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/*
* Copyright (c) 2013-2018, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <string.h>
void *memmove(void *dst, const void *src, size_t len)
{
/*
* The following test makes use of unsigned arithmetic overflow to
* more efficiently test the condition !(src <= dst && dst < str+len).
* It also avoids the situation where the more explicit test would give
* incorrect results were the calculation str+len to overflow (though
* that issue is probably moot as such usage is probably undefined
* behaviour and a bug anyway.
*/
if ((size_t)dst - (size_t)src >= len) {
/* destination not in source data, so can safely use memcpy */
return memcpy(dst, src, len);
} else {
/* copy backwards... */
const char *end = dst;
const char *s = (const char *)src + len;
char *d = (char *)dst + len;
while (d != end)
*--d = *--s;
}
return dst;
}
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