[GHC] #13429: Optimizer produces Core with an infinite <<loop>>

[GHC]

#13429: Optimizer produces Core with an infinite <<loop>>
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        Reporter:  lehins            |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  highest           |            Milestone:  8.2.1
       Component:  Compiler          |              Version:  8.0.2
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  Runtime crash     |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #13750            |  Differential Rev(s):
       Wiki Page:                    |
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Changes (by simonpj):

 * priority:  high => highest
 * milestone:  7.10.4 => 8.2.1


Comment:

 This is a bad bug, and the `FingerTree` example is still happening in
 HEAD, so I assume also in 8.2.  (Previously it was only happening in 8.0.)
 I know what is going on but have been struggling to find time to fix it.
 Hopefully this week.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13429#comment:23>
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