--- old/src/hotspot/cpu/x86/x86_64.ad	2018-10-31 14:22:34.392959269 +0100
+++ new/src/hotspot/cpu/x86/x86_64.ad	2018-10-31 14:22:34.260959374 +0100
@@ -1,5 +1,5 @@
 //
-// Copyright (c) 2003, 2017, Oracle and/or its affiliates. All rights reserved.
+// Copyright (c) 2003, 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
@@ -5802,6 +5802,27 @@
 %}
 
 //----------Store Instructions-------------------------------------------------
+// Store Bit
+instruct storeZ0(memory mem, rRegI src)
+%{
+  match(Set mem (StoreZ0 mem src));
+
+  ins_cost(125);
+  format %{ "andb    $mem, $src\t# byte" %}
+  opcode(0x20);
+  ins_encode(lock_prefix, REX_breg_mem(src, mem), OpcP, reg_mem(src, mem));
+  ins_pipe(ialu_mem_reg);
+%}
+
+instruct storeZ1(memory mem, rRegI src)
+%{
+  match(Set mem (StoreZ1 mem src));
+  ins_cost(125);
+  format %{ "orb     $mem, $src\t# byte" %}
+  opcode(0x08);
+  ins_encode(lock_prefix, REX_breg_mem(src, mem), OpcP, reg_mem(src, mem));
+  ins_pipe(ialu_mem_reg);
+%}
 
 // Store Byte
 instruct storeB(memory mem, rRegI src)