diff --git a/llvm/lib/CodeGen/PostRAHazardRecognizer.cpp b/llvm/lib/CodeGen/PostRAHazardRecognizer.cpp
--- a/llvm/lib/CodeGen/PostRAHazardRecognizer.cpp
+++ b/llvm/lib/CodeGen/PostRAHazardRecognizer.cpp
@@ -76,6 +76,7 @@
     return false;
 
   // Loop over all of the basic blocks
+  bool Changed = false;
   for (auto &MBB : Fn) {
     // We do not call HazardRec->reset() here to make sure we are handling noop
     // hazards at the start of basic blocks.
@@ -85,6 +86,8 @@
       HazardRec->EmitNoops(NumPreNoops);
       TII->insertNoops(MBB, MachineBasicBlock::iterator(MI), NumPreNoops);
       NumNoops += NumPreNoops;
+      if (NumPreNoops)
+        Changed = true;
 
       HazardRec->EmitInstruction(&MI);
       if (HazardRec->atIssueLimit()) {
@@ -92,5 +95,5 @@
       }
     }
   }
-  return true;
+  return Changed;
 }