Chad Verbowski via llvm-dev
2020-Aug-11 05:42 UTC
[llvm-dev] opt - replicating multiple passes from -O3 -debug-pass=Executions
Hello, I am trying to replicate the output from opt -O3 foo.bc -o foo.opt.bc by specifying the individual passes instead of the -O3 flag. Looking at the passes from opt -O3 foo.bc -o foo.bc -debug-pass=Executions it seems there are two passes being run. When I run the flags indicated for the two passes specified in the 'Pass Arguments:' as two sequential opt processes or a single opt process with the concatenated flags I get a different binary result compared to the O3 run. (Note I had to remove the -targetpassconfig flag and add -spec-exec-only-if-divergent-target to the second pass to get my run to match O3's second pass.) Comparing the -debug-pass=Executions from my runs with the O3 run, it seems the first pass in my run has additional 'TargetLibrary Information', 'Target Pass Configuration' and the 'Module Pass Manager' entries compared to O3 (copied below). My output shows the 'Pass Arguments:' line has automatically added -targetpassconfig -verify -writebitcode, and the -targetlibinfo flag was moved to the start. Is there a way I can address these differences to enable replicating the -O3 first and second passes using opt flags? Thanks for considering this, -Chad (Opt -O3 first pass) Pass Arguments: -tti -tbaa -scoped-noalias -assumption-cache-tracker -targetlibinfo -verify -ee-instrument -simplifycfg -domtree -sroa -early-cse -lower-expect Target Transform Information Type-Based Alias Analysis Scoped NoAlias Alias Analysis Assumption Cache Tracker Target Library Information FunctionPass Manager Module Verifier Instrument function entry/exit with calls to e.g. mcount() (pre inlining) Simplify the CFG Dominator Tree Construction SROA Early CSE Lower 'expect' Intrinsics (My Run): opt in.bc -o out.bc -debug-pass=Executions -tti -tbaa -scoped-noalias -assumption-cache-tracker -targetlibinfo -verify -ee-instrument -simplifycfg -domtree -sroa -early-cse -lower-expect Pass Arguments: * -targetlibinfo* -tti *-targetpassconfig* -tbaa -scoped-noalias -assumption-cache-tracker -verify -ee-instrument -simplifycfg -domtree -sroa -early-cse -lower-expect *-verify -write-bitcode* *Target Library Information* Target Transform Information Target Pass Configuration Type-Based Alias Analysis Scoped NoAlias Alias Analysis Assumption Cache Tracker *ModulePass Manager* FunctionPass Manager Module Verifier Instrument function entry/exit with calls to e.g. mcount() (pre inlining) Simplify the CFG Dominator Tree Construction SROA Early CSE Lower 'expect' Intrinsics -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20200810/4bf3569c/attachment.html>
Chad Verbowski via llvm-dev
2020-Aug-11 17:14 UTC
[llvm-dev] opt - replicating multiple passes from -O3 -debug-pass=Executions
Update: Comparing the -print-before-all and -print-after-all for -O3 and the run with the flags, I see a difference starting with the 7th (of 8) "*** IR Dump After Simplify the CFG ***" which I assume is the -simplifycfg flag. Is there any known reason -simplifycfg would behave differently if the pipeline of passes up to this point are identical (order and their input and output)? Thanks. On Mon, Aug 10, 2020 at 10:42 PM Chad Verbowski <chad at verbowski.com> wrote:> Hello, > > I am trying to replicate the output from opt -O3 foo.bc -o foo.opt.bc by > specifying the individual passes instead of the -O3 flag. > > Looking at the passes from opt -O3 foo.bc -o foo.bc > -debug-pass=Executions it seems there are two passes being run. When I run > the flags indicated for the two passes specified in the 'Pass Arguments:' > as two sequential opt processes or a single opt process with the > concatenated flags I get a different binary result compared to the O3 run. > (Note I had to remove the -targetpassconfig flag and > add -spec-exec-only-if-divergent-target to the second pass to get my run to > match O3's second pass.) > > Comparing the -debug-pass=Executions from my runs with the O3 run, it > seems the first pass in my run has additional 'TargetLibrary Information', > 'Target Pass Configuration' and the 'Module Pass Manager' entries compared > to O3 (copied below). My output shows the 'Pass Arguments:' line has > automatically added -targetpassconfig -verify -writebitcode, and the > -targetlibinfo flag was moved to the start. > > Is there a way I can address these differences to enable replicating the > -O3 first and second passes using opt flags? > > Thanks for considering this, > > -Chad > > (Opt -O3 first pass) Pass Arguments: -tti -tbaa -scoped-noalias > -assumption-cache-tracker -targetlibinfo -verify -ee-instrument > -simplifycfg -domtree -sroa -early-cse -lower-expect > Target Transform Information > Type-Based Alias Analysis > Scoped NoAlias Alias Analysis > Assumption Cache Tracker > Target Library Information > FunctionPass Manager > Module Verifier > Instrument function entry/exit with calls to e.g. mcount() (pre > inlining) > Simplify the CFG > Dominator Tree Construction > SROA > Early CSE > Lower 'expect' Intrinsics > > (My Run): opt in.bc -o out.bc -debug-pass=Executions -tti -tbaa > -scoped-noalias -assumption-cache-tracker -targetlibinfo -verify > -ee-instrument -simplifycfg -domtree -sroa -early-cse -lower-expect > > Pass Arguments: * -targetlibinfo* -tti *-targetpassconfig* -tbaa > -scoped-noalias -assumption-cache-tracker -verify -ee-instrument > -simplifycfg -domtree -sroa -early-cse -lower-expect *-verify > -write-bitcode* > *Target Library Information* > Target Transform Information > Target Pass Configuration > Type-Based Alias Analysis > Scoped NoAlias Alias Analysis > Assumption Cache Tracker > *ModulePass Manager* > FunctionPass Manager > Module Verifier > Instrument function entry/exit with calls to e.g. mcount() (pre > inlining) > Simplify the CFG > Dominator Tree Construction > SROA > Early CSE > Lower 'expect' Intrinsics >-------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20200811/e3c4322b/attachment.html>
Sanjay Patel via llvm-dev
2020-Aug-12 12:12 UTC
[llvm-dev] opt - replicating multiple passes from -O3 -debug-pass=Executions
The pipeline built with -O3 includes non-default options for -simplifycfg when it runs late. I don't know if it is possible to replicate that behavior if you are trying to specify multiple runs of a pass via the command-line options. // Cleanup after loop vectorization, etc. Simplification passes like CVP and // GVN, loop transforms, and others have already run, so it's now better to // convert to more optimized IR using more aggressive simplify CFG options. // The extra sinking transform can create larger basic blocks, so do this // before SLP vectorization. // FIXME: study whether hoisting and/or sinking of common instructions should // be delayed until after SLP vectorizer. MPM.add(createCFGSimplificationPass(SimplifyCFGOptions() .forwardSwitchCondToPhi(true) .convertSwitchToLookupTable(true) .needCanonicalLoops(false) .hoistCommonInsts(true) .sinkCommonInsts(true))); On Tue, Aug 11, 2020 at 1:14 PM Chad Verbowski via llvm-dev < llvm-dev at lists.llvm.org> wrote:> Update: Comparing the -print-before-all and -print-after-all for -O3 and > the run with the flags, I see a difference starting with the 7th (of 8) > "*** IR Dump After Simplify the CFG ***" which I assume is the -simplifycfg > flag. > > Is there any known reason -simplifycfg would behave differently if the > pipeline of passes up to this point are identical (order and their input > and output)? > > Thanks. > > > On Mon, Aug 10, 2020 at 10:42 PM Chad Verbowski <chad at verbowski.com> > wrote: > >> Hello, >> >> I am trying to replicate the output from opt -O3 foo.bc -o foo.opt.bc by >> specifying the individual passes instead of the -O3 flag. >> >> Looking at the passes from opt -O3 foo.bc -o foo.bc >> -debug-pass=Executions it seems there are two passes being run. When I run >> the flags indicated for the two passes specified in the 'Pass Arguments:' >> as two sequential opt processes or a single opt process with the >> concatenated flags I get a different binary result compared to the O3 run. >> (Note I had to remove the -targetpassconfig flag and >> add -spec-exec-only-if-divergent-target to the second pass to get my run to >> match O3's second pass.) >> >> Comparing the -debug-pass=Executions from my runs with the O3 run, it >> seems the first pass in my run has additional 'TargetLibrary Information', >> 'Target Pass Configuration' and the 'Module Pass Manager' entries compared >> to O3 (copied below). My output shows the 'Pass Arguments:' line has >> automatically added -targetpassconfig -verify -writebitcode, and the >> -targetlibinfo flag was moved to the start. >> >> Is there a way I can address these differences to enable replicating the >> -O3 first and second passes using opt flags? >> >> Thanks for considering this, >> >> -Chad >> >> (Opt -O3 first pass) Pass Arguments: -tti -tbaa -scoped-noalias >> -assumption-cache-tracker -targetlibinfo -verify -ee-instrument >> -simplifycfg -domtree -sroa -early-cse -lower-expect >> Target Transform Information >> Type-Based Alias Analysis >> Scoped NoAlias Alias Analysis >> Assumption Cache Tracker >> Target Library Information >> FunctionPass Manager >> Module Verifier >> Instrument function entry/exit with calls to e.g. mcount() (pre >> inlining) >> Simplify the CFG >> Dominator Tree Construction >> SROA >> Early CSE >> Lower 'expect' Intrinsics >> >> (My Run): opt in.bc -o out.bc -debug-pass=Executions -tti -tbaa >> -scoped-noalias -assumption-cache-tracker -targetlibinfo -verify >> -ee-instrument -simplifycfg -domtree -sroa -early-cse -lower-expect >> >> Pass Arguments: * -targetlibinfo* -tti *-targetpassconfig* -tbaa >> -scoped-noalias -assumption-cache-tracker -verify -ee-instrument >> -simplifycfg -domtree -sroa -early-cse -lower-expect *-verify >> -write-bitcode* >> *Target Library Information* >> Target Transform Information >> Target Pass Configuration >> Type-Based Alias Analysis >> Scoped NoAlias Alias Analysis >> Assumption Cache Tracker >> *ModulePass Manager* >> FunctionPass Manager >> Module Verifier >> Instrument function entry/exit with calls to e.g. mcount() (pre >> inlining) >> Simplify the CFG >> Dominator Tree Construction >> SROA >> Early CSE >> Lower 'expect' Intrinsics >> > _______________________________________________ > LLVM Developers mailing list > llvm-dev at lists.llvm.org > https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev >-------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20200812/44e5b373/attachment.html>