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
memcmp(const void * s1,const void * s2,size_t n)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