[GHC] #3116: missed opportunity for call-pattern specialisation

[GHC]

#3116: missed opportunity for call-pattern specialisation
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    Reporter:  duncan                    |        Owner:                  
        Type:  run-time performance bug  |       Status:  new             
    Priority:  normal                    |    Milestone:                  
   Component:  Compiler                  |      Version:  6.10.1          
    Severity:  normal                    |   Resolution:                  
    Keywords:                            |   Difficulty:  Unknown         
    Testcase:                            |           Os:  Unknown/Multiple
Architecture:  Unknown/Multiple          |  
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Comment (by simonpj):

 Oh, now I see, thanks.  But I have no clue how to implement it!  Just
 because 'f' has a profitable call pattern `(f (x:xs))` does NOT mean that
 `f` starts with case analysis on its first argument.  Or to put it another
 more precise way, what do you propose to replace Section 3.2 of
 [http://research.microsoft.com/en-us/um/people/simonpj/papers/spec-
 constr/index.htm the paper] with?

 I think you may be misled by a special case.

 Simon

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/3116#comment:5>
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