[llvm-commits] CVS: llvm/utils/TableGen/RegisterInfoEmitter.cpp

[Nate Begeman]

On May 1, 2007, at 2:03 PM, Christopher Lamb wrote:

> I see the problem in generating the ISel. Perhaps it would be be  
> best to go the other way and have the sub/super reg sets be  
> determined by the the explicit sets defined. My goal was simply to  
> eliminate redundant, and possibly erroneously conflicting  
> information from the file. Right now there are two different ways  
> to specify sub registers, and if they don't match there could be  
> problems.
>
>>
>>> Also, would it be possible to emit the information gathered as
>>> table lookups rather than a massive two level switch statement? I
>>> believe all the information to get the necessary mappings should be
>>> available.
>>
>> It would be possible, but seems like significantly more work.  I'm
>> sure it will be possible to improve upon the initial implementation,
>> which should be good enough to address most of the issues blocked by
>> the lack of subregs exposed to the selection dag.
>
> Thanks for working on this. I didn't expect to get it addressed for  
> quite a while!

No prob.  I appreciate the feedback; I'll definitely be keeping it in  
mind while I finish the rest of the bug.  Hopefully for 2.1 we can  
have everything done with no duplication of subreg info.

Thanks,
Nate