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| author | Noah Goldstein <goldstein.w.n@gmail.com> | 2024-04-08 23:33:06 -0500 |
|---|---|---|
| committer | Noah Goldstein <goldstein.w.n@gmail.com> | 2024-04-08 23:33:06 -0500 |
| commit | b65ab0b726ce421cc6cd7fdfbf51bf4aba17ce87 (patch) | |
| tree | 6e9db4162686362bfeec85676c07cdac99037701 /llvm/lib/Analysis/ValueTracking.cpp | |
| parent | 5c056b32350e834924356b1af78504d261d24e42 (diff) | |
| download | llvm-b65ab0b726ce421cc6cd7fdfbf51bf4aba17ce87.zip llvm-b65ab0b726ce421cc6cd7fdfbf51bf4aba17ce87.tar.gz llvm-b65ab0b726ce421cc6cd7fdfbf51bf4aba17ce87.tar.bz2 | |
[ValueTracking] Add comment clarifying missing `usub.sat` in `isKnownNonZero`; NFC
Closes #87700
Diffstat (limited to 'llvm/lib/Analysis/ValueTracking.cpp')
| -rw-r--r-- | llvm/lib/Analysis/ValueTracking.cpp | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp index d50ccd8..6602db4 100644 --- a/llvm/lib/Analysis/ValueTracking.cpp +++ b/llvm/lib/Analysis/ValueTracking.cpp @@ -2816,6 +2816,8 @@ static bool isKnownNonZeroFromOperator(const Operator *I, case Intrinsic::bswap: case Intrinsic::ctpop: return isKnownNonZero(II->getArgOperand(0), DemandedElts, Depth, Q); + // NB: We don't do usub_sat here as in any case we can prove its + // non-zero, we will fold it to `sub nuw` in InstCombine. case Intrinsic::ssub_sat: return isNonZeroSub(DemandedElts, Depth, Q, BitWidth, II->getArgOperand(0), II->getArgOperand(1)); |