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 #define __IN_STRING_C
   8
   9 #include <linux/module.h>
  10 #include <linux/string.h>
  11
  12 void *memmove(void *dest, const void *src, size_t n)
  13 {
  14         void *xdest = dest;
  15         size_t temp;
  16
  17         if (!n)
  18                 return xdest;
  19
  20         if (dest < src) {
  21                 if ((long)dest & 1) {
  22                         char *cdest = dest;
  23                         const char *csrc = src;
  24                         *cdest++ = *csrc++;
  25                         dest = cdest;
  26                         src = csrc;
  27                         n--;
  28                 }
  29                 if (n > 2 && (long)dest & 2) {
  30                         short *sdest = dest;
  31                         const short *ssrc = src;
  32                         *sdest++ = *ssrc++;
  33                         dest = sdest;
  34                         src = ssrc;
  35                         n -= 2;
  36                 }
  37                 temp = n >> 2;
  38                 if (temp) {
  39                         long *ldest = dest;
  40                         const long *lsrc = src;
  41                         temp--;
  42                         do
  43                                 *ldest++ = *lsrc++;
  44                         while (temp--);
  45                         dest = ldest;
  46                         src = lsrc;
  47                 }
  48                 if (n & 2) {
  49                         short *sdest = dest;
  50                         const short *ssrc = src;
  51                         *sdest++ = *ssrc++;
  52                         dest = sdest;
  53                         src = ssrc;
  54                 }
  55                 if (n & 1) {
  56                         char *cdest = dest;
  57                         const char *csrc = src;
  58                         *cdest = *csrc;
  59                 }
  60         } else {
  61                 dest = (char *)dest + n;
  62                 src = (const char *)src + n;
  63                 if ((long)dest & 1) {
  64                         char *cdest = dest;
  65                         const char *csrc = src;
  66                         *--cdest = *--csrc;
  67                         dest = cdest;
  68                         src = csrc;
  69                         n--;
  70                 }
  71                 if (n > 2 && (long)dest & 2) {
  72                         short *sdest = dest;
  73                         const short *ssrc = src;
  74                         *--sdest = *--ssrc;
  75                         dest = sdest;
  76                         src = ssrc;
  77                         n -= 2;
  78                 }
  79                 temp = n >> 2;
  80                 if (temp) {
  81                         long *ldest = dest;
  82                         const long *lsrc = src;
  83                         temp--;
  84                         do
  85                                 *--ldest = *--lsrc;
  86                         while (temp--);
  87                         dest = ldest;
  88                         src = lsrc;
  89                 }
  90                 if (n & 2) {
  91                         short *sdest = dest;
  92                         const short *ssrc = src;
  93                         *--sdest = *--ssrc;
  94                         dest = sdest;
  95                         src = ssrc;
  96                 }
  97                 if (n & 1) {
  98                         char *cdest = dest;
  99                         const char *csrc = src;
 100                         *--cdest = *--csrc;
 101                 }
 102         }
 103         return xdest;
 104 }
 105 EXPORT_SYMBOL(memmove);