About Polly
Polly is a polyhedral optimizer for LLVM. Using an abstract mathematical representation it analyzes and optimizes the memory access pattern of a program. This includes data-locality optimizations for cache locality as well as automatic parallelization for thread-level and SIMD parallelism. Our overall goal is an integrated optimizer for data-locality and parallelism that takes advantage of multi-cores, cache hierarchies, short vector instructions as well as dedicated accelerators.
See polyhedral.info for general information about polyhedral compilation.
News
2014 | |
February |
Polly presentation at FOSDEM 2014Polly was presented at the FOSDEM LLVM developer's meeting.New LLVM test-suite buildbotsThe set of Polly buildbots has been extended. We now have 16 new blades that track correctness and performance when compiling the LLVM test-suite. For now five of of them are used to provide fine granularity reports (almost per-commit) for 'clang -O3' (no polly). We also have six machines that track different configurations of polly. |
January |
islplot releasedislplot is a library that generates illustrations of integer sets and maps. It relies on isl to model the integer sets and uses the islpy Python bindings to access them. Plotting is performed with matplotlib. The following Examples show its use. |
2013 | |
November |
Loop optimization BoF at upcoming LLVM conferenceAt the upcoming LLVM conference there will be a loop optimization BoF discussing Polly and other high level loop optimizers. |
October |
Automatic code coverage and static analysis testsSylvestre Ledru set up automatic tests for code coverage and static analysis which run at least once a day and which include results for Polly.Move to CLooG 0.18.1 and isl 0.12.1With the move to an isl 0.12 version Polly can be compiled without the need to link directly to GMP (if isl is used for code generation). Currently isl is still internally using GMP, but private patches exist to also remove this dependency. Without the use of GMP, a GPL free version of Polly is possible. |
2012 | |
December |
New publication in the PPL JournalWe published a journal version of the Polly paper named Polly - Performing polyhedral optimizations on a low-level intermediate representation in the Parallel Processing Letters 2012. |
September |
Experimental support for the new isl code generatorThe code generator can be parameterized on a fine-grained level. It gives direct control for example over unrolling, the amount of control overhead and the code size. It can also be used to create loops to handle border conditions or to perform full-partial tile separation.We also relicensed isl under the MIT license. This means, with the exception of GMP (LGPL), there is no other (L)GPL licensed software used in Polly. The use of GMP is limited to a well defined interface. Replacing it with a BSD licensed replacement is a tractable engineering project we would be very interested in. For more information about isl see the isl manual. |
July |
Polly can now be directly linked to the Pluto optimizer. We were
already able to perform Pluto-like optimizations with Polly, as a similar
algorithm was added to isl half a year ago. However, being able to directly
compare with the original implementation will not only bring in competition in
the optimizer field. It will also allow new experiments with a cutting edge
research tool. |
February |
Polly is an official LLVM project, reachable at http://polly.llvm.org |
January |
Improved support for the isl scheduling optimizer Polly can now automatically optimize all polybench 2.0 kernels without the help of an external optimizer. The compile time is reasonable and we can show notable speedups for various kernels. |
2011 | |
November |
Talk at the LLVM Developer Meeting 2011 New SCEV parser(Allows parameters in array subscript and max/signextend) |
October |
Polly can use the isl schedule optimizer |
August |
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July |
Polly builder as part of the LLVM Buildbots |
June |
Tobias is founded for three years by a Google Europe Fellowship in Efficient Computing. |
May |
Tobias' diploma thesis and Raghesh's master thesis. See our list of publications. |
April |
Polly moves to the LLVM infrastructure (svn, bugtracker) |
March |
Presentation at CGO/IMPACT Polly can compile polybench 2.0 with vectorization and OpenMP code generation |
Februar |
pollycc - a script to automatically compile with polyhedral optimizations |
Januar |
Basic OpenMP support, Alias analysis integration, Pluto/POCC support |
2010 | |
Dezember |
Basic vectorization support |
November |
Talk at the LLVM Developer Meeting |
October |
Dependency analysis Finished Phase 1 - Get something working Support scalar dependences and sequential SCoPs |
August |
RegionInfo pass committed to LLVM llvm-test suite compiles |
July |
Code generation works for normal SCoPs. |
June |
OpenSCoP import/export works (as far as openscop is finished). |
May |
The CLooG AST can be parsed. |
April |
SCoPs can automatically be detected. |
March |
The RegionInfo framework is almost completed. |
February |
Translate a simple loop to Polly-IR and regenerate a loop structure with CLooG works. ISL and CLooG are integrated. |
January |
The RegionInfo pass is finished. |
2009 | |
End of the year |
Work on the infrastructure started. |