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
100
101
102
103
104
105
106
107
108
|
/* $OpenBSD: memmove.S,v 1.7 2014/11/29 18:51:23 tedu Exp $ */
/*-
* Copyright (c) 1993, 1994, 1995 Charles M. Hannum. All rights reserved.
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* William Jolitz.
*
* 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. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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/param.h>
#include <machine/asm.h>
/*
* Emulate bcopy() by swapping the first two arguments, and jumping
* into memmove(), which handles overlapping regions.
*/
ENTRY(bcopy)
pushl %esi
pushl %edi
movl 12(%esp),%esi
movl 16(%esp),%edi
jmp docopy
/*
* memmove(caddr_t dst, caddr_t src, size_t len);
* Copy len bytes, coping with overlapping space.
*/
ENTRY(memmove)
pushl %esi
pushl %edi
movl 12(%esp),%edi
movl 16(%esp),%esi
docopy:
movl 20(%esp),%ecx
movl %edi,%eax
subl %esi,%eax
cmpl %ecx,%eax # overlapping?
jb 1f
jmp docopyf # nope
/*
* memcpy() doesn't worry about overlap and always copies forward
*/
ENTRY(memcpy)
pushl %esi
pushl %edi
movl 12(%esp),%edi
movl 16(%esp),%esi
movl 20(%esp),%ecx
docopyf:
movl %edi,%eax # setup return value for memcpy/memmove
shrl $2,%ecx # copy by 32-bit words
rep
movsl
movl 20(%esp),%ecx
andl $3,%ecx # any bytes left?
rep
movsb
popl %edi
popl %esi
ret
_ALIGN_TEXT
1: movl %edi,%eax # setup return value for memmove
addl %ecx,%edi # copy backward
addl %ecx,%esi
std
andl $3,%ecx # any fractional bytes?
decl %edi
decl %esi
rep
movsb
movl 20(%esp),%ecx # copy remainder by 32-bit words
shrl $2,%ecx
subl $3,%esi
subl $3,%edi
rep
movsl
popl %edi
popl %esi
cld
ret
|
