diff options
Diffstat (limited to 'llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp')
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp index c59b867..df7f028 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp @@ -2281,8 +2281,10 @@ Instruction *InstCombinerImpl::visitSub(BinaryOperator &I) { if (match(Op0, m_APInt(Op0C))) { if (Op0C->isMask()) { // Turn this into a xor if LHS is 2^n-1 and the remaining bits are known - // zero. - KnownBits RHSKnown = computeKnownBits(Op1, 0, &I); + // zero. We don't use information from dominating conditions so this + // transform is easier to reverse if necessary. + KnownBits RHSKnown = llvm::computeKnownBits( + Op1, 0, SQ.getWithInstruction(&I).getWithoutDomCondCache()); if ((*Op0C | RHSKnown.Zero).isAllOnes()) return BinaryOperator::CreateXor(Op1, Op0); } |