wcsmbs/wmemcmp.c

   1 /* Copyright (C) 1996, 1997 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1996.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #include <wchar.h>
  21
  22
  23 int
  24 wmemcmp (s1, s2, n)
  25      const wchar_t *s1;
  26      const wchar_t *s2;
  27      size_t n;
  28 {
  29   register wint_t c1;
  30   register wint_t c2;
  31
  32   while (n >= 4)
  33     {
  34       c1 = (wint_t) s1[0];
  35       c2 = (wint_t) s2[0];
  36       if (c1 - c2 != 0)
  37         return c1 - c2;
  38       c1 = (wint_t) s1[1];
  39       c2 = (wint_t) s2[1];
  40       if (c1 - c2 != 0)
  41         return c1 - c2;
  42       c1 = (wint_t) s1[2];
  43       c2 = (wint_t) s2[2];
  44       if (c1 - c2 != 0)
  45         return c1 - c2;
  46       c1 = (wint_t) s1[3];
  47       c2 = (wint_t) s2[3];
  48       if (c1 - c2 != 0)
  49         return c1 - c2;
  50       s1 += 4;
  51       s2 += 4;
  52       n -= 4;
  53     }
  54
  55   if (n > 0)
  56     {
  57       c1 = (wint_t) s1[0];
  58       c2 = (wint_t) s2[0];
  59       if (c1 - c2 != 0)
  60         return c1 - c2;
  61       ++s1;
  62       ++s2;
  63       --n;
  64     }
  65   if (n > 0)
  66     {
  67       c1 = (wint_t) s1[0];
  68       c2 = (wint_t) s2[0];
  69       if (c1 - c2 != 0)
  70         return c1 - c2;
  71       ++s1;
  72       ++s2;
  73       --n;
  74     }
  75   if (n > 0)
  76     {
  77       c1 = (wint_t) s1[0];
  78       c2 = (wint_t) s2[0];
  79       if (c1 - c2 != 0)
  80         return c1 - c2;
  81     }
  82
  83   return 0;
  84 }