[llvm-dev] [GSoC 2016] Implementation of the packing transformation

[Roman Gareev via llvm-dev]

2016-06-29 13:02 GMT+05:00 4lbert C0hen <4lbert.h.c0hen at gmail.com>:
> On 06/28/2016 10:53 AM, Roman Gareev wrote:
>>
>> 2016-06-27 15:52 GMT+05:00 4lbert C0hen <4lbert.h.c0hen at gmail.com>:
>>>
>>> Dear Roman and all,
>>>
>>> Such features would be extremely useful to implement array expansion
>>> (scalar
>>> and array renaming, privatization with new subscript expressions of
>>> higher
>>> dimension) and storage mapping optimization (generalizing array
>>> contraction). It would be interesting to have these future applications
>>> in
>>> mind when working on the packing transformation.
>>
>>
>> Thank you for the comment! Could you please advise me where I can find
>> definitions of array expansion and storage mapping optimization?
>>
>> I've found the following papers that are probably related to this: [1]
>> and [2]. However, maybe I missed something.
>>
>> Refs.:
>
>
>> [1] -
>> http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.29.5704&rep=rep1&type=pdf
>
> Yes, this is one of the must-read papers for any polyhedral compilation
> work!
>
> The following is a generalization to approximate array dataflow (journal
> extension of a POPL 1998 paper)
> http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.26.6376&rep=rep1&type=pdf
> Rather theoretical, and can be simplified to not make explicit usage of
> transitive closure computations. There is much research to be done in the
> area, with short term applications and implementation in production. E.g.,
> on-demand expansion on top of the Live Range Reordering technique
> implemented in isl and PPCG (papers and slides below):
> http://impact.gforge.inria.fr/impact2016
>
>> [2] - https://hal.archives-ouvertes.fr/hal-01257316/document
>
> That one is rather specific to parallel programs and also theoretical.
>
> State of the art:
>
> - POPL 2016
> http://conf.researchr.org/event/POPL-2016/popl-2016-papers-smo-an-integrated-approach-to-intra-array-and-inter-array-storage-optimization
> http://dl.acm.org/citation.cfm?id=2837636
>
> There is a tool available but it has received little publicity yet:
> https://github.com/bondhugula/smo
> Yet the input is in for of polyhedral sets/maps, not code.
>
> - CC 2016, Darte, Isoard, Yuki
> https://www.conference-publishing.com/list.php?Event=CC16
> Better heuristic. Currently limited to single-array SMO.
>
> Again, much potential for research and implementation.
>
> I'll be glad to discuss transfer of these results to Polly, as well as
> Alexandre, Uday and others on this list.
>

Thank you for the information! I'll try to take these applications into account.

-- 
                                    Cheers, Roman Gareev.