Guys, are all of you missing this? Due to the Pascal calling convention, the first (plain!) argument of a function maps into the same register(s), so in fact this is valid and correct code. Though strictly I agree it looks weird and like as if in 'normal' cases the Value members aren't assigned to Result members. Bit in fact, they're already there! So what is actually needed is a 'type size limiting' cast, which is exactly what Result.x:=SmallInt(Result.x); is.