<div dir="ltr">Hi Johannes,<div><br></div><div>see also this wiki page: <a href="https://ghc.haskell.org/trac/ghc/wiki/Performance/Runtime">https://ghc.haskell.org/trac/ghc/wiki/Performance/Runtime</a>.<div><br></div><div>It mentions the  `gcd` regression that you found (and has some analysis), but not the others (`tak` and `exp3_8`). Maybe you could start with updating that page.</div><div class="gmail_extra"><br></div><div class="gmail_extra">Thomas</div><div class="gmail_extra"><br><div class="gmail_quote">On Thu, Jan 7, 2016 at 9:55 AM, Simon Peyton Jones <span dir="ltr"><<a href="mailto:simonpj@microsoft.com" target="_blank">simonpj@microsoft.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">





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<p class="MsoNormal"><span style="font-family:"Calibri",sans-serif">Yes we’d love help with investigating, characterising, and fixing performance bugs.<u></u><u></u></span></p>
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<p class="MsoNormal"><span style="font-family:"Calibri",sans-serif">Simon<u></u><u></u></span></p>
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<p class="MsoNormal"><b><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif">From:</span></b><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif"> Haskell-Cafe [mailto:<a href="mailto:haskell-cafe-bounces@haskell.org" target="_blank">haskell-cafe-bounces@haskell.org</a>]
<b>On Behalf Of </b>Thomas Miedema<br>
<b>Sent:</b> 07 January 2016 00:52<br>
<b>To:</b> Johannes Waldmann <<a href="mailto:johannes.waldmann@htwk-leipzig.de" target="_blank">johannes.waldmann@htwk-leipzig.de</a>><br>
<b>Cc:</b> Joachim Breitner <<a href="mailto:mail@joachim-breitner.de" target="_blank">mail@joachim-breitner.de</a>>; Haskell cafe <<a href="mailto:haskell-cafe@haskell.org" target="_blank">haskell-cafe@haskell.org</a>><br>
<b>Subject:</b> Re: [Haskell-cafe] long-range performance comparisons (GHC over the years)<u></u><u></u></span></p>
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I recently noticed a performance problem <u></u><u></u></p>
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...<u></u><u></u></p>
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What worries me is that such a regression<br>
had been sitting there for over a year<u></u><u></u></p>
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There are 215 open <u><span style="color:#1155cc"><a href="https://ghc.haskell.org/trac/ghc/query?status=!closed&failure=Runtime+performance+bug&order=id" target="_blank">runtime performance</a></span></u> tickets (out of a total of 1655 open tickets, that
 makes 13%).<u></u><u></u></p>
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Compared to say new typesystem features, they don't get much attention. Only a few were <a href="https://ghc.haskell.org/trac/ghc/query?failure=Runtime+performance+bug&resolution=fixed&milestone=8.0.1&milestone=7.10.3&milestone=7.10.2" target="_blank">fixed</a> this
 year, most of them by Joachim Breitner (the new <a href="https://ghc.haskell.org/trac/ghc/wiki/CodeOwners#CurrentOwners" target="_blank">performance tsar</a>?). He also created <a href="https://na01.safelinks.protection.outlook.com/?url=https%3a%2f%2fperf.haskell.org%2fghc%2f&data=01%7c01%7csimonpj%40064d.mgd.microsoft.com%7cc3af688d2c234b3c19b608d316fcb626%7c72f988bf86f141af91ab2d7cd011db47%7c1&sdata=Ik7nCUHxNalCIxrv9E8dq2od9ed%2bbbLXJ%2fJJyHLCIhQ%3d" target="_blank">https://perf.haskell.org/ghc</a>.<u></u><u></u></p>
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In case you want to help out, start here: <a href="https://ghc.haskell.org/trac/ghc/wiki/Newcomers" target="_blank">
https://ghc.haskell.org/trac/ghc/wiki/Newcomers</a>.<u></u><u></u></p>
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