1// Low-level functions for atomic operations: MIPS version  -*- C++ -*-
2
3// Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006
4// Free Software Foundation, Inc.
5//
6// This file is part of the GNU ISO C++ Library.  This library is free
7// software; you can redistribute it and/or modify it under the
8// terms of the GNU General Public License as published by the
9// Free Software Foundation; either version 2, or (at your option)
10// any later version.
11
12// This library is distributed in the hope that it will be useful,
13// but WITHOUT ANY WARRANTY; without even the implied warranty of
14// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15// GNU General Public License for more details.
16
17// You should have received a copy of the GNU General Public License along
18// with this library; see the file COPYING.  If not, write to the Free
19// Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
20// USA.
21
22// As a special exception, you may use this file as part of a free software
23// library without restriction.  Specifically, if other files instantiate
24// templates or use macros or inline functions from this file, or you compile
25// this file and link it with other files to produce an executable, this
26// file does not by itself cause the resulting executable to be covered by
27// the GNU General Public License.  This exception does not however
28// invalidate any other reasons why the executable file might be covered by
29// the GNU General Public License.
30
31#include <ext/atomicity.h>
32
33_GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)
34
35  // NB: MIPS II or above required.
36  _Atomic_word
37  __attribute__ ((__unused__))
38  __exchange_and_add(volatile _Atomic_word* __mem, int __val)
39  {
40    _Atomic_word __result, __tmp;
41
42    __asm__ __volatile__
43      ("/* Inline exchange & add */\n\t"
44       "1:\n\t"
45       ".set	push\n\t"
46#if _MIPS_SIM == _ABIO32
47       ".set	mips2\n\t"
48#endif
49       "ll	%0,0(%2)\n\t"
50       "addu	%1,%3,%0\n\t"
51       "sc	%1,0(%2)\n\t"
52       ".set	pop\n\t"
53       "beqz	%1,1b\n\t"
54       "/* End exchange & add */"
55       : "=&r"(__result), "=&r"(__tmp)
56       : "r"(__mem), "r"(__val)
57       :  "memory" );
58
59    return __result;
60  }
61
62  void
63  __attribute__ ((__unused__))
64  __atomic_add(volatile _Atomic_word* __mem, int __val)
65  {
66    _Atomic_word __result;
67
68    __asm__ __volatile__
69      ("/* Inline atomic add */\n\t"
70       "1:\n\t"
71       ".set	push\n\t"
72#if _MIPS_SIM == _ABIO32
73       ".set	mips2\n\t"
74#endif
75       "ll	%0,0(%1)\n\t"
76       "addu	%0,%2,%0\n\t"
77       "sc	%0,0(%1)\n\t"
78       ".set	pop\n\t"
79       "beqz	%0,1b\n\t"
80       "/* End atomic add */"
81       : "=&r"(__result)
82       : "r"(__mem), "r"(__val)
83       : "memory" );
84  }
85
86_GLIBCXX_END_NAMESPACE
87