[LLVMdev] [LLVMDev] Add not instruction to PTX backend

[Justin Holewinski]

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
>
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>



-- 

Thanks,

Justin Holewinski
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