[GHC] #9630: compile-time performance regression (probably due to Generics)

[GHC]

#9630: compile-time performance regression (probably due to Generics)
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        Reporter:  hvr               |                Owner:  simonpj
            Type:  bug               |               Status:  patch
        Priority:  high              |            Milestone:  8.0.1
       Component:  Compiler          |              Version:  7.9
      Resolution:                    |             Keywords:  deriving-perf
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Compile-time      |  Unknown/Multiple
  performance bug                    |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #9583, #10293     |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by ezyang):

 Yes, comment:22 gives a standalone case of how making a type class only
 have one method improves time. I can try to characterize this further.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9630#comment:27>
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