minix/common/lib/libc/arch/arm/atomic/atomic_dec_32.S

70 lines
2.9 KiB
ArmAsm
Raw Normal View History

/* $NetBSD: atomic_dec_32.S,v 1.2 2008/08/16 07:12:39 matt Exp $ */
/*-
* Copyright (c) 2008 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Matt Thomas <matt@3am-software.com>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``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 FOUNDATION OR CONTRIBUTORS
* 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.
*/
#include "atomic_op_asm.h"
#ifdef _ARM_ARCH_6
ENTRY_NP(_atomic_dec_32)
mov r2, r0 /* need r0 for return value */
1: ldrex r0, [r2] /* load old value (return value) */
sub r1, r0, #1 /* calculate new value */
strex r3, r1, [r2] /* try to store */
cmp r3, #0 /* succeed? */
bne 1b /* no, try again? */
RET /* return new value */
END(_atomic_dec_32)
ATOMIC_OP_ALIAS(atomic_dec_32,_atomic_dec_32)
ATOMIC_OP_ALIAS(atomic_dec_uint,_atomic_dec_32)
ATOMIC_OP_ALIAS(atomic_dec_ulong,_atomic_dec_32)
ATOMIC_OP_ALIAS(atomic_dec_ptr,_atomic_dec_32)
STRONG_ALIAS(_atomic_dec_uint,_atomic_dec_32)
STRONG_ALIAS(_atomic_dec_ulong,_atomic_dec_32)
STRONG_ALIAS(_atomic_dec_ptr,_atomic_dec_32)
ENTRY_NP(_atomic_dec_32_nv)
mov r2, r0 /* need r0 for return value */
1: ldrex r0, [r2] /* load old value */
sub r0, r0, #1 /* calculate new value (return value) */
strex r1, r0, [r2] /* try to store */
cmp r1, #0 /* succeed? */
bne 1b /* no, try again? */
RET /* return new value */
END(_atomic_dec_32_nv)
ATOMIC_OP_ALIAS(atomic_dec_32_nv,_atomic_dec_32_nv)
ATOMIC_OP_ALIAS(atomic_dec_uint_nv,_atomic_dec_32_nv)
ATOMIC_OP_ALIAS(atomic_dec_ulong_nv,_atomic_dec_32_nv)
ATOMIC_OP_ALIAS(atomic_dec_ptr_nv,_atomic_dec_32_nv)
STRONG_ALIAS(_atomic_dec_uint_nv,_atomic_dec_32_nv)
STRONG_ALIAS(_atomic_dec_ulong_nv,_atomic_dec_32_nv)
STRONG_ALIAS(_atomic_dec_ptr_nv,_atomic_dec_32_nv)
#endif /* _ARM_ARCH_6 */