[GHC] #14295: tagToEnum# leads to some silly closures

[GHC]

#14295: tagToEnum# leads to some silly closures
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        Reporter:  dfeuer            |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:  8.4.1
       Component:  Compiler          |              Version:  8.2.1
      Resolution:                    |             Keywords:  datacon-tags
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Runtime           |  Unknown/Multiple
  performance bug                    |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by simonpj):

 > What makes it delicate?

 Just that `CorePrep` is trying to establish some tricky output invariants
 (about ANF) etc, and is ''not'' a simplification engine.  If there are
 zero knock-on transformations then that's fine, but that's a delicate
 situation all by itself.

 Anyway, I'm not opposed, just doubtful about the cost/benefit tradeoff.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14295#comment:13>
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