wcsmbs/wmemcmp.c

   1 /* Copyright (C) 1996-2013 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, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <wchar.h>
  20
  21 #ifndef WMEMCMP
  22 # define WMEMCMP wmemcmp
  23 #endif
  24
  25 int
  26 WMEMCMP (s1, s2, n)
  27      const wchar_t *s1;
  28      const wchar_t *s2;
  29      size_t n;
  30 {
  31   register wchar_t c1;
  32   register wchar_t c2;
  33
  34   while (n >= 4)
  35     {
  36       c1 = s1[0];
  37       c2 = s2[0];
  38       if (c1 - c2 != 0)
  39         return c1 > c2 ? 1 : -1;
  40       c1 = s1[1];
  41       c2 = s2[1];
  42       if (c1 - c2 != 0)
  43         return c1 > c2 ? 1 : -1;
  44       c1 = s1[2];
  45       c2 = s2[2];
  46       if (c1 - c2 != 0)
  47         return c1 > c2 ? 1 : -1;
  48       c1 = s1[3];
  49       c2 = s2[3];
  50       if (c1 - c2 != 0)
  51         return c1 > c2 ? 1 : -1;
  52       s1 += 4;
  53       s2 += 4;
  54       n -= 4;
  55     }
  56
  57   if (n > 0)
  58     {
  59       c1 = s1[0];
  60       c2 = s2[0];
  61       if (c1 - c2 != 0)
  62         return c1 > c2 ? 1 : -1;
  63       ++s1;
  64       ++s2;
  65       --n;
  66     }
  67   if (n > 0)
  68     {
  69       c1 = s1[0];
  70       c2 = s2[0];
  71       if (c1 - c2 != 0)
  72         return c1 > c2 ? 1 : -1;
  73       ++s1;
  74       ++s2;
  75       --n;
  76     }
  77   if (n > 0)
  78     {
  79       c1 = s1[0];
  80       c2 = s2[0];
  81       if (c1 - c2 != 0)
  82         return c1 > c2 ? 1 : -1;
  83     }
  84
  85   return 0;
  86 }