llvm dev - Aug 2014 - [LLVMdev] Tablegen: How to define a Pattern with multiple result instructions

Hi all,

I would like to be sure that Tablegen still does not support completely
separate multiple instruction generation, and the only way is to write
costume code (may be in TargetISelDAGToDAG class) to get the needed result.

Dear Tom, do you found other solution (using Tablegen tool) for this?

Thanks,
Arsen



--
View this message in context:
http://llvm.1065342.n5.nabble.com/Tablegen-How-to-define-a-Pattern-with-multiple-result-instructions-tp44115p71453.html
Sent from the LLVM - Dev mailing list archive at Nabble.com.

On Thu, Aug 14, 2014 at 12:05:33AM -0700, Arsen Hakobyan
wrote:
> Hi all,
> 
> I would like to be sure that Tablegen still does not support completely
> separate multiple instruction generation, and the only way is to write
> costume code (may be in TargetISelDAGToDAG class) to get the needed result.
> 
> Dear Tom, do you found other solution (using Tablegen tool) for this?
> 
I think the best way to do this is to use a pseudo instruction and then
expand it after instruction selection by using a custom inserter.

-Tom
> Thanks,
> Arsen
> 
> 
> 
> --
> View this message in context:
http://llvm.1065342.n5.nabble.com/Tablegen-How-to-define-a-Pattern-with-multiple-result-instructions-tp44115p71453.html
> Sent from the LLVM - Dev mailing list archive at Nabble.com.
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev

Dear Tom,

What is the advantage to use  the “pseudo instruction” approach VS “custom
lowering/DAGtoDAGSelection”  VS “ Library function”?

Best

Kevin



On Aug 14, 2014, at 9:27 AM, Tom Stellard <tom at stellard.net> wrote:
> On Thu, Aug 14, 2014 at 12:05:33AM -0700, Arsen Hakobyan wrote:
>> Hi all,
>> 
>> I would like to be sure that Tablegen still does not support completely
>> separate multiple instruction generation, and the only way is to write
>> costume code (may be in TargetISelDAGToDAG class) to get the needed
result.
>> 
>> Dear Tom, do you found other solution (using Tablegen tool) for this?
>> 
> 
> I think the best way to do this is to use a pseudo instruction and then
> expand it after instruction selection by using a custom inserter.
> 
> -Tom
> 
>> Thanks,
>> Arsen
>> 
>> 
>> 
>> --
>> View this message in context:
http://llvm.1065342.n5.nabble.com/Tablegen-How-to-define-a-Pattern-with-multiple-result-instructions-tp44115p71453.html
>> Sent from the LLVM - Dev mailing list archive at Nabble.com.
>> _______________________________________________
>> LLVM Developers mailing list
>> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
>> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev