--- old/src/share/vm/runtime/globals_extension.hpp	2016-03-15 14:24:02.086791825 +0100
+++ new/src/share/vm/runtime/globals_extension.hpp	2016-03-15 14:24:01.970786952 +0100
@@ -290,6 +290,12 @@
 
 #define FLAG_SET_CMDLINE(type, name, value) (CommandLineFlagsEx::type##AtPut(FLAG_MEMBER_WITH_TYPE(name,type), (type)(value), Flag::COMMAND_LINE))
 #define FLAG_SET_ERGO(type, name, value)    (CommandLineFlagsEx::type##AtPut(FLAG_MEMBER_WITH_TYPE(name,type), (type)(value), Flag::ERGONOMIC))
+#define FLAG_SET_ERGO_IF_DEFAULT(type, name, value) \
+  do {                                              \
+    if (FLAG_IS_DEFAULT(name)) {                    \
+      FLAG_SET_ERGO(type, name, value);             \
+    }                                               \
+  } while (0)
 
 // Can't put the following in CommandLineFlags because
 // of a circular dependency on the enum definition.