Amara Emerson via llvm-dev
2019-Apr-16 19:10 UTC
[llvm-dev] Interprocedural DSE for -ftrivial-auto-var-init
Can you post numbers for how many stores get eliminated from CTMark?> On Apr 16, 2019, at 11:45 AM, Vitaly Buka <vitalybuka at google.com> wrote: > > I tried -Os and effect of new approach significantly increases. > I run regular DSE and immediately myDSE. With -Os myDSE removes more than 50% of DSE number. > Which is expected as -Os inlines less and regular DSE can't remove over function call. > > On Tue, Apr 16, 2019 at 7:11 AM Alexander Potapenko <glider at google.com <mailto:glider at google.com>> wrote: > On Mon, Apr 15, 2019 at 11:02 PM Amara Emerson via llvm-dev > <llvm-dev at lists.llvm.org <mailto:llvm-dev at lists.llvm.org>> wrote: > > > > > > > On Apr 15, 2019, at 1:51 PM, Vitaly Buka via llvm-dev <llvm-dev at lists.llvm.org <mailto:llvm-dev at lists.llvm.org>> wrote: > > > > > > Hi JF, > > > > > > I've heard that you are interested DSE improvements and maybe we need to be in sync. > > > So far I experimented with following DSE improvements: > > > > > > * Cross-block DSE, it eliminates additional 7% stores comparing to existing DSE. But it's not visible on benchmarks. > > I take it you couldn’t see any runtime impact? If there’s code size improvements that could also be useful, CTMark in the llvm test suite is a useful subset of benchmarks to check this on (as a baseline use -Os to compare code size). > > > > Thanks, > > Amara > > > > > > * Cross-block + Interprocedural analysis to annotate each function argument with: > > > - can read before write > > > - will always write > > > This annotations gets me 20% stores deleted additional to the current DSE. > I believe we can only benefit from removing extra stores. > Hot functions in existing benchmarks are probably optimized good > enough already, but speeding up the long tail is also important. > Also, at least the repro in > https://bugs.llvm.org/show_bug.cgi?id=40527 <https://bugs.llvm.org/show_bug.cgi?id=40527> has been extracted from a > real kernel benchmark (hackbench), where this extra store costed us > 0.45% > > > > This is on LLVM codebase with -ftrivial-auto-var-init=patter. > > > > > > As-is it's less than I expected, so I would like to find good benchmark to decide if we should work to make production code from my experiment. > > > > > > So now I am also planing to try to extend that to whole program analysis. > > > I will cleanup my code and upload this during this weak, if anyone wants to try. > > > > > > Vitaly. > > > _______________________________________________ > > > LLVM Developers mailing list > > > llvm-dev at lists.llvm.org <mailto:llvm-dev at lists.llvm.org> > > > https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev <https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev> > > > > _______________________________________________ > > LLVM Developers mailing list > > llvm-dev at lists.llvm.org <mailto:llvm-dev at lists.llvm.org> > > https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev <https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev> > > > > -- > Alexander Potapenko > Software Engineer > > Google Germany GmbH > Erika-Mann-Straße, 33 > 80636 München > > Geschäftsführer: Paul Manicle, Halimah DeLaine Prado > Registergericht und -nummer: Hamburg, HRB 86891 > Sitz der Gesellschaft: Hamburg-------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20190416/875f6cc0/attachment.html>
Vitaly Buka via llvm-dev
2019-May-11 03:59 UTC
[llvm-dev] Interprocedural DSE for -ftrivial-auto-var-init
Sorry for delay, I was busy with other stuff. CTMark results. dse is the current DSE. dsem is my experimental module level DSE. dsem runs after dse, so it's additionally deleted stores. -O3 dse - Number of stores deleted 3033 dsem - Number of deleted writes 3148 -O3 -ftrivial-auto-var-init=pattern dse - Number of stores deleted 5618 dsem - Number of deleted writes 3840 -O3 -flto dse - Number of stores deleted 3985 dsem - Number of deleted writes 3838 -O3 -flto -ftrivial-auto-var-init=pattern dse - Number of stores deleted 6461 dsem - Number of deleted writes 4215 -Os dse - Number of stores deleted 1443 dsem - Number of deleted writes 1517 -Os -ftrivial-auto-var-init=pattern dse - Number of stores deleted 3951 dsem - Number of deleted writes 2259 -Oz dse - Number of stores deleted 1072 dsem - Number of deleted writes 574 -Oz -ftrivial-auto-var-init=pattern dse - Number of stores deleted 3420 dsem - Number of deleted writes 1637 *From: *Amara Emerson <aemerson at apple.com> *Date: *Tue, Apr 16, 2019 at 12:10 PM *To: *Vitaly Buka *Cc: *Alexander Potapenko, llvm-dev, Peter Collingbourne Can you post numbers for how many stores get eliminated from CTMark?> > On Apr 16, 2019, at 11:45 AM, Vitaly Buka <vitalybuka at google.com> wrote: > > I tried -Os and effect of new approach significantly increases. > I run regular DSE and immediately myDSE. With -Os myDSE removes more than > 50% of DSE number. > Which is expected as -Os inlines less and regular DSE can't remove over > function call. > > On Tue, Apr 16, 2019 at 7:11 AM Alexander Potapenko <glider at google.com> > wrote: > >> On Mon, Apr 15, 2019 at 11:02 PM Amara Emerson via llvm-dev >> <llvm-dev at lists.llvm.org> wrote: >> > >> > >> > > On Apr 15, 2019, at 1:51 PM, Vitaly Buka via llvm-dev < >> llvm-dev at lists.llvm.org> wrote: >> > > >> > > Hi JF, >> > > >> > > I've heard that you are interested DSE improvements and maybe we >> need to be in sync. >> > > So far I experimented with following DSE improvements: >> > > >> > > * Cross-block DSE, it eliminates additional 7% stores comparing to >> existing DSE. But it's not visible on benchmarks. >> > I take it you couldn’t see any runtime impact? If there’s code size >> improvements that could also be useful, CTMark in the llvm test suite is a >> useful subset of benchmarks to check this on (as a baseline use -Os to >> compare code size). >> > >> > Thanks, >> > Amara >> > > >> > > * Cross-block + Interprocedural analysis to annotate each function >> argument with: >> > > - can read before write >> > > - will always write >> > > This annotations gets me 20% stores deleted additional to the current >> DSE. >> I believe we can only benefit from removing extra stores. >> Hot functions in existing benchmarks are probably optimized good >> enough already, but speeding up the long tail is also important. >> Also, at least the repro in >> https://bugs.llvm.org/show_bug.cgi?id=40527 has been extracted from a >> real kernel benchmark (hackbench), where this extra store costed us >> 0.45% >> >> > > This is on LLVM codebase with -ftrivial-auto-var-init=patter. >> > > >> > > As-is it's less than I expected, so I would like to find good >> benchmark to decide if we should work to make production code from my >> experiment. >> > > >> > > So now I am also planing to try to extend that to whole program >> analysis. >> > > I will cleanup my code and upload this during this weak, if anyone >> wants to try. >> > > >> > > Vitaly. >> > > _______________________________________________ >> > > LLVM Developers mailing list >> > > llvm-dev at lists.llvm.org >> > > https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev >> > >> > _______________________________________________ >> > LLVM Developers mailing list >> > llvm-dev at lists.llvm.org >> > https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev >> >> >> >> -- >> Alexander Potapenko >> Software Engineer >> >> Google Germany GmbH >> Erika-Mann-Straße, 33 >> 80636 München >> >> Geschäftsführer: Paul Manicle, Halimah DeLaine Prado >> Registergericht und -nummer: Hamburg, HRB 86891 >> Sitz der Gesellschaft: Hamburg >> > >-------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20190510/aa252eec/attachment.html>
JF Bastien via llvm-dev
2019-May-13 16:55 UTC
[llvm-dev] Interprocedural DSE for -ftrivial-auto-var-init
> On May 10, 2019, at 8:59 PM, Vitaly Buka via llvm-dev <llvm-dev at lists.llvm.org> wrote: > > Sorry for delay, I was busy with other stuff. > CTMark results. > > dse is the current DSE. > dsem is my experimental module level DSE. > dsem runs after dse, so it's additionally deleted stores. > > -O3 > dse - Number of stores deleted 3033 > dsem - Number of deleted writes 3148 > > -O3 -ftrivial-auto-var-init=pattern > dse - Number of stores deleted 5618 > dsem - Number of deleted writes 3840 > > -O3 -flto > dse - Number of stores deleted 3985 > dsem - Number of deleted writes 3838 > > -O3 -flto -ftrivial-auto-var-init=pattern > dse - Number of stores deleted 6461 > dsem - Number of deleted writes 4215 > > -Os > dse - Number of stores deleted 1443 > dsem - Number of deleted writes 1517 > > -Os -ftrivial-auto-var-init=pattern > dse - Number of stores deleted 3951 > dsem - Number of deleted writes 2259 > > -Oz > dse - Number of stores deleted 1072 > dsem - Number of deleted writes 574 > > -Oz -ftrivial-auto-var-init=pattern > dse - Number of stores deleted 3420 > dsem - Number of deleted writes 1637This looks great! Do you have a patch ready to go?> From: Amara Emerson <aemerson at apple.com <mailto:aemerson at apple.com>> > Date: Tue, Apr 16, 2019 at 12:10 PM > To: Vitaly Buka > Cc: Alexander Potapenko, llvm-dev, Peter Collingbourne > > Can you post numbers for how many stores get eliminated from CTMark? > >> On Apr 16, 2019, at 11:45 AM, Vitaly Buka <vitalybuka at google.com <mailto:vitalybuka at google.com>> wrote: >> >> I tried -Os and effect of new approach significantly increases. >> I run regular DSE and immediately myDSE. With -Os myDSE removes more than 50% of DSE number. >> Which is expected as -Os inlines less and regular DSE can't remove over function call. >> >> On Tue, Apr 16, 2019 at 7:11 AM Alexander Potapenko <glider at google.com <mailto:glider at google.com>> wrote: >> On Mon, Apr 15, 2019 at 11:02 PM Amara Emerson via llvm-dev >> <llvm-dev at lists.llvm.org <mailto:llvm-dev at lists.llvm.org>> wrote: >> > >> > >> > > On Apr 15, 2019, at 1:51 PM, Vitaly Buka via llvm-dev <llvm-dev at lists.llvm.org <mailto:llvm-dev at lists.llvm.org>> wrote: >> > > >> > > Hi JF, >> > > >> > > I've heard that you are interested DSE improvements and maybe we need to be in sync. >> > > So far I experimented with following DSE improvements: >> > > >> > > * Cross-block DSE, it eliminates additional 7% stores comparing to existing DSE. But it's not visible on benchmarks. >> > I take it you couldn’t see any runtime impact? If there’s code size improvements that could also be useful, CTMark in the llvm test suite is a useful subset of benchmarks to check this on (as a baseline use -Os to compare code size). >> > >> > Thanks, >> > Amara >> > > >> > > * Cross-block + Interprocedural analysis to annotate each function argument with: >> > > - can read before write >> > > - will always write >> > > This annotations gets me 20% stores deleted additional to the current DSE. >> I believe we can only benefit from removing extra stores. >> Hot functions in existing benchmarks are probably optimized good >> enough already, but speeding up the long tail is also important. >> Also, at least the repro in >> https://bugs.llvm.org/show_bug.cgi?id=40527 <https://bugs.llvm.org/show_bug.cgi?id=40527> has been extracted from a >> real kernel benchmark (hackbench), where this extra store costed us >> 0.45% >> >> > > This is on LLVM codebase with -ftrivial-auto-var-init=patter. >> > > >> > > As-is it's less than I expected, so I would like to find good benchmark to decide if we should work to make production code from my experiment. >> > > >> > > So now I am also planing to try to extend that to whole program analysis. >> > > I will cleanup my code and upload this during this weak, if anyone wants to try. >> > > >> > > Vitaly. >> > > _______________________________________________ >> > > LLVM Developers mailing list >> > > llvm-dev at lists.llvm.org <mailto:llvm-dev at lists.llvm.org> >> > > https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev <https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev> >> > >> > _______________________________________________ >> > LLVM Developers mailing list >> > llvm-dev at lists.llvm.org <mailto:llvm-dev at lists.llvm.org> >> > https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev <https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev> >> >> >> >> -- >> Alexander Potapenko >> Software Engineer >> >> Google Germany GmbH >> Erika-Mann-Straße, 33 >> 80636 München >> >> Geschäftsführer: Paul Manicle, Halimah DeLaine Prado >> Registergericht und -nummer: Hamburg, HRB 86891 >> Sitz der Gesellschaft: Hamburg > > _______________________________________________ > 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... 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