[llvm-dev] Inclusion of Polly and isl into core LLVM

Alex Elsayed via llvm-dev llvm-dev at lists.llvm.org
Mon Jan 22 17:45:32 PST 2018

On Tue, 23 Jan 2018 01:23:51 +0000, Alex Elsayed via llvm-dev wrote:

> On Mon, 15 Jan 2018 22:44:45 +0100, Tobias Grosser via llvm-dev wrote:
> <snip>
>>  * How stable/fast/… is Polly today
>>    * We build all of AOSP with rather restrictive compile-time limits *
>>    Bootstrapping time of clang is regressed by 6% (at most)
>>    * Removal of scalar dependences is today very generic and must be
>>      sped up in the future
>>    * Polly still shows up at the top of the middle-end, but larger
>>      compile time regressions are often due to increased code size (and
>>      the LLVM backend)
>>    * We see non-trivial speedups for hmmer, libquantum, and various
>>      linear-algebra kernels (we use gemm-specific optimizations). The
>>      first two require additional flags to be enabled.
> On the topic of performance, this paper might be of interest:
> Fast Polyhedral Abstract Domain
> Gagandeep Singh, Markus Püschel, Martin Vechev
> http://www.srl.inf.ethz.ch/papers/POPL17-Polyhedra.pdf
>> Our experimental results demonstrate massive gains in both space and
>> time: we show end-to-end speedups of two to five orders of magnitude
>> compared to state-of-the-art  Polyhedra implementations as well as
>> significant memory gains, on all larger benchmarks. In fact, in many
>> cases our analysis terminates in seconds where prior code runs out of
>> memory or times out after 4 hours.
> They compared against PPL and ELISA.

Gah, my mistake - they compared against NewPolka and PPL, and _their_ 
work was ELINA.

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