1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
|
/* $NetBSD: memccpy.S,v 1.5 2014/03/18 18:20:37 riastradh Exp $ */
/*
* Copyright (C) 1999 Scott Reynolds. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <machine/asm.h>
#if defined(LIBC_SCCS) && !defined(lint)
RCSID("$NetBSD: memccpy.S,v 1.5 2014/03/18 18:20:37 riastradh Exp $")
#endif /* LIBC_SCCS and not lint */
ENTRY(memccpy)
movl 16(%sp),%d0 | count
jeq Lmcbail | nothing to do
movl 4(%sp),%a0 | a0 = toaddr
#ifndef __mcoldfire__
subql #1,%d0 | prepare count for DBcc loop
#endif
movl 8(%sp),%a1 | a1 = fromaddr
movl 12(%sp),%d1 | d1 = terminator
jeq Lmcloop | handle ASCII NUL specially
movl %d2,-(%sp) | save scratch register
Lmcnzloop:
movb (%a1)+,%d2 | move a byte
movb %d2,(%a0)+
cmpb %d2,%d1 | found the terminator?
#ifndef __mcoldfire__
dbeq %d0,Lmcnzloop | if not, keep transferring,
#endif
jeq Lmcnzdone | otherwise done
#ifdef __mcoldfire__
subql #1,%d0
jne Lmcnzloop
#else
clrw %d0 | check to see if more to do
subql #1,%d0
jcc Lmcnzloop | yes, keep going...
#endif
movl (%sp)+,%d2 | restore scratch register
movql #0,%d0 | no terminator found, return NULL
#ifdef __SVR4_ABI__
movl %d0,%a0 | XXX maybe use lea to avoid stall?
#endif
rts
Lmcloop:
movb (%a1)+,(%a0)+ | move a byte; was it NUL?
#ifndef __mcoldfire__
dbeq %d0,Lmcloop | if not, keep transferring,
#endif
jeq Lmcdone | otherwise done
#ifdef __mcoldfire__
subql #1,%d0
jne Lmcloop
#else
clrw %d0 | check to see if more to do
subql #1,%d0
jcc Lmcloop | yes, keep going...
#endif
| Note: %d0 is now -1!
movql #0,%d0 | no terminator found, return NULL
Lmcbail:
#ifdef __SVR4_ABI__
movl %d0,%a0 | XXX maybe use lea to avoid stall?
#endif
rts
Lmcnzdone:
movl (%sp)+,%d2 | restore scratch register
Lmcdone:
movl %a0,%d0
rts
END(memccpy)
|
