[darcs-devel] performance of darcs with ghc 6.6 vs 6.4?

Donald Bruce Stewart dons at cse.unsw.edu.au
Wed Oct 11 15:29:42 PDT 2006


mark:
> Following the Perl 6 project, I see reports that pugs is
> noticeably faster when compiled with GHC 6.6 vs. 6.4.
> 
> I was wondering if some of the slower operations of darcs might also
> be faster when compiled with a newer GHC or if the issues are primarily
> algorithmic, making this difference insignificant.

Part of the pugs speed up is due to the new Data.ByteString
implementation that comes with 6.6. Data.ByteString is significantly
faster under 6.6 than 6.4. There are two main reasons for this:
ForeignPtr is much better; and GHC is smarter with custom rewrite rules.

Although darcs doesn't use Data.ByteString, they share the same
ForeignPtr library underneath, and hopefully darcs will also benefit
from the various improvements made to ForeignPtr.

So I'd expect some improvement in the performance of FastPackedString.

-- Don




More information about the darcs-devel mailing list