Index: lib/Transforms/Utils/Local.cpp
===================================================================
--- lib/Transforms/Utils/Local.cpp
+++ lib/Transforms/Utils/Local.cpp
@@ -621,9 +621,11 @@
     DestBB->moveAfter(PredBB);
 
   if (DT) {
-    BasicBlock *PredBBIDom = DT->getNode(PredBB)->getIDom()->getBlock();
-    DT->changeImmediateDominator(DestBB, PredBBIDom);
-    DT->eraseNode(PredBB);
+    if (DomTreeNode *DTN = DT->getNode(PredBB)) {
+      BasicBlock *PredBBIDom = DTN->getIDom()->getBlock();
+      DT->changeImmediateDominator(DestBB, PredBBIDom);
+      DT->eraseNode(PredBB);
+    }
   }
   // Nuke BB.
   PredBB->eraseFromParent();