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| author | Noah Goldstein <goldstein.w.n@gmail.com> | 2023-04-14 14:34:23 -0500 |
|---|---|---|
| committer | Noah Goldstein <goldstein.w.n@gmail.com> | 2023-04-14 18:23:47 -0500 |
| commit | f688d215e53cdeaaa90b317bb476acd6cebabf2c (patch) | |
| tree | fbfbeaf698c909f124f3732bc0bcc0a6fc727b14 /llvm/lib/Analysis/ValueTracking.cpp | |
| parent | 684963b86db3d4d1eebd3985b8161af90187e938 (diff) | |
| download | llvm-f688d215e53cdeaaa90b317bb476acd6cebabf2c.zip llvm-f688d215e53cdeaaa90b317bb476acd6cebabf2c.tar.gz llvm-f688d215e53cdeaaa90b317bb476acd6cebabf2c.tar.bz2 | |
[ValueTracking] Add `shl nsw %val, %cnt != 0` if `%val != 0`.
Alive2 Link: https://alive2.llvm.org/ce/z/mxZLJn
Reviewed By: nikic
Differential Revision: https://reviews.llvm.org/D147898
Diffstat (limited to 'llvm/lib/Analysis/ValueTracking.cpp')
| -rw-r--r-- | llvm/lib/Analysis/ValueTracking.cpp | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp index 3a9e80c..eae6261 100644 --- a/llvm/lib/Analysis/ValueTracking.cpp +++ b/llvm/lib/Analysis/ValueTracking.cpp @@ -2670,9 +2670,9 @@ bool isKnownNonZero(const Value *V, const APInt &DemandedElts, unsigned Depth, return isKnownNonZero(I->getOperand(0), Depth, Q); case Instruction::Shl: { - // shl nuw can't remove any non-zero bits. + // shl nsw/nuw can't remove any non-zero bits. const OverflowingBinaryOperator *BO = cast<OverflowingBinaryOperator>(V); - if (Q.IIQ.hasNoUnsignedWrap(BO)) + if (Q.IIQ.hasNoUnsignedWrap(BO) || Q.IIQ.hasNoSignedWrap(BO)) return isKnownNonZero(I->getOperand(0), Depth, Q); // shl X, Y != 0 if X is odd. Note that the value of the shift is undefined |