mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-13 23:00:22 +00:00
93dceeb10e
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.
105 lines
2.5 KiB
C
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 */
|