On Mon, Dec 5, 2016 at 12:00 PM Moritz Angermann
Hi,
I’ve started the GHC Performance Regression Collection Proposal[1] (Rendered [2]) a while ago with the idea of having a trivially community curated set of small[3] real-world examples with performance regressions. I might be at fault here for not describing this to the best of my abilities. Thus if there is interested, and this sounds like an useful idea, maybe we should still pursue this proposal?
Cheers, moritz
[1]: https://github.com/ghc-proposals/ghc-proposals/pull/26 [2]: https://github.com/angerman/ghc-proposals/blob/prop/perf-regression/proposal... [3]: for some definition of small
Interesting! I must have missed this proposal. It seems that it didn't meet with much enthusiasm though (but it also proposes to have a completely separate repo on github). Personally, I'd be happy with something more modest: - A collection of modules/programs that are more representative of real Haskell programs and stress various aspects of the compiler. (this seems to be a weakness of nofib, where >90% of modules compile in less than 0.4s) - A way to compile all of those and do "before and after" comparisons easily. To measure the time, we should probably try to compile each module at least a few times. (it seems that this is not currently possible with `tests/perf/compiler` and nofib only compiles the programs once AFAICS) Looking at the comments on the proposal from Moritz, most people would prefer to extend/improve nofib or `tests/perf/compiler` tests. So I guess the main question is - what would be better: - Extending nofib with modules that are compile only (i.e., not runnable) and focus on stressing the compiler? - Extending `tests/perf/compiler` with ability to run all the tests and do easy "before and after" comparisons? Personally, I'm slightly leaning towards `tests/perf/compiler` since this would allow sharing the same module as a test for `validate` and to be used for comparing the performance of the compiler before and after a change. What do you think? Thanks, Michal