Index: lib/CodeGen/TargetInfo.cpp
===================================================================
--- lib/CodeGen/TargetInfo.cpp
+++ lib/CodeGen/TargetInfo.cpp
@@ -2073,8 +2073,10 @@
         classify(I.getType(), Offset, FieldLo, FieldHi, isNamedArg);
         Lo = merge(Lo, FieldLo);
         Hi = merge(Hi, FieldHi);
-        if (Lo == Memory || Hi == Memory)
-          break;
+        if (Lo == Memory || Hi == Memory) {
+          postMerge(Size, Lo, Hi);
+          return;
+        }
       }
     }
 
Index: test/CodeGenCXX/x86_64-arguments.cpp
===================================================================
--- test/CodeGenCXX/x86_64-arguments.cpp
+++ test/CodeGenCXX/x86_64-arguments.cpp
@@ -196,3 +196,19 @@
     return sret;
   }
 }
+
+namespace test10 {
+#pragma pack(1)
+struct BasePacked {
+  char one;
+  short two;
+};
+#pragma pack()
+struct DerivedPacked : public BasePacked {
+  int three;
+};
+// CHECK-LABEL: define i32 @_ZN6test1020FuncForDerivedPackedENS_13DerivedPackedE({{.*}}* byval align 8
+int FuncForDerivedPacked(DerivedPacked d) {
+  return d.three;
+}
+}