diff --git a/llvm/include/llvm/ADT/SCCIterator.h b/llvm/include/llvm/ADT/SCCIterator.h
--- a/llvm/include/llvm/ADT/SCCIterator.h
+++ b/llvm/include/llvm/ADT/SCCIterator.h
@@ -348,9 +348,14 @@
     NodeInfoMap[Edge->Target].Visited = false;
 
   std::queue<NodeType *> Queue;
-  for (auto &Node : NodeInfoMap)
-    if (Node.second.Visited)
-      Queue.push(Node.first);
+  // Initialze the queue with MST roots. Note that walking through SortedEdges
+  // instead of NodeInfoMap ensures an ordered deterministic push.
+  for (auto *Edge : SortedEdges) {
+    if (NodeInfoMap[Edge->Source].Visited) {
+      Queue.push(Edge->Source);
+      NodeInfoMap[Edge->Source].Visited = false;
+    }
+  }
 
   while (!Queue.empty()) {
     auto *Node = Queue.front();