The intestate share of the surviving spouse is:
(1) If there is no surviving descendant of the decedent, the entire intestate estate.
(2) If the decedent is survived by one or more descendants, all of whom are also descendants of the surviving spouse, and the surviving spouse has no other descendant, the entire intestate estate.
(3) If there are one or more surviving descendants of the decedent who are not lineal descendants of the surviving spouse, one-half of the intestate estate.
(4) If there are one or more surviving descendants of the decedent, all of whom are also descendants of the surviving spouse, and the surviving spouse has one or more descendants who are not descendants of the decedent, one-half of the intestate estate.