[GHC] #7944: GHC goes into an apparently infinite loop at -O2

[GHC]

#7944: GHC goes into an apparently infinite loop at -O2
-------------------------------------+-------------------------------------
        Reporter:  bos               |                Owner:  (none)
            Type:  bug               |               Status:  patch
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  7.9
      Resolution:                    |             Keywords:  SpecConstr
Operating System:  Unknown/Multiple  |         Architecture:  x86_64
 Type of failure:  Compile-time      |  (amd64)
  crash                              |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #5550 #8852       |  Differential Rev(s):  Phab:D3404
       Wiki Page:                    |
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Changes (by RyanGlScott):

 * cc: ezyang (added)
 * status:  new => patch
 * differential:   => Phab:D3404


Comment:

 Huh, the commit that fixed this turned out to be something quite different
 from what I was imagining. It's actually
 b8b3e30a6eedf9f213b8a718573c4827cfa230ba (Axe RecFlag on TyCons.) I don't
 know if this change directly fixes the issue or if it's just a happy
 coincidence (ezyang, any thoughts?), but either way, I've added a
 regression test in Phab:D3404.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7944#comment:14>
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