编译器keil的优化选项针对ARM.docx

《编译器keil的优化选项针对ARM.docx》由会员上传分享，免费在线阅读，更多相关内容在工程资料-天天文库。

1、编译器_keil的优化选项问题分类： 编译器类2013-01-1114:12 280人阅读 评论(0) 收藏 举报applicationApplicationcompilationcompileroptimizationperformancePerformance最近发现在keil编译的时候，出现莫名的问题，貌似代码有被优化掉的问题，后来查了下相关的资料，貌似懂了点。我选择的是默认的default优化方式，上网看了下，默认的是level2级别优化，最后选择level0就没有问题了下面是网上找的资料，介绍了优化功能介绍GettingtheBestOptimizedCodefo

2、ryourEmbeddedApplication ARMCompilationTools TheARMCompilationToolsaretheonlycompilationtoolsco-developedwiththeARMprocessors,andspecifically designedtooptimallysupporttheARMarchitecture.Theyarearesultof20yearsofdevelopment,andarerecognizedasthe industry-leadingCandC++compilationtoolsforth

3、eARM,Thumb,andThumb-2instructionssets. TheARMCompilationtoolsconsistof: • TheARMCompiler,whichenablesyoutocompileCandC++code.Itisanoptimizingcompiler,andfeatures command-lineoptionstoenableyoutocontrolthelevelofoptimization • LinkerandUtilities,whichassignaddressesandlayoutsectionsofcodeto

4、formafinalimage • Aselectionoflibraries,includingtheISOstandardClibraries,andtheMicroLIBClibrarywhichisoptimizedfor embeddedapplications • Assembler,whichgeneratesmachinecodeinstructionsfrom ARM,ThumborThumb-2assembly-level sourcecode  CompilerOptionsforEmbeddedApplications  TheARMCompilat

5、ionToolsincludeanumberofcompileroptimizationstohelpyoubesttargetyourcodeforyourchosen microcontrollerdeviceand applicationarea.  TheycanbeaccessedfromwithinµVisionbyclickingonProject– OptionsforTarget. Theoptionsdescribedthisdocument canbefoundontheTarget and C/C++ tabs of the OptionsforTa

6、rgets dialog.  MDKCompilerOptimizations  • Cross-Module Optimization takesinformationfromapriorbuildandusesittoplaceUNUSEDfunctionsintotheir ownELFsectioninthecorrespondingobjectfile.ThisoptionisalsoknownasLinkerFeedback,andrequiresyouto buildyourapplicationtwicetotakeadvantageofitforreduc

7、edcodesize.  Cross-ModuleOptimizationhasbeenshowntoreducecodesize,byremovingunusedfunctionsfromyourapplication.It canalsoimprovetheperformance ofyourapplication,byallowingmodulestoshareinlinecode.  • The MicroLIB Clibrary hasbeenoptimizedtoreducethesizeofembed