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      1 /*	$NetBSD: atomic_xor_8_cas.c,v 1.3 2014/06/23 21:53:45 joerg Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2014 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Jason R. Thorpe.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 #include "atomic_op_namespace.h"
     33 
     34 #include <sys/atomic.h>
     35 
     36 uint8_t fetch_and_xor_1(volatile uint8_t *, uint8_t, ...)
     37     asm("__sync_fetch_and_xor_1");
     38 uint8_t xor_and_fetch_1(volatile uint8_t *, uint8_t, ...)
     39     asm("__sync_xor_and_fetch_1");
     40 
     41 uint8_t
     42 fetch_and_xor_1(volatile uint8_t *addr, uint8_t val, ...)
     43 {
     44 	uint8_t old, new;
     45 
     46 	do {
     47 		old = *addr;
     48 		new = old ^ val;
     49 	} while (atomic_cas_8(addr, old, new) != old);
     50 	return old;
     51 }
     52 
     53 uint8_t
     54 xor_and_fetch_1(volatile uint8_t *addr, uint8_t val, ...)
     55 {
     56 	uint8_t old, new;
     57 
     58 	do {
     59 		old = *addr;
     60 		new = old ^ val;
     61 	} while (atomic_cas_8(addr, old, new) != old);
     62 	return new;
     63 }
     64 
     65 __strong_alias(__atomic_fetch_xor_1,__sync_fetch_and_xor_1)
     66