Here are median values based on a few trial runs with -Os (but I'm still building and running for MacOSX only).

Int/int : Swift = 2.7s, ObjC = 3.4s (Swift is 25% faster)

Int64/int64_t : Swift = ObjC = 2.7s (indistinguishable)

edit: Swift compiler is still building in "fastest unchecked" mode for both.