atomicity.h revision 117397
1// Low-level functions for atomic operations. 2 3// Copyright (C) 2001, 2002 Free Software Foundation, Inc. 4// 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) 9// any later version. 10 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. 15 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, 19// USA. 20 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. 29 30#ifndef _BITS_ATOMICITY_H 31#define _BITS_ATOMICITY_H 1 32 33typedef int _Atomic_word; 34 35static inline int 36__attribute__ ((__unused__)) 37__exchange_and_add (volatile _Atomic_word *__mem, int __val) 38{ 39 int __result, __tmp; 40 41 __asm__ __volatile__ 42 ("/* Inline exchange & add */\n\t" 43 "1:\n\t" 44 ".set push\n\t" 45 ".set mips2\n\t" 46 "ll %0,%3\n\t" 47 "addu %1,%4,%0\n\t" 48 "sc %1,%2\n\t" 49 ".set pop\n\t" 50 "beqz %1,1b\n\t" 51 "/* End exchange & add */" 52 : "=&r"(__result), "=&r"(__tmp), "=m"(*__mem) 53 : "m" (*__mem), "r"(__val) 54 : "memory"); 55 56 return __result; 57} 58 59static inline void 60__attribute__ ((__unused__)) 61__atomic_add (volatile _Atomic_word *__mem, int __val) 62{ 63 int __result; 64 65 __asm__ __volatile__ 66 ("/* Inline atomic add */\n\t" 67 "1:\n\t" 68 ".set push\n\t" 69 ".set mips2\n\t" 70 "ll %0,%2\n\t" 71 "addu %0,%3,%0\n\t" 72 "sc %0,%1\n\t" 73 ".set pop\n\t" 74 "beqz %0,1b\n\t" 75 "/* End atomic add */" 76 : "=&r"(__result), "=m"(*__mem) 77 : "m" (*__mem), "r"(__val) 78 : "memory"); 79} 80 81#endif /* atomicity.h */ 82