FamilySearch has updated its Irish Civil Registration Index Collection. As is their way, they haven't chosen to enlighten us to the reason for the update or the origin of the nearly two million extra records that appear to have appeared!
The database says there are now 23,023,320 records within the collection (up from 21,090,790 records), so it might be worth taking another look in there if you've an ancestor that's proving elusive.
The indexes date from 1845 for marriages and from 1864 for births and deaths. They run to 1921 for all the island, but the records for 1922 to 1958 are for bmds in the Republic only.