[GHC] #14948: A program which benefits from a late specialisation pass

[GHC]

#14948: A program which benefits from a  late specialisation pass
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        Reporter:  mpickering        |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.2.2
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by simonpj):

 The odd thing is that this function still exists
 {{{
 > $s$fGHasTypeskaK1_$cgtypes1
 >   = \ @ f_a5xv $dApplicative_a5xx eta_B2 eta1_B1 ->
 }}}
 It has a dictionary argument so it'd ususally have been specialised
 earlier.   Looking at it, it could originally have been a function of type
 {{{
 foo :: forall a. C a => foralll b. D b => blah
 }}}
 Now, I think the specialiser might specialise only one "layer" of a
 function like that at a time.  And ''that'' might be fixable, if that's
 the problem.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14948#comment:3>
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