#14790: eqTypeRep does not inline -------------------------------------+------------------------------------- Reporter: dfeuer | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: 8.6.1 Component: Compiler | Version: 8.4.1-alpha2 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Runtime | Unknown/Multiple performance bug | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by dfeuer): mpickering, I get a bunch of things that look like this: {{{#!hs Considering inlining: eqTypeRep arg infos [TrivArg, TrivArg] interesting continuation CaseCtxt some_benefit True is exp: True is work-free: True guidance IF_ARGS [52 128] 210 0 discounted size = 180 ANSWER = NO }}} The continuation, some_benefit, and work-free lines all look good. I don't know how to read the guidance line. Has GHC allowed `eqTypeRep` to get too large to inline in most cases? If its decisions seem reasonable to you and other experienced folks, perhaps we should do something like {{{#!hs typeRepsSame :: forall k1 k2 (a :: k1) (b :: k2). TypeRep a -> TypeRep b -> Bool typeRepsSame a b = typeRepFingerprint a == typeRepFingerprint b eqTypeRep :: forall k1 k2 (a :: k1) (b :: k2). TypeRep a -> TypeRep b -> Maybe (a :~~: b) eqTypeRep a b | typeRepsSame a b = Just (unsafeCoerce# HRefl) | otherwise = Nothing {-# INLINE eqTypeRep #-} }}} inlining a very thin wrapper, but I was surprised enough by the choice that I figured it might point to a more general inlining heuristic problem. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14790#comment:6 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler