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authorChris Lattner <sabre@nondot.org>2008-07-13 21:55:46 +0000
committerChris Lattner <sabre@nondot.org>2008-07-13 21:55:46 +0000
commit5eed37224ae84ece9618f81e049792dd86c4ab9b (patch)
treecab4330ddf7f9adcdc2bbc7e2bafc7ec9ffaf5a6 /llvm/lib
parent9aada1d7557a058ec1f52f65b5720ede5d053b1a (diff)
downloadbcm5719-llvm-5eed37224ae84ece9618f81e049792dd86c4ab9b.tar.gz
bcm5719-llvm-5eed37224ae84ece9618f81e049792dd86c4ab9b.zip
improve comments.
llvm-svn: 53531
Diffstat (limited to 'llvm/lib')
-rw-r--r--llvm/lib/Transforms/Utils/SimplifyCFG.cpp6
1 files changed, 4 insertions, 2 deletions
diff --git a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
index 74e83a66a27..ba9332bd066 100644
--- a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
+++ b/llvm/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) {
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