Re: [Haskell-cafe] mtlx has a nice design but is slow
GHC's goal is to be good enough at inlining and optimisation that you shouldn't take a performance hit for adding layers of abstraction. Sometimes it needs help (eg inlining pragmas). So as Don implies, it might be worth digging a bit to see where the performance hit comes from. Simon | -Original Message- | From: haskell-cafe-boun...@haskell.org [mailto:haskell-cafe- | boun...@haskell.org] On Behalf Of Don Stewart | Sent: 06 April 2011 18:19 | To: Sean Leather | Cc: Haskell Café List | Subject: Re: [Haskell-cafe] mtlx has a nice design but is slow | | Is the package missing some obvious inlining in the instances? | | On Wed, Apr 6, 2011 at 10:13 AM, Sean Leather wrote: | > I just refactored my type and transform system prototype (introduced in [1] | > but changed since then) from using mtlx [2] (type-indexed monad | transformers | > described in [3]) to mtl using RWST. mtlx allowed me to cleanly separate | the | > various monadic components in a convenient way. Unfortunately, I found it | to | > be too slow. The refactoring was an experiment to see how slow. I was | rather | > surprised: | > | > Running time of a compiled main with a list of tests: | > mtlx (7 transformers): 2 min 52 sec | > mtl (RWST): 0 min 13 sec | > | > It's frustrating to see such a huge performance gap for a better design. | > | > Regards, | > Sean | > | > [1] | > http://splonderzoek.blogspot.com/2011/03/draft-type-changing-program- | improvement.html | > [2] http://hackage.haskell.org/package/mtlx | > [3] http://www.ittc.ku.edu/~marks/cgi-bin/pubs/monadfactory.pdf | > | > | > ___ | > Haskell-Cafe mailing list | > Haskell-Cafe@haskell.org | > http://www.haskell.org/mailman/listinfo/haskell-cafe | > | > | | ___ | Haskell-Cafe mailing list | Haskell-Cafe@haskell.org | http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] mtlx has a nice design but is slow
Typically you'll want to inline any definitions of >>= and return in your classes and instances. Also, any non-recursive top level wrapper functions. On Wed, Apr 6, 2011 at 3:00 PM, Mark Snyder wrote: > I'm the author for mtlx, and admittedly I didn't do anything about > efficiency when I implemented it. Is there any initial place I ought to > look for tips on inlining? I'll start with the pragmas page > (http://www.haskell.org/ghc/docs/7.0.3/html/users_guide/pragmas.html) I > suppose. I'm happy for any suggestions--optimizing hasn't been one of my > focuses, so it's time for me to learn I suppose! > I did switch to newtype definitions in the most recent version (0.1.5), > which probably helped a lot compared to data definitions, but there are no > inline pragmas in use, so perhaps there are some good opportunities for > optimization. > ~Mark Snyder >> >>Is the package missing some obvious inlining in the instances? >> >>> I just refactored my type and transform system prototype (introduced in >>> [1] >>> but changed since then) from using mtlx [2] (type-indexed monad >>> transformers >>> described in [3]) to mtl using RWST. mtlx allowed me to cleanly separate >>> the >>> various monadic components in a convenient way. Unfortunately, I found it >>> to >>> be too slow. The refactoring was an experiment to see how slow. I was >>> rather >>> surprised: >>> >>> Running time of a compiled main with a list of tests: >>> ? mtlx (7 transformers): 2 min 52 sec >>> ? mtl (RWST): 0 min 13 sec >>> >>> It's frustrating to see such a huge performance gap for a better design. >>> >>> Regards, >>> Sean >>> > > > > > ___ > Haskell-Cafe mailing list > Haskell-Cafe@haskell.org > http://www.haskell.org/mailman/listinfo/haskell-cafe > > ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] mtlx has a nice design but is slow
I'm the author for mtlx, and admittedly I didn't do anything about efficiency when I implemented it. Is there any initial place I ought to look for tips on inlining? I'll start with the pragmas page (http://www.haskell.org/ghc/docs/7.0.3/html/users_guide/pragmas.html) I suppose. I'm happy for any suggestions--optimizing hasn't been one of my focuses, so it's time for me to learn I suppose! I did switch to newtype definitions in the most recent version (0.1.5), which probably helped a lot compared to data definitions, but there are no inline pragmas in use, so perhaps there are some good opportunities for optimization. ~Mark Snyder > >Is the package missing some obvious inlining in the instances? > >> I just refactored my type and transform system prototype (introduced in [1] >> but changed since then) from using mtlx [2] (type-indexed monad transformers >> described in [3]) to mtl using RWST. mtlx allowed me to cleanly separate the >> various monadic components in a convenient way. Unfortunately, I found it to >> be too slow. The refactoring was an experiment to see how slow. I was rather >> surprised: >> >> Running time of a compiled main with a list of tests: >> ? mtlx (7 transformers): 2 min 52 sec >> ? mtl (RWST): 0 min 13 sec >> >> It's frustrating to see such a huge performance gap for a better design. >> >> Regards, >> Sean >> ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] mtlx has a nice design but is slow
Is the package missing some obvious inlining in the instances? On Wed, Apr 6, 2011 at 10:13 AM, Sean Leather wrote: > I just refactored my type and transform system prototype (introduced in [1] > but changed since then) from using mtlx [2] (type-indexed monad transformers > described in [3]) to mtl using RWST. mtlx allowed me to cleanly separate the > various monadic components in a convenient way. Unfortunately, I found it to > be too slow. The refactoring was an experiment to see how slow. I was rather > surprised: > > Running time of a compiled main with a list of tests: > mtlx (7 transformers): 2 min 52 sec > mtl (RWST): 0 min 13 sec > > It's frustrating to see such a huge performance gap for a better design. > > Regards, > Sean > > [1] > http://splonderzoek.blogspot.com/2011/03/draft-type-changing-program-improvement.html > [2] http://hackage.haskell.org/package/mtlx > [3] http://www.ittc.ku.edu/~marks/cgi-bin/pubs/monadfactory.pdf > > > ___ > Haskell-Cafe mailing list > Haskell-Cafe@haskell.org > http://www.haskell.org/mailman/listinfo/haskell-cafe > > ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] mtlx has a nice design but is slow
I just refactored my type and transform system prototype (introduced in [1] but changed since then) from using mtlx [2] (type-indexed monad transformers described in [3]) to mtl using RWST. mtlx allowed me to cleanly separate the various monadic components in a convenient way. Unfortunately, I found it to be too slow. The refactoring was an experiment to see how slow. I was rather surprised: Running time of a compiled main with a list of tests: mtlx (7 transformers): 2 min 52 sec mtl (RWST): 0 min 13 sec It's frustrating to see such a huge performance gap for a better design. Regards, Sean [1] http://splonderzoek.blogspot.com/2011/03/draft-type-changing-program-improvement.html [2] http://hackage.haskell.org/package/mtlx [3] http://www.ittc.ku.edu/~marks/cgi-bin/pubs/monadfactory.pdf ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
