view Python/memmove.c @ 23305:ef6e31f0cee1 legacy-trunk

builtin_zip(): Take a good guess at how big the result list will be, and allocate it in one gulp. This isn't a bugfix, it's just a minor optimization that may or may not pay off.
author Tim Peters <tim.peters@gmail.com>
date Mon, 29 Apr 2002 21:27:32 +0000
parents 6f6f965c5e2d
children
line wrap: on
line source


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

extern char *memcpy(char *, char *, int);

char *
memmove(char *dst, char *src, int n)
{
	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;
}