[GHC] #2465: View + Pattern Match not fused sufficiently

[GHC]

#2465: View + Pattern Match not fused sufficiently
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 Reporter:  ryani                         |          Owner:         
     Type:  compile-time performance bug  |         Status:  new    
 Priority:  low                           |      Milestone:  _|_    
Component:  Compiler                      |        Version:  6.8.2  
 Severity:  normal                        |     Resolution:         
 Keywords:                                |     Difficulty:  Unknown
 Testcase:                                |   Architecture:  x86    
       Os:  Windows                       |  
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Changes (by simonpj):

  * priority:  normal => low
  * milestone:  => _|_

Comment:

 Fusion of recursive functions is a very interesting and well-studied area.

 GHC offers so-called "short-cut deforestation" for lists. (Search for that
 string.)  If you write `dnaView` using `build` (to make it a good
 producer), and `consts'` using `foldr` (to make it a good consumer) you
 may get better results.

 Also worth a look is Coutts/Leschinskiy et al on stream fusion.

 But GHC isn't going to fuse recursive functions all by itself anytime
 soon.  So I'll refile this as low priority.

 Don't let this discourage you from suggesting other optimisation "misses"
 though.

 Simon

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/2465#comment:5>
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