Revert r80926. It causes loop unswitch assertion and slow down some JIT tests significantly.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81101 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Utils/LoopSimplify.cpp b/lib/Transforms/Utils/LoopSimplify.cpp
index 36709f7..56e5a46 100644
--- a/lib/Transforms/Utils/LoopSimplify.cpp
+++ b/lib/Transforms/Utils/LoopSimplify.cpp
@@ -69,8 +69,8 @@
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
// We need loop information to identify the loops...
- AU.addRequiredTransitive<LoopInfo>();
- AU.addRequiredTransitive<DominatorTree>();
+ AU.addRequired<LoopInfo>();
+ AU.addRequired<DominatorTree>();
AU.addPreserved<LoopInfo>();
AU.addPreserved<DominatorTree>();
@@ -83,13 +83,9 @@
void verifyAnalysis() const {
#ifndef NDEBUG
LoopInfo *NLI = &getAnalysis<LoopInfo>();
- for (LoopInfo::iterator I = NLI->begin(), E = NLI->end(); I != E; ++I) {
- // Sanity check: Check basic loop invariants.
+ for (LoopInfo::iterator I = NLI->begin(), E = NLI->end(); I != E; ++I)
(*I)->verifyLoop();
- // Check the special guarantees that LoopSimplify makes.
- assert((*I)->isLoopSimplifyForm());
- }
-#endif
+#endif
}
private:
@@ -350,6 +346,15 @@
BasicBlock *NewBB =
SplitBlockPredecessors(Header, &OutsideBlocks[0], OutsideBlocks.size(),
".preheader", this);
+
+
+ //===--------------------------------------------------------------------===//
+ // Update analysis results now that we have performed the transformation
+ //
+
+ // We know that we have loop information to update... update it now.
+ if (Loop *Parent = L->getParentLoop())
+ Parent->addBasicBlockToLoop(NewBB, LI->getBase());
// Make sure that NewBB is put someplace intelligent, which doesn't mess up
// code layout too horribly.
@@ -372,6 +377,17 @@
LoopBlocks.size(), ".loopexit",
this);
+ // 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->getBase());
+
return NewBB;
}
@@ -505,6 +521,10 @@
else
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, LI->getBase());
+
// L is now a subloop of our outer loop.
NewOuter->addChildLoop(L);
@@ -512,10 +532,6 @@
I != E; ++I)
NewOuter->addBlockEntry(*I);
- // Now reset the header in L, which had been moved by
- // SplitBlockPredecessors for the outer loop.
- L->moveToHeader(Header);
-
// Determine which blocks should stay in L and which should be moved out to
// the Outer loop now.
std::set<BasicBlock*> BlocksInL;