don't invalidate PN, rewrite of this code is in progress anyway.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86639 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/Scalar/JumpThreading.cpp b/lib/Transforms/Scalar/JumpThreading.cpp
index 46d40ef5d1564ac6deb2dca605c79f898be2ca76..7a7f407b96b8d4d169175ddb55a9376ccfc0d76b 100644 (file)
--- a/lib/Transforms/Scalar/JumpThreading.cpp
+++ b/lib/Transforms/Scalar/JumpThreading.cpp
@@ -223,10 +223,11 @@ static void RemovePredecessorAndSimplify(BasicBlock *BB, BasicBlock *Pred,
       U = PNV;
       
       // See if we can simplify it.
-      if (Value *V = SimplifyInstruction(User, TD)) {
-        User->replaceAllUsesWith(V);
-        User->eraseFromParent();
-      }
+      if (User != PN)
+        if (Value *V = SimplifyInstruction(User, TD)) {
+          User->replaceAllUsesWith(V);
+          User->eraseFromParent();
+        }
     }
     
     PN->replaceAllUsesWith(PNV);