call to __Value methods can't pass fields as arguments

[Frederic Parain]

Roland,

Cannot we use T_VALUETYPE instead of T_OBJECT?

Fred


> On Mar 24, 2017, at 11:08, Roland Westrelin <rwestrel at redhat.com> wrote:
> 
> 
> Hi Fred,
> 
> Thanks for looking at this.
> 
>> Thank you for finding this issue with the __Value methods,
>> 
>> I’m concerned with changes in sharedRuntime.cpp:2607:
>> 
>> 2605           ValueKlass* vk = ValueKlass::cast(holder);
>> 
>> 2606           if (vk == SystemDictionary::___Value_klass()) {
>> 2607             sig_extended.push(SigEntry(T_OBJECT));
>> 2608           } else {
>> 
>> 2609             const GrowableArray<SigEntry>& sig_vk = collect_fields(vk);
>> 2610             sig_extended.appendAll(&sig_vk);
>> 
>> 2611           }
>> 
>> Is it trying passing a reference to a standalone value by pretending that it is
>> an Object?
> 
> It is not. It's recording that a _Value should be passed as a reference
> so the logic that performs the allocation of arguments to registers
> picks up a register that can hold a reference. Using T_OBJECT here is
> ugly. It should probably be revisited. I'll add a comment.
> 
> Roland.