--- a/src/share/vm/runtime/arguments.cpp	Thu Feb 11 10:48:10 2010 -0800
+++ b/src/share/vm/runtime/arguments.cpp	Fri Feb 12 15:27:36 2010 -0800
@@ -1,5 +1,5 @@
 /*
- * Copyright 1997-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 1997-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -2524,6 +2524,9 @@
     SOLARIS_ONLY(FLAG_SET_DEFAULT(UseISM, false));
   }
 
+  // Tiered compilation is undefined with C1.
+  TieredCompilation = false;
+
 #else
   if (!FLAG_IS_DEFAULT(OptoLoopAlignment) && FLAG_IS_DEFAULT(MaxLoopPad)) {
     FLAG_SET_DEFAULT(MaxLoopPad, OptoLoopAlignment-1);