xref: /minix3/lib/libc/arch/vax/string/index.S (revision e415d488727a332a2c69df018aa35e2cecf4148a)
1/*	$NetBSD: index.S,v 1.4 2011/01/25 02:38:15 matt Exp $	*/
2/*
3 * Copyright (c) 1980, 1993
4 *	The Regents of the University of California.  All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 * 3. Neither the name of the University nor the names of its contributors
15 *    may be used to endorse or promote products derived from this software
16 *    without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 */
30
31/*
32 * Find the first occurence of c in the string cp.
33 * Return pointer to match or null pointer.
34 *
35 * char *
36 * index(cp, c)
37 *	char *cp, c;
38 */
39#include "DEFS.h"
40
41#ifdef LIBC_SCCS
42RCSID("$NetSBD$")
43#endif
44
45/* Alas not quite twice as fast as the generic C version on a uvax2 */
46
47ENTRY(index, 0)
48	movq	4(%ap),%r0	# %r0 = cp; %r1 = c
49	tstb	%r1		# special case, looking for '\0'
50	jeql	3f
511:
52	cmpb	(%r0),%r1
53	jeql	2f
54	tstb	(%r0)+
55	jneq	1b
56	clrl	%r0		# return NULL if no match
572:
58	ret
593:
60	tstb	(%r0)+
61	jneq	3b
62	decl	%r0
63	jbr	2b
64END(index)
65