sysdeps/ia64/memccpy.S

   1 /* Optimized version of the memccpy() function.
   2    This file is part of the GNU C Library.
   3    Copyright (C) 2000-2014 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, see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 /* Return: a pointer to the next byte after char in dest or NULL
  21
  22    Inputs:
  23         in0:    dest
  24         in1:    src
  25         in2:    char
  26         in3:    byte count
  27
  28    This implementation assumes little endian mode (UM.be = 0).
  29
  30    This implementation assumes that it is safe to do read ahead
  31    in the src block, without getting beyond its limit.  */
  32
  33 #include <sysdep.h>
  34 #undef ret
  35
  36 #define OP_T_THRES      16
  37 #define OPSIZ           8
  38
  39 #define saved_pr        r17
  40 #define saved_lc        r18
  41 #define dest            r19
  42 #define src             r20
  43 #define len             r21
  44 #define asrc            r22
  45 #define tmp             r23
  46 #define char            r24
  47 #define charx8          r25
  48 #define saved_ec        r26
  49 #define sh2             r28
  50 #define sh1             r29
  51 #define loopcnt         r30
  52 #define value           r31
  53
  54 #ifdef GAS_ALIGN_BREAKS_UNWIND_INFO
  55 /* Manually force proper loop-alignment.  Note: be sure to
  56    double-check the code-layout after making any changes to
  57    this routine! */
  58 # define ALIGN(n)       { nop 0 }
  59 #else
  60 # define ALIGN(n)       .align n
  61 #endif
  62
  63 ENTRY(memccpy)
  64         .prologue
  65         alloc   r2 = ar.pfs, 4, 40 - 4, 0, 40
  66
  67 #include "softpipe.h"
  68         .rotr   r[MEMLAT + 7], tmp1[4], tmp2[4], val[4], tmp3[2], pos0[2]
  69         .rotp   p[MEMLAT + 6 + 1]
  70
  71         mov     ret0 = r0               // return NULL if no match
  72         .save pr, saved_pr
  73         mov     saved_pr = pr           // save the predicate registers
  74         mov     dest = in0              // dest
  75         .save ar.lc, saved_lc
  76         mov     saved_lc = ar.lc        // save the loop counter
  77         mov     saved_ec = ar.ec        // save the loop counter
  78         .body
  79         mov     src = in1               // src
  80         extr.u  char = in2, 0, 8        // char
  81         mov     len = in3               // len
  82         sub     tmp = r0, in0           // tmp = -dest
  83         cmp.ne  p7, p0 = r0, r0         // clear p7
  84         ;;
  85         and     loopcnt = 7, tmp        // loopcnt = -dest % 8
  86         cmp.ge  p6, p0 = OP_T_THRES, len        // is len <= OP_T_THRES
  87         mov     ar.ec = 0               // ec not guaranteed zero on entry
  88 (p6)    br.cond.spnt    .cpyfew         // copy byte by byte
  89         ;;
  90         cmp.eq  p6, p0 = loopcnt, r0
  91         mux1    charx8 = char, @brcst
  92 (p6)    br.cond.sptk .dest_aligned
  93         sub     len = len, loopcnt      // len -= -dest % 8
  94         adds    loopcnt = -1, loopcnt   // --loopcnt
  95         ;;
  96         mov     ar.lc = loopcnt
  97 .l1:                                    // copy -dest % 8 bytes
  98         ld1     value = [src], 1        // value = *src++
  99         ;;
 100         st1     [dest] = value, 1       // *dest++ = value
 101         cmp.eq  p6, p0 = value, char
 102 (p6)    br.cond.spnt .foundit
 103         br.cloop.dptk .l1
 104 .dest_aligned:
 105         and     sh1 = 7, src            // sh1 = src % 8
 106         and     tmp = -8, len           // tmp = len & -OPSIZ
 107         and     asrc = -8, src          // asrc = src & -OPSIZ  -- align src
 108         shr.u   loopcnt = len, 3        // loopcnt = len / 8
 109         and     len = 7, len ;;         // len = len % 8
 110         shl     sh1 = sh1, 3            // sh1 = 8 * (src % 8)
 111         adds    loopcnt = -1, loopcnt   // --loopcnt
 112         mov     pr.rot = 1 << 16 ;;     // set rotating predicates
 113         sub     sh2 = 64, sh1           // sh2 = 64 - sh1
 114         mov     ar.lc = loopcnt         // set LC
 115         cmp.eq  p6, p0 = sh1, r0        // is the src aligned?
 116 (p6)    br.cond.sptk .src_aligned ;;
 117         add     src = src, tmp          // src += len & -OPSIZ
 118         mov     ar.ec = MEMLAT + 6 + 1  // six more passes needed
 119         ld8     r[1] = [asrc], 8        // r[1] = w0
 120         cmp.ne  p6, p0 = r0, r0 ;;      // clear p6
 121         ALIGN(32)
 122 .l2:
 123 (p[0])          ld8.s   r[0] = [asrc], 8                // r[0] = w1
 124 (p[MEMLAT])     shr.u   tmp1[0] = r[1 + MEMLAT], sh1    // tmp1 = w0 >> sh1
 125 (p[MEMLAT])     shl     tmp2[0] = r[0 + MEMLAT], sh2    // tmp2 = w1 << sh2
 126 (p[MEMLAT+4])   xor     tmp3[0] = val[1], charx8
 127 (p[MEMLAT+5])   czx1.r  pos0[0] = tmp3[1]
 128 (p[MEMLAT+6])   chk.s   r[6 + MEMLAT], .recovery1       // our data isn't
 129                                                         // valid - rollback!
 130 (p[MEMLAT+6])   cmp.ne  p6, p0 = 8, pos0[1]
 131 (p6)            br.cond.spnt    .gotit
 132 (p[MEMLAT+6])   st8     [dest] = val[3], 8              // store val to dest
 133 (p[MEMLAT+3])   or      val[0] = tmp1[3], tmp2[3]       // val = tmp1 | tmp2
 134                 br.ctop.sptk    .l2
 135                 br.cond.sptk .cpyfew
 136
 137 .src_aligned:
 138                 cmp.ne  p6, p0 = r0, r0                 // clear p6
 139                 mov     ar.ec = MEMLAT + 2 + 1 ;;       // set EC
 140 .l3:
 141 (p[0])          ld8.s   r[0] = [src], 8
 142 (p[MEMLAT])     xor     tmp3[0] = r[MEMLAT], charx8
 143 (p[MEMLAT+1])   czx1.r  pos0[0] = tmp3[1]
 144 (p[MEMLAT+2])   cmp.ne  p7, p0 = 8, pos0[1]
 145 (p[MEMLAT+2])   chk.s   r[MEMLAT+2], .recovery2
 146 (p7)            br.cond.spnt    .gotit
 147 .back2:
 148 (p[MEMLAT+2])   st8     [dest] = r[MEMLAT+2], 8
 149                 br.ctop.dptk .l3
 150 .cpyfew:
 151         cmp.eq  p6, p0 = len, r0        // is len == 0 ?
 152         adds    len = -1, len           // --len;
 153 (p6)    br.cond.spnt    .restore_and_exit ;;
 154         mov     ar.lc = len
 155 .l4:
 156         ld1     value = [src], 1
 157         ;;
 158         st1     [dest] = value, 1
 159         cmp.eq  p6, p0 = value, char
 160 (p6)    br.cond.spnt .foundit
 161         br.cloop.dptk   .l4 ;;
 162 .foundit:
 163 (p6)    mov     ret0 = dest
 164 .restore_and_exit:
 165         mov     pr = saved_pr, -1       // restore the predicate registers
 166         mov     ar.lc = saved_lc        // restore the loop counter
 167         mov     ar.ec = saved_ec ;;     // restore the epilog counter
 168         br.ret.sptk.many b0
 169 .gotit:
 170         .pred.rel "mutex" p6, p7
 171 (p6)    mov     value = val[3]          // if coming from l2
 172 (p7)    mov     value = r[MEMLAT+2]     // if coming from l3
 173         mov     ar.lc = pos0[1] ;;
 174 .l5:
 175         extr.u  tmp = value, 0, 8 ;;
 176         st1     [dest] = tmp, 1
 177         shr.u   value = value, 8
 178         br.cloop.sptk .l5 ;;
 179         mov     ret0 = dest
 180         mov     pr = saved_pr, -1
 181         mov     ar.lc = saved_lc
 182         br.ret.sptk.many b0
 183
 184 .recovery1:
 185 #if MEMLAT != 6
 186 # error "MEMLAT must be 6!"
 187 #endif
 188         adds    src = -8, asrc
 189         mov     loopcnt = ar.lc
 190         mov     tmp = ar.ec
 191         ;;
 192 (p[0])  adds    src = -8, src
 193         ;;
 194 (p[1])  adds    src = -8, src
 195         sub     sh1 = (MEMLAT + 6 + 1), tmp
 196         ;;
 197 (p[2])  adds    src = -8, src
 198         ;;
 199 (p[3])  adds    src = -8, src
 200         shl     loopcnt = loopcnt, 3
 201         ;;
 202 (p[4])  adds    src = -8, src
 203         ;;
 204 (p[5])  adds    src = -8, src
 205         shl     sh1 = sh1, 3
 206         ;;
 207 (p[6])  adds    src = -8, src
 208         ;;
 209 (p[7])  adds    src = -8, src
 210         shl     tmp = tmp, 3
 211         ;;
 212 (p[8])  adds    src = -8, src
 213         ;;
 214 (p[9])  adds    src = -8, src
 215         shr.u   sh2 = sh2, 3
 216         ;;
 217 (p[10]) adds    src = -8, src
 218         ;;
 219 (p[11]) adds    src = -8, src
 220         add     len = len, loopcnt
 221         ;;
 222         sub     src = src, sh2
 223         ;;
 224         add     len = tmp, len
 225         add     src = sh1, src
 226         br.cond.sptk .cpyfew
 227
 228 .recovery2:
 229 #if MEMLAT != 6
 230 # error "MEMLAT must be 6!"
 231 #endif
 232         add     tmp = -8, src
 233 (p7)    br.cond.spnt .gotit
 234         ;;
 235 (p[0])  add     tmp = -8, tmp ;;
 236 (p[1])  add     tmp = -8, tmp ;;
 237 (p[2])  add     tmp = -8, tmp ;;
 238 (p[3])  add     tmp = -8, tmp ;;
 239 (p[4])  add     tmp = -8, tmp ;;
 240 (p[5])  add     tmp = -8, tmp ;;
 241 (p[6])  add     tmp = -8, tmp ;;
 242 (p[7])  add     tmp = -8, tmp ;;
 243         ld8     r[MEMLAT+2] = [tmp] ;;
 244         xor     pos0[1] = r[MEMLAT+2], charx8 ;;
 245         czx1.r  pos0[1] = pos0[1] ;;
 246         cmp.ne  p7, p6 = 8, pos0[1]
 247 (p7)    br.cond.spnt .gotit
 248         br.cond.sptk .back2
 249 END(memccpy)