EMPTY_REFERENCE_COUNT
if (count == EMPTY_REFERENCE_COUNT)
*counter_ptr = EMPTY_REFERENCE_COUNT;
word ^= temp * (PROVISIONAL_REFERENCE_COUNT ^ EMPTY_REFERENCE_COUNT);
split_count += match_bytes(word, EMPTY_REFERENCE_COUNT);
if (slab->counters[block_number] == EMPTY_REFERENCE_COUNT) {
VDO_ASSERT_LOG_ONLY((slab->counters[free_index] == EMPTY_REFERENCE_COUNT),