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Re: Graphite: Collapsing of loop nests ?
On Fri, Dec 4, 2009 at 10:39, Tobias Grosser <grosser@fim.uni-passau.de> wrote:
> I do not believe this is already possible for arbitrary N.
>
> You would have to write a scattering function like this
>
> s0 = i+n*(j-1)
>
> What is
>
> s= i + n*j - n
> Â Â Â ^^^ ÂHere is a product that is not affine linear.
Yes this is affine linear, but not representable in the current way we
deal with parameters in the polyhedral model... Note that constant
times IV would be allowed, and yes parameters are named constants.
> There are extensions to the polytop model to make this possible, but
> they are not close to be production ready.
I think that we should revisit this independently of general solutions.
> Just recently I Armin Groesslinger gave a nice talk about this
> topic. If you want I can look for his work describing solutions.
I also have discussed with Armin when I was visiting INRIA earlier
this year, and I know what he's working on.
Sebastian