1132720Skan// Low-level functions for atomic operations: MIPS version  -*- C++ -*-
2117397Skan
3169691Skan// Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006
4169691Skan// Free Software Foundation, Inc.
5117397Skan//
6117397Skan// This file is part of the GNU ISO C++ Library.  This library is free
7117397Skan// software; you can redistribute it and/or modify it under the
8117397Skan// terms of the GNU General Public License as published by the
9117397Skan// Free Software Foundation; either version 2, or (at your option)
10117397Skan// any later version.
11117397Skan
12117397Skan// This library is distributed in the hope that it will be useful,
13117397Skan// but WITHOUT ANY WARRANTY; without even the implied warranty of
14117397Skan// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15117397Skan// GNU General Public License for more details.
16117397Skan
17117397Skan// You should have received a copy of the GNU General Public License along
18117397Skan// with this library; see the file COPYING.  If not, write to the Free
19169691Skan// Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
20117397Skan// USA.
21117397Skan
22117397Skan// As a special exception, you may use this file as part of a free software
23117397Skan// library without restriction.  Specifically, if other files instantiate
24117397Skan// templates or use macros or inline functions from this file, or you compile
25117397Skan// this file and link it with other files to produce an executable, this
26117397Skan// file does not by itself cause the resulting executable to be covered by
27117397Skan// the GNU General Public License.  This exception does not however
28117397Skan// invalidate any other reasons why the executable file might be covered by
29117397Skan// the GNU General Public License.
30117397Skan
31169691Skan#include <ext/atomicity.h>
32117397Skan
33169691Skan_GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)
34169691Skan
35169691Skan  // NB: MIPS II or above required.
36132720Skan  _Atomic_word
37132720Skan  __attribute__ ((__unused__))
38132720Skan  __exchange_and_add(volatile _Atomic_word* __mem, int __val)
39132720Skan  {
40132720Skan    _Atomic_word __result, __tmp;
41132720Skan
42132720Skan    __asm__ __volatile__
43132720Skan      ("/* Inline exchange & add */\n\t"
44132720Skan       "1:\n\t"
45132720Skan       ".set	push\n\t"
46132720Skan#if _MIPS_SIM == _ABIO32
47132720Skan       ".set	mips2\n\t"
48132720Skan#endif
49169691Skan       "ll	%0,0(%2)\n\t"
50169691Skan       "addu	%1,%3,%0\n\t"
51169691Skan       "sc	%1,0(%2)\n\t"
52132720Skan       ".set	pop\n\t"
53132720Skan       "beqz	%1,1b\n\t"
54132720Skan       "/* End exchange & add */"
55169691Skan       : "=&r"(__result), "=&r"(__tmp)
56169691Skan       : "r"(__mem), "r"(__val)
57169691Skan       :  "memory" );
58132720Skan
59132720Skan    return __result;
60132720Skan  }
61132720Skan
62132720Skan  void
63132720Skan  __attribute__ ((__unused__))
64132720Skan  __atomic_add(volatile _Atomic_word* __mem, int __val)
65132720Skan  {
66132720Skan    _Atomic_word __result;
67132720Skan
68132720Skan    __asm__ __volatile__
69132720Skan      ("/* Inline atomic add */\n\t"
70132720Skan       "1:\n\t"
71132720Skan       ".set	push\n\t"
72132720Skan#if _MIPS_SIM == _ABIO32
73132720Skan       ".set	mips2\n\t"
74132720Skan#endif
75169691Skan       "ll	%0,0(%1)\n\t"
76169691Skan       "addu	%0,%2,%0\n\t"
77169691Skan       "sc	%0,0(%1)\n\t"
78132720Skan       ".set	pop\n\t"
79132720Skan       "beqz	%0,1b\n\t"
80132720Skan       "/* End atomic add */"
81169691Skan       : "=&r"(__result)
82169691Skan       : "r"(__mem), "r"(__val)
83169691Skan       : "memory" );
84132720Skan  }
85169691Skan
86169691Skan_GLIBCXX_END_NAMESPACE
87