wcsmbs/wmemcmp.c

   1 /* Copyright (C) 1996, 1997, 2011 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 #ifndef WMEMCMP
  23 # define WMEMCMP wmemcmp
  24 #endif
  25
  26 int
  27 WMEMCMP (s1, s2, n)
  28      const wchar_t *s1;
  29      const wchar_t *s2;
  30      size_t n;
  31 {
  32   register wchar_t c1;
  33   register wchar_t c2;
  34
  35   while (n >= 4)
  36     {
  37       c1 = s1[0];
  38       c2 = s2[0];
  39       if (c1 - c2 != 0)
  40         return c1 > c2 ? 1 : -1;
  41       c1 = s1[1];
  42       c2 = s2[1];
  43       if (c1 - c2 != 0)
  44         return c1 > c2 ? 1 : -1;
  45       c1 = s1[2];
  46       c2 = s2[2];
  47       if (c1 - c2 != 0)
  48         return c1 > c2 ? 1 : -1;
  49       c1 = s1[3];
  50       c2 = s2[3];
  51       if (c1 - c2 != 0)
  52         return c1 > c2 ? 1 : -1;
  53       s1 += 4;
  54       s2 += 4;
  55       n -= 4;
  56     }
  57
  58   if (n > 0)
  59     {
  60       c1 = s1[0];
  61       c2 = s2[0];
  62       if (c1 - c2 != 0)
  63         return c1 > c2 ? 1 : -1;
  64       ++s1;
  65       ++s2;
  66       --n;
  67     }
  68   if (n > 0)
  69     {
  70       c1 = s1[0];
  71       c2 = s2[0];
  72       if (c1 - c2 != 0)
  73         return c1 > c2 ? 1 : -1;
  74       ++s1;
  75       ++s2;
  76       --n;
  77     }
  78   if (n > 0)
  79     {
  80       c1 = s1[0];
  81       c2 = s2[0];
  82       if (c1 - c2 != 0)
  83         return c1 > c2 ? 1 : -1;
  84     }
  85
  86   return 0;
  87 }