--- old/src/cpu/x86/vm/c1_LIRAssembler_x86.cpp	2014-04-02 13:58:43.000000000 -0700
+++ new/src/cpu/x86/vm/c1_LIRAssembler_x86.cpp	2014-04-02 13:58:43.000000000 -0700
@@ -799,7 +799,13 @@
         if (UseCompressedOops && !wide) {
           __ movl(as_Address(addr), (int32_t)NULL_WORD);
         } else {
+#ifdef _LP64
+          __ xorptr(rscratch1, rscratch1);
+          null_check_here = code_offset();
+          __ movptr(as_Address(addr), rscratch1);
+#else
           __ movptr(as_Address(addr), NULL_WORD);
+#endif
         }
       } else {
         if (is_literal_address(addr)) {