1 // Low-level functions for atomic operations: x86, x >= 4 version -*- C++ -*-
3 // Copyright (C) 1999, 2000, 2001 Free Software Foundation, Inc.
5 // This file is part of the GNU ISO C++ Library. This library is free
6 // software; you can redistribute it and/or modify it under the
7 // terms of the GNU General Public License as published by the
8 // Free Software Foundation; either version 2, or (at your option)
11 // This library is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 // GNU General Public License for more details.
16 // You should have received a copy of the GNU General Public License along
17 // with this library; see the file COPYING. If not, write to the Free
18 // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
21 // As a special exception, you may use this file as part of a free software
22 // library without restriction. Specifically, if other files instantiate
23 // templates or use macros or inline functions from this file, or you compile
24 // this file and link it with other files to produce an executable, this
25 // file does not by itself cause the resulting executable to be covered by
26 // the GNU General Public License. This exception does not however
27 // invalidate any other reasons why the executable file might be covered by
28 // the GNU General Public License.
30 #ifndef _BITS_ATOMICITY_H
31 #define _BITS_ATOMICITY_H 1
33 typedef int _Atomic_word
;
35 static inline _Atomic_word
36 __attribute__ ((__unused__
))
37 __exchange_and_add (volatile _Atomic_word
*__mem
, int __val
)
39 register _Atomic_word __result
;
40 __asm__
__volatile__ ("lock; xaddl %0,%2"
42 : "0" (__val
), "m" (*__mem
)
48 __attribute__ ((__unused__
))
49 __atomic_add (volatile _Atomic_word
* __mem
, int __val
)
51 __asm__
__volatile__ ("lock; addl %0,%1"
52 : : "ir" (__val
), "m" (*__mem
) : "memory");
55 #endif /* atomicity.h */