• Graphite_Phone_Call
• 2009_06_24

Attendees: Razya, Sebastian, Li, INRIA (Konrad, Ramakrishna, Denis), Antoniu, Jan, David, Tobias, Christophe

• Automatic tester:
  • gcc bootstrap, test suite and SPEC tester sent to gcc-graphite mailing list (Tobias, Sebastian)
  • TODO: Move this to gcc-testresults mailinglist.
  • Tobias will change the git tester to include the tested patch
• Automatic Parallelization:
  • Patch for loop carried data dependencies implemented. (Konrad, Li)
  • Patch for first implementation exists (working and bootstrapped) (Li)
    • Patch to be split into smaller patches
    • Will be committed this week (Li)
• PCP:
  • Working on integrating to CLooG and PPL.
    • get CLAST out and back to PCP
    • First PCP to PCP
  • GIMPLE to PCP seems simple (Jan)
    • Create a big testsuite
• Loop interchange:
  • Committed (Sebastian improv patch from Pranav).
  • 1 correctness bug in SPEC Cpu2006. Bug might be hidden by interchange heuristics
• Loop strip-mining:
  • Committed (Sebastian improved patch from Pranav).
  • 2 runtime bugs in SPEC Cpu2006.
  • Discussion about stride size.
    • At the moment constant factor of 64.
    • However a cost model would be useful. (David)
    • This will be implemented for loop blocking. (Sebastian)
• Reductions
  • Patch still WIP (Sebastian)
  • Special handlind for reductions in data dependencies to support autopar.
    • Idea 1: Ignore them totally (Razya)
    • Idea 2: Annotate data dependences with associativity and commutativity in Graphite (Sebastian)

  • How to annotate them in PCP. We have to consider whole cycles. See discussion on mailinglist (Razya)

• Parametric Integer Programming in PPL
  • Roberto, Abramo, Enea started develop an alternative to PIP
  • Work at INRIA to think about the algorithm. Not starting, but think about a new algorithm. Improve complexity of solver.
  • PPL should be usable in September.

  • Usage in GRAPHITE:Data dependences check. Computing size of tile.

• IV types:
  • Albert and Ramakrishna started yesterday.
  • Most issues expected in vectorizer.
  • Convert all to signed int before GRAPHITE. (What would be the impact to Graphite and vectorizer?) (Sebastian)
• Phone recording:
  • Idea: Record phone calls and host on wiki as reference. (Tobi)
  • No objections (All)