sysdeps/ia64/strcmp.S

   1 /* Optimized version of the standard strcmp() function.
   2    This file is part of the GNU C Library.
   3    Copyright (C) 2000-2016 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: the result of the comparison
  21
  22    Inputs:
  23         in0:    s1
  24         in1:    s2
  25
  26    Unlike memcmp(), this function is optimized for mismatches within the
  27    first few characters.  */
  28
  29 #include <sysdep.h>
  30 #undef ret
  31
  32 #define s1              in0
  33 #define s2              in1
  34
  35 #define val1            r15
  36 #define val2            r16
  37
  38
  39 ENTRY(strcmp)
  40         alloc   r2 = ar.pfs, 2, 0, 0, 0
  41 .loop:
  42         ld1     val1 = [s1], 1
  43         ld1     val2 = [s2], 1
  44         cmp.eq  p6, p0 = r0, r0         // set p6
  45         ;;
  46         cmp.ne.and p6, p0 = val1, r0
  47         cmp.ne.and p6, p0 = val2, r0
  48         cmp.eq.and p6, p0 = val1, val2
  49 (p6)    br.cond.sptk .loop
  50         sub     ret0 = val1, val2
  51         br.ret.sptk.many b0
  52 END(strcmp)
  53 libc_hidden_builtin_def (strcmp)