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| author | Philip Reames <listmail@philipreames.com> | 2019-11-21 09:52:38 -0800 |
|---|---|---|
| committer | Philip Reames <listmail@philipreames.com> | 2019-11-21 09:53:43 -0800 |
| commit | f1a9a83232230e1c848a91270ebe0d4089f0a803 (patch) | |
| tree | abed7593260315c8b7374785ad05cc18eb3c146d /llvm/lib/Analysis | |
| parent | 4dc2fb123dcfe9a97ad6f3a1135053b74efd0bc9 (diff) | |
| download | bcm5719-llvm-f1a9a83232230e1c848a91270ebe0d4089f0a803.tar.gz bcm5719-llvm-f1a9a83232230e1c848a91270ebe0d4089f0a803.zip | |
[SCEV] Be robust against IR generated by simple-loop-unswitch
Simple loop unswitch likes to leave around unsimplified and/or/xors. SCEV today bails out on these idioms which is unfortunate in general, and specifically for the unswitch interaction.
Differential Revision: https://reviews.llvm.org/D70459
Diffstat (limited to 'llvm/lib/Analysis')
| -rw-r--r-- | llvm/lib/Analysis/ScalarEvolution.cpp | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp index 4cde0171f62..79b35b8c9d2 100644 --- a/llvm/lib/Analysis/ScalarEvolution.cpp +++ b/llvm/lib/Analysis/ScalarEvolution.cpp @@ -7246,6 +7246,11 @@ ScalarEvolution::ExitLimit ScalarEvolution::computeExitLimitFromCondImpl( ExitLimit EL1 = computeExitLimitFromCondCached( Cache, L, BO->getOperand(1), ExitIfTrue, ControlsExit && !EitherMayExit, AllowPredicates); + // Be robust against unsimplified IR for the form "and i1 X, true" + if (ConstantInt *CI = dyn_cast<ConstantInt>(BO->getOperand(1))) + return CI->isOne() ? EL0 : EL1; + if (ConstantInt *CI = dyn_cast<ConstantInt>(BO->getOperand(0))) + return CI->isOne() ? EL1 : EL0; const SCEV *BECount = getCouldNotCompute(); const SCEV *MaxBECount = getCouldNotCompute(); if (EitherMayExit) { @@ -7294,6 +7299,11 @@ ScalarEvolution::ExitLimit ScalarEvolution::computeExitLimitFromCondImpl( ExitLimit EL1 = computeExitLimitFromCondCached( Cache, L, BO->getOperand(1), ExitIfTrue, ControlsExit && !EitherMayExit, AllowPredicates); + // Be robust against unsimplified IR for the form "or i1 X, true" + if (ConstantInt *CI = dyn_cast<ConstantInt>(BO->getOperand(1))) + return CI->isZero() ? EL0 : EL1; + if (ConstantInt *CI = dyn_cast<ConstantInt>(BO->getOperand(0))) + return CI->isZero() ? EL1 : EL0; const SCEV *BECount = getCouldNotCompute(); const SCEV *MaxBECount = getCouldNotCompute(); if (EitherMayExit) { |
