diff options
| author | Chris Lattner <sabre@nondot.org> | 2008-07-13 21:55:46 +0000 |
|---|---|---|
| committer | Chris Lattner <sabre@nondot.org> | 2008-07-13 21:55:46 +0000 |
| commit | eb388af89f15ee3de6f53359473e1a54418a667f (patch) | |
| tree | bfa2b91230b6bf57167f826a36d7f68399588750 /lib/Transforms/Utils/SimplifyCFG.cpp | |
| parent | 867661ac8bd8e202bd4becf9b8e046bf69e150b1 (diff) | |
improve comments.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53531 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Transforms/Utils/SimplifyCFG.cpp')
| -rw-r--r-- | lib/Transforms/Utils/SimplifyCFG.cpp | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/lib/Transforms/Utils/SimplifyCFG.cpp b/lib/Transforms/Utils/SimplifyCFG.cpp index 74e83a66a2..ba9332bd06 100644 --- a/lib/Transforms/Utils/SimplifyCFG.cpp +++ b/lib/Transforms/Utils/SimplifyCFG.cpp @@ -1538,6 +1538,9 @@ static bool SimplifyCondBranchToCondBranch(BranchInst *PBI, BranchInst *BI) { PHINode *NewPN = PHINode::Create(Type::Int1Ty, BI->getCondition()->getName() + ".pr", BB->begin()); + // Okay, we're going to insert the PHI node. Since PBI is not the only + // predecessor, compute the PHI'd conditional value for all of the preds. + // Any predecessor where the condition is not computable we keep symbolic. for (pred_iterator PI = pred_begin(BB), E = pred_end(BB); PI != E; ++PI) if ((PBI = dyn_cast<BranchInst>((*PI)->getTerminator())) && PBI != BI && PBI->isConditional() && @@ -1551,7 +1554,6 @@ static bool SimplifyCondBranchToCondBranch(BranchInst *PBI, BranchInst *BI) { } BI->setCondition(NewPN); - // This will thread the branch. return true; } } @@ -1653,7 +1655,7 @@ static bool SimplifyCondBranchToCondBranch(BranchInst *PBI, BranchInst *BI) { // them agree. for (BasicBlock::iterator II = CommonDest->begin(); (PN = dyn_cast<PHINode>(II)); ++II) { - Value * BIV = PN->getIncomingValueForBlock(BB); + Value *BIV = PN->getIncomingValueForBlock(BB); unsigned PBBIdx = PN->getBasicBlockIndex(PBI->getParent()); Value *PBIV = PN->getIncomingValue(PBBIdx); if (BIV != PBIV) { |