Re: [graphite] Backend fixes

[Tobias Grosser <grosser at fim dot uni-passau dot de>]

Hi Jack,

> Tobias,
>      The situation regarding code generation from graphite is still a bit confusing.
> Sebastian left me with the impression that the bottleneck preventing the backend
> from generating code from the new loop optimizations in graphite was the absence
> of simplification operation in ppl. I also was given the impression that code
> generation would work fine with cloog/graphite/polylib since it already had the
> simplification operation. You proposed patch seems to indicate that graphite wasn't
> really wired up to generate code in the back end at all yet. Is that a correct
> reading of the situation?
The situation is like this (as I see it, so please correct me, if I am
wrong)

Our backend supported a limited extend of the graphite representation
and was designed to be extended. The main missing part (that Jan
committed on Saturday) was support for conditional statements, as they
where not necessary for simple loops we wanted to loop block.

The problem with cloog-ppl was, that this port always generated useless
conditions in every loop nest. So we where not able to generate any
code.

This situation has improved much, as I sent Sebastian a mail that fixes
cloog (I hope he commits this soon) and Jan has added condition support
on Saturday.

So the main problem seems to be fixed.

> Also, is it correct to say that graphite's code generation
> was always designed to be done by converting the GIMPLE to GRAPHITE representations,
> processing these with ppl/cloog and reconverting the results back into GIMPLE for
> final code generation?
Yes seems correct. At least for my last year in graphite.

See you
Tobi