#9630: compile-time performance regression (probably due to Generics) -------------------------------------+------------------------------------- Reporter: hvr | Owner: dfeuer Type: bug | Status: new Priority: high | Milestone: 8.2.1 Component: Compiler | Version: 7.9 Resolution: | Keywords: deriving- | perf, Generics 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): #13059, #10818 | Wiki Page: | -------------------------------------+------------------------------------- Comment (by dfeuer): I think the original issue is fixed. To be extra clear, the original issue was that it was very slow to compile `Language.Haskell.Extension` from `Cabal`. I was able to reproduce this using Cabal at commit [https://github.com/haskell/cabal/commit/eaf2aae18603965ff668384b391fcaa14de1... eaf2aae18603965ff668384b391fcaa14de19823]. The problem there appeared in GHC commit b9e49d3e9580e13d89efd1f779cb76f610e0d6e0, which added 1024 specialization rules for said module. The problem is now gone. It looks to me as though ezyang's test case in comment:22 doesn't actually relate to the regression; I don't see it moving terribly much from 7.8 to 7.10 or from 7.10 to 8.2. It seems to be looking at other issues. I will try to see how those have shifted. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9630#comment:48 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler