[GHC] #15155: How untagged pointers sneak into banged fields

[GHC]

#15155: How untagged pointers sneak into banged fields
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        Reporter:  heisenbug         |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:  8.6.1
       Component:  Compiler          |              Version:  8.4.2
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:  14677
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by simonpj):

 I'm lost in a maze of twisty passages.  We have

 * #14677 Code generator does not correctly tag a pointer.  I'm not sure if
 this is a serious bug, or just the loss of a potential optimisation.  (I
 think the latter.)

 * #14626 No need to enter a scrutinised value.  Apparently blocked on
 #14677

 * #14373 Introduce PTR-tagging for big constructor families.   This has
 Phab:D4267.  I think it may be blocked (in some way) on #15155.

 * #15155 (this ticket).

 I'm not sure how these tickets inter-relate beyond the blocking notes I've
 put here.  Which is most urgent?  Gabor, are you actively working on any
 of them?

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15155#comment:1>
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