[GHC] #10218: GHC creates incorrect code which throws <<loop>>

[GHC]

#10218: GHC creates incorrect code which throws <<loop>>
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        Reporter:  yongqli           |                   Owner:
            Type:  bug               |                  Status:  new
        Priority:  normal            |               Milestone:
       Component:  Compiler          |                 Version:  7.10.1
      Resolution:                    |                Keywords:
Operating System:  Unknown/Multiple  |            Architecture:
 Type of failure:  None/Unknown      |  Unknown/Multiple
      Blocked By:                    |               Test Case:  yes
 Related Tickets:                    |                Blocking:
                                     |  Differential Revisions:
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Comment (by simonpj):

 OK good.  Can you also try `-fno-cse`.   I guess that too will fix it.

 I would still ''really'' like to know how the incorrect demand info leads
 to a loop.  I still don't understand that.  I wonder if adding some
 `trace` calls might help show what is going on, without making the bug
 disappear?

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10218#comment:10>
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