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Preserve DominanceFrontier. 

llvm-svn: 37820
This commit is contained in:
Devang Patel 2007-06-29 23:11:49 +00:00
parent 2e5e277cb3
commit 0975c6d7f9
1 changed files with 29 additions and 5 deletions
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34
llvm/lib/Transforms/Scalar/LoopUnswitch.cpp
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@ -84,6 +84,7 @@ namespace {
AU.addRequiredID(LoopSimplifyID);
AU.addPreservedID(LoopSimplifyID);
AU.addPreserved<DominatorTree>();
AU.addPreserved<DominanceFrontier>();
AU.addRequired<LoopInfo>();
AU.addPreserved<LoopInfo>();
AU.addRequiredID(LCSSAID);
@ -415,6 +416,9 @@ BasicBlock *LoopUnswitch::SplitBlock(BasicBlock *Old, Instruction *SplitPt) {
if (DominatorTree *DT = getAnalysisToUpdate<DominatorTree>())
DT->addNewBlock(New, Old);
if (DominanceFrontier *DF = getAnalysisToUpdate<DominanceFrontier>())
DF->splitBlock(Old);
return New;
}
@ -471,7 +475,7 @@ static inline void RemapInstruction(Instruction *I,
// If Orig is in Loop then find and use Orig dominator's cloned block as NewBB
// dominator.
void CloneDomInfo(BasicBlock *NewBB, BasicBlock *Orig, Loop *L,
DominatorTree *DT,
DominatorTree *DT, DominanceFrontier *DF,
DenseMap<const Value*, Value*> &VM) {
DomTreeNode *OrigNode = DT->getNode(Orig);
@ -481,7 +485,7 @@ void CloneDomInfo(BasicBlock *NewBB, BasicBlock *Orig, Loop *L,
BasicBlock *NewIDom = OrigIDom;
if (L->contains(OrigIDom)) {
if (!DT->getNode(OrigIDom))
CloneDomInfo(NewIDom, OrigIDom, L, DT, VM);
CloneDomInfo(NewIDom, OrigIDom, L, DT, DF, VM);
NewIDom = cast<BasicBlock>(VM[OrigIDom]);
}
if (NewBB == NewIDom) {
@ -489,6 +493,23 @@ void CloneDomInfo(BasicBlock *NewBB, BasicBlock *Orig, Loop *L,
DT->changeImmediateDominator(NewBB, NewIDom);
} else
DT->addNewBlock(NewBB, NewIDom);
DominanceFrontier::DomSetType NewDFSet;
if (DF) {
DominanceFrontier::iterator DFI = DF->find(Orig);
if ( DFI != DF->end()) {
DominanceFrontier::DomSetType S = DFI->second;
for (DominanceFrontier::DomSetType::iterator I = S.begin(), E = S.end();
I != E; ++I) {
BasicBlock *BB = *I;
if (L->contains(BB))
NewDFSet.insert(cast<BasicBlock>(VM[Orig]));
else
NewDFSet.insert(BB);
}
}
DF->addBasicBlock(NewBB, NewDFSet);
}
}
/// CloneLoop - Recursively clone the specified loop and all of its children,
@ -532,12 +553,14 @@ void LoopUnswitch::EmitPreheaderBranchOnCondition(Value *LIC, Constant *Val,
BranchInst *BRI = new BranchInst(TrueDest, FalseDest, BranchVal, InsertPt);
// Update dominator info.
// BranchVal is a new preheader so it dominates true and false destination
// loop headers.
if (DominatorTree *DT = getAnalysisToUpdate<DominatorTree>()) {
// BranchVal is a new preheader so it dominates true and false destination
// loop headers.
DT->changeImmediateDominator(TrueDest, BRI->getParent());
DT->changeImmediateDominator(FalseDest, BRI->getParent());
}
// No need to update DominanceFrontier. BRI->getParent() dominated TrueDest
// and FalseDest anyway. Now it immediately dominates them.
}
@ -679,11 +702,12 @@ void LoopUnswitch::UnswitchNontrivialCondition(Value *LIC, Constant *Val,
}
// Update dominator info
DominanceFrontier *DF = getAnalysisToUpdate<DominanceFrontier>();
if (DominatorTree *DT = getAnalysisToUpdate<DominatorTree>())
for (unsigned i = 0, e = LoopBlocks.size(); i != e; ++i) {
BasicBlock *LBB = LoopBlocks[i];
BasicBlock *NBB = NewBlocks[i];
CloneDomInfo(NBB, LBB, L, DT, ValueMap);
CloneDomInfo(NBB, LBB, L, DT, DF, ValueMap);
}
// Splice the newly inserted blocks into the function right before the