On Fri, May 04, 2007 at 09:02:03PM +0100, Neil Mitchell wrote: > Hi Adrian > > >The GHC users guide says overloading "is death to performance if > >left to linger in an inner loop" and one thing I noticed while > >playing about with the AVL lib was that using a HOF and passing > >the (overloaded) compare function as an explicit argument at the > >start seemed to give noticable a performance boost (compared with > >dictionary passing presumably). > > > >I'm not sure why that should be, but has anyone else noticed this? > > A HOF is one box, the Ord dictionary is an 8-box tuple containing HOF > boxes. When you invoke compare out of Ord, you are taking something > out of the tuple, whereas when you use the HOF its directly there. > > This is also the reason you get a performance decrease moving from a > 1-element class to a 2-element class.
What ever happened to OccurAnal? Stefan _______________________________________________ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
