Manually notify ScalarEvolution before making an operand replacement, since
it can't currently observe such changes automatically.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100186 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/IndVarSimplify.cpp b/lib/Transforms/Scalar/IndVarSimplify.cpp
index 988a4cb..2722a66 100644
--- a/lib/Transforms/Scalar/IndVarSimplify.cpp
+++ b/lib/Transforms/Scalar/IndVarSimplify.cpp
@@ -510,6 +510,13 @@
// Now expand it into actual Instructions and patch it into place.
Value *NewVal = Rewriter.expandCodeFor(AR, UseTy, InsertPt);
+ // Inform ScalarEvolution that this value is changing. The change doesn't
+ // affect its value, but it does potentially affect which use lists the
+ // value will be on after the replacement, which affects ScalarEvolution's
+ // ability to walk use lists and drop dangling pointers when a value is
+ // deleted.
+ SE->forgetValue(User);
+
// Patch the new value into place.
if (Op->hasName())
NewVal->takeName(Op);