diff --git a/lib/Transforms/InstCombine/InstCombineInternal.h b/lib/Transforms/InstCombine/InstCombineInternal.h
index 8c784ab1e68..fb2321df2e0 100644
--- a/lib/Transforms/InstCombine/InstCombineInternal.h
+++ b/lib/Transforms/InstCombine/InstCombineInternal.h
@@ -372,6 +372,10 @@ public:
   /// I to the worklist, replace all uses of I with the new value, then return
   /// I, so that the inst combiner will know that I was modified.
   Instruction *ReplaceInstUsesWith(Instruction &I, Value *V) {
+    // If there are no uses to replace, then we return nullptr to indicate that
+    // no changes were made to the program.
+    if (I.use_empty()) return nullptr;
+
     Worklist.AddUsersToWorkList(I); // Add all modified instrs to worklist.
 
     // If we are replacing the instruction with itself, this must be in a
diff --git a/test/Transforms/InstCombine/constant-fold-hang.ll b/test/Transforms/InstCombine/constant-fold-hang.ll
new file mode 100644
index 00000000000..2ca6b86ccc2
--- /dev/null
+++ b/test/Transforms/InstCombine/constant-fold-hang.ll
@@ -0,0 +1,14 @@
+; RUN: opt -instcombine < %s
+
+; Function Attrs: nounwind readnone ssp
+define void @mulByZero(<4 x i16> %x) #0 {
+entry:
+  %a = tail call <4 x i32> @llvm.arm.neon.vmulls.v4i32(<4 x i16> %x, <4 x i16> zeroinitializer) #2
+  ret void
+}
+
+; Function Attrs: nounwind readnone
+declare <4 x i32> @llvm.arm.neon.vmulls.v4i32(<4 x i16>, <4 x i16>) #1
+
+attributes #0 = { nounwind readnone ssp }
+attributes #1 = { nounwind readnone }