assembler_windows_x86.cpp revision 1879:f95d63e2154a 
1/*
2 * Copyright (c) 1999, 2010, 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/assembler.hpp"
27#include "assembler_x86.inline.hpp"
28#include "runtime/os.hpp"
29#include "runtime/threadLocalStorage.hpp"
30
31
32void MacroAssembler::int3() {
33  emit_byte(0xCC);
34}
35
36#ifndef _LP64
37//  The current scheme to accelerate access to the thread
38//  pointer is to store the current thread in the os_exception_wrapper
39//  and reference the current thread from stubs and compiled code
40//  via the FS register.  FS[0] contains a pointer to the structured
41//  exception block which is actually a stack address.  The first time
42//  we call the os exception wrapper, we calculate and store the
43//  offset from this exception block and use that offset here.
44//
45//  The last mechanism we used was problematic in that the
46//  the offset we had hard coded in the VM kept changing as Microsoft
47//  evolved the OS.
48//
49// Warning: This mechanism assumes that we only attempt to get the
50//          thread when we are nested below a call wrapper.
51//
52// movl reg, fs:[0]                        Get exeception pointer
53// movl reg, [reg + thread_ptr_offset]     Load thread
54//
55void MacroAssembler::get_thread(Register thread) {
56  // can't use ExternalAddress because it can't take NULL
57  AddressLiteral null(0, relocInfo::none);
58
59  prefix(FS_segment);
60  movptr(thread, null);
61  assert(ThreadLocalStorage::get_thread_ptr_offset() != 0,
62         "Thread Pointer Offset has not been initialized");
63  movl(thread, Address(thread, ThreadLocalStorage::get_thread_ptr_offset()));
64}
65#else
66// call (Thread*)TlsGetValue(thread_index());
67void MacroAssembler::get_thread(Register thread) {
68   if (thread != rax) {
69     push(rax);
70   }
71   push(rdi);
72   push(rsi);
73   push(rdx);
74   push(rcx);
75   push(r8);
76   push(r9);
77   push(r10);
78   // XXX
79   mov(r10, rsp);
80   andq(rsp, -16);
81   push(r10);
82   push(r11);
83
84   movl(c_rarg0, ThreadLocalStorage::thread_index());
85   call(RuntimeAddress((address)TlsGetValue));
86
87   pop(r11);
88   pop(rsp);
89   pop(r10);
90   pop(r9);
91   pop(r8);
92   pop(rcx);
93   pop(rdx);
94   pop(rsi);
95   pop(rdi);
96   if (thread != rax) {
97       mov(thread, rax);
98       pop(rax);
99   }
100}
101#endif
102