/*

 * Copyright 1999-2003 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 *

 */

#include "incls/_precompiled.incl"

#include "incls/_assembler_windows_x86_32.cpp.incl"

void MacroAssembler::int3() {

  emit_byte(0xCC);

}

//  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) {

  // can't use ExternalAddress because it can't take NULL

  AddressLiteral null(0, relocInfo::none);

  prefix(FS_segment);

  movptr(thread, null);

  assert(ThreadLocalStorage::get_thread_ptr_offset() != 0,

         "Thread Pointer Offset has not been initialized");

  movl(thread, Address(thread, ThreadLocalStorage::get_thread_ptr_offset()));

}

bool MacroAssembler::needs_explicit_null_check(int offset) {

  return offset < 0 || (int)os::vm_page_size() <= offset;

}