Re: [graphite] Weekly phone call notes

[Richard Guenther <richard dot guenther at gmail dot com>]

On Wed, Apr 29, 2009 at 11:34 PM, Tobias Grosser
<grosser@fim.uni-passau.de> wrote:
> Hi gcc developers, hi graphities
>
> here are some notes from our weekly phone call. Unfortunately I missed
> to send out the notes from the last two phone calls, but I hope to get
> them out more regulary. Believe in me! ;-)
>
> http://gcc.gnu.org/wiki/Graphite_Phone_Call/2009_04_29
>
> Attendees: Li, Jan, Konrad, Sebastian, Tobias, David, Christophe
>
> ? ? ?* Reductions: Diego OK with going out of SSA.

You will loose all points-to information.  I think going out of SSA is
a very bad idea.

Richard.

> ? ? ? ? ? ? ?* Patch not yet ready. The higher code coverage exposes an
> ? ? ? ? ? ? ? ?IVSTACK bug.
> ? ? ?* IVStack: Sebastian is working on removing it
> ? ? ?* Data dependence analysis: Committed to graphite branch.
> ? ? ? ? ? ? ?* Not yet enabled, as the data reference still does not
> ? ? ? ? ? ? ? ?bootstrap. The lexicographic smaller than constraint is
> ? ? ? ? ? ? ? ?not yet added. This is not wrong but very conservative.
> ? ? ? ? ? ? ? ?Dependence test should be enabled with
> ? ? ? ? ? ? ? ?-fgraphite-identity.
> ? ? ?* Loop transformations: We need some simple transformations to
> ? ? ? ?check data dependency analysis.
> ? ? ? ? ? ? ?* Pranav? We did not hear anything yet.
> ? ? ?* Data reference: Last bugs have to be fixed.
> ? ? ? ? ? ? ?* Not yet enabled. Blocks data dependence analysis.
> ? ? ?* PCP:
> ? ? ? ? ? ? ?* Jan Implemented simplification/canonicalization for
> ? ? ? ? ? ? ? ?expressions. This will allow a systematic translation of
> ? ? ? ? ? ? ? ?expressions to constraints. Jan will work on a reduced
> ? ? ? ? ? ? ? ?polyhedral interface that is used in PCP. First PCP
> ? ? ? ? ? ? ? ?integration in gcc - later extended by reductions.
>
> ? ? ? ? ? ? ? ?No good representation for reductions for the general
> ? ? ? ? ? ? ? ?case. Like conditions and PHI nodes (Sebastian) Maybe
> ? ? ? ? ? ? ? ?for a subset of the reductions we can add commutativaty
> ? ? ? ? ? ? ? ?of operations.
>
> ? ? ?* Autopar: Li prepared some patches to trigger autopar by
> ? ? ? ?graphite.
> ? ? ? ? ? ? ?* Autopar failed in the graphite branch even without
> ? ? ? ? ? ? ? ?graphite enabled. It seems we introduced a bug while
> ? ? ? ? ? ? ? ?using some code of it for graphite. The breakage happens
> ? ? ? ? ? ? ? ?in the reductions part.
> ? ? ?* Merge from trunk:
> ? ? ? ? ? ? ?* Sebastian wants to work on this Changes in vectorizer
> ? ? ? ? ? ? ? ?Last merge 4 months ago Tried mid march but was
> ? ? ? ? ? ? ? ?difficult. So stopped because of ENOTIME.
> ? ? ?* Parts of graphite working well?: The polyhedral part of the
> ? ? ? ?graphite architecture will be described
> ? ? ? ? ? ? ?* in the Tobias' paper at the summit and the PCP part by
> ? ? ? ? ? ? ? ?Jan.
> ? ? ?* Worldwide interest: Cristianno Martins from Brazil showed some
> ? ? ? ?interest
> ? ? ? ? ? ? ?* http://gcc.gnu.org/ml/gcc/2009-04/msg00711.html
>
> ? ? ? ? ? ? ?* We already have people from the US, Europe and China
> ? ? ? ? ? ? ? ?contributing.
>
>
>
>