[MLton] refs in ssa

[Matthew Fluet]

> > Can you post some code that demonstrates this?  I'd be very surprised if
> > this were the case.

I actually meant could you post some code that when compiled you see
Ref_ref being applied to multiple arguments.

>  | PrimApp{prim, targs, args} =>
>         (case var of
>                SOME var' => ...
>            (case Prim.name prim
>               of Ref_ref =>
>                   let val i = Vector.length(args)
>                       val _ = print(Int.toString i)
>                       val _ = if i = 0 then ()
>                               else setRefEnv(var', {var = Vector.sub(args, 0)})
>                       val _ = print("\n")
>                   in [stmt]
>                   end
>              | _ => [stmt])

I'd check this code -- are you sure that "..." in the third line doesn't
define a variable named args that is being used within the Ref_ref case?

> skavena 107 $ ./mlton -flatten true zebra.batch.sml

When I look at zebra.flatten.pre.ssa and zebra.flatten.post.ssa, then
every Ref_ref is applied to exactly one argument.