Review request: Zero assembler port of HotSpot

Tom Rodriguez Thomas.Rodriguez at Sun.COM
Tue Sep 22 22:20:52 PDT 2009

>> I'm going to look into making it work the way I want.  The logic is
>> mainly driven through buildtree.make and I recently was experimenting
>> with driving that differently so I think I can see how to do it.   
>> I'll
>> take a stab and get back to you.  If I can't then linux_zero_zero  
>> will
>> have to do.
> I'll make a new webrev so you can work on the partially right one.


> So it's just a dummy frame to make the idiom below work?
>>    frame stub_frame = thread->last_frame();
>>    frame caller_frame = stub_frame.sender(&reg_map);
> Yes.  Maybe it would be better to rename DEOPTIMIZER_FRAME as
> something like EMPTY_FRAME or DUMMY_FRAME?

Yes.  Maybe dummy stub frame to be explicit?

>> Do you insert dummy stub frames to deal with other places that use
>> that idiom or are you not using entry points that have that pattern?
> There's nowhere else in Zero or Shark that creates dummy frames like
> this.

So I guess this means you never use any of the other compiled stub  
entry points.  Maybe the deopt entry points could be refactored so  
shark doesn't need a fake frame.  Would that make sense?


> Cheers,
> Gary
> -- 

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