Index: cfe/trunk/lib/CodeGen/CGObjC.cpp
===================================================================
--- cfe/trunk/lib/CodeGen/CGObjC.cpp
+++ cfe/trunk/lib/CodeGen/CGObjC.cpp
@@ -2161,14 +2161,10 @@
     // with this marker yet, so leave a breadcrumb for the ARC
     // optimizer to pick up.
     } else {
-      llvm::NamedMDNode *metadata =
-        CGF.CGM.getModule().getOrInsertNamedMetadata(
-                            "clang.arc.retainAutoreleasedReturnValueMarker");
-      assert(metadata->getNumOperands() <= 1);
-      if (metadata->getNumOperands() == 0) {
-        auto &ctx = CGF.getLLVMContext();
-        metadata->addOperand(llvm::MDNode::get(ctx,
-                                     llvm::MDString::get(ctx, assembly)));
+      const char *markerKey = "clang.arc.retainAutoreleasedReturnValueMarker";
+      if (!CGF.CGM.getModule().getModuleFlag(markerKey)) {
+        auto *str = llvm::MDString::get(CGF.getLLVMContext(), assembly);
+        CGF.CGM.getModule().addModuleFlag(llvm::Module::Error, markerKey, str);
       }
     }
   }
Index: cfe/trunk/test/CodeGenObjC/arc-unsafeclaim.m
===================================================================
--- cfe/trunk/test/CodeGenObjC/arc-unsafeclaim.m
+++ cfe/trunk/test/CodeGenObjC/arc-unsafeclaim.m
@@ -231,4 +231,5 @@
 
 // This is always at the end of the module.
 
-// CHECK-OPTIMIZED: !clang.arc.retainAutoreleasedReturnValueMarker = !{!0}
+// CHECK-OPTIMIZED: !llvm.module.flags = !{!0,
+// CHECK-OPTIMIZED: !0 = !{i32 1, !"clang.arc.retainAutoreleasedReturnValueMarker", !"mov{{.*}}marker for objc_retainAutoreleaseReturnValue"}