diff options
| -rw-r--r-- | lib/Transforms/Scalar/InstructionCombining.cpp | 32 |
1 files changed, 15 insertions, 17 deletions
diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp index 672ed0af1b..e1741a0067 100644 --- a/lib/Transforms/Scalar/InstructionCombining.cpp +++ b/lib/Transforms/Scalar/InstructionCombining.cpp @@ -10981,24 +10981,22 @@ Instruction *InstCombiner::visitPHINode(PHINode &PN) { } } - // If there are multiple PHIs, sort their operands so that they all list - // the blocks in the same order. This will help identical PHIs be eliminated - // by other passes. Other passes shouldn't depend on this for correctness - // however. - PHINode *FirstPN = cast<PHINode>(PN.getParent()->begin()); - if (&PN != FirstPN) - for (unsigned i = 0, e = FirstPN->getNumIncomingValues(); i != e; ++i) { + // Sort the PHI node operands to match the pred iterator order. This will + // help identical PHIs be eliminated by other passes. Other passes shouldn't + // depend on this for correctness however. + unsigned i = 0; + for (pred_iterator PI = pred_begin(PN.getParent()), + PE = pred_end(PN.getParent()); PI != PE; ++PI, ++i) + if (PN.getIncomingBlock(i) != *PI) { + unsigned j = PN.getBasicBlockIndex(*PI); + Value *VA = PN.getIncomingValue(i); BasicBlock *BBA = PN.getIncomingBlock(i); - BasicBlock *BBB = FirstPN->getIncomingBlock(i); - if (BBA != BBB) { - Value *VA = PN.getIncomingValue(i); - unsigned j = FirstPN->getBasicBlockIndex(BBA); - Value *VB = PN.getIncomingValue(j); - PN.setIncomingBlock(i, BBB); - PN.setIncomingValue(i, VB); - PN.setIncomingBlock(j, BBA); - PN.setIncomingValue(j, VA); - } + Value *VB = PN.getIncomingValue(j); + BasicBlock *BBB = PN.getIncomingBlock(j); + PN.setIncomingBlock(i, BBB); + PN.setIncomingValue(i, VB); + PN.setIncomingBlock(j, BBA); + PN.setIncomingValue(j, VA); } return 0; |