memmove.c
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/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file COPYING in the main directory of this archive
* for more details.
*/
#include <linux/module.h>
#include <linux/string.h>
void *memmove(void *dest, const void *src, size_t n)
{
void *xdest = dest;
size_t temp;
if (!n)
return xdest;
if (dest < src) {
if ((long)dest & 1) {
char *cdest = dest;
const char *csrc = src;
*cdest++ = *csrc++;
dest = cdest;
src = csrc;
n--;
}
if (n > 2 && (long)dest & 2) {
short *sdest = dest;
const short *ssrc = src;
*sdest++ = *ssrc++;
dest = sdest;
src = ssrc;
n -= 2;
}
temp = n >> 2;
if (temp) {
long *ldest = dest;
const long *lsrc = src;
temp--;
do
*ldest++ = *lsrc++;
while (temp--);
dest = ldest;
src = lsrc;
}
if (n & 2) {
short *sdest = dest;
const short *ssrc = src;
*sdest++ = *ssrc++;
dest = sdest;
src = ssrc;
}
if (n & 1) {
char *cdest = dest;
const char *csrc = src;
*cdest = *csrc;
}
} else {
dest = (char *)dest + n;
src = (const char *)src + n;
if ((long)dest & 1) {
char *cdest = dest;
const char *csrc = src;
*--cdest = *--csrc;
dest = cdest;
src = csrc;
n--;
}
if (n > 2 && (long)dest & 2) {
short *sdest = dest;
const short *ssrc = src;
*--sdest = *--ssrc;
dest = sdest;
src = ssrc;
n -= 2;
}
temp = n >> 2;
if (temp) {
long *ldest = dest;
const long *lsrc = src;
temp--;
do
*--ldest = *--lsrc;
while (temp--);
dest = ldest;
src = lsrc;
}
if (n & 2) {
short *sdest = dest;
const short *ssrc = src;
*--sdest = *--ssrc;
dest = sdest;
src = ssrc;
}
if (n & 1) {
char *cdest = dest;
const char *csrc = src;
*--cdest = *--csrc;
}
}
return xdest;
}
EXPORT_SYMBOL(memmove);