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) 1994-2022 Free Software Foundation, Inc. 5 This file is part of the GNU C Library. 6 7 The GNU C Library is free software; you can redistribute it and/or 8 modify it under the terms of the GNU Lesser General Public 9 License as published by the Free Software Foundation; either 10 version 2.1 of the License, or (at your option) any later version. 11 12 The GNU C Library is distributed in the hope that it will be useful, 13 but WITHOUT ANY WARRANTY; without even the implied warranty of 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 Lesser General Public License for more details. 16 17 You should have received a copy of the GNU Lesser General Public 18 License along with the GNU C Library; if not, see 19 <https://www.gnu.org/licenses/>. */ 20 21#include <sysdep.h> 22#include "asm-syntax.h" 23 24#define PARMS 4 /* no space for saved regs */ 25#define RTN PARMS 26#define STR RTN 27#define STOP STR+4 28 29 .text 30ENTRY (strpbrk) 31 32 movl STR(%esp), %edx 33 movl STOP(%esp), %eax 34 35 /* First we create a table with flags for all possible characters. 36 For the ASCII (7bit/8bit) or ISO-8859-X character sets which are 37 supported by the C string functions we have 256 characters. 38 Before inserting marks for the stop characters we clear the whole 39 table. The unrolled form is much faster than a loop. */ 40 xorl %ecx, %ecx /* %ecx = 0 !!! */ 41 42 pushl %ecx /* make a 256 bytes long block filled with 0 */ 43 cfi_adjust_cfa_offset (4) 44 pushl %ecx 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 $0 /* These immediate values make the label 2 */ 159 cfi_adjust_cfa_offset (4) 160 pushl $0 /* to be aligned on a 16 byte boundary to */ 161 cfi_adjust_cfa_offset (4) 162 pushl $0 /* get a better performance of the loop. */ 163 cfi_adjust_cfa_offset (4) 164 pushl $0 165 cfi_adjust_cfa_offset (4) 166 pushl $0 167 cfi_adjust_cfa_offset (4) 168 pushl $0 169 cfi_adjust_cfa_offset (4) 170 171/* For understanding the following code remember that %ecx == 0 now. 172 Although all the following instruction only modify %cl we always 173 have a correct zero-extended 32-bit value in %ecx. */ 174 175/* Don't change the "testb $0xff,%%cl" to "testb %%cl,%%cl". We want 176 longer instructions so that the next loop aligns without adding nops. */ 177 178L(2): movb (%eax), %cl /* get byte from stopset */ 179 testb %cl, %cl /* is NUL char? */ 180 jz L(1) /* yes => start compare loop */ 181 movb %cl, (%esp,%ecx) /* set corresponding byte in stopset table */ 182 183 movb 1(%eax), %cl /* get byte from stopset */ 184 testb $0xff, %cl /* is NUL char? */ 185 jz L(1) /* yes => start compare loop */ 186 movb %cl, (%esp,%ecx) /* set corresponding byte in stopset table */ 187 188 movb 2(%eax), %cl /* get byte from stopset */ 189 testb $0xff, %cl /* is NUL char? */ 190 jz L(1) /* yes => start compare loop */ 191 movb %cl, (%esp,%ecx) /* set corresponding byte in stopset table */ 192 193 movb 3(%eax), %cl /* get byte from stopset */ 194 addl $4, %eax /* increment stopset pointer */ 195 movb %cl, (%esp,%ecx) /* set corresponding byte in stopset table */ 196 testb $0xff, %cl /* is NUL char? */ 197 jnz L(2) /* no => process next dword from stopset */ 198 199L(1): leal -4(%edx), %eax /* prepare loop */ 200 201 /* We use a neat trick for the following loop. Normally we would 202 have to test for two termination conditions 203 1. a character in the stopset was found 204 and 205 2. the end of the string was found 206 But as a sign that the character is in the stopset we store its 207 value in the table. But the value of NUL is NUL so the loop 208 terminates for NUL in every case. */ 209 210L(3): addl $4, %eax /* adjust pointer for full loop round */ 211 212 movb (%eax), %cl /* get byte from string */ 213 cmpb %cl, (%esp,%ecx) /* is it contained in stopset? */ 214 je L(4) /* yes => return */ 215 216 movb 1(%eax), %cl /* get byte from string */ 217 cmpb %cl, (%esp,%ecx) /* is it contained in stopset? */ 218 je L(5) /* yes => return */ 219 220 movb 2(%eax), %cl /* get byte from string */ 221 cmpb %cl, (%esp,%ecx) /* is it contained in stopset? */ 222 je L(6) /* yes => return */ 223 224 movb 3(%eax), %cl /* get byte from string */ 225 cmpb %cl, (%esp,%ecx) /* is it contained in stopset? */ 226 jne L(3) /* yes => return */ 227 228 incl %eax /* adjust pointer */ 229L(6): incl %eax 230L(5): incl %eax 231 232L(4): addl $256, %esp /* remove stopset */ 233 cfi_adjust_cfa_offset (-256) 234 235 orb %cl, %cl /* was last character NUL? */ 236 jnz L(7) /* no => return pointer */ 237 xorl %eax, %eax 238 239L(7): ret 240END (strpbrk) 241libc_hidden_builtin_def (strpbrk) 242