復(fù)旦信息科學(xué)與工程學(xué)院考試試題csapp exama

Problem1.(15ConsiderthefollowingassemblycodeforaCforProblem1.(15ConsiderthefollowingassemblycodeforaCforjleBasedontheassemblyabove,fillinthebelowincorrespondingCsourcecode.(Note:youmayonlyusethesymbolicx,y,andresultinyourexpressionsbelow—donotuseregisterintloop(intx,int{for ; ;result++) } return}第2Problem2.(12ConsiderthefollowingincompletedefinitionofaCstructalongwithincompletecodeforafunctionProblem2.(12ConsiderthefollowingincompletedefinitionofaCstructalongwithincompletecodeforafunctionfuncgivenstructnode structnode*next;structnode*prev;}node_tn;node_tm= m->y/=16;}WhenthisCcodewascompiledonanIA-32machinerunningLinux,）followingassemblycodewasgeneratedforfunctionGiventhesecodefragments,fillintheblanksintheCcodegivenNotethatthereisauniqueanswer.Thetypesmustbechosenfromfollowingtable,assumingthesizesandalignment第3122448122448Problem3.(15ThefollowingproblemconcernsoptimizingaprocedureforperformanceProblem3.(15ThefollowingproblemconcernsoptimizingaprocedureforperformanceonanIntelPentiumIII.RecallthecharacteristicsofthefunctionalunitsforthisConsiderthefollowingtwoLoopintloop1(int*a,intx,int{inty=x*x;inti;for(i=0;i<n;i++)x=y*a[i];return}Loopintloop2(int*a,intx,int{inty=x*x;inti;for(i=0;i<n;i++)x=x*a[i];return}WhencompiledwithGCC,weobtainthefollowingassemblycodeforinnerLoopLoopononeofFishmachines,findthatLoop1requiresclockcyclesperiteration,whileLoop2requires第4LatencyIssueIntegerAddIntegerMultiplyIntegerDivideFloatingPointMultiplyFloatingPointDivideLoadorStore(CacheHit)1435111121A.ExplainhowitisthatLoopA.ExplainhowitisthatLoop1isfasterthanLoop2,eventhoughitonemoreB.Byusingthecompilerflag-funroll-loops,wecancompilethecodeuse4-wayloopunrolling.ThisspeedsupLoop1.Explain）C.Evenwithloopunrolling,wefindtheperformanceofLoop2thesame.ExplainProblem4.(24Thisproblemtestsyourunderstandingofcacheconflictmisses.thefollowingmatrixtransposeintarray[2][2];transpose(arraydst,arraysrc){i,for(i=0;i<2;i++){for(j=0;j<2;j++){dst[j][i]第5}}}runningonahypotheticalmachinewiththefollowing·sizeof(int)==·Thesrcarraystartsataddress0andthedstarraystartsataddress·There}}}runningonahypotheticalmachinewiththefollowing·sizeof(int)==·Thesrcarraystartsataddress0andthedstarraystartsataddress·ThereisasingleL1cachethatisdirectmappedandwrite-allocate,withblocksizeof8·Accessestothesrcanddstarraysaretheonlysourcesofreadandmisses,A.Supposethecachehasatotalsizeof16databytes(i.e.,theblocktimesthenumberofsetsis16bytes)andthatthecacheisinitiallyThenforeachrowandcol,indicatewhethereachaccesstosrc[row][col]dst[row][col]isahit(h)oramiss(m).Forexample,readingsrc[0][0]ismissandwritingdst[0][0]isalsoaB.RepeatpartAforacachewithatotalsizeof32data第6srcColColRowmRowdstColColRowmRowsrcColColRowmRowdstColColRowmRowProblem5.(24ThisproblemtestsyourProblem5.(24Thisproblemtestsyourunderstandingofexceptionalcontrolflowinprograms.AssumewearerunningcodeonaUnixproblemsallconcernthevalueofthevariablePartI(9intmain(){intfor(i=0;i<2;counterprintf("counter=%d\n",}printf("counter=%d\n",counter);return0;}A.Howmanytimeswouldthevalueofcounterbeprinted? ）B.Whatisthevalueofcounterprintedinthefirstline? C.Whatisthevalueofcounterprintedinthelastline? PartII(9pid_tintcounter=voidhandler1(int{counterprintf("counter=%d\n",fflush(stdout);/*Flushestheprintedstringtostdout*/kill(pid,SIGUSR1);}第7voidhandler2(intvoidhandler2(int{counter+=printf("counter=%d\n",counter);}voidmain()if((pid=fork())==0){kill(getppid(),SIGUSR1);while(1){};}elsepid_tp;intif((p=wait(&status))>{counter+=printf("counter=%d\n",}}}WhatistheoutputofthisPartIII(6intcounter=0;{counter}int{intfor(i=0;i<5;i++){if(fork()0){}}/*waitforallchildrentodie第8while(wait(NULL)!=-1);return0;}A.Doestheprogramoutputthesamewhile(wait(NULL)!=-1);return0;}A.Doestheprogramoutputthesamevalueofcountereverytimewe B.IftheanswertoAisYes,indicatethevalueofthecounterOtherwise,listallpossiblevaluesofthecounterAnswer:counter= ）Problem6.(22Thefollowingproblemconcernsthewayvirtualaddressesareintophysical·Thememoryisbyte·Memoryaccessesareto1-bytewords(not4-byte·Virtualaddressesare16bits·Physicaladdressesare13bits·Thepagesizeis512·TheTLBis8-waysetassociativewith16total·Thecacheis2-waysetassociative,witha4bytelinesizeand16totalInthefollowingtables,allnumbersaregiveninhexadecimal.contentsoftheTLB,thepagetableforthefirst32pages,andthecacheare第9PartI(9A.Thebelowshowstheformatofavirtualaddress.Indicatelabelingthediagram)PartI(9A.Thebelowshowstheformatofavirtualaddress.Indicatelabelingthediagram)thefields(iftheyexist)thatwouldbeusedtothefollowing:(Ifafielddoesn’texist,don’tdrawitontheThevirtualpageThevirtualpage第102-waySetAssociativeTag Tag 01234567 99112355590B0103058406B2436D8F09A1B2C4DEBB77330000C00FPage 0 1 TheTLB TheTLB 987654 10B.Theboxbelowshowstheformatofaphysicaladdress.labelingthediagram)thefieldsthatwouldusedThephysical TheTLB TheTLB 987654 10B.Theboxbelowshowstheformatofaphysicaladdress.labelingthediagram)thefieldsthatwouldusedThephysicalpage）ThephysicalpageTheblockoffsetwithinthecacheThecacheThecache 10PartII(13Forthegivenvirtualaddress,indicatetheTLBphysicaladdress,andthecachebytevaluereturnedinhex.IndicatetheTLBmisses,whetherapagefaultoccurs,andwhetheracachemissIfthereisacachemiss,enter“-”for“CacheBytereturned”.Ifthereisafault,enter“-”for“P