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atomic_add_64_cas.c revision 1.7 
      1 /*	$NetBSD: atomic_add_64_cas.c,v 1.7 2014/01/27 18:29:47 matt Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2007 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 #ifdef __HAVE_ATOMIC64_OPS
     37 
     38 uint64_t __sync_fetch_and_add_8(volatile uint64_t *, int64_t);
     39 
     40 uint64_t
     41 __sync_fetch_and_add_8(volatile uint64_t *addr, int64_t val)
     42 {
     43 	uint64_t old, new;
     44 
     45 	do {
     46 		old = *addr;
     47 		new = old + val;
     48 	} while (atomic_cas_64(addr, old, new) != old);
     49 	return old;
     50 }
     51 
     52 void
     53 atomic_add_64(volatile uint64_t *addr, int64_t val)
     54 {
     55    (void) __sync_fetch_and_add_8(addr, val);
     56 }
     57 
     58 #undef atomic_add_64
     59 atomic_op_alias(atomic_add_64,_atomic_add_64)
     60 
     61 #if defined(_LP64)
     62 #undef atomic_add_long
     63 atomic_op_alias(atomic_add_long,_atomic_add_64)
     64 __strong_alias(_atomic_add_long,_atomic_add_64)
     65 
     66 #undef atomic_add_ptr
     67 atomic_op_alias(atomic_add_ptr,_atomic_add_64)
     68 __strong_alias(_atomic_add_ptr,_atomic_add_64)
     69 #endif /* _LP64 */
     70 
     71 #endif
     72