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
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
|
/* strtok (str, delim) -- Return next DELIM separated token from STR.
For Intel 80686.
Copyright (C) 1998, 2000 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include <sysdep.h>
#include "asm-syntax.h"
#include "bp-sym.h"
#include "bp-asm.h"
/* This file can be used for three variants of the strtok function:
strtok:
INPUT PARAMETER:
str (sp + 4)
delim (sp + 8)
strtok_r:
INPUT PARAMETER:
str (sp + 4)
delim (sp + 8)
save_ptr (sp + 12)
We do a common implementation here. */
#ifndef USE_AS_STRTOK_R
.bss
.local save_ptr
ASM_TYPE_DIRECTIVE (save_ptr, @object)
.size save_ptr, 4
save_ptr:
.space 4
#define FUNCTION BP_SYM (strtok)
#endif
.text
#if !defined USE_AS_STRTOK_R && defined PIC
0: movl (%esp), %ebx
ret
#endif
#define PARMS LINKAGE /* no space for saved regs */
#define RTN PARMS
#define STR RTN+RTN_SIZE
#define DELIM STR+PTR_SIZE
#define SAVE DELIM+PTR_SIZE
ENTRY (BP_SYM (FUNCTION))
ENTER
#if !defined USE_AS_STRTOK_R && defined PIC
pushl %ebx /* Save PIC register. */
call 0b
addl $_GLOBAL_OFFSET_TABLE_, %ebx
#endif
/* First we create a table with flags for all possible characters.
For the ASCII (7bit/8bit) or ISO-8859-X character sets which are
supported by the C string functions we have 256 characters.
Before inserting marks for the stop characters we clear the whole
table. */
movl %edi, %edx
subl $256, %esp
movl $64, %ecx
movl %esp, %edi
xorl %eax, %eax
cld
rep
stosl
/* Note: %ecx = 0 !!! */
movl %edx, %edi
#if !defined USE_AS_STRTOK_R && defined PIC
movl 264(%esp), %edx /* Get start of string. */
#else
movl 260(%esp), %edx /* Get start of string. */
#endif
#ifdef USE_AS_STRTOK_R
/* The value is stored in the third argument. */
movl 268(%esp), %eax
movl (%eax), %eax
#else
/* The value is in the local variable defined above. But
we have to take care for PIC code. */
# ifndef PIC
movl save_ptr, %eax
# else
movl save_ptr@GOTOFF(%ebx), %eax
# endif
#endif
/* If the pointer is NULL we have to use the stored value of
the last run. */
cmpl $0, %edx
cmove %eax, %edx
#if !defined USE_AS_STRTOK_R && defined PIC
movl 268(%esp), %eax /* Get start of delimiter set. */
#else
movl 264(%esp), %eax /* Get start of delimiter set. */
#endif
/* For understanding the following code remember that %ecx == 0 now.
Although all the following instruction only modify %cl we always
have a correct zero-extended 32-bit value in %ecx. */
L(2): movb (%eax), %cl /* get byte from stopset */
testb %cl, %cl /* is NUL char? */
jz L(1) /* yes => start compare loop */
movb %cl, (%esp,%ecx) /* set corresponding byte in stopset table */
movb 1(%eax), %cl /* get byte from stopset */
testb $0xff, %cl /* is NUL char? */
jz L(1) /* yes => start compare loop */
movb %cl, (%esp,%ecx) /* set corresponding byte in stopset table */
movb 2(%eax), %cl /* get byte from stopset */
testb $0xff, %cl /* is NUL char? */
jz L(1) /* yes => start compare loop */
movb %cl, (%esp,%ecx) /* set corresponding byte in stopset table */
movb 3(%eax), %cl /* get byte from stopset */
addl $4, %eax /* increment stopset pointer */
movb %cl, (%esp,%ecx) /* set corresponding byte in stopset table */
testb $0xff, %cl /* is NUL char? */
jnz L(2) /* no => process next dword from stopset */
L(1): leal -4(%edx), %eax /* prepare loop */
/* We use a neat trick for the following loop. Normally we would
have to test for two termination conditions
1. a character in the stopset was found
and
2. the end of the string was found
As a sign that the character is in the stopset we store its
value in the table. The value of NUL is NUL so the loop
terminates for NUL in every case. */
L(3): addl $4, %eax /* adjust pointer for full loop round */
movb (%eax), %cl /* get byte from string */
testb %cl, (%esp,%ecx) /* is it contained in stopset? */
jz L(4) /* no => start of token */
movb 1(%eax), %cl /* get byte from string */
testb %cl, (%esp,%ecx) /* is it contained in stopset? */
jz L(5) /* no => start of token */
movb 2(%eax), %cl /* get byte from string */
testb %cl, (%esp,%ecx) /* is it contained in stopset? */
jz L(6) /* no => start of token */
movb 3(%eax), %cl /* get byte from string */
testb %cl, (%esp,%ecx) /* is it contained in stopset? */
jnz L(3) /* yes => start of loop */
incl %eax /* adjust pointer */
L(6): incl %eax
L(5): incl %eax
/* Now we have to terminate the string. */
L(4): leal -4(%eax), %edx /* We use %EDX for the next run. */
L(7): addl $4, %edx /* adjust pointer for full loop round */
movb (%edx), %cl /* get byte from string */
cmpb %cl, (%esp,%ecx) /* is it contained in skipset? */
je L(8) /* yes => return */
movb 1(%edx), %cl /* get byte from string */
cmpb %cl, (%esp,%ecx) /* is it contained in skipset? */
je L(9) /* yes => return */
movb 2(%edx), %cl /* get byte from string */
cmpb %cl, (%esp,%ecx) /* is it contained in skipset? */
je L(10) /* yes => return */
movb 3(%edx), %cl /* get byte from string */
cmpb %cl, (%esp,%ecx) /* is it contained in skipset? */
jne L(7) /* no => start loop again */
incl %edx /* adjust pointer */
L(10): incl %edx
L(9): incl %edx
L(8): /* Remove the stopset table. */
addl $256, %esp
cmpl %eax, %edx
je L(returnNULL) /* There was no token anymore. */
movb $0, (%edx) /* Terminate string. */
/* Are we at end of string? */
cmpb $0, %cl
leal 1(%edx), %ecx
cmovne %ecx, %edx
L(return):
/* Store the pointer to the next character. */
#ifdef USE_AS_STRTOK_R
movl 12(%esp), %ecx
movl %edx, (%ecx)
#else
# ifndef PIC
movl %edx, save_ptr
# else
movl %edx, save_ptr@GOTOFF(%ebx)
popl %ebx
# endif
#endif
ret
L(returnNULL):
xorl %eax, %eax
jmp L(return)
END (BP_SYM (FUNCTION))
|
