[GHC] #14594: 2 modules / 2500LOC takes nearly 3 minutes to build

[GHC]

#14594: 2 modules / 2500LOC takes nearly 3 minutes to build
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        Reporter:  schyler           |                Owner:  dfeuer
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.0.2
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Compile-time      |  Unknown/Multiple
  performance bug                    |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by dfeuer):

 I see also that there's a fair bit of type gunk going on. The signature of
 `gfoldl` means that the combining function will be applied at O(n)
 different types, each a bit bigger than the last. Some other methods are
 similar. I don't know if this has any performance impact in the optimizer,
 but it might.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14594#comment:9>
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