LOWER_MAX
if (find_first_bit(lower_chunk->data, LOWER_MAX) >= LOWER_MAX) {
lower = find_next_bit(lower_chunk->data, LOWER_MAX,
if (lower < LOWER_MAX)
#define LOWER_SIZE (LOWER_MAX / BITS_PER_LONG)
#define LOWER_MASK (LOWER_MAX - 1)