xref: /netbsd-src/sys/lib/libkern/arch/m68k/skpc.S (revision 448e711c7835101c94f75b7ebddf58046df58290)
1/*
2 * Copyright (c) 1988 University of Utah.
3 * Copyright (c) 1980, 1990 The Regents of the University of California.
4 * All rights reserved.
5 *
6 * This code is derived from software contributed to Berkeley by
7 * the Systems Programming Group of the University of Utah Computer
8 * Science Department.
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. All advertising materials mentioning features or use of this software
19 *    must display the following acknowledgement:
20 *	This product includes software developed by the University of
21 *	California, Berkeley and its contributors.
22 * 4. Neither the name of the University nor the names of its contributors
23 *    may be used to endorse or promote products derived from this software
24 *    without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * SUCH DAMAGE.
37 *
38 *	from: Utah Hdr: locore.s 1.58 91/04/22
39 *	from: @(#)locore.s	7.11 (Berkeley) 5/9/91
40 *	$Id: skpc.S,v 1.1 1993/10/13 05:41:05 cgd Exp $
41 */
42
43#include "DEFS.h"
44
45/*
46 * Emulate fancy VAX string operations:
47 *	skpc(mask, count, startc)
48 */
49ENTRY(skpc)
50	movl	sp@(8),d0	| get length
51	jeq	Lskdone		| nothing to do, return
52	movb	sp@(7),d1	| mask to use
53	movl	sp@(12),a0	| where to start
54	subqw	#1,d0		| adjust for dbcc
55Lskloop:
56	cmpb	a0@+,d1		| compate with mask
57	dbne	d0,Lskloop	| keep going til no more or zero
58	addqw	#1,d0		| overshot by one
59Lskdone:
60	rts
61