[GHC] #2289: Needless reboxing of values when returning from a tight loop

[GHC]

#2289: Needless reboxing of values when returning from a tight loop
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        Reporter:  dons              |                Owner:
            Type:  bug               |               Status:  new
        Priority:  lowest            |            Milestone:
       Component:  Compiler          |              Version:  6.8.2
      Resolution:                    |             Keywords:  boxing,
                                     |  loops, performance
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Runtime           |  Unknown/Multiple
  performance bug                    |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #2387,#1600       |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by simonpj):

 Yes, nested CPR would be great.  See [wiki:NestedCPR] for Joachim's
 writeup of his work on it; lots of stuff there.

 Re one-specialisation: `SpecConstr` is free to generate lots of
 specialisations. But the demand analyser does not make many copies of a
 function, one for each demand pattern.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/2289#comment:47>
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