boolean inSameSubroutine(final Label block) {
		if ((status & VISITED) == 0 || (block.status & VISITED) == 0) {
			return false;
		}
		for (int i = 0; i < srcAndRefPositions.length; ++i) {
			if ((srcAndRefPositions[i] & block.srcAndRefPositions[i]) != 0) {
				return true;
			}
		}
		return false;
	}