[LLVMdev] [Polly] GSoC Proposal: Reducing LLVM-Polly Compiling overhead

[Sebastian Pop]

Star Tan wrote:
> >> #### Stage1 -- Set up a Polly performance tester to track the compile time. [Week 1]
> >>
> >> The first important work is to pick criteria to evaluate my work in
> >> this project. This project targets to reduce compile-time overhead,
> >> but at the same time it must not degrade the performance. To simplify
> >> the testing, I will use the number of scops that optimized by Polly as
> >> the performance criteria. As a result, our Polly performance tester
> >> should contains two parts:
> >>
> >> * Code performance: the number of scops optimized by Polly should not
> >> be degraded.
> >> * Compile-time Overhead: both the total compile-time overhead and the
> >> percentage of each Polly pass are both important.
> >>
> >> Furthermore, I currently use some scripts to collect the compile-time
> >> statistics, but it still requires some tricky and manual work. My plan
> >> is to set up an automation testing environment and integrate it into
> >> Polly.
> >
> >Yes, this is nice. It would be great if we could get some hardware to
> >run such tests regularly. I will check if we can find a sponsor for
> >this?

I will ask if we can have a machine to run a polly perf build-bot.

> Thank you. That would be great if we can find a sponsor.
> Otherwise, I think I have to run all test on my laptop.
> 

An alternative is to set up an automatic tester in the gcc compile farm
http://gcc.gnu.org/wiki/CompileFarm

and run the perf measurements on several different machines: collect all the
data and use a noise filter to discard any hiccups due to the use of the system
by another process, etc.

http://repo.or.cz/w/gcc-perf-regression-tester.git/blob_plain/HEAD:/analyze.R
http://repo.or.cz/w/gcc-perf-regression-tester.git/blob_plain/HEAD:/analyze-core.R

Note that even on a dedicated system you would have the same noise problem.

Sebastian
-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
hosted by The Linux Foundation