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Improve some _slow_ behavior introduced in my patches the last few days.

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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35839 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Owen Anderson 2007-04-09 22:25:09 +00:00
parent 43979df430
commit 17cba6d232
1 changed files with 42 additions and 42 deletions
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84
lib/Transforms/Utils/LoopSimplify.cpp
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@ -673,6 +673,16 @@ void LoopSimplify::InsertUniqueBackedgeBlock(Loop *L) {
UpdateDomInfoForRevectoredPreds(BEBlock, BackedgeBlocks);
}
// Returns true if BasicBlock A dominates at least one block in vector B
// Helper function for UpdateDomInfoForRevectoredPreds
static bool BlockDominatesAny(BasicBlock* A, std::vector<BasicBlock*>& B, ETForest& ETF) {
for (std::vector<BasicBlock*>::iterator BI = B.begin(), BE = B.end(); BI != BE; ++BI) {
if (ETF.dominates(A, *BI))
return true;
}
return false;
}
/// UpdateDomInfoForRevectoredPreds - This method is used to update the four
/// different kinds of dominator information (immediate dominators,
/// dominator trees, et-forest and dominance frontiers) after a new block has
@ -841,47 +851,37 @@ void LoopSimplify::UpdateDomInfoForRevectoredPreds(BasicBlock *NewBB,
// blocks that dominate a block in PredBlocks and contained NewBBSucc in
// their dominance frontier must be updated to contain NewBB instead.
//
for (unsigned i = 0, e = PredBlocks.size(); i != e; ++i) {
BasicBlock *Pred = PredBlocks[i];
// Get all of the dominators of the predecessor...
// FIXME: There's probably a better way to do this...
std::vector<BasicBlock*> PredDoms;
for (Function::iterator I = Pred->getParent()->begin(),
E = Pred->getParent()->end(); I != E; ++I)
if (ETF.dominates(&(*I), Pred))
PredDoms.push_back(I);
for (std::vector<BasicBlock*>::const_iterator PDI = PredDoms.begin(),
PDE = PredDoms.end(); PDI != PDE; ++PDI) {
BasicBlock *PredDom = *PDI;
// If the NewBBSucc node is in DF(PredDom), then PredDom didn't
// dominate NewBBSucc but did dominate a predecessor of it. Now we
// change this entry to include NewBB in the DF instead of NewBBSucc.
DominanceFrontier::iterator DFI = DF->find(PredDom);
assert(DFI != DF->end() && "No dominance frontier for node?");
if (DFI->second.count(NewBBSucc)) {
// If NewBBSucc should not stay in our dominator frontier, remove it.
// We remove it unless there is a predecessor of NewBBSucc that we
// dominate, but we don't strictly dominate NewBBSucc.
bool ShouldRemove = true;
if (PredDom == NewBBSucc || !ETF.dominates(PredDom, NewBBSucc)) {
// Okay, we know that PredDom does not strictly dominate NewBBSucc.
// Check to see if it dominates any predecessors of NewBBSucc.
for (pred_iterator PI = pred_begin(NewBBSucc),
E = pred_end(NewBBSucc); PI != E; ++PI)
if (ETF.dominates(PredDom, *PI)) {
ShouldRemove = false;
break;
}
}
if (ShouldRemove)
DF->removeFromFrontier(DFI, NewBBSucc);
DF->addToFrontier(DFI, NewBB);
}
}
}
}
for (Function::iterator FI = NewBB->getParent()->begin(),
FE = NewBB->getParent()->end(); FI != FE; ++FI) {
DominanceFrontier::iterator DFI = DF->find(FI);
if (DFI == DF->end()) continue; // unreachable block.
// Only consider dominators of NewBBSucc
if (!DFI->second.count(NewBBSucc)) continue;
if (BlockDominatesAny(FI, PredBlocks, ETF)) {
// If NewBBSucc should not stay in our dominator frontier, remove it.
// We remove it unless there is a predecessor of NewBBSucc that we
// dominate, but we don't strictly dominate NewBBSucc.
bool ShouldRemove = true;
if ((BasicBlock*)FI == NewBBSucc || !ETF.dominates(FI, NewBBSucc)) {
// Okay, we know that PredDom does not strictly dominate NewBBSucc.
// Check to see if it dominates any predecessors of NewBBSucc.
for (pred_iterator PI = pred_begin(NewBBSucc),
E = pred_end(NewBBSucc); PI != E; ++PI)
if (ETF.dominates(FI, *PI)) {
ShouldRemove = false;
break;
}
if (ShouldRemove)
DF->removeFromFrontier(DFI, NewBBSucc);
DF->addToFrontier(DFI, NewBB);
break;
}
}
}
}
}