diff options
Diffstat (limited to 'llvm/lib')
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp index d0292b640fe..5a14726bee2 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp @@ -333,6 +333,18 @@ Instruction *InstCombiner::foldSelectOpOp(SelectInst &SI, Instruction *TI, TI->getType()); } + // Cond ? -X : -Y --> -(Cond ? X : Y) + Value *X, *Y; + if (match(TI, m_FNeg(m_Value(X))) && match(FI, m_FNeg(m_Value(Y))) && + (TI->hasOneUse() || FI->hasOneUse())) { + Value *NewSel = Builder.CreateSelect(Cond, X, Y, SI.getName() + ".v", &SI); + // TODO: Remove the hack for the binop form when the unary op is optimized + // properly with all IR passes. + if (TI->getOpcode() != Instruction::FNeg) + return BinaryOperator::CreateFNegFMF(NewSel, cast<BinaryOperator>(TI)); + return UnaryOperator::CreateFNeg(NewSel); + } + // Only handle binary operators (including two-operand getelementptr) with // one-use here. As with the cast case above, it may be possible to relax the // one-use constraint, but that needs be examined carefully since it may not |
