| lh | 9ed821d | 2023-04-07 01:36:19 -0700 | [diff] [blame^] | 1 | /* Optimized version of the standard strcpy() function. |
| 2 | This file is part of the GNU C Library. |
| 3 | Copyright (C) 2000, 2001, 2003 Free Software Foundation, Inc. |
| 4 | Contributed by Dan Pop <Dan.Pop@cern.ch>. |
| 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, write to the Free |
| 18 | Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
| 19 | 02111-1307 USA. */ |
| 20 | |
| 21 | /* Return: dest |
| 22 | |
| 23 | Inputs: |
| 24 | in0: dest |
| 25 | in1: src |
| 26 | |
| 27 | In this form, it assumes little endian mode. For big endian mode, the |
| 28 | the two shifts in .l2 must be inverted: |
| 29 | |
| 30 | shl value = r[1], sh1 // value = w0 << sh1 |
| 31 | shr.u tmp = r[0], sh2 // tmp = w1 >> sh2 |
| 32 | */ |
| 33 | |
| 34 | #include "sysdep.h" |
| 35 | #undef ret |
| 36 | |
| 37 | #define saved_lc r15 |
| 38 | #define saved_pr r16 |
| 39 | #define thresh r17 |
| 40 | #define dest r19 |
| 41 | #define src r20 |
| 42 | #define len r21 |
| 43 | #define asrc r22 |
| 44 | #define tmp r23 |
| 45 | #define pos r24 |
| 46 | #define w0 r25 |
| 47 | #define w1 r26 |
| 48 | #define c r27 |
| 49 | #define sh2 r28 |
| 50 | #define sh1 r29 |
| 51 | #define loopcnt r30 |
| 52 | #define value r31 |
| 53 | |
| 54 | ENTRY(strcpy) |
| 55 | .prologue |
| 56 | alloc r2 = ar.pfs, 2, 0, 30, 32 |
| 57 | |
| 58 | #define MEMLAT 2 |
| 59 | .rotr r[MEMLAT + 2] |
| 60 | .rotp p[MEMLAT + 1] |
| 61 | |
| 62 | mov ret0 = in0 /* return value = dest */ |
| 63 | .save pr, saved_pr |
| 64 | mov saved_pr = pr /* save the predicate registers */ |
| 65 | .save ar.lc, saved_lc |
| 66 | mov saved_lc = ar.lc /* save the loop counter */ |
| 67 | .body |
| 68 | sub tmp = r0, in0 ;; /* tmp = -dest */ |
| 69 | mov dest = in0 /* dest */ |
| 70 | mov src = in1 /* src */ |
| 71 | and loopcnt = 7, tmp ;; /* loopcnt = -dest % 8 */ |
| 72 | cmp.eq p6, p0 = loopcnt, r0 |
| 73 | adds loopcnt = -1, loopcnt /* --loopcnt */ |
| 74 | (p6) br.cond.sptk .dest_aligned ;; |
| 75 | mov ar.lc = loopcnt |
| 76 | .l1: /* copy -dest % 8 bytes */ |
| 77 | ld1 c = [src], 1 /* c = *src++ */ |
| 78 | ;; |
| 79 | st1 [dest] = c, 1 /* *dest++ = c */ |
| 80 | cmp.eq p6, p0 = c, r0 |
| 81 | (p6) br.cond.dpnt .restore_and_exit |
| 82 | br.cloop.dptk .l1 ;; |
| 83 | .dest_aligned: |
| 84 | and sh1 = 7, src /* sh1 = src % 8 */ |
| 85 | mov ar.lc = -1 /* "infinite" loop */ |
| 86 | and asrc = -8, src ;; /* asrc = src & -OPSIZ -- align src */ |
| 87 | sub thresh = 8, sh1 |
| 88 | mov pr.rot = 1 << 16 /* set rotating predicates */ |
| 89 | cmp.ne p7, p0 = r0, r0 /* clear p7 */ |
| 90 | shl sh1 = sh1, 3 ;; /* sh1 = 8 * (src % 8) */ |
| 91 | sub sh2 = 64, sh1 /* sh2 = 64 - sh1 */ |
| 92 | cmp.eq p6, p0 = sh1, r0 /* is the src aligned? */ |
| 93 | (p6) br.cond.sptk .src_aligned ;; |
| 94 | ld8 r[1] = [asrc],8 ;; |
| 95 | |
| 96 | .align 32 |
| 97 | .l2: |
| 98 | ld8.s r[0] = [asrc], 8 |
| 99 | shr.u value = r[1], sh1 ;; /* value = w0 >> sh1 */ |
| 100 | czx1.r pos = value ;; /* do we have an "early" zero */ |
| 101 | cmp.lt p7, p0 = pos, thresh /* in w0 >> sh1? */ |
| 102 | (p7) br.cond.dpnt .found0 |
| 103 | chk.s r[0], .recovery2 /* it is safe to do that only */ |
| 104 | .back2: /* after the previous test */ |
| 105 | shl tmp = r[0], sh2 /* tmp = w1 << sh2 */ |
| 106 | ;; |
| 107 | or value = value, tmp ;; /* value |= tmp */ |
| 108 | czx1.r pos = value ;; |
| 109 | cmp.ne p7, p0 = 8, pos |
| 110 | (p7) br.cond.dpnt .found0 |
| 111 | st8 [dest] = value, 8 /* store val to dest */ |
| 112 | br.ctop.dptk .l2 ;; |
| 113 | .src_aligned: |
| 114 | .l3: |
| 115 | (p[0]) ld8.s r[0] = [src], 8 |
| 116 | (p[MEMLAT]) chk.s r[MEMLAT], .recovery3 |
| 117 | .back3: |
| 118 | (p[MEMLAT]) mov value = r[MEMLAT] |
| 119 | (p[MEMLAT]) czx1.r pos = r[MEMLAT] ;; |
| 120 | (p[MEMLAT]) cmp.ne p7, p0 = 8, pos |
| 121 | (p7) br.cond.dpnt .found0 |
| 122 | (p[MEMLAT]) st8 [dest] = r[MEMLAT], 8 |
| 123 | br.ctop.dptk .l3 ;; |
| 124 | .found0: |
| 125 | mov ar.lc = pos |
| 126 | .l4: |
| 127 | extr.u c = value, 0, 8 /* c = value & 0xff */ |
| 128 | shr.u value = value, 8 |
| 129 | ;; |
| 130 | st1 [dest] = c, 1 |
| 131 | br.cloop.dptk .l4 ;; |
| 132 | .restore_and_exit: |
| 133 | mov ar.lc = saved_lc /* restore the loop counter */ |
| 134 | mov pr = saved_pr, -1 /* restore the predicate registers */ |
| 135 | br.ret.sptk.many b0 |
| 136 | .recovery2: |
| 137 | add tmp = -8, asrc ;; |
| 138 | ld8 r[0] = [tmp] |
| 139 | br.cond.sptk .back2 |
| 140 | .recovery3: |
| 141 | add tmp = -(MEMLAT + 1) * 8, src ;; |
| 142 | ld8 r[MEMLAT] = [tmp] |
| 143 | br.cond.sptk .back3 |
| 144 | END(strcpy) |
| 145 | libc_hidden_def (strcpy) |