llvm dev - May 2011 - [LLVMdev] [LLVMDev] Add not instruction to PTX backend

Hi, Dan

  Someone on the irc suggest me using custom lowering to do the mapping
correctly. But I am still trying to figure out how to do that.

Regards,
chenwj

-- 
Wei-Ren Chen (陳韋任)
Computer Systems Lab, Institute of Information Science,
Academia Sinica, Taiwan (R.O.C.)
Tel:886-2-2788-3799 #1667

On Thu, May 12, 2011 at 9:56 PM, 陳韋任 <chenwj at iis.sinica.edu.tw> wrote:
> Hi, Dan
>
>  Someone on the irc suggest me using custom lowering to do the mapping
> correctly. But I am still trying to figure out how to do that.
>
Custom lowering means implementing the SelectionDAG instruction selection in
the C++ class instead of the TableGen file.  See PTXISelLowering.{h,cpp} for
some examples.  This just allows arbitrary matching and code generation
logic instead of just pattern matching.

Though, I have to agree with Dan on assessing whether the selection logic is
needed.  Do you have an example where the PTX back-end cannot generate code
for some piece of LLVM IR because of the lack of 'not' selection?

>
> Regards,
> chenwj
>
> --
> Wei-Ren Chen (陳韋任)
> Computer Systems Lab, Institute of Information Science,
> Academia Sinica, Taiwan (R.O.C.)
> Tel:886-2-2788-3799 #1667
>
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>


-- 

Thanks,

Justin Holewinski
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> Though, I have to agree with Dan on assessing whether the selection logic
is
> needed.  Do you have an example where the PTX back-end cannot generate code
> for some piece of LLVM IR because of the lack of 'not' selection?
  Honestly, I don't have such example yet. Just want to try to implement
some instructions by myself. :p

Regards,
chenwj

-- 
Wei-Ren Chen (陳韋任)
Computer Systems Lab, Institute of Information Science,
Academia Sinica, Taiwan (R.O.C.)
Tel:886-2-2788-3799 #1667