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
|
/* Copy memory block and return pointer to beginning of destination block
For Intel 80x86, x>=6.
This file is part of the GNU C Library.
Copyright (C) 1999-2021 Free Software Foundation, Inc.
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1999.
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 /* no space for saved regs */
#define RTN PARMS
#define DEST RTN
#define SRC DEST+4
#define LEN SRC+4
.text
#if defined PIC && IS_IN (libc)
ENTRY_CHK (__memcpy_chk)
movl 12(%esp), %eax
cmpl %eax, 16(%esp)
jb HIDDEN_JUMPTARGET (__chk_fail)
END_CHK (__memcpy_chk)
#endif
ENTRY (memcpy)
movl %edi, %eax
movl DEST(%esp), %edi
movl %esi, %edx
movl SRC(%esp), %esi
movl %edi, %ecx
xorl %esi, %ecx
andl $3, %ecx
movl LEN(%esp), %ecx
cld
jne .Lunaligned
cmpl $3, %ecx
jbe .Lunaligned
testl $3, %esi
je 1f
movsb
decl %ecx
testl $3, %esi
je 1f
movsb
decl %ecx
testl $3, %esi
je 1f
movsb
decl %ecx
1: pushl %eax
movl %ecx, %eax
shrl $2, %ecx
andl $3, %eax
rep
movsl
movl %eax, %ecx
rep
movsb
popl %eax
.Lend: movl %eax, %edi
movl %edx, %esi
movl DEST(%esp), %eax
ret
/* When we come here the pointers do not have the same
alignment or the length is too short. No need to optimize for
aligned memory accesses. */
.Lunaligned:
shrl $1, %ecx
jnc 1f
movsb
1: shrl $1, %ecx
jnc 2f
movsw
2: rep
movsl
jmp .Lend
END (memcpy)
libc_hidden_builtin_def (memcpy)
|
