Gitiles
Code Review Sign In
192.168.1.100 / T106_DC / 87b62aec91e139c60c796e1a28939395e27ee35c / . / ap / libc / glibc / glibc-2.23 / sysdeps / i386 / strpbrk.S
blob: ad2f02c3b847347f648de782d23d9b13ac19ee4f [file] [log] [blame]
xf.libdd93d52023-05-12 07:10:14 -0700[diff] [blame]1/* strcspn (str, ss) -- Return the length of the initial segement of STR
2 which contains no characters from SS.
3 For Intel 80x86, x>=3.
4 Copyright (C) 1994-2016 Free Software Foundation, Inc.
5 Contributed by Ulrich Drepper <drepper@gnu.ai.mit.edu>
6 Bug fixes by Alan Modra <Alan@SPRI.Levels.UniSA.Edu.Au>
7 This file is part of the GNU C Library.
8
9 The GNU C Library is free software; you can redistribute it and/or
10 modify it under the terms of the GNU Lesser General Public
11 License as published by the Free Software Foundation; either
12 version 2.1 of the License, or (at your option) any later version.
13
14 The GNU C Library is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 Lesser General Public License for more details.
18
19 You should have received a copy of the GNU Lesser General Public
20 License along with the GNU C Library; if not, see
21 <http://www.gnu.org/licenses/>. */
22
23#include <sysdep.h>
24#include "asm-syntax.h"
25
26#define PARMS 4 /* no space for saved regs */
27#define RTN PARMS
28#define STR RTN
29#define STOP STR+4
30
31 .text
32ENTRY (strpbrk)
33
34 movl STR(%esp), %edx
35 movl STOP(%esp), %eax
36
37 /* First we create a table with flags for all possible characters.
38 For the ASCII (7bit/8bit) or ISO-8859-X character sets which are
39 supported by the C string functions we have 256 characters.
40 Before inserting marks for the stop characters we clear the whole
41 table. The unrolled form is much faster than a loop. */
42 xorl %ecx, %ecx /* %ecx = 0 !!! */
43
44 pushl %ecx /* make a 256 bytes long block filled with 0 */
45 cfi_adjust_cfa_offset (4)
46 pushl %ecx
47 cfi_adjust_cfa_offset (4)
48 pushl %ecx
49 cfi_adjust_cfa_offset (4)
50 pushl %ecx
51 cfi_adjust_cfa_offset (4)
52 pushl %ecx
53 cfi_adjust_cfa_offset (4)
54 pushl %ecx
55 cfi_adjust_cfa_offset (4)
56 pushl %ecx
57 cfi_adjust_cfa_offset (4)
58 pushl %ecx
59 cfi_adjust_cfa_offset (4)
60 pushl %ecx
61 cfi_adjust_cfa_offset (4)
62 pushl %ecx
63 cfi_adjust_cfa_offset (4)
64 pushl %ecx
65 cfi_adjust_cfa_offset (4)
66 pushl %ecx
67 cfi_adjust_cfa_offset (4)
68 pushl %ecx
69 cfi_adjust_cfa_offset (4)
70 pushl %ecx
71 cfi_adjust_cfa_offset (4)
72 pushl %ecx
73 cfi_adjust_cfa_offset (4)
74 pushl %ecx
75 cfi_adjust_cfa_offset (4)
76 pushl %ecx
77 cfi_adjust_cfa_offset (4)
78 pushl %ecx
79 cfi_adjust_cfa_offset (4)
80 pushl %ecx
81 cfi_adjust_cfa_offset (4)
82 pushl %ecx
83 cfi_adjust_cfa_offset (4)
84 pushl %ecx
85 cfi_adjust_cfa_offset (4)
86 pushl %ecx
87 cfi_adjust_cfa_offset (4)
88 pushl %ecx
89 cfi_adjust_cfa_offset (4)
90 pushl %ecx
91 cfi_adjust_cfa_offset (4)
92 pushl %ecx
93 cfi_adjust_cfa_offset (4)
94 pushl %ecx
95 cfi_adjust_cfa_offset (4)
96 pushl %ecx
97 cfi_adjust_cfa_offset (4)
98 pushl %ecx
99 cfi_adjust_cfa_offset (4)
100 pushl %ecx
101 cfi_adjust_cfa_offset (4)
102 pushl %ecx
103 cfi_adjust_cfa_offset (4)
104 pushl %ecx
105 cfi_adjust_cfa_offset (4)
106 pushl %ecx
107 cfi_adjust_cfa_offset (4)
108 pushl %ecx
109 cfi_adjust_cfa_offset (4)
110 pushl %ecx
111 cfi_adjust_cfa_offset (4)
112 pushl %ecx
113 cfi_adjust_cfa_offset (4)
114 pushl %ecx
115 cfi_adjust_cfa_offset (4)
116 pushl %ecx
117 cfi_adjust_cfa_offset (4)
118 pushl %ecx
119 cfi_adjust_cfa_offset (4)
120 pushl %ecx
121 cfi_adjust_cfa_offset (4)
122 pushl %ecx
123 cfi_adjust_cfa_offset (4)
124 pushl %ecx
125 cfi_adjust_cfa_offset (4)
126 pushl %ecx
127 cfi_adjust_cfa_offset (4)
128 pushl %ecx
129 cfi_adjust_cfa_offset (4)
130 pushl %ecx
131 cfi_adjust_cfa_offset (4)
132 pushl %ecx
133 cfi_adjust_cfa_offset (4)
134 pushl %ecx
135 cfi_adjust_cfa_offset (4)
136 pushl %ecx
137 cfi_adjust_cfa_offset (4)
138 pushl %ecx
139 cfi_adjust_cfa_offset (4)
140 pushl %ecx
141 cfi_adjust_cfa_offset (4)
142 pushl %ecx
143 cfi_adjust_cfa_offset (4)
144 pushl %ecx
145 cfi_adjust_cfa_offset (4)
146 pushl %ecx
147 cfi_adjust_cfa_offset (4)
148 pushl %ecx
149 cfi_adjust_cfa_offset (4)
150 pushl %ecx
151 cfi_adjust_cfa_offset (4)
152 pushl %ecx
153 cfi_adjust_cfa_offset (4)
154 pushl %ecx
155 cfi_adjust_cfa_offset (4)
156 pushl %ecx
157 cfi_adjust_cfa_offset (4)
158 pushl %ecx
159 cfi_adjust_cfa_offset (4)
160 pushl $0 /* These immediate values make the label 2 */
161 cfi_adjust_cfa_offset (4)
162 pushl $0 /* to be aligned on a 16 byte boundary to */
163 cfi_adjust_cfa_offset (4)
164 pushl $0 /* get a better performance of the loop. */
165 cfi_adjust_cfa_offset (4)
166 pushl $0
167 cfi_adjust_cfa_offset (4)
168 pushl $0
169 cfi_adjust_cfa_offset (4)
170 pushl $0
171 cfi_adjust_cfa_offset (4)
172
173/* For understanding the following code remember that %ecx == 0 now.
174 Although all the following instruction only modify %cl we always
175 have a correct zero-extended 32-bit value in %ecx. */
176
177/* Don't change the "testb $0xff,%%cl" to "testb %%cl,%%cl". We want
178 longer instructions so that the next loop aligns without adding nops. */
179
180L(2): movb (%eax), %cl /* get byte from stopset */
181 testb %cl, %cl /* is NUL char? */
182 jz L(1) /* yes => start compare loop */
183 movb %cl, (%esp,%ecx) /* set corresponding byte in stopset table */
184
185 movb 1(%eax), %cl /* get byte from stopset */
186 testb $0xff, %cl /* is NUL char? */
187 jz L(1) /* yes => start compare loop */
188 movb %cl, (%esp,%ecx) /* set corresponding byte in stopset table */
189
190 movb 2(%eax), %cl /* get byte from stopset */
191 testb $0xff, %cl /* is NUL char? */
192 jz L(1) /* yes => start compare loop */
193 movb %cl, (%esp,%ecx) /* set corresponding byte in stopset table */
194
195 movb 3(%eax), %cl /* get byte from stopset */
196 addl $4, %eax /* increment stopset pointer */
197 movb %cl, (%esp,%ecx) /* set corresponding byte in stopset table */
198 testb $0xff, %cl /* is NUL char? */
199 jnz L(2) /* no => process next dword from stopset */
200
201L(1): leal -4(%edx), %eax /* prepare loop */
202
203 /* We use a neat trick for the following loop. Normally we would
204 have to test for two termination conditions
205 1. a character in the stopset was found
206 and
207 2. the end of the string was found
208 But as a sign that the character is in the stopset we store its
209 value in the table. But the value of NUL is NUL so the loop
210 terminates for NUL in every case. */
211
212L(3): addl $4, %eax /* adjust pointer for full loop round */
213
214 movb (%eax), %cl /* get byte from string */
215 cmpb %cl, (%esp,%ecx) /* is it contained in stopset? */
216 je L(4) /* yes => return */
217
218 movb 1(%eax), %cl /* get byte from string */
219 cmpb %cl, (%esp,%ecx) /* is it contained in stopset? */
220 je L(5) /* yes => return */
221
222 movb 2(%eax), %cl /* get byte from string */
223 cmpb %cl, (%esp,%ecx) /* is it contained in stopset? */
224 je L(6) /* yes => return */
225
226 movb 3(%eax), %cl /* get byte from string */
227 cmpb %cl, (%esp,%ecx) /* is it contained in stopset? */
228 jne L(3) /* yes => return */
229
230 incl %eax /* adjust pointer */
231L(6): incl %eax
232L(5): incl %eax
233
234L(4): addl $256, %esp /* remove stopset */
235 cfi_adjust_cfa_offset (-256)
236
237 orb %cl, %cl /* was last character NUL? */
238 jnz L(7) /* no => return pointer */
239 xorl %eax, %eax
240
241L(7): ret
242END (strpbrk)
243libc_hidden_builtin_def (strpbrk)