1 // Low-level functions for atomic operations: PA-RISC version -*- C++ -*- 2 3 // Copyright (C) 2002, 2004, 2005 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, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, 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 <ext/atomicity.h> 32 33 _GLIBCXX_BEGIN_NAMESPACE(__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 : "memory"); 66 67 result = *__mem; 68 *__mem = result + __val; 69 __asm__ __volatile__ ("stw %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 : "memory"); 90 91 *__mem += __val; 92 __asm__ __volatile__ ("stw %1,0(%0)" 93 : : "r" (&lock), "r" (tmp) : "memory"); 94 } 95 96 _GLIBCXX_END_NAMESPACE 97