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. * 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.
