xref: /aosp_15_r20/bionic/libc/arch-riscv64/string/memcmp.c (revision 8d67ca893c1523eb926b9080dbe4e2ffd2a27ba1)
1*8d67ca89SAndroid Build Coastguard Worker /*-
2*8d67ca89SAndroid Build Coastguard Worker  * SPDX-License-Identifier: BSD-3-Clause
3*8d67ca89SAndroid Build Coastguard Worker  *
4*8d67ca89SAndroid Build Coastguard Worker  * Copyright (c) 1990, 1993
5*8d67ca89SAndroid Build Coastguard Worker  *	The Regents of the University of California.  All rights reserved.
6*8d67ca89SAndroid Build Coastguard Worker  *
7*8d67ca89SAndroid Build Coastguard Worker  * This code is derived from software contributed to Berkeley by
8*8d67ca89SAndroid Build Coastguard Worker  * Chris Torek.
9*8d67ca89SAndroid Build Coastguard Worker  *
10*8d67ca89SAndroid Build Coastguard Worker  * Redistribution and use in source and binary forms, with or without
11*8d67ca89SAndroid Build Coastguard Worker  * modification, are permitted provided that the following conditions
12*8d67ca89SAndroid Build Coastguard Worker  * are met:
13*8d67ca89SAndroid Build Coastguard Worker  * 1. Redistributions of source code must retain the above copyright
14*8d67ca89SAndroid Build Coastguard Worker  *    notice, this list of conditions and the following disclaimer.
15*8d67ca89SAndroid Build Coastguard Worker  * 2. Redistributions in binary form must reproduce the above copyright
16*8d67ca89SAndroid Build Coastguard Worker  *    notice, this list of conditions and the following disclaimer in the
17*8d67ca89SAndroid Build Coastguard Worker  *    documentation and/or other materials provided with the distribution.
18*8d67ca89SAndroid Build Coastguard Worker  * 3. Neither the name of the University nor the names of its contributors
19*8d67ca89SAndroid Build Coastguard Worker  *    may be used to endorse or promote products derived from this software
20*8d67ca89SAndroid Build Coastguard Worker  *    without specific prior written permission.
21*8d67ca89SAndroid Build Coastguard Worker  *
22*8d67ca89SAndroid Build Coastguard Worker  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23*8d67ca89SAndroid Build Coastguard Worker  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24*8d67ca89SAndroid Build Coastguard Worker  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25*8d67ca89SAndroid Build Coastguard Worker  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26*8d67ca89SAndroid Build Coastguard Worker  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27*8d67ca89SAndroid Build Coastguard Worker  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28*8d67ca89SAndroid Build Coastguard Worker  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29*8d67ca89SAndroid Build Coastguard Worker  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30*8d67ca89SAndroid Build Coastguard Worker  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31*8d67ca89SAndroid Build Coastguard Worker  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32*8d67ca89SAndroid Build Coastguard Worker  * SUCH DAMAGE.
33*8d67ca89SAndroid Build Coastguard Worker  */
34*8d67ca89SAndroid Build Coastguard Worker 
35*8d67ca89SAndroid Build Coastguard Worker #include <string.h>
36*8d67ca89SAndroid Build Coastguard Worker 
37*8d67ca89SAndroid Build Coastguard Worker /*
38*8d67ca89SAndroid Build Coastguard Worker  * Compare memory regions.
39*8d67ca89SAndroid Build Coastguard Worker  */
40*8d67ca89SAndroid Build Coastguard Worker int
memcmp_gc(const void * s1,const void * s2,size_t n)41*8d67ca89SAndroid Build Coastguard Worker memcmp_gc(const void *s1, const void *s2, size_t n)
42*8d67ca89SAndroid Build Coastguard Worker {
43*8d67ca89SAndroid Build Coastguard Worker 	if (n != 0) {
44*8d67ca89SAndroid Build Coastguard Worker 		const unsigned char *p1 = s1, *p2 = s2;
45*8d67ca89SAndroid Build Coastguard Worker 
46*8d67ca89SAndroid Build Coastguard Worker 		do {
47*8d67ca89SAndroid Build Coastguard Worker 			if (*p1++ != *p2++)
48*8d67ca89SAndroid Build Coastguard Worker 				return (*--p1 - *--p2);
49*8d67ca89SAndroid Build Coastguard Worker 		} while (--n != 0);
50*8d67ca89SAndroid Build Coastguard Worker 	}
51*8d67ca89SAndroid Build Coastguard Worker 	return (0);
52*8d67ca89SAndroid Build Coastguard Worker }
53