memmove.c

The main purpose of this project is to add a new scheduling algorithm to GeekOS and to implement a s

/***********************************************************
Copyright 1991-1995 by Stichting Mathematisch Centrum, Amsterdam,
The Netherlands.

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/* A perhaps slow but I hope correct implementation of memmove */

#include <string.h>

void *
memmove(void *d, const void *s, size_t n)
{
	char *dst = (char*) d;
	const char *src = (const char*) s;
	char *realdst = dst;
	if (n <= 0)
		return dst;
	if (src >= dst+n || dst >= src+n)
		return memcpy(dst, src, n);
	if (src > dst) {
		while (--n >= 0)
			*dst++ = *src++;
	}
	else if (src < dst) {
		src += n;
		dst += n;
		while (--n >= 0)
			*--dst = *--src;
	}
	return realdst;
}