[all-commits] [llvm/llvm-project] b5e208: [DSE] Support looking through memory phis at end o...
Florian Hahn via All-commits
all-commits at lists.llvm.org
Tue Aug 30 05:28:32 PDT 2022
Branch: refs/heads/main
Home: https://github.com/llvm/llvm-project
Commit: b5e208fcbaa6c76a33a96e230e9df2121bed2a10
https://github.com/llvm/llvm-project/commit/b5e208fcbaa6c76a33a96e230e9df2121bed2a10
Author: Florian Hahn <flo at fhahn.com>
Date: 2022-08-30 (Tue, 30 Aug 2022)
Changed paths:
M llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp
M llvm/test/Transforms/DeadStoreElimination/multiblock-memintrinsics.ll
M llvm/test/Transforms/DeadStoreElimination/phi-translation.ll
M llvm/test/Transforms/MemCpyOpt/memcpy.ll
Log Message:
-----------
[DSE] Support looking through memory phis at end of function.
Update isWriteAtEndOfFunction to look through MemoryPhis. The reason
MemoryPhis were skipped so far was the known AliasAnalysis issue with it
missing loop-carried dependences.
This problem is already addressed in other parts of the code by skipping
MemoryDefs that may be in difference loops. I think the same logic can
be applied here.
This can have a substantial impact on the number of stores removed in
some cases. For MultiSource/SPEC2006/SPEC2017 with -O3:
```
Metric: dse.NumFastStores
Program dse.NumFastStores
base patch diff
External/S...CINT2017rate/557.xz_r/557.xz_r 14.00 45.00 221.4%
External/S...te/538.imagick_r/538.imagick_r 439.00 1267.00 188.6%
MultiSourc...e/Applications/SIBsim4/SIBsim4 6.00 15.00 150.0%
MultiSourc...Prolangs-C/simulator/simulator 3.00 7.00 133.3%
MultiSource/Applications/siod/siod 3.00 7.00 133.3%
MultiSourc...arks/FreeBench/distray/distray 6.00 9.00 50.0%
MultiSourc...e/Applications/obsequi/Obsequi 22.00 30.00 36.4%
MultiSource/Benchmarks/Ptrdist/bc/bc 23.00 28.00 21.7%
External/S...NT2017rate/502.gcc_r/502.gcc_r 1258.00 1512.00 20.2%
External/S...te/520.omnetpp_r/520.omnetpp_r 954.00 1143.00 19.8%
External/S...rate/510.parest_r/510.parest_r 5961.00 7122.00 19.5%
External/S...C/CINT2006/445.gobmk/445.gobmk 47.00 56.00 19.1%
External/S...00.perlbench_r/500.perlbench_r 241.00 286.00 18.7%
External/S...NT2006/471.omnetpp/471.omnetpp 36.00 42.00 16.7%
External/S...06/400.perlbench/400.perlbench 183.00 210.00 14.8%
MultiSource/Applications/SPASS/SPASS 72.00 81.00 12.5%
External/S...17rate/541.leela_r/541.leela_r 72.00 80.00 11.1%
External/SPEC/CINT2006/403.gcc/403.gcc 585.00 642.00 9.7%
MultiSourc...e/Applications/sqlite3/sqlite3 120.00 131.00 9.2%
MultiSourc...Applications/hexxagon/hexxagon 11.00 12.00 9.1%
External/S.../CFP2006/453.povray/453.povray 566.00 615.00 8.7%
External/S...rate/511.povray_r/511.povray_r 578.00 627.00 8.5%
External/S...FP2006/482.sphinx3/482.sphinx3 12.00 13.00 8.3%
MultiSource/Applications/oggenc/oggenc 130.00 140.00 7.7%
MultiSourc...e/Applications/ClamAV/clamscan 250.00 268.00 7.2%
MultiSourc.../mediabench/jpeg/jpeg-6a/cjpeg 19.00 20.00 5.3%
MultiSourc...ch/consumer-jpeg/consumer-jpeg 19.00 20.00 5.3%
External/S...te/526.blender_r/526.blender_r 3747.00 3928.00 4.8%
MultiSourc...OE-ProxyApps-C++/miniFE/miniFE 104.00 108.00 3.8%
MultiSourc...ch/consumer-lame/consumer-lame 54.00 56.00 3.7%
MultiSource/Benchmarks/Bullet/bullet 1222.00 1264.00 3.4%
MultiSourc...nchmarks/tramp3d-v4/tramp3d-v4 973.00 1005.00 3.3%
External/S.../CFP2006/447.dealII/447.dealII 2699.00 2780.00 3.0%
External/S...06/483.xalancbmk/483.xalancbmk 788.00 810.00 2.8%
External/S.../CFP2006/450.soplex/450.soplex 180.00 185.00 2.8%
MultiSourc.../DOE-ProxyApps-C++/CLAMR/CLAMR 338.00 345.00 2.1%
MultiSourc...Benchmarks/7zip/7zip-benchmark 685.00 699.00 2.0%
External/S...FP2017rate/544.nab_r/544.nab_r 158.00 160.00 1.3%
MultiSourc...sumer-typeset/consumer-typeset 772.00 781.00 1.2%
External/S...2017rate/525.x264_r/525.x264_r 410.00 414.00 1.0%
External/S...23.xalancbmk_r/523.xalancbmk_r 998.00 1002.00 0.4%
```
Compile-time is almost neutral:
https://llvm-compile-time-tracker.com/compare.php?from=b3125ad3d60531a97eea20009cc9629a87755862&to=84007eee59004f43464eda7f5ba8263ed5158df8&stat=instructions
NewPM-O3: +0.03%
NewPM-ReleaseThinLTO: -0.01%
NewPM-ReleaseLTO-g: +0.03%
Reviewed By: asbirlea
Differential Revision: https://reviews.llvm.org/D132365
More information about the All-commits
mailing list