1/* Compare two strings for differences. 2 For SPARC v7. 3 Copyright (C) 1996-2022 Free Software Foundation, Inc. 4 This file is part of the GNU C Library. 5 6 The GNU C Library is free software; you can redistribute it and/or 7 modify it under the terms of the GNU Lesser General Public 8 License as published by the Free Software Foundation; either 9 version 2.1 of the License, or (at your option) any later version. 10 11 The GNU C Library is distributed in the hope that it will be useful, 12 but WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 Lesser General Public License for more details. 15 16 You should have received a copy of the GNU Lesser General Public 17 License along with the GNU C Library; if not, see 18 <https://www.gnu.org/licenses/>. */ 19 20#include <sysdep.h> 21 22 /* Normally, this uses ((xword - 0x01010101) & 0x80808080) test 23 to find out if any byte in xword could be zero. This is fast, but 24 also gives false alarm for any byte in range 0x81-0xff. It does 25 not matter for correctness, as if this test tells us there could 26 be some zero byte, we check it byte by byte, but if bytes with 27 high bits set are common in the strings, then this will give poor 28 performance. You can #define EIGHTBIT_NOT_RARE and the algorithm 29 will use one tick slower, but more precise test 30 ((xword - 0x01010101) & (~xword) & 0x80808080), 31 which does not give any false alarms (but if some bits are set, 32 one cannot assume from it which bytes are zero and which are not). 33 It is yet to be measured, what is the correct default for glibc 34 in these days for an average user. 35 */ 36 37 .text 38 .align 4 39 40ENTRY(strcmp) 41 andcc %o0, 3, %g0 42 be 13f 43 sethi %hi(0x80808080), %g1 44 45 ldub [%o0], %o4 46 add %o0, 1, %o0 47 ldub [%o1], %o5 48 cmp %o4, 0 49 add %o1, 1, %o1 50 be 2f 51 subcc %o4, %o5, %o4 52 bne 2f 53 andcc %o0, 3, %g0 54 be 4f 55 or %g1, %lo(0x80808080), %o3 56 ldub [%o0], %o4 57 add %o0, 1, %o0 58 ldub [%o1], %o5 59 cmp %o4, 0 60 add %o1, 1, %o1 61 be 2f 62 subcc %o4, %o5, %o4 63 bne 2f 64 andcc %o0, 3, %g0 65 be 5f 66 sethi %hi(0x01010101), %g1 67 ldub [%o0], %o4 68 add %o0, 1, %o0 69 ldub [%o1], %o5 70 cmp %o4, 0 71 add %o1, 1, %o1 72 be 2f 73 subcc %o4, %o5, %o4 74 bne 2f 75 andcc %o1, 3, %g2 76 bne 12f 77 or %g1, %lo(0x01010101), %o2 78 b 1f 79 ld [%o0], %o4 802: retl 81 mov %o4, %o0 82 8313: or %g1, %lo(0x80808080), %o3 844: sethi %hi(0x01010101), %g1 855: andcc %o1, 3, %g2 86 bne 12f 87 or %g1, %lo(0x01010101), %o2 88 890: ld [%o0], %o4 901: ld [%o1], %o5 91 sub %o4, %o2, %g1 92 add %o0, 4, %o0 93 cmp %o4, %o5 94#ifdef EIGHTBIT_NOT_RARE 95 andn %g1, %o4, %g1 96#endif 97 bne 11f 98 andcc %g1, %o3, %g0 99 be 0b 100 add %o1, 4, %o1 101 102 srl %o4, 24, %g4 103 andcc %g4, 0xff, %g0 104 be 2f 105 srl %o4, 16, %g4 106 andcc %g4, 0xff, %g0 107 be 2f 108 srl %o4, 8, %g4 109 andcc %g4, 0xff, %g0 110 be 2f 111 andcc %o4, 0xff, %g0 112 bne,a 1b 113 ld [%o0], %o4 1142: retl 115 clr %o0 116 11711: srl %o4, 24, %g4 118 srl %o5, 24, %g5 119 andcc %g4, 0xff, %g0 120 be 3f 121 subcc %g4, %g5, %g4 122 bne 3f 123 srl %o5, 16, %g5 124 srl %o4, 16, %g4 125 andcc %g4, 0xff, %g0 126 be 3f 127 subcc %g4, %g5, %g4 128 bne 3f 129 srl %o5, 8, %g5 130 srl %o4, 8, %g4 131 andcc %g4, 0xff, %g0 132 be 3f 133 subcc %g4, %g5, %g4 134 bne 3f 135 subcc %o4, %o5, %o4 136 retl 137 mov %o4, %o0 1383: retl 139 mov %g4, %o0 140 14112: save %sp, -64, %sp 142 ld [%i0], %i4 143 sll %g2, 3, %g3 144 andn %i1, 3, %i1 145 mov 32, %l1 146 ld [%i1], %l2 147 mov -1, %g6 148 add %i1, 4, %i1 149 sub %l1, %g3, %l1 150 sll %g6, %g3, %g6 151 1521: sll %l2, %g3, %g5 153 and %i4, %g6, %l3 154 sub %i4, %i2, %g1 155#ifdef EIGHTBIT_NOT_RARE 156 andn %g1, %i4, %g1 157#endif 158 andcc %g1, %i3, %g1 159 bne 3f 160 cmp %g5, %l3 161 bne 2f 162 add %i0, 4, %i0 163 ld [%i1], %l2 164 add %i1, 4, %i1 165 srl %l2, %l1, %l4 166 or %l4, %g5, %l4 167 cmp %l4, %i4 168 be,a 1b 169 ld [%i0], %i4 170 restore %l4, %g0, %o3 171 retl 172 sub %o4, %o3, %o0 173 1742: sll %l2, %g3, %i2 175 srl %i4, %g3, %i3 176 srl %i2, %g3, %i2 177 restore 178 retl 179 sub %o3, %o2, %o0 180 1813: srl %i4, 24, %g4 182 srl %g5, 24, %l6 183 andcc %g4, 0xff, %g0 184 be 4f 185 subcc %g4, %l6, %g4 186 bne 4f 187 cmp %g2, 3 188 be 6f 189 srl %i4, 16, %g4 190 srl %g5, 16, %l6 191 andcc %g4, 0xff, %g0 192 be 4f 193 subcc %g4, %l6, %g4 194 bne 4f 195 cmp %g2, 2 196 be 5f 197 srl %i4, 8, %g4 198 srl %g5, 8, %l6 199 andcc %g4, 0xff, %g0 200 be 4f 201 subcc %g4, %l6, %g4 202 bne 4f 203 add %i0, 4, %i0 204 ld [%i1], %l2 205 add %i1, 4, %i1 206 srl %l2, 24, %g5 207 andcc %i4, 0xff, %g4 208 be 4f 209 subcc %g4, %g5, %g4 210 be,a 1b 211 ld [%i0], %i4 2124: jmpl %i7 + 8, %g0 213 restore %g4, %g0, %o0 214 2155: ld [%i1], %l2 216 add %i1, 4, %i1 217 add %i0, 4, %i0 218 srl %l2, 24, %l6 219 andcc %g4, 0xff, %g4 220 be 4b 221 subcc %g4, %l6, %g4 222 bne 4b 223 srl %l2, 16, %l6 224 andcc %i4, 0xff, %g4 225 and %l6, 0xff, %l6 226 be 4b 227 subcc %g4, %l6, %g4 228 be,a 1b 229 ld [%i0], %i4 230 jmpl %i7 + 8, %g0 231 restore %g4, %g0, %o0 232 2336: ld [%i1], %l2 234 add %i1, 4, %i1 235 add %i0, 4, %i0 236 srl %l2, 24, %l6 237 andcc %g4, 0xff, %g4 238 be 4b 239 subcc %g4, %l6, %g4 240 bne 4b 241 srl %l2, 16, %l6 242 srl %i4, 8, %g4 243 and %l6, 0xff, %l6 244 andcc %g4, 0xff, %g4 245 be 4b 246 subcc %g4, %l6, %g4 247 bne 4b 248 srl %l2, 8, %l6 249 andcc %i4, 0xff, %g4 250 and %l6, 0xff, %l6 251 be 4b 252 subcc %g4, %l6, %g4 253 be,a 1b 254 ld [%i0], %i4 255 jmpl %i7 + 8, %g0 256 restore %g4, %g0, %o0 257END(strcmp) 258libc_hidden_builtin_def (strcmp) 259