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
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
|
/* Highly optimized version for i586.
Copyright (C) 1997-2022 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <sysdep.h>
#include "asm-syntax.h"
#define PARMS 4+8 /* space for 2 saved regs */
#define RTN PARMS
#define DEST RTN
#define SRC DEST+4
#define LEN SRC+4
.text
#if defined PIC && IS_IN (libc)
ENTRY (__memcpy_chk)
movl 12(%esp), %eax
cmpl %eax, 16(%esp)
jb HIDDEN_JUMPTARGET (__chk_fail)
END (__memcpy_chk)
#endif
ENTRY (memcpy)
pushl %edi
cfi_adjust_cfa_offset (4)
pushl %esi
cfi_adjust_cfa_offset (4)
movl DEST(%esp), %edi
cfi_rel_offset (edi, 4)
movl SRC(%esp), %esi
cfi_rel_offset (esi, 0)
movl LEN(%esp), %ecx
movl %edi, %eax
/* We need this in any case. */
cld
/* Cutoff for the big loop is a size of 32 bytes since otherwise
the loop will never be entered. */
cmpl $32, %ecx
jbe L(1)
negl %eax
andl $3, %eax
subl %eax, %ecx
xchgl %eax, %ecx
rep; movsb
movl %eax, %ecx
subl $32, %ecx
js L(2)
/* Read ahead to make sure we write in the cache since the stupid
i586 designers haven't implemented read-on-write-miss. */
movl (%edi), %eax
L(3): movl 28(%edi), %edx
/* Now correct the loop counter. Please note that in the following
code the flags are not changed anymore. */
subl $32, %ecx
movl (%esi), %eax
movl 4(%esi), %edx
movl %eax, (%edi)
movl %edx, 4(%edi)
movl 8(%esi), %eax
movl 12(%esi), %edx
movl %eax, 8(%edi)
movl %edx, 12(%edi)
movl 16(%esi), %eax
movl 20(%esi), %edx
movl %eax, 16(%edi)
movl %edx, 20(%edi)
movl 24(%esi), %eax
movl 28(%esi), %edx
movl %eax, 24(%edi)
movl %edx, 28(%edi)
leal 32(%esi), %esi
leal 32(%edi), %edi
jns L(3)
/* Correct extra loop counter modification. */
L(2): addl $32, %ecx
#ifndef USE_AS_MEMPCPY
movl DEST(%esp), %eax
#endif
L(1): rep; movsb
#ifdef USE_AS_MEMPCPY
movl %edi, %eax
#endif
popl %esi
cfi_adjust_cfa_offset (-4)
cfi_restore (esi)
popl %edi
cfi_adjust_cfa_offset (-4)
cfi_restore (edi)
ret
END (memcpy)
#ifndef USE_AS_MEMPCPY
libc_hidden_builtin_def (memcpy)
#endif
|
