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Fix PR1110 and Analysis/Dominators/2007-01-14-BreakCritEdges.ll by being

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more careful about unreachable code when updating dominator info.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@33204 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2007-01-14 18:33:35 +00:00
parent 5a42a935b2
commit 9fa58b5f66
1 changed files with 40 additions and 35 deletions
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75
lib/Transforms/Utils/BreakCriticalEdges.cpp
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@ -182,49 +182,54 @@ bool llvm::SplitCriticalEdge(TerminatorInst *TI, unsigned SuccNum, Pass *P,
// Should we update DominatorSet information?
if (DominatorSet *DS = P->getAnalysisToUpdate<DominatorSet>()) {
// The blocks that dominate the new one are the blocks that dominate TIBB
// plus the new block itself.
DominatorSet::DomSetType DomSet = DS->getDominators(TIBB);
DomSet.insert(NewBB); // A block always dominates itself.
DS->addBasicBlock(NewBB, DomSet);
// If NewBBDominatesDestBB hasn't been computed yet, do so with DS.
if (!OtherPreds.empty()) {
while (!OtherPreds.empty() && NewBBDominatesDestBB) {
NewBBDominatesDestBB = DS->dominates(DestBB, OtherPreds.back());
OtherPreds.pop_back();
DominatorSet::iterator DSI = DS->find(TIBB);
if (DSI != DS->end()) { // TIBB is reachable?
// The blocks that dominate the new one are the blocks that dominate TIBB
// plus the new block itself.
DominatorSet::DomSetType DomSet = DSI->second; // Copy domset.
DomSet.insert(NewBB); // A block always dominates itself.
DS->addBasicBlock(NewBB, DomSet);
// If NewBBDominatesDestBB hasn't been computed yet, do so with DS.
if (!OtherPreds.empty()) {
while (!OtherPreds.empty() && NewBBDominatesDestBB) {
NewBBDominatesDestBB = DS->dominates(DestBB, OtherPreds.back());
OtherPreds.pop_back();
}
OtherPreds.clear();
}
// If NewBBDominatesDestBB, then NewBB dominates DestBB, otherwise it
// doesn't dominate anything. If NewBB does dominates DestBB, then it
// dominates everything that DestBB dominates.
if (NewBBDominatesDestBB) {
for (DominatorSet::iterator I = DS->begin(), E = DS->end(); I != E; ++I)
if (I->second.count(DestBB))
I->second.insert(NewBB);
}
OtherPreds.clear();
}
// If NewBBDominatesDestBB, then NewBB dominates DestBB, otherwise it
// doesn't dominate anything. If NewBB does dominates DestBB, then it
// dominates everything that DestBB dominates.
if (NewBBDominatesDestBB) {
for (DominatorSet::iterator I = DS->begin(), E = DS->end(); I != E; ++I)
if (I->second.count(DestBB))
I->second.insert(NewBB);
}
}
// Should we update ImmediateDominator information?
if (ImmediateDominators *ID = P->getAnalysisToUpdate<ImmediateDominators>()) {
// TIBB is the new immediate dominator for NewBB.
ID->addNewBlock(NewBB, TIBB);
// If NewBBDominatesDestBB hasn't been computed yet, do so with ID.
if (!OtherPreds.empty()) {
while (!OtherPreds.empty() && NewBBDominatesDestBB) {
NewBBDominatesDestBB = ID->dominates(DestBB, OtherPreds.back());
OtherPreds.pop_back();
if (ID->get(TIBB)) { // Only do this if TIBB is reachable.
// TIBB is the new immediate dominator for NewBB.
ID->addNewBlock(NewBB, TIBB);
// If NewBBDominatesDestBB hasn't been computed yet, do so with ID.
if (!OtherPreds.empty()) {
while (!OtherPreds.empty() && NewBBDominatesDestBB) {
NewBBDominatesDestBB = ID->dominates(DestBB, OtherPreds.back());
OtherPreds.pop_back();
}
OtherPreds.clear();
}
OtherPreds.clear();
// If NewBBDominatesDestBB, then NewBB dominates DestBB, otherwise it
// doesn't dominate anything.
if (NewBBDominatesDestBB)
ID->setImmediateDominator(DestBB, NewBB);
}
// If NewBBDominatesDestBB, then NewBB dominates DestBB, otherwise it
// doesn't dominate anything.
if (NewBBDominatesDestBB)
ID->setImmediateDominator(DestBB, NewBB);
}
// Update the forest?