| // Low-level type for atomic operations -*- C++ -*- |
| |
| // Copyright (C) 2004 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 _GLIBCXX_ATOMIC_WORD_H |
| #define _GLIBCXX_ATOMIC_WORD_H 1 |
| |
| #include <cxxabi.h> |
| |
| typedef int _Atomic_word; |
| |
| namespace __gnu_cxx |
| { |
| // Test the first byte of __g and ensure that no loads are hoisted across |
| // the test. |
| inline bool |
| __test_and_acquire (__cxxabiv1::__guard *__g) |
| { |
| unsigned char __c; |
| unsigned char *__p = reinterpret_cast<unsigned char *>(__g); |
| // ldN.acq is a load with an implied hoist barrier. |
| // would ld8+mask be faster than just doing an ld1? |
| __asm __volatile ("ld1.acq %0 = %1" : "=r"(__c) : "m"(*__p) : "memory"); |
| return __c != 0; |
| } |
| |
| // Set the first byte of __g to 1 and ensure that no stores are sunk |
| // across the store. |
| inline void |
| __set_and_release (__cxxabiv1::__guard *__g) |
| { |
| unsigned char *__p = reinterpret_cast<unsigned char *>(__g); |
| // stN.rel is a store with an implied sink barrier. |
| // could load word, set flag, and CAS it back |
| __asm __volatile ("st1.rel %0 = %1" : "=m"(*__p) : "r"(1) : "memory"); |
| } |
| |
| // We don't define the _BARRIER macros on ia64 because the barriers are |
| // included in the test and set, above. |
| #define _GLIBCXX_GUARD_TEST_AND_ACQUIRE(G) __gnu_cxx::__test_and_acquire (G) |
| #define _GLIBCXX_GUARD_SET_AND_RELEASE(G) __gnu_cxx::__set_and_release (G) |
| } |
| |
| #endif |
