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/* Low-level functions for atomitc operations. ix86 version, x >= 4.
Copyright (C) 1997 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#ifndef _ATOMICITY_H
#define _ATOMICITY_H 1
#include <inttypes.h>
static inline int
__attribute__ ((unused))
exchange_and_add (volatile uint32_t *mem, int val)
{
register int result;
__asm__ __volatile__ ("lock; xaddl %0,%1"
: "=r" (result) : "0" (val), "m" (*mem) : "memory");
return result;
}
static inline void
__attribute__ ((unused))
atomic_add (volatile uint32_t *mem, int val)
{
__asm__ __volatile__ ("lock; addl %0,%1"
: : "ir" (val), "m" (*mem) : "memory");
}
static inline int
__attribute__ ((unused))
compare_and_swap (volatile long int *p, long int oldval, long int newval)
{
char ret;
long int readval;
__asm__ __volatile__ ("lock; cmpxchgl %3, %1; sete %0"
: "=q" (ret), "=m" (*p), "=a" (readval)
: "r" (newval), "m" (*p), "a" (oldval));
return ret;
}
#endif /* atomicity.h */
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