/*

 * Copyright (c) 2003-2004 Hewlett-Packard Development Company, L.P.

 *

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to deal

 * in the Software without restriction, including without limitation the rights

 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

 * copies of the Software, and to permit persons to whom the Software is

 * furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE

 * SOFTWARE.

 */

/* This file adds definitions appropriate for environments in which     */

/* volatile load of a given type has acquire semantics, and volatile    */

/* store of a given type has release semantics.  This is arguably       */

/* supposed to be true with the standard Itanium software conventions.  */

/* Empirically gcc/ia64 does some reordering of ordinary operations     */

/* around volatiles even when we think it should not.  GCC v3.3 and     */

/* earlier could reorder a volatile store with another store.  As of    */

/* March 2005, gcc pre-4 reuses some previously computed common         */

/* subexpressions across a volatile load; hence, we now add compiler    */

/* barriers for gcc.                                                    */

#ifndef AO_GCC_BARRIER

  /* TODO: Check GCC version (if workaround not needed for modern GCC). */

# if defined(__GNUC__)

#   define AO_GCC_BARRIER() AO_compiler_barrier()

# else

#   define AO_GCC_BARRIER() (void)0

# endif

#endif

AO_INLINE XCTYPE

AO_XSIZE_load_acquire(const volatile XCTYPE *addr)

{

  XCTYPE result = *addr;

  /* A normal volatile load generates an ld.acq (on IA-64).     */

  AO_GCC_BARRIER();

  return result;

}

#define AO_HAVE_XSIZE_load_acquire

AO_INLINE void

AO_XSIZE_store_release(volatile XCTYPE *addr, XCTYPE new_val)

{

  AO_GCC_BARRIER();

  /* A normal volatile store generates an st.rel (on IA-64).    */

  *addr = new_val;

}

#define AO_HAVE_XSIZE_store_release