1/* Vector optimized 32/64 bit S/390 version of strncat. 2 Copyright (C) 2015-2022 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-strncat.h> 20#if HAVE_STRNCAT_Z13 21 22# include "sysdep.h" 23# include "asm-syntax.h" 24 25 .text 26 27/* char * strncat (const char *dest, const char *src, size_t n) 28 Concatenate two strings - at most n characters of src. 29 30 Register usage: 31 -r0=saved dest pointer for return 32 -r1=tmp 33 -r2=dest 34 -r3=src 35 -r4=n 36 -r5=current_len 37 -r6=tmp 38 -r7=tmp 39 -v16=part of src 40 -v17=index of zero 41 -v18=part of src 42 -v31=register save area for r6, r7 43*/ 44ENTRY(STRNCAT_Z13) 45 .machine "z13" 46 .machinemode "zarch_nohighgprs" 47 48# if !defined __s390x__ 49 llgfr %r4,%r4 50# endif /* !defined __s390x__ */ 51 52 clgfi %r4,0 53 ber %r14 /* Nothing to do, if n == 0. */ 54 lgr %r0,%r2 /* Save destination pointer for return. */ 55 vlvgp %v31,%r6,%r7 /* Save registers. */ 56 57 /* STRLEN 58 %r1 = loaded bytes (tmp) 59 %r6 = zero byte index (tmp) 60 %r2 = dst 61 */ 62 vlbb %v16,0(%r2),6 /* Load s until next 4k-byte boundary. */ 63 lcbb %r1,0(%r2),6 /* Get bytes to 4k-byte boundary or 16. */ 64 65 vfenezb %v16,%v16,%v16 /* Find element not equal with zero search. */ 66 vlgvb %r5,%v16,7 /* Load zero index or 16 if not found. */ 67 clrjl %r5,%r1,.Llen_end /* Found zero within loaded bytes, end. */ 68 69 /* Align s to 16 byte. */ 70 risbgn %r1,%r2,60,128+63,0 /* %r3 = bits 60-63 of %r2 'and' 15. */ 71 lghi %r5,16 /* current_len = 16. */ 72 slr %r5,%r1 /* Compute bytes to 16bytes boundary. */ 73 74 /* Find zero in 16byte aligned loop. */ 75.Llen_loop: 76 vl %v16,0(%r5,%r2) /* Load s. */ 77 vfenezbs %v16,%v16,%v16 /* Find element not equal with zero search. */ 78 je .Llen_found /* Jump away if zero was found. */ 79 vl %v16,16(%r5,%r2) 80 vfenezbs %v16,%v16,%v16 81 je .Llen_found16 82 vl %v16,32(%r5,%r2) 83 vfenezbs %v16,%v16,%v16 84 je .Llen_found32 85 vl %v16,48(%r5,%r2) 86 vfenezbs %v16,%v16,%v16 87 je .Llen_found48 88 89 aghi %r5,64 90 j .Llen_loop /* No zero -> loop. */ 91 92.Llen_found48: 93 aghi %r5,16 94.Llen_found32: 95 aghi %r5,16 96.Llen_found16: 97 aghi %r5,16 98.Llen_found: 99 vlgvb %r1,%v16,7 /* Load byte index of zero. */ 100 algr %r5,%r1 101 102.Llen_end: 103 /* STRCPY 104 %r1 = zero byte index (tmp) 105 %r6 = loaded bytes (tmp) 106 %r3 = curr src pointer 107 %r2 = curr dst pointer 108 %r7 = border, tmp 109 */ 110 la %r2,0(%r5,%r2) /* strcpy at end of dst-string. */ 111 112 vlbb %v16,0(%r3),6 /* Load s until next 4k-byte boundary. */ 113 lcbb %r6,0(%r3),6 /* Get bytes to 4k-byte boundary or 16. */ 114 llgfr %r6,%r6 /* Convert 32bit to 64bit. */ 115 116 lghi %r5,0 /* current_len = 0. */ 117 118 clgrjle %r4,%r6,.Lcpy_remaining_v16 /* If n <= loaded-bytes 119 -> process remaining. */ 120 121 /* n > loaded-byte-count. */ 122 vfenezb %v17,%v16,%v16 /* Find element not equal with zero search. */ 123 vlgvb %r1,%v17,7 /* Load zero index or 16 if not found. */ 124 clrjl %r1,%r6,.Lcpy_found_v16_store /* Found zero within loaded 125 bytes, copy and return. */ 126 127 /* Align s to 16 byte. */ 128 risbgn %r7,%r3,60,128+63,0 /* %r3 = bits 60-63 of %r2 'and' 15. */ 129 lghi %r5,15 /* current_len = 15. */ 130 slr %r5,%r7 /* Compute highest index to 16byte boundary. */ 131 132 /* Zero not found and n > loaded-byte-count. */ 133 vstl %v16,%r5,0(%r2) /* Copy loaded characters - no zero. */ 134 ahi %r5,1 /* Start loop at next character. */ 135 136 /* 137 Now we are 16byte aligned, so we can load a full vreg 138 without page fault. 139 */ 140 lgr %r1,%r5 /* If %r5 + 64 < maxlen? -> loop64. */ 141 aghi %r1,64 142 clgrjl %r1,%r4,.Lcpy_loop64 143 144 vl %v16,0(%r5,%r3) /* Load s. */ 145 clgijl %r4,17,.Lcpy_remaining_v16 /* If n <=16, 146 process remaining bytes. */ 147.Lcpy_lt64: 148 lgr %r7,%r4 149 slgfi %r7,16 /* border_len = n - 16. */ 150 151 /* If current_len >= border then process remaining bytes. */ 152 clgrjhe %r5,%r7,.Lcpy_remaining_v16 153 vfenezbs %v17,%v16,%v16 /* Find element not equal with zero search. */ 154 je .Lcpy_found_v16 /* Jump away if zero was found. */ 155 vl %v18,16(%r5,%r3) /* Load next part of s. */ 156 vst %v16,0(%r5,%r2) /* Store previous part without zero to dst. */ 157 aghi %r5,16 158 159 clgrjhe %r5,%r7,.Lcpy_remaining_v18 160 vfenezbs %v17,%v18,%v18 161 je .Lcpy_found_v18 162 vl %v16,16(%r5,%r3) 163 vst %v18,0(%r5,%r2) 164 aghi %r5,16 165 166 clgrjhe %r5,%r7,.Lcpy_remaining_v16 167 vfenezbs %v17,%v16,%v16 168 je .Lcpy_found_v16 169 vl %v18,16(%r5,%r3) 170 vst %v16,0(%r5,%r2) 171 aghi %r5,16 172 173.Lcpy_remaining_v18: 174 vlr %v16,%v18 175.Lcpy_remaining_v16: 176 /* v16 contains the remaining bytes [1...16]. 177 Store remaining bytes and append string-termination. */ 178 vfenezb %v17,%v16,%v16 /* Find element not equal with zero search. */ 179 slgrk %r7,%r4,%r5 /* Remaining bytes = maxlen - current_len. */ 180 aghi %r7,-1 /* vstl needs highest index. */ 181 vlgvb %r1,%v17,7 /* Load zero index or 16 if not found. */ 182 la %r2,0(%r5,%r2) /* vstl has no index register. */ 183 /* Zero-index within remaining-bytes, store up to zero and end. */ 184 clgrjle %r1,%r7,.Lcpy_found_v16_store 185 vstl %v16,%r7,0(%r2) /* Store remaining bytes. */ 186 lghi %r1,0 187 stc %r1,1(%r7,%r2) /* Store string-null-termination beyond n. */ 188.Lcpy_end: 189 /* Restore saved registers. */ 190 vlgvg %r6,%v31,0 191 vlgvg %r7,%v31,1 192 lgr %r2,%r0 /* Load saved dest-ptr. */ 193 br %r14 194 195.Lcpy_found_v16_32: 196 aghi %r5,32 197 j .Lcpy_found_v16 198.Lcpy_found_v18_48: 199 aghi %r5,32 200.Lcpy_found_v18_16: 201 aghi %r5,16 202.Lcpy_found_v18: 203 vlr %v16,%v18 204.Lcpy_found_v16: 205 /* v16 contains a zero. Store remaining bytes to zero. current_len 206 has not reached border, thus checking for n is not needed! */ 207 vlgvb %r1,%v17,7 /* Load byte index of zero. */ 208 la %r2,0(%r5,%r2) 209.Lcpy_found_v16_store: 210 vstl %v16,%r1,0(%r2) /* Copy characters including zero. */ 211 j .Lcpy_end 212 213 /* Find zero in 16byte aligned loop. */ 214.Lcpy_loop64: 215 vl %v16,0(%r5,%r3) /* Load s. */ 216 vfenezbs %v17,%v16,%v16 /* Find element not equal with zero search. */ 217 je .Lcpy_found_v16 /* Jump away if zero was found. */ 218 vl %v18,16(%r5,%r3) /* Load next part of s. */ 219 vst %v16,0(%r5,%r2) /* Store previous part without zero to dst. */ 220 vfenezbs %v17,%v18,%v18 221 je .Lcpy_found_v18_16 222 vl %v16,32(%r5,%r3) 223 vst %v18,16(%r5,%r2) 224 vfenezbs %v17,%v16,%v16 225 je .Lcpy_found_v16_32 226 vl %v18,48(%r5,%r3) 227 vst %v16,32(%r5,%r2) 228 vfenezbs %v17,%v18,%v18 229 je .Lcpy_found_v18_48 230 vst %v18,48(%r5,%r2) 231 232 aghi %r5,64 233 lgr %r1,%r5 /* If %r5 + 64 < maxlen? -> loop64. */ 234 aghi %r1,64 235 clgrjl %r1,%r4,.Lcpy_loop64 236 237 vl %v16,0(%r5,%r3) /* Load s. */ 238 j .Lcpy_lt64 239END(STRNCAT_Z13) 240 241# if ! HAVE_STRNCAT_IFUNC 242strong_alias (STRNCAT_Z13, strncat) 243# endif 244 245# if ! HAVE_STRNCAT_C 246/* See string/strncat.c and define STRNCAT_PRIMARY. */ 247strong_alias (STRNCAT_Z13, __strncat) 248# if defined SHARED && IS_IN (libc) 249strong_alias (__strncat, __GI___strncat) 250# endif 251# endif 252#endif 253