Reapply the new LoopStrengthReduction code, with compile time and
bug fixes, and with improved heuristics for analyzing foreign-loop
addrecs.
This change also flattens IVUsers, eliminating the stride-oriented
groupings, which makes it easier to work with.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95975 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/ScalarEvolutionExpander.cpp b/lib/Analysis/ScalarEvolutionExpander.cpp
index 4310e3c..9439d08 100644
--- a/lib/Analysis/ScalarEvolutionExpander.cpp
+++ b/lib/Analysis/ScalarEvolutionExpander.cpp
@@ -641,8 +641,24 @@
// Reuse a previously-inserted PHI, if present.
for (BasicBlock::iterator I = L->getHeader()->begin();
PHINode *PN = dyn_cast<PHINode>(I); ++I)
- if (isInsertedInstruction(PN) && SE.getSCEV(PN) == Normalized)
- return PN;
+ if (SE.isSCEVable(PN->getType()) &&
+ (SE.getEffectiveSCEVType(PN->getType()) ==
+ SE.getEffectiveSCEVType(Normalized->getType())) &&
+ SE.getSCEV(PN) == Normalized)
+ if (BasicBlock *LatchBlock = L->getLoopLatch()) {
+ // Remember this PHI, even in post-inc mode.
+ InsertedValues.insert(PN);
+ // Remember the increment.
+ Instruction *IncV =
+ cast<Instruction>(PN->getIncomingValueForBlock(LatchBlock)
+ ->stripPointerCasts());
+ rememberInstruction(IncV);
+ // Make sure the increment is where we want it. But don't move it
+ // down past a potential existing post-inc user.
+ if (L == IVIncInsertLoop && !SE.DT->dominates(IncV, IVIncInsertPos))
+ IncV->moveBefore(IVIncInsertPos);
+ return PN;
+ }
// Save the original insertion point so we can restore it when we're done.
BasicBlock *SaveInsertBB = Builder.GetInsertBlock();