freeldr/freeldr/rtl/memmove.c

   1 /*
   2  *  FreeLoader
   3  *  Copyright (C) 1998-2003  Brian Palmer  <brianp@sginet.com>
   4  *
   5  *  This program is free software; you can redistribute it and/or modify
   6  *  it under the terms of the GNU General Public License as published by
   7  *  the Free Software Foundation; either version 2 of the License, or
   8  *  (at your option) any later version.
   9  *
  10  *  This program 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
  13  *  GNU General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License
  16  *  along with this program; if not, write to the Free Software
  17  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  18  */
  19
  20 #include <freeldr.h>
  21
  22 void *memmove(void *dest, const void *src, size_t count)
  23 {
  24         char *char_dest = (char *)dest;
  25         char *char_src = (char *)src;
  26
  27         if ((char_dest <= char_src) || (char_dest >= (char_src+count)))
  28         {
  29                 /*  non-overlapping buffers */
  30                 while(count > 0)
  31                 {
  32                         *char_dest = *char_src;
  33                         char_dest++;
  34                         char_src++;
  35                         count--;
  36                 }
  37         }
  38         else
  39         {
  40                 /* overlaping buffers */
  41                 char_dest = (char *)dest + count - 1;
  42                 char_src = (char *)src + count - 1;
  43
  44                 while(count > 0)
  45                 {
  46                         *char_dest = *char_src;
  47                         char_dest--;
  48                         char_src--;
  49                         count--;
  50                 }
  51         }
  52
  53         return dest;
  54 }