[GHC] #10606: avoid redundant stores to the stack when examining already-tagged data

[GHC]

#10606: avoid redundant stores to the stack when examining already-tagged data
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        Reporter:  rwbarton          |                   Owner:
            Type:  feature request   |                  Status:  new
        Priority:  normal            |               Milestone:
       Component:  Compiler          |                 Version:  7.11
  (CodeGen)                          |                Keywords:
      Resolution:                    |            Architecture:
Operating System:  Unknown/Multiple  |  Unknown/Multiple
 Type of failure:  Runtime           |               Test Case:
  performance bug                    |                Blocking:
      Blocked By:                    |  Differential Revisions:
 Related Tickets:                    |
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Changes (by rwbarton):

 * failure:  None/Unknown => Runtime performance bug


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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10606#comment:1>
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