kernel_optimize_test/arch/m68k/lib/memcpy.c
Linus Torvalds 1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00

76 lines
1.4 KiB
C

#include <linux/types.h>
void * memcpy(void * to, const void * from, size_t n)
{
void *xto = to;
size_t temp, temp1;
if (!n)
return xto;
if ((long) to & 1)
{
char *cto = to;
const char *cfrom = from;
*cto++ = *cfrom++;
to = cto;
from = cfrom;
n--;
}
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;
__asm__ __volatile__("movel %2,%3\n\t"
"andw #7,%3\n\t"
"lsrl #3,%2\n\t"
"negw %3\n\t"
"jmp %%pc@(1f,%3:w:2)\n\t"
"4:\t"
"movel %0@+,%1@+\n\t"
"movel %0@+,%1@+\n\t"
"movel %0@+,%1@+\n\t"
"movel %0@+,%1@+\n\t"
"movel %0@+,%1@+\n\t"
"movel %0@+,%1@+\n\t"
"movel %0@+,%1@+\n\t"
"movel %0@+,%1@+\n\t"
"1:\t"
"dbra %2,4b\n\t"
"clrw %2\n\t"
"subql #1,%2\n\t"
"jpl 4b\n\t"
: "=a" (lfrom), "=a" (lto), "=d" (temp),
"=&d" (temp1)
: "0" (lfrom), "1" (lto), "2" (temp)
);
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;
}