diff options
Diffstat (limited to 'llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp')
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp | 37 |
1 files changed, 20 insertions, 17 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp index 990305b1d8d..1e6e0727955 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp @@ -2212,27 +2212,30 @@ Instruction *InstCombiner::visitICmpInstWithInstAndIntCst(ICmpInst &ICI, } break; case Instruction::Xor: - // For the xor case, we can xor two constants together, eliminating - // the explicit xor. - if (Constant *BOC = dyn_cast<Constant>(BO->getOperand(1))) { - return new ICmpInst(ICI.getPredicate(), BO->getOperand(0), - ConstantExpr::getXor(RHS, BOC)); - } else if (RHSV == 0) { - // Replace ((xor A, B) != 0) with (A != B) - return new ICmpInst(ICI.getPredicate(), BO->getOperand(0), - BO->getOperand(1)); + if (BO->hasOneUse()) { + if (Constant *BOC = dyn_cast<Constant>(BO->getOperand(1))) { + // For the xor case, we can xor two constants together, eliminating + // the explicit xor. + return new ICmpInst(ICI.getPredicate(), BO->getOperand(0), + ConstantExpr::getXor(RHS, BOC)); + } else if (RHSV == 0) { + // Replace ((xor A, B) != 0) with (A != B) + return new ICmpInst(ICI.getPredicate(), BO->getOperand(0), + BO->getOperand(1)); + } } break; case Instruction::Sub: - // Replace ((sub A, B) != C) with (B != A-C) if A & C are constants. - if (ConstantInt *BOp0C = dyn_cast<ConstantInt>(BO->getOperand(0))) { - if (BO->hasOneUse()) + if (BO->hasOneUse()) { + if (ConstantInt *BOp0C = dyn_cast<ConstantInt>(BO->getOperand(0))) { + // Replace ((sub A, B) != C) with (B != A-C) if A & C are constants. return new ICmpInst(ICI.getPredicate(), BO->getOperand(1), - ConstantExpr::getSub(BOp0C, RHS)); - } else if (RHSV == 0) { - // Replace ((sub A, B) != 0) with (A != B) - return new ICmpInst(ICI.getPredicate(), BO->getOperand(0), - BO->getOperand(1)); + ConstantExpr::getSub(BOp0C, RHS)); + } else if (RHSV == 0) { + // Replace ((sub A, B) != 0) with (A != B) + return new ICmpInst(ICI.getPredicate(), BO->getOperand(0), + BO->getOperand(1)); + } } break; case Instruction::Or: |
