Improvement of vectorization on loops generated by Graphite

[Sebastian Pop]

On Tue, Jul 27, 2010 at 21:09, Jack Howarth <howarth@bromo.med.uc.edu> wrote:
>    When do you think we may start to see the vectorizations in
> Gr1 exceed those from Gr0?

I know at least of one case http://gcc.gnu.org/PR43423 that is still
not vectorized and that would benefit of the -fgraphite-identity (that
does iteration domain splitting).

I am also working on a techniques for aggressive if-conversion of
nested loops using Graphite.

On all these cases, I have to make sure that the code produced by
Graphite can be vectorized.

> Will that required upgrading to the newer cloog?

Not necessarily.

At one point in time I would like to stop maintaining the CLooG-PPL
branch and switch completely to CLooG.org.  That will probably happen
in the 4.7 timeline, if we can show that CLooG.org is stable and
produces better code by then.

>            Jack
> ps If the vectorizations using -fgraphite-identity eventually reaches
> parity with those without that option, would -fgraphite-identity
> become defaulted on for gcc builds with graphite support
> (assuming minimal compile time increases)?

We'll have to show the benefits of turning that flag on.

Sebastian