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/*
* Copyright 2010 Tilera Corporation. All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation, version 2.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
* NON INFRINGEMENT. See the GNU General Public License for
* more details.
*/
#include <linux/types.h>
#include <linux/string.h>
#include <linux/module.h>
void *memmove(void *dest, const void *src, size_t n)
{
if ((const char *)src >= (char *)dest + n
|| (char *)dest >= (const char *)src + n) {
/* We found no overlap, so let memcpy do all the heavy
* lifting (prefetching, etc.)
*/
return memcpy(dest, src, n);
}
if (n != 0) {
const uint8_t *in;
uint8_t x;
uint8_t *out;
int stride;
if (src < dest) {
/* copy backwards */
in = (const uint8_t *)src + n - 1;
out = (uint8_t *)dest + n - 1;
stride = -1;
} else {
/* copy forwards */
in = (const uint8_t *)src;
out = (uint8_t *)dest;
stride = 1;
}
/* Manually software-pipeline this loop. */
x = *in;
in += stride;
while (--n != 0) {
*out = x;
out += stride;
x = *in;
in += stride;
}
*out = x;
}
return dest;
}
EXPORT_SYMBOL(memmove);
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