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memcmp.c revision 1.3.6.1 
      1 /*	$NetBSD: memcmp.c,v 1.3.6.1 2014/08/19 23:45:14 tls Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1990, 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * This code is derived from software contributed to Berkeley by
      8  * Chris Torek.
      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  * 3. Neither the name of the University nor the names of its contributors
     19  *    may be used to endorse or promote products derived from this software
     20  *    without specific prior written permission.
     21  *
     22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     32  * SUCH DAMAGE.
     33  */
     34 
     35 #include <sys/cdefs.h>
     36 #if defined(LIBC_SCCS) && !defined(lint)
     37 #if 0
     38 static char sccsid[] = "@(#)memcmp.c	8.1 (Berkeley) 6/4/93";
     39 #else
     40 __RCSID("$NetBSD: memcmp.c,v 1.3.6.1 2014/08/19 23:45:14 tls Exp $");
     41 #endif
     42 #endif /* LIBC_SCCS and not lint */
     43 
     44 #if !defined(_KERNEL) && !defined(_STANDALONE)
     45 #include <assert.h>
     46 #include <string.h>
     47 #else
     48 #include <lib/libkern/libkern.h>
     49 #endif
     50 
     51 #undef memcmp
     52 /*
     53  * Compare memory regions.
     54  */
     55 int
     56 memcmp(const void *s1, const void *s2, size_t n)
     57 {
     58 	_DIAGASSERT(s1 != 0);
     59 	_DIAGASSERT(s2 != 0);
     60 
     61 	if (n != 0) {
     62 		const unsigned char *p1 = s1, *p2 = s2;
     63 
     64 		do {
     65 			if (*p1++ != *p2++)
     66 				return (*--p1 - *--p2);
     67 		} while (--n != 0);
     68 	}
     69 	return (0);
     70 }
     71 
     72 #if defined(__ARM_EABI__)
     73 __strong_alias(__aeabi_memcmp, memcmp)
     74 #endif
     75