m68knommu: add optimize memmove() function

Add an m68k/coldfire optimized memmove() function for the m68knommu arch.
This is the same function as used by m68k. Simple speed tests show this
is faster once buffers are larger than 4 bytes, and significantly faster
on much larger buffers (4 times faster above about 100 bytes).

This also goes part of the way to fixing a regression caused by commit
ea61bc461d ("m68k/m68knommu: merge MMU and
non-MMU string.h"), which breaks non-coldfire non-mmu builds (which is
the 68x328 and 68360 families). They currently have no memmove() fucntion
defined, since there was none in the m68knommu/lib functions.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
This commit is contained in:
Greg Ungerer 2011-02-03 21:58:39 +10:00
parent f9d693d237
commit 982cd252ca
3 changed files with 107 additions and 2 deletions

View File

@ -99,10 +99,10 @@ static inline int strcmp(const char *cs, const char *ct)
: "+a" (cs), "+a" (ct), "=d" (res));
return res;
}
#endif /* CONFIG_COLDFIRE */
#define __HAVE_ARCH_MEMMOVE
extern void *memmove(void *, const void *, __kernel_size_t);
#endif /* CONFIG_COLDFIRE */
#define memcmp(d, s, n) __builtin_memcmp(d, s, n)

View File

@ -4,4 +4,4 @@
lib-y := ashldi3.o ashrdi3.o lshrdi3.o \
muldi3.o mulsi3.o divsi3.o udivsi3.o modsi3.o umodsi3.o \
checksum.o memcpy.o memset.o delay.o
checksum.o memcpy.o memmove.o memset.o delay.o

View File

@ -0,0 +1,105 @@
/*
* 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.
*/
#define __IN_STRING_C
#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);