#13395: 3x slowdown on GHC HEAD with file containing lots of overloaded string literals -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: (none) Type: bug | Status: closed Priority: high | Milestone: 8.2.1 Component: Compiler | Version: 8.1 Resolution: invalid | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple performance bug | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by RyanGlScott): * status: new => closed * resolution: => invalid Comment: Ugh, it turns out this was caused by me using a GHC HEAD that was built with the `quick` flavor instead of the `perf` flavor. I had thought that the only difference between the two was that the latter built Haddocks and other non-essentials—that couldn't have been more wrong! After rebuilding GHC HEAD with `perf`, I get this time: {{{ $ /usr/bin/time ~/Software/ghc4/inplace/bin/ghc-stage2 -fforce-recomp TextXmlHtmlHTMLMeta.hs [1 of 1] Compiling Text.XmlHtml.HTML.Meta ( TextXmlHtmlHTMLMeta.hs, TextXmlHtmlHTMLMeta.o ) 3.08user 0.07system 0:03.17elapsed 99%CPU (0avgtext+0avgdata 196820maxresident)k 0inputs+21464outputs (0major+41873minor)pagefaults 0swaps }}} Which is even //better// than 8.0.2! So this tale had a happy ending after all. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13395#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler