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/**
** @file blkmov.c
**
** @author Numerous CSCI-452 classes
**
** @brief C implementations of common library functions
*/
#ifndef BLKMOV_SRC_INC
#define BLKMOV_SRC_INC
#include <common.h>
#include <lib.h>
/**
** blkmov(dst,src,len)
**
** Copy a word-aligned block from src to dst. Deals with overlapping
** buffers.
**
** @param dst Destination buffer
** @param src Source buffer
** @param len Buffer size (in bytes)
*/
void blkmov(void *dst, const void *src, register uint32_t len)
{
// verify that the addresses are aligned and
// the length is a multiple of four bytes
if ((((uint32_t)dst) & 0x3) != 0 || (((uint32_t)src) & 0x3) != 0 ||
(len & 0x3) != 0) {
// something isn't aligned, so just use memmove()
memmove(dst, src, len);
return;
}
// everything is nicely aligned, so off we go
register uint32_t *dest = dst;
register const uint32_t *source = src;
// now copying 32-bit values
len /= 4;
if (source < dest && (source + len) > dest) {
source += len;
dest += len;
while (len-- > 0) {
*--dest = *--source;
}
} else {
while (len--) {
*dest++ = *source++;
}
}
}
#endif
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