[GHC] #11792: Optimised unsafe FFI call can get wrong argument

[GHC]

#11792: Optimised unsafe FFI call can get wrong argument
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        Reporter:  Szunti            |                Owner:
            Type:  bug               |               Status:  new
        Priority:  high              |            Milestone:
       Component:  Compiler          |              Version:  7.10.3
      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):  Phab:D2263
       Wiki Page:                    |
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Comment (by osa1):

 I added a comment to the Phab ticket. I think we should fix the code gen
 so that if a register is written at some point A and read at point B, it
 should be kept alive no matter what.

 It'd be great if we could write some unit tests about that, but that needs
 a lot of infrastructure work...

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11792#comment:10>
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