Hi John, I'm vaguely curious, and have next week off, so if you can provide the code, and directions for running in both variants and the test case, I'll take a look. Please email me at ndmitchell -AT- gmail.com though, as I loose this email address at 11pm tonight :-)
Thanks Neil > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf > Of Simon Peyton-Jones > Sent: 21 November 2008 10:34 am > To: John Lato > Cc: glasgow-haskell-users@haskell.org; Don Stewart > Subject: RE: cross module optimization issues > > | This project is based on Oleg's Iteratee code; I started using his > | IterateeM.hs and Enumerator.hs files and added my own stuff to > | Enumerator.hs (thanks Oleg, great work as always). When I started > | cleaning up by moving my functions from Enumerator.hs to > MyEnum.hs, my > | minimal test case increased from 19s to 43s. > | > | I've found two factors that contributed. When I was cleaning up, I > | also removed a bunch of unused functions from IterateeM.hs (some of > | the test functions and functions specific to his running example of > | HTTP encoding). When I added those functions back in, and added > | INLINE pragmas to the exported functions in MyEnum.hs, I got the > | performance back. > | > | In general I hadn't added export lists to the modules yet, so all > | functions should have been exported. > > I'm totally snowed under with backlog from my recent absence, > so I can't look at this myself, but if anyone else wants to > I'd be happy to support with advice and suggestions. > > In general, having an explicit export list is good for > performance. I typed an extra section in the GHC performance > resource http://haskell.org/haskellwiki/Performance/GHC to > explain why. In general that page is where we should > document user advice for performance in GHC. > > I can't explain why *adding* unused functions would change > performance though! > > Simon > > > _______________________________________________ > Glasgow-haskell-users mailing list > Glasgow-haskell-users@haskell.org > http://www.haskell.org/mailman/listinfo/glasgow-haskell-users > > ============================================================================== Please access the attached hyperlink for an important electronic communications disclaimer: http://www.credit-suisse.com/legal/en/disclaimer_email_ib.html ============================================================================== _______________________________________________ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
