1/* Optimized version of the standard strncpy() function. 2 This file is part of the GNU C Library. 3 Copyright (C) 2000, 2001, 2002, 2003 Free Software Foundation, Inc. 4 Contributed by Dan Pop <Dan.Pop@cern.ch> 5 and Jakub Jelinek <jakub@redhat.com>. 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 <http://www.gnu.org/licenses/>. */ 20 21/* Return: dest 22 23 Inputs: 24 in0: dest 25 in1: src 26 in2: len 27 28 In this form, it assumes little endian mode. 29 */ 30 31#include <sysdep.h> 32#undef ret 33 34#define saved_lc r15 35#define saved_pr r16 36#define thresh r17 37#define dest r18 38#define dest2 r19 39#define src r20 40#define len r21 41#define asrc r22 42#define tmp r23 43#define pos r24 44#define w0 r25 45#define w1 r26 46#define c r27 47#define sh2 r28 48#define sh1 r29 49#define loopcnt r30 50#define value r31 51 52ENTRY(strncpy) 53 .prologue 54 alloc r2 = ar.pfs, 3, 0, 29, 32 55 56#define MEMLAT 2 57 .rotr r[MEMLAT + 2] 58 .rotp p[MEMLAT + 1] 59 60 mov ret0 = in0 /* return value = dest */ 61 .save pr, saved_pr 62 mov saved_pr = pr /* save the predicate registers */ 63 .save ar.lc, saved_lc 64 mov saved_lc = ar.lc /* save the loop counter */ 65 mov ar.ec = 0 /* ec is not guaranteed to */ 66 /* be zero upon function entry */ 67 .body 68 cmp.geu p6, p5 = 24, in2 69(p6) br.cond.spnt .short_len 70 sub tmp = r0, in0 ;; /* tmp = -dest */ 71 mov len = in2 /* len */ 72 mov dest = in0 /* dest */ 73 mov src = in1 /* src */ 74 and tmp = 7, tmp ;; /* loopcnt = -dest % 8 */ 75 cmp.eq p6, p7 = tmp, r0 76 adds loopcnt = -1, tmp /* --loopcnt */ 77(p6) br.cond.sptk .dest_aligned ;; 78 sub len = len, tmp /* len -= -dest % 8 */ 79 mov ar.lc = loopcnt 80.l1: /* copy -dest % 8 bytes */ 81(p5) ld1 c = [src], 1 /* c = *src++ */ 82 ;; 83 st1 [dest] = c, 1 /* *dest++ = c */ 84 cmp.ne p5, p7 = c, r0 85 br.cloop.dptk .l1 ;; 86(p7) br.cond.dpnt .found0_align 87 88.dest_aligned: /* p7 should be cleared here */ 89 shr.u c = len, 3 /* c = len / 8 */ 90 and sh1 = 7, src /* sh1 = src % 8 */ 91 and asrc = -8, src ;; /* asrc = src & -OPSIZ -- align src */ 92 adds c = (MEMLAT-1), c /* c = (len / 8) + MEMLAT - 1 */ 93 sub thresh = 8, sh1 94 mov pr.rot = 1 << 16 /* set rotating predicates */ 95 shl sh1 = sh1, 3 ;; /* sh1 = 8 * (src % 8) */ 96 mov ar.lc = c /* "infinite" loop */ 97 sub sh2 = 64, sh1 /* sh2 = 64 - sh1 */ 98 cmp.eq p6, p0 = sh1, r0 /* is the src aligned? */ 99(p6) br.cond.sptk .src_aligned 100 adds c = -(MEMLAT-1), c ;; /* c = (len / 8) */ 101 ld8 r[1] = [asrc],8 102 mov ar.lc = c ;; 103 104 .align 32 105.l2: 106(p6) st8 [dest] = value, 8 /* store val to dest */ 107 ld8.s r[0] = [asrc], 8 108 shr.u value = r[1], sh1 ;; /* value = w0 >> sh1 */ 109 czx1.r pos = value ;; /* do we have an "early" zero */ 110 cmp.lt p7, p0 = pos, thresh /* in w0 >> sh1? */ 111 adds len = -8, len /* len -= 8 */ 112(p7) br.cond.dpnt .nonalign_found0 113 chk.s r[0], .recovery2 /* it is safe to do that only */ 114.back2: /* after the previous test */ 115 shl tmp = r[0], sh2 /* tmp = w1 << sh2 */ 116 ;; 117 or value = value, tmp ;; /* value |= tmp */ 118 czx1.r pos = value ;; 119 cmp.ne p7, p6 = 8, pos 120(p7) br.cond.dpnt .nonalign_found0 121 br.ctop.dptk .l2 ;; 122 adds len = 8, len 123 br.cond.sptk .not_found0 ;; 124.nonalign_found0: 125 cmp.gtu p6, p0 = -8, len 126(p6) br.cond.dptk .found0 127 adds len = 8, len 128 br.cond.sptk .not_found0 ;; 129 130 .align 32 131.src_aligned: 132.l3: 133(p[0]) ld8.s r[0] = [src], 8 134(p[MEMLAT]) chk.s r[MEMLAT], .recovery3 135.back3: 136(p[MEMLAT]) mov value = r[MEMLAT] 137(p[MEMLAT]) czx1.r pos = r[MEMLAT] ;; 138(p[MEMLAT]) cmp.ne p7, p0 = 8, pos 139(p[MEMLAT]) adds len = -8, len /* len -= 8 */ 140(p7) br.cond.dpnt .found0 141(p[MEMLAT]) st8 [dest] = r[MEMLAT], 8 142 br.ctop.dptk .l3 ;; 143 144 chk.s r[MEMLAT-1], .recovery4 145.back4: 146 mov value = r[MEMLAT-1] 147 148.not_found0: 149 cmp.eq p5, p6 = len, r0 150 adds len = -1, len 151(p5) br.cond.dptk .restore_and_exit ;; 152 mov ar.lc = len 153.l4: 154(p6) extr.u c = value, 0, 8 /* c = value & 0xff */ 155(p6) shr.u value = value, 8 ;; 156 st1 [dest] = c, 1 157 cmp.ne p6, p0 = c, r0 158 br.cloop.dptk .l4 159 br.cond.sptk .restore_and_exit 160 161.found0_align: 162 mov pos = 0 163 adds len = -8, len 164 mov value = 0 ;; 165.found0: 166 shl tmp = pos, 3 167 shr.u loopcnt = len, 4 /* loopcnt = len / 16 */ 168 mov c = -1 ;; 169 cmp.eq p6, p0 = loopcnt, r0 170 adds loopcnt = -1, loopcnt 171 shl c = c, tmp ;; 172 and len = 0xf, len 173 andcm value = value, c 174 mov ar.lc = loopcnt ;; 175 cmp.le p7, p0 = 8, len 176 adds dest2 = 16, dest 177 st8 [dest] = value, 8 178 and len = 0x7, len 179(p6) br.cond.dpnt .l6 ;; 180.l5: 181 st8 [dest] = r0, 16 182 st8 [dest2] = r0, 16 183 br.cloop.dptk .l5 ;; 184.l6: 185(p7) st8 [dest] = r0, 8 186 cmp.eq p5, p0 = len, r0 187 adds len = -1, len 188(p5) br.cond.dptk .restore_and_exit ;; 189 mov ar.lc = len ;; 190.l7: 191 st1 [dest] = r0, 1 192 br.cloop.dptk .l7 ;; 193.restore_and_exit: 194 mov ar.lc = saved_lc /* restore the loop counter */ 195 mov pr = saved_pr, -1 /* restore the predicate registers */ 196 br.ret.sptk.many b0 197 198.short_len: 199 cmp.eq p5, p0 = in2, r0 200 adds loopcnt = -1, in2 201(p5) br.cond.spnt .restore_and_exit ;; 202 mov ar.lc = loopcnt /* p6 should be set when we get here */ 203.l8: 204(p6) ld1 c = [in1], 1 /* c = *src++ */ 205 ;; 206 st1 [in0] = c, 1 /* *dest++ = c */ 207(p6) cmp.ne p6, p0 = c, r0 208 br.cloop.dptk .l8 209 ;; 210 mov ar.lc = saved_lc /* restore the loop counter */ 211 mov pr = saved_pr, -1 /* restore the predicate registers */ 212 br.ret.sptk.many b0 213.recovery2: 214 add c = 8, len 215 add tmp = -8, asrc ;; 216 cmp.gtu p8, p5 = c, thresh ;; 217(p8) ld8 r[0] = [tmp] 218(p5) mov r[0] = r0 219 br.cond.sptk .back2 220.recovery3: 221 add tmp = -(MEMLAT + 1) * 8, src ;; 222 ld8 r[MEMLAT] = [tmp] 223 br.cond.sptk .back3 224.recovery4: 225 cmp.eq p5, p6 = len, r0 226 add tmp = -MEMLAT * 8, src ;; 227(p6) ld8 r[MEMLAT - 1] = [tmp] 228(p5) mov r[MEMLAT - 1] = r0 229 br.cond.sptk .back4 230END(strncpy) 231libc_hidden_def (strncpy) 232