diff -r 5d25e03c3634 -r 77f7d412d0a1 hotspot/src/cpu/x86/vm/c1_CodeStubs_x86.cpp
--- a/hotspot/src/cpu/x86/vm/c1_CodeStubs_x86.cpp	Fri Jan 20 17:07:33 2012 -0800
+++ b/hotspot/src/cpu/x86/vm/c1_CodeStubs_x86.cpp	Wed Jan 25 17:40:51 2012 -0500
@@ -520,7 +520,7 @@
   __ load_klass(tmp_reg, src_reg);
 
   Address ref_type_adr(tmp_reg, instanceKlass::reference_type_offset());
-  __ cmpl(ref_type_adr, REF_NONE);
+  __ cmpb(ref_type_adr, REF_NONE);
   __ jcc(Assembler::equal, _continuation);
 
   // Is marking active?