arch/m68k/lib/memmove.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file COPYING in the main directory of this archive
   4  * for more details.
   5  */
   6
   7 #include <linux/module.h>
   8 #include <linux/string.h>
   9
  10 void *memmove(void *dest, const void *src, size_t n)
  11 {
  12         void *xdest = dest;
  13         size_t temp;
  14
  15         if (!n)
  16                 return xdest;
  17
  18         if (dest < src) {
  19                 if ((long)dest & 1) {
  20                         char *cdest = dest;
  21                         const char *csrc = src;
  22                         *cdest++ = *csrc++;
  23                         dest = cdest;
  24                         src = csrc;
  25                         n--;
  26                 }
  27                 if (n > 2 && (long)dest & 2) {
  28                         short *sdest = dest;
  29                         const short *ssrc = src;
  30                         *sdest++ = *ssrc++;
  31                         dest = sdest;
  32                         src = ssrc;
  33                         n -= 2;
  34                 }
  35                 temp = n >> 2;
  36                 if (temp) {
  37                         long *ldest = dest;
  38                         const long *lsrc = src;
  39                         temp--;
  40                         do
  41                                 *ldest++ = *lsrc++;
  42                         while (temp--);
  43                         dest = ldest;
  44                         src = lsrc;
  45                 }
  46                 if (n & 2) {
  47                         short *sdest = dest;
  48                         const short *ssrc = src;
  49                         *sdest++ = *ssrc++;
  50                         dest = sdest;
  51                         src = ssrc;
  52                 }
  53                 if (n & 1) {
  54                         char *cdest = dest;
  55                         const char *csrc = src;
  56                         *cdest = *csrc;
  57                 }
  58         } else {
  59                 dest = (char *)dest + n;
  60                 src = (const char *)src + n;
  61                 if ((long)dest & 1) {
  62                         char *cdest = dest;
  63                         const char *csrc = src;
  64                         *--cdest = *--csrc;
  65                         dest = cdest;
  66                         src = csrc;
  67                         n--;
  68                 }
  69                 if (n > 2 && (long)dest & 2) {
  70                         short *sdest = dest;
  71                         const short *ssrc = src;
  72                         *--sdest = *--ssrc;
  73                         dest = sdest;
  74                         src = ssrc;
  75                         n -= 2;
  76                 }
  77                 temp = n >> 2;
  78                 if (temp) {
  79                         long *ldest = dest;
  80                         const long *lsrc = src;
  81                         temp--;
  82                         do
  83                                 *--ldest = *--lsrc;
  84                         while (temp--);
  85                         dest = ldest;
  86                         src = lsrc;
  87                 }
  88                 if (n & 2) {
  89                         short *sdest = dest;
  90                         const short *ssrc = src;
  91                         *--sdest = *--ssrc;
  92                         dest = sdest;
  93                         src = ssrc;
  94                 }
  95                 if (n & 1) {
  96                         char *cdest = dest;
  97                         const char *csrc = src;
  98                         *--cdest = *--csrc;
  99                 }
 100         }
 101         return xdest;
 102 }
 103 EXPORT_SYMBOL(memmove);