ARM Optimizing C/C++ Compiler v5.2

202 Pages·2014·1 MB·English

by  Texas Instruments, Incorporated

ARM Optimizing C/C++ Compiler
v5.2
User's Guide
LiteratureNumber:SPNU151J
November2014
Contents
Preface........................................................................................................................................ 9
1 IntroductiontotheSoftwareDevelopmentTools.................................................................... 12
1.1 SoftwareDevelopmentToolsOverview................................................................................. 13
1.2 CompilerInterface.......................................................................................................... 15
1.3 ANSI/ISOStandard........................................................................................................ 15
1.4 OutputFiles................................................................................................................. 15
1.5 Utilities....................................................................................................................... 16
2 UsingtheC/C++Compiler................................................................................................... 17
2.1 AbouttheCompiler......................................................................................................... 18
2.2 InvokingtheC/C++Compiler............................................................................................. 18
2.3 ChangingtheCompiler'sBehaviorwithOptions....................................................................... 19
2.3.1 LinkerOptions..................................................................................................... 26
2.3.2 FrequentlyUsedOptions......................................................................................... 28
2.3.3 MiscellaneousUsefulOptions................................................................................... 30
2.3.4 Run-TimeModelOptions......................................................................................... 31
2.3.5 SymbolicDebuggingandProfilingOptions.................................................................... 34
2.3.6 SpecifyingFilenames............................................................................................. 35
2.3.7 ChangingHowtheCompilerInterpretsFilenames ........................................................... 35
2.3.8 ChangingHowtheCompilerProcessesCFiles.............................................................. 35
2.3.9 ChangingHowtheCompilerInterpretsandNamesExtensions............................................ 36
2.3.10 SpecifyingDirectories............................................................................................ 36
2.3.11 AssemblerOptions............................................................................................... 37
2.3.12 DeprecatedOptions.............................................................................................. 38
2.4 ControllingtheCompilerThroughEnvironmentVariables............................................................ 38
2.4.1 SettingDefaultCompilerOptions(TI_ARM_C_OPTION).................................................... 38
2.4.2 NaminganAlternateDirectory(TI_ARM_C_DIR)............................................................ 39
2.5 ControllingthePreprocessor ............................................................................................. 39
2.5.1 PredefinedMacroNames........................................................................................ 40
2.5.2 TheSearchPathfor#includeFiles............................................................................. 41
2.5.3 Supportforthe#warningand#warnDirectives............................................................... 42
2.5.4 GeneratingaPreprocessedListingFile(--preproc_onlyOption)........................................... 42
2.5.5 ContinuingCompilationAfterPreprocessing(--preproc_with_compileOption)........................... 43
2.5.6 GeneratingaPreprocessedListingFilewithComments(--preproc_with_commentOption)........... 43
2.5.7 GeneratingaPreprocessedListingFilewithLine-ControlInformation(--preproc_with_lineOption).. 43
2.5.8 GeneratingPreprocessedOutputforaMakeUtility(--preproc_dependencyOption) ................... 43
2.5.9 GeneratingaListofFilesIncludedwiththe#includeDirective(--preproc_includesOption)............ 43
2.5.10 GeneratingaListofMacrosinaFile(--preproc_macrosOption)......................................... 43
2.6 PassingArgumentstomain()............................................................................................. 44
2.7 UnderstandingDiagnosticMessages.................................................................................... 44
2.7.1 ControllingDiagnosticMessages............................................................................... 46
2.7.2 HowYouCanUseDiagnosticSuppressionOptions......................................................... 47
2.8 OtherMessages............................................................................................................ 47
2.9 GeneratingCross-ReferenceListingInformation(--gen_acp_xrefOption)......................................... 47
2.10 GeneratingaRawListingFile(--gen_acp_rawOption)............................................................... 48
2.11 UsingInlineFunctionExpansion......................................................................................... 49
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2.11.1 InliningIntrinsicOperators...................................................................................... 50
2.11.2 AutomaticInlining................................................................................................ 50
2.11.3 InliningRestrictions.............................................................................................. 50
2.12 UsingInterlist............................................................................................................... 51
2.13 ControllingApplicationBinaryInterface................................................................................. 52
2.14 VFPSupport................................................................................................................ 53
2.15 EnablingEntryHookandExitHookFunctions......................................................................... 54
3 OptimizingYourCode......................................................................................................... 55
3.1 InvokingOptimization...................................................................................................... 56
3.2 PerformingFile-LevelOptimization(--opt_level=3option)............................................................ 57
3.2.1 ControllingFile-LevelOptimization(--std_lib_func_defOptions)........................................... 57
3.2.2 CreatinganOptimizationInformationFile(--gen_opt_infoOption)......................................... 57
3.3 Program-LevelOptimization(--program_level_compileand--opt_level=3options)............................... 58
3.3.1 ControllingProgram-LevelOptimization(--call_assumptionsOption)...................................... 58
3.3.2 OptimizationConsiderationsWhenMixingC/C++andAssembly.......................................... 59
3.4 Link-TimeOptimization(--opt_level=4Option)......................................................................... 60
3.4.1 OptionHandling................................................................................................... 60
3.4.2 IncompatibleTypes............................................................................................... 61
3.5 AccessingAliasedVariablesinOptimizedCode....................................................................... 61
3.6 UseCautionWithasmStatementsinOptimizedCode............................................................... 61
3.7 AutomaticInlineExpansion(--auto_inlineOption)..................................................................... 61
3.8 UsingtheInterlistFeatureWithOptimization........................................................................... 62
3.9 DebuggingandProfilingOptimizedCode............................................................................... 64
3.9.1 ProfilingOptimizedCode......................................................................................... 64
3.10 ControllingCodeSizeVersusSpeed ................................................................................... 65
3.11 WhatKindofOptimizationIsBeingPerformed?....................................................................... 65
3.11.1 Cost-BasedRegisterAllocation................................................................................ 66
3.11.2 AliasDisambiguation ............................................................................................ 66
3.11.3 BranchOptimizationsandControl-FlowSimplification...................................................... 66
3.11.4 DataFlowOptimizations........................................................................................ 66
3.11.5 ExpressionSimplification........................................................................................ 67
3.11.6 InlineExpansionofFunctions.................................................................................. 67
3.11.7 FunctionSymbolAliasing....................................................................................... 67
3.11.8 InductionVariablesandStrengthReduction ................................................................. 67
3.11.9 Loop-InvariantCodeMotion.................................................................................... 67
3.11.10 LoopRotation................................................................................................... 67
3.11.11 InstructionScheduling.......................................................................................... 67
3.11.12 TailMerging..................................................................................................... 68
3.11.13 AutoincrementAddressing .................................................................................... 68
3.11.14 BlockConditionalizing.......................................................................................... 68
3.11.15 EpilogInlining................................................................................................... 68
3.11.16 RemovingComparisonstoZero.............................................................................. 68
3.11.17 IntegerDivisionWithConstantDivisor....................................................................... 69
3.11.18 BranchChaining................................................................................................ 69
4 LinkingC/C++Code............................................................................................................ 70
4.1 InvokingtheLinkerThroughtheCompiler(-zOption)................................................................ 71
4.1.1 InvokingtheLinkerSeparately.................................................................................. 71
4.1.2 InvokingtheLinkerasPartoftheCompileStep.............................................................. 72
4.1.3 DisablingtheLinker(--compile_onlyCompilerOption) ...................................................... 72
4.2 LinkerCodeOptimizations................................................................................................ 73
4.2.1 GenerateListofDeadFunctions(--generate_dead_funcs_listOption).................................... 73
4.2.2 GeneratingFunctionSubsections(--gen_func_subsectionsCompilerOption)........................... 73
4.3 ControllingtheLinkingProcess .......................................................................................... 74
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4.3.1 IncludingtheRun-Time-SupportLibrary....................................................................... 74
4.3.2 Run-TimeInitialization............................................................................................ 75
4.3.3 InitializationofCinitandWatchdogTimerHold............................................................... 75
4.3.4 GlobalObjectConstructors...................................................................................... 75
4.3.5 SpecifyingtheTypeofGlobalVariableInitialization.......................................................... 76
4.3.6 SpecifyingWheretoAllocateSectionsinMemory ........................................................... 77
4.3.7 ASampleLinkerCommandFile ................................................................................ 78
5 ARMC/C++LanguageImplementation.................................................................................. 79
5.1 CharacteristicsofARMC................................................................................................. 80
5.1.1 Implementation-DefinedBehavior............................................................................... 80
5.2 CharacteristicsofARMC++.............................................................................................. 84
5.3 UsingMISRA-C:2004...................................................................................................... 84
5.4 UsingtheULPAdvisor .................................................................................................... 85
5.5 DataTypes.................................................................................................................. 86
5.5.1 SizeofEnumTypes .............................................................................................. 87
5.6 Keywords.................................................................................................................... 88
5.6.1 TheconstKeyword................................................................................................ 88
5.6.2 The__interruptKeyword......................................................................................... 88
5.6.3 ThevolatileKeyword.............................................................................................. 89
5.7 C++ExceptionHandling................................................................................................... 90
5.8 RegisterVariablesandParameters...................................................................................... 91
5.8.1 LocalRegisterVariablesandParameters..................................................................... 91
5.8.2 GlobalRegisterVariables........................................................................................ 91
5.9 The__asmStatement..................................................................................................... 92
5.10 PragmaDirectives.......................................................................................................... 93
5.10.1 TheCHECK_MISRAPragma .................................................................................. 94
5.10.2 TheCHECK_ULPPragma...................................................................................... 94
5.10.3 TheCLINKPragma.............................................................................................. 94
5.10.4 TheCODE_SECTIONPragma................................................................................. 95
5.10.5 TheCODE_STATEPragma.................................................................................... 96
5.10.6 TheDATA_ALIGNPragma..................................................................................... 96
5.10.7 TheDATA_SECTIONPragma................................................................................. 97
5.10.8 TheDiagnosticMessagePragmas............................................................................ 98
5.10.9 TheDUAL_STATEPragma..................................................................................... 98
5.10.10 TheFUNC_ALWAYS_INLINEPragma...................................................................... 99
5.10.11 TheFUNC_CANNOT_INLINEPragma...................................................................... 99
5.10.12 TheFUNC_EXT_CALLEDPragma.......................................................................... 99
5.10.13 TheFUNCTION_OPTIONSPragma....................................................................... 100
5.10.14 TheINTERRUPTPragma.................................................................................... 100
5.10.15 TheLOCATIONPragma..................................................................................... 101
5.10.16 TheMUST_ITERATEPragma .............................................................................. 102
5.10.17 TheNOINITandPERSISTENTPragmas ................................................................. 103
5.10.18 TheNO_HOOKSPragma.................................................................................... 104
5.10.19 ThePACKPragma............................................................................................ 104
5.10.20 TheRESET_MISRAPragma................................................................................ 105
5.10.21 TheRESET_ULPPragma................................................................................... 105
5.10.22 TheRETAINPragma......................................................................................... 105
5.10.23 TheSET_CODE_SECTIONandSET_DATA_SECTIONPragmas.................................... 106
5.10.24 TheSWI_ALIASPragma..................................................................................... 107
5.10.25 TheTASKPragma............................................................................................ 108
5.10.26 TheUNROLLPragma........................................................................................ 108
5.10.27 TheWEAKPragma........................................................................................... 109
5.11 The_PragmaOperator .................................................................................................. 109
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5.12 ApplicationBinaryInterface............................................................................................. 110
5.12.1 TI_ARM9_ABI................................................................................................... 110
5.12.2 TIABI(Deprecated)............................................................................................. 110
5.12.3 ARMABIv2orEABI............................................................................................ 111
5.13 ARMInstructionIntrinsics................................................................................................ 111
5.14 ObjectFileSymbolNamingConventions(Linknames).............................................................. 119
5.15 InitializingStaticandGlobalVariablesinTIARM9ABIandTIABIModes ....................................... 119
5.15.1 InitializingStaticandGlobalVariablesWiththeLinker.................................................... 120
5.15.2 InitializingStaticandGlobalVariablesWiththeconstTypeQualifier................................... 120
5.16 ChangingtheANSI/ISOC/C++LanguageMode..................................................................... 121
5.16.1 EnablingC99Mode(--c99).................................................................................... 121
5.16.2 CompatibilityWithK&RC(--kr_compatibleOption) ....................................................... 122
5.16.3 EnablingStrictANSI/ISOModeandRelaxedANSI/ISOMode(--strict_ansiand--relaxed_ansi
Options)........................................................................................................... 123
5.16.4 EnablingEmbeddedC++Mode(--embedded_cppOption)............................................... 124
5.17 GNULanguageExtensions ............................................................................................. 124
5.17.1 Extensions....................................................................................................... 124
5.17.2 FunctionAttributes.............................................................................................. 126
5.17.3 VariableAttributes.............................................................................................. 126
5.17.4 TypeAttributes.................................................................................................. 126
5.17.5 Built-InFunctions............................................................................................... 127
5.18 AUTOSAR................................................................................................................. 127
5.19 CompilerLimits............................................................................................................ 128
6 Run-TimeEnvironment...................................................................................................... 129
6.1 MemoryModel............................................................................................................ 130
6.1.1 Sections........................................................................................................... 130
6.1.2 C/C++SystemStack............................................................................................ 131
6.1.3 DynamicMemoryAllocation.................................................................................... 132
6.1.4 InitializationofVariablesinTI_ARM9_ABIandTIABI ..................................................... 132
6.2 ObjectRepresentation................................................................................................... 132
6.2.1 DataTypeStorage............................................................................................... 132
6.2.2 BitFields.......................................................................................................... 136
6.2.3 CharacterStringConstants..................................................................................... 138
6.3 RegisterConventions.................................................................................................... 139
6.4 FunctionStructureandCallingConventions.......................................................................... 142
6.4.1 HowaFunctionMakesaCall.................................................................................. 143
6.4.2 HowaCalledFunctionResponds............................................................................. 144
6.4.3 CExceptionHandlerCallingConvention..................................................................... 144
6.4.4 AccessingArgumentsandLocalVariables................................................................... 145
6.4.5 GeneratingLongCalls(-mlOption)in16-bitMode......................................................... 145
6.5 AccessingLinkerSymbolsinCandC++.............................................................................. 145
6.6 InterfacingCandC++WithAssemblyLanguage.................................................................... 145
6.6.1 UsingAssemblyLanguageModulesWithC/C++Code.................................................... 145
6.6.2 AccessingAssemblyLanguageFunctionsFromC/C++ ................................................... 146
6.6.3 AccessingAssemblyLanguageVariablesFromC/C++.................................................... 147
6.6.4 SharingC/C++HeaderFilesWithAssemblySource....................................................... 148
6.6.5 UsingInlineAssemblyLanguage.............................................................................. 148
6.6.6 ModifyingCompilerOutput..................................................................................... 148
6.7 InterruptHandling......................................................................................................... 149
6.7.1 SavingRegistersDuringInterrupts............................................................................ 149
6.7.2 UsingC/C++InterruptRoutines ............................................................................... 149
6.7.3 UsingAssemblyLanguageInterruptRoutines............................................................... 149
6.7.4 HowtoMapInterruptRoutinestoInterruptVectors......................................................... 150
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6.7.5 UsingSoftwareInterrupts....................................................................................... 151
6.7.6 OtherInterruptInformation..................................................................................... 151
6.8 IntrinsicRun-Time-SupportArithmeticandConversionRoutines.................................................. 152
6.8.1 NamingConventions............................................................................................ 152
6.8.2 CPSRRegisterandInterruptIntrinsics....................................................................... 154
6.9 Built-InFunctions......................................................................................................... 155
6.10 SystemInitialization...................................................................................................... 156
6.10.1 SystemPre-Initialization....................................................................................... 156
6.10.2 Run-TimeStack................................................................................................. 157
6.10.3 TIARM9ABI/TIABIAutomaticInitializationofVariables.................................................. 157
6.10.4 EABIAutomaticInitializationofVariables................................................................... 159
6.10.5 InitializationTables............................................................................................. 165
6.11 Dual-StateInterworkingUnderTIABI(Deprecated).................................................................. 167
6.11.1 LevelofDual-StateSupport................................................................................... 167
6.11.2 Implementation.................................................................................................. 168
7 UsingRun-Time-SupportFunctionsandBuildingLibraries................................................... 171
7.1 CandC++Run-TimeSupportLibraries............................................................................... 172
7.1.1 LinkingCodeWiththeObjectLibrary......................................................................... 172
7.1.2 HeaderFiles...................................................................................................... 172
7.1.3 ModifyingaLibraryFunction................................................................................... 172
7.1.4 SupportforStringHandling..................................................................................... 173
7.1.5 MinimalSupportforInternationalization...................................................................... 173
7.1.6 AllowableNumberofOpenFiles.............................................................................. 173
7.1.7 NonstandardHeaderFilesintheSourceTree .............................................................. 173
7.1.8 LibraryNamingConventions................................................................................... 174
7.2 TheCI/OFunctions...................................................................................................... 175
7.2.1 High-LevelI/OFunctions ....................................................................................... 175
7.2.2 OverviewofLow-LevelI/OImplementation.................................................................. 176
7.2.3 Device-DriverLevelI/OFunctions............................................................................. 180
7.2.4 AddingaUser-DefinedDeviceDriverforCI/O.............................................................. 184
7.2.5 ThedevicePrefix................................................................................................ 185
7.3 HandlingReentrancy(_register_lock()and_register_unlock()Functions)........................................ 187
7.4 Library-BuildProcess..................................................................................................... 188
7.4.1 RequiredNon-TexasInstrumentsSoftware.................................................................. 188
7.4.2 UsingtheLibrary-BuildProcess............................................................................... 188
7.4.3 Extendingmklib.................................................................................................. 191
8 C++NameDemangler........................................................................................................ 192
8.1 InvokingtheC++NameDemangler.................................................................................... 193
8.2 C++NameDemanglerOptions......................................................................................... 193
8.3 SampleUsageoftheC++NameDemangler......................................................................... 194
A Glossary.......................................................................................................................... 195
B RevisionHistory............................................................................................................... 200
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List of Figures
1-1. ARMSoftwareDevelopmentFlow....................................................................................... 13
6-1. CharandShortDataStorageFormat.................................................................................. 133
6-2. 32-BitDataStorageFormat............................................................................................. 134
6-3. Double-PrecisionFloating-PointDataStorageFormat.............................................................. 135
6-4. Bit-FieldPackinginBig-EndianandLittle-EndianFormats......................................................... 136
6-5. UseoftheStackDuringaFunctionCall............................................................................... 143
6-6. AutoinitializationatRunTime........................................................................................... 158
6-7. InitializationatLoadTime ............................................................................................... 158
6-8. AutoinitializationatRunTimeinEABIMode.......................................................................... 160
6-9. InitializationatLoadTimeinEABIMode.............................................................................. 164
6-10. ConstructorTableinEABIMode....................................................................................... 164
6-11. FormatofInitializationRecordsinthe.cinitSection................................................................. 165
6-12. FormatofInitializationRecordsinthe.pinitSection................................................................. 166
List of Tables
2-1. ProcessorOptions ......................................................................................................... 19
2-2. OptimizationOptions ...................................................................................................... 19
2-3. AdvancedOptimizationOptions ......................................................................................... 20
2-4. DebugOptions.............................................................................................................. 20
2-5. AdvancedDebugOptions................................................................................................. 21
2-6. IncludeOptions ............................................................................................................ 21
2-7. ULPAdvisorOptions....................................................................................................... 21
2-8. ControlOptions ............................................................................................................ 21
2-9. LanguageOptions.......................................................................................................... 21
2-10. ParserPreprocessingOptions............................................................................................ 22
2-11. PredefinedSymbolsOptions ............................................................................................. 22
2-12. DiagnosticMessageOptions............................................................................................. 22
2-13. Run-TimeModelOptions.................................................................................................. 23
2-14. Entry/ExitHookOptions................................................................................................... 24
2-15. LibraryFunctionAssumptionsOptions.................................................................................. 24
2-16. AssemblerOptions......................................................................................................... 24
2-17. FileTypeSpecifierOptions............................................................................................... 24
2-18. DirectorySpecifierOptions................................................................................................ 25
2-19. DefaultFileExtensionsOptions.......................................................................................... 25
2-20. CommandFilesOptions................................................................................................... 25
2-21. MISRA-C:2004Options.................................................................................................... 25
2-22. LinkerBasicOptions....................................................................................................... 26
2-23. FileSearchPathOptions.................................................................................................. 26
2-24. CommandFilePreprocessingOptions.................................................................................. 26
2-25. DiagnosticMessageOptions............................................................................................. 26
2-26. LinkerOutputOptions ..................................................................................................... 27
2-27. SymbolManagementOptions............................................................................................ 27
2-28. Run-TimeEnvironmentOptions.......................................................................................... 27
2-29. Link-TimeOptimizationOptions.......................................................................................... 28
2-30. MiscellaneousOptions..................................................................................................... 28
2-31. CompilerBackwards-CompatibilityOptionsSummary................................................................ 38
2-32. PredefinedARMMacroNames.......................................................................................... 40
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2-33. RawListingFileIdentifiers................................................................................................ 48
2-34. RawListingFileDiagnosticIdentifiers................................................................................... 49
3-1. InteractionBetweenDebuggingandOptimizationOptions........................................................... 57
3-2. OptionsThatYouCanUseWith--opt_level=3......................................................................... 57
3-3. SelectingaFile-LevelOptimizationOption............................................................................. 57
3-4. SelectingaLevelforthe--gen_opt_infoOption........................................................................ 57
3-5. SelectingaLevelforthe--call_assumptionsOption................................................................... 58
3-6. SpecialConsiderationsWhenUsingthe--call_assumptionsOption................................................ 59
3-7. InteractionBetweenDebuggingandOptimizationOptions........................................................... 64
4-1. InitializedSectionsCreatedbytheCompilerforTIARM9ABIandTIABI(deprecated).......................... 77
4-2. InitializedSectionsCreatedbytheCompilerforEABI................................................................ 77
4-3. UninitializedSectionsCreatedbytheCompiler........................................................................ 77
5-1. ARMC/C++DataTypes................................................................................................... 86
5-2. EABIEnumeratorTypes................................................................................................... 86
5-3. ARMIntrinsicSupportbyTarget........................................................................................ 111
5-4. ARMCompilerIntrinsics................................................................................................. 114
5-5. GCCLanguageExtensions ............................................................................................. 124
6-1. SummaryofSectionsandMemoryPlacement....................................................................... 131
6-2. DataRepresentationinRegistersandMemory ...................................................................... 132
6-3. HowRegisterTypesAreAffectedbytheConventions.............................................................. 139
6-4. RegisterUsage ........................................................................................................... 139
6-5. VFPRegisterUsage...................................................................................................... 140
6-6. NeonRegisterUsage.................................................................................................... 141
6-7. NamingConventionPrefixes............................................................................................ 152
6-8. SummaryofRun-Time-SupportArithmeticandConversionFunctions............................................ 152
6-9. Run-Time-SupportFunctionRegisterUsageConventions.......................................................... 153
6-10. CPSRandInterruptC/C++CompilerIntrinsics....................................................................... 154
6-11. SelectingaLevelofDual-StateSupport............................................................................... 167
7-1. ThemklibProgramOptions............................................................................................. 190
B-1. RevisionHistory........................................................................................................... 200
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Preface
SPNU151J–November2014
Read This First
About This Manual
TheARMOptimizingC/C++CompilerUser'sGuide explainshowtousethesecompiler tools:
• Compiler
• Librarybuildutility
• C++namedemangler
ThecompileracceptsCandC++codeconformingtotheInternationalOrganizationfor Standardization
(ISO)standardsfortheselanguages.Thecompilersupports boththe1989and1999versionsoftheC
languageandthe2003versionoftheC++language.
Thisuser'sguidediscussesthecharacteristicsoftheC/C++compiler.It assumesthat youalreadyknow
howtowriteC/C++programs. TheCProgrammingLanguage(secondedition), byBrianW.Kernighan
andDennisM.Ritchie,describesCbasedontheISOCstandard. YoucanusetheKernighanand Ritchie
(hereafterreferredtoasK&R)bookasasupplementtothismanual.ReferencestoK&RC(asopposed to
ISOC)inthismanualrefertotheClanguageasdefinedinthefirsteditionofKernighanandRitchie's The
CProgrammingLanguage.
Notational Conventions
Thisdocumentusesthefollowingconventions:
• Programlistings,programexamples,andinteractivedisplaysareshowninaspecial typeface.
Interactivedisplaysuseaboldversionofthespecialtypefacetodistinguishcommandsthat you enter
fromitemsthatthesystemdisplays(suchasprompts,commandoutput,error messages, etc.).
Hereis asampleofCcode:
#include <stdio.h>
main()
{ printf("hello, cruel world\n");
}
• Insyntaxdescriptions,theinstruction,command, ordirectiveisina boldtypefaceandparametersare
inanitalictypeface.Portionsofasyntaxthat areinboldshouldbeenteredasshown; portionsof a
syntaxthatareinitalicsdescribethetypeofinformationthat shouldbeentered.
• Squarebrackets([and])identifyanoptionalparameter.If youuseanoptionalparameter,you specify
theinformationwithinthebrackets.Unlessthesquarebracketsareinthe boldtypeface,donotenter
thebracketsthemselves.Thefollowingisanexampleofacommandthat hasanoptionalparameter:
armcl[options][filenames][--run_linker [link_options][object files]]
• Braces({and})indicatethatyoumustchooseoneoftheparameterswithinthebraces; youdo not
enterthebracesthemselves.Thisisanexampleofacommandwithbracesthat arenotincludedinthe
actualsyntaxbutindicatethatyoumustspecifyeitherthe--rom_modelor--ram_modeloption:
armcl--run_linker {--rom_model|--ram_model}filenames[--output_file= name.out]
--library=libraryname
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• Inassemblersyntaxstatements,column1isreservedfor thefirstcharacterofalabelorsymbol.Ifthe
labelorsymbol isoptional,itisusuallynotshown. If alabelorsymbolisarequiredparameter,itis
shownstartingagainsttheleftmarginofthebox,asintheexamplebelow.Noinstruction,command,
directive,orparameter,otherthanasymbolorlabel,canbeginincolumn1.
symbol.usect "sectionname",sizeinbytes[,alignment]
• Somedirectivescanhaveavaryingnumberofparameters.Forexample,the.bytedirective. This
syntaxisshownas[,..., parameter].
• TheARM®16-bitinstructionsetisreferred toas16-BIS.
• TheARM32-bitinstructionsetisreferredtoas32-BIS.
Related Documentation
Youcanusethefollowingbookstosupplementthisuser'sguide:
ANSI X3.159-1989,ProgrammingLanguage-C(Alternateversionofthe1989CStandard),American
NationalStandardsInstitute
ISO/IEC9899:1989,InternationalStandard-ProgrammingLanguages-C(The1989CStandard),
InternationalOrganizationforStandardization
ISO/IEC9899:1999,InternationalStandard-ProgrammingLanguages-C(The1999CStandard),
InternationalOrganizationforStandardization
ISO/IEC14882-2003,InternationalStandard-ProgrammingLanguages-C++(The2003C++
Standard),InternationalOrganizationfor Standardization
TheCProgrammingLanguage(secondedition),byBrianW.KernighanandDennisM. Ritchie,
publishedbyPrentice-Hall,EnglewoodCliffs,NewJersey, 1988
TheAnnotatedC++ReferenceManual,MargaretA.EllisandBjarneStroustrup,publishedbyAddison-
WesleyPublishingCompany,Reading,Massachusetts,1990
C:AReferenceManual(fourth edition),bySamuelP.Harbison, andGuyL.SteeleJr.,publishedby
PrenticeHall,EnglewoodCliffs,NewJersey
ProgrammingEmbeddedSystemsinCandC++,byMichaelBarr,AndyOram(Editor),publishedby
O'Reilly& Associates;ISBN:1565923545,February1999
ProgramminginC,SteveG.Kochan,HaydenBookCompany
TheC++ProgrammingLanguage(secondedition),BjarneStroustrup,publishedbyAddison-Wesley
PublishingCompany,Reading,Massachusetts,1990
ToolInterfaceStandards(TIS)DWARFDebuggingInformationFormatSpecificationVersion2.0,
TISCommittee,1995
DWARFDebuggingInformationFormatVersion3,DWARFDebuggingInformationFormatWorkgroup,
FreeStandardsGroup,2005(http://dwarfstd.org)
SystemVABIspecification(http://www.sco.com/developers/gabi/)
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