1*404b540aSrobert // Low-level type for atomic operations -*- C++ -*- 2*404b540aSrobert 3*404b540aSrobert // Copyright (C) 2004 Free Software Foundation, Inc. 4*404b540aSrobert // 5*404b540aSrobert // This file is part of the GNU ISO C++ Library. This library is free 6*404b540aSrobert // software; you can redistribute it and/or modify it under the 7*404b540aSrobert // terms of the GNU General Public License as published by the 8*404b540aSrobert // Free Software Foundation; either version 2, or (at your option) 9*404b540aSrobert // any later version. 10*404b540aSrobert 11*404b540aSrobert // This library is distributed in the hope that it will be useful, 12*404b540aSrobert // but WITHOUT ANY WARRANTY; without even the implied warranty of 13*404b540aSrobert // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14*404b540aSrobert // GNU General Public License for more details. 15*404b540aSrobert 16*404b540aSrobert // You should have received a copy of the GNU General Public License along 17*404b540aSrobert // with this library; see the file COPYING. If not, write to the Free 18*404b540aSrobert // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, 19*404b540aSrobert // USA. 20*404b540aSrobert 21*404b540aSrobert // As a special exception, you may use this file as part of a free software 22*404b540aSrobert // library without restriction. Specifically, if other files instantiate 23*404b540aSrobert // templates or use macros or inline functions from this file, or you compile 24*404b540aSrobert // this file and link it with other files to produce an executable, this 25*404b540aSrobert // file does not by itself cause the resulting executable to be covered by 26*404b540aSrobert // the GNU General Public License. This exception does not however 27*404b540aSrobert // invalidate any other reasons why the executable file might be covered by 28*404b540aSrobert // the GNU General Public License. 29*404b540aSrobert 30*404b540aSrobert /** @file atomic_word.h 31*404b540aSrobert * This file is a GNU extension to the Standard C++ Library. 32*404b540aSrobert */ 33*404b540aSrobert 34*404b540aSrobert #ifndef _GLIBCXX_ATOMIC_WORD_H 35*404b540aSrobert #define _GLIBCXX_ATOMIC_WORD_H 1 36*404b540aSrobert 37*404b540aSrobert typedef int _Atomic_word; 38*404b540aSrobert 39*404b540aSrobert // Define these two macros using the appropriate memory barrier for the target. 40*404b540aSrobert // The commented out versions below are the defaults. 41*404b540aSrobert // See ia64/atomic_word.h for an alternative approach. 42*404b540aSrobert 43*404b540aSrobert // This one prevents loads from being hoisted across the barrier; 44*404b540aSrobert // in other words, this is a Load-Load acquire barrier. 45*404b540aSrobert // This is necessary iff TARGET_RELAXED_ORDERING is defined in tm.h. 46*404b540aSrobert // #define _GLIBCXX_READ_MEM_BARRIER __asm __volatile ("":::"memory") 47*404b540aSrobert 48*404b540aSrobert // This one prevents stores from being sunk across the barrier; in other 49*404b540aSrobert // words, a Store-Store release barrier. 50*404b540aSrobert // #define _GLIBCXX_WRITE_MEM_BARRIER __asm __volatile ("":::"memory") 51*404b540aSrobert 52*404b540aSrobert #endif 53