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* Copyright (c) 2003 Hewlett-Packard Development Company, L.P.
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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* This file adds definitions appropriate for environments in which an AO_t
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* volatile load has acquire semantics, and an AO_t volatile store has release
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* semantics. This is arguably supposed to be true with the standard Itanium
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* software conventions.
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* Empirically gcc/ia64 does some reordering of ordinary operations around volatiles
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* even when we think it shouldn't. Gcc 3.3 and earlier could reorder a volatile store
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* with another store. As of March 2005, gcc pre-4 reused previously computed
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* common subexpressions across a volatile load.
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* Hence we now add compiler barriers for gcc.
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#if !defined(AO_GCC_BARRIER)
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# if defined(__GNUC__)
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# define AO_GCC_BARRIER() AO_compiler_barrier()
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# define AO_GCC_BARRIER()
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AO_load_acquire(volatile AO_t *p)
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/* A normal volatile load generates an ld.acq */
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#define AO_HAVE_load_acquire
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AO_store_release(volatile AO_t *p, AO_t val)
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/* A normal volatile store generates an st.rel */
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#define AO_HAVE_store_release