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

Sebastian Pop spop at codeaurora.org
Fri May 3 11:24:41 PDT 2013

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

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.


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

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