/*

 * Copyright (c) 1999, 2015, 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.hpp"

#include "asm/macroAssembler.inline.hpp"

#include "runtime/os.hpp"

void MacroAssembler::int3() {

  emit_int8((unsigned char)0xCC);

}

#ifndef _LP64

//  The current scheme to accelerate access to the thread

//  pointer is to store the current thread in the os_exception_wrapper

//  and reference the current thread from stubs and compiled code

//  via the FS register.  FS[0] contains a pointer to the structured

//  exception block which is actually a stack address.  The first time

//  we call the os exception wrapper, we calculate and store the

//  offset from this exception block and use that offset here.

//

//  The last mechanism we used was problematic in that the

//  the offset we had hard coded in the VM kept changing as Microsoft

//  evolved the OS.

//

// Warning: This mechanism assumes that we only attempt to get the

//          thread when we are nested below a call wrapper.

//

// movl reg, fs:[0]                        Get exeception pointer

// movl reg, [reg + thread_ptr_offset]     Load thread

//

void MacroAssembler::get_thread(Register thread) {

  prefix(FS_segment);

  movptr(thread, ExternalAddress(NULL));

  assert(os::win32::get_thread_ptr_offset() != 0,

         "Thread Pointer Offset has not been initialized");

  movl(thread, Address(thread, os::win32::get_thread_ptr_offset()));

}

// #else - use shared x86 implementation in cpu/x86/vm/macroAssembler_x86.cpp

#endif