Program Listing, 136 | HP UX Developer Tools instruction

Programming Examples

4. Demonstrating the Procedure Calling Convention

4.Demonstrating the Procedure Calling Convention

A C program calls an assembly language program to test if .ENTER and

.LEAVE are working correctly. The assembly language program checks to see if the C program has passed the value zero in arg0. The assembly language program then returns the value -9in ret0 to the calling program.

You need to compile this assembly listing using cc. The registers ret0 and arg0 are declared within /usr/lib/pcc_prefix.s, which is automatically included when you give the C compiler an assembly ﬁle.

To remove the dependency on pcc_prefix.s, replace all occurrences of ret0 with %r28 and arg0 with %r26.

C Program Listing

#include <stdio.h> int errorcount = 0; main ()

{

int toterr = 0;

printf("TESTING FEATURE 000");

fflush(stdout);
if( feat000(000)	!=	-9 ) ++errorcount;
printf("	%d	errors\\n",errorcount);

toterr += errorcount; errorcount = 0;

}

136

Chapter 7

Image 136

HP UX Developer Tools manual Demonstrating the Procedure Calling Convention, Program Listing, 136

Contents

HP 9000 Computers 92432-90012 June Restricted Rights Legend Legal NoticesHanover Street Palo Alto, California Contents Assembler Directives and Pseudo-Operations Contents Contents Contents Contents Pseudo-Instruction Set Assembling Your Program Programming Examples Diagnostic MessagesIndex Printing History PrefaceEdition Date Software Version Audience Related Documentation Typographical Conventions This Manual Summary of Technical Changes for HP-UX Assembly Language Assembler Features Assembler Features Summary of Changes for PA-RISC Summary of Changes for PA-RISC 2.0W Wide Mode, 64-bitSummary of Changes for PA-RISC Chapter Summary of Changes for PA-RISC 2.0W Wide Mode, 64-bit Program Structure Program Structure Label Opcode Operands Comments Symbols and Constants Symbols and Constants Integer Constants Signed Unsigned Registers and Register Mnemonics Registers and Register Mnemonics Registers by using an L or R sufﬁx General Registers Single-Precision Floating-Point Registers Space Registers Double-Precision Floating-Point RegistersControl Registers Synonyms Register Procedure Calling Conventions Register Synonyms Description Expressions ExpressionsStandard Arithmetic Operators Operator Operation Legal Combinations For Relocatable Terms Operation Result Available Field Selectors Meaning Field Meaning Selector Multiple of 2048 allows a three-instruction sequence Parenthesized Subexpressions Operands and Completers Operands and Completers Addi Deﬁning New Instructions With Macros Macro ProcessingMacro Processing Contains general register 19, or binary 10011. These HP-UX Architecture Conventions Spaces Spaces Memory Layout on HP-UX Sr4 Sr5 Sr6 Attributes SubspacesSubspaces Standard Subspaces and Sort Keys DirectivesSpace Subspace Sort Key Use Sections in 64-bit Mode Sections in 64-bit Mode $INIT$ Location Counters Location Counters Compiler Conventions Compiler Conventions Compiler Conventions Global Symbol Usage Mfctl Shared Libraries Assembly ListingShared Libraries Assembly Listing Assembler Directives IntroductionDirective Function Requests common storage for a speciﬁed number Bytes Pseudo-Operations Directive Function Reserves 16 bits a half word of storage Align Directive SyntaxParameters Example Discussion Allow DirectiveAllow Directive To the .LEVEL speciﬁed for the ﬁle Block and .BLOCKZ Pseudo-Operations Block and .BLOCKZ Pseudo-Operations Space $TEXT$ Subspa $CODE$ Block Byte Pseudo-Operation Byte Pseudo-OperationByte initvalue , initvalue Call Directive Call DirectiveCall argumentdescription argumentdescription Form of argument-description is Arg=location Where arg can Return value for a procedureﬁrst word in the argument list Second word in the argument list LIT Align Word Procend Export Callinfo Directive Callinfo DirectiveCallinfo parameter , parameter Register ENTRYSR= Unwound It restores the RP value when it encounters a .LEAVE Callinfo Directive Stack Frames Re-enter code subspace Comm Directive Comm DirectiveLabel .COMM numbytes Label Labels the location of the reserved storage Copyright Directive Copyright DirectiveCompany-name Proc Callinfo Enter Integer .fraction E power Fraction E powerDouble Pseudo-Operation Double Pseudo-Operation Dword Pseudo-Operation Dword Pseudo-OperationDword initvalue , initvalue END Directive END Directive Endm Directive Endm Directive Enter and .LEAVE Pseudo-Operations Enter and .LEAVE Pseudo-Operations Space $TEXT$ Entry and .EXIT Directives Entry and .EXIT Directives Symbolicname .EQU value EQU DirectiveEQU Directive Value Export Directive Export Directive Argument Export proc,ENTRY,ARGW0=GR Float Pseudo-Operation Float Pseudo-Operation Half Pseudo-Operation Half Pseudo-OperationHalf initvalue , initvalue Import Directive Import Directive NOP END Label Directive Label DirectiveLabel labelid Labelid Names the label identiﬁer Level Directive Level Directive Level Directive Listoff and .LISTON Directives Listoff and .LISTON Directives Liston Code Space $TEXT$ SPNUM=0,SORT=0 Subspa $CODE$ Locct Directive Locct Directive Macro Directive Macro DirectiveLabel .MACRO formalparameter,formalparameter Examples 100 Origin Directive Origin DirectiveChapter 101 Proc and .PROCEND Directives Proc and .PROCEND Directives102 Chapter 103 REG Directive REG DirectiveLabel .REG typedregister Label User-deﬁned register name Shlibversion Directive Shlibversion DirectiveChapter 105 Space Directive Space Directive106 Chapter 107 Spnum Pseudo-Operation Spnum Pseudo-Operation108 String and .STRINGZ Pseudo-Operations String and .STRINGZ Pseudo-OperationsChapter 109 110 Subspa Directive Subspa DirectiveName An identiﬁer that names the current subspace Chapter 111 112 Chapter 113 Version Directive Version Directive114 Word Pseudo-Operation Word Pseudo-OperationWord initvalue , initvalue Chapter 115 Directive Space Name Default Parameters Programming AidsProgramming Aids Predeﬁned Subspace Directives Shortdata Chapter 117 Programming Aids 118 Pseudo-Instruction Set 119 120 Cond Description Compare and Branch Conditions Comb and ComibChapter 121 Add and Branch Conditions Addb and Addib Description 122 Invoking the Assembler 123 Using the as Command Using the as CommandAssemble code for the architecture 124 Level ﬁlenameChapter 125 Wnumber Tables, see HP-UX Linker and LibrariesOnline User Guide 126 Using the cc Command Using the cc CommandPassing Arguments to the Assembler Wa, ,as-argument as-argument Cpp Preprocessor 128 Programming Examples 129 Binary Search for Highest Bit Position Binary Search for Highest Bit Position130 Chapter 131 Copying a String Copying a String132 Chapter 133 Dividing a Double-Word Dividend Dividing a Double-Word Dividend134 Programming Examples Chapter 135 Demonstrating the Procedure Calling Convention Demonstrating the Procedure Calling ConventionProgram Listing 136 Assembly Program Listing Chapter 137 Output of the cc -S Command Assembly Program Listing From the C CompilerOutput of the cc -S Command 138 Chapter 139 Output of the cc -S Command 140 141 Option operand 142 Chapter 143 Reserve 144 Use a general register Wrong register type usedChapter 145 Use a control register Use a space register146 Chapter 147 148 Chapter 149 150 Chapter 151 Used to invoke the assembler 152 Chapter 153 Error Messages Error Messages154 Chapter 155 156 Chapter 157 158 1027 10281029 1030 1031 10321033 1034 1035 10361037 1038 162 Chapter 163 1054 10551056 1057 Chapter 165 166 Chapter 167 168 Format keyword=value 10801081 1082 170 1088 10891090 Chapter 171 1091 10941095 1096 1097 10981099 1100 1101 11021103 1104 1105 Chapter 175 Panic Messages Panic Messages176 2005 20062007 2008 User Warning Messages User Warning Messages178 7003 70047005 7006 180 Chapter 181 182 Limit Error Messages Limit Error Messages7200 7201 7202 72037204 184 Diagnostic Messages Chapter 185 186 Branching Error Messages Branching Error MessagesChapter 187 188 Chapter 189 190 Chapter 191 192 7827 78287834 7835 7836 7837Expr 194 Index Index 195 196 Numerics Index 197 Copyright 198 HP C/HP-UX,49 Index 199 Mfctl 200 Double Index 201 See also memory 202