[GHC] #8852: 7.8.1 uses a lot of memory when compiling attoparsec programs using <|>

[GHC]

#8852: 7.8.1 uses a lot of memory when compiling attoparsec programs using <|>
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              Reporter:  joelteon    |            Owner:
                  Type:  bug         |           Status:  new
              Priority:  normal      |        Milestone:
             Component:  Compiler    |          Version:  7.8.1-rc2
            Resolution:              |         Keywords:
      Operating System:              |     Architecture:  Unknown/Multiple
  Unknown/Multiple                   |       Difficulty:  Unknown
       Type of failure:  Compile-    |       Blocked By:
  time performance bug               |  Related Tickets:
             Test Case:              |
              Blocking:              |
Differential Revisions:              |
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Comment (by simonpj):

 I made a little progress here.

 First, `SpecConstr` is not generating lots of code!  In fact it is doing
 no specialisation whatsoever.   BUT it is nevertheless taking a very long
 time to do, well, nothing.

 So something is afoot.

 Simon

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8852#comment:4>
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