#12367: Commit adding instances to GHC.Generics regression compiler performance -------------------------------------+------------------------------------- Reporter: bgamari | Owner: bgamari Type: bug | Status: new Priority: normal | Milestone: 8.0.2 Component: Compiler | Version: 8.0.1 Resolution: | Keywords: Generics 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 bgamari): So it appears that something is indeed calling for the `V1` dictionary and is therefore forcing the load of the `GHC.Generics` interface file, {{{ ... end stage interact with inerts } runStage top-level reactions { workitem = [W] $dFoldable_a2pp :: Foldable [] (CDictCan) doTopReact [W] $dFoldable_a2pp :: Foldable [] (CDictCan) matchClassInst pred = Foldable [] Starting fork { Dict fun $fFoldable[] ... } ending fork Dict fun $fFoldable[] Starting fork { Dict fun $fFoldableV1 Starting fork { Declaration for $fFoldableV1 Loading decl for $fFoldableV1 updating EPS_ Need decl for V1 Considering whether to load GHC.Generics {- SYSTEM -} Reading interface for GHC.Generics; reason: Need decl for V1 ... }}} Now to work out what. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12367#comment:12 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler