Re: [PATCH 0/3] Move Graphite to CLooG 0.16.3 with isl backend.

[Tobias Grosser <tobias at grosser dot es>]

On 07/22/2011 10:08 AM, Richard Guenther wrote:
> On Fri, Jul 22, 2011 at 1:00 AM, Tobias Grosser<tobias@grosser.es>  wrote:
> > Hi,
> >
> > I propose to switch to the official cloog.org cloog version with isl backend and
> > at the same time to remove support for both CLooG-PPL legacy as well as
> > CLooG-Parma.
> >
> > We want to switch to cloog-isl as it is the only officially maintained version
> > of cloog. Furthermore, it provides features that will help to fix some bugs in
> > the graphite code generation[1].
> > The reason to abond CLooG-PPL (legacy version) is, that cloog-isl provides the
> > new CloogInput library interface. This interface is not available the old CLooG.
> > I plan to move graphite to this interface. As I do not see enough benefits from
> > being able to use CLooG PPL, I decided to not introduce any compatibility
> > scheme, but just remove any code that is only needed for CLooG-PPL.
> > I also removed CLooG-Parma (cloog.org with PPL backend), as it is currently not
> > actively maintained and not well tested. I believe our time is better spent on
> > improving graphite or cloog isl, as in putting time into this cloog version.
> >
> > So here we are: Moving graphite back to the official cloog.org version!
>
> Does that mean GCC no longer needs PPL?  If it is like today (we are going
> to link against both ISL and PPL) then I am opposed to this change.

No, this does not mean we do not need PPL anymore. Graphite itself still 
uses PPL. This change only affects the version of CLooG used.

This also means Graphite itself does for now not directly link to isl 
(at least it it is not a static build), as isl is only used in CLooG 
itself. It is also part of the official cloog-isl tar file, such that 
there is no need to download and install yet another library.

As you mentioned we may want to switch to use isl itself later, as it 
has some advantages over PPL, however this might be evaluated in a 
separate step.

Cheers
Tobi