glibc/sysdeps/powerpc/atomicity.h
Ulrich Drepper 2e92188db9 Update.
1999-06-13  Geoff Keating  <geoffk@ozemail.com.au>

	* sysdeps/powerpc/atomicity.h (exchange_and_add): Remove `volatile';
	add `memory' clobber; optimise for constant `val'.
	(atomic_add): Likewise.
	(test_and_set): Remove `volatile'; add `memory' clobber; be more
	like the original `test_and_set'.
	(compare_and_swap): Remove `volatile'; add `memory' clobber;
	optimise for constant `oldval'.
	(always_swap): Remove `volatile'; add `memory' clobber.
1999-06-13 15:38:11 +00:00

105 lines
2.5 KiB
C

/* Low-level functions for atomic operations. PowerPC version.
Copyright (C) 1997, 1998, 1999 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>
#if BROKEN_PPC_ASM_CR0
# define __ATOMICITY_INLINE /* nothing */
#else
# define __ATOMICITY_INLINE inline
#endif
static __ATOMICITY_INLINE int
__attribute__ ((unused))
exchange_and_add (volatile uint32_t *mem, int val)
{
int tmp, result;
__asm__ ("\
0: lwarx %0,0,%2
add%I3 %1,%0,%3
stwcx. %1,0,%2
bne- 0b
" : "=&b"(result), "=&r"(tmp) : "r" (mem), "Ir"(val) : "cr0", "memory");
return result;
}
static __ATOMICITY_INLINE void
__attribute__ ((unused))
atomic_add (volatile uint32_t *mem, int val)
{
int tmp;
__asm__ ("\
0: lwarx %0,0,%1
add%I2 %0,%0,%2
stwcx. %0,0,%1
bne- 0b
" : "=&b"(tmp) : "r" (mem), "Ir"(val) : "cr0", "memory");
}
static __ATOMICITY_INLINE int
__attribute__ ((unused))
compare_and_swap (volatile long int *p, long int oldval, long int newval)
{
int result;
__asm__ ("\
0: lwarx %0,0,%1
sub%I2c. %0,%0,%2
cntlzw %0,%0
bne- 1f
stwcx. %3,0,%1
bne- 0b
1:
" : "=&b"(result) : "r"(p), "Ir"(oldval), "r"(newval) : "cr0", "memory");
return result >> 5;
}
static __ATOMICITY_INLINE long int
__attribute__ ((unused))
always_swap (volatile long int *p, long int newval)
{
long int result;
__asm__ ("\
0: lwarx %0,0,%1
stwcx. %2,0,%1
bne- 0b
" : "=&r"(result) : "r"(p), "r"(newval) : "cr0", "memory");
return result;
}
static __ATOMICITY_INLINE int
__attribute__ ((unused))
test_and_set (volatile long int *p, long int newval)
{
int result;
__asm__ ("\
0: lwarx %0,0,%1
cmpwi %0,0
bne- 1f
stwcx. %2,0,%1
bne- 0b
1:
" : "=&r"(result) : "r"(p), "r"(newval) : "cr0", "memory");
return result;
}
#endif /* atomicity.h */