view src/os_cpu/windows_x86/vm/assembler_windows_x86.cpp @ 453:c96030fff130

6684579: SoftReference processing can be made more efficient Summary: For current soft-ref clearing policies, we can decide at marking time if a soft-reference will definitely not be cleared, postponing the decision of whether it will definitely be cleared to the final reference processing phase. This can be especially beneficial in the case of concurrent collectors where the marking is usually concurrent but reference processing is usually not. Reviewed-by: jmasa
author ysr
date Thu, 20 Nov 2008 16:56:09 -0800
parents dc7f315e41f7
children c18cbe5936b8
line wrap: on
line source

/*
 * Copyright 1999-2008 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.cpp.incl"


void MacroAssembler::int3() {
  emit_byte(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) {
  // 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()));
}
#else
// call (Thread*)TlsGetValue(thread_index());
void MacroAssembler::get_thread(Register thread) {
   if (thread != rax) {
     push(rax);
   }
   push(rdi);
   push(rsi);
   push(rdx);
   push(rcx);
   push(r8);
   push(r9);
   push(r10);
   // XXX
   mov(r10, rsp);
   andq(rsp, -16);
   push(r10);
   push(r11);

   movl(c_rarg0, ThreadLocalStorage::thread_index());
   call(RuntimeAddress((address)TlsGetValue));

   pop(r11);
   pop(rsp);
   pop(r10);
   pop(r9);
   pop(r8);
   pop(rcx);
   pop(rdx);
   pop(rsi);
   pop(rdi);
   if (thread != rax) {
       mov(thread, rax);
       pop(rax);
   }
}
#endif