1/*      $NetBSD: strncmp.S,v 1.2 2003/04/05 23:08:52 bjh21 Exp $ */
2
3/*
4 * Copyright (c) 2002 ARM Ltd
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. The name of the company may not be used to endorse or promote
16 *    products derived from this software without specific prior written
17 *    permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY ARM LTD ``AS IS'' AND ANY EXPRESS OR IMPLIED
20 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
21 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22 * IN NO EVENT SHALL ARM LTD BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
24 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
25 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
26 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
27 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
28 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31#include <machine/asm.h>
32
33__FBSDID("$FreeBSD$");
34
35ENTRY(strncmp)
36/* if (len == 0) return 0 */
37	cmp	r2, #0
38	moveq	r0, #0
39	moveq	pc, lr
40
41/* ip == last src address to compare */
42	adds	ip, r0, r2
43/* Use last possible address on overflow. */
44	movcs	ip, #0
45	sub	ip, ip, #1
461:
47	ldrb	r2, [r0], #1
48	ldrb	r3, [r1], #1
49	cmp	ip, r0
50	cmpcs	r2, #1
51	cmpcs	r2, r3
52	beq	1b
53	sub	r0, r2, r3
54	RET
55