diff --git a/src/hotspot/cpu/x86/gc/shared/cardTableModRefBSCodeGen_x86.cpp b/src/hotspot/cpu/x86/gc/shared/cardTableModRefBSCodeGen_x86.cpp
new file mode 100644
index 0000000..83f95ff
--- /dev/null
+++ b/src/hotspot/cpu/x86/gc/shared/cardTableModRefBSCodeGen_x86.cpp
@@ -0,0 +1,86 @@
+/*
+ * Copyright (c) 2018, Oracle and/or its affiliates. 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#include "precompiled.hpp"
+#include "asm/macroAssembler.inline.hpp"
+#include "gc/shared/barrierSet.hpp"
+#include "gc/shared/cardTable.hpp"
+#include "gc/shared/cardTableModRefBS.hpp"
+#include "gc/shared/cardTableModRefBSCodeGen.hpp"
+#include "gc/shared/collectedHeap.hpp"
+
+#define __ masm->
+
+#ifdef PRODUCT
+#define BLOCK_COMMENT(str) /* nothing */
+#else
+#define BLOCK_COMMENT(str) __ block_comment(str)
+#endif
+
+#define BIND(label) bind(label); BLOCK_COMMENT(#label ":")
+
+#define TIMES_OOP (UseCompressedOops ? Address::times_4 : Address::times_8)
+
+void CardTableModRefBSCodeGen::gen_write_ref_array_post_barrier(MacroAssembler* masm, DecoratorSet decorators, Register addr, Register count, Register tmp) {
+  BarrierSet *bs = Universe::heap()->barrier_set();
+  CardTableModRefBS* ctbs = barrier_set_cast<CardTableModRefBS>(bs);
+  CardTable* ct = ctbs->card_table();
+  assert(sizeof(*ct->byte_map_base()) == sizeof(jbyte), "adjust this code");
+  intptr_t disp = (intptr_t) ct->byte_map_base();
+
+  Label L_loop, L_done;
+  const Register end = count;
+  assert_different_registers(addr, end);
+
+  __ testl(count, count);
+  __ jcc(Assembler::zero, L_done); // zero count - nothing to do
+
+
+#ifdef _LP64
+  __ leaq(end, Address(addr, count, TIMES_OOP, 0));  // end == addr+count*oop_size
+  __ subptr(end, BytesPerHeapOop); // end - 1 to make inclusive
+  __ shrptr(addr, CardTable::card_shift);
+  __ shrptr(end, CardTable::card_shift);
+  __ subptr(end, addr); // end --> cards count
+
+  __ mov64(tmp, disp);
+  __ addptr(addr, tmp);
+__ BIND(L_loop);
+  __ movb(Address(addr, count, Address::times_1), 0);
+  __ decrement(count);
+  __ jcc(Assembler::greaterEqual, L_loop);
+#else
+  __ lea(end,  Address(addr, count, Address::times_ptr, -wordSize));
+  __ shrptr(addr, CardTable::card_shift);
+  __ shrptr(end,   CardTable::card_shift);
+  __ subptr(end, addr); // end --> count
+__ BIND(L_loop);
+  Address cardtable(addr, count, Address::times_1, disp);
+  __ movb(cardtable, 0);
+  __ decrement(count);
+  __ jcc(Assembler::greaterEqual, L_loop);
+#endif
+
+__ BIND(L_done);
+}