[LLVMdev] Tile64 bundle-types and VLIW infrastructure

[Julien Peeters]

Hi David,

I am working on a TilePro 64, so I am very interested in your
back-end. Is it released as open source?

Furthermore, I had a discussion on this ML some months ago about the
writing of a back-end for the Tile processor. Maybe that several
people would be interested in helping you enhance your work.

Best,
Julien.

On 17 July 2012 12:22, Juhasz David <juhda at inf.elte.hu> wrote:
> Hello,
>
> I've made a backend for Tile64 processor as my master's thesis. Of
> course, there is a lot to do in order to harness all the power of the
> processor, but LLVM programs already can be compiled to tile assembly.
> If anyone interested in the backend, just let me know and I release the
> code on our project site.
>
> One way to improve my backend is to utilize its ILP capabilities, so
> I'd really like to use the new VLIW infrastructure of LLVM 3.1. My
> problem is the following:
>
> The processor consists of three parallel pipelines, however there are
> two types of bundles: two-wide (X) and three-wide (Y) bundles. All of
> the instructions can packed into X-bundles, but using Y-bundles would
> be more efficient. Too bad, Y-bundles can't contain arbitrary
> instructions.
>
> So, there are 5 virtual pipelines: X0, X1, Y0, Y1, Y2. I can define
> that which pipelines can be used to perform an instruction. On the
> other hand, AFAIK one subtarget can be matched only with one
> ProcessorItineraries and all its FuncUnits may be used in each bundle.
> Thus, I can't constraint bundles to use either X0, X1 or Y0, Y1, Y2, and
> never mix them.
>
> Is there a way to define two types of bundles using the current
> capabilities of TableGen and CodeGen? Or had I better use only X-bundles
> for now?
>
> Thanks for any suggestions,
> David
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev



-- 
PhD student in Electronics and Embedded systems
LinkedIn profile : http://www.linkedin.com/in/julienpeeters
Viadeo profile : http://www.viadeo.com/fr/profile/julien.peeters
Website : http://www.julienpeeters.net