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Handle PHINode with only one incoming value. 

This fixes http://llvm.org/bugs/show_bug.cgi?id=979

llvm-svn: 31358
This commit is contained in:
Devang Patel 2006-11-01 22:26:43 +00:00
parent 9db6b328cd
commit 44519a8feb
1 changed files with 9 additions and 5 deletions
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14
llvm/lib/Transforms/Scalar/CondPropagate.cpp
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@ -196,11 +196,15 @@ void CondProp::RevectorBlockTo(BasicBlock *FromBB, BasicBlock *ToBB) {
// Get the old block we are threading through. // Get the old block we are threading through.
BasicBlock *OldSucc = FromBr->getSuccessor(0); BasicBlock *OldSucc = FromBr->getSuccessor(0);
// ToBB should not have any PHI nodes in it to update, because OldSucc had // OldSucc had multiple successors. If ToBB has multiple predecessors, the
// multiple successors. If OldSucc had multiple successor and ToBB had // edge between them would be critical, which we already took care of.
// multiple predecessors, the edge between them would be critical, which we // If ToBB has single operand PHI node than take care of it here.
// already took care of. if (isa<PHINode>(ToBB->begin())) {
assert(!isa<PHINode>(ToBB->begin()) && "Critical Edge Found!"); PHINode *PN = cast<PHINode>(ToBB->begin());
assert(PN->getNumIncomingValues() == 1 && "Critical Edge Found!");
PN->replaceAllUsesWith(PN->getIncomingValue(0));
PN->eraseFromParent();
}
// Update PHI nodes in OldSucc to know that FromBB no longer branches to it. // Update PHI nodes in OldSucc to know that FromBB no longer branches to it.
OldSucc->removePredecessor(FromBB); OldSucc->removePredecessor(FromBB);