[GHC] #15652: SerializedCompact has a [(Ptr a, Word)] instead of a custom datatype

[GHC]

#15652: SerializedCompact has a [(Ptr a, Word)] instead of a custom datatype
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        Reporter:  chessai           |                Owner:  ezyang
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:  8.8.1
       Component:                    |              Version:  8.4.3
  libraries/compact                  |             Keywords:  ghc-compact,
      Resolution:                    |  compact regions
Operating System:  Unknown/Multiple  |         Architecture:  aarch64
 Type of failure:  Runtime           |            Test Case:
  performance bug                    |
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by bgamari):

 I don't think there's any deep reason for this; it was likely just the
 most convenient choice at the time the code was written. Ultimately it
 seems unlikely that there will typically be enough blocks that unpacking
 will have a significant change in performance characteristics. Is there a
 particular motivation for wanting unpacking here?

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15652#comment:1>
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