LXR linux/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
  10void *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}
 103EXPORT_SYMBOL(memmove);
 104