Florian Hahn b82f80057d [DSE] Use walker to skip noalias stores between current & clobber def. ... Instead of getting the defining access we should be able to use getClobberingMemoryAccess to skip non-aliasing MemoryDefs. No additional checks should be needed, because we only remove the starting def if it matches the defining access of the load. All we need to worry about is that there are no (may)alias stores between the starting def and the load and getClobberingMemoryAccess should guarantee that. Partly fixes PR47887. This improves the number of redundant stores removed in some cases (numbers below for MultiSource, SPEC2000, SPEC2006 on X86 with -flto -O3). Same hash: 226 (filtered out) Remaining: 11 Metric: dse.NumRedundantStores Program base patch1 diff test-suite...:: External/Povray/povray.test 1.00 5.00 400.0% test-suite...chmarks/MallocBench/gs/gs.test 1.00 3.00 200.0% test-suite...0/253.perlbmk/253.perlbmk.test 21.00 37.00 76.2% test-suite...0.perlbench/400.perlbench.test 24.00 37.00 54.2% test-suite.../Applications/SPASS/SPASS.test 3.00 4.00 33.3% test-suite...006/453.povray/453.povray.test 15.00 18.00 20.0% test-suite...T2006/445.gobmk/445.gobmk.test 27.00 29.00 7.4% test-suite.../CINT2006/403.gcc/403.gcc.test 136.00 137.00 0.7% test-suite.../CINT2000/176.gcc/176.gcc.test 6.00 6.00 0.0% test-suite.../Benchmarks/Bullet/bullet.test NaN 3.00 nan% test-suite.../Benchmarks/Ptrdist/bc/bc.test NaN 1.00 nan% Reviewed By: asbirlea Differential Revision: https://reviews.llvm.org/D89647		2020-10-28 11:01:25 +00:00
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MSSA	[DSE] Use walker to skip noalias stores between current & clobber def.	2020-10-28 11:01:25 +00:00
MemDepAnalysis	[IR] Make nosync, nofree and willreturn default for intrinsics.	2020-10-20 11:57:19 +02:00
masked-dead-store.ll	[DSE] Make sure that DSE+MSSA can handle masked stores	2020-09-11 10:00:21 -05:00