1/*
2 * Copyright (c) 1999, 2015, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25#include "precompiled.hpp"
26#include "asm/macroAssembler.hpp"
27#include "asm/macroAssembler.inline.hpp"
28#include "runtime/os.hpp"
29
30void MacroAssembler::int3() {
31  emit_int8((unsigned char)0xCC);
32}
33
34#ifndef _LP64
35//  The current scheme to accelerate access to the thread
36//  pointer is to store the current thread in the os_exception_wrapper
37//  and reference the current thread from stubs and compiled code
38//  via the FS register.  FS[0] contains a pointer to the structured
39//  exception block which is actually a stack address.  The first time
40//  we call the os exception wrapper, we calculate and store the
41//  offset from this exception block and use that offset here.
42//
43//  The last mechanism we used was problematic in that the
44//  the offset we had hard coded in the VM kept changing as Microsoft
45//  evolved the OS.
46//
47// Warning: This mechanism assumes that we only attempt to get the
48//          thread when we are nested below a call wrapper.
49//
50// movl reg, fs:[0]                        Get exeception pointer
51// movl reg, [reg + thread_ptr_offset]     Load thread
52//
53void MacroAssembler::get_thread(Register thread) {
54  prefix(FS_segment);
55  movptr(thread, ExternalAddress(NULL));
56  assert(os::win32::get_thread_ptr_offset() != 0,
57         "Thread Pointer Offset has not been initialized");
58  movl(thread, Address(thread, os::win32::get_thread_ptr_offset()));
59}
60
61// #else - use shared x86 implementation in cpu/x86/vm/macroAssembler_x86.cpp
62
63#endif
64