When there is not a #pragma directive, the function for data insertion is regarded as an ordinary function.
EFFECT
Specific data and instructions can be embedded in the code area without using the ASM statement.
When ASM is used, an object cannot be obtained without going through the assembler. On the other hand, if
the data insertion function is used, an object can be obtained without going through the assembler.
USAGE
Describe using uppercase letters in the source in the same format as that of a function call.
The function name for data insertion is _ _OPC.
[List of data insertion functions]
(a) void _ _OPC (unsigned char x,
...);
Insert the value of the constant described in the argument to the current address.
Arguments can describe only constants.
Declare the use of functions for data insertion with the #pragma opc directive.
However, the following items can be described before #pragma opc.
Comments
Other #pragma directives
Preprocessing directives that neither define nor reference variables or functions.
Keywords following #pragma can be described in either uppercase or lowercase letters.
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Data Insertion Function
#pragma opc
RESTRICTIONS
The function names for data insertion cannot be used as the function names (when #opc is specified).
_ _OPC must be described in uppercase letters. If it is described in lowercase letters, it is handled as an
ordinary function.
EXAMPLE
(C source)
#pragma opc
void main ( ) {
_ _OPC(0xBF);
_ _OPC(0xA1, 0x12);
_ _OPC(0x10, 0x34, 0x12);
}
(Output object of compiler)
_main:
; line
4 : _ _OPC (0xBF);
DB 0BFH
; line
5 : _ _OPC (0xA1, 0x12);
DB 0A1H
DB 012H
; line
6 : _ _OPC (0x10, 0x34, 0x12);
DB 010H
DB 034H
DB 012H
ret
COMPATIBILITY
From another C compiler to this C compiler
Modification is not required if the compiler does not use the functions for data insertion.
When changing to functions for data insertion, modify the program according to the method above.
From this C compiler to another C compiler
Delete the #pragma opc statement or delimit it with #ifdef.
Function names for data insertion can be used as function names. When using as a function for data
insertion, modification is required according to the specification of each compiler (#asm, #endasm or
asm() ; , etc.).
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(26) Interrupt handler for real-time OS (RTOS)
Interrupt Handler for RTOS
#pragma rtos_interrupt ...
FUNCTION
Interprets the function name specified by the #pragma rtos_interrupt directive as the interrupt handler for the
78K/IV Series RTOS (real-time OS) RX78K/IV.
Registers the address of the described function name to the interrupt vector table for the specified interrupt
request name.
When a stack change is specified, the stack pointer is changed to the location where the offset is added to the
array name symbol. The area of the array name is not secured by the #pragma directive. It needs to be
defined separately as a global unsigned char type array.
The two system call calling functions ret_int/ret_wup can be called in the interrupt handler for RTOS (for the
details of the system call calling function, refer to the List of RTOS System Call Calling Functions described
later).
If the prototype declaration or the entity definition of ret_int/ret_wup and ret_int/ret_wup are called outside
the interrupt handler for RTOS, an error occurs.
The two RTOS system call calling functions ret_int/ret_wup are called by an unconditional branch instruction.
If there is neither ret_int nor ret_wup in the interrupt handler for RTOS, an error occurs.
If the interrupt request name and thereafter is omitted, only the two functions ret_int/ret_wup are enabled.
The interrupt handler for RTOS generates codes in the following order.
(1) Saves all the registers
(2) Changes the stack pointer (only when stack change is specified)
(3) Secures the local variable area (only when there is a local variable)
(4) The function body
(5) Releases the local variable area (only when there is a local variable)
(6) Sets back the stack pointer (only when stack change is specified)
(7) Restores all the registers
(8) reti
For ret_int/ret_wup described in the middle of the function, the codes in (5) and (6) are generated immediately
before the unconditional branch instruction each time.
If a function ends with ret_int/ret_wup, the codes in (7) and (8) are not generated.
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Interrupt Handler for RTOS
#pragma rtos_interrupt ...
EFFECT
The interrupt handler for RTOS can be described at the C source level.
Because the interrupt request name is identified, the address of the vector table does not need to be
identified.
USAGE
The interrupt request name, function name, and stack change is specified by the #pragma directive.
This #pragma directive is described at the start of the C source.
When #pragma PC (type) is described, the main #pragma directive is described after #pragma PC.
The following items can be described before #pragma directive.
Comments
Preprocessing directives that neither define nor reference variables or functions.
#pragma
rtos_interrupt [ Interrupt request name function name [stack change specification]]
Remark Stack change specification: SP = array name [+ offset location]
Of the keywords to be described following #pragma, the interrupt request name must be described in
uppercase letters. The other keywords can be described either in uppercase or lowercase letters.
[List of RTOS system call calling functions]
(1) void ret_int ( );
Calls RTOS system call ret_int.
(2) void ret_wup (x);
char *x;
Calls RTOS system call ret_wup with x as an argument.
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Interrupt Handler for RTOS
#pragma rtos_interrupt ...
RESTRICTIONS
Interrupt request names are described in uppercase letters.
Software interrupts and non-maskable interrupts cannot be specified for the interrupt request names. If
specified so, an error occurs.
A duplication check on interrupt request names will be made within only one module.
If an interrupt (the same or another interrupt) is generated in duplicate during vector interrupt processing due
to the contents of the priority specification flag register, interrupt mask flag register, etc., if the stack change is
specified, the contents of the stack are updated, which may cause problems. However, this cannot checked
by the compiler, so care must be taken.
callt/callf/noauto/norec/_ _callt/_ _callf/_ _leaf/_ _interrupt/_ _interrupt_brk/_ _pascal/_ _flash cannot be
specified for the interrupt handler for RTOS.
The RTOS system call calling function names ret_int/ret_wup cannot be used for the function names.
If the functions that specified the stack change via the #pragma rtos_interrupt specification are not defined
in the same module, a warning is output and the stack change specification is ignored.
The interrupt handler for RTOS is not supported when the static model is specified.
EXAMPLE
(a) When stack change is not specified
(C source)
#pragma rtos_interrupt INTP0 intp
int I;
void intp ( ) {
int a;
a = 1;
if (i == 1) {
ret_int();
}
}
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Interrupt Handler for RTOS
#pragma rtos_interrupt ...
(Output object of compiler)
When -ML, -QV is specified (default)
@@BASE CSEG
BASE
_intp:
push
whl
;
Saves register
push
tde
push
uup
push
vvp
push
ax,bc,rp2,rp3
movw
rp3,#01H
;
Allocates RP3 to variable a
Note
movw
ax,!!_i
cmpw
ax,rp3
bne
$L0003
br
!!_ret_int
L0003;
pop
ax,bc,rp2,rp3
;
Restores register
pop
vvp
pop
uup
pop
tde
pop
whl
reti
@@VECT06
CSEG
AT
0006H
_@vect06:
DW
_intp
Note
When the -QV option is not specified, the securing/releasing codes of the local variables are output after
saving the register/before restoring the register, respectively.
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Interrupt Handler for RTOS
#pragma rtos_interrupt ...
(b) When the stack change is specified
(C source)
#pragma rtos_interrupt INTP0 intp sp=buff+10
int I;
unsigned char buff[10];
extern unsigned short TaskID1;
void intp () {
int a;
a = 1;
if (i == 1) {
ret_wup (&TaskID1);
}
}
(Output object of compiler)
When -ML, -QV is specified (default)
@@BASE CSEG
BASE
_intp :
push
whl
;
Saves register
push
tde
push
uup
push
vvp
push
ax,bc,rp2,rp3
movg
whl,sp
movg
sp,#_buff+10
;
Changes stack pointer
push
whl
movw
rp3,#01H ;
Allocates RP3 to variable a
Note
movw
ax,!!_;
cmpw
ax,rp3
bne
$L0003
movg
uup,#_TaskID1
Note When the -QV option is not specified, the securing/releasing codes of the local variable area are output.
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Interrupt Handler for RTOS
#pragma rtos_interrupt ...
(Output object of compiler)
When -ML, -QV is specified (default)
pop
whl
;
Sets back stack pointer
movg
sp,whl
br
!!_ret_wup
L0003 :
pop
whl
;
Sets back stack pointer
movg
sp,whl
pop
ax,bc,rp2,rp3
;
Restores register
pop
vvp
pop
uup
pop
tde
pop
whl
reti
@@VECT06
CSEG AT 0006H
_@vect06:
DW
_intp
COMPATIBILITY
From another C compiler to this C compiler
Modification is not required if the compiler does not support the interrupt handler for RTOS.
When changing to the interrupt handler for RTOS, modify the program according to the method above.
From this C compiler to another C compiler
Handled as an ordinary function if the #pragma rtos_interrupt specification is deleted.
When using as an interrupt handler for RTOS, modification is required according to the specification of each
compiler.
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(27) Interrupt handler qualifier for real-time OS (RTOS)
Interrupt Handler Qualifier for RTOS
__rtos_interrupt
FUNCTION
The function declared with the _ _rtos_interrupt qualifier is interpreted as an interrupt handler for RTOS.
The two RTOS system call calling functions ret_int/ret_wup can be called in the function declared with the
keywords _ _rtos_interrupt (for details of the RTOS system call calling functions, refer to List of RTOS
System Call Calling Functions described later).
If the prototype declaration or the entity definition of ret_int/ret_wup and ret_int/ret_wup are called outside
the interrupt handler for RTOS, an error occurs.
The functions to call the two RTOS system call calling functions ret_int/ret_wup are called by an
unconditional branch instruction.
If there is neither ret_int nor ret_wup in the interrupt handler for RTOS, an error occurs.
EFFECT
The setting of the vector table and the definition of the interrupt handler function for RTOS can be described in
separate files.
USAGE
_ _rtos_interrupt is added to the qualifier of the interrupt handler for RTOS.
_ _rtos_interrupt void func ( ) {
Processing }
[List of the system call calling functions for RTOS]
(a) void ret_int ( ) ;
Calls system call ret_int for RTOS.
(b) void ret_wup (x) ;
char *x ;
Calls system call ret_wup for RTOS with x as an argument.
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Interrupt Handler Qualifier for RTOS
__rtos_interrupt
RESTRICTIONS
callt/callf/noauto/norec/_ _callt/_ _callf/_ _leaf/ _ _interrupt/_ _interrupt_brk/ _ _ pascal/_ _ flash cannot be
specified for the interrupt handler for RTOS.
The RTOS system call calling function names ret_int/ret_wup cannot be used for the function names.
CAUTIONS
Vector addresses cannot be set only by declaring this qualifier.
The setting of the vector address must be performed separately by the #pragma directive, assembler
description, etc.
When the interrupt handler for RTOS is defined in the same file as the one in which the #pragma
rtos_interrupt is specified, the function name specified with #pragma rtos_interrupt is judged as an
interrupt handler for RTOS even if this qualifier is not described.
COMPATIBILITY
From another C compiler to this C compiler
Modification is not required if the compiler does not support interrupt handler for RTOS.
When changing to interrupt handler for RTOS, modify the program according to the method above.
From this C compiler to another C compiler
Changes can be made by #define (for details, refer to 11.6 Modifications of C Source). By these
changes, interrupt handler qualifiers for RTOS are handled as ordinary variables.
When using as an interrupt handler for RTOS, modification is required according to the specification of
each compiler.
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(28) Task function for real-time OS (RTOS)
Task Function for RTOS
#pragma rtos_task
FUNCTION
The function names specified with #pragma rtos_task are interpreted as the tasks for RTOS.
If the function name is specified and the entity definition is not in the same file, an error occurs.
The preprocessing of the task function for RTOS does not save the registers for frame pointer/register
variables. The postprocessing is not output.
The following RTOS system call calling functions can be used.
[RTOS system call calling functions]
(a) void ext_tsk (void);
Calls RTOS system call ext_tsk.
However, when ext_tsk is called in the ext_tsk prototype declaration or entity definition, interrupt function, or
interrupt handler for RTOS, an error occurs.
The RTOS system call calling function of ext_tsk is called by an unconditional branch instruction. If ext_tsk
is issued after the function, the postprocessing is not output.
When there is no ext_tsk in the task function for RTOS and the -W2 option is specified, a warning message is
output.
EFFECT
The task function for RTOS can be described at the C source level.
The saving and postprocessing of the register frame pointer/register variable are not output, so the code
efficiency is improved.
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Task Function for RTOS
#pragma rtos_task
USAGE
Specifies the function name for the following #pragma directives.
The #pragma directives are described at the start of the C source.
However, the following items can be described before the #pragma directive.
Comments
Preprocessing directives that neither define nor reference variables or functions.
Keywords following #pragma can be described either in uppercase or lowercase letters.
#pragma
rtos_task [task-function-name]
RESTRICTIONS
callt/callf/noauto/norec/_ _callt/_ _callf/_ _leaf/_ _interrupt/_ _interrupt brk/_ _rtos_interrupt/ _ _ pascal/_ _
flash cannot be specified for the task function for RTOS.
The task function for RTOS cannot be called in the same manner as ordinary functions.
The RTOS system call calling function name ext_tsk cannot be used for a function name.
The task function for RTOS is not supported when the medium model is specified.
EXAMPLE
(C source)
#pragma rtos_task func
void main ( ) {
int a;
a = 1;
ext_tsk ();
}
void func ( ) {
register int r;
int x;
x = 1;
r = 2;
ext_tsk ();
}
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Task Function for RTOS
#pragma rtos_task
(Output object of compiler)
When -ML, -QV is specified (default)
@@CODE
CSEG
_main :
push
rp3
movw
rp3,#01H
;
1
br
!!_ext_tsk
;
Epilogue is not output.
_func :
;
Frame pointer is not saved.
movw
up,#01H
;
1
movw
rp3,#02H
;
2
br
!!_ext_tsk
;
Epilogue is not output.
END
COMPATIBILITY
From another C compiler to this C compiler
Modification is not required if the compiler does not support the task function for RTOS.
When changing to the task function for RTOS, modify the program according to the method above.
From this C compiler to another C compiler
If the #pragma rtos_task specification is deleted, the RTOS task function is used as an ordinary function.
To use as RTOS task function, modification is required according to the specification of each compiler.
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(29) Changing function call interface
Changing Function Call Interface
-ZO
FUNCTION
Arguments are passed in accordance with the former function interface specifications (in CC78K4 V1.00
compatible products, only the stack is used). For details of the function interface, refer to 11.7 Function Call
Interface.
USAGE
The -ZO option is specified during compilation.
RESTRICTION
Modules to which the -ZO option is specified and modules to which the -ZO option is not specified cannot be
linked to one another.
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(30) Changing the method of calculating the offset of arrays and pointers
Changing the Method of Calculating the Offset of Arrays and Pointers
-QH
FUNCTIONS
When calculating the offset of arrays and pointers (distance from the start of the array or pointer), if the index
is an int/short type variable, it is regarded as unsigned int/unsigned short, and if the index is a char type
variable, it is regarded as unsigned char.
Calculates the offset as a positive 64 KB or less.
However, the ordinary offset calculation is performed if the index is a long type variable or a constant.
EFFECT
The code efficiency is improved by performing unsigned offset calculation.
USAGE
The -QH option is specified during compilation.
RESTRICTIONS
Access to an object by array elements and pointers can be performed only when the offset is 64 KB or less.
The offset for the minus direction cannot be calculated.
COMPATIBILITY
From another C compiler to this C compiler
When the index to arrays and pointers is a int/short type variable or char type variable and there is
access to a minus-direction object or access to an object of more than 64 KB, the index is changed to a
long type variable. Otherwise, the -QH option should not be specified.
From this C compiler to another C compiler
Modification is not required.
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Changing the Method of Calculating the Offset of Arrays and Pointers
-QH
EXAMPLE
(C source)
int tabi [100];
char tabc [100];
int *iptr;
void main (void) {
long I = 50;
int i = 30;
char c = 2;
tabi [i] = 1;
/* unsigned offset calculation, 64 KB or less */
tabc [c] = 2;
/* unsigned offset calculation, 64 KB or less */
tabi [l] = 3;
/* signed offset calculation */
*(iptr + i) = 4;
/* unsigned offset calculation, 64 KB or less */
*(iptr + (-i)) = 5;
/* offset calculation, positive 64 KB or less */
*(iptr - i) = 6;
/* signed offset calculation */
*(iptr -10) = 7;
/* signed offset calculation */
*(iptr + (-10)) = 8;
/* signed offset calculation */
}
(Output object of compiler)
When -ML, -QH is specified (1/3)
@@CODE CSEG
_main:
push
uup
push
rp3
push
vvp
; line 6:
long 1 = 50;
movw
rp3,#032H
;50
subw
vp,vp
; line 7:
int i = 30;
movw
up,#01EH
;30
; line 8:
char c= 2;
mov
c,#02H
;2
; line 9:
; line 10 :
tabi [i] = 1;
/* unsigned offset calculation, 64 KB or less */
movw
hl,up
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Changing the Method of Calculating the Offset of Arrays and Pointers
-QH
(Output object of compiler)
When -ML, -QH is specified (2/3)
Addw hl,hl ;
Offset calculation only for the lower 2 bytes
Movw ax,#01H ;
1
Movw _tabi[hl],ax
; line 11 : tabc [c] = 2;
/* unsigned offset calculation, 64 KB or less */
mov a,c
xch a,b
mov a,c
mov _tabc[b],a ;
Offset calculation only for the least significant byte
; line 12 :
tabi [l] = 3;
/* signed offset calculation */
movw hl,rp3
mov a,r8
mov w,a
addg whl,whl
;
Offset is 3 bytes, sign is considered
addg whl,#_tabi
movw ax,#03H
;
3
movw [h],ax
; line 13 : *(iptr + i) = 4;
/* unsigned offset calculation, 64 KB or less */
movw hl,up
movg tde,!!_iptr
addw hl,hl ;
Offset calculation only for the lower 2 bytes
addg tde,whl
incw ax
movw [de],ax
; line 14 : *(iptr + (-i)) = 5;
/* offset calculation, positive 64 KB or less */
subw ax,ax
subw ax,up
movg whl,!!_iptr
movw de,ax
mov t,#00H
;
0
addw de,de
;
Offset calculation only for the lower 2 bytes
addg whl,tde
movw ax,#05H
;
5
movw [hl],ax
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Changing the Method of Calculating the Offset of Arrays and Pointers
-QH
(Output object of compiler)
When -ML, -QH is specified (3/3)
; line 15 :
*(iptr - i) = 6 ;
/* signed offset calculation */
movw
hl,up
mov
a,h
cvtbw
mov
w,a
movg
tde,!!_iptr
addg
whl,whl
;
Offset is 3 bytes
subg
tde,whl
movw
ax,#06H
;
6
movw
[de],ax
; line 16 :
*(iptr - 10) = 7 ;
/* signed offset calculation */
movg
whl,!!_iptr
incw
ax
addg
whl,#0FFFFECH ; -20
; Offset is a signed constant (
-20)
movw
[hl],ax
; line 17 ;
*(iptr + (-10)) = 8 ;
/* signed offset calculation */
movg
whl,!!iptr
incw
ax
addg
whl,#0FFFFECH ; -20
; Offset is a signed constant (
-20)
movw
[hl],ax
; line 18 ; }
pop
vvp
pop
rp3
pop
uup
ret
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Changing the Method of Calculating the Offset of Arrays and Pointers
-QH
(Output object of compiler)
When -ML, -QH is not specified (1/3)
@@CODE CSEG
_main :
push
uup
push
rp3
push
vvp
; line 6:
long I = 50;
movw
rp3,#032H
;
50
subw
vp,vp
; line 7:
int i = 30;
movw
up,#01EH
;
30
; line 8:
char c= 2;
mov
c,#02H
;
2
; line 9:
; line 10 :
tabi [i] = 1;
/* unsigned offset calculation, 64 KB or less */
movw
hl,up
mov
a,h
cvtbw
mov
w,a
addg
whl,whl
addg
whl,#_tabi
movw
ax,#01H
;
1
movw
[hl],ax
; line 11 :
tabc [c] = 2;
/* unsigned offset calculation, 64 KB or less */
mov
a, c
cvtbw
movw
hl,ax
mov
w,a
addg
whl,#_tabc
mov
a, c
mov
[hl],a
; line 12 :
tabi [l] = 3;
/* signed offset calculation */
movw
hl,rp3
mov
a,r8
mov
w,a
addg
whl,whl
addg
whl,#_tabi
movw
ax,#03H
;
3
movw
[hl],ax
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Changing the Method of Calculating the Offset of Arrays and Pointers
-QH
(Output object of compiler)
When -ML, -QH is not specified (2/3)
; line
13 :
*(iptr + i) = 4;
/* unsigned offset calculation, 64 KB or less */
movw
hl,up
movg
tde,!!_iptr
mov
a,h
cvtbw
mov
w,a
addg
whl,whl
addg
tde,whl
movw
ax,#04H
;
4
movw
[de],ax
; line
14 :
*(iptr + (-i)) = 5;
/* offset calculation positive 64 KB or less */
subw
ax,ax
subw
ax,up
movg
whl,!!_iptr
movw
de,ax
cvtbw
mov
t,a
addg
tde,tde
addg
whl,tde
movw
ax,#05H
;
5
movw
[hl],ax
; line
15 :
*(iptr - i) = 6;
/* signed offset calculation */
movw
hl,up
mov
a,h
cvtbw
mov
w,a
movg
tde,!!_iptr
addg
whl,whl
subg
tde,whl
movw
ax,#06H
;
6
movw
[de],ax
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Changing the Method of Calculating the Offset of Arrays and Pointers
-QH
(Output object of compiler)
When -ML, -QH is not specified (3/3)
; line 16 :
*(iptr - 10) = 7;
/* signed offset calculation */
movg
whl,!!_iptr
incw
ax
addg
whl,#0FFFFECH
;
-20
movw
[hl],ax
; line 17 :
*(iptr + (-10)) = 8;
/* signed offset calculation */
movg
whl,!!_iptr
incw
ax
addg
whl,#0FFFFECH
;
-20
movw
[hl],ax
; line 18 : }
pop
vvp
pop
rp3
pop
uup
ret
COMPATIBILITY
From another C compiler to this C compiler
When the index to arrays and pointers is a int/short type variable or char type variable and there is
access to a minus-direction object or access to an object of more than 64 KB, the index is changed to a
long type variable. Otherwise, the -QH option should not be specified.
From this C compiler to another C compiler
Modification is not required.
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(31) Pascal function
Pascal Function
_ _pascal
FUNCTION
Generates the code that corrects the stack used for placing of arguments when a function is called on the
called function side, not on the side calling the function.
EFFECT
Object code can be shortened if a lot of function calls appear.
USAGE
When a function is declared, a _ _pascal attribute is added to the beginning.
RESTRICTIONS
The pascal function does not support variable length arguments. If a variable length argument is defined, a
warning is output and the _ _pascal keyword is disregarded.
In a pascal function, the keywords norec/_ _interrupt/_ _interrupt_brk/_ _rtos_interrupt/_ _flash cannot be
specified. If they are specified, in the case of the norec keyword, the _ _pascal key word is disregarded and
in the case of the _ _interrupt/_ _interrupt_brk/_ _rtos_interrupt/_ _flash keywords, an error is output.
The old specification function interface specification option (-ZO) does not support the pascal function. When
pascal functions are used, if -ZO is specified, a warning message is output at the first place where a
_ _pascal key word appears and the _ _pascal keywords in the input file are disregarded.
If a prototype declaration is incomplete, it won't operate normally, so a warning message is output when a
pascal function's physical definition or prototype declaration is missing.
EXPLANATION
The -ZR option enables the change of all functions to the pascal function. However, if the pascal function is
used to change functions that have few function calls, object code may increase.
EXAMPLE
(C source)
_ _pascal int func(int a, int b, int c);
void main()
{
int ret_val;
ret_val = func(5, 10, 15);
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Pascal Function
_ _pascal
(C source) (continued)
}
_ _pascal int func(int a, int b, int c)
{
return (a + b + c);
}
(Output object of compiler)
With large model
_main:
push
rp3
movw
ax,#0FH ;
push
ax
;
mov
x,#0AH
;
push
ax
;
mov
x,#05H
;
With the argument, a 4-byte stack is consumed.
call
$!_func
;
Here stack correction is not performed.
movw
rp3,bc
pop
rp3
ret
_func:
push
rp3
movw
rp3,ax
movw
ax,[sp+5]
addw
ax,rp3
movw
bc,ax
movw
ax,[sp+7]
addw
bc,ax
pop
rp3
pop
whl
;
Obtain the return address.
pop
ax,rp2
;
The 4-byte stack consumed on the calling side is corrected.
br
whl
;
Branch to the return address.
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Pascal Function
_ _pascal
COMPATIBILITY
From another C compiler to this C compiler
Modification is not required if the reserved word _ _ pascal is not used.
When changing to the pascal function, modify the program according to the method above.
From this C compiler to another C compiler
Compatibility is maintained by using #define.
By this conversion, the pascal function is regarded as an ordinary function.
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(32) Automatic pascal functionization of the function call interface
Automatic Pascal Functionization of the Function Call Interface
-ZR
FUNCTION
With the exception of norec/_ _interrupt/_ _interrupt_brk/_ _rtos_interrupt/_ _flash and functions with
variable length arguments, _ _pascal attributes are added to all functions.
USAGE
The -ZR option is specified during compilation.
RESTRICTIONS
The old specification function interface specification option (-ZO) cannot be used at the same time. If this is
used, a warning message is output and the -ZR option is ignored.
Modules in which the -ZR option is specified and modules in which the -ZR option is not specified cannot be
linked. If a link is executed, it results in a link error.
Remark For details of the pascal function call interface, refer to 11.7.5 Pascal function call interface.
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(33) Flash area allocation method
Flash Area Allocation Method
-ZF
Caution Do not use this flash function for devices that have no flash area self-rewrite function.
Operation is not guaranteed if it is used.
This function enables the flash memory rewrite function of devices.
FUNCTIONS
Generates an object file located in the flash area.
External variables in the flash area cannot be referenced from the boot area.
External variables in the boot area can be referenced from the flash area.
The same external variables and the same global functions cannot be defined in a boot area program and a
flash area program.
EFFECT
Enables locating a program in the flash area.
Enables using function linking with a boot area object created without specifying the -ZF option.
USAGE
The -ZF option is specified during compilation.
RESTRICTION
Use startup routines or library for the flash area.
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(34) Flash area branch table
Flash Area Branch Table
#pragma ext_table
Caution Do not use this flash function for devices that have no flash area self-rewrite function.
Operation is not guaranteed if it is used.
This function enables the flash memory rewrite function of devices.
FUNCTIONS
Determines the first address of the branch table for the startup routine, the interrupt function, or the function
call from the boot area to the flash area.
The branch instruction, which is one of the branch table elements, occupies 4 bytes of area. 32 from the first
address of the branch table are reserved as dedicated interrupt functions. Ordinary functions are located after
the "first address of branch table +4 * 32."
The branch table occupies 4* (32 + ext_func ID max. value + 1) bytes of area. For the ext_func ID value,
refer to 11.5 (35) Function call function from the boot area to the flash area.
EFFECT
A startup routine and interrupt function can be located in the flash area.
A function call can be performed from the boot area to the flash area.
USAGE
The following #pragma directive specifies the first address of the flash area branch table.
#pragma
ext_table branch-table-first-address
Describe the #pragma directive at the beginning of the C source.
The following items can be described before the #pragma directive.
Comments
#pragma directive other than #pragma ext_func, #pragma vect with ZF specification, #pragma
interrupt, or #pragma rtos_interrupt.
Directives not to generate the definition/reference of variables or functions among the preprocessing
directives.
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Flash Area Branch Table
#pragma ext_table
RESTRICTIONS
The branch table is located at the first address of the flash area.
If #pragma ext_table does not exist before #pragma ext_func, #pragma vect with ZF specification,
#pragma interrupt, or #pragma rtos_interrupt, an error occurs.
The first address of the branch table is assumed to be 0x80 to 0xff80. However, match the first address value
with the flash start address which is specified by the -ZB linker option. If the address does not match, it results
in a link error.
It is necessary to reconfigure the library for interrupt vectors (_@vect100 to _@vect3e) in accordance with
the specified first address of the branch table. The default is 4000H in the interrupt vector library. To specify a
value other than 0x4000, reconfigure the library as shown below.
1. Change the place of H in ITBLTOP EQU 4000H of vect.inc in the \NECTools32\SRC\CC78K4\SRC directory
to the specified address.
2. Run \NECTools32\SRC\CC78K4\BAT/repvect.bat in DOS prompt, and update library using the assembler, etc.
Copy the updated library \NECTools32\SRC\CC78K4\LIB to \NECTools32\LIB78K4 to be used for linking.
Caution
The above directory may differ depending on the installation method.
COMPATIBILITY
From another C compiler to this C compiler
Modification is not required if #pragma ext_table is not used.
When specifying the first address of the flash area branch table, change the address according to the
method above.
From this C compiler to another C compiler
Delete the #pragma ext_table instruction or delimit it with #ifdef.
When specifying the first address of the flash area branch table, the following modification is required.
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Flash Area Branch Table
#pragma ext_table
EXAMPLE
To generate the branch table after the address 4000H and allocate the interrupt function.
(C source)
#pragma ext_table 0x4000
#pragma interrupt INTP0 intp
void intp()
{
}
(Output object of compiler)
(a) To allocate the interrupt function to the boot area (no -ZF specification).
PUBLIC
_@vect06
PUBLIC
_intp
@@BASE
CSEG
BASE
_intp:
reti
@@VECT06
CSEG
AT 0006H
_@vect06:
DW _intp
Set the first address of the interrupt function in the interrupt vector table.
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Flash Area Branch Table
#pragma ext_table
(b) To allocate the interrupt vector table to the flash area (-ZF specified).
PUBLIC
_intp
@ECODE
CSEG
_intp:
reti
@EVECT06
CSEG
AT
0400CH
br
!!_intp
(Library for interrupt vector 06)
PUBLIC
_@vect06
@@VECT06 CSEG
AT 0006H
_vect06:
DW
400CH
Set the first address of the interrupt function in the branch table.
The first address of the branch table is 4000H and the interrupt vector address (2 bytes) is
0006H, so the address of the branch table becomes 4000H + 4*(0006H/2).
Setting the 400CH address in the interrupt vector table is performed by the interrupt vector
library.
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(35) Function call function from the boot area to the flash area
Function Call Function from the Boot Area to the Flash Area #pragma ext_func
Caution Do not use this flash function for devices that have no flash area self-rewrite function.
Operation is not guaranteed if it is used.
This function enables the flash memory rewrite function of devices.
FUNCTIONS
Function calls from the boot area to the flash area are executed via the flash area branch table.
Functions in the boot area can be called directly from the flash area.
EFFECT
It becomes possible to call a function in the flash area from the boot area.
USAGE
The following #pragma directive specifies the function name and ID value in the flash area called from the
boot area.
#pragma
ext_func function-name ID value
This #pragma directive is described at the beginning of the C source. The following items can be described before
this #pragma directive.
Comments
Directives that do not generate the definition/reference of variables or functions among the preprocessing
directives.
RESTRICTIONS
The ID value is set to 0 to 255 (0xFF).
If #pragma ext_table does not exist before #pragma ext_func, it results in an error.
If the same function has a different ID value or a different function has the same ID value, an error occurs. (a)
and (b) below are errors.
(a) #pragma ext_func f1 3
#pragma ext_func f1 4
(b) #pragma ext_func f1 3
#pragma ext_func f2 3
If a function is called from the boot area to the flash area and there is no corresponding function definition in
the flash area, the linker cannot conduct a check. This is the user's responsibility.
The callt and callf functions can only be located in the boot area. If the callt and callf functions are defined in
the flash area (when the -ZF option is specified), it results in an error.
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Function Call Function from the Boot Area to the Flash Area #pragma ext_func
COMPATIBLITY
From another C compiler to this C compiler
Modification is not required if the #pragma ext_func is not used.
When performing the function call from the boot area to the flash area, modify the program according to
the method above.
From this C compiler to another C compiler
Delete the #pragma ext_func instruction or delimit it with #ifdef.
When performing the function call from the boot area to the flash area, the following modification is
required.
EXAMPLE
In the case that the branch table is generated after address 4000H and functions f1 and f2 in the flash area are called
from the boot area.
(C source)
(1) Boot area side
#pragma ext_table 0x4000
#pragma ext_func f1 3
#pragma ext_func f2 4
extern void f1(void);
extern void f2(void);
void func()
{
f1();
f2();
}
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Function Call Function from the Boot Area to the Flash Area #pragma ext_func
(2) Flash area side
#pragma ext_table 0x4000
#pragma ext_func f1 3
#pragma ext_func f2 4
void f1()
{
}
void f2()
{
}
#pragma ext_func f1 3 means that the branch destination to function f1 is located in branch table address
4000H + 4*32 + 4*3.
#pragma ext_func f2 4 means that the branch destination to function f2 is located in branch table address
4000H + 4*32 + 4*4.
4*32 bytes from the beginning of the branch table is exclusively for interrupt functions (including the startup
routine).
(Output object of compiler)
(1) Boot area side (without -ZF specification)
@@CODE
CSEG
_func:
call
!0408CH
call
!04090H
ret
(2) Flash area side (with -ZF specification)
@ECODE
CSEG
_f1:
ret
_f2:
ret
@EXT03
CSEG
AT
0408CH
br
!!_f1
br
!!_f2
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(36) Firmware ROM function
Firmware ROM Function
_ _flash
Caution Do not use this flash function for devices that have no flash area self-rewrite function.
Operation is not guaranteed if it is used.
This function enables the flash memory rewrite function of devices.
FUNCTIONS
This calls a firmware ROM function that self-writes to the flash memory via the interface library positioned
between the firmware ROM function and the C language function.
In the interface library call interface, the first argument is passed via the register and the second and
subsequent arguments are transferred to the stack. The first argument's register is as follows.
1, 2-byte integer
AX
3-byte integer
WHL
4-byte integer
AX (lower integer), RP2 (higher integer)
The size of the pointer passed to the stack after the second argument is three bytes.
EFFECT
Operations related to the firmware ROM function can be described at the C source level.
USAGE
_ _flash attributes are added to the top during an interface library prototype declaration.
RESTRICTIONS
Function calls by a function pointer are not supported.
When the old specification function interface specification option (-ZO) is specified, it results in an error.
When a function with _ _flash is defined, it results in an error.
COMPATIBILITY
From another C compiler to this C compiler
Modification is not required if the reserved word _ _flash is not used.
When changing the firmware ROM function, modify the program according to the method above.
From this C compiler to another C compiler
Possible using #define (refer to 11.6 Modifications of C Source).
In a CPU with a firmware ROM function or substitute function, it is necessary for the user to create an
exclusive library to access that area.
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(37) Method of int expansion limitation of argument/return value
Method of int Expansion Limitation of Argument/Return Value
-ZB
FUNCTION
When the type definition of the function return value is char/unsigned char, the int expansion code of the
return value is not generated.
When the prototype of the function argument is defined and the argument definition of the prototype is
char/unsigned char, the int expansion code of the argument is not generated.
EFFECT
The object code is reduced and the execution speed improved since the int expansion codes are not
generated.
USAGE
The -ZB option is specified during compilation.
EXAMPLE
(C source)
unsigned char func1 (unsigned char x, unsigned char y);
unsigned char c, d, e;
void main ()
{
c = func1 (d, e);
c = func2 (d, e);
}
unsigned char func1 (unsigned char x, unsigned char y)
{
return x + y;
}
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Method of int Expansion Limitation of Argument/Return Value
-ZB
(Output object of compiler)
When -ZB is specified
_main:
; line 5:
c = func1 (d, e);
mov
x, !!_e
;
Do not execute int expansion
push
ax
;
Do not execute int expansion
mov
x, !!_d
call
$!_func1
pop
ax
mov
!!_c,c
; line 6
c = func2 (d, e);
mov
x, !!_e
mov
a, #00H ; 0
;
Execute int expansion since there is no prototype declaration
push
ax
mov
x, !!_d
call
!!_func2
pop
ax
mov
!!_c,c
; line 7:
}
ret
RESTRICTIONS
If the files are different between the definition of the function body and the prototype declaration to this
function, the program may operate incorrectly.
COMPATIBILITY
From another C compiler to this C compiler
If the prototype declarations for all definitions of function bodies are not correctly performed, perform
correct prototype declaration. Alternatively, do not specify the -ZB option.
From this C compiler to another C compiler
No modification is required.
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(38) Memory manipulation function
Memory Manipulation Function
#pragma inline
FUNCTION
An object file is generated by the output of the standard library memory manipulation functions memcpy,
memset, memchr, and memcmp with direct inline expansion instead of function call.
When there is no #pragma directive, the code that calls the standard library functions is generated.
EFFECT
Compared with when a standard library function is called, the execution speed is improved.
Object code is reduced if a constant is specified for the specified character number.
USAGE
The function is described in the source in the same format as a function call.
The following items can be described before #pragma inline.
Comments
Other #pragma directives
Preprocessing directives that do not generate variable definitions/references or function
definitions/references
EXAMPLE
(C source)
#pragma inline
char ary1[100], ary2[100];
void main()
{
memset(ary1, `A', 50);
memcpy(ary1, ary2, 50);
}
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Memory Manipulation Function
#pragma inline
(Output object of compiler)
When -MS is specified
_main:
; line 7 : memset(ary1, 'A', 50);
movw de,#_ary1
mov c,#032H ; 50
mov a,#041H ; 65
mov [de+],a
dbnz c,$$-1
; line 8 : memcpy(ary1, ary2, 50);
movw de,#_ary1
mov c,#032H ; 50
movw hl,#_ary2
mov a,[hl+]
mov [de+],a
dbnz c,$$-2
; line 9 :
; line 10 : p = memchr(ary1, 'B', 50);
mov c,#032H ; 50
movw de,#_ary1
mov a,#042H ; 66
cmp a,[de]
bz $L0006
incw de
dbnz c,$$-5
subw de,de
L0006:
movw !_p,de
; line 11 : i = memcmp(ary1, ary2, 100);
mov c,#064H ; 100
movw de,#_ary1
movw hl,#_ary2
mov a,[de+]
sub a,[hl+]
bnz $L0008
dbnz c,$$-5
L0008:
subc x,x
xch a,x
movw !_i,ax
; line 12 : }
ret
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Memory Manipulation Function
#pragma inline
(Output object of compiler)
When -MM is specified
_main:
; line 7 : memset(ary1, 'A', 50);
movw de,#LOWW _ary1
mov c,#032H ; 50
mov a,#041H ; 65
mov [de+],a
dbnz c,$$-1
; line 8 : memcpy(ary1, ary2, 50);
movw de,#LOWW _ary1
mov c,#032H ; 50
movw hl,#LOWW _ary2
mov w,#0FH ; 15
mov a,[hl+]
mov [de+],a
dbnz c,$$-2
; line 9 :
; line 10 : p = memchr(ary1, 'B', 50);
mov c,#032H ; 50
movw de,#LOWW _ary1
mov a,#042H ; 66
cmp a,[de]
bz $L0006
incw de
dbnz c,$$-5
subw de,de
L0006:
movw !!_p,de
; line 11 : i = memcmp(ary1, ary2, 100);
mov c,#064H ; 100
movw de,#LOWW _ary1
movw hl,#LOWW _ary2
mov w,#0FH ; 15
mov a,[de+]
sub a,[hl+]
bnz $L0008
dbnz c,$$-5
L0008:
subc x,x
xch a,x
movw !!_i,ax
; line 12 : }
ret
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Memory Manipulation Function
#pragma inline
(Output object of compiler)
When -ML is specified
_main:
; line 7 : memset(ary1, 'A', 50);
movg tde,#_ary1
mov c,#032H ; 50
mov a,#041H ; 65
mov [de+],a
dbnz c,$$-1
; line 8 : memcpy(ary1, ary2, 50);
movg tde,#_ary1
mov c,#032H ; 50
movg whl,#_ary2
mov a,[hl+]
mov [de+],a
dbnz c,$$-2
; line 9 :
; line 10 : p = memchr(ary1, 'B', 50);
mov c,#032H ; 50
movg tde,#_ary1
mov a,#042H ; 66
cmp a,[de]
bz $L0006
incg tde
dbnz c,$$-6
subg tde,tde
L0006:
movg !!_p,tde
; line 11 : i = memcmp(ary1, ary2, 100);
mov c,#064H ; 100
movg tde,#_ary1
movg whl,#_ary2
mov a,[de+]
sub a,[hl+]
bnz $L0008
dbnz c,$$-5
L0008:
subc x,x
xch a,x
movw !!_i,ax
; line 12 : }
ret
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Memory Manipulation Function
#pragma inline
COMPATIBILITY
From another C compiler to this C compiler
Modification is not required if the memory manipulation function is not used.
When changing the memory manipulation function, modify the program according to the method above.
From this C compiler to another C compiler
Delete the #pragma inline directive or delimit it with #ifdef.
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(39) callf two-step branch function
callf Two-Step Branch Function
-ZG
FUNCTION
A function body to which the callf/_ _callf attribute is added is not allocated to the callf area from 800H to
0FFFH, a branch instruction to the function body is allocated to the callf area, and the code to call the branch
instruction using the callf instruction is generated.
EFFECT
Compared to the case when allocating a function body to the callf area, the callf/_ _callf attribute can be
added to many more functions. Therefore, this function can shorten the object code if many functions that
include call functions are frequently used.
USAGE
The -ZG option is specified during compilation.
RESTRICTIONS
Modules in which the -ZG option is specified and modules in which the -ZG option is not specified cannot be
linked.
The two-step branch table consumes 4 bytes per function when the -MM/ML option is specified, and 3 bytes
when the -MS option is specified. The maximum number of callf functions that can be allocated when the
-ZG option is specified per load module and the total number of callf functions per linked module are as
follows.
- When the -MM/ML option is specified: 512
- When the -MS option is specified:
682
EXAMPLE
(C source 1)
_ _callf extern int fsub();
void main()
{
int ret_val;
ret_val = fsub();
}
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callf Two-Step Branch Function
-ZG
(C source 2)
_ _callf int fsub()
{
int val = 1;
return val;
}
(Output object of compiler)
With large or medium model
(C source 1)
EXTRN ?fsub ;
Declaration
callf !?fsub ;
Call
(C source 2)
PUBLIC _fsub ;
Declaration
PUBLIC ?fsub ;
Declaration
@@CALF CSEG FIXED
?fsub: br !!_fsub ;
Branch table
@@CODE CSEG
_fsub:
;
Function definition
.
.
Function body
.
.
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callf Two-Step Branch Function
-ZG
(Output object of compiler)
With small model
(C source 1)
EXTRN ?fsub ;
Declaration
Callf !?fsub ;
Call
(C source 2)
PUBLIC _fsub ;
Declaration
PUBLIC ?fsub ;
Declaration
@@CALFS CSEG FIXEDA
?fsub: br !_fsub ;
Branch table
@@CODES CSEG BASE ;
Function definition
_fsub:
.
.
Function body
.
.
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(40) Automatic callf functionization of function call interface
Automatic Callf Functionization of Function Call Interface
-ZH
FUNCTION
The _ _callf attribute is added to all functions except for the callt/_ _callt/_ _interrupt/_ _interrupt_brk/_
_rtos_interrupt functions.
USAGE
The -ZH option is specified during compilation.
RESTRICTIONS
The -ZF option for the flash area allocation specification cannot be specified at the same time.
If specified, a warning message is output and the -ZH option is ignored.
The standard library that supports the -ZF option is not available. Sources that include the standard library
cannot be linked using the -ZF option during compilation.
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(41) Three-byte address reference/generation function
Three-Byte Address Reference/Generation Function #pragma addraccess
FUNCTION
A code that references the highest byte and the lower 2 bytes of a 3-byte address, and a code that generates
a 3-byte address from the value of the highest byte and the lower 2 bytes are output to an object directly with
inline expansion and an object file is created.
If the #pragma directive is not added, the three-byte address reference/generation function is regarded as an
ordinary function.
EFFECT
Three-byte address reference/generation can be performed with a short code without using a complex cast
description.
USAGE
Describe the #pragma addraccess directive at the beginning of the C source.
Describe the #pragma addraccess directive in the C source in the same manner as a function call.
The following items can be described before the #pragma addraccess directive.
(1) Comments
(2) Other #pragma directives
(3) Among the preprocessing directives, those that do not generate a variable definition/reference or
function definition/reference.
The keywords following #pragma addraccess can be described in either uppercase or lowercase letters.
The following three names can be used for the three-byte address reference/generation function name.
FP_SEG
FP_OFF
MK_FP
[List of function names for three-byte address reference/generation]
(1) unsigned char FP_SEG(void *addr);
The value of the most significant byte of a three-byte address pointed by addr is obtained.
(2) unsigned int FP_OFF(void *addr);
The values of the lower 2 bytes of a three-byte address pointed by addr are obtained.
(3) void *MK_FP(unsigned char seg, unsigned int offset);
The address value of the three-byte address having the value pointed by seg as the most significant byte, and
the value pointed by offset as the lower 2 bytes.
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Three-Byte Address Reference/Generation Function #pragma addraccess
RESTRICTIONS
The function names for three-byte address reference/generation cannot be used as the function names.
Describe the three-byte address reference/generation function in uppercase letters. If lowercase letters are
used, it is regarded as an ordinary function.
When the small or medium model is specified, #pragma addraccess is ignored and the three-byte address
reference/generation function is not supported.
EXAMPLE
#pragma addraccess
unsigned char seg;
unsigned int offset;
unsigned char ary[10];
unsigned char *p;
void main()
{
seg = FP_SEG(ary);
/*
Most significant byte value */
offset = FP_OFF(ary);
/*
Value of lower 2 bytes */
p = MK_FP(seg, offset);
/*
Generates 3-byte address */
}
(Output object of compiler)
@@CODE CSEG
_main:
; line 8 : seg = FP_SEG(ary);
/*
Most significant byte value */
mov a,#HIGHW _ary
mov !!_seg,a
; line 9 : offset = FP_OFF(ary);
/*
Value of lower 2 bytes */
movw ax,#LOWW _ary
movw !!_offset,ax
; line 10 :
; line 11 : p = MK_FP(seg, offset);
/*
Generates 3-byte address */
mov a,!!_seg
mov w,a
movw hl,!!_offset
movg !!_p,whl
; line 12 : }
ret
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Three-Byte Address Reference/Generation Function
#pragma addraccess
COMPATIBILITY
From another C compiler to this C compiler
Modification is not required if the three-byte address reference/generation function is not used.
When specifying the three-byte address reference/generation function, modify the function according to
the method above.
From this C compiler to another C compiler
Delete
the
#pragma addraccess statement or delimit it with #ifdef.
The three-byte address reference/generation function name can be used as the function name.
When specifying the three-byte address reference/generation function, modify the function conforming to
the specification of the C compiler.
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(42) Absolute address allocation specification
Absolute Address Allocation Specification
_ _directmap
FUNCTION
The initial value of an external variable declared by _ _directmap and a static variable in a function is
regarded as the allocation address specification, and variables are allocated to the specified addresses.
The _ _directmap variable in the C source is treated as an ordinary variable.
Because the initial value is regarded as the allocation address specification, the initial value cannot be
defined and remains an undefined value.
The specifiable address specification range, secured area range linked by the module for securing the area
for the specified addresses, and variable duplication check range are shown below.
With small model
Address Specification Range
Secured Area Range
Duplication Check Range
0x80 to 0xFFFF
0xFD00 to 0xFEFF
0xF000 to 0xFEFF
With large model (-CS0 specified)
Address Specification Range
Secured Area Range
Duplication Check Range
0x80 to 0xFFFFFF
0xFD00 to 0xFEFF
0xF000 to 0xFEFF
With large model (-CS15 specified)
Address Specification Range
Secured Area Range
Duplication Check Range
0x80 to 0xFFFFFF
0xFFD00 to 0xFFEFF
0xFF000 to 0xFFEFF
With medium model (-CS0 specified)
Address Specification Range
Secured Area Range
Duplication Check Range
0xF000 to 0xFFFF
0xFD00 to 0xFEFF
0xF000 to 0xFEFF
With medium model (-CS15 specified)
Address Specification Range
Secured Area Range
Duplication Check Range
0xFF000 to 0xFFFFF
0xFFD00 to 0xFFEFF
0xFF000 to 0xFFEFF
If the address specification is outside the address specification range, an F799 error is output.
If the allocation address of a variable declared by _ _directmap is duplicated and is within the duplication
check range, a W762 warning message is output and the name of the duplicated variable is displayed.
If the address specification range is inside the saddr1 area, the _ _sreg1 declaration is made automatically
and the saddr1 instruction is generated. If the address specification range is inside the saddr2 area, the _
_sreg declaration is made automatically and the saddr2 instruction is generated.
When the -CSA option is specified, a W338 warning message is output and the _ _directmap declaration in
the file is ignored.
EFFECT
One or more variables can be allocated to the same arbitrary address.
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Absolute Address Allocation Specification
_ _directmap
USAGE
Declare _ _directmap in the module in which the variable to be allocated in an absolute address is to be
defined.
_ _directmap
Type name Variable name
= Allocation address specification;
_ _directmap static
Type name
Variable name
= Allocation address specification;
_ _directmap _ _sreg
Type name
Variable name
= Allocation address specification;
_ _directmap _ _sreg
static
Type name
Variable name = Allocation address specification;
_ _directmap _ _sreg1
Type name
Variable name
= Allocation address specification;
_ _directmap _ _sreg1 static
Type name
Variable name = Allocation address specification;
If _ _directmap is declared for a structure/union/array, specify the address in braces {}.
_ _directmap does not have to be declared in a module in which a _ _directmap external variable is
referenced, so only declare extern.
extern
Type name Variable name;
extern
_ _sreg
Type name
Variable name;
extern
_ _sreg1
Type name
Variable name;
To generate the saddr2 instruction in a module in which a _ _directmap external variable allocated inside the
saddr2 area is referenced, _ _sreg must be used together to make extern_ _sreg Type name Variable
name;.
To generate the saddr1 instruction in a module in which a _ _directmap external variable allocated inside the
saddr1 area is referenced, _ _sreg1 must be used together to make extern_ _sreg1 Type name Variable
name;.
EXAMPLE
(C source)
_ _directmap char c = 0xff000;
_ _directmap _ _sreg char d = 0xffd20;
_ _directmap _ _sreg char e = 0xffd21;
_ _directmap struct x
char a;
char b;
char c;
} xx = {0xffe30};
void main()
{
c = 1;
d = 0x12;
e.5 = 1;
xx.a = 5;
xx.c = 10;
}
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Absolute Address Allocation Specification
_ _directmap
(Output object)
PUBLIC _c
PUBLIC _d
PUBLIC _e
PUBLIC _xx
PUBLIC _main
_c EQU 0FF000H
;
Addresses for variables declared by _ _directmap
_d EQU 0FFD20H
;
are defined by EQU
_e EQU 0FFD21H
;
_xx EQU 0FFE30H
;
EXTRN _ _mffd20
;
EXTRN output for linking secured area modules
EXTRN _ _mffd21
;
EXTRN _ _mffe30
;
EXTRN _ _mffe31
;
EXTRN _ _mffe32
;
@@CODE CSEG
_main:
; line 11 : c = 1
;
mov !_c,#01H
;
1
; line 12 : d = 0x12
;
mov _d,#012H
;
saddr2 instruction output because address
; line 13 : e.5 = 1
;
specified in saddr2 area
set1 _e.5
;
Bit manipulation possible because _ _sreg also used
; line 14 : xx.a = 5
;
mov _xx,#05H
;
saddr1 instruction output because address specified
; line 15 : xx.c = 10
;
in saddr1 area
mov _xx+2,#0AH
;
saddr1 instruction output because address specified
;
in saddr1 area
; line 16 : }
ret
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Absolute Address Allocation Specification
_ _directmap
RESTRICTIONS
_ _directmap cannot be specified for function arguments, return values, or automatic variables. If it is
specified in these cases, an error occurs.
If an address outside the secured area range is specified, the variable area will not be secured, making it
necessary to either describe a directive file or create a separate module for securing the area.
COMPATIBILITY
From another C compiler to this C compiler
Modification is not required if the keyword _ _directmap is not used.
When changing to the _ _directmap variable, modify the program according to the method above.
From this C compiler to another C compiler
Compatibility can be attained using #define (refer to 11.6 Modifications of C Source for details).
When _ _directmap is being used as the absolute address allocation specification, modify the program
according to the specifications of each compiler.
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11.6 Modifications of C Source
By using the extended functions of this C compiler, efficient object generation can be realized. However, these
extended functions are intended to cope with the 78K/IV Series. So, to use them for other devices, the C source may
need to be modified. Here, how to make the C source portable from another C compiler to this C compiler and vice
versa is explained.
From another C compiler to this C compiler
#pragma
Note
If the other C compiler supports the #pragma preprocessing directive, the C source must be modified. The
method and extent of modifications to the C source depend on the specifications of the other C compiler.
Extended specifications
If the other C compiler has extended specifications such as addition of keywords, the C source must be
modified. The method and extent of modifications to the C source depend on the specifications of the other C
compiler.
Note #pragma is one of the preprocessing directives supported by ANSI. The character string following
#pragma is identified as a directive to the compiler. If the compiler does not support this directive, the
#pragma directive is ignored and compilation will continue until it properly ends.
From this C compiler to another C compiler
Because this C compiler has added keywords as the extended functions, the C source must be made portable to
the other C compiler by deleting such keywords or delimiting them with #ifdef.
EXAMPLE
<1> To invalidate a keyword (same applies to callf, sreg, noauto, and norec etc.)
#ifndef
_ _K4_ _
#define callt
/* makes callt an ordinary function */
#endif
<2> To change from one type to another
#ifndef
_ _K4_ _
#define bit char
/* changes bit type to char type variable */
#endif
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11.7 Function Call Interface
The following items will be explained concerning the interface between functions when a function is called.
1. Return value (common in all the functions)
2. Ordinary function call interface
Passing arguments
Location and order of storing arguments
Location and order of storing automatic variables
3. noauto function call interface
Passing arguments
Location and order of storing arguments
Location and order of storing automatic variables
4. norec function call interface
Passing arguments
Location and order of storing arguments
Location and order of storing automatic variables
5. Pascal function call interface
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11.7.1 Return value
The function called stores the return value in the registers and carry flags as shown in Table 11-27.
Table 11-27. Storage Location of Return Values
Model
Type
Small Model
Medium Model
Large Model
1-byte integer
2-byte integer
BC
BC
BC
4-byte integer
BC (Lower)
RP2 (Higher)
BC (Lower)
RP2 (Higher)
BC (Lower)
RP2 (Higher)
Pointer
BC
BC (data pointer)
WHL (function pointer)
TDE
Structure, union
BC (structure copied to the
area specific to the function,
the start address of the union)
BC (structure copied to the
area specific to the function,
the start address of the union)
TDE (structure copied to the
area specific to the function,
the start address of the union)
1 bit
CY (carry flag)
CY (carry flag)
CY (carry flag)
Floating-point number
(float type)
BC (Lower)
RP2 (Higher)
BC (Lower)
RP2 (Higher)
BC (Lower)
RP2 (Higher)
Floating-point number
(double type)
BC (Lower)
RP2 (Higher)
BC (Lower)
RP2 (Higher)
BC (Lower)
RP2 (Higher)
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11.7.2 Ordinary function call interface
When all the arguments are allocated to registers and there is no automatic variable, the ordinary function call
interface is the same as noauto function call interface.
(1) Passing arguments
(a) When the -ZO option is not specified (default)
On the function call side, both the arguments declared with registers and the ordinary arguments are
passed in the same manner. The second and subsequent arguments are passed via a stack, and the first
argument is passed via a register or stack.
The location where the first argument is passed is shown in Table 11-28.
Table 11-28. Location Where First Argument Is Passed (On Function Call Side)
Option
Type
When -ZO Is Not Specified
When -ZO Is Specified
1-byte integer
Note
2-byte integer
AX
Passed via a stack
3-byte integer
WHL
Small model is passed via a stack
Passed via a stack
4-byte integer
Note
AX, RP2
Passed via a stack
Floating-point number (float type)
AX, RP2
Passed via a stack
Floating-point number (double type)
AX, RP2
Passed via a stack
Other
Passed via a stack
Passed via a stack
Note 1- to 4-byte data includes structures, unions, and pointers.
(b) When the -ZO option is specified
On the function call side, arguments declared with a register are passed via a register, and ordinary
arguments are passed via a stack. For the registers used for passing, refer to Table 11-30.
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(2) Location and order of storing arguments
There are two types of arguments: arguments allocated to registers and ordinary arguments. Arguments
allocated to registers are the arguments declared with registers and the arguments when -QV is specified.
The arguments not allocated to registers are allocated to stacks. The arguments allocated to stacks are
placed on the stack sequentially from the last argument.
(a) When the -ZO option is not specified
Saving and restoring registers to which arguments are allocated is performed on the function definition
side.
When -QV option is specified, the ordinary arguments are also allocated to registers regarding they are
declared with registers.
The ordinary arguments are allocated to a stack. When the arguments are passed via stacks, the area
where the arguments are passed (stack) is used as the area to which arguments are allocated.
On the function definition side, the arguments that are passed via a register or stack are stored in the area
to which arguments are allocated.
Arguments with more references together with register variables are allocated to registers. When the -QF
and -ML options are specified, however, a second or subsequent argument whose size is less than 4-bytes
and number of references is two or less is not always allocated to a register.
Table 11-29. List of Storing Arguments (On Function Definition Side, When -ZO Is Not Specified)
Model
Option
Small Model, Medium Model
Note
Large Model
When -QF is specified
RP3, VP, UP
RP3, VVP, UUP
When -QF is not specified
RP3, VP
RP3, VVP
Note With the medium model, the function pointer (3 bytes) cannot be used as a register argument.
(Order of allocation)
With small model, medium model, when -QF is specified
char, int, short, enum type: If there is long, float, double type argument, in the order of UP, RP3, VP
char, int, short, enum type: If there is no long, float, double type argument, in the order of RP3, UP,
VP
Pointer type:
In the order of UP, VP, RP3
long, float, double type:
RP3 (lower), VP (higher)
With small model, medium model, when -QF is not specified
char, int, short, enum type: In the order of RP3, VP
Pointer type:
In the order of VP, RP3
long, float, double type:
RP3 (lower), VP (higher)
With large model, when -QF is specified
char, int, short, enum type: If there is long, float, double type argument, in the order of UP, RP3, VP
char, int, short, enum type: If there is no long, float, double type argument, in the order of RP3, UP,
VP
Pointer type:
In the order of UUP, VVP
long, float, double type:
RP3 (lower), VP (higher)
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With large model, when -QF is not specified
char, int, short, enum type: In the order of RP3, VP
Pointer type:
In the order of VVP
long, float, double type:
RP3 (lower), VP (higher)
(b) When the -ZO option is specified
The locations where arguments are passed on the function call side and the function definition side are the
location where arguments are allocated.
As long as there are allocable registers, the arguments declared with registers are allocated to registers.
The saving and restoring of registers to which arguments are allocated is performed before and after the
function call.
Table 11-30. List of Storing Arguments (On Function Definition Side, When -ZO Is Specified)
Model
Option
Small Model
Large Model
When -QF is specified
RP3, VP, UP
RP3, VVP
When -QF is not specified
RP3, VP
RP3, VVP
(Order of allocation)
With small model, when -QF is specified
char, int, short, enum type: in the order of RP3, VP, UP
Pointer type:
In the order of VP, UP , RP3
long, float, double type:
RP3 (lower), VP (higher)
With small model, when -QF is not specified
char, int, short, enum type: In the order of RP3, VP
Pointer type:
In the order of VP, RP3
long, float, double type:
RP3 (lower), VP (higher)
With large model
char, int, short, enum type: In the order of RP3, VP
Pointer type:
In the order of VVP
long, float, double type:
RP3 (lower), VP (higher)
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(3) Location and order of storing automatic variables
There are two types of automatic variables: automatic variables to be allocated to registers and ordinary
automatic variables. The automatic variables to be allocated to registers are the ones that are declared with
registers and the automatic variables when -QV is specified. They are allocated to register _@KREGXX as
long as there are allocable registers and _@KREGXX. However, the automatic variables are allocated to
_@KREGXX only when -QR is specified.
The automatic variables allocated to registers and _@KREGXX are called register variables hereafter.
For _@KREGXX, refer to APPENDIX A LIST OF LABELS FOR saddr AREA.
The register variables are allocated after register arguments are allocated. Therefore, the register variables
are allocated to registers when there are excess registers after the allocation of register arguments.
The automatic variables not allocated to registers are allocated to stacks.
The saving and restoring of registers and _@KREGXX to allocate automatic variables is performed on the
function definition side.
(Order of allocating automatic variables)
The order of allocating automatic variables to registers are the same as the order of allocating arguments.
For the details, refer to the order of allocating arguments.
The automatic variables allocated to _@KREGXX are allocated in the order of declaration.
The automatic variables allocated to stacks are placed on the stack in the order of declaration.
The following shows an example of the interface above.
EXAMPLE 1
(C source)
void func0 (register int, int);
void main () {
func0 (0x1234, 0x5678);
}
void func0 (register int p1, int p2) {
register int r;
int a;
r = p2;
a = p1;
}
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(Output code) With large model, when -QF is specified and -ZO is not specified
@@CODE
CSEG
_main:
movw
ax,#05678H
;22136
push
ax
;
Arguments passed via stack
movw
ax,#01234H
;4660
;
The first argument is passed via register
call
$!_func0
;
Function call
pop
ax
;
Arguments passed via stack
ret
_func0:
push
uup
;
Save registers for register variables/arguments
push
rp3
;
push
vvp
;
movw
rp3,ax
;
Allocate register arguments to rp3
movw
ax,[sp+11]
;p2
;
Argument p2 to be passed via a stack
movw
up,ax
;
Register variable r (up)
movw
vp,rp3
;
Register argument p1 (rp3) variable a (vp)
pop
vvp
;
Restores register for register variables/arguments
pop
rp3
pop
uup
ret
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11.7.3 noauto function call interface
(1) Passing arguments
(a) When the -ZO option is not specified (default)
On the function call side, the arguments declared with registers and the ordinary arguments are passed in
the same manner. The second and subsequent arguments are passed via a stack. The first argument is
passed via a register or a stack (in the same manner as ordinary functions).
For the location where the first argument is passed, refer to Table 11-28.
(b) When the -ZO option is specified
Arguments are passed via registers. For the registers to be used, refer to Table 11-13.
(2) Location and order of storing arguments
On the function definition side, all the arguments are allocated to registers.
If there is an argument that cannot be allocated to a register, an error occurs.
(a) When the -ZO option is not specified (default)
On the function definition side, the arguments passed via registers or stacks are copied to registers. Even
when the arguments are passed via registers, the processing to copy the register is output because the
register on the function call side (passing side) and the function definition side (receiving side) are different.
For the registers allocated on the function definition side, refer to Table 11-14.
The saving and restoring of the register to which arguments are allocated is performed on the function
definition side.
(Order of allocation)
The order is the same as an ordinary function with -QF specified.
(b) When the -ZO option is specified
The locations where arguments are passed on the function call side and the function definition side are the
same as the locations where arguments are allocated.
The saving and restoring of registers to which arguments are allocated is performed before and after the
function call.
(Order of allocation)
The order is the same as for ordinary functions.
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(3) Location and order of storing automatic variables
(a) When the -ZO option is not specified (default)
Automatic variables are allocated to registers and _@KREGXX. However, the automatic variables are
allocated to _@KREGXX only when -QR is specified. For _@KREGXX, refer to APPENDIX A LIST OF
LABELS FOR saddr AREA.
Automatic variables are allocated to registers when there are excess registers after the allocation of
arguments. When -QR is specified, automatic variables are allocated also to _@KREGXX.
If an automatic variable cannot be allocated to registers and _@KREGXX, an error occurs.
The saving and restoring of the register and _@KREGXX to which automatic variables is allocated are
performed in the function definition side.
(Order of allocation)
The order of allocating automatic variables to registers are the same as the order of allocating arguments.
The automatic variables allocated to _@KREGXX are allocated in the order of declaration.
(b) When the -ZO option is specified.
Allocation cannot be performed because the automatic variables cannot be described.
The following shows an example of the interface above.
EXAMPLE
(C source)
noauto void func2 (int, int);
void main ( ) {
func2 (0x1234, 0x5678);
}
noauto void func2 (int p1, int p2) {
/*
function body */
}
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(Output code) With small model, when -ZO is specified
@@CODES
CSEG
BASE
_main:
push
rp3,vp
;
Save registers for arguments
movw
rp3,#01234H
;4660
;
Allocate arguments to rp3
movw
vp,#05678H
;22136
;
Allocate arguments to vp
call
!_func2
;
Function call
pop
rp3,vp
;
Restore registers for arguments
ret
_func2:
ret
(Output code) With small model, when -ZO is not specified
@@CODES
CSEG
BASE
_main:
movw
ax,#05678H
; 22136
push
ax
;
Arguments passed via stack
movw
ax,#01234H
; 4660
;
The first argument is passed via register
call
!_func2
;
Function call
pop
ax
;
Arguments passed via stack
ret
_func2:
push
rp3,up
;
Save registers for arguments
movw
rp3,ax
;
Allocate arguments to rp3
movw
ax,[sp+7]
;
Argument passed via stack received by register
movw
up,ax
;
Allocate arguments to up
pop
rp3, up
;
Restore registers for arguments
ret
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11.7.4 norec function call interface
(1) Passing arguments
(a) When the -ZO option is not specified (default)
On the function call side, arguments are passed via registers and _@NRARGX. For the registers, refer to
Table 11-17 Registers Used for norec Function Arguments: Passing Side (Without -ZO).
(b) When the -ZO option is specified
On the function call side, arguments are passed via a register and _@NRARGX. If the arguments cannot be
passed via registers any more, they are passed only via _@NRARGX instead of via registers. Arguments are
never passed via registers and _@NRARGX together.
(2) Location and order of storing arguments
On the function definition side, all the arguments are allocated to registers and _@NRARGX. However,
arguments are allocated to _@NRARGX only when -QR is specified. For _@NRARGX, refer to APPENDIX A
LIST OF LABELS FOR saddr AREA.
If there is an argument that cannot be allocated to registers and _@NRARGX, an error occurs.
(a) When the -ZO option is not specified (default)
On the function definition side, the arguments passed via registers are copied to registers. Even when the
arguments are passed via registers, copying the register is necessary because the register on the function
call side (passing side) and the function definition side (receiving side) are different.
When the arguments are passed via _@NRARGX, the locations where arguments are passed are the same
as the locations where arguments are allocated.
If the arguments cannot be passed via registers any more, they are passed also via _@NRARGX. Arguments
are passed via registers and _@NRARGX together.
The saving and restoring of the register to which arguments are allocated is performed in the function
definition side. For the location of storing arguments, refer to Table 11-18 Registers Used for norec
Function Arguments: Receiving Side (Without -ZO).
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Table 11-31. List of Registers Passing/Receiving norec Arguments (When -ZO Is Not Specified)
Model
Type
Small Model, Medium Model
Note 1
Large Model
Note 2
The first argument is char type
Passed via C, DE, RP2
Received via R6, R7, VP, UP
Passed via C, TDE, RP2
Received via R6, R7, VVP, UP
The first arguments is not char type
Passed via AX, DE, RP2
Received via RP3, VP, UP
Passed via AX, TDE, RP2
Received via RP3, VVP, UP
Notes 1.
With the medium model, the function pointer (3 bytes) cannot be used via a register. When -QR is
specified, however, it can be passed via _@NRARGX.
2.
With the large model, only one pointer (3 bytes) can be passed/received via a register. When -QR is
specified, however, it can be passed/received also via _@NRARGX.
(Order of allocation)
With small model, medium model
char, int, short, enum type:
If there is long, float, double type argument, in the order of UP, RP3, VP
If there is no long, float, double type argument, in the order of RP3, UP,
VP
Pointer type:
In the order of UP, VP, RP3
long, float, double type:
RP3 (lower), VP (higher)
With large mode
char, int, short, enum type:
If there is long, float, double type argument, in the order of UP, RP3, VP
If there is no long, float, double type argument, in the order of RP3, UP,
VP
Pointer type:
VVP
long, float, double type:
RP3 (lower), VP (higher)
(b) When the -ZO option is specified
The same as the noauto function call interface
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(3) Location and order of storing automatic variables
(a) When the -ZO option is not specified
The automatic variables are allocated to registers and _@NRARGX as long as there are allocable registers
and _@NRARGX. If there is no allocable register any more, they are allocated to _@NRATXX.
However, automatic variables are allocated to _@NRARGX and _@NRATXX only when -QR is specified.
For _@NRATXX, refer to APPENDIX A LIST OF LABELS FOR saddr AREA
If there is an automatic variable that cannot be allocated to registers, _@NRARGX and _@NRATXX, an error
occurs.
The saving and restoring of registers to which automatic variables are allocated is performed on the function
definition side.
(Order of allocating automatic variables)
The order of allocating automatic variables to registers is the same as the order of allocating noauto
function arguments. For details, refer to 11.7.3 noauto function call interface.
The automatic variables allocated to _@NRATXX are allocated in the order of declaration.
(b) When the -ZO option is specified
The automatic variables are allocated to registers as long as there are allocable registers. If there are no
more allocable registers, they are allocated to _@NRATXX.
Automatic variables are allocated to _@NRATXX only when -QR is specified. For _@NRATXX, refer to
APPENDIX A LIST OF LABELS FOR saddr AREA.
The automatic variables are allocated after arguments are allocated. Therefore, the automatic variables
are allocated to registers when there are excess registers after the allocation of arguments.
If there is an automatic variable that cannot be allocated to a register and _@NRATXX, an error occurs.
The saving and restoring of registers to allocate automatic variables is performed on the function definition
side.
(Order of allocating automatic variables)
The order of allocating registers to automatic variables is the same as the order of allocating noauto
function arguments. For details, refer to 11.7.3 noauto function call interface.
The automatic variables allocated to _@NRARGX and _@NRATXX are allocated in the order of
declaration.
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EXAMPLE
(C source)
norec
void func (int);
void main (void) {
func (0x34);
}
norec
void func (int p1) {
int a;
a = p1;
}
(Output code) With small model, when -QX2 and -ZO are specified
@@CODES CSEG
_main:
push
rp3
;
Save registers for arguments
movw
rp3,#034H; 52
;
Allocate arguments to RP3
call
$!_func3
;
Function call
pop
rp3
;
Restore registers for arguments
ret
_func:
push
vvp
;
Save the automatic variable register
movw
vp,rp3
;
a = p1
pop
vvp
;
Restore the automatic variable register
ret
(Output code) With small model, when -QX2 and -ZO is not specified
@@CODE
CSEG
_main:
movw
ax,#034H ;52
;
Transfers the argument at AX
call
$!_func
;
Function call
ret
_func:
push
uup
;
Save the automatic variable register
push
rp3
;
Save registers for arguments
movw rp3,ax
;
Store argument in RP3
movw
up,rp3
;
a = p1
pop
rp3
;
Restore registers for arguments
pop
uup
;
Restore the automatic variable register
ret
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11.7.5 Pascal function call interface
The difference between this function interface and other function interfaces is that the correction of stacks used for
loading of arguments when a function is called is done by the function side that was called, rather than the function
caller. All other points are the same as the function attributes specified at the same time.
[Area to which arguments are allocated]
[Sequence in which arguments are allocated]
[Area to which automatic variables are allocated]
[Sequence in which automatic variables are allocated]
If the noauto attribute is specified at the same time, the features are the same as when a noauto function is
called (Refer to 11.7.3 noauto function call interface).
If the noauto attribute is not specified at the same time, the features are the same when an ordinary function is
called (Refer to 11.7.2 Ordinary function call interface).
(C source)
_ _pascal void func0 (register int, int);
void main ()
{
func0 (0x1234, 0x5678);
}
_ _pascal void func0 (register int p1, int p2)
{
register int r;
int a;
r = p2;
a = p1;
}
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(Output code)
With small model (when -QF option is specified)
_main:
; line 4 : func0(0x1234, 0x5678);
movw ax,#05678H ; 22136
push ax ;
Argument is passed via a stack
movw ax,#01234H ; 4660 ;
The first argument is passed via a register
call !_func0 ;
Function call
;
Stack is not corrected here
ret
; line 6 : _ _pascal void func0(register int p1, int p2)
; line 7 : {
_func0:
push rp3,up ;
Saves the register for register variables
;
or register arguments
movw rp3,ax
;
Allocates a register argument to rp3
push ax ;
Reserves the area for automatic variable a
; line 8 : register int r;
; line 9 : int a;
; line 10 : r = p2;
movw ax,[sp+9]; p2
;
Argument p2 is passed via stack
movw up,ax ;
Register variable up
; line 11 : a = p1;
movw ax,rp3 ;
Register argument rp3
movw [sp+0],ax ; a ;
Automatic variable a
pop ax ;
Releases the area for automatic variable a
pop rp3,up ;
Restores the register for register variables
;
or register arguments
pop hl
;
Obtains the return address
incg sp
;
pop ax
;
The stack consumed by arguments passed via a
;
stack is corrected
br hl
;
Branch to the return address
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(C source)
With large model
_ _pascal noauto void func2(int, int);
void main ()
{
func2(0x1234, 0x5678);
}
_ _pascal noauto void func2(int p1, int p2)
{
...
}
(Output code)
With large model
_main:
; line 4 : func2(0x1234, 0x5678);
movw ax,#05678H ; 22136
push ax
;
Argument is passed via a stack
movw ax,#01234H ; 4660
;
The first argument is passed via a register
call $!_func2
;
Function call
;
Stack is not corrected here
ret
; line 6 : _ _pascal noauto void func2(int p1, int p2)
; line 7 : {
_func2:
push uup
;
Saves the register for arguments
push rp3
;
Saves the register for arguments
movw rp3,ax
;
Allocates a register argument to rp3
movw ax,[sp+8]
;
Argument passed via a stack and received by a register
movw up,ax
;
Allocates an argument to up
...
pop rp3
;
Restores the register for arguments
pop uup
;
Restores the register for arguments
pop whl
;
Obtains the return address
pop ax
;
The stack consumed by arguments passed via a stack is corrected
br whl
;
Branch to the return address
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CHAPTER 12 REFERENCING THE ASSEMBLER
This chapter describes how to link a program written in assembly language.
If a function called from a C source program is written in another language, both object modules are linked by the
linker. This chapter describes the procedure for calling a program written in another language from a program written
in the C language and the procedure for calling a program written in the C language from a program written in
another language.
How to interface with another language by using the RA78K4 assembler package and this C compiler is described
in the following order.
(1) Calling assembly language routines from C language
(2) Calling C language functions from assembly language
(3) Referencing variables defined in C language
(4) Referencing variables defined in assembly language on the C language side
(5) Cautions
CHAPTER 12 REFERENCING THE ASSEMBLER
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12.1 Accessing Arguments/Automatic Variables
The procedure for accessing arguments and automatic variables of this C compiler is described below.
On the function call side, register arguments are passed in the same way as ordinary arguments.
The first argument uses the following registers and stacks, and subsequent arguments are passed via
stacks.
Table 12-1. Passing Arguments (Function Call Side)
Type
Passing Location (First Argument)
Passing Location (Second and Later Arguments)
1-byte, 2-byte integer
AX
Stack passing
3-byte integer
WHL
(Stack passing in case of small model)
Stack passing
4-byte integer
AX, RP2
Stack passing
Floating-point number
AX, RP2
Stack passing
Others
Stack passing
Stack passing
Remark
1- to 4-byte data includes structures and unions.
On the function definition side, arguments passed via a register or stack are stored in the argument allocation
location.
Register arguments are copied to a register or saddr area (_@KREGxx).
Even when passing is done via a register, the registers on the function call side (passing side) and the
function definition side (receiving side) differ, and therefore register copying is performed.
Ordinary arguments passed via a register are placed on a stack on the function definition side.
If passing is done via a stack, the passing location simply becomes the argument allocation location.
Saving and restoring of registers that allocate arguments is performed on the function definition side.
The arguments of functions and the values of automatic variables declared inside functions are stored in the
following registers, saddr areas, or stack frames using an option.
The base pointer used when storing in a stack frame uses the UP register.
CHAPTER 12 REFERENCING THE ASSEMBLER
User's Manual U15556EJ1V0UM
472
Table 12-2. List of Storing Arguments/Automatic Variables (Inside Called Function)
Option
Argument/auto Variable
Storage Location
Priority Level
-QV
(register allocation
option)
Declared argument or
automatic variable
With small or medium
model RP3, VP, UP (only
when -QF is specified)
With large model
RP3, VVP, UUP (only
when -QF is specified)
-QR
register declared
automatic variable
With small or medium
model RP3, VP, UP (only
when -QF is specified)
With large model
RP3, VVP, UUP (only
when -QF is specified)
Automatic variable
_@KREGxx
-QRV
Declared argument or
automatic variable
With small or medium
model RP3, VP, UP (only
when -QF is specified)
With large model
RP3, VVP, UUP (only
when -QF is specified)
Automatic variable
_@KREGxx
Although the allocation order may vary
depending on the number of references, the
priority level is determined basically by the
following rules.
<1> With small or medium model
When -QF is specified
char, int, short, enum type: In the order of
UP, RP3, VP (if a long, float, or double type
argument exists)
In the order of RP3, UP, VP (if a long, float,
or double type argument does not exist)
Pointer type: In the order of UP, VP, RP3
long, float, or double type: RP3 (lower), VP
(higher)
When -QF is not specified
char, int, short, enum type: In the order of
RP3, VP
Pointer type: In the order of VP, RP3
long, float, or double type: RP3 (lower), VP
(higher)
<2> With large model
When -QF is specified
char, int, short, enum type: In the order of
UP, RP3, VP (if the long, float, or double
type argument exists)
In the order of RP3, UP, VP (if the long,
float, or double type argument does not
exist)
Pointer type: In the order of UUP, VVP,
long, float, or double type: RP3 (lower), VP
(higher)
When -QF is not specified
char, int, short, enum type: In the order of
RP3, VP
Pointer type: In the order of VVP
long, float, or double type: RP3 (lower), VP
(higher)
Default
Declared argument,
automatic variable
Stack frame
Order of appearance
CHAPTER 12 REFERENCING THE ASSEMBLER
User's Manual U15556EJ1V0UM
473
The following example shows the function call.
(C source: Large model with -QRF)
void func0(register int, int);
void main()
{
func0(0x1234, 0x5678);
}
void func0(register int p1, int p2)
{
register int r;
int a;
r = p2;
a = p1;
}
(Output assembler source)
PUBLIC _func0
PUBLIC _main
@@CODE CSEG
_main:
movw ax,#05678H ; 22136
push ax
;
Argument is passed via a stack
movw ax,#01234H ; 4660
;
The first argument is passed via a register
call $!_func0
;
Function call
pop ax
;
Argument is passed via a stack
ret
_func0:
push uup
;
Saves the register for arguments
push rp3
movw rp3,ax
;
Allocates register arguments p1 to rp3.
push ax
movw ax,[sp+10] ; p2
;
Argument
p2 passed via a stack is allocated to up
movw up,ax
movw ax,rp3
;
Register argument
p1 is assigned
movw [sp+0],ax ; a
;
to automatic variable a
pop ax
pop rp3
;
Restores the register for arguments
pop uup
ret
END
CHAPTER 12 REFERENCING THE ASSEMBLER
User's Manual U15556EJ1V0UM
474
12.2 Storing Return Values
Return values during function calls are stored in registers and carry flags.
The storage locations of return values are shown in the table below.
Table 12-3. Storage Location of Return Values
Type
Small Model
Medium Model
Large Model
1-byte integer
2-byte integer
BC
BC
BC
4-byte integer
BC (lower), RP2 (higher)
BC (lower), RP2 (higher)
BC (lower), RP2 (higher)
Pointer
BC
BC (data pointer)
WHL (function pointer)
TDE
Structure, union
BC (start address of structure or
union copied to function-specific
area)
BC (start address of structure
or union copied to function-
specific area)
TDE (start address of structure
or union copied to function-
specific area)
1 bit
CY
CY
Y
Floating-point number
BC (lower), RP2 (higher)
BC (lower), RP2 (higher)
C (lower), RP2 (higher)
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extern int FUNC (int, long);
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void main ( ) {
int
i, j;
long
l;
i = 1;
l = 0x54321;
j = FUNC (i, l);
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}
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passed to FUNC
i
High address
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@@DATA DSEG
_DT1: DS (2)
_DT2: DS (4)
@@CODE CSEG
_FUNC:
push uup
;save work registers
!
push rp3
push vvp
movw up,ax
;arg1
movw ax,[sp+11] ;arg2
movw rp3,ax
movw ax,[sp+13]
;arg2
movw vp,ax
movw !!_DT1,up
;move 1st argument(i)
movw !!_DT2,rp3
;move 2nd argument(l)
movw !!_DT2+2,vp
movw bc,#0AH ; 10
;set return value
!
pop vvp
;restore work registers
pop rp3
pop uup
ret
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BC register
Return value
16 bits or less
Higher word
RP2 register
Return value
17 bits or more
Lower word
BC register
CHAPTER 12 REFERENCING THE ASSEMBLER
User's Manual U15556EJ1V0UM
478
<6> Restoring the saved registers
The saved contents of the base pointer and work registers are restored.
<7> Returning control to main
Figure 12-2. Stack Area After Return
Higher word
Return address to main
l (Lower word)
l (Upper word)
Low address
Stack pointer
Stack area
High address
Word
Return value
BC register
or
RP2 register BC register
Lower word
The procedure for calling an assembly language from C and the processing of the assembly language routine
are illustrated in Figure 12-3.
Figure 12-3. Calling Assembly Language Routine from C
Return address to main
l (Lower word)
l (Higher word)
Low address
Stack pointer
Stack area
Arguments to be passed to FUNC
AX register
High address
Higher word
Return address to main
l (Lower word)
l (Higher word)
Low address
Stack pointer
Stack area
High address
Word
Return value
BC register
or
RP2 register BC register
Lower word
Processing
[FUNC function]
Saving register
(U)UP, RP3, (V)VP*
Storing return value
in BC or RP2, bc
Restoring registers
[Function main]
i
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NAME
FUNC2
EXTRN
_CSUB
PUBLIC
_FUNC2
CODE2
CSEG
_FUNC2:
movw
ax, #20H
;
6HW QG DUJXPHQW M
push
ax
;
movw
ax, #21H
;
6HW VW DUJXPHQW L
call
!_CSUB
;
&DOO &68% L M
pop
ax
ret
END
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Stack area
Low address
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CSUB(i, j)
1st argument
Word
BC register
Return value
16 bits or less
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RP2 register
Return value
17 bits or more
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extern void subf () ;
char
c = 0 ;
int
i = 0 ;
void main () {
subf () ;
}
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PUBLIC
_subf
EXTRN
_c
EXTRN
_I
@@CODE CSEG
_subf:
MOV
A, #04H
MOV
!!_c, A
MOVW
AX, #07H
MOVW
!!_i, AX
RET
END
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extern char c ;
extern int i ;
void subf ( )
{
c = `A' ;
i = 4 ;
}
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ASMSUB
PUBLIC
_c
PUBLIC
_i
ABC
CSEG
_c:
DB 0
_I:
DW 0
END
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extern int FUNC(int, long);
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void main ( ) {
int
i, j;
long
l;
i = 1;
l = 0x54321;
j = FUNC (i, l);
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}
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l (Lower word)
l (Higher word)
Low address
j = FUNC (i, I);
Stack area
High address
Stack pointer
AX register
i
User's Manual U15556EJ1V0UM
484
CHAPTER 13 EFFECTIVE UTILIZATION OF COMPILER
This chapter introduces how to effectively use this C compiler.
13.1 Efficient Coding
When developing 78K/IV Series microcontroller-applied products, efficient object generation may be realized with
this C compiler by utilizing the saddr1/2 area, callt table, or callf area of the device.
Use of external variables
if (saddr2 area can be used)
Use sreg/_ _sreg variables/use compiler option (-RD).
if (saddr1 area can be used)
Use _ _sreg1 variables.
Use of bit type (one bit) data
if (saddr2 area can be used)
Use bit/boolean/_ _boolean type variables.
if (saddr1 area can be used)
Use _ _boolean1 type variables.
Definition of function
if (the function is to be called frequently)
if (callt table can be used)
Declare it as _ _callt/callt function.
(Effective to shorten the code size)
if (callf area can be used)
Declare it as _ _callf/callf function.
(Effective to improve the execution speed)
CHAPTER 13 EFFECTIVE UTILIZATION OF COMPILER
User's Manual U15556EJ1V0UM
485
(1) Using external variables
When defining an external variable, specify the external variable to be defined as a sreg/_ _sreg variable if the
saddr2 area can be used. Instructions to sreg/_ _sreg variables are shorter in code length than instructions to
memory. This helps shorten object code and improve program execution speed. (The same can be also
performed by specifying the -RD option, instead of using the sreg variable.)
When saddr1 area as well as saddr2 area can be used, the similar effect can be achieved by specifying the
external variable to be defined as _ _sreg1 variable.
Definition of sreg/_ _sreg variable: extern sreg int variable-name ;
extern_ _sreg int
variable-name ;
Remark Refer to 11.5 (3) How to use the saddr area.
(2) 1-bit data
A data object which only uses 1-bit data should be declared as a bit type variable (or boolean/_ _boolean type
variable). A bit manipulation instruction will be generated for an operation on a bit/boolean/_ _boolean type
variable. Because saddr area is used as well as the sreg variable, the codes can be shortened and the
execution speed can be improved.
When saddr1 area as well as saddr2 area can be used, the similar effect can be achieved by specifying the
external variable to be defined as a _ _boolean1 type variable.
Declaration of bit/boolean type variable:
bit
variable-name ;
boolean
variable-name ;
_ _boolean
variable-name ;
Remark Refer to 11.5 (7) bit type variables.
CHAPTER 13 EFFECTIVE UTILIZATION OF COMPILER
User's Manual U15556EJ1V0UM
486
(3) Function definitions
For a function to be called over and over again, object code should be shortened or a structure which allows
calling at high speeds should be provided. If the callt table can be used for functions to be called frequently,
such functions should be defined as callt functions. Likewise, if the callf area can be used for functions to be
called frequently, such functions should be defined as callf functions. The callf functions can be called faster
than ordinary function calls with shorter codes because the callf functions are called using the callf area of the
device. The callt functions are effective when codes needs to be shortened because the callt functions use the
callt area of the device and are called with shorter code than callf.
Definition of callt function: callt int tsub() {
:
}
Definition of callf function: callf int tsub()
:
}
Remark Refer to 11.5 (1) callt function and 11.5 (15) callf function.
In addition to the use of the areas shown above, objects that do not need modification of the C source by
compiling with the optimization option can be generated. For the effect of each -Q suboption, refer to the
CC78K4 C Compiler Operation User's Manual (U15557E).
(4) Optimization option
The optimization options that emphasize the object code size the most is as follows.
[Object code is emphasized the most]
-QX3
Further shortening of the code size and improvement of the execution speed is possible by adding _ _sreg or _
_sreg1 to variables. However, this is restricted to the cases when saddr2 area or saddr1 area can be used.
When the areas have no more space and cannot be used, a compilation error occurs.
If execution speed is also highly emphasized, specify the -QX2 default.
If the code size is smaller than -QX3, -QX4 can be specified. However, there are restrictions during debugging.
CHAPTER 13 EFFECTIVE UTILIZATION OF COMPILER
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In addition, the object efficiency can be improved by adding the extended functions supported by this compiler to
the C source.
(5) Using extended functions
Definition of function
if (the function is to be called frequently)
if (the function is not to be used recursively)
Declare it as _ _leaf/norec functions.
if (the function does not use automatic variables)
Declare it as noauto function.
if (the function uses automatic variables and && register/saddr area can be used)
Declare it with register storage class.
if (use internal static variables) && (saddr2 area can be used)
Declare with _ _sreg/specify -RS option
Functions not used recursively
Of the functions to be called over and over again, the ones which are not used recursively should be defined
as _ _leaf/norec functions. norec functions become functions that do not have preprocessing/
postprocessing (stack frame). Therefore, the object code can be shortened and the execution speed can be
improved compared to the ordinary functions.
Remark
For the definition of the norec function (norec int rout ()...), refer to 11.5 (6) norec
function and 11.7.4 norec function call interface.
CHAPTER 13 EFFECTIVE UTILIZATION OF COMPILER
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Functions that do not use automatic variables
Functions that do not use automatic variables should be defined as noauto functions. These functions will
not output code for stack frame generation and their arguments will be passed to registers as much as
possible. These functions help shorten object code and improve program execution speed.
Remark For the definition of the noauto function (noauto int sub1 (int i)...), refer to 11.5 (5)
noauto functions and 11.7.3 noauto function call interface.
Functions that use automatic variables
If the saddr2 area can be used for a function that uses automatic variables, declare the function with the
register storage class specifier. By this register declaration, the object declared as register will be allocated
to a register. A program using registers operates faster than one using memory, and object code can be
shortened as well.
Remark For the definition of the register variable (register int i; ...), refer to 11.5 (2) Register
variables.
Functions that use internal static variables
If the saddr2 area can be used for a function that uses internal static variables, declare the function with
_ _sreg or specify the -RS option. In the same way as with sreg variables, the object code can be shortened
and the execution speed can be improved.
When saddr1 area can be used as well as saddr2 area, the same effect can be achieved by declaring the
function with _ _sreg1.
Remark
Refer to 11.5 (3) How to use saddr area.
CHAPTER 13 EFFECTIVE UTILIZATION OF COMPILER
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In addition, the code efficiency and the execution speed can be improved by the following methods.
Use of SFR name (or SFR bit name).
#pragma sfr
Use of _ _sreg/_ _sreg1 declaration for bit fields that consist only of 1-bit members (unsigned char type can
be used for members).
_ _sreg struct bf {
unsigned char
a:1;
unsigned char
b:1;
unsigned char
c:1;
unsigned char
d:1;
unsigned char
e:1;
unsigned char
f:1;
} bf_1;
Use of the register bank change for interrupt processing.
#pragma interrupt INTP0 inter RB1
Use of multiplication and division embedded function.
#pragma mul
#pragma div
Description of only the modules whose speed needs to be improved in the assembly language.
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APPENDIX A LIST OF LABELS FOR saddr AREA
With the CC78K4, addresses in the saddr2 area are referenced by the following label names. For this reason, the
same names as these label names cannot be used in the C source program or assembler source program.
For the areas of Section A.1 to A.3, any consecutive 32-byte area of saddr2 area (F) FD20H to (F) FDFFH is
used. The allocation addresses are determined at linking.
Remark
(F)FDXXH indicates the address where _@NRARG0 is allocated, and F is added to the higher 4 bits at
the location 1024K (0FH: Compiler option -CS15).
A.1 Arguments of norec Functions
Label Name
Address
_@NRARG0
(F)FDXXH
_@NRARG1
_@NRARG0 + 1H
_@NRARG2
_@NRARG0 + 2H
_@NRARG3
_@NRARG0 + 3H
_@NRARG4
_@NRARG0 + 4H
_@NRARG5
_@NRARG0 + 5H
_@NRARG6
_@NRARG0 + 6H
_@NRARG7
_@NRARG0 + 7H
APPENDIX A LIST OF LABELS FOR saddr AREA
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A.2 Automatic variables of norec Functions
Label Name
Address
_@NRAT00
_@NRARG0 + 8H
_@NRAT01
_@NRARG0 + 9H
_@NRAT02
_@NRARG0 + AH
_@NRAT03
_@NRARG0 + BH
_@NRAT04
_@NRARG0 + CH
_@NRAT05
_@NRARG0 + DH
_@NRAT06
_@NRARG0 + EH
_@NRAT07
_@NRARG0 + FH
A.3 Register Variables
Label Name
Address
_@KREG00
_@NRARG0 + 10H
_@KREG01
_@NRARG0 + 11H
_@KREG02
_@NRARG0 + 12H
_@KREG03
_@NRARG0 + 13H
_@KREG04
_@NRARG0 + 14H
_@KREG05
_@NRARG0 + 15H
_@KREG06
_@NRARG0 + 16H
_@KREG07
_@NRARG0 + 17H
_@KREG08
_@NRARG0 + 18H
_@KREG09
_@NRARG0 + 19H
_@KREG10
_@NRARG0 + 1AH
_@KREG11
_@NRARG0 + 1BH
_@KREG12
_@NRARG0 + 1CH
_@KREG13
_@NRARG0 + 1DH
_@KREG14
_@NRARG0 + 1EH
_@KREG15
_@NRARG0 + 1FH
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APPENDIX B LIST OF SEGMENT NAMES
This chapter explains all the segments that the compiler outputs and their locations.
(1) to (3) shows the options and re-allocation attributes used in the table.
(1) Option
-
-
-
-MS:
Small model
-
-
-
-MM:
Medium model
-
-
-
-ML:
Large model
-
-
-
-CS0:
Location 00H
-
-
-
-CS15:
Location 0FH
(2) Relocation attribute of CSEG
CALLT0:
Allocates the specified segment in the address 40H to 7FH with the start address
of a multiple of 2.
BASE:
Allocates the specified segment in the address 80H to 0FCFFH.
AT absolute expression:
Allocates the specified segment in an absolute address (within 0H to 0FCFFH,
10000H to 0FFFFFH)
Note
.
FIXED:
Allocates the start address of the specified segment in the address 800H to
0FFFH.
FIXEDA:
Allocates the start address of the specified segment in the address 800H to
0FFFH and the end within 0FCFFH.
PAGE:
Allocates the specified segment in the address xxx00H to xxxFFH (within
0FFFFFH).
PAGE64K:
Allocates the specified segment not to extend over the 64 KB boundary (within
0H to 0FCFFH, 10000H to 0FFFFFH)
Note
.
UNIT/without specification: Allocates the specified segment to a given location (within 80H to 0FCFFH,
10000H to 0FFFFFH)
Note
.
UNITP:
Allocates the specified segment to a given location with the start address in an
even address (80H to 0FCFFH, 10000H to 0FFFFFH)
Note
.
Note The range can be changed by specifying the
-
-
-
-CS option.
APPENDIX B LIST OF SEGMENT NAMES
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(3) Re-allocation attributes of DSEG
SADDR:
Allocates the specified segment to saddr1 area (saddr1 area: 0FE00H to
0FEFFH)
Note
SADDR2:
Allocates the specified segment to saddr2 area (saddr2 area: 0FD20H to
0FDFFH)
Note
SADDRP:
Allocates the specified segment starting from an even address in saddr1 area.
SADDRP2:
Allocates the specified segment starting from an even address in saddr2 area.
SADDRA:
Allocates the specified segment to a given area in saddr area (saddr area:
saddr1 area/saddr2 area).
AT absolute expression:
Allocates the specified segment to an absolute address.
UNIT/without specification:
Allocates the specified segment to a given location (within the memory area
name "RAM")
Note
.
UNITP:
Allocates the specified segment to a given location starting from an even
address (within the memory area name `RAM')
Note
.
PAGE:
Allocates the specified segment to a given location between XXXX00H to
XXXXFFH (within 0FFFFFH)
Note
.
PAGE64K:
Allocates the specified segment not to extend over the 64 KB boundary (within
0H to 0FCFFH, 10000H to FFFFFH)
Note
.
Note The range can be changed by specifying the
-
-
-
-CS option (the address may differ depending on the
target device. For details, refer to the user's manual of the target device used).
APPENDIX B LIST OF SEGMENT NAMES
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B.1 List of Segment Names
B.1.1 Program area and data area
(1) With small model (when
-
-
-
-MS is specified)
Section Name
Segment Type
Relocation Attribute
Description
@@BASE
CSEG
BASE
Segment for callt function and interrupt function
@@VECTnn
CSEG
AT nnH
Segment for interrupt vector table
@@CODES
CSEG
BASE
Segment for ordinary function codes
@@CNSTS
CSEG
BASE
Segment for const variables
@@CALFS
CSEG
FIXEDA
Segment for callf function
@@CALT
CSEG
CALLT0
Segment for table for callt function
@@RSINIT
CSEG
BASE
Segment for initialization data (with initial value)
@@RSINIS
CSEG
BASE
Segment for initialization data (sreg variable with initial value)
@@RSINS1
CSEG
BASE
Segment for initialization data (sreg1 variable with initial value)
@@INIT
DSEG
Segment for data area (with initial value)
@@DATA
DSEG
Segment for data area (without initial value)
@@INIS
DSEG
SADDR2
Segment for data area (sreg variable with initial value)
@@DATS
DSEG
SADDR2
Segment for data area (sreg variable without initial value)
@@INIS1
DSEG
SADDR
Segment for data area (sreg1 variable with initial value)
@@DATS1
DSEG
SADDR
Segment for data area (sreg1 variable without initial value)
@@BITS
BSEG
SADDR2
Segment for boolean type and bit type variables
@@BITS1
BSEG
SADDR
Segment for _ _boolean 1 type variable
@EXT00
CSEG
AT04080H
Segment for the flash area branch table (only when -ZF is
specified)
Note
Note When -ZF is specified, the second "@" from the top is changed to "E" in the section name. For details, refer
to B.1.2 Flash memory area (@@INIS
@EINIS, etc.).
Also, it is possible to change the address of the relocation attribute using #pragma ext_table.
Remark
For @@VECTnn, nn is determined when the interrupt source is specified by #pragma vect (interrupt)
(nn: Number of interrupt vector address).
APPENDIX B LIST OF SEGMENT NAMES
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(2) With large model (when
-
-
-
-ML is specified)
Section Name
Segment Type
Relocation Attribute
Description
@@BASE
CSEG
BASE
Segment for callt function and interrupt function
@@VECTnn
CSEG
AT nnH
Segment for interrupt vector table
@@CODE
CSEG
Segment for ordinary function codes
@@CNST
CSEG
Segment for const variables
@@CALF
CSEG
FIXED
Segment for callf function
@@CALT
CSEG
CALLT0
Segment for table for callt function
@@R_INIT
CSEG
Segment for initialization data (with initial value)
@@R_INIS
CSEG
Segment for initialization data (sreg variable with initial value)
@@R_INS1
CSEG
Segment for initialization data (sreg1 variable with initial
value)
@@INIT
DSEG
Segment for data area (with initial value)
@@DATA
DSEG
Segment for data area (without initial value)
@@INIS
DSEG
SADDR2
Segment for data area (sreg variable with initial value)
@@DATS
DSEG
SADDR2
Segment for data area (sreg variable without initial value)
@@INIS1
DSEG
SADDR
Segment for data area (sreg1 with initial value)
@@DATS1
DSEG
SADDR
Segment for data area (sreg1 variable without initial value)
@@BITS
BSEG
SADDR2
Segment for boolean type and bit type variables
@@BITS1
BSEG
SADDR
Segment for _ _boolean1 type variable
@EXT00
CSEG
AT04080H
Segment for the flash area branch table (only when -ZF is
specified)
Note
Note When -ZF is specified, the second "@" from the top is changed to "E" in the section name. For details, refer
to B.1.2 Flash memory area (@@INIS
@EINIS, etc.).
Also, it is possible to change the address of the relocation attribute using #pragma ext_table.
Remark
For the @@VECTnn, nn is determined when the interrupt source is specified by #pragma vect
(interrupt) (nn: Number of interrupt vector address).
APPENDIX B LIST OF SEGMENT NAMES
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(3) With medium model and location 00H (when
-
-
-
-MM and ----CS0 are specified)
Section Name
Segment Type
Relocation Attribute
Description
@@BASE
CSEG
BASE
Segment for callt function and interrupt function
@@VECTnn
CSEG
AT nnH
Segment for interrupt vector table
@@CODE
CSEG
Segment for ordinary function codes
@@CNSTS
CSEG
BASE
Segment for const variables
@@CALF
CSEG
FIXED
Segment for callf function
@@CALT
CSEG
CALLT0
Segment for table for callt function
@@R_INIT
CSEG
Segment for initialization data (with initial value)
@@R_INIS
CSEG
Segment for initialization data (sreg variable with initial value)
@@R_INS1
CSEG
Segment for initialization data (sreg1 variable with initial value)
@@INIT
DSEG
Segment for data area (with initial value)
@@DATA
DSEG
Segment for data area (without initial value)
@@INIS
DSEG
SADDR2
Segment for data area (sreg variable with initial value)
@@DATS
DSEG
SADDR2
Segment for data area (sreg variable without initial value)
@@INIS1
DSEG
SADDR
Segment for data area (sreg1 variable with initial value)
@@DATS1
DSEG
SADDR
Segment for data area (sreg1 variable without initial value)
@@BITS
BSEG
SADDR2
Segment for boolean type and bit type variables
@@BITS1
BSEG
SADDR
Segment for _ _boolean1 type variable
@EXT00
CSEG
AT04080H
Segment for the flash area branch table (only when -ZF is
specified)
Note
Note When -ZF is specified, the second "@" from the top is changed to "E" in the section name. For details, refer
to B.1.2 Flash memory area (@@INIS
@EINIS, etc.).
Also, it is possible to change the address of the relocation attribute using #pragma ext_table.
Remark
For the @@VECTnn, nn is determined when the interrupt source is specified by #pragma vect
(interrupt) (nn: Number of interrupt vector address).
APPENDIX B LIST OF SEGMENT NAMES
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(4) With medium model and location 0FH (when
-
-
-
-MM and ----CS15 are specified)
Section Name
Segment Type
Relocation Attribute
Description
@@BASE
CSEG
BASE
Segment for callt function and interrupt function
@@VECTnn
CSEG
AT nnH
Segment for interrupt vector table
@@CODE
CSEG
Segment for ordinary function codes
@@CNSTM
CSEG
PAGE64K
Segment for const variables
@@CALF
CSEG
FIXED
Segment for callf function
@@CALT
CSEG
CALLT0
Segment for table for callt function
@@R_INIT
CSEG
Segment for initialization data (with initial value)
@@R_INIS
CSEG
Segment for initialization data (sreg variable with initial value)
@@R_INS1
CSEG
Segment for initialization data (sreg1 variable with initial value)
@@INITM
DSEG
PAGE64K
Segment for data area (with initial value)
@@DATAM
DSEG
PAGE64K
Segment for data area (without initial value)
@@INIS
DSEG
SADDR2
Segment for data area (sreg variable with initial value)
@@DATS
DSEG
SADDR2
Segment for data area (sreg variable without initial value)
@@INIS1
DSEG
SADDR
Segment for data area (sreg1 variable with initial value)
@@DATS1
DSEG
SADDR
Segment for data area (sreg1 variable without initial value)
@@BITS
BSEG
SADDR2
Segment for boolean type and bit type variables
@@BITS1
BSEG
SADDR
Segment for _ _boolean1 type variable
@EXT00
CSEG
AT04080H
Segment for the flash area branch table (only when -ZF is
specified)
Note
Note When -ZF is specified, the second "@" from the top is changed to "E" in the section name. For details, refer
to B.1.2 Flash memory area (@@INIS
@EINIS, etc.).
Also, it is possible to change the address of the relocation attribute using #pragma ext_table.
Remark
For the @@VECTnn, nn is determined when the interrupt source is specified by #pragma vect
(interrupt) (nn: Number of interrupt vector address).
APPENDIX B LIST OF SEGMENT NAMES
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B.1.2 Flash memory area
(1) With small model (when
-
-
-
-MS is specified)
Section Name
Segment Type
Relocation Attribute
Description
@ECODES
CSEG
BASE
Segment for normal function codes
@ECNSTS
CSEG
BASE
Segment for const variables
@ERSINIT
CSEG
BASE
Segment for initialization data (with initial value)
@ERSINIS
CSEG
BASE
Segment for initialization data (sreg variable with initial value)
@ERSINS1
CSEG
BASE
Segment for initialization data (sreg1 variable with initial value)
@EINIT
DSEG
Segment for data area (with initial value)
@EDATA
DSEG
Segment for data area (without initial value)
@EINIS
DSEG
SADDR2
Segment for data area (sreg variable with initial value)
@EDATS
DSEG
SADDR2
Segment for data area (sreg variable without initial value)
@EINIS1
DSEG
SADDR
Segment for data area (sreg1 variable with initial value)
@EDATS1
DSEG
SADDR
Segment for data area (sreg1 variable without initial value)
@EBITS
BSEG
SADDR2
Segment for boolean type and bit type variables
@EBITS1
BSEG
SADDR
Segment for _ _boolean 1 type variable
(2) With large model (when
-
-
-
-ML is specified without 2-byte alignment)
Section Name
Segment Type
Relocation Attribute
Description
@ECODE
CSEG
Segment for normal function codes
@ECNST
CSEG
Segment for const variables
@ER_INIT
CSEG
Segment for initialization data (with initial value)
@ER_INIS
CSEG
Segment for initialization data (sreg variable with initial value)
@ER_INS1
CSEG
Segment for initialization data (sreg1 variable with initial value)
@EINIT
DSEG
Segment for data area (with initial value)
@EDATA
DSEG
Segment for data area (without initial value)
@EINIS
DSEG
SADDR2
Segment for data area (sreg variable with initial value)
@EDATS
DSEG
SADDR2
Segment for data area (sreg variable without initial value)
@EINIS1
DSEG
SADDR
Segment for data area (sreg1 with initial value)
@EDATS1
DSEG
SADDR
Segment for data area (sreg1 variable without initial value)
@EBITS
BSEG
SADDR2
Segment for boolean type and bit type variables
@EBITS1
BSEG
SADDR
Segment for _ _boolean1 type variable
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(3) With large model (when
-
-
-
-ML is specified with 2-byte alignment)
Section Name
Segment Type
Relocation Attribute
Description
@ECODE
CSEG
Segment for normal function codes
@ECNST
CSEG
UNITP
Segment for const variables
@ER_INIT
CSEG
UNITP
Segment for initialization data (with initial value)
@ER_INIS
CSEG
Segment for initialization data (sreg variable with initial value)
@ER_INS1
CSEG
Segment for initialization data (sreg1 variable with initial value)
@EINIT
DSEG
UNITP
Segment for data area (with initial value)
@EDATA
DSEG
UNITP
Segment for data area (without initial value)
@EINIS
DSEG
SADDR2
Segment for data area (sreg variable with initial value)
@EDATS
DSEG
SADDR2
Segment for data area (sreg variable without initial value)
@EINIS1
DSEG
SADDR
Segment for data area (sreg1 with initial value)
@EDATS1
DSEG
SADDR
Segment for data area (sreg1 variable without initial value)
@EBITS
BSEG
SADDR2
Segment for boolean type and bit type variables
@EBITS1
BSEG
SADDR
Segment for _ _boolean1 type variable
(4) With medium model and location 00H (when
-
-
-
-MM and ----CS0 are specified)
Section Name
Segment Type
Relocation Attribute
Description
@ECODE
CSEG
Segment for normal function codes
@ECNSTS
CSEG
BASE
Segment for const variables
@ER_INIT
CSEG
Segment for initialization data (with initial value)
@ER_INIS
CSEG
Segment for initialization data (sreg variable with initial value)
@ER_INS1
CSEG
Segment for initialization data (sreg1 variable with initial value)
@EINIT
DSEG
Segment for data area (variable with initial value)
@EDATA
DSEG
Segment for data area (without initial value)
@EINIS
DSEG
SADDR2
Segment for data area (sreg variable with initial value)
@EDATS
DSEG
SADDR2
Segment for data area (sreg variable without initial value)
@EINIS1
DSEG
SADDR
Segment for data area (sreg1 variable with initial value)
@EDATS1
DSEG
SADDR
Segment for data area (sreg1 variable without initial value)
@EBITS
BSEG
SADDR2
Segment for boolean type and bit type variables
@EBITS1
BSEG
SADDR
Segment for _ _boolean1 type variable
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(5) With medium model and location 0FH (when
-
-
-
-MM and ----CS15 are specified)
Section Name
Segment Type
Relocation Attribute
Description
@ECODE
CSEG
Segment for normal function codes
@ECNSTM
CSEG
PAGE64K
Segment for const variables
@ER_INIT
CSEG
Segment for initialization data (with initial value)
@ER_INIS
CSEG
Segment for initialization data (sreg variable with initial value)
@ER_INS1
CSEG
Segment for initialization data (sreg1 variable with initial value)
@EINITM
DSEG
PAGE64K
Segment for data area (with initial value)
@EDATAM
DSEG
PAGE64K
Segment for data area (without initial value)
@EINIS
DSEG
SADDR2
Segment for data area (sreg variable with initial value)
@EDATS
DSEG
SADDR2
Segment for data area (sreg variable without initial value)
@EINIS1
DSEG
SADDR
Segment for data area (sreg1 variable with initial value)
@EDATS1
DSEG
SADDR
Segment for data area (sreg1 variable without initial value)
@EBITS
BSEG
SADDR2
Segment for boolean type and bit type variables
@EBITS1
BSEG
SADDR
Segment for _ _boolean1 type variable
B.2 Location of Segment
Segment Type
Destination of Allocation (Default)
CSEG
ROM
BSEG
saddr area of RAM
DSEG
RAM
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B.3 Example of C Source
#pragma INTERRUPT INTP0 inter rb1
/* interrupt vector */
void inter(void);
/* interrupt function prototype declaration */
const int i_cnst = 1;
/* const variable */
callt void f_clt(void);
/* callt function prototype declaration */
callf void f_clf(void);
/* callf function prototype declaration */
boolean b_bit;
/* boolean type variable */
long l_init = 2;
/* external variable with initial value */
int i_data;
/* external variable without initial value */
sreg int sr_inis = 3;
/* sreg variable with initial value */
sreg int sr_dats;
/* sreg variable without initial value */
void main()
/* function definition */
{
int i;
i = 100;
}
void inter()
/* interrupt function definition */
{
unsigned char uc = 0;
uc++;
if(b_bit)
b_bit = 0;
}
callt void f_clt()
/* callt function definition */
{
}
callf void f_clf()
/* callf function definition */
{
}
APPENDIX B LIST OF SEGMENT NAMES
User's Manual U15556EJ1V0UM
502
B.4 Example of Output Assembler Module
Quasi-directives and instruction sets in an assembler source vary depending on the device.
Refer to the RA78K4 Online Help for details.
; 78K/IV Series C Compiler V2.30 Assembler Source
; Date:XX XXX XXXX Time:xx:xx:xx
; Command : -c4026 sample.c -sa -ng
; In-file : sample.c
; Asm-file : sample.asm
; Para-file :
$CHGSFR(15)
$PROCESSOR(4026)
$NODEBUG
$NODEBUGA
$KANJICODE SJIS
$TOL_INF 03FH, 0230H, 00H, 08021H, 00H
PUBLIC _inter
PUBLIC _i_cnst
PUBLIC ?f_clt
PUBLIC _f_clf
PUBLIC _b_bit
PUBLIC _l_init
PUBLIC _i_data
PUBLIC _sr_inis
PUBLIC _sr_dats
PUBLIC _main
PUBLIC _f_clt
PUBLIC _@vect06
@@BITS BSEG SADDR2
;
Segment for boolean type variable
_b_bit DBIT
@@CNST CSEG
;
Segment for const variable
_i_cnst: DW 01H ; 1
@@R_INIT CSEG
;
Segment for initialization data (external variable
DW 00002H,00000H ; 2
with initial value)
@@INIT DSEG
;
Segment for data area (external variable with initial
_l_init: DS (4)
value)
APPENDIX B LIST OF SEGMENT NAMES
User's Manual U15556EJ1V0UM
503
@@DATA DSEG
;
Segment for data area (external variable without
_i_data: DS (2)
initial value)
@@R_INIS CSEG
;
Segment for initialization data (sreg variable with
DW 03H ; 3
initial value)
@@INIS DSEG SADDR2
;
Segment for data area (sreg variable with initial
_sr_inis: DS (2)
value)
@@DATS DSEG SADDR2
;
Segment for data area (sreg variable without initial
_sr_dats: DS (2)
value)
@@CALT CSEG CALLT0
;
Segment for callt function
?f_clt: DW _f_clt
; line 1 : #pragma INTERRUPT INTP0 inter rb1
/* interrupt vector */
; line 2 :
; line 3 : void inter(void);
/* interrupt function prototype declaration */
; line 4 : const int i_cnst = 1;
/* const variable */
; line 5 : callt void f_clt(void);
/* callt function prototype declaration */
; line 6 : callf void f_clf(void);
/* callf function prototype declaration */
; line 7 : boolean b_bit;
/* boolean type variable */
; line 8 : long l_init = 2;
/* external variable with initial value */
; line 9 : int i_data;
/* external variable without initial value */
; line 10 : sreg int sr_inis = 3;
/* sreg variable with initial value */
; line 11 : sreg int sr_dats;
/* sreg variable without initial value */
; line 12 :
; line 13 : void main()
/* function definition */
; line 14 : {
@@CODE CSEG
;
Segment for code portion
_main:
push rp3
; line 15 : int i;
; line 16 : i = 100;
movw rp3,#064H ; 100
; line 17 : }
pop rp3
ret
; line 18 :
; line 19 : void inter()
/* interrupt function definition */
; line 20 : {
@@BASE CSEG BASE
;
Segment for callf/interrupt function
_inter:
sel RB1
APPENDIX B LIST OF SEGMENT NAMES
User's Manual U15556EJ1V0UM
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push rp3
; line 21 : unsigned char uc = 0;
mov r6,#00H ; 0
; line 22 : uc++;
inc r6
; line 23 : if(b_bit)
bf _b_bit,$L0005
; line 24 : b_bit = 0;
clr1 _b_bit
L0005:
; line 25 : }
pop rp3
reti
; line 26 :
; line 27 : callt void f_clt()
/* callt function definition */
; line 28 : {
_f_clt:
; line 29 : }
ret
; line 30 :
; line 31 : callf void f_clf()
/* callf function definition */
; line 32 : {
@@CALF CSEG FIXED
;
Segment for callf function
_f_clf:
; line 33 : }
ret
@@VECT06 CSEG AT 0006H
;
Segment for interrupt vector table
_@vect06:
DW _inter
END
; Target chip : uPD784026
; Device file : Vx.xx
User's Manual U15556EJ1V0UM
505
APPENDIX C LIST OF RUNTIME LIBRARIES
Table C-1 shows the runtime library list.
These operational instructions are called in the format where @@, etc. are attached at the beginning of the
function name.
However, cstart and cstarte are called in the format with _@ attached to the top.
All runtime libraries except hdwinit and boot_main are supported when the -ZF option is specified.
No library support is available for operations not in Table C-1. The compiler executes inline expansion.
long addition and subtraction, and/or/xor and shift may be expanded inline.
Table C-1. List of Runtime Libraries (1/5)
Classification
Function Name
Function
Increment
lsinc
Increments signed long.
luinc
Increments unsigned long.
finc
Increments float.
Decrement
lsdec
Decrements signed long.
ludec
Decrements unsigned long.
fdec
Decrements float.
Sign reverse
lsrev
Reverses the sign of signed long.
lurev
Reverses the sign of unsigned long.
frev
Reverses float.
Complement
lscom
Obtains one's complement of signed long.
lucom
Obtains one's complement of unsigned long.
NOT
lsnot
Negates signed long.
lunot
Negates unsigned long.
fnot
Negates float.
Multiply
lsmul
Performs multiplication between two signed long data.
lumul
Performs multiplication between two unsigned long data.
fmul
Performs multiplication between two float data.
Divide
csdiv
Performs division between two signed char data.
isdiv
Performs division between two signed int data.
lsdiv
Performs division between two signed long data.
ludiv
Performs division between two unsigned long data.
fdiv
Performs division between two float data.
Remainder
csrem
Obtains remainder after division between two signed char data.
isrem
Obtains remainder after division between two signed int data.
lsrem
Obtains remainder after division between two signed long data.
lurem
Obtains remainder after division between two unsigned long data.
APPENDIX C LIST OF RUNTIME LIBRARIES
User's Manual U15556EJ1V0UM
506
Table C-1. List of Runtime Libraries (2/5)
Classification
Function Name
Function
Add
lsadd
Performs addition between two signed long data.
luadd
Performs addition between two unsigned long data.
fadd
Performs addition between two float data.
Subtract
lssub
Performs subtraction between two signed long data.
lusub
Performs subtraction between two unsigned long data.
fsub
Performs subtraction between two float data.
Shift Left
lslsh
Shifts signed long to the left.
lulsh
Shifts unsigned long to the left.
Shift Right
lsrsh
Shifts signed long to the right.
lursh
Shifts unsigned long to the right.
Compare
lscmp
Compares two signed long data.
lucmp
Compares two unsigned long data.
fcmp
Compares two float data.
Bitwise AND
lsband
Performs bitwise AND operation between two signed long data.
luband
Performs bitwise AND operation between two unsigned long data.
Bitwise OR
lsbor
Performs bitwise OR operation between two signed long data.
lubor
Performs bitwise OR operation between two unsigned long data.
Bitwise XOR
lsbxor
Performs bitwise XOR operation between two signed long data.
lubxor
Performs bitwise XOR operation between two unsigned long data.
Logical AND
fand
Performs logical AND operation between two float data.
Logical OR
for
Performs logical OR operation between two float data.
ftols
Converts from float to signed long.
ftolu
Converts from float to unsigned long.
lstof
Converts from signed long to float.
lutof
Converts from unsigned long to float.
Type
conversion
from bit
btol
Converts bit to long.
Preprocess/
postprocess
hdwinit
Initializes peripheral units (sfr) immediately after CPU has been reset.
Conversion from
floating point
number
Conversion to
floating point
number
APPENDIX C LIST OF RUNTIME LIBRARIES
User's Manual U15556EJ1V0UM
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Table C-1. List of Runtime Libraries (3/5)
Classification
Function Name
Function
Startup routine
cstart
Startup module (including the startup module for booting)
In the case of a startup module for booting,
library.inc, in which a library name EXTERN declaration is described in the
comments is included.
If the library name's EXTERN declaration comment is removed, it is used
in the flash area.
The library can be used in the boot area.
EXTERN declarations _@vect00 to @vect3e are executed and are located
in the flash area.
Set an interrupt vector table for interrupt functions.
Secure an area (2 x 32 bytes, 3 x 32 bytes for the medium model and large
model) to register functions by the atexit function, and let the top label
name be _@FNCTBL.
Secure a break area (32 bytes, 64 bytes in the large model) and let the top
label name be _@MEMTOP, then let the area's next address label name
be _@MEMBTM.
Define the reset vector table's segment as follows and specify the top
address of the startup module.
@@VECT00 CSEG AT 0000H
DW
_@cstart
Specify LOCATION.
Set the V, U, T and W registers to 0 (small model only).
Set the V, U, T and W registers to 0 (LOCATION 0) and 0FH (LOCATION
15) (medium model only).
Set the register bank to RB0.
Set variable _errno input in the error No to 0.
Set the variable _@FNCENT which inputs the number of functions
registered by the atexit function to.
Set the address of _@MEMTOP in variable _@BRAKADR as the initial
break value.
Set 1 as the initial value in the variable _@SEED which is the source of
pseudo random numbers for the rand function.
Execute 0 clearing of data from initialization data copy processing and
external data without initialization values.
APPENDIX C LIST OF RUNTIME LIBRARIES
User's Manual U15556EJ1V0UM
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Table C-1. List of Runtime Libraries (4/5)
Classification
Function Name
Function
Startup routine
cstart
Startup module (including startup modules for booting)
In the case of a startup module for booting (for flash)
Call the boot_main function (user program).
Branch to the flash area's branch table top (ITBLTOP) and move
processing to the startup module for flash memory.
Declare the following labels and variables (distinguish between upper case
and lower case letters).
The user is prohibited to define these symbols.
_@FNCTBL
(3 bytes: Medium model, large model)
_@MEMTOP
(3 bytes: Large model)
_@MEMBTM
(3 bytes: Large model)
_errno
(2 bytes)
_@FNCENT
(2 bytes)
_@BRKADR
(2 bytes/3 bytes: Large model)
_@SEED
(4 bytes) _@DIVR (4 bytes)
_@LDIVR
(8 bytes)
_@TOKPRT
(2 bytes/3 bytes: Large model)
In the case of a startup module for booting
Call the main function (user program).
Call the exit function by parameter 0.
cstarte
Startup module for flash memory
Define the flash area branch table for branching to the startup module for
flash memory (ITBLTOP is the top address for the flash area branch table).
@EVECT00 CSEG AT ITBLTOP
BR
_@cstarte
Set the final address of the stack area + 1 in the stack pointer (SP).
Execute 0 clearing of data from initialization data copy processing and
external data without initialization values.
Call the main function.
Call the exit function by parameter 0.
Flash
compatibility
boot_main
Execute boot area main function processing (function prototype: void
boot_main (void);). This function returns without doing anything. However,
as necessary, the user, by creating it, can execute processing which suit's
the user's purpose.
Example: In cases where update processing of the flash area program is
executed by referring to SFR, etc.
vect00 to 3e
Create an interrupt vector table when the -ZF option is specified
(function prototype: void vect00(void);, ..., void vect3e (void)).
Specify the top address value of the interrupt function located in the flash
area in the interrupt vector table.
APPENDIX C LIST OF RUNTIME LIBRARIES
User's Manual U15556EJ1V0UM
509
Table C-1. List of Runtime Libraries (5/5)
Classification
Function Name
Function
addwc
anda0
aX3de
aX3whl
aXxwhl
clrhw
cmpa0
cmpax0
cmpaxf
cmpbc0
cmpbcf
eX2de
eX4de
mova0
movax1
movaxs
movbcf
movdes
movs0
movsax
muluwt
muluww
mulwde
mulwhl
sladd
slsdiv
slsmul
slsrem
slsub
sludiv
slumul
slurem
For replacing the fixed-type instruction pattern
Auxiliary
swtbla
Converts switch branch table to 2-byte table.
User's Manual U15556EJ1V0UM
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APPENDIX D LIST OF LIBRARY STACK CONSUMPTION
Table D-1 shows the number of stacks consumed from the standard libraries.
Table D-1. List of Standard Library Stack Consumption (1/4)
Classification
Function Name
Small Model
Medium Model
Large Model
isalnum
0
0
0
salpha
0
0
0
iscntrl
0
0
0
isdigit
0
0
0
isgraph
0
0
0
islower
0
0
0
isprint
0
0
0
ispunct
0
0
0
isspace
0
0
0
isupper
0
0
0
isxdigit
0
0
0
tolower
0
0
0
toupper
0
0
0
isascii
0
0
0
toascii
0
0
0
_tolower
0
0
0
_toupper
0
0
0
tolow
0
0
0
ctype.h
toup
0
0
0
setjmp
6
6
0
setjmp.h
longjmp
0
0
0
va_arg
0
0
0
va_start
0
0
0
stdarg.h
va_end
0
0
0
sprintf
56 (115)
56 (116)
55 (119)
Note
sscanf
293 (334)
293 (335)
293 (341)
Note
printf
65 (116)
67 (118)
71 (121)
Note
scanf
304 (336)
308 (338)
308 (344)
Note
vprintf
65 (116)
67 (118)
71 (121)
Note
vsprintf
56 (115)
56 (116)
55 (119)
Note
getchar
0
0
0
gets
7
7
9
putchar
0
0
0
stdio.h
puts
5
5
6
Note Values in parentheses are for when the version that supports floating-point numbers is used.
APPENDIX D LIST OF LIBRARY STACK CONSUMPTION
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Table D-1. List of Standard Library Stack Consumption (2/4)
Classification
Function Name
Small Model
Medium Model
Large Model
atoi
11
11
1
atol
11
11
1
strtol
14
17
21
strtoul
14
17
21
calloc
11
11
18
free
9
9
12
malloc
9
9
12
realloc
14
14
20
abort
0
0
0
atexit
0
0
3
exit
n+3
n+3
n+3
Note 1
abs
0
0
0
div
6
6
6
labs
0
0
0
ldiv
8
8
11
brk
3
3
6
sbrk
3
3
6
atof
39
39
40
strtod
39
39
40
itoa
6
6
8
ltoa
10
10
12
ultoa
10
10
11
rand
5
5
5
srand
0
0
0
bsearch
25+n
26+n
29+n
Note 2
qsort
36+n
43+n
44+n
Note 3
strbrk
3
3
6
strsbrk
3
3
6
stritoa
6
6
8
strltoa
10
10
13
stdlib.h
strultoa
10
10
11
Notes 1. n is the total stack consumption among external functions registered by the atexit function.
2. n is the stack consumption of external functions called from bsearch.
3. n is (20 + stack consumption of external functions called from qsort)
(1 + number of times recursive
calls occurred).
APPENDIX D LIST OF LIBRARY STACK CONSUMPTION
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Table D-1. List of Standard Library Stack Consumption (3/4)
Classification
Function Name
Small Model
Medium Model
Large Model
memcpy
0
0
3
memmove
0
0
6
strcpy
0
0
3
strncpy
0
0
3
strcat
0
0
3
strncat
0
0
3
memcmp
0
0
0
strcmp
0
0
0
strncmp
0
0
0
memchr
0
0
0
strchr
0
0
0
strcspn
0
0
3
strpbrk
0
0
3
strrchr
0
0
0
strspn
0
0
3
strstr
2
2
3
strtok
0
0
6
memset
0
0
0
strerror
3
6
6
strlen
0
0
0
strcoll
0
0
0
string.h
strxfrm
2
2
3
acos
31
31
31
asin
31
31
31
atan
28
28
28
atan2
28
28
28
cos
26
26
26
sin
26
26
26
tan
33
33
33
cosh
31
31
31
sinh
31
31
31
tanh
37
37
37
exp
28
28
28
frexp
0 (14)
0 (14)
0 (15)
Note
ldexp
0 (11)
0 (11)
0 (12)
Note
log
30
30
30
log10
30
30
30
math.h
modf
7 (11)
7 (11)
7 (12)
Note
Note Values in parentheses are for when an operation exception occurs.
APPENDIX D LIST OF LIBRARY STACK CONSUMPTION
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Table D-1. List of Standard Library Stack Consumption (4/4)
Classification
Function Name
Small Model
Medium Model
Large Model
pow
30
30
30
sqrt
12
12
12
ceil
7 (11)
7 (11)
7 (12)
Note 1
fabs
0
0
0
floor
7 (11)
7 (11)
7 (12)
Note 1
fmod
6 (11)
6 (11)
6 (12)
Note 1
matherr
0
0
0
asinf
31
31
31
atanf
28
28
28
atan2f
28
28
28
cosf
26
26
26
sinf
26
26
26
tanf
33
33
33
coshf
31
31
31
sinhf
31
31
31
tanhf
37
37
37
expf
28
28
28
rexpf
0 (14)
0 (14)
0 (15)
Note 1
ldexpf
0 (11)
0 (11)
0 (12)
Note 1
logf
30
30
30
log10f
30
30
30
modff
7 (11)
7 (11)
7 (12)
Note 1
powf
30
30
30
sqrtf
12
12
12
ceilf
7 (11)
7 (11)
7 (12)
Note 1
fabsf
0
0
0
floorf
7 (11)
7 (11)
7 (12)
Note 1
math.h
fmodf
6 (11)
6 (11)
6 (12)
Note 1
assert.h
_ _assertfail
76 (127)
78 (129)
85 (135)
Note 2
Notes 1. Values in parentheses are for when an operation exception occurs.
2. Values in parentheses are for when the printf version that supports floating-point numbers is used.
APPENDIX D LIST OF LIBRARY STACK CONSUMPTION
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Table D-2 shows the number of stacks consumed from the runtime libraries.
Table D-2. List of Runtime Library Stack Consumption (1/3)
Classification
Function Name
Small Model
Medium Model
Large Model
lsinc
0
0
0
luinc
0
0
0
Increment
finc
15 (24)
15 (24)
16 (26)
Note
lsdec
0
0
0
ludec
0
0
0
Decrement
fdec
15 (24)
15 (24)
16 (26)
Note
lsrev
2
2
2
lurev
2
2
2
Sign reverse
frev
0
0
0
lscom
0
0
0
1's complement
lucom
0
0
0
lsnot
0
0
0
lunot
0
0
0
Logical NOT
fnot
0
0
0
lsmul
2
2
2
lumul
2
2
2
Multiply
fmul
8 (17)
8 (17)
9 (19)
Note
csdiv
4
4
4
isdiv
6
6
6
lsdiv
13
13
13
ludiv
6
6
6
Divide
fdiv
8 (17)
8 (17)
9 (19)
Note
csrem
4
4
4
isrem
6
6
6
lsrem
13
13
13
Remainder
lurem
6
6
6
lsadd
0
0
0
luadd
0
0
0
Add
fadd
8 (17)
8 (17)
9 (19)
Note
lssub
0
0
0
lusub
0
0
0
Subtract
fsub
8 (17)
8 (17)
9 (19)
Note
Note Values in parentheses are for when an operation exception occurs (when the matherr function included
with the compiler is used).
APPENDIX D LIST OF LIBRARY STACK CONSUMPTION
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Table D-2. List of Runtime Library Stack Consumption (2/3)
Classification
Function Name
Small Model
Medium Model
Large Model
lslsh
0
0
0
Shift left
lulsh
0
0
0
lsrsh
0
0
0
Shift right
lursh
0
0
0
lscmp
0
0
0
lucmp
0
0
0
Compare
fcmp
2 (17)
2 (17)
2 (19)
Note
lsband
0
0
0
Bit AND
luband
0
0
0
lsbor
0
0
0
Bit OR
lubor
0
0
0
lsbxor
0
0
0
Bit XOR
lubxor
0
0
0
Logical AND
fand
0
0
0
Logical OR
for
0
0
0
ftols
2
2
2
Conversion from
floating-point number
ftolu
2
2
2
lstof
2
2
2
Conversion to
floating-point number
lutof
2
2
2
Conversion from bit
btol
2
2
2
Startup routine
cstart
3
3
3
Note Values in parentheses are for when an operation exception occurs (when the matherr function included
with the compiler is used).
APPENDIX D LIST OF LIBRARY STACK CONSUMPTION
User's Manual U15556EJ1V0UM
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Table D-2. List of Runtime Library Stack Consumption (3/3)
Classification
Function Name
Small Model
Medium Model
Large Model
addwc
0
5
5
anda0
0
0
0
aX3de
0
0
0
aX3whl
0
0
0
aXxwhl
0
0
0
clrhw
0
0
0
cmpa0
0
0
0
cmpax0
0
0
0
cmpaxf
0
0
0
cmpbc0
0
0
0
cmpbcf
0
0
0
eX2de
0
0
0
eX4de
0
0
0
mova0
0
0
0
movax1
0
0
0
movaxs
2
3
5
movbcf
0
0
0
movdes
4
5
5
movs0
4
7
5
movsax
4
7
5
muluwt
0
muluww
0
mulwde
0
mulwhl
0
sladd
3
3
3
Note
slsdiv
3
3
3
Note
slsmul
9
9
9
Note
slsrem
25
25
25
Note
slsub
5
5
5
Note
sludiv
9
9
9
Note
slumul
9
9
9
Note
slurem
13
11
11
Note
Auxiliary
swtbla
0
Note
Note Stack correction for the 4 bytes used for placing an argument when a function is called is performed on the
side of called function.
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APPENDIX E INDEX
\a...............................................................................35
\b...............................................................................35
\f................................................................................35
\n...............................................................................35
\r................................................................................35
\t................................................................................35
\v ...............................................................................39
#asm - #endasm .....................................................336
#define directive......................................................150
#include ....................................................................50
#include directive ............................144, 145, 146, 147
#operator ................................................................148
##operator ..............................................................148
#pragma directive ...........................................155, 289
#undef directive ......................................................152
_ _ assertfail ...........................................................278
_ _asm ....................................................................336
_ _boolean ..................................................28, 29, 326
_ _boolean type variables...........................28, 29, 326
_ _boolean1 type variable...........................28, 29, 331
_ _callf ....................................................................356
_ _callt.....................................................................292
_ _DATA_ _ ............................................................156
_ _FILE_ _ ..............................................................156
_ _interrupt..............................................................346
_ _interrupt_brk.......................................................346
_ _LINE_ _..............................................................156
_ _OPC ...................................................................400
_ _pascal_ _ ...............................................29, 31, 421
_ _rtos_interrupt qualifier ........................................408
_ _STDC_ _ ............................................................156
_ _TIME_ _ .............................................................156
_toupper..................................................................174
-QH option ..............................................................414
-ZF option ...............................................................425
-ZO option...............................................................413
-ZR option ...............................................................424
??..............................................................................35
A
abort........................................................................203
abs ..........................................................................205
absolute address access function ..............28, 30, 363
acos ........................................................................233
acosf .......................................................................256
aggregate type ......................................................... 45
allocation function .................................... 30, 287, 361
ANSI ....................................................................... 283
arithmetic operators ................................................. 85
arrays ..................................................................... 128
array type ................................................................. 45
array declarators ...................................................... 59
asin......................................................................... 234
asinf........................................................................ 257
ASM statements ......................................... 28, 29, 336
Assembly language .................................................. 19
assignment operators............................................. 101
atan ........................................................................ 235
atan2 ...................................................................... 236
atan2f ..................................................................... 259
atanf ....................................................................... 258
atexit....................................................................... 204
atof ......................................................................... 208
atoi ......................................................................... 194
atol ......................................................................... 194
auto .......................................................................... 52
B
binary constant................................................. 30, 389
bit field...................................................... 56, 127, 367
bit field declaration ..................................... 28, 30, 367
bit type variables ........................................ 28, 29, 326
bitwise AND operators.............................................. 94
bitwise inclusive OR operators ................................. 96
bitwise XOR operators ............................................. 95
block scope .............................................................. 38
boolean type variables ............................... 28, 29, 326
boolean1 type variables ............................. 28, 29, 326
branch statements.................................................. 120
break statements.................................................... 123
brk .......................................................................... 207
BRK ........................................................................ 352
bsearch .................................................................. 212
C
C language ............................................................... 19
callf/_ _callf function................................................. 28
callf function ............................................... 28, 29, 356
calloc ...................................................................... 199
APPENDIX E INDEX
User's Manual U15556EJ1V0UM
518
callt function ..................................................... 28, 292
cast operators .......................................................... 84
ceil.......................................................................... 251
ceilf......................................................................... 274
changing compiler output section name ................ 375
changing function call interface........................ 31, 413
char type .................................................................. 40
character constant ................................................... 48
character type .......................................................... 44
comma operator ..................................................... 104
comment .................................................................. 50
compatible type........................................................ 46
composite type......................................................... 46
compound assignment operators........................... 103
compound statement ............................................. 112
conditional operators.............................................. 100
conditional control statements ............................... 113
const ........................................................................ 58
constants.................................................................. 46
constant expressions ............................................. 105
continue statement................................................. 122
cos ......................................................................... 237
cosf ........................................................................ 260
cosh ....................................................................... 240
coshf ...................................................................... 263
CPU control instruction .................................... 30, 352
D
data insertion function................................ 28, 31, 400
decimal constant ...................................................... 47
delimiters.................................................................. 49
DI ........................................................................... 349
div .......................................................................... 206
device type............................................................. 156
division function ......................................... 28, 30, 398
do statement .......................................................... 118
E
EI ........................................................................... 349
enumeration constant .............................................. 48
enumeration specifiers............................................. 56
enumeration type ..................................................... 41
equality operators .................................................... 91
escape sequence..................................................... 35
exit ......................................................................... 204
exp ......................................................................... 243
expf ........................................................................ 266
expression statements ...........................................112
ext_tsk ....................................................................410
extern ...............................................................52, 134
external object definitions.......................................136
external linkage ........................................................39
external definitions .................................................133
F
fabs.........................................................................252
fabsf........................................................................275
file scope ..................................................................38
firmware ROM function ...........................................433
flash area branch table ...........................................426
floating point constant ..............................................47
floating point type .....................................................41
floor ........................................................................253
floorf .......................................................................276
fmod........................................................................254
fmodf.......................................................................277
for statement...........................................................119
free .........................................................................200
frexp .......................................................................244
frexpf ......................................................................267
function .....................................................................23
function call function from the boot area ................430
function declarators ..................................................60
function definition ...................................................134
function prototype scope ..........................................38
function scope ..........................................................38
function to change compiler output section name ....30
function type .............................................................45
G
general integral promotion........................................67
getchar ...................................................................190
gets.........................................................................191
goto statement........................................................121
H
HALT ......................................................................352
header file...............................................................163
header name ............................................................50
hexadecimal constant...............................................47
I
identifiers ..................................................................37
APPENDIX E INDEX
User's Manual U15556EJ1V0UM
519
if...else statement....................................................114
incomplete type.........................................................45
integer type ...............................................................67
integral type ..............................................................41
internal linkage..........................................................39
interrupt function qualifier .......................................347
interrupt functions .............................................29, 340
interrupt handler for RTOS ...............................31, 402
interrupt handler qualifier for RTOS ..................31, 408
isalnum ...................................................................171
isalpha ....................................................................171
isascii ......................................................................171
iscntrl ......................................................................171
isdigit.......................................................................171
isgraph ....................................................................171
islower.....................................................................171
isprint ......................................................................171
ispunct ....................................................................171
isspace....................................................................171
isupper ....................................................................171
isxdigit.....................................................................171
iteration statement ..................................................116
itoa ..........................................................................210
K
key words..................................................................36
L
labeled statements..................................................109
labs .........................................................................205
ldexp .......................................................................245
ldexpf ......................................................................268
ldiv ..........................................................................206
log ...........................................................................246
log10 .......................................................................247
log10f ......................................................................270
logf ..........................................................................269
logical AND operators...............................................98
logical OR operators .................................................99
longjmp ...................................................................175
ltoa ..........................................................................210
M
machine language ....................................................19
macro name ............................................................156
macro replacement directives.................................150
malloc .....................................................................201
matherr ................................................................... 255
memchr .................................................................. 222
memcmp................................................................. 220
memcpy.................................................................. 217
memmove............................................................... 217
memset................................................................... 228
medium model................................................ 287, 358
modf ....................................................................... 248
modff ...................................................................... 271
module name changing function ...................... 30, 391
multiplication function................................. 28, 30, 395
N
noauto functions......................................... 28, 29, 312
no linkage................................................................. 39
NOP........................................................................ 352
norec functions........................................... 28, 29, 318
O
octal constant ........................................................... 47
P
pascal function ................................................. 31, 421
pascal function call interface .................................. 424
peekb ..................................................................... 363
peekw..................................................................... 363
pintf ........................................................................ 186
pointer ...................................................................... 69
pointer declarator ..................................................... 59
pokeb ..................................................................... 363
pokew..................................................................... 363
postfix operators....................................................... 73
pow......................................................................... 249
powf........................................................................ 272
preprocessing directives ........................................ 137
putchar ................................................................... 192
puts ........................................................................ 193
Q
qsort ....................................................................... 213
R
rand ........................................................................ 211
realloc..................................................................... 202
re-entrantability ...................................................... 169
register ..................................................................... 52
APPENDIX E INDEX
User's Manual U15556EJ1V0UM
520
register bank .......................................................... 287
register bank specification ..................................... 341
register variables...................................................... 28
relational operators .................................................. 90
return statement ..................................................... 124
rolb ......................................................................... 392
rolw ........................................................................ 392
ROMization-related section name.......................... 383
rorb......................................................................... 392
rorw ........................................................................ 392
rotate function ............................................ 28, 30, 392
RTOS ..................................................................... 283
S
scalar type............................................................... 45
sbrk ........................................................................ 207
scanf ...................................................................... 187
setjmp .................................................................... 175
sfr area..................................................................... 29
sfr variable ............................................................. 309
shift operators .......................................................... 88
signed integral type.................................................. 41
simple assignment operators ................................. 102
sin .......................................................................... 238
sinf ......................................................................... 261
sinh ........................................................................ 241
sinhf ....................................................................... 264
small model .................................................... 287, 358
sprintf ..................................................................... 178
sqrt ......................................................................... 250
sqrtf ........................................................................ 273
srand ...................................................................... 211
sreg declaration ..................................................... 301
sreg variable .................................................... 28, 301
sreg1 variable ........................................................ 306
sscanf..................................................................... 182
stack change specification ..................................... 342
startup routine ........................................................ 384
static................................................................. 52, 134
STOP ..................................................................... 352
storage class specifiers............................................ 52
strbrk ...................................................................... 214
strcat ...................................................................... 219
strchr ...................................................................... 223
strcmp .................................................................... 221
strcoll...................................................................... 231
strcpy ..................................................................... 218
strcspn ................................................................... 224
strerror ....................................................................229
string literals .............................................................49
stritoa......................................................................216
strlen.......................................................................230
strltoa......................................................................216
strncat.....................................................................219
strncmp...................................................................221
strncpy ....................................................................218
strpbrk ....................................................................225
strrchr .....................................................................223
strsbrk.....................................................................215
strspn......................................................................224
strstr .......................................................................226
strtod ......................................................................208
strtol........................................................................227
strtoul......................................................................196
struct.......................................................................126
structures................................................................126
structure pointer .....................................................126
structure specifier .....................................................55
structure type............................................................45
structure variable ....................................................126
strultoa....................................................................216
strxfrm.....................................................................232
switch statement.....................................................115
T
tags...........................................................................57
tan ..........................................................................239
tanf .........................................................................262
tanh ........................................................................242
tanhf .......................................................................265
task .........................................................................410
task function for RTOS .....................................31, 410
toascii .....................................................................173
tolow .......................................................................174
tolower ....................................................................172
toup ........................................................................174
toupper ...................................................................172
trigraph sequences ...................................................35
type conversions ......................................................65
type names ...............................................................60
type qualifiers ...........................................................58
typedef......................................................................52
U
ultoa........................................................................210
APPENDIX E INDEX
User's Manual U15556EJ1V0UM
521
unary operators.........................................................79
union .......................................................................130
union specifier...........................................................55
union type .................................................................45
unsigned integral type...............................................41
usage of saddr area................................................301
V
va_arg.....................................................................176
va_end ....................................................................176
va_start ...................................................................176
va_starttop ..............................................................176
void ...........................................................................69
void pointer ...............................................................69
volatile.......................................................................58
vprintf ......................................................................188
vsprintf ....................................................................189
W
while statement.......................................................117
522
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