08292014传智播客C第三期更新完毕C_AMP_GPU_编程

TamingGPUComputewithC+AMPC+AcceleratedMassiveParallelism,SteveTeixeiraDirectorofProgramManagementMicrosoftParallelComputingPlatform,Agenda,WhyGPUcompute?OverviewofC+AMPFullVisualStudioIntegrationandSupport,RapidlyChangingProcessorArchitectures,1billiontransistors45nmMulti-tasking,I/O,virtualizationSupportsgeneralcodeLowmemorybandwidthMediumlevelofparallelismDeepexecutionpipelinesHigherpowerconsumption,2billiontransistors40nmProgrammableandfixedfunctionGraphicsanddata-parallelcodeHighmemorybandwidthHighlevelofparallelismShallowexecutionpipelinesLowerpowerconsumption,Source:AMD,PerformanceGapWidensFurther,Source:NVIDIA,CurrentGPUPerformance,GPUvs.CPUPerformance,n-BodiesinC+AMP,Demo,DataParallelandGPUAcceleration,ExposeextremeperformanceofGPUsforgraphicsandcomputationProvidedeveloperstheabilitytogetsignificantperformancegainsDemandforasingleapplicationimagethatrunsonGPUhardwarefrommultiplevendors,Raytracing,Medicaltomography,LeveragingaC+ProgrammingModel,GoalsPerformance:UnleashthepowerofthehardwareProductivity:UseC+skillsforcommodityhardwarePortability:Writeonce,runonmultipleplatformsThemesProtectcodinginvestmentinthelongrunIncreaseexpressivenessashardwareevolvesLeverageexistingdeveloperskillsonlanguageandtools,C+AMP,WillbeintegratedintoVisualStudioandtheVC+CompilerBuildingontheDirectXruntimestackUbiquitousandreliableEnablesbroadrangeofdeveloperstoleveragemoderndataparallelarchitecturesHigher-levelabstractionsLow-levelhardwareaccessCodeauthoring,debugging,andprofilingsupportprovidedwithinVisualStudioWeintendtosupportalibraryecosystem,DataParallelProgrammingC=A*B,0,1,2,3,n,A,0,1,2,3,n,B,C,voidMatrixMult(float*C,constfloat*A,constfloat*B,intM,intN,intW)for(intx=0;xW;+x)for(inty=0;yN;+y)floatsum=0;for(inti=0;iM;i+)sum+=Ax*M+i*Bi*W+y;Cx*W+y=sum;,voidMatrixMult(float*C,constfloat*A,constfloat*B,intM,intN,intW)array_viewa(M,W,A),b(W,N,B);array_viewc(M,N,C);parallel_for_each(c.grid,=(indexidx)restrict(direct3d)floatsum=0;for(inti=0;ia.x;i+)sum+=a(idx.y,i)*b(i,idx.x);cidx=sum;);,voidMatrixMult(float*C,constfloat*A,constfloat*B,intM,intN,intW)parallel_for(0,W,grid,index,andarray_view,usingnamespaceConcurrency;voidMatrixMultiply(vector,gridDeterminestheshapeofdataandthescopeofcomputationindexAnN-dimensionalvectorusedtoindexapointinamultidimensionalarrayarray_viewMultidimensionalarrayofrankNwithelementtypeTContainerfordatausedonaccelerator,gride3(6,3,3);,indexi3(2,0,1);,RestrictionQualifiers,FunctionorlambdamodifierwitharestrictionqualifierRestrictionqualifiersinformcompilerof“intent”or“behavior”Allowsoptimizationsorspecialcode-genbehaviorDefinedqualifiersdirect3dandpotentiallyothersSyntaxexamples:,voidCompute(double,direct3dRestrictionQualifier,FunctionsandlambdasintendedtoexecuteonaDirect3DgraphicsdeviceCapableofexecutingonanyDX11deviceRestrictionsfollowlimitationsofDX11devicemodelShaderModel5No1-byteor2-bytedatatypesNofunctionpointersorvirtualmethodsCanonlycallotherdirect3dfunctionsManyotherrestrictionsOtherC+languagefeaturesworkasexpected,restrict(direct3d)CompilationChain,regularC+code,C+AMPcode,HLSLcodegen,fxcshadercompiler,VC+compiler,C+linker,Executable,C+sourcefile,Example:TargetRestrictions,/Overloadontargetfloatcos(float)restrict(direct3d,fpga)Baz*pBaz=newBaz(v);/errorreturn_TaylorSeries_cos(v);floatcos(floatv)restrict(cpu)return_x64_FastCos(v);/Target-polymorphiccallsitefloatfoo(floatv)returncos(v);,autorestrictionspecifier,Letsthecompilerdecideeffectiverestrictionsforinlinefunctions(notforforwarddeclarations)Directlyusingexistingtemplatetypesandalgorithms(andnewones)withoutannotationstd:complexclassstd:for_eachalgorithm,templateinlinevoidmy_generic_algorithm(Funcf)restrict(auto)f();,Inferringauto,/Compilewith/ZautonamespacestdtemplateFuncfor_each(IIfirst,IIlast,Funcf)/impliesrestrict(cpu,auto)for(;first!=last;+first)f(*first);returnf;,parallel_for_each,InitiatesparallelexecutiononanacceleratorSemantics:InvokethefunctorforeachpointinthegridArbitraryorderfortheactivitiesparallel_for_eachisas-ifsynchronousintermsofvisiblesideeffects,usingnamespaceConcurrency;voidMatrixMultiply(vector,DataParallelAccelerators,AbstractionforoneormoredataparallelacceleratorsOneormoreDirect3D11GPUsMultipleGPUsCPUvectorprocessorMany-coreCPUsHostandacceleratorareseparateinthemodelDatatransferto/fromacceleratorCouldbeoptimizedawayforintegratedmemoryarchitectureaccelerator_viewHandletoanaccelerator,CPUs,Systemmemory,GPU,PCIe,GPU,GPU,GPU,Host,Accelerator,Performance-orientedtopics,Usethreadgroups(tiles)andsharedmemoryforperformancetile_staticstoragemodifierDefinesharedmemoryforthreadsinthetiletile_barrierBarrierforallthreadsinthetileTiledformofparallel_for_eachtiled_gridtodefinedimensionstiled_indexSpecializedindexwithtilecoordinates,Matrixmultiplywithtiles,voidMatrixMultiplyTiled(vector,Exampleoftiledforall,IntegratedDeveloperTools,UseC+AMPfeaturesandclasseswithfullsupportfromtheVisualStudioIDEIntelliSensecolorizationDebugcomputeintensivecodesegmentsthatexecuteonGPUsGPUemulatorGPUhardwareConcurrencyVisualizerprovidesintegratedviewofactivityonCPUandGPU,DebuggingExperience,WellknownVisualStudiodebuggingfeaturesLaunch,Attach,Stepping,BreakpointsProcesses,DebugOutput,Modules,DisassemblyCallStack,Memory,Registers,Locals,Watch,QuickWatch,DataTipsNewfeatures(forbothCPUandGPU)ParallelStackswindow,ParallelWatchwindow,BarrierNewGPU-specificGPUThreadswindow,GPUDebugging,BringCPUdebuggingexperiencetoGPU,ConcurrencyVisualizerSupportforGPGPU,ProfilercombinesGPUsupportwiththeCPUth