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// SPDX-License-Identifier: GPL-2.0
/*
* arch/openrisc/lib/memcpy.c
*
* Optimized memory copy routines for openrisc. These are mostly copied
* from ohter sources but slightly entended based on ideas discuassed in
* #openrisc.
*
* The word unroll implementation is an extension to the arm byte
* unrolled implementation, but using word copies (if things are
* properly aligned)
*
* The great arm loop unroll algorithm can be found at:
* arch/arm/boot/compressed/string.c
*/
#include <linux/export.h>
#include <linux/string.h>
#ifdef CONFIG_OR1K_1200
/*
* Do memcpy with word copies and loop unrolling. This gives the
* best performance on the OR1200 and MOR1KX archirectures
*/
void *memcpy(void *dest, __const void *src, __kernel_size_t n)
{
int i = 0;
unsigned char *d, *s;
uint32_t *dest_w = (uint32_t *)dest, *src_w = (uint32_t *)src;
/* If both source and dest are word aligned copy words */
if (!((unsigned int)dest_w & 3) && !((unsigned int)src_w & 3)) {
/* Copy 32 bytes per loop */
for (i = n >> 5; i > 0; i--) {
*dest_w++ = *src_w++;
*dest_w++ = *src_w++;
*dest_w++ = *src_w++;
*dest_w++ = *src_w++;
*dest_w++ = *src_w++;
*dest_w++ = *src_w++;
*dest_w++ = *src_w++;
*dest_w++ = *src_w++;
}
if (n & 1 << 4) {
*dest_w++ = *src_w++;
*dest_w++ = *src_w++;
*dest_w++ = *src_w++;
*dest_w++ = *src_w++;
}
if (n & 1 << 3) {
*dest_w++ = *src_w++;
*dest_w++ = *src_w++;
}
if (n & 1 << 2)
*dest_w++ = *src_w++;
d = (unsigned char *)dest_w;
s = (unsigned char *)src_w;
} else {
d = (unsigned char *)dest_w;
s = (unsigned char *)src_w;
for (i = n >> 3; i > 0; i--) {
*d++ = *s++;
*d++ = *s++;
*d++ = *s++;
*d++ = *s++;
*d++ = *s++;
*d++ = *s++;
*d++ = *s++;
*d++ = *s++;
}
if (n & 1 << 2) {
*d++ = *s++;
*d++ = *s++;
*d++ = *s++;
*d++ = *s++;
}
}
if (n & 1 << 1) {
*d++ = *s++;
*d++ = *s++;
}
if (n & 1)
*d++ = *s++;
return dest;
}
#else
/*
* Use word copies but no loop unrolling as we cannot assume there
* will be benefits on the archirecture
*/
void *memcpy(void *dest, __const void *src, __kernel_size_t n)
{
unsigned char *d, *s;
uint32_t *dest_w = (uint32_t *)dest, *src_w = (uint32_t *)src;
/* If both source and dest are word aligned copy words */
if (!((unsigned int)dest_w & 3) && !((unsigned int)src_w & 3)) {
for (; n >= 4; n -= 4)
*dest_w++ = *src_w++;
}
d = (unsigned char *)dest_w;
s = (unsigned char *)src_w;
/* For remaining or if not aligned, copy bytes */
for (; n >= 1; n -= 1)
*d++ = *s++;
return dest;
}
#endif
EXPORT_SYMBOL(memcpy);
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