xref: /minix/common/lib/libc/arch/mips/string/strcmp.S (revision ebfedea0)
1/*	$NetBSD: strcmp.S,v 1.2 2009/12/14 00:39:00 matt Exp $	*/
2
3/*-
4 * Copyright (c) 1991, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Ralph Campbell.
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 * 3. Neither the name of the University nor the names of its contributors
19 *    may be used to endorse or promote products derived from this software
20 *    without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35#include <mips/asm.h>
36
37#if defined(LIBC_SCCS) && !defined(lint)
38	/* RCSID("from: @(#)strcmp.s	8.1 (Berkeley) 6/4/93") */
39	RCSID("$NetBSD: strcmp.S,v 1.2 2009/12/14 00:39:00 matt Exp $")
40#endif /* LIBC_SCCS and not lint */
41
42/*
43 * NOTE: this version assumes unsigned chars in order to be "8 bit clean".
44 */
45LEAF(strcmp)
461:
47	lbu	t0, 0(a0)		# get two bytes and compare them
48	lbu	t1, 0(a1)
49	beq	t0, zero, LessOrEq	# end of first string?
50	bne	t0, t1, NotEq
51	lbu	t0, 1(a0)		# unroll loop
52	lbu	t1, 1(a1)
53	PTR_ADD	a0, a0, 2
54	beq	t0, zero, LessOrEq	# end of first string?
55	PTR_ADD	a1, a1, 2
56	beq	t0, t1, 1b
57NotEq:
58	subu	v0, t0, t1
59	j	ra
60LessOrEq:
61	subu	v0, zero, t1
62	j	ra
63END(strcmp)
64