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  23   <h1>Open Projects</h1>
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  25
  26   LLVM Polly keeps here a list of open projects which each of themselves would
  27   be a great contribution to Polly. All of these projects are meant to be self
  28   contained and should take a newcomer around 3-4 months of work. The projects
  29   we propose are all suiteable as <a
  30   href="https://developers.google.com/open-source/gsoc/">Google Summer of
  31   Code</a> projects. In case you are interested in a Google Summer of code
  32   project make sure to reach out via the Polly <a
  33   href="http://groups.google.com/group/polly-dev">mailing list</a> early to
  34   discuss your project proposal.
  35
  36   <h3>Integrate Polly with the LLVM vectorizers</h3>
  37   Polly is not only a self-contained optimizer, but also provides a powerful
  38   dependence and other program analyses. Currently, these analyses are only used
  39   for our own optimizations. However, LLVM passes such as the loop vectorizer
  40   would clearly benefit from having direct access to the available Polly
  41   analyses. In this project, you would define in collaboration with the LLVM
  42   community and considering existing dependence analysis interface a new
  43   dependence analysis interface for Polly that allows passes to directly query
  44   Polly analysis. Even though this project sounds straightforward at a first
  45   glance, sorting out how to actually make this happen with the current and
  46   the new pass managers, understanding how and when to invalidate the Polly
  47   analysis and if dependence information can be computed on-demand make this
  48   still a challenging project. If successful, this project may be a great way
  49   to bring features of Polly to standard -O3 optimizations.
  50
  51   <h3>Register tiling to obtain fast BLAS kernels with Polly</h3>
  52   Even though Polly is already able to speep up compute kernels significantly,
  53   when comparing to the best BLAS routines we still are at least one order of
  54   magnitude off. In this project you will investigate what is needed to close
  55   this performance gap. Earlier investigations have shown that register tiling
  56   is one important piece towards this goal. In combination with good tile size
  57   models and some back-end work, this project is shooting to make common blas
  58   operations, but also many non-blas kernels competitive with vendor math
  59   libraries and outperforming the code icc/gcc currently generate.
  60
  61   <h3>Polly support for Julia - First steps</h3>
  62   <a href="http://julialang.org/">Julia</a> is a new matlab style programming
  63   language that provides C like performance for scientific computing. Even
  64   though Julia also translates to LLVM-IR, parsing and optimizing Julia code
  65   poses new challenges that currently prevent Polly from optimizing Julia
  66   code despite the clear need for optimizations such as loop-tiling for Julia.
  67   In this project you will -- starting from first proof-of-concept patches --
  68   integrate Polly into Julia and ensure that Julia code can benefit from the
  69   same high-level loop optimizations as todays C code already does. If time
  70   permits, making Polly's recent bound-check elimination logic work in Julia
  71   code would allow the optimization of Julia code, even if save out-of-bound
  72   checking is used.
  73   <h3>Interactive Polyhedral Web Calculator</h3>
  74   At the core of Polly we use the isl math library. isl allows us to describe
  75   loop transformations with relatively simple higher level operations while
  76   still providing the full expressiveness of integer polyhedra. To understand
  77   and describe the transformations we are performing it is often very convenient
  78   to quickly script example transformations in a scripting language like python.
  79   isl already comes with a python binding generator, with
  80   pypyjs there is a python interpreter for the web and with emscriptem isl
  81   itself can also be compiled to javascript. In this project you combine all
  82   these components to obtain an interactive polyhedral web calculator, that uses
  83   latest web technology to nicely illustrate the integer polyhedra you obtain.
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