#10818: GHC 7.10.2 takes much longer to compile some packages -------------------------------------+------------------------------------- Reporter: kazu-yamamoto | Owner: (none) Type: bug | Status: new Priority: high | Milestone: Component: Compiler | Version: 7.10.2 Resolution: | 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: | -------------------------------------+------------------------------------- Comment (by simonpj): I'm still puzzled by the ''quadrupling'' in compile time describe in the Description. Is that reproducible. Incrasing from 1.8s to 2.6s seems much less dramatic. Bisection is great! I would not have suspected that patch. Inspecting it, I think that perhaps dfuns are specialised after the patch but not before. Try `-dshow-passes` before and after to show code size; and `-ddump-rules` to show what specialision rules have been created (at least for top level things). Then worth checking that the extra specialisations make sense. (I'm assuming that this program does not actually say `-fspecialise- aggressively`? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10818#comment:19 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler