memcpy.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 *memcpy(void *to, const void *from, size_t n)
{
void *xto = to;
size_t temp;
if (!n)
return xto;
if ((long)to & 1) {
char *cto = to;
const char *cfrom = from;
*cto++ = *cfrom++;
to = cto;
from = cfrom;
n--;
}
#if defined(CONFIG_M68000)
if ((long)from & 1) {
char *cto = to;
const char *cfrom = from;
for (; n; n--)
*cto++ = *cfrom++;
return xto;
}
#endif
if (n > 2 && (long)to & 2) {
short *sto = to;
const short *sfrom = from;
*sto++ = *sfrom++;
to = sto;
from = sfrom;
n -= 2;
}
temp = n >> 2;
if (temp) {
long *lto = to;
const long *lfrom = from;
#if defined(CONFIG_M68000) || defined(CONFIG_COLDFIRE)
for (; temp; temp--)
*lto++ = *lfrom++;
#else
size_t temp1;
asm volatile (
" movel %2,%3\n"
" andw #7,%3\n"
" lsrl #3,%2\n"
" negw %3\n"
" jmp %%pc@(1f,%3:w:2)\n"
"4: movel %0@+,%1@+\n"
" movel %0@+,%1@+\n"
" movel %0@+,%1@+\n"
" movel %0@+,%1@+\n"
" movel %0@+,%1@+\n"
" movel %0@+,%1@+\n"
" movel %0@+,%1@+\n"
" movel %0@+,%1@+\n"
"1: dbra %2,4b\n"
" clrw %2\n"
" subql #1,%2\n"
" jpl 4b"
: "=a" (lfrom), "=a" (lto), "=d" (temp), "=&d" (temp1)
: "0" (lfrom), "1" (lto), "2" (temp));
#endif
to = lto;
from = lfrom;
}
if (n & 2) {
short *sto = to;
const short *sfrom = from;
*sto++ = *sfrom++;
to = sto;
from = sfrom;
}
if (n & 1) {
char *cto = to;
const char *cfrom = from;
*cto = *cfrom;
}
return xto;
}
EXPORT_SYMBOL(memcpy);