xref: /illumos-gate/usr/src/contrib/ast/src/lib/libast/comp/memcmp.c (revision ddb365bfc9e868ad24ccdcb0dc91af18b10df082)
1 /***********************************************************************
2 *                                                                      *
3 *               This software is part of the ast package               *
4 *          Copyright (c) 1985-2011 AT&T Intellectual Property          *
5 *                      and is licensed under the                       *
6 *                 Eclipse Public License, Version 1.0                  *
7 *                    by AT&T Intellectual Property                     *
8 *                                                                      *
9 *                A copy of the License is available at                 *
10 *          http://www.eclipse.org/org/documents/epl-v10.html           *
11 *         (with md5 checksum b35adb5213ca9657e911e9befb180842)         *
12 *                                                                      *
13 *              Information and Software Systems Research               *
14 *                            AT&T Research                             *
15 *                           Florham Park NJ                            *
16 *                                                                      *
17 *                 Glenn Fowler <gsf@research.att.com>                  *
18 *                  David Korn <dgk@research.att.com>                   *
19 *                   Phong Vo <kpv@research.att.com>                    *
20 *                                                                      *
21 ***********************************************************************/
22 #pragma prototyped
23 
24 #include <ast.h>
25 
26 #if _lib_memcmp
27 
28 NoN(memcmp)
29 
30 #else
31 
32 int
33 memcmp(const void* ab1, const void* ab2, size_t n)
34 {
35 	register const unsigned char*	b1 = (const unsigned char*)ab1;
36 	register const unsigned char*	b2 = (const unsigned char*)ab2;
37 	register const unsigned char*	e = b1 + n;
38 
39 	while (b1 < e)
40 		if (*b1++ != *b2++)
41 			return(*--b1 - *--b2);
42 	return(0);
43 }
44 
45 #endif
46