--- old/src/share/vm/runtime/arguments.cpp	2012-12-19 15:57:25.963988644 -0800
+++ new/src/share/vm/runtime/arguments.cpp	2012-12-19 15:57:25.747226615 -0800
@@ -1517,6 +1517,22 @@
     FLAG_SET_DEFAULT(GCTimeRatio, 9);
   }
 
+#ifndef SERIALGC
+  // The following flag names have been replaced. Accept the previous
+  // name for a short while, but set the new flag to the value set
+  // by the user. New flag names take precedence though.
+  if (FLAG_IS_DEFAULT(G1NewSizePercent) && G1DefaultMinNewGenPercent > 0) {
+    FLAG_SET_CMDLINE(uintx, G1NewSizePercent, G1DefaultMinNewGenPercent);
+  }
+  if (FLAG_IS_DEFAULT(G1MaxNewSizePercent) && G1DefaultMaxNewGenPercent > 0) {
+    FLAG_SET_CMDLINE(uintx, G1MaxNewSizePercent, G1DefaultMaxNewGenPercent);
+  }
+  if (FLAG_IS_DEFAULT(G1MixedGCLiveThresholdPercent) &&
+      G1OldCSetRegionLiveThresholdPercent > 0) {
+    FLAG_SET_CMDLINE(uintx, G1MaxNewSizePercent, G1OldCSetRegionLiveThresholdPercent);
+  }
+#endif
+
   if (PrintGCDetails && Verbose) {
     tty->print_cr("MarkStackSize: %uk  MarkStackSizeMax: %uk",
       MarkStackSize / K, MarkStackSizeMax / K);