Revert r70645 for now; it's causing a variety of regressions.

llvm-svn: 70661

1 files changed, 20 insertions, 3 deletions

diff --git a/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp b/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
index 7d69dc83339..b9406651525 100644
--- a/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
@@ -253,6 +253,8 @@ void LoopStrengthReduce::DeleteTriviallyDeadInstructions() {
     if (I == 0 || !isInstructionTriviallyDead(I))
       continue;
 
+    SE->deleteValueFromRecords(I);
+
     for (User::op_iterator OI = I->op_begin(), E = I->op_end(); OI != E; ++OI) {
       if (Instruction *U = dyn_cast<Instruction>(*OI)) {
         *OI = 0;
@@ -2128,6 +2130,7 @@ ICmpInst *LoopStrengthReduce::ChangeCompareStride(Loop *L, ICmpInst *Cond,
 
     // Remove the old compare instruction. The old indvar is probably dead too.
     DeadInsts.push_back(cast<Instruction>(CondUse->OperandValToReplace));
+    SE->deleteValueFromRecords(OldCond);
     OldCond->replaceAllUsesWith(Cond);
     OldCond->eraseFromParent();
 
@@ -2248,12 +2251,16 @@ ICmpInst *LoopStrengthReduce::OptimizeSMax(Loop *L, ICmpInst *Cond,
                  Cond->getOperand(0), NewRHS, "scmp", Cond);
 
   // Delete the max calculation instructions.
+  SE->deleteValueFromRecords(Cond);
   Cond->replaceAllUsesWith(NewCond);
   Cond->eraseFromParent();
   Instruction *Cmp = cast<Instruction>(Sel->getOperand(0));
+  SE->deleteValueFromRecords(Sel);
   Sel->eraseFromParent();
-  if (Cmp->use_empty())
+  if (Cmp->use_empty()) {
+    SE->deleteValueFromRecords(Cmp);
     Cmp->eraseFromParent();
+  }
   CondUse->User = NewCond;
   return NewCond;
 }
@@ -2360,6 +2367,7 @@ void LoopStrengthReduce::OptimizeShadowIV(Loop *L) {
       NewPH->addIncoming(NewIncr, PH->getIncomingBlock(Latch));
 
       /* Remove cast operation */
+      SE->deleteValueFromRecords(ShadowUse);
       ShadowUse->replaceAllUsesWith(NewPH);
       ShadowUse->eraseFromParent();
       SI->second.Users.erase(CandidateUI);
@@ -2499,8 +2507,17 @@ bool LoopStrengthReduce::runOnLoop(Loop *L, LPPassManager &LPM) {
     DeleteTriviallyDeadInstructions();
 
   // At this point, it is worth checking to see if any recurrence PHIs are also
-  // dead, so that we can remove them as well.
-  DeleteDeadPHIs(L->getHeader());
+  // dead, so that we can remove them as well. To keep ScalarEvolution
+  // current, use a ValueDeletionListener class.
+  struct LSRListener : public ValueDeletionListener {
+    ScalarEvolution &SE;
+    explicit LSRListener(ScalarEvolution &se) : SE(se) {}
+
+    virtual void ValueWillBeDeleted(Value *V) {
+      SE.deleteValueFromRecords(V);
+    }
+  } VDL(*SE);
+  DeleteDeadPHIs(L->getHeader(), &VDL);
 
   return Changed;
 }