fix PR6305 by handling BlockAddress in a helper function

called by jump threading.

llvm-svn: 96263

1 files changed, 11 insertions, 0 deletions

diff --git a/llvm/lib/Transforms/Utils/Local.cpp b/llvm/lib/Transforms/Utils/Local.cpp
index 7e7973ae0b7..57ad459c8e1 100644
--- a/llvm/lib/Transforms/Utils/Local.cpp
+++ b/llvm/lib/Transforms/Utils/Local.cpp
@@ -490,6 +490,17 @@ void llvm::MergeBasicBlockIntoOnlyPred(BasicBlock *DestBB, Pass *P) {
   // Splice all the instructions from PredBB to DestBB.
   PredBB->getTerminator()->eraseFromParent();
   DestBB->getInstList().splice(DestBB->begin(), PredBB->getInstList());
+
+  // Zap anything that took the address of DestBB.  Not doing this will give the
+  // address an invalid value.
+  if (DestBB->hasAddressTaken()) {
+    BlockAddress *BA = BlockAddress::get(DestBB);
+    Constant *Replacement =
+      ConstantInt::get(llvm::Type::getInt32Ty(BA->getContext()), 1);
+    BA->replaceAllUsesWith(ConstantExpr::getIntToPtr(Replacement,
+                                                     BA->getType()));
+    BA->destroyConstant();
+  }
   
   // Anything that branched to PredBB now branches to DestBB.
   PredBB->replaceAllUsesWith(DestBB);