[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:  merge
        Priority:  normal            |            Milestone:  7.10.4
       Component:  Compiler          |              Version:  8.0.2
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Incorrect result  |  Unknown/Multiple
  at runtime                         |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by rwbarton):

 Thanks. I confirmed that the bug was present in HEAD as of Feb 1 but is
 not present any more.

 Something rather curious is that the bug cannot be reproduced when there
 are `.hi` and `.o` files present from a previous compilation with the same
 version of ghc, even when passing `-fforce-recomp`.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13429#comment:4>
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