libs/port/memmove.c

   1 /*
   2  * memmove function
   3  *
   4  * Copyright 1996 Alexandre Julliard
   5  *
   6  * This 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  * This 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 this library; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  19  */
  20
  21 #include "config.h"
  22 #include "wine/port.h"
  23
  24 #ifndef HAVE_MEMMOVE
  25 void *memmove( void *dest, const void *source, size_t len )
  26 {
  27     register char *dst = dest;
  28     register const char *src = source;
  29
  30     /* Use memcpy if not overlapping */
  31     if ((dst + len <= src) || (src + len <= dst))
  32     {
  33         memcpy( dst, src, len );
  34     }
  35     /* Otherwise do it the hard way (FIXME: could do better than this) */
  36     else if (dst < src)
  37     {
  38         while (len--) *dst++ = *src++;
  39     }
  40     else
  41     {
  42         dst += len - 1;
  43         src += len - 1;
  44         while (len--) *dst-- = *src--;
  45     }
  46     return dest;
  47 }
  48 #endif  /* HAVE_MEMMOVE */