diff --git a/llvm/lib/CodeGen/LiveDebugValues.cpp b/llvm/lib/CodeGen/LiveDebugValues.cpp
index 1297273..4ff88d5 100644
--- a/llvm/lib/CodeGen/LiveDebugValues.cpp
+++ b/llvm/lib/CodeGen/LiveDebugValues.cpp
@@ -487,8 +487,7 @@
         if (OLChanged) {
           OLChanged = false;
           for (auto s : MBB->successors())
-            if (!OnPending.count(s)) {
-              OnPending.insert(s);
+            if (OnPending.insert(s).second) {
               Pending.push(BBToOrder[s]);
             }
         }