TheMorphProjectLateCodeModi ficationHARVARDUNIVE RSITYDi
erdescribingtheMORPHproject Instrume ntationandOptimizat
deLayout,toappearinThe1997U SE NIXWindowsNTWorkshop.J.Br
ethebenefitofinter-moduleJI  TCLforWin32applicationsonWi
chweinterposeanadditionalph aseofoptimizationbetwee nthe
heMorphtestbedwillmakefeedb ack-base doptimizationspract
erformanceofexecutableprogr ams.Obtainingandunde rstandi
gtherequirementofprofiledat a.Thelatenature ofthisoptimi
le-basedandotherplatformspe  cificoptimizations.Ourgoali
eresultsofaccurateperforman cemeasurementsproactive ly.T
icalandautomatic.Asapartofa chievingthisgoal,wehave impl
timeanexecutablemoduleispro ducedbythelinkerandwhenthe i
visionofEngineeringandAppli edSciencesIntheMorphProje ct
ndoingsoistochangeexecutabl eprogramsfromadead-e ndintoa
fWashington.TheEtchtracepag eatHarvard.Aposterde scribin
eferencestreambyselectingth eorderofproceduresinthete xt
zationmakesitpossibletoimpl ementprocedureorde ringsthat
ngsuchinformationisthegoalo fourprojectonUnde rstandingB
ementedacontinuousmonitorin gsystemwhichcolle ctsprofile
cutableprogramstobere-optim ized('morphe d')toapplyprofi
onofWIN32/IntelExecutablesw ithEtchJust-in-timeCode Layo
achineSUIF.Morphtechnologyw illmakeiteasytoapplypre cise
esmoreefficiently.Etchisajo intprojectbetweenUnive rsity
TCLcanprovideimprovementsin instructioncachepe rformance
nceofcomputersystemsthrough late-code modification,inwhi
performancemeasurementinfor mationdirectlytoimprovethe p
rbitraryinstructions(forexa mple,totrace,orperformcove r
imizations.TheMorphTestbedI nstrume ntationandOptimizati
mithStudentsNickGloyZhengWa ngCatherine ZhangPublication
programperformanceevaluatio nandoptimizationsystem,de ve
lopedforIntelx86platformsru nningtheWindows/NTope rating
system.Thesystemallowsyouan notateexistingbinarie switha
ndowsNT.ImprovingInstructio nLocalitywithJust-In-Time Co
segmentduringprogramexecuti on.Bydeterminingprocedure pl
acementdynamically,thismeth odprovidesanoptimizedproce d
urelayoutwithoutrequiringpr ofiledata.Wehave foundthatJI
icallybytheMorphsystem.Ouro ptimizationsystemisbase donM
L,PS(1049KB).Aversionofthis paperwillappearinthe 16thACM
fcurrentprofile-basedtechni ques.WeareusingEtchtoe xplor
weareexploringnewwaystounde rstandandimprovethepe rforma
sSystemSupportforAutomaticP  rofilingandOptimization.HTM
SymposiumonOperatingSystemP rinciples.Technicalre port:P
crossexecutableandDLLbounda ries,ove rcomingalimitationo
informationwithoverheadofle ssthan1%.Theprofile informat
nstructionsareactuallyexecu tedontheCPU.Morphpermitse xe
resourcethatpermitsanunlimi tednumberofupdatesandre -opt
utTheMorphTestbedIntheMorph testbedweareexploringsyste m
ionisusedbyasuiteofoptimiza tionswhichareapplie dautomat
rofile-BasedOptimizationswi thStatisticalProfile s.Apost
ofWashingtonandHarvard.TheE tchhomepageattheUnive rsityo
gEtch,Just-In-TimeCodeLayou tJust-In-Timecode layout(JIT
CL)isanewmethodforimproving the localityofaninstructionr
sandcompilertechniqueswhich willmakeitpossible toapplyth
ionofWIN32/IntelExecutables withEtchE tchisanapplication
ageanalysis),ortorewriteane xistingbinarysothatitexe cut
ehaviorofCommoditySoftwareS ystems.FacultyBradChenMike S
comparabletoprofile-basedla youtstrategies,while avoidin
adleyChen(bchen@eecs.harvar d.edu )..................PbN