[GHC] #8326: Place heap checks common in case alternatives before the case

[GHC]

#8326: Place heap checks common in case alternatives before the case
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        Reporter:  jstolarek         |                Owner:  (none)
            Type:  task              |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  7.7
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Runtime           |  Unknown/Multiple
  performance bug                    |            Test Case:
      Blocked By:                    |             Blocking:  8317
 Related Tickets:  #1498             |  Differential Rev(s):  Phab:D343
       Wiki Page:                    |
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Comment (by simonpj):

 What Michael says in comment:42 seems to be exactly what item (3) in the
 Description is all about.  If the hot path does not allocate, then adding
 an allocation check into the hot path will cost time, eve if it reduces
 binary size.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8326#comment:43>
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