glibc/sysdeps/i386/i486/atomicity.h
Andreas Jaeger 41bdb6e20c Update to LGPL v2.1.
2001-07-06  Paul Eggert  <eggert@twinsun.com>

	* manual/argp.texi: Remove ignored LGPL copyright notice; it's
	not appropriate for documentation anyway.
	* manual/libc-texinfo.sh: "Library General Public License" ->
	"Lesser General Public License".

2001-07-06  Andreas Jaeger  <aj@suse.de>

	* All files under GPL/LGPL version 2: Place under LGPL version
	2.1.
2001-07-06 04:58:11 +00:00

58 lines
1.8 KiB
C

/* Low-level functions for atomic operations. ix86 version, x >= 4.
Copyright (C) 1997, 2000, 2001 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 Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; 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 uint32_t
__attribute__ ((unused))
exchange_and_add (volatile uint32_t *mem, uint32_t val)
{
register uint32_t result;
__asm__ __volatile__ ("lock; xaddl %0,%1"
: "=r" (result), "=m" (*mem) : "0" (val), "1" (*mem));
return result;
}
static inline void
__attribute__ ((unused))
atomic_add (volatile uint32_t *mem, int val)
{
__asm__ __volatile__ ("lock; addl %1,%0"
: "=m" (*mem) : "ir" (val), "0" (*mem));
}
static inline char
__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), "1" (*p), "a" (oldval));
return ret;
}
#endif /* atomicity.h */