cd testsuite/tests/perf; make | -----Original Message----- | From: ghc-devs [mailto:ghc-devs-bounces@haskell.org] On Behalf Of Richard | Eisenberg | Sent: 12 February 2016 19:04 | To: ghc-devs@haskell.org developers | Subject: quick performance measurements | | Hi devs, | | I have a few ideas for tweaks to improve compiler performance. (For example, | reversing the order of comparisons in a short-circuiting comparison | operation.) I don't have a particular test case with a profile that tells me | where the smoking gun is. But I'd like to try these easy tweaks just to see | if performance improves. | | My question: | Is there an easy way to run some command that will give me helpful feedback | on my performance tweak? | | Of course, I could push to a branch and have | https://na01.safelinks.protection.outlook.com/?url=perf.haskell.org&data=01%7 | c01%7csimonpj%40064d.mgd.microsoft.com%7cb2e1edc8a6f248a9066508d333df5623%7c7 | 2f988bf86f141af91ab2d7cd011db47%7c1&sdata=wU6DNmX%2bLF8sagU0B9yJAh4MKJ3yJc1CA | omIiSI%2fqvM%3d tell me. But that takes a long time. I could compile a few | files and examine the output manually. But that's a bit painful. Ideally, | there would be a way to run a portion of the testsuite and have the testsuite | tool aggregate performance characteristics and report. Or perhaps there's a | way to get cabal to aggregate performance characteristics, and I could just | try compiling a few libraries. Any ideas out there? | | Thanks! | Richard | _______________________________________________ | ghc-devs mailing list | ghc-devs@haskell.org | https://na01.safelinks.protection.outlook.com/?url=http%3a%2f%2fmail.haskell. | org%2fcgi-bin%2fmailman%2flistinfo%2fghc- | devs&data=01%7c01%7csimonpj%40064d.mgd.microsoft.com%7cb2e1edc8a6f248a9066508 | d333df5623%7c72f988bf86f141af91ab2d7cd011db47%7c1&sdata=JnjGw%2fk%2brdNGy9VNY | 0m1KA7Ojr2ubJO6PneeGVL4LmY%3d

Hi, Am Freitag, den 12.02.2016, 14:04 -0500 schrieb Richard Eisenberg:

Ideally, there would be a way to run a portion of the testsuite and have the testsuite tool aggregate performance characteristics and report.

if you run the test suite with $ VERBOSE=4  you get the detailed stats for every perf test, not only for the failing ones. This is what the gipeda runner does. You’d still have to manually compare them, though; no aggregation happening. Also, the compiler perf test cases usually check one specific extreme code path, so they are not a good measure of real world performance. nofib is better there, and has comparing integrated, but only checks those parts of the compiler that deal with idiomatic Haskell code from 10 or 20 years back. Maybe I should write a text that explains how to run gipeda locally on a bunch of commits on a local branch... but it’s only making the results more shiny, not more significant, than running nofib or the test suite manually. Greetings, Joachim -- Joachim “nomeata” Breitner   mail@joachim-breitner.de • https://www.joachim-breitner.de/   XMPP: nomeata@joachim-breitner.de • OpenPGP-Key: 0xF0FBF51F   Debian Developer: nomeata@debian.org