Fix a nasty dangling pointer issue. The ScalarEvolution pass would keep a

map from instruction* to SCEVHandles.  When we delete instructions, we have
to tell it about it.  We would run into nasty cases where new instructions
were reallocated at old instruction addresses and get the old map values.
Bad bad bad :(


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22632 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 3 insertions, 1 deletions

diff --git a/lib/Transforms/Scalar/LoopStrengthReduce.cpp b/lib/Transforms/Scalar/LoopStrengthReduce.cpp
index 33714a2ad2..7b1168e0b4 100644
--- a/lib/Transforms/Scalar/LoopStrengthReduce.cpp
+++ b/lib/Transforms/Scalar/LoopStrengthReduce.cpp
@@ -149,7 +149,8 @@ DeleteTriviallyDeadInstructions(std::set<Instruction*> &Insts) {
       for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i)
         if (Instruction *U = dyn_cast<Instruction>(I->getOperand(i)))
           Insts.insert(U);
-      I->getParent()->getInstList().erase(I);
+      SE->deleteInstructionFromRecords(I);
+      I->eraseFromParent();
       Changed = true;
     }
   }
@@ -661,6 +662,7 @@ void LoopStrengthReduce::runOnLoop(Loop *L) {
             DeadInsts.insert(BO);
             // Break the cycle, then delete the PHI.
             PN->replaceAllUsesWith(UndefValue::get(PN->getType()));
+            SE->deleteInstructionFromRecords(PN);
             PN->eraseFromParent();
           }
         }