11.9Sskrll/*	$NetBSD: atomic_dec_64.S,v 1.9 2021/07/28 07:32:20 skrll Exp $	*/
21.1Smatt/*-
31.2Smatt * Copyright (c) 2012 The NetBSD Foundation, Inc.
41.1Smatt * All rights reserved.
51.1Smatt *
61.1Smatt * This code is derived from software contributed to The NetBSD Foundation
71.1Smatt * by Matt Thomas <matt@3am-software.com>
81.1Smatt *
91.1Smatt * Redistribution and use in source and binary forms, with or without
101.1Smatt * modification, are permitted provided that the following conditions
111.1Smatt * are met:
121.1Smatt * 1. Redistributions of source code must retain the above copyright
131.1Smatt *    notice, this list of conditions and the following disclaimer.
141.1Smatt * 2. Redistributions in binary form must reproduce the above copyright
151.1Smatt *    notice, this list of conditions and the following disclaimer in the
161.1Smatt *    documentation and/or other materials provided with the distribution.
171.1Smatt *
181.1Smatt * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
191.1Smatt * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
201.1Smatt * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
211.1Smatt * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
221.1Smatt * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
231.1Smatt * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
241.1Smatt * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
251.1Smatt * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
261.1Smatt * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
271.1Smatt * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
281.1Smatt * POSSIBILITY OF SUCH DAMAGE.
291.1Smatt */
301.1Smatt
311.1Smatt#include "atomic_op_asm.h"
321.1Smatt
331.8Sskrll#if defined(_ARM_ARCH_6)
341.1Smatt
351.5SmattENTRY_NP(_atomic_dec_64_nv)
361.5Smatt	mov	ip, r0			/* need r0 for return value */
371.7Sjoerg1:	ldrexd	r0, r1, [ip]		/* load old value */
381.3Smatt	subs	LO, LO, #1		/* calculate new value */
391.6Smatt	sbcs	HI, HI, #0		/* calculate new value */
401.7Sjoerg	strexd	r2, r0, r1, [ip]	/* try to store */
411.3Smatt	cmp	r2, #0			/*   succeed? */
421.1Smatt	bne	1b			/*     no, try again? */
431.1Smatt	RET				/* return new value */
441.5SmattEND(_atomic_dec_64_nv)
451.5Smatt
461.5SmattSTRONG_ALIAS(_atomic_dec_64,_atomic_dec_64_nv)
471.1SmattATOMIC_OP_ALIAS(atomic_dec_64_nv,_atomic_dec_64_nv)
481.5SmattATOMIC_OP_ALIAS(atomic_dec_64,_atomic_dec_64)
491.1Smatt
501.1Smatt#endif /* _ARM_ARCH_6 */
51