[GHC] #9203: Perf regression in 7.8.2 relative to 7.6.3, possibly related to HashMap

[GHC]

#9203: Perf regression in 7.8.2 relative to 7.6.3, possibly related to HashMap
--------------------------------------------+------------------------------
        Reporter:  simonmar                 |            Owner:
            Type:  bug                      |           Status:  new
        Priority:  normal                   |        Milestone:  7.8.3
       Component:  Compiler                 |          Version:  7.8.2
      Resolution:                           |         Keywords:
Operating System:  Unknown/Multiple         |     Architecture:
 Type of failure:  Runtime performance bug  |  Unknown/Multiple
       Test Case:                           |       Difficulty:  Unknown
        Blocking:                           |       Blocked By:
                                            |  Related Tickets:
--------------------------------------------+------------------------------

Comment (by simonmar):

 Hang on, I'm just doing some more investigation in `TypeRep`, I think it
 might be in there after all.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9203#comment:3>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler