体系结构-研课程要点与复习

《体系结构-研课程要点与复习》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。

1、高级体系结构课程要点第一章前言计算机技术快速法进步的原因技术进步－－Moore定律发展体系结构发展体系结构演化过程现代计算机体系结构的组成高级计算机体系结构研究范畴zjpine@126.com计算机系统结构的分类Flynn分类法---定性冯氏分类法---定量第三章Instruction-LevelParallelismandItsDynamicExploitationWhatispipelining?HowisthepipeliningImplemented?Whatmakespipelininghardtoimplement?HowdoesCPIdescend?CP

2、I=1CPI<1CPI<<1IdealPerformanceforPipeliningIdealspeedupequaltoNumberofpipestagesMIPSinstructionformatWorksintheMIPS5stagepipelineTheMIPSpipeliningPipelinehazard:themajorhurdleStructuralhazardsDatahazardsControlhazardsberesolvedbyStallSolutionimaginableforStructuralhazards“doublebump”Ins

3、ertstallprovideanothermemoryportsplitinstructionmemoryanddatamemoryuseinstructionbufferfullypipelinedfunctionunitWhyallowmachinewithstructuralhazard?SolutionimaginableforDatahazardsInterlock:insertstallsDetect:DataHazardLogicForwarding:reducedatahazardstallscompilertoavoidloadstallSolut

4、ionimaginableforControlhazardsMovetheBranchComputationForwardSimplesolutionsFreezeorflushthepipelinePredict-not-taken(Predict-untaken)TreateverybranchasnottakenPredict-takenTreateverybranchastakenDelayedbrancha,b,cCancellingfunctionExtendingtheMIPSPipelinetoHandlecomplexpipelinestructur

5、ePipeliningtimeparameterLatencyInitiationintervalTheoutoforderThenewtypesofdatahazardsRAWStallsarisingWAWInstruction-LevelParallelismCPIpipelined=IdealpipelineCPI+pipelinedstallcyclesperinstruction=1+Structualstalls+RAWstalls+WARstalls+WAWstalls+ControlstallsBasicBlockILPisquitesmallDat

6、aDependenceandHazardsTrueDataDependence→RAW(Readafterwrite)NamedependenceAnti-dependence→WAR(Writeafterread)Outputdependence→WAW(Writeafterwrite)SomePropertyaboutDependencesareapropertyofprogramshazardorlengthofanystallisapropertyofthepipeline(hardware)ControlDependenciesBranchBehaviorO

7、vercomingDataHazardswithDynamicSchedulingKeyidea:Allowinstructionsbehindstalltoproceedin-orderissueout-of-orderexecutionout-of-ordercompletionDynamicSchedulingwithaScoreboardIssue:ainstructionisissuedwhenThefunctionalunitisavailableandNootheractiveinstructionhasthesamedestinati