[GHC] #14626: No need to enter a scrutinised value

[GHC]

#14626: No need to enter a scrutinised value
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        Reporter:  heisenbug         |                Owner:  heisenbug
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.2.2
      Resolution:                    |             Keywords:  performance
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #13861            |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by Simon Peyton Jones <simonpj@…>):

 In [changeset:"bd438b2d67ec8f5d8ac8472f13b3175b569951b9/ghc" bd438b2/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="bd438b2d67ec8f5d8ac8472f13b3175b569951b9"
 Get evaluated-ness right in the back end

 See Trac #14626, comment:4.  We want to maintain evaluted-ness
 info on Ids into the code generateor for two reasons
 (see Note [Preserve evaluated-ness in CorePrep] in CorePrep)

 - DataToTag magic
 - Potentially using it in the codegen (this is Gabor's
   current work)

 But it was all being done very inconsistently, and actually
 outright wrong -- the DataToTag magic hasn't been working for
 years.

 This patch tidies it all up, with Notes to match.
 }}}

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14626#comment:7>
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