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When splitting exit edges to canonicalize loops, make sure to put the new

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block in the appropriate loop nest.

Third time is the charm, right?


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26187 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2006-02-14 22:34:08 +00:00
parent ae302ab9cb
commit c27e056d4f
1 changed files with 20 additions and 18 deletions
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38
lib/Transforms/Utils/LoopSimplify.cpp
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@ -57,6 +57,7 @@ namespace {
// AA - If we have an alias analysis object to update, this is it, otherwise
// this is null.
AliasAnalysis *AA;
LoopInfo *LI;
virtual bool runOnFunction(Function &F);
@ -100,10 +101,10 @@ FunctionPass *llvm::createLoopSimplifyPass() { return new LoopSimplify(); }
///
bool LoopSimplify::runOnFunction(Function &F) {
bool Changed = false;
LoopInfo &LI = getAnalysis<LoopInfo>();
LI = &getAnalysis<LoopInfo>();
AA = getAnalysisToUpdate<AliasAnalysis>();
for (LoopInfo::iterator I = LI.begin(), E = LI.end(); I != E; ++I)
for (LoopInfo::iterator I = LI->begin(), E = LI->end(); I != E; ++I)
Changed |= ProcessLoop(*I);
return Changed;
@ -159,9 +160,8 @@ bool LoopSimplify::ProcessLoop(Loop *L) {
// predecessors from outside of the loop, split the edge now.
std::vector<BasicBlock*> ExitBlocks;
L->getExitBlocks(ExitBlocks);
SetVector<BasicBlock*> ExitBlockSet(ExitBlocks.begin(), ExitBlocks.end());
LoopInfo &LI = getAnalysis<LoopInfo>();
for (SetVector<BasicBlock*>::iterator I = ExitBlockSet.begin(),
E = ExitBlockSet.end(); I != E; ++I) {
BasicBlock *ExitBlock = *I;
@ -326,7 +326,7 @@ void LoopSimplify::InsertPreheaderForLoop(Loop *L) {
// We know that we have loop information to update... update it now.
if (Loop *Parent = L->getParentLoop())
Parent->addBasicBlockToLoop(NewBB, getAnalysis<LoopInfo>());
Parent->addBasicBlockToLoop(NewBB, *LI);
DominatorSet &DS = getAnalysis<DominatorSet>(); // Update dominator info
DominatorTree &DT = getAnalysis<DominatorTree>();
@ -414,8 +414,6 @@ void LoopSimplify::InsertPreheaderForLoop(Loop *L) {
/// blocks. This method is used to split exit blocks that have predecessors
/// outside of the loop.
BasicBlock *LoopSimplify::RewriteLoopExitBlock(Loop *L, BasicBlock *Exit) {
DominatorSet &DS = getAnalysis<DominatorSet>();
std::vector<BasicBlock*> LoopBlocks;
for (pred_iterator I = pred_begin(Exit), E = pred_end(Exit); I != E; ++I)
if (L->contains(*I))
@ -424,10 +422,16 @@ BasicBlock *LoopSimplify::RewriteLoopExitBlock(Loop *L, BasicBlock *Exit) {
assert(!LoopBlocks.empty() && "No edges coming in from outside the loop?");
BasicBlock *NewBB = SplitBlockPredecessors(Exit, ".loopexit", LoopBlocks);
// Update Loop Information - we know that the new block will be in the parent
// loop of L.
if (Loop *Parent = L->getParentLoop())
Parent->addBasicBlockToLoop(NewBB, getAnalysis<LoopInfo>());
// Update Loop Information - we know that the new block will be in whichever
// loop the Exit block is in. Note that it may not be in that immediate loop,
// if the successor is some other loop header. In that case, we continue
// walking up the loop tree to find a loop that contains both the successor
// block and the predecessor block.
Loop *SuccLoop = LI->getLoopFor(Exit);
while (SuccLoop && !SuccLoop->contains(L->getHeader()))
SuccLoop = SuccLoop->getParentLoop();
if (SuccLoop)
SuccLoop->addBasicBlockToLoop(NewBB, *LI);
// Update dominator information (set, immdom, domtree, and domfrontier)
UpdateDomInfoForRevectoredPreds(NewBB, LoopBlocks);
@ -511,17 +515,15 @@ Loop *LoopSimplify::SeparateNestedLoop(Loop *L) {
// Create the new outer loop.
Loop *NewOuter = new Loop();
LoopInfo &LI = getAnalysis<LoopInfo>();
// Change the parent loop to use the outer loop as its child now.
if (Loop *Parent = L->getParentLoop())
Parent->replaceChildLoopWith(L, NewOuter);
else
LI.changeTopLevelLoop(L, NewOuter);
LI->changeTopLevelLoop(L, NewOuter);
// This block is going to be our new header block: add it to this loop and all
// parent loops.
NewOuter->addBasicBlockToLoop(NewBB, getAnalysis<LoopInfo>());
NewOuter->addBasicBlockToLoop(NewBB, *LI);
// L is now a subloop of our outer loop.
NewOuter->addChildLoop(L);
@ -553,8 +555,8 @@ Loop *LoopSimplify::SeparateNestedLoop(Loop *L) {
if (!BlocksInL.count(BB)) {
// Move this block to the parent, updating the exit blocks sets
L->removeBlockFromLoop(BB);
if (LI[BB] == L)
LI.changeLoopFor(BB, NewOuter);
if ((*LI)[BB] == L)
LI->changeLoopFor(BB, NewOuter);
--i;
}
}
@ -656,7 +658,7 @@ void LoopSimplify::InsertUniqueBackedgeBlock(Loop *L) {
// Update Loop Information - we know that this block is now in the current
// loop and all parent loops.
L->addBasicBlockToLoop(BEBlock, getAnalysis<LoopInfo>());
L->addBasicBlockToLoop(BEBlock, *LI);
// Update dominator information (set, immdom, domtree, and domfrontier)
UpdateDomInfoForRevectoredPreds(BEBlock, BackedgeBlocks);