1 /*
   2  * Copyright (c) 1999, 2008, 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 "incls/_precompiled.incl"
  26 #include "incls/_assembler_windows_x86.cpp.incl"
  27 
  28 
  29 void MacroAssembler::int3() {
  30   emit_byte(0xCC);
  31 }
  32 
  33 #ifndef _LP64
  34 //  The current scheme to accelerate access to the thread
  35 //  pointer is to store the current thread in the os_exception_wrapper
  36 //  and reference the current thread from stubs and compiled code
  37 //  via the FS register.  FS[0] contains a pointer to the structured
  38 //  exception block which is actually a stack address.  The first time
  39 //  we call the os exception wrapper, we calculate and store the
  40 //  offset from this exception block and use that offset here.
  41 //
  42 //  The last mechanism we used was problematic in that the
  43 //  the offset we had hard coded in the VM kept changing as Microsoft
  44 //  evolved the OS.
  45 //
  46 // Warning: This mechanism assumes that we only attempt to get the
  47 //          thread when we are nested below a call wrapper.
  48 //
  49 // movl reg, fs:[0]                        Get exeception pointer
  50 // movl reg, [reg + thread_ptr_offset]     Load thread
  51 //
  52 void MacroAssembler::get_thread(Register thread) {
  53   // can't use ExternalAddress because it can't take NULL
  54   AddressLiteral null(0, relocInfo::none);
  55 
  56   prefix(FS_segment);
  57   movptr(thread, null);
  58   assert(ThreadLocalStorage::get_thread_ptr_offset() != 0,
  59          "Thread Pointer Offset has not been initialized");
  60   movl(thread, Address(thread, ThreadLocalStorage::get_thread_ptr_offset()));
  61 }
  62 #else
  63 // call (Thread*)TlsGetValue(thread_index());
  64 void MacroAssembler::get_thread(Register thread) {
  65    if (thread != rax) {
  66      push(rax);
  67    }
  68    push(rdi);
  69    push(rsi);
  70    push(rdx);
  71    push(rcx);
  72    push(r8);
  73    push(r9);
  74    push(r10);
  75    // XXX
  76    mov(r10, rsp);
  77    andq(rsp, -16);
  78    push(r10);
  79    push(r11);
  80 
  81    movl(c_rarg0, ThreadLocalStorage::thread_index());
  82    call(RuntimeAddress((address)TlsGetValue));
  83 
  84    pop(r11);
  85    pop(rsp);
  86    pop(r10);
  87    pop(r9);
  88    pop(r8);
  89    pop(rcx);
  90    pop(rdx);
  91    pop(rsi);
  92    pop(rdi);
  93    if (thread != rax) {
  94        mov(thread, rax);
  95        pop(rax);
  96    }
  97 }
  98 #endif