--- a/hotspot/src/cpu/x86/vm/c1_CodeStubs_x86.cpp	Fri Apr 08 14:53:16 2011 -0700
+++ b/hotspot/src/cpu/x86/vm/c1_CodeStubs_x86.cpp	Wed Apr 13 17:56:43 2011 -0700
@@ -523,7 +523,7 @@
 
   // Is marking active?
   assert(thread()->is_register(), "precondition");
-  Register thread_reg = thread()->as_register();
+  Register thread_reg = NOT_LP64(thread()->as_register()) LP64_ONLY(thread()->as_register_lo());
 
   Address in_progress(thread_reg, in_bytes(JavaThread::satb_mark_queue_offset() +
                                        PtrQueue::byte_offset_of_active()));