[GHC] #6122: INLINE pragma not obeyed

[GHC]

#6122: INLINE pragma not obeyed
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  Reporter:  augustss          |          Owner:                  
      Type:  bug               |         Status:  closed          
  Priority:  normal            |      Milestone:                  
 Component:  Compiler          |        Version:  7.4.1           
Resolution:  wontfix           |       Keywords:                  
        Os:  Unknown/Multiple  |   Architecture:  Unknown/Multiple
   Failure:  None/Unknown      |     Difficulty:  Unknown         
  Testcase:                    |      Blockedby:                  
  Blocking:                    |        Related:                  
-------------------------------+--------------------------------------------
Changes (by simonmar):

  * status:  new => closed
  * difficulty:  => Unknown
  * resolution:  => wontfix


Comment:

 GHC doesn't do this because it is difficult to ensure termination.  The
 optimiser doesn't do normal-order reduction, which would be guaranteed to
 terminate, it does something like bottom-up reduction which is unlikely to
 terminate because we'll just keep unfolding `count`.  Making the optimiser
 terminate iff evaluation of the expression would terminate is tricky, and
 would at the least be a delicate invariant.

 (I hadn't fully appreciated this until Simon PJ pointed it out to me)

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/6122#comment:3>
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