[GHC] #8836: ghc 7.6.3 and 7.4.2 hang on -O2

[GHC]

#8836: ghc 7.6.3 and 7.4.2 hang on -O2
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        Reporter:  tsuraan                  |            Owner:
            Type:  bug                      |           Status:  closed
        Priority:  normal                   |        Milestone:
       Component:  Compiler                 |          Version:  7.6.3
      Resolution:  duplicate                |         Keywords:
Operating System:  Unknown/Multiple         |     Architecture:
 Type of failure:  GHC doesn't work at all  |  Unknown/Multiple
       Test Case:                           |       Difficulty:  Unknown
        Blocking:                           |       Blocked By:
                                            |  Related Tickets:
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Changes (by thoughtpolice):

 * status:  new => closed
 * resolution:   => duplicate


Comment:

 Right, then we know what's wrong. Unfortunately, there isn't really a good
 'fix' that's possible to backport to fix `SpecConstr` for 7.6 users - in
 the mean time, you'll have to get by with `-O1` or (`-O2 -fno-spec-
 constr`, I suppose). Alternatively, you can also try tuning the
 constructor specialisation threshold as noted in #7944.

 There won't be a 7.6.4 release, and as this is fixed in HEAD, I'm marking
 this as a duplicate.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8836#comment:5>
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