Home | History | Annotate | Line # | Download | only in string 
      1 /*	$NetBSD: memcmp.c,v 1.8 2020/01/29 09:18:26 ad Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2020 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Andrew Doran.
      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 /*-
     33  * Copyright (c) 1990, 1993
     34  *	The Regents of the University of California.  All rights reserved.
     35  *
     36  * This code is derived from software contributed to Berkeley by
     37  * Chris Torek.
     38  *
     39  * Redistribution and use in source and binary forms, with or without
     40  * modification, are permitted provided that the following conditions
     41  * are met:
     42  * 1. Redistributions of source code must retain the above copyright
     43  *    notice, this list of conditions and the following disclaimer.
     44  * 2. Redistributions in binary form must reproduce the above copyright
     45  *    notice, this list of conditions and the following disclaimer in the
     46  *    documentation and/or other materials provided with the distribution.
     47  * 3. Neither the name of the University nor the names of its contributors
     48  *    may be used to endorse or promote products derived from this software
     49  *    without specific prior written permission.
     50  *
     51  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     52  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     53  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     54  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     55  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     56  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     57  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     58  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     59  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     60  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     61  * SUCH DAMAGE.
     62  */
     63 
     64 #include <sys/cdefs.h>
     65 #if defined(LIBC_SCCS) && !defined(lint)
     66 #if 0
     67 static char sccsid[] = "@(#)memcmp.c	8.1 (Berkeley) 6/4/93";
     68 #else
     69 __RCSID("$NetBSD: memcmp.c,v 1.8 2020/01/29 09:18:26 ad Exp $");
     70 #endif
     71 #endif /* LIBC_SCCS and not lint */
     72 
     73 #if !defined(_KERNEL) && !defined(_STANDALONE)
     74 #include <sys/types.h>
     75 
     76 #include <assert.h>
     77 #include <string.h>
     78 #else
     79 #include <lib/libkern/libkern.h>
     80 #endif
     81 
     82 #undef memcmp
     83 /*
     84  * Compare memory regions.
     85  */
     86 int
     87 memcmp(const void *s1, const void *s2, size_t n)
     88 {
     89 	const unsigned char *c1, *c2;
     90 
     91 #ifndef _STANDALONE
     92 	const uintptr_t *b1, *b2;
     93 
     94 	b1 = s1;
     95 	b2 = s2;
     96 
     97 #ifndef __NO_STRICT_ALIGNMENT
     98 	if ((((uintptr_t)b1 | (uintptr_t)b2) & (sizeof(uintptr_t) - 1)) == 0)
     99 #endif
    100 	{
    101 		while (n >= sizeof(uintptr_t)) {
    102 			if (*b1 != *b2)
    103 				break;
    104 			b1++;
    105 			b2++;
    106 			n -= sizeof(uintptr_t);
    107 		}
    108 	}
    109 
    110 	c1 = (const unsigned char *)b1;
    111 	c2 = (const unsigned char *)b2;
    112 #else
    113 	c1 = (const unsigned char *)s1;
    114 	c2 = (const unsigned char *)s2;
    115 #endif
    116 
    117 	if (n != 0) {
    118 		do {
    119 			if (*c1++ != *c2++)
    120 				return *--c1 - *--c2;
    121 		} while (--n != 0);
    122 	}
    123 
    124 	return 0;
    125 }
    126 
    127 #if defined(__ARM_EABI__)
    128 __strong_alias(__aeabi_memcmp, memcmp)
    129 #endif
    130