[GHC] #8173: GHC uses nub

[GHC]

#8173: GHC uses nub
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        Reporter:  nh2               |            Owner:  leroux
            Type:  bug               |           Status:  new
        Priority:  normal            |        Milestone:
       Component:  Compiler          |          Version:  7.6.3
      Resolution:                    |         Keywords:
Operating System:  Unknown/Multiple  |     Architecture:  Unknown/Multiple
 Type of failure:  Compile-time      |       Difficulty:  Moderate (less
  performance bug                    |  than a day)
       Test Case:                    |       Blocked By:
        Blocking:                    |  Related Tickets:
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Comment (by leroux):

 nofib benchmark comparisons of HEAD vs HEAD with ordNub patch applied.
 (BuildFlavour=quick)

 https://gist.github.com/leroux/6725810#file-headvordnub-analysis-L2988.

 ----

 hvr has pointed out that having cases for `[]`, `[a]`, and `[a, b]` will
 most probably prevent the overhead from using Set for trivial calls.
 I'll post an updated benchmark later today with that implemented.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8173#comment:9>
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