More DPH

[Austin Seipp]

Hi,

I've been playing with DPH more; this time I've taken the Parallel
Strategies binary-trees benchmark and converted it to use DPH.

The results are here:

http://haskell.org/haskellwiki/Shootout/Parallel/BinaryTreesDPH

I haven't yet got anybody to test it on a 4/8 core machine, but on my
core2duo it performs reasonably well, although as you can see from the
test results, parallel strategies win every time (although some not by
very much.)

Is there any way to improve this code? I've noted at the bottom
something that might be a potential bottleneck, or does U.toList fuse
to make it as fast as possible?

Austin

P.S. I'm thinking of perhaps spending a few days and parallelising
some of the other benchmarks; I'll keep people updated if they want to
hear about it.