Meeting 01-07-2013

Contents

Present

SH, SC, JP, JB, Adam (Experience student)

Overview

SC presented a flow diagram of Compiler <--> MAGEEC <--> ML and what data is generated and exchanged where, and what the flow is. Will be on wiki.

Definition of features

  • Feature vectors need defining external to any compiler IR.
    • Some compilers may or may not have some features available.
    • The ML will need to ?regenerate? its data-sets for each option.
    • Define 'essential' + 'optional' features?
  • The feature vector needs to be defined.
    • MILEPOST vector is a starting point, but some features may not be useful.
    • Check with MILEPOST results.
    • Discarding features could speed the flow.
    • Are there language-specific features that are not so useful/a problem for future expandability?

Pass runs

  • Need to run sets of passes in one go, not just a single pass in one go.
    • Need to run lists of passes
    • How to bound the number sensibly
    • Some passes need to run multiple times (even after each other)
  • Can ML predict how many passes needed before starting?

ML predictor requirements

  • Takes in the current feature vector from a program with current passes run.
  • Needs to return back a list of passes to run next (with goodness metrics?)

ML Training

  • Probably use a separate application to do the training.
  • Need to generate sets of flags (randomly?) based on the constraints of pass ordering (shared data structure from the prediction phase)
  • Ordering of passes is important; can make a big difference in some cases.

Actions

  • SC Begin initial write of compiler->MAGEEC interfaces. Dummy ML placeholder for now.
  • SC Add list of upcoming meetings to wiki
  • SH Ensure that next meeting includes all ML people to get feedback into that aspect.
  • SH Apply for BlueCrystal Accounts for all
  • SH Inform all about quarterly meetings
  • SH Mailing list activation
  • MG Begin on defining the feature vectors to be used, based on MILEPOST.
  • JB Flag up with Tom Harris that the ~30% Q1-Q4 UoB staff budget will be rolled forward
  • KIE To decide on whether for two PCs with 32GB was one PC with two cores and much more RAM