Index: llvm/lib/CodeGen/ReachingDefAnalysis.cpp
===================================================================
--- llvm/lib/CodeGen/ReachingDefAnalysis.cpp
+++ llvm/lib/CodeGen/ReachingDefAnalysis.cpp
@@ -214,10 +214,12 @@
   if (InstId < 0)
     return nullptr;
 
-  for (auto &MI : *MBB) {
-    if (InstIds.count(&MI) && InstIds.lookup(&MI) == InstId)
-      return &MI;
-  }
+  auto It = std::find_if(MBB->begin(), MBB->end(), [&](const MachineInstr &MI) {
+    return InstIds.lookup(&MI) == InstId;
+  });
+  if (It != MBB->end())
+    return &*It;
+
   return nullptr;
 }