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
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
|
/* strcpy/stpcpy implementation 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"
#define PARMS LINKAGE+12 /* space for 3 saved regs */
#define RTN PARMS
#define DEST RTN+RTN_SIZE
#define SRC DEST+PTR_SIZE
#ifndef USE_AS_STPCPY
# define STRCPY strcpy
#endif
#define magic 0xfefefeff
.text
ENTRY (BP_SYM (STRCPY))
ENTER
pushl %edi
cfi_adjust_cfa_offset (4)
pushl %esi
cfi_adjust_cfa_offset (4)
pushl %ebx
cfi_adjust_cfa_offset (4)
movl DEST(%esp), %edi
cfi_rel_offset (edi, 8)
movl SRC(%esp), %esi
cfi_rel_offset (esi, 4)
CHECK_BOUNDS_LOW (%edi, DEST(%esp))
CHECK_BOUNDS_LOW (%esi, SRC(%esp))
xorl %eax, %eax
leal -1(%esi), %ecx
movl $magic, %ebx
cfi_rel_offset (ebx, 0)
andl $3, %ecx
#ifdef PIC
call 2f
cfi_adjust_cfa_offset (4)
2: popl %edx
cfi_adjust_cfa_offset (-4)
/* 0xb is the distance between 2: and 1: but we avoid writing
1f-2b because the assembler generates worse code. */
leal 0xb(%edx,%ecx,8), %ecx
#else
leal 1f(,%ecx,8), %ecx
#endif
jmp *%ecx
.align 8
1:
orb (%esi), %al
jz L(end)
stosb
xorl %eax, %eax
incl %esi
orb (%esi), %al
jz L(end)
stosb
xorl %eax, %eax
incl %esi
orb (%esi), %al
jz L(end)
stosb
xorl %eax, %eax
incl %esi
L(1): movl (%esi), %ecx
leal 4(%esi),%esi
subl %ecx, %eax
addl %ebx, %ecx
decl %eax
jnc L(3)
movl %ecx, %edx
xorl %ecx, %eax
subl %ebx, %edx
andl $~magic, %eax
jne L(4)
movl %edx, (%edi)
leal 4(%edi),%edi
jmp L(1)
L(3): movl %ecx, %edx
subl %ebx, %edx
L(4): movb %dl, (%edi)
testb %dl, %dl
movl %edx, %eax
jz L(end2)
shrl $16, %eax
movb %dh, 1(%edi)
#ifdef USE_AS_STPCPY
addl $1, %edi
#endif
cmpb $0, %dh
jz L(end2)
#ifdef USE_AS_STPCPY
movb %al, 1(%edi)
addl $1, %edi
cmpb $0, %al
jz L(end2)
addl $1, %edi
#else
movb %al, 2(%edi)
testb %al, %al
leal 3(%edi), %edi
jz L(end2)
#endif
L(end): movb %ah, (%edi)
L(end2):
/* GKM FIXME: check high bounds */
#ifdef USE_AS_STPCPY
movl %edi, %eax
#else
movl DEST(%esp), %eax
#endif
RETURN_BOUNDED_POINTER (DEST(%esp))
popl %ebx
cfi_adjust_cfa_offset (-4)
cfi_restore (ebx)
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 (STRCPY))
#ifndef USE_AS_STPCPY
libc_hidden_builtin_def (strcpy)
#endif
|
