{
	my @targ_shift = (
		\$a,  0,
		\$a,  8,
		\$a, 16,
		\$a, 24,
		\$b,  0,
		\$b,  8,
		\$b, 16,
		\$b, 24,
		\$c,  8,
		\$c, 16,
		\$c, 24,
	);

	for (0 .. $len-1) {
		my ($targ, $shift) = splice @targ_shift, 0, 2;
		$$targ += $k[$_] << $shift;
	}
}