void addToSubroutine(final long id, final int nbSubroutines) {
		if ((status & VISITED) == 0) {
			status |= VISITED;
			srcAndRefPositions = new int[(nbSubroutines - 1) / 32 + 1];
		}
		srcAndRefPositions[(int) (id >>> 32)] |= (int) id;
	}