--- old/src/cpu/x86/vm/c1_Runtime1_x86.cpp	2013-09-09 10:14:24.081332283 +0200
+++ new/src/cpu/x86/vm/c1_Runtime1_x86.cpp	2013-09-09 10:14:23.981330444 +0200
@@ -27,6 +27,7 @@
 #include "c1/c1_Defs.hpp"
 #include "c1/c1_MacroAssembler.hpp"
 #include "c1/c1_Runtime1.hpp"
+#include "gc_implementation/g1/g1SATBCardTableModRefBS.hpp"
 #include "interpreter/interpreter.hpp"
 #include "nativeInst_x86.hpp"
 #include "oops/compiledICHolder.hpp"
@@ -1746,13 +1747,17 @@
         __ leal(card_addr, __ as_Address(ArrayAddress(cardtable, index)));
 #endif
 
-        __ cmpb(Address(card_addr, 0), 0);
+        __ cmpb(Address(card_addr, 0), (int)CardTableModRefBS::g1_young_card_val());
+        __ jcc(Assembler::equal, done);
+
+        __ membar(Assembler::Membar_mask_bits(Assembler::StoreLoad));
+        __ cmpb(Address(card_addr, 0), (int)CardTableModRefBS::dirty_card_val());
         __ jcc(Assembler::equal, done);
 
         // storing region crossing non-NULL, card is clean.
         // dirty card and log.
 
-        __ movb(Address(card_addr, 0), 0);
+        __ movb(Address(card_addr, 0), (int)CardTableModRefBS::dirty_card_val());
 
         __ cmpl(queue_index, 0);
         __ jcc(Assembler::equal, runtime);