[GHC] #11666: Severe performance degradation in GHC 8.0.1 compared to GHC 7.10.x

[GHC]

#11666: Severe performance degradation in GHC 8.0.1 compared to GHC 7.10.x
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        Reporter:  mrkkrp            |                Owner:
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.0.1-rc2
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by simonpj):

 Sounds bad.

 The more you can help us by digging into exactly what is taking longer,
 the easier it'll be to help.  A 4.5x slowdown ought to be very easy to
 zero in on.

 Thanks!

 Simon

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11666#comment:2>
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