Index: lib/Transforms/Vectorize/LoopVectorize.cpp
===================================================================
--- lib/Transforms/Vectorize/LoopVectorize.cpp
+++ lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -1144,17 +1144,20 @@
 
 static void emitMissedWarning(Function *F, Loop *L,
                               const LoopVectorizeHints &LH) {
+  DebugLoc DL = L->getStartLoc();
+  if (!DL)
+    return;
   emitOptimizationRemarkMissed(F->getContext(), DEBUG_TYPE, *F,
-                               L->getStartLoc(), LH.emitRemark());
+                               DL, LH.emitRemark());
 
   if (LH.getForce() == LoopVectorizeHints::FK_Enabled) {
     if (LH.getWidth() != 1)
       emitLoopVectorizeWarning(
-          F->getContext(), *F, L->getStartLoc(),
+          F->getContext(), *F, DL,
           "failed explicitly specified loop vectorization");
     else if (LH.getInterleave() != 1)
       emitLoopInterleaveWarning(
-          F->getContext(), *F, L->getStartLoc(),
+          F->getContext(), *F, DL,
           "failed explicitly specified loop interleaving");
   }
 }