> On Jun 19, 2020, at 12:54 PM, Remi Forax <fo...@univ-mlv.fr> wrote:
>
>> Note that [I and [QInteger$val have the exact same layout, so it is really a
>> matter of treating the two type names as referring to the same underlying
>> runtime type.
>
> yes, but at the same time descriptor are matched by name and you need to have
> the proper descriptor when overriding/implementing a method,
> so the strategy of blindly replacing every I by QInteger$val; doesn't really
> work.
>
> Usually the solution is to use bridges but bridges only work with subtyping
> relationship not equivalence relationship (because you can travel in both
> direction).
> I believe we need to bring the forward/bridge-o-matic at the same time we
> retrofit primitive to inline.
In the VM this is mostly a verification problem: have a
'[Qjava/lang/Integer$val;', need a '[I'? You're good! ("Mostly", because there
is still the matter of ensuring there's a single encoding for both kinds of
objects, or that the instructions are capable of handling two different
encodings.)
I'm not sure we'd get into any situations where a '([I)V' descriptor needs to
override a '([Qjava/lang/Integer$val)V' descriptor, or vice versa, until we get
to specialization, and then I'm not sure this is any different than other forms
of bridging. All existing code will continue to use 'I' in its compiled
descriptors.
