1/* Vector optimized 32/64 bit S/390 version of strcspn. 2 Copyright (C) 2015-2021 Free Software Foundation, Inc. 3 This file is part of the GNU C Library. 4 5 The GNU C Library is free software; you can redistribute it and/or 6 modify it under the terms of the GNU Lesser General Public 7 License as published by the Free Software Foundation; either 8 version 2.1 of the License, or (at your option) any later version. 9 10 The GNU C Library is distributed in the hope that it will be useful, 11 but WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13 Lesser General Public License for more details. 14 15 You should have received a copy of the GNU Lesser General Public 16 License along with the GNU C Library; if not, see 17 <https://www.gnu.org/licenses/>. */ 18 19#include <ifunc-strcspn.h> 20 21#if HAVE_STRCSPN_Z13 22 23# include "sysdep.h" 24# include "asm-syntax.h" 25 26 .text 27 28/* size_t strcspn (const char *s, const char * reject) 29 The strcspn() function calculates the length of the initial segment 30 of s which consists entirely of characters not in reject. 31 32 This method checks the length of reject string. If it fits entirely 33 in one vector register, a fast algorithm is used, which does not need 34 to check multiple parts of accept-string. Otherwise a slower full 35 check of accept-string is used. 36 37 register overview: 38 r3: pointer to start of reject-string 39 r2: pointer to start of search-string 40 r0: loaded byte count of vlbb search-string 41 r4: found byte index 42 r1: current return len 43 v16: search-string 44 v17: reject-string 45 v18: temp-vreg 46 47 ONLY FOR SLOW: 48 v19: first reject-string 49 v20: zero for preparing acc-vector 50 v21: global mask; 1 indicates a match between 51 search-string-vreg and any reject-character 52 v22: current mask; 1 indicates a match between 53 search-string-vreg and any reject-character in current acc-vreg 54 v24: one for result-checking of former string-part 55 v30, v31: for re-/storing registers r6, r8, r9 56 r5: current len of reject-string 57 r6: zero-index in search-string or 16 if no zero 58 or min(zero-index, loaded byte count) 59 r8: >0, if former reject-string-part contains a zero, 60 otherwise =0; 61 r9: loaded byte count of vlbb reject-string 62*/ 63ENTRY(STRCSPN_Z13) 64 .machine "z13" 65 .machinemode "zarch_nohighgprs" 66 67 /* 68 Check if reject-string fits in one vreg: 69 ---------------------------------------- 70 */ 71 vlbb %v17,0(%r3),6 /* Load reject. */ 72 lghi %r1,0 /* Zero out current len. */ 73 lcbb %r0,0(%r3),6 74 jo .Lcheck_onbb /* Special case if reject 75 lays on block-boundary. */ 76.Lcheck_notonbb: 77 vistrbs %v17,%v17 /* Fill with zeros after first zero. */ 78 je .Lfast /* Zero found -> reject fits in one vreg. */ 79 j .Lslow /* No zero -> reject exceeds one vreg. */ 80 81 82.Lcheck_onbb: 83 /* Reject lays on block-boundary. */ 84 vfenezb %v18,%v17,%v17 /* Search zero in loaded reject bytes. */ 85 vlgvb %r4,%v18,7 /* Get index of zero or 16 if not found. */ 86 clrjl %r4,%r0,.Lcheck_notonbb /* Zero index < loaded bytes count -> 87 Reject fits in one vreg; 88 Fill with zeros and proceed 89 with FAST. */ 90 vl %v17,0(%r3) /* Load reject, which exceeds loaded bytes. */ 91 j .Lcheck_notonbb /* Check if reject fits in one vreg. */ 92 93 94 /* 95 Search s for reject in one vreg 96 ------------------------------- 97 */ 98.Lfast: 99 /* Complete reject-string in v17 and remaining bytes are zero. */ 100 101 vlbb %v16,0(%r2),6 /* Load s until next 4k-byte boundary. */ 102 lcbb %r0,0(%r2),6 /* Get bytes to 4k-byte boundary or 16. */ 103 104 vfaezbs %v18,%v16,%v17,0 /* Find first element in v16 105 unequal to any in v17 106 or first zero element. */ 107 108 vlgvb %r4,%v18,7 /* Load byte index of found element. */ 109 clrjl %r4,%r0,.Lfast_loop_found2 /* If found index is within loaded 110 bytes, return with found element 111 index (=equal count). */ 112 113 /* Align s to 16 byte. */ 114 risbgn %r4,%r2,60,128+63,0 /* %r3 = bits 60-63 of %r2 'and' 15. */ 115 lghi %r1,16 /* current_len = 16. */ 116 slr %r1,%r4 /* Compute bytes to 16bytes boundary. */ 117 118 /* Process s in 16byte aligned loop. */ 119.Lfast_loop: 120 vl %v16,0(%r1,%r2) /* Load search-string. */ 121 vfaezbs %v18,%v16,%v17,0 /* Find first element in v16 equal to any 122 in v17 or first zero element. */ 123 jno .Lfast_loop_found 124 125 vl %v16,16(%r1,%r2) 126 vfaezbs %v18,%v16,%v17,0 127 jno .Lfast_loop_found16 128 129 vl %v16,32(%r1,%r2) 130 vfaezbs %v18,%v16,%v17,0 131 jno .Lfast_loop_found32 132 133 vl %v16,48(%r1,%r2) 134 vfaezbs %v18,%v16,%v17,0 135 jno .Lfast_loop_found48 136 137 aghi %r1,64 138 j .Lfast_loop /* Loop if no element was unequal to reject 139 and not zero. */ 140 141 /* Found equal or zero element. */ 142.Lfast_loop_found48: 143 aghi %r1,16 144.Lfast_loop_found32: 145 aghi %r1,16 146.Lfast_loop_found16: 147 aghi %r1,16 148.Lfast_loop_found: 149 vlgvb %r4,%v18,7 /* Load byte index of found element or zero. */ 150.Lfast_loop_found2: 151 algrk %r2,%r1,%r4 /* Add found index to current len. */ 152 br %r14 153 154 155 156 /* 157 Search s for reject in multiple vregs 158 ------------------------------------- 159 */ 160.Lslow: 161 /* Save registers. */ 162 vlvgg %v30,%r6,0 163 vlvgp %v31,%r8,%r9 164 165 /* Reject in v17 without zero. */ 166 vlr %v19,%v17 /* Save first acc-part for a fast reload. */ 167 vzero %v20 /* Zero for preparing acc-vector. */ 168 vone %v24 /* One for checking result of former 169 string-part. */ 170 171 /* Align s to 16 byte. */ 172 risbg %r4,%r2,60,128+63,0 /* Test if s is aligned and 173 %r4 = bits 60-63 'and' 15. */ 174 je .Lslow_loop_str /* If s is aligned, loop aligned. */ 175 lghi %r0,15 176 slr %r0,%r4 /* Compute highest index to load (15-x). */ 177 vll %v16,%r0,0(%r2) /* Load up to 16 byte boundary (vll needs 178 highest index, remaining bytes are 0). */ 179 ahi %r0,1 /* Work with loaded byte count. */ 180 vzero %v21 /* Zero out global mask. */ 181 lghi %r5,0 /* Set current len of reject-string to zero. */ 182 vfenezb %v18,%v16,%v16 /* Find zero in current string-part. */ 183 lghi %r8,0 /* There is no zero in first reject-part. */ 184 vlgvb %r6,%v18,7 /* Load byte index of zero or 16 if no zero. */ 185 clije %r6,0,.Lslow_end /* If first element is zero -> return 0. */ 186 clr %r0,%r6 /* cc==1 if loaded byte count < zero-index. */ 187 locrl %r6,%r0 /* Load on cc==1; zero-index = lbc. */ 188 j .Lslow_loop_acc 189 190 191 /* Process s in 16byte aligned loop. */ 192.Lslow_next_str: 193 /* Check results of former processed str-part. */ 194 vfeeb %v18,%v21,%v24 /* Find first equal match in global mask 195 (ones in element). */ 196 vlgvb %r4,%v18,7 /* Get index of first one (=equal) or 16. */ 197 /* Equal-index < min(zero-index, loaded byte count) 198 -> Return pointer to equal element. */ 199 clrjl %r4,%r6,.Lslow_index_found 200 /* Zero-index < loaded byte count 201 -> Former str-part was last str-part 202 -> Return null */ 203 clrjl %r6,%r0,.Lslow_end_not_found 204 205 /* All elements are zero (=no match) -> Proceed with next str-part. */ 206 vlr %v17,%v19 /* Load first part of reject (no zero). */ 207 algfr %r1,%r0 /* Add loaded byte count to current len. */ 208 209.Lslow_loop_str: 210 vl %v16,0(%r1,%r2) /* Load search-string. */ 211 lghi %r0,16 /* Loaded byte count is 16. */ 212 vzero %v21 /* Zero out global mask. */ 213 lghi %r5,0 /* Set current len of reject to zero. */ 214 vfenezb %v18,%v16,%v16 /* Find zero in current string-part. */ 215 lghi %r8,0 /* There is no zero in first reject-part. */ 216 vlgvb %r6,%v18,7 /* Load byte index of zero or 16 if no zero. */ 217 clije %r6,0,.Lslow_end /* If first element is zero (end of string) 218 -> Return current length. */ 219 220.Lslow_loop_acc: 221 vfaeb %v22,%v16,%v17,4 /* Create matching-mask (1 in mask -> 222 Character matches any rejected character in 223 this reject-string-part) IN=0, RT=1. */ 224 vlgvb %r4,%v22,0 /* Get result of first element. */ 225 /* First element is equal to any rejected characters? 226 (all other parts of reject cannot lead to a match before this one) 227 -> Return current len, which is pointing to this element. */ 228 clijh %r4,0,.Lslow_end 229 vo %v21,%v21,%v22 /* Global-mask = global-|matching-mask. */ 230 /* Proceed with next acc until end of acc is reached. */ 231 232 233.Lslow_next_acc: 234 clijh %r8,0,.Lslow_next_str /* There was a zero in last reject-part 235 -> Add found index to current len 236 and end. */ 237 vlbb %v17,16(%r5,%r3),6 /* Load next reject part. */ 238 aghi %r5,16 /* Increment current len of reject-string. */ 239 lcbb %r9,0(%r5,%r3),6 /* Get loaded byte count of reject-string. */ 240 jo .Lslow_next_acc_onbb /* Jump away if reject-string is 241 on block-boundary. */ 242.Lslow_next_acc_notonbb: 243 vistrbs %v17,%v17 /* Fill with zeros after first zero. */ 244 jo .Lslow_loop_acc /* No zero found -> no preparation needed. */ 245 246.Lslow_next_acc_prepare_zero: 247 /* Zero in reject-part: fill zeros with first-reject-character. */ 248 vlgvb %r8,%v17,0 /* Load first element of reject-part. */ 249 clije %r8,0,.Lslow_next_str /* Process next str-part if first 250 character in this part of reject 251 is a zero. */ 252 /* r8>0 -> zero found in this acc-part. */ 253 vrepb %v18,%v17,0 /* Replicate first char accross all chars. */ 254 vceqb %v22,%v20,%v17 /* Create a mask (v22) of null chars 255 by comparing with 0 (v20). */ 256 vsel %v17,%v18,%v17,%v22 /* Replace null chars with first char. */ 257 j .Lslow_loop_acc /* Reject-string part is prepared. */ 258 259.Lslow_next_acc_onbb: 260 vfenezb %v18,%v17,%v17 /* Find zero in loaded bytes of reject part. */ 261 vlgvb %r8,%v18,7 /* Load byte index of zero. */ 262 clrjl %r8,%r9,.Lslow_next_acc_notonbb /* Found a zero in loaded bytes 263 -> Prepare vreg. */ 264 vl %v17,0(%r5,%r3) /* Load over boundary ... */ 265 lghi %r8,0 /* r8=0 -> no zero in this part of acc, 266 check for zero is in jump-target. */ 267 j .Lslow_next_acc_notonbb /* ... and search for zero in 268 fully loaded vreg again. */ 269 270.Lslow_end_not_found: 271 algfr %r1,%r6 /* Add zero-index to current len. */ 272 j .Lslow_end 273.Lslow_index_found: 274 algfr %r1,%r4 /* Add found index of char to current len. */ 275.Lslow_end: 276 lgr %r2,%r1 277 /* Restore registers. */ 278 vlgvg %r6,%v30,0 279 vlgvg %r8,%v31,0 280 vlgvg %r9,%v31,1 281 br %r14 282END(STRCSPN_Z13) 283 284# if ! HAVE_STRCSPN_IFUNC 285strong_alias (STRCSPN_Z13, strcspn) 286# endif 287 288# if ! HAVE_STRCSPN_C && defined SHARED && IS_IN (libc) 289strong_alias (STRCSPN_Z13, __GI_strcspn) 290# endif 291 292#endif /* HAVE_STRCSPN_Z13 */ 293