Jingu Kang via llvm-dev
2021-Jun-21 17:54 UTC
[llvm-dev] Enabling Loop Distribution Pass as default in the pipeline of new pass manager
The compile time data is as below. There could be a bit noise but it looks there is no big compile time regression.>From llvm-test-suiteMetric: compile_time Program results_base results_loop_dist diff test-suite...arks/VersaBench/dbms/dbms.test 0.94 0.95 1.6% test-suite...s/MallocBench/cfrac/cfrac.test 0.89 0.90 1.5% test-suite...ks/Prolangs-C/gnugo/gnugo.test 0.72 0.73 1.4% test-suite...yApps-C++/PENNANT/PENNANT.test 8.65 8.75 1.2% test-suite...marks/Ptrdist/yacr2/yacr2.test 0.84 0.85 1.1% test-suite.../Builtins/Int128/Builtins.test 0.86 0.87 1.0% test-suite...s/ASC_Sequoia/AMGmk/AMGmk.test 0.69 0.70 1.0% test-suite...decode/alacconvert-decode.test 1.16 1.17 0.9% test-suite...encode/alacconvert-encode.test 1.16 1.17 0.9% test-suite...peg2/mpeg2dec/mpeg2decode.test 1.71 1.72 0.9% test-suite.../Applications/spiff/spiff.test 0.88 0.89 0.9% test-suite...terpolation/Interpolation.test 0.96 0.97 0.9% test-suite...chmarks/MallocBench/gs/gs.test 4.58 4.62 0.9% test-suite...-C++/stepanov_abstraction.test 0.69 0.70 0.8% test-suite...marks/7zip/7zip-benchmark.test 52.35 52.74 0.7% Geomean difference nan% results_base results_loop_dist diff count 117.000000 118.000000 117.000000 mean 4.636126 4.616575 0.002171 std 7.725991 7.737663 0.006310 min 0.607300 0.602200 -0.041930 25% 1.345700 1.313650 -0.001577 50% 1.887000 1.888800 0.002463 75% 4.340800 4.343275 0.005754 max 52.351200 52.736000 0.015861>From SPEC2017benchmarks baseline enable-loop-distribute diff (seconds) 500.perlbench_r 00:01:06 00:01:04 -2 502.gcc_r 00:05:24 00:05:25 1 505.mcf_r 00:00:02 00:00:02 0 520.omnetpp_r 00:00:58 00:00:58 0 523.xalancbmk_r 00:02:30 00:02:30 0 525.x264_r 00:00:32 00:00:31 -1 531.deepsjeng_r 00:00:04 00:00:04 0 541.leela_r 00:00:06 00:00:06 0 557.xz_r 00:00:05 00:00:05 0 999.specrand_ir 00:00:01 00:00:00 1>From SPEC2006 (number is seconds)benchmarks baseline enable-loop-distribute diff (seconds) 400.perlbench 00:00:29 00:00:29 0 401.bzip2 00:00:04 00:00:03 -1 403.gcc 00:01:28 00:01:26 -2 429.mcf 00:00:01 00:00:01 0 445.gobmk 00:00:24 00:00:24 0 456.hmmer 00:00:06 00:00:06 0 458.sjeng 00:00:03 00:00:03 0 462.libquantum 00:00:03 00:00:02 -1 464.h264ref 00:00:29 00:00:29 0 471.omnetpp 00:00:23 00:00:24 1 473.astar 00:00:02 00:00:02 0 483.xalancbmk 00:02:07 00:02:06 -1 999.specrand 00:00:01 00:00:01 0 Thanks JinGu Kang From: llvm-dev <llvm-dev-bounces at lists.llvm.org> On Behalf Of Sjoerd Meijer via llvm-dev Sent: 21 June 2021 14:36 To: Jingu Kang <Jingu.Kang at arm.com>; Michael Kruse <llvmdev at meinersbur.de>; Kyrylo Tkachov <Kyrylo.Tkachov at arm.com> Cc: llvm-dev at lists.llvm.org Subject: Re: [llvm-dev] Enabling Loop Distribution Pass as default in the pipeline of new pass manager> Based on this data, I think we could say the pass is usually beneficial without causing major regression.I think we need to look at compile-times too before we can draw that conclusion, i.e. we need to justify it's worth spending extra compile-time for optimising a few cases. Hopefully loop distribution is a cheap pass to run (also when it is running but not triggering), but that's something that needs to be checked I think. ________________________________ From: Jingu Kang <Jingu.Kang at arm.com<mailto:Jingu.Kang at arm.com>> Sent: 21 June 2021 14:27 To: Michael Kruse <llvmdev at meinersbur.de<mailto:llvmdev at meinersbur.de>>; Kyrylo Tkachov <Kyrylo.Tkachov at arm.com<mailto:Kyrylo.Tkachov at arm.com>>; Sjoerd Meijer <Sjoerd.Meijer at arm.com<mailto:Sjoerd.Meijer at arm.com>> Cc: llvm-dev at lists.llvm.org<mailto:llvm-dev at lists.llvm.org> <llvm-dev at lists.llvm.org<mailto:llvm-dev at lists.llvm.org>> Subject: RE: [llvm-dev] Enabling Loop Distribution Pass as default in the pipeline of new pass manager For considering the LoopDistribute pass as a canonicalization with the profitability heuristic of LoopFuse pass, it looks the LoopFuse pass does not also have proper profitability function. If possible, I would like to enable the LoopDistribute pass based on the performance data. As you can see on the previous email, the Geomean difference from llvm-test-suite is -0.0%. From spec benchmarks, we can see 43% performance improvement on 456.hmmer of SPEC2006. Based on this data, I think we could say the pass is usually beneficial without causing major regression. How do you think about it? Thanks JinGu Kang> -----Original Message----- > From: Jingu Kang > Sent: 18 June 2021 13:13 > To: Michael Kruse <llvmdev at meinersbur.de<mailto:llvmdev at meinersbur.de>>; Kyrylo Tkachov > <Kyrylo.Tkachov at arm.com<mailto:Kyrylo.Tkachov at arm.com>>; Sjoerd Meijer <Sjoerd.Meijer at arm.com<mailto:Sjoerd.Meijer at arm.com>> > Cc: llvm-dev at lists.llvm.org<mailto:llvm-dev at lists.llvm.org> > Subject: RE: [llvm-dev] Enabling Loop Distribution Pass as default in the pipeline > of new pass manager > > I appreciate your replies. I have seen below performance data. > > For AArch64, the performance data from llvm-test-suite is as below. > > Metric: exec_time > > Program results_base results_loop_dist diff > test-suite...ications/JM/lencod/lencod.test 3.95 4.29 8.8% > test-suite...emCmp<5, GreaterThanZero, Mid> 1456.09 1574.29 8.1% > test-suite...st:BM_BAND_LIN_EQ_LAMBDA/44217 22.83 24.50 7.3% > test-suite....test:BM_BAND_LIN_EQ_RAW/44217 23.00 24.17 5.1% > test-suite...st:BM_INT_PREDICT_LAMBDA/44217 589.54 616.70 4.6% > test-suite...t:BENCHMARK_asin_novec_double_ 330.25 342.17 3.6% > test-suite...ow-dbl/GlobalDataFlow-dbl.test 2.58 2.67 3.3% > test-suite...da.test:BM_PIC_2D_LAMBDA/44217 781.30 806.36 3.2% > test-suite...est:BM_ENERGY_CALC_LAMBDA/5001 63.02 64.93 3.0% > test-suite...gebra/kernels/syr2k/syr2k.test 6.53 6.73 3.0% > test-suite...t/StatementReordering-flt.test 2.33 2.40 2.8% > test-suite...sCRaw.test:BM_PIC_2D_RAW/44217 789.90 810.05 2.6% > test-suite...s/gramschmidt/gramschmidt.test 1.44 1.48 2.5% > test-suite...Raw.test:BM_HYDRO_1D_RAW/44217 38.42 39.37 2.5% > test-suite....test:BM_INT_PREDICT_RAW/44217 597.73 612.34 2.4% > Geomean difference -0.0% > results_base results_loop_dist diff > count 584.000000 584.000000 584.000000 > mean 2761.681991 2759.451499 -0.000020 > std 30145.555650 30124.858004 0.011093 > min 0.608782 0.608729 -0.116286 > 25% 3.125425 3.106625 -0.000461 > 50% 130.212207 130.582658 0.000004 > 75% 602.708659 612.931769 0.000438 > max 511340.880000 511059.980000 0.087630 > > For AArch64, the performance data from SPEC benchmark is as below. > > SPEC2006 > Benchmark Improvement(%) > 400.perlbench -1.786911228 > 401.bzip2 -3.174199894 > 403.gcc 0.717990522 > 429.mcf 2.053027806 > 445.gobmk 0.775388165 > 456.hmmer 43.39308377 > 458.sjeng 0.133933093 > 462.libquantum 4.647923489 > 464.h264ref -0.059568786 > 471.omnetpp 1.352515266 > 473.astar 0.362752409 > 483.xalancbmk 0.746580249 > > SPEC2017 > Benchmark Improvement(%) > 500.perlbench_r 0.415424516 > 502.gcc_r -0.112915812 > 505.mcf_r 0.238633706 > 520.omnetpp_r 0.114830748 > 523.xalancbmk_r 0.460107636 > 525.x264_r -0.401915964 > 531.deepsjeng_r 0.010064227 > 541.leela_r 0.394797504 > 557.xz_r 0.111781366 > > Thanks > JinGu Kang > > > -----Original Message----- > > From: Michael Kruse <llvmdev at meinersbur.de<mailto:llvmdev at meinersbur.de>> > > Sent: 17 June 2021 19:13 > > To: Jingu Kang <Jingu.Kang at arm.com<mailto:Jingu.Kang at arm.com>> > > Cc: llvm-dev at lists.llvm.org<mailto:llvm-dev at lists.llvm.org> > > Subject: Re: [llvm-dev] Enabling Loop Distribution Pass as default in > > the pipeline of new pass manager > > > > The LoopDistribute pass doesn't do anything unless it sees > > llvm.loop.distribute.enable (`#pragma clang loop distribute(enable)`) > > because it does not have a profitability heuristic. It cannot say > > whether loop distribution is good for performance or not. What makes > > it improve hmmer is that the distributed loops can be vectoried. > > However, LoopDistribute is located before the vectorizer and cannot > > say in advance whether a distributed loop will be vectorized or not. > > If not, then it potentially only increased loop overhead. > > > > To make -enable-loop-distribute on by default would mean that we could > > consider loop distribution to be usually beneficial without causing > > major regressions. We need a lot more data to support that conclusion. > > > > Alternatively, we could consider loop-distribution a canonicalization. > > A later LoopFuse would do the profitability heuristic to re-fuse loops > > again if loop distribution did not gain anything. > > > > Michael-------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20210621/45330e07/attachment.html>
Michael Kruse via llvm-dev
2021-Jun-21 18:12 UTC
[llvm-dev] Enabling Loop Distribution Pass as default in the pipeline of new pass manager
[adding nikc to CC] @nikc Would you consider this amount of regression acceptable? Am Mo., 21. Juni 2021 um 12:54 Uhr schrieb Jingu Kang <Jingu.Kang at arm.com>:> The compile time data is as below. There could be a bit noise but it looks > there is no big compile time regression. > > > > From llvm-test-suite > > > > Metric: compile_time > > > > Program results_base > results_loop_dist diff > > test-suite...arks/VersaBench/dbms/dbms.test 0.94 > 0.95 1.6% > > test-suite...s/MallocBench/cfrac/cfrac.test 0.89 > 0.90 1.5% > > test-suite...ks/Prolangs-C/gnugo/gnugo.test 0.72 > 0.73 1.4% > > test-suite...yApps-C++/PENNANT/PENNANT.test 8.65 > 8.75 1.2% > > test-suite...marks/Ptrdist/yacr2/yacr2.test 0.84 > 0.85 1.1% > > test-suite.../Builtins/Int128/Builtins.test 0.86 > 0.87 1.0% > > test-suite...s/ASC_Sequoia/AMGmk/AMGmk.test 0.69 > 0.70 1.0% > > test-suite...decode/alacconvert-decode.test 1.16 > 1.17 0.9% > > test-suite...encode/alacconvert-encode.test 1.16 > 1.17 0.9% > > test-suite...peg2/mpeg2dec/mpeg2decode.test 1.71 > 1.72 0.9% > > test-suite.../Applications/spiff/spiff.test 0.88 > 0.89 0.9% > > test-suite...terpolation/Interpolation.test 0.96 > 0.97 0.9% > > test-suite...chmarks/MallocBench/gs/gs.test 4.58 > 4.62 0.9% > > test-suite...-C++/stepanov_abstraction.test 0.69 > 0.70 0.8% > > test-suite...marks/7zip/7zip-benchmark.test 52.35 > 52.74 0.7% > > Geomean difference > nan% > > results_base results_loop_dist diff > > count 117.000000 118.000000 117.000000 > > mean 4.636126 4.616575 0.002171 > > std 7.725991 7.737663 0.006310 > > min 0.607300 0.602200 -0.041930 > > 25% 1.345700 1.313650 -0.001577 > > 50% 1.887000 1.888800 0.002463 > > 75% 4.340800 4.343275 0.005754 > > max 52.351200 52.736000 0.015861 > > > > From SPEC2017 > > benchmarks > > baseline > > enable-loop-distribute > > diff (seconds) > > 500.perlbench_r > > 00:01:06 > > 00:01:04 > > -2 > > 502.gcc_r > > 00:05:24 > > 00:05:25 > > 1 > > 505.mcf_r > > 00:00:02 > > 00:00:02 > > 0 > > 520.omnetpp_r > > 00:00:58 > > 00:00:58 > > 0 > > 523.xalancbmk_r > > 00:02:30 > > 00:02:30 > > 0 > > 525.x264_r > > 00:00:32 > > 00:00:31 > > -1 > > 531.deepsjeng_r > > 00:00:04 > > 00:00:04 > > 0 > > 541.leela_r > > 00:00:06 > > 00:00:06 > > 0 > > 557.xz_r > > 00:00:05 > > 00:00:05 > > 0 > > 999.specrand_ir > > 00:00:01 > > 00:00:00 > > 1 > > > > From SPEC2006 (number is seconds) > > benchmarks > > baseline > > enable-loop-distribute > > diff (seconds) > > 400.perlbench > > 00:00:29 > > 00:00:29 > > 0 > > 401.bzip2 > > 00:00:04 > > 00:00:03 > > -1 > > 403.gcc > > 00:01:28 > > 00:01:26 > > -2 > > 429.mcf > > 00:00:01 > > 00:00:01 > > 0 > > 445.gobmk > > 00:00:24 > > 00:00:24 > > 0 > > 456.hmmer > > 00:00:06 > > 00:00:06 > > 0 > > 458.sjeng > > 00:00:03 > > 00:00:03 > > 0 > > 462.libquantum > > 00:00:03 > > 00:00:02 > > -1 > > 464.h264ref > > 00:00:29 > > 00:00:29 > > 0 > > 471.omnetpp > > 00:00:23 > > 00:00:24 > > 1 > > 473.astar > > 00:00:02 > > 00:00:02 > > 0 > > 483.xalancbmk > > 00:02:07 > > 00:02:06 > > -1 > > 999.specrand > > 00:00:01 > > 00:00:01 > > 0 > > > > Thanks > > JinGu Kang > > > > *From:* llvm-dev <llvm-dev-bounces at lists.llvm.org> *On Behalf Of *Sjoerd > Meijer via llvm-dev > *Sent:* 21 June 2021 14:36 > *To:* Jingu Kang <Jingu.Kang at arm.com>; Michael Kruse < > llvmdev at meinersbur.de>; Kyrylo Tkachov <Kyrylo.Tkachov at arm.com> > *Cc:* llvm-dev at lists.llvm.org > *Subject:* Re: [llvm-dev] Enabling Loop Distribution Pass as default in > the pipeline of new pass manager > > > > > Based on this data, I think we could say the pass is usually beneficial > without causing major regression. > > > > I think we need to look at compile-times too before we can draw that > conclusion, i.e. we need to justify it's worth spending extra compile-time > for optimising a few cases. Hopefully loop distribution is a cheap pass to > run (also when it is running but not triggering), but that's something that > needs to be checked I think. > ------------------------------ > > *From:* Jingu Kang <Jingu.Kang at arm.com> > *Sent:* 21 June 2021 14:27 > *To:* Michael Kruse <llvmdev at meinersbur.de>; Kyrylo Tkachov < > Kyrylo.Tkachov at arm.com>; Sjoerd Meijer <Sjoerd.Meijer at arm.com> > *Cc:* llvm-dev at lists.llvm.org <llvm-dev at lists.llvm.org> > *Subject:* RE: [llvm-dev] Enabling Loop Distribution Pass as default in > the pipeline of new pass manager > > > > For considering the LoopDistribute pass as a canonicalization with the > profitability heuristic of LoopFuse pass, it looks the LoopFuse pass does > not also have proper profitability function. > > If possible, I would like to enable the LoopDistribute pass based on the > performance data. > > As you can see on the previous email, the Geomean difference from > llvm-test-suite is -0.0%. From spec benchmarks, we can see 43% performance > improvement on 456.hmmer of SPEC2006. Based on this data, I think we could > say the pass is usually beneficial without causing major regression. > > How do you think about it? > > Thanks > JinGu Kang > > > -----Original Message----- > > From: Jingu Kang > > Sent: 18 June 2021 13:13 > > To: Michael Kruse <llvmdev at meinersbur.de>; Kyrylo Tkachov > > <Kyrylo.Tkachov at arm.com>; Sjoerd Meijer <Sjoerd.Meijer at arm.com> > > Cc: llvm-dev at lists.llvm.org > > Subject: RE: [llvm-dev] Enabling Loop Distribution Pass as default in > the pipeline > > of new pass manager > > > > I appreciate your replies. I have seen below performance data. > > > > For AArch64, the performance data from llvm-test-suite is as below. > > > > Metric: exec_time > > > > Program results_base > results_loop_dist diff > > test-suite...ications/JM/lencod/lencod.test 3.95 > 4.29 8.8% > > test-suite...emCmp<5, GreaterThanZero, Mid> 1456.09 > 1574.29 8.1% > > test-suite...st:BM_BAND_LIN_EQ_LAMBDA/44217 22.83 > 24.50 7.3% > > test-suite....test:BM_BAND_LIN_EQ_RAW/44217 23.00 > 24.17 5.1% > > test-suite...st:BM_INT_PREDICT_LAMBDA/44217 589.54 > 616.70 4.6% > > test-suite...t:BENCHMARK_asin_novec_double_ 330.25 > 342.17 3.6% > > test-suite...ow-dbl/GlobalDataFlow-dbl.test 2.58 > 2.67 3.3% > > test-suite...da.test:BM_PIC_2D_LAMBDA/44217 781.30 > 806.36 3.2% > > test-suite...est:BM_ENERGY_CALC_LAMBDA/5001 63.02 > 64.93 3.0% > > test-suite...gebra/kernels/syr2k/syr2k.test 6.53 > 6.73 3.0% > > test-suite...t/StatementReordering-flt.test 2.33 > 2.40 2.8% > > test-suite...sCRaw.test:BM_PIC_2D_RAW/44217 789.90 > 810.05 2.6% > > test-suite...s/gramschmidt/gramschmidt.test 1.44 > 1.48 2.5% > > test-suite...Raw.test:BM_HYDRO_1D_RAW/44217 38.42 > 39.37 2.5% > > test-suite....test:BM_INT_PREDICT_RAW/44217 597.73 > 612.34 2.4% > > Geomean > difference -0.0% > > results_base results_loop_dist diff > > count 584.000000 584.000000 584.000000 > > mean 2761.681991 2759.451499 -0.000020 > > std 30145.555650 30124.858004 0.011093 > > min 0.608782 0.608729 -0.116286 > > 25% 3.125425 3.106625 -0.000461 > > 50% 130.212207 130.582658 0.000004 > > 75% 602.708659 612.931769 0.000438 > > max 511340.880000 511059.980000 0.087630 > > > > For AArch64, the performance data from SPEC benchmark is as below. > > > > SPEC2006 > > Benchmark Improvement(%) > > 400.perlbench -1.786911228 > > 401.bzip2 -3.174199894 > > 403.gcc 0.717990522 > > 429.mcf 2.053027806 > > 445.gobmk 0.775388165 > > 456.hmmer 43.39308377 > > 458.sjeng 0.133933093 > > 462.libquantum 4.647923489 > > 464.h264ref -0.059568786 > > 471.omnetpp 1.352515266 > > 473.astar 0.362752409 > > 483.xalancbmk 0.746580249 > > > > SPEC2017 > > Benchmark Improvement(%) > > 500.perlbench_r 0.415424516 > > 502.gcc_r -0.112915812 > > 505.mcf_r 0.238633706 > > 520.omnetpp_r 0.114830748 > > 523.xalancbmk_r 0.460107636 > > 525.x264_r -0.401915964 > > 531.deepsjeng_r 0.010064227 > > 541.leela_r 0.394797504 > > 557.xz_r 0.111781366 > > > > Thanks > > JinGu Kang > > > > > -----Original Message----- > > > From: Michael Kruse <llvmdev at meinersbur.de> > > > Sent: 17 June 2021 19:13 > > > To: Jingu Kang <Jingu.Kang at arm.com> > > > Cc: llvm-dev at lists.llvm.org > > > Subject: Re: [llvm-dev] Enabling Loop Distribution Pass as default in > > > the pipeline of new pass manager > > > > > > The LoopDistribute pass doesn't do anything unless it sees > > > llvm.loop.distribute.enable (`#pragma clang loop distribute(enable)`) > > > because it does not have a profitability heuristic. It cannot say > > > whether loop distribution is good for performance or not. What makes > > > it improve hmmer is that the distributed loops can be vectoried. > > > However, LoopDistribute is located before the vectorizer and cannot > > > say in advance whether a distributed loop will be vectorized or not. > > > If not, then it potentially only increased loop overhead. > > > > > > To make -enable-loop-distribute on by default would mean that we could > > > consider loop distribution to be usually beneficial without causing > > > major regressions. We need a lot more data to support that conclusion. > > > > > > Alternatively, we could consider loop-distribution a canonicalization. > > > A later LoopFuse would do the profitability heuristic to re-fuse loops > > > again if loop distribution did not gain anything. > > > > > > Michael >-------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20210621/4f8dce72/attachment.html>