[Haskell-cafe] Does an unboxed unit get pushed to the stack?

[Tom Ellis]

On Thu, Jan 12, 2023 at 04:01:48PM +0100, Bertram Felgenhauer via Haskell-Cafe wrote:
> Tom Ellis wrote:
> > If I define bar and baz as below then, as I understand it, calling baz
> > requires pushing an argument onto the machine stack.  Is the same true
> > for baz, or is "calling" baz the same as "calling" foo, i.e. no
> > argument needs to be pushed?
> >     
> > 
> >     {-# LANGUAGE MagicHash #-}
> >     {-# LANGUAGE UnboxedTuples #-}
> >     
> >     module Bar where
> >     
> >     import GHC.Prim
> >     
> >     foo :: Int
> >     foo = 1
> > 
> >     bar :: (# #) -> Int
> >     bar (# #) = 1
> >     
> >     baz :: () -> Int
> >     baz () = 0
> 
> There is more to the story than just arguments. Assuming that nothing
> gets inlined

Very helpful, thank you!