#9630: compile-time performance regression (probably due to Generics) -------------------------------------+------------------------------------- Reporter: hvr | Owner: simonpj Type: bug | Status: patch Priority: high | Milestone: 8.0.1 Component: Compiler | Version: 7.9 Resolution: | Keywords: deriving-perf Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple performance bug | Test Case: Blocked By: | Blocking: Related Tickets: #9583, #10293 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by simonpj): Thank you for helping to characterise this. More please! Eg is it the type checker, or all the way down the pipeline? Do terms get big? Why does putting Binary's classes in the file help? Why does removing `not- used` help. One possible reason: see [http://research.microsoft.com/en- us/um/people/simonpj/papers/variant-f/index.htm Scrap your type applications] Section 2.3. Generics, I suspect, uses lots of nested types! -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9630#comment:25 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler