Ugaritic

šmḫ - to be glad, rejoice (DUL 825)

PC
*ŝmḫ - to rejoice (Greenfield 1959: 151)
The origin is unclear, one cannot exclude (with Greenfield and Kopf 1976:190) an eventual relationship to PS *ŝmḫ ‘to be high, talľ (Kogan 2015: 307)