// Low-level functions for atomic operations: Alpha version -*- C++ -*- // Copyright (C) 1999, 2000, 2001 Free Software Foundation, Inc. // // This file is part of the GNU ISO C++ Library. This library is free // software; you can redistribute it and/or modify it under the // terms of the GNU General Public License as published by the // Free Software Foundation; either version 2, or (at your option) // any later version. // This library is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the // GNU General Public License for more details. // You should have received a copy of the GNU General Public License along // with this library; see the file COPYING. If not, write to the Free // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, // USA. // As a special exception, you may use this file as part of a free software // library without restriction. Specifically, if other files instantiate // templates or use macros or inline functions from this file, or you compile // this file and link it with other files to produce an executable, this // file does not by itself cause the resulting executable to be covered by // the GNU General Public License. This exception does not however // invalidate any other reasons why the executable file might be covered by // the GNU General Public License. #ifndef _BITS_ATOMICITY_H #define _BITS_ATOMICITY_H 1 /* @@@ With gas we can play nice .subsection games to get the non-predicted branch pointing forward. But Digital assemblers don't understand those directives. This isn't a terribly important issue, so just ignore it. */ typedef int _Atomic_word; static inline _Atomic_word __attribute__ ((__unused__)) __exchange_and_add (volatile _Atomic_word* __mem, int __val) { register int __result, __tmp; __asm__ __volatile__ ( "\n$Lxadd_%=:\n\t" "ldl_l %0,%3\n\t" "addl %0,%4,%1\n\t" "stl_c %1,%2\n\t" "beq %1,$Lxadd_%=\n\t" "mb" : "=&r"(__result), "=&r"(__tmp), "=m"(*__mem) : "m" (*__mem), "r"(__val)); return __result; } static inline void __attribute__ ((__unused__)) __atomic_add (volatile _Atomic_word* __mem, int __val) { register _Atomic_word __result; __asm__ __volatile__ ( "\n$Ladd_%=:\n\t" "ldl_l %0,%2\n\t" "addl %0,%3,%0\n\t" "stl_c %0,%1\n\t" "beq %0,$Ladd_%=\n\t" "mb" : "=&r"(__result), "=m"(*__mem) : "m" (*__mem), "r"(__val)); } #endif /* atomicity.h */