lh | 9ed821d | 2023-04-07 01:36:19 -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) 1994-2015 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 |
| 32 | ENTRY (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 | |
| 180 | L(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 | |
| 201 | L(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 | |
| 212 | L(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 */ |
| 231 | L(6): incl %eax |
| 232 | L(5): incl %eax |
| 233 | |
| 234 | L(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 | |
| 241 | L(7): ret |
| 242 | END (strpbrk) |
| 243 | libc_hidden_builtin_def (strpbrk) |