twhitehead:
> Consider the following code
>
> data Data = Data { unData :: !Int }
>
> func :: Data -> Int
> func x = case unData x of
> 1 -> 2
> _ -> 0
>
> Compiling with GHC 6.8.2 gives the following stg code
>
> Main.func =
> \r [x_slg]
> case x_slg of tpl_slx {
> Main.Data ipv_slj ->
> case ipv_slj of wild_sly {
> GHC.Base.I# ds_slm ->
> case ds_slm of ds1_slz {
> __DEFAULT -> Main.lvl1;
> 1 -> Main.lvl;
> };
> };
> };
Note that using -funbox-strict-fields helps,
A.func :: A.Data -> Int
A.func =
\ (x_afx :: A.Data) ->
case x_afx of tpl_B2 { A.Data rb_B4 ->
case rb_B4 of ds_Xg7 {
__DEFAULT -> A.lvl1
1 -> A.lvl }
}
No I#.
I'd expect if 'func' was inlined, for the return to be unboxed as well.
-- Don
_______________________________________________
Glasgow-haskell-users mailing list
Glasgow-haskell-users@haskell.org
http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
