Florian Hahn 6d82efa764 [SCEV] If Start>=RHS, simplify (Start smin RHS) = RHS for trip counts. ... In some cases, it seems like we can get rid of unnecessary s/umins by using information from the loop guards (unless I am missing something). One place where this seems to be helpful in practice is when computing loop trip counts. This patch just changes howManyGreaterThans for now. Note that this requires a loop for which we can check 'is guarded'. On SPEC2000/SPEC2006/MultiSource, there are some notable changes for some programs in the number of loops unrolled and trip counts computed. ``` Same hash: 179 (filtered out) Remaining: 58 Metric: scalar-evolution.NumTripCountsComputed Program base patch diff test-suite...langs-C/compiler/compiler.test 25.00 31.00 24.0% test-suite.../Applications/SPASS/SPASS.test 2020.00 2323.00 15.0% test-suite...langs-C/allroots/allroots.test 29.00 32.00 10.3% test-suite.../Prolangs-C/loader/loader.test 17.00 18.00 5.9% test-suite...fice-ispell/office-ispell.test 253.00 265.00 4.7% test-suite...006/450.soplex/450.soplex.test 3552.00 3692.00 3.9% test-suite...chmarks/MallocBench/gs/gs.test 453.00 470.00 3.8% test-suite...ngs-C/assembler/assembler.test 29.00 30.00 3.4% test-suite.../Benchmarks/Ptrdist/bc/bc.test 263.00 270.00 2.7% test-suite...rks/FreeBench/pifft/pifft.test 722.00 741.00 2.6% test-suite...count/automotive-bitcount.test 41.00 42.00 2.4% test-suite...0/253.perlbmk/253.perlbmk.test 1417.00 1451.00 2.4% test-suite...000/197.parser/197.parser.test 387.00 396.00 2.3% test-suite...lications/sqlite3/sqlite3.test 1168.00 1189.00 1.8% test-suite...000/255.vortex/255.vortex.test 173.00 176.00 1.7% Metric: loop-unroll.NumUnrolled Program base patch diff test-suite...langs-C/compiler/compiler.test 1.00 3.00 200.0% test-suite.../Applications/SPASS/SPASS.test 134.00 234.00 74.6% test-suite...count/automotive-bitcount.test 3.00 4.00 33.3% test-suite.../Prolangs-C/loader/loader.test 3.00 4.00 33.3% test-suite...langs-C/allroots/allroots.test 3.00 4.00 33.3% test-suite...Source/Benchmarks/sim/sim.test 10.00 12.00 20.0% test-suite...fice-ispell/office-ispell.test 21.00 25.00 19.0% test-suite.../Benchmarks/Ptrdist/bc/bc.test 32.00 38.00 18.8% test-suite...006/450.soplex/450.soplex.test 300.00 352.00 17.3% test-suite...rks/FreeBench/pifft/pifft.test 60.00 69.00 15.0% test-suite...chmarks/MallocBench/gs/gs.test 57.00 63.00 10.5% test-suite...ngs-C/assembler/assembler.test 10.00 11.00 10.0% test-suite...0/253.perlbmk/253.perlbmk.test 145.00 157.00 8.3% test-suite...000/197.parser/197.parser.test 43.00 46.00 7.0% test-suite...TimberWolfMC/timberwolfmc.test 205.00 214.00 4.4% Geomean difference 7.6% ``` Fixes https://bugs.llvm.org/show_bug.cgi?id=46939 Fixes https://bugs.llvm.org/show_bug.cgi?id=46924 on X86. Reviewed By: mkazantsev Differential Revision: https://reviews.llvm.org/D85046		2020-08-03 17:22:42 +01:00
..
ARM
loop-guards.ll
scalar-while.ll	[SCEV] If Start>=RHS, simplify (Start smin RHS) = RHS for trip counts.	2020-08-03 17:22:42 +01:00
sibling-loops.ll
unconditional-latch.ll
unscevable.ll