diff options
| -rw-r--r-- | lib/Transforms/Scalar/InstructionCombining.cpp | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp index 8bc909196a..f8ad98c517 100644 --- a/lib/Transforms/Scalar/InstructionCombining.cpp +++ b/lib/Transforms/Scalar/InstructionCombining.cpp @@ -9354,6 +9354,14 @@ Instruction *InstCombiner::FoldPHIArgOpIntoPHI(PHINode &PN) { if (LI->getParent() != PN.getIncomingBlock(0) || !isSafeToSinkLoad(LI)) return 0; + + // If the PHI is of volatile loads and the load block has multiple + // successors, sinking it would remove a load of the volatile value from + // the path through the other successor. + if (isVolatile && + LI->getParent()->getTerminator()->getNumSuccessors() != 1) + return 0; + } else if (isa<GetElementPtrInst>(FirstInst)) { if (FirstInst->getNumOperands() == 2) return FoldPHIArgBinOpIntoPHI(PN); @@ -9380,9 +9388,9 @@ Instruction *InstCombiner::FoldPHIArgOpIntoPHI(PHINode &PN) { !isSafeToSinkLoad(LI)) return 0; - // If the PHI is volatile and its block has multiple successors, sinking - // it would remove a load of the volatile value from the path through the - // other successor. + // If the PHI is of volatile loads and the load block has multiple + // successors, sinking it would remove a load of the volatile value from + // the path through the other successor. if (isVolatile && LI->getParent()->getTerminator()->getNumSuccessors() != 1) return 0; |