atomicity.h revision 132720
1// Low-level functions for atomic operations: PA-RISC version -*- C++ -*- 2 3// Copyright (C) 2002, 2004 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#include <bits/c++config.h> 31#include <bits/atomicity.h> 32 33namespace __gnu_cxx 34{ 35 template<int _Inst> 36 struct _Atomicity_lock 37 { 38 static volatile int _S_atomicity_lock; 39 }; 40 41 template<int _Inst> 42 volatile int 43 _Atomicity_lock<_Inst>::_S_atomicity_lock __attribute__ ((aligned (16))) = 1; 44 45 // Because of the lack of weak support when using the hpux som 46 // linker, we explicitly instantiate the atomicity lock. 47 template volatile int _Atomicity_lock<0>::_S_atomicity_lock; 48 49 int 50 __attribute__ ((__unused__)) 51 __exchange_and_add(volatile _Atomic_word* __mem, int __val) 52 { 53 _Atomic_word result; 54 int tmp; 55 volatile int& lock = _Atomicity_lock<0>::_S_atomicity_lock; 56 57 __asm__ __volatile__ ("ldcw 0(%1),%0\n\t" 58 "cmpib,<>,n 0,%0,.+20\n\t" 59 "ldw 0(%1),%0\n\t" 60 "cmpib,= 0,%0,.-4\n\t" 61 "nop\n\t" 62 "b,n .-20" 63 : "=&r" (tmp) 64 : "r" (&lock)); 65 66 result = *__mem; 67 *__mem = result + __val; 68 /* Reset lock with PA 2.0 "ordered" store. */ 69 __asm__ __volatile__ ("stw,ma %1,0(%0)" 70 : : "r" (&lock), "r" (tmp) : "memory"); 71 return result; 72 } 73 74 void 75 __attribute__ ((__unused__)) 76 __atomic_add(volatile _Atomic_word* __mem, int __val) 77 { 78 int tmp; 79 volatile int& lock = _Atomicity_lock<0>::_S_atomicity_lock; 80 81 __asm__ __volatile__ ("ldcw 0(%1),%0\n\t" 82 "cmpib,<>,n 0,%0,.+20\n\t" 83 "ldw 0(%1),%0\n\t" 84 "cmpib,= 0,%0,.-4\n\t" 85 "nop\n\t" 86 "b,n .-20" 87 : "=&r" (tmp) 88 : "r" (&lock)); 89 90 *__mem += __val; 91 /* Reset lock with PA 2.0 "ordered" store. */ 92 __asm__ __volatile__ ("stw,ma %1,0(%0)" 93 : : "r" (&lock), "r" (tmp) : "memory"); 94 } 95} // namespace __gnu_cxx 96