Index: llvm/trunk/lib/Transforms/Vectorize/LoopVectorize.cpp
===================================================================
--- llvm/trunk/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ llvm/trunk/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -4859,7 +4859,7 @@
   // out of scope. It ensures a uniform instruction will only be used
   // by uniform instructions or out of scope instructions.
   unsigned idx = 0;
-  do {
+  while (idx != Worklist.size()) {
     Instruction *I = Worklist[idx++];
 
     for (auto OV : I->operand_values()) {
@@ -4873,7 +4873,7 @@
         DEBUG(dbgs() << "LV: Found uniform instruction: " << *OI << "\n");
       }
     }
-  } while (idx != Worklist.size());
+  }
 
   // For an instruction to be added into Worklist above, all its users inside
   // the current loop should be already added into Worklist. This condition
Index: llvm/trunk/test/Transforms/LoopVectorize/2016-07-27-loop-vec.ll
===================================================================
--- llvm/trunk/test/Transforms/LoopVectorize/2016-07-27-loop-vec.ll
+++ llvm/trunk/test/Transforms/LoopVectorize/2016-07-27-loop-vec.ll
@@ -0,0 +1,19 @@
+; RUN: opt < %s -loop-vectorize -S
+
+define void @foo() local_unnamed_addr {
+entry:
+  %exitcond = icmp eq i64 3, 3
+  br label %for.body
+
+for.body:                                         ; preds = %entry
+  %i.05 = phi i64 [ %inc, %for.body ], [ 0, %entry ]
+  %total1 = add nsw i64 %i.05, 3
+  %inc = add nuw nsw i64 %i.05, 1
+  br i1 %exitcond, label %for.end, label %for.body, !llvm.loop !0
+
+for.end:                                          ; preds = %for.body
+  ret void
+}
+
+!0 = distinct !{!0, !1}
+!1 = !{!"llvm.loop.vectorize.enable", i1 true}