[GHC] #8774: Transitivity of Auto-Specialization

[GHC]

#8774: Transitivity of Auto-Specialization
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        Reporter:  crockeea          |                Owner:
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  7.6.3
      Resolution:                    |             Keywords:  Inlining
Operating System:  Linux             |         Architecture:
 Type of failure:  Compile-time      |  Unknown/Multiple
  performance bug                    |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #5928, #8668,     |  Differential Rev(s):
  #8099                              |
       Wiki Page:                    |
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Comment (by erikd):

 Even with ghc 7.6, this seems to specialize correctly:

 {{{
 cabal exec -- ghc -fforce-recomp -ddump-simpl -dsuppress-idinfo main.hs
 2>&1 | grep 'Foo a'
 ...
     @ (Foo.Qux GHC.Types.Int)
     @ (Foo.Foo (Foo.Qux GHC.Types.Int))
     (Foo.$WBar @ (Foo.Qux GHC.Types.Int))
 ...
 }}}

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8774#comment:10>
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