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
124
125
126
127
128
129
130
131
132
133
134
135
|
/* Highly optimized version for i586.
Copyright (C) 1997-2013 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
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
<http://www.gnu.org/licenses/>. */
#include <sysdep.h>
#include "asm-syntax.h"
#include "bp-sym.h"
#include "bp-asm.h"
/* BEWARE: `#ifdef memcpy' means that memcpy is redefined as `mempcpy',
and the return value is the byte after the last one copied in
the destination. */
#define MEMPCPY_P (defined memcpy)
#define PARMS LINKAGE+8 /* space for 2 saved regs */
#define RTN PARMS
#define DEST RTN+RTN_SIZE
#define SRC DEST+PTR_SIZE
#define LEN SRC+PTR_SIZE
.text
#if defined PIC && !defined NOT_IN_libc
ENTRY (__memcpy_chk)
movl 12(%esp), %eax
cmpl %eax, 16(%esp)
jb HIDDEN_JUMPTARGET (__chk_fail)
END (__memcpy_chk)
#endif
ENTRY (BP_SYM (memcpy))
ENTER
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
CHECK_BOUNDS_BOTH_WIDE (%edi, DEST(%esp), %ecx)
CHECK_BOUNDS_BOTH_WIDE (%esi, SRC(%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
#if !MEMPCPY_P
movl DEST(%esp), %eax
#endif
L(1): rep; movsb
#if MEMPCPY_P
movl %edi, %eax
#endif
popl %esi
cfi_adjust_cfa_offset (-4)
cfi_restore (esi)
popl %edi
cfi_adjust_cfa_offset (-4)
cfi_restore (edi)
LEAVE
RET_PTR
END (BP_SYM (memcpy))
#if !MEMPCPY_P
libc_hidden_builtin_def (memcpy)
#endif
|
