patch applied (ghc): Fix Trac #1969: perfomance bug in the specialiser

[Simon Peyton Jones]

Mon Apr 28 08:57:11 PDT 2008  simonpj at microsoft.com
  * Fix Trac #1969: perfomance bug in the specialiser
  
  The specialiser was using a rather brain-dead representation for
  UsageDetails, with much converting from lists to finite maps and
  back.  This patch does some significant refactoring.  It doesn't
  change the representation altogether, but it does eliminate the
  to-and-fro nonsense.
  
  It validates OK, but it's always possible that I have inadvertently
  lost specialisation somewhere, so keep an eye out for any run-time
  performance regressions.
  
  Oh, and Specialise is now warning-free too.
  

    M ./compiler/specialise/Specialise.lhs -108 +113

View patch online:
http://darcs.haskell.org/ghc/_darcs/patches/20080428155711-1287e-8f8a854ee28b8b9be06bfb742579580a8ee6b82d.gz