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53 lines
1.8 KiB
C++
53 lines
1.8 KiB
C++
// Low-level functions for atomic operations: x86, x >= 4 version -*- C++ -*-
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// Copyright (C) 1999-2015 Free Software Foundation, Inc.
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//
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// This file is part of the GNU ISO C++ Library. This library is free
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// software; you can redistribute it and/or modify it under the
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// terms of the GNU General Public License as published by the
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// Free Software Foundation; either version 3, or (at your option)
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// any later version.
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// This library is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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// Under Section 7 of GPL version 3, you are granted additional
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// permissions described in the GCC Runtime Library Exception, version
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// 3.1, as published by the Free Software Foundation.
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// You should have received a copy of the GNU General Public License and
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// a copy of the GCC Runtime Library Exception along with this program;
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// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
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// <http://www.gnu.org/licenses/>.
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#include <ext/atomicity.h>
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namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
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{
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_GLIBCXX_BEGIN_NAMESPACE_VERSION
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_Atomic_word
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__attribute__ ((__unused__))
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__exchange_and_add(volatile _Atomic_word* __mem, int __val) throw ()
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{
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register _Atomic_word __result;
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__asm__ __volatile__ ("lock; xadd{l} {%0,%1|%1,%0}"
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: "=r" (__result), "=m" (*__mem)
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: "0" (__val), "m" (*__mem));
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return __result;
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}
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void
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__attribute__ ((__unused__))
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__atomic_add(volatile _Atomic_word* __mem, int __val) throw ()
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{
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__asm__ __volatile__ ("lock; add{l} {%1,%0|%0,%1}"
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: "=m" (*__mem) : "ir" (__val), "m" (*__mem));
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}
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_GLIBCXX_END_NAMESPACE_VERSION
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} // namespace
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