/*
* Copyright (c) 2012 Adam Hraska
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/** @addtogroup libc
* @{
*/
/** @file
*/
#ifndef _LIBC_COMPILER_BARRIER_H_
#define _LIBC_COMPILER_BARRIER_H_
#include <stdatomic.h>
static inline void compiler_barrier(void)
{
atomic_signal_fence(memory_order_seq_cst);
}
static inline void memory_barrier(void)
{
atomic_thread_fence(memory_order_seq_cst);
}
static inline void read_barrier(void)
{
atomic_thread_fence(memory_order_acquire);
}
static inline void write_barrier(void)
{
atomic_thread_fence(memory_order_release);
}
/** Forces the compiler to access (ie load/store) the variable only once. */
#define ACCESS_ONCE(var) (*((volatile typeof(var)*)&(var)))
#endif /* _LIBC_COMPILER_BARRIER_H_ */