diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Transforms/Scalar/InstructionCombining.cpp | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp index 67c40fe21c..3b181c85d2 100644 --- a/lib/Transforms/Scalar/InstructionCombining.cpp +++ b/lib/Transforms/Scalar/InstructionCombining.cpp @@ -5043,8 +5043,12 @@ Instruction *InstCombiner::visitFCmpInst(FCmpInst &I) { if (Instruction *LHSI = dyn_cast<Instruction>(Op0)) switch (LHSI->getOpcode()) { case Instruction::PHI: - if (Instruction *NV = FoldOpIntoPhi(I)) - return NV; + // Only fold fcmp into the PHI if the phi and fcmp are in the same + // block. If in the same block, we're encouraging jump threading. If + // not, we are just pessimizing the code by making an i1 phi. + if (LHSI->getParent() == I.getParent()) + if (Instruction *NV = FoldOpIntoPhi(I)) + return NV; break; case Instruction::SIToFP: case Instruction::UIToFP: @@ -5348,8 +5352,12 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { break; case Instruction::PHI: - if (Instruction *NV = FoldOpIntoPhi(I)) - return NV; + // Only fold icmp into the PHI if the phi and fcmp are in the same + // block. If in the same block, we're encouraging jump threading. If + // not, we are just pessimizing the code by making an i1 phi. + if (LHSI->getParent() == I.getParent()) + if (Instruction *NV = FoldOpIntoPhi(I)) + return NV; break; case Instruction::Select: { // If either operand of the select is a constant, we can fold the |