1 /* $NetBSD: memccpy.S,v 1.1 2001/02/05 00:17:22 scottr Exp $ */
4 * Copyright (C) 1999 Scott Reynolds. All rights reserved.
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
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. The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 #include <machine/asm.h>
31 #if defined(LIBC_SCCS) && !defined(lint)
32 RCSID("$NetBSD: memccpy.S,v 1.1 2001/02/05 00:17:22 scottr Exp $")
33 #endif /* LIBC_SCCS and not lint */
36 movl %sp@(16),%d0 | count
37 jeq Lmcbail | nothing to do
39 movl %sp@(4),%a0 | a0 = toaddr
40 subql #1,%d0 | prepare count for DBcc loop
41 movl %sp@(8),%a1 | a1 = fromaddr
42 movl %sp@(12),%d1 | d1 = terminator
43 jeq Lmcloop | handle ASCII NUL specially
45 movl %d2,%sp@- | save scratch register
47 movb %a1@+,%d2 | move a byte
49 cmpb %d2,%d1 | found the terminator?
50 dbeq %d0,Lmcnzloop | if not, keep transferring,
51 jeq Lmcnzdone | otherwise done
52 clrw %d0 | check to see if more to do
54 jcc Lmcnzloop | yes, keep going...
56 movl %sp@+,%d2 | restore scratch register
57 movql #0,%d0 | no terminator found, return NULL
59 movl %d0,%a0 | XXX maybe use lea to avoid stall?
64 movb %a1@+,%a0@+ | move a byte; was it NUL?
65 dbeq %d0,Lmcloop | if not, keep transferring,
66 jeq Lmcdone | otherwise done
67 clrw %d0 | check to see if more to do
69 jcc Lmcloop | yes, keep going...
70 | Note: %d0 is now -1!
71 movql #0,%d0 | no terminator found, return NULL
74 movl %d0,%a0 | XXX maybe use lea to avoid stall?
79 movl %sp@+,%d2 | restore scratch register