#9669: Long compile time/high memory usage for modules with many deriving clauses -------------------------------------+------------------------------------- Reporter: snoyberg | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.3 Resolution: | Keywords: Operating System: Linux | Architecture: x86_64 (amd64) Type of failure: Compile- | Difficulty: Unknown time performance bug | Blocked By: Test Case: | Related Tickets: Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- Comment (by simonpj): Thanks. The code is indeed pretty big, with a "term size" of over 200,000. A module of a few hundred lines is more like 40,000. The simplifier is run many times over this code so it's perhaps not surprising that it takes most of the compile time. Still, I wonder if there is anything non-linear going on, tickled by the form of the boilerplate code. The occurrence analyser runs exacty as often as the simplifier, yet only uses 5% of the time. You could try adding `-auto-all` (or whatever the flag is) for `Simplify` to get more detailed cost centre information on the simplifier? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9669#comment:7 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler