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| author | Noah Goldstein <goldstein.w.n@gmail.com> | 2023-08-07 10:35:27 -0500 |
|---|---|---|
| committer | Noah Goldstein <goldstein.w.n@gmail.com> | 2023-08-09 14:42:55 -0500 |
| commit | dff3d8a279c660694b50271523edbc98c3eb2ab6 (patch) | |
| tree | a548de399660ed5bed38ca8dc54d3957c91a864f /llvm/lib/Analysis/ValueTracking.cpp | |
| parent | 4f818daca64ccec5557c10a05186837cf9fcd0f7 (diff) | |
| download | llvm-dff3d8a279c660694b50271523edbc98c3eb2ab6.zip llvm-dff3d8a279c660694b50271523edbc98c3eb2ab6.tar.gz llvm-dff3d8a279c660694b50271523edbc98c3eb2ab6.tar.bz2 | |
[ValueTracking] Add support for `mul` in `isKnownToBeAPowerOfTwo`
pow2 * pow2 is a power of 2 or zero.
Proof: https://alive2.llvm.org/ce/z/FNiiXd
Differential Revision: https://reviews.llvm.org/D157308
Diffstat (limited to 'llvm/lib/Analysis/ValueTracking.cpp')
| -rw-r--r-- | llvm/lib/Analysis/ValueTracking.cpp | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp index f408946..d82c83c 100644 --- a/llvm/lib/Analysis/ValueTracking.cpp +++ b/llvm/lib/Analysis/ValueTracking.cpp @@ -2050,6 +2050,10 @@ bool isKnownToBeAPowerOfTwo(const Value *V, bool OrZero, unsigned Depth, if (Q.IIQ.isExact(cast<BinaryOperator>(I))) return isKnownToBeAPowerOfTwo(I->getOperand(0), OrZero, Depth, Q); return false; + case Instruction::Mul: + return OrZero && + isKnownToBeAPowerOfTwo(I->getOperand(1), OrZero, Depth, Q) && + isKnownToBeAPowerOfTwo(I->getOperand(0), OrZero, Depth, Q); case Instruction::And: if (OrZero) { // A power of two and'd with anything is a power of two or zero. |