[GHC] #490: object code blow up by minor source code change

[GHC]

#490: object code blow up by minor source code change
-----------------------+----------------------------------------------------
  Reporter:  c_maeder  |          Owner:  simonpj
      Type:  bug       |         Status:  new    
  Priority:  normal    |      Milestone:         
 Component:  Compiler  |        Version:  6.4.1  
  Severity:  normal    |     Resolution:  None   
  Keywords:            |             Os:  Unknown
Difficulty:  Unknown   |   Architecture:  Unknown
-----------------------+----------------------------------------------------
Comment (by simonpj):

 Just to let you know, I can reproduce this problem nicely (thank you for
 setting up the repro case). It turns out to be caused by the simplifier's
 inlining policy which goes if not exponential then something very like it.
 It's made dramatically worse by the fact that $$ and <+> are left-
 associative. If you change them to right-assoc the problem disappears I
 think.

 That's not an excuse -- the simplifier should not do this -- but it might
 be a useful workaround.

 Simon

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/490>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler