sysdeps/alpha/alphaev67/strcat.S

   1 /* Copyright (C) 2000-2015 Free Software Foundation, Inc.
   2    Contributed by Richard Henderson <rth@tamu.edu>, 1996.
   3    EV67 optimized by Rick Gorton <rick.gorton@alpha-processor.com>.
   4    This file is part of the GNU C Library.
   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 /* Append a null-terminated string from SRC to DST.  */
  21
  22 #include <sysdep.h>
  23
  24         .arch ev6
  25         .set noreorder
  26         .text
  27
  28 ENTRY(strcat)
  29         ldgp    gp, 0(pv)
  30 #ifdef PROF
  31         .set noat
  32         lda     AT, _mcount
  33         jsr     AT, (AT), _mcount
  34         .set at
  35 #endif
  36         .prologue 1
  37
  38         mov     $16, $0         # E : set up return value
  39         /* Find the end of the string.  */
  40         ldq_u   $1, 0($16)      # L : load first quadword (a0 may be misaligned)
  41         lda     $2, -1          # E :
  42         insqh   $2, $16, $2     # U :
  43
  44         andnot  $16, 7, $16     # E :
  45         or      $2, $1, $1      # E :
  46         cmpbge  $31, $1, $2     # E : bits set iff byte == 0
  47         bne     $2, $found      # U :
  48
  49 $loop:  ldq     $1, 8($16)      # L :
  50         addq    $16, 8, $16     # E :
  51         cmpbge  $31, $1, $2     # E :
  52         beq     $2, $loop       # U :
  53
  54 $found: cttz    $2, $3          # U0 :
  55         addq    $16, $3, $16    # E :
  56         /* Now do the append.  */
  57         mov     $26, $23        # E :
  58         jmp     $31, __stxcpy   # L0 :
  59
  60         END(strcat)
  61 libc_hidden_builtin_def (strcat)