hash_t memhash(const void *ptr, size_t len)
{
	const byte *s = (byte *)ptr;
	dword val = HASH32_CONST1;
	if(len >= 4) {
		if(len >= 16) {
			dword val1, val2;
			val1 = val2 = HASH32_CONST1;
			while(len >= 8) {
				val1 = HASH32_CONST2 * val1 + *(dword *)(s);
				val2 = HASH32_CONST2 * val2 + *(dword *)(s + 4);
				s += 8;
				len -= 8;
			}
			val = HASH32_CONST2 * val + val1;
			val = HASH32_CONST2 * val + val2;
		}
		const byte *e = s + len - 4;
		while(s < e) {
			val = HASH32_CONST2 * val + *(dword *)(s);
			s += 4;
		}
		return HASH32_CONST2 * val + *(dword *)(e);
	}
	if(len >= 2) {
		val = HASH32_CONST2 * val + *(word *)(s);
		val = HASH32_CONST2 * val + *(word *)(s + len - 2);
		return val;
	}
	return len ? HASH32_CONST2 * val + *s : val;
}