[GHC] #683: RULES for recursive functions don't work properly

[GHC]

#683: RULES for recursive functions don't work properly
----------------------+-----------------------------------------------------
 Reporter:  simonpj   |          Owner:  simonpj
     Type:  bug       |         Status:  closed 
 Priority:  low       |      Milestone:  _|_    
Component:  Compiler  |        Version:  6.4.1  
 Severity:  normal    |     Resolution:  fixed  
 Keywords:            |     Difficulty:  Unknown
 Testcase:            |   Architecture:  Unknown
       Os:  Unknown   |  
----------------------+-----------------------------------------------------
Changes (by simonpj):

  * status:  new => closed
  * resolution:  => fixed

Comment:

 The HEAD contains a much better treatment of recursion involving rewrite
 rules; see `Note [Loop breaking and RULES]` in `OccAnal`.

 I just checked that `mapM_ action [n..m]` fuses nicely (it does), and
 Roman's example above has the inlining for `bar`.

 So this one seems to be done.  As is often the case with performance bugs,
 we don't have a good way to add a regression test.  So I'm just closing
 it.

 Simon

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/683#comment:9>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler