diff --git a/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp b/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
index 98582ba..c55cf85 100644
--- a/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
+++ b/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
@@ -219,6 +219,7 @@
   CatchInfoFound.clear();
 #endif
   LiveOutRegInfo.clear();
+  VisitedBBs.clear();
   ArgDbgValues.clear();
   ByValArgFrameIndexMap.clear();
   RegFixups.clear();
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index 835aab2..9d3f5bc 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -831,6 +831,10 @@
 #ifndef NDEBUG
     CheckLineNumbers(LLVMBB);
 #endif
+
+    if (OptLevel != CodeGenOpt::None)
+      FuncInfo->VisitedBBs.insert(LLVMBB);
+
     FuncInfo->MBB = FuncInfo->MBBMap[LLVMBB];
     FuncInfo->InsertPt = FuncInfo->MBB->getFirstNonPHI();