#9320: Inlining regression/strangeness in 7.8 -------------------------------------+------------------------------------- Reporter: dolio | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.2 Resolution: | Keywords: Differential Revisions: | Operating System: Unknown/Multiple Architecture: | Type of failure: Runtime Unknown/Multiple | performance bug Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | -------------------------------------+------------------------------------- Comment (by simonpj): Are you certain that this ever worked, in any version of GHC? What's happening is that we see {{{ test0 = /\s. \n v. test @ Data.Vector.Unboxed.Base.MVector @ (GHC.ST.ST s) @ GHC.Types.Int ($dPrimMonad_s1Mw @ s) ... }}} We run over the program gathering up specialised cals to `test`, but this one is discarded again because the `/\s` means that the `s` type variable in the call isn't visible at top level. To fix this we need to make the specialiser a bit cleverer, so that it'll generate a RULE like {{{ RULE forall s (d:forall s. PrimMonad (ST s)). test @ MVector @ (ST s) @ Int (d @ s) = $stest s }}} with accompanying definition {{{ $stest = /\s. <body-of-test> @ MVector @ (ST s) @ Int ($dPrimMonad_s1Mw @ s) }}} GHC has never done this. It could do, but it's a new thing. Simon -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9320#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler