[Haskell-cafe] Benchmarks game updated to ghc 6.12.2
Ketil Malde ketil at malde.org writes: As for code size, the programs are heavily tuned for speed. iirc there was a community effort 2 or 3 years ago, but now ghc has changed enough that the compiler and runtime parameters seem to need re-tuning. Is it an idea to go back a few steps to more idiomatic code? Perhaps as a separate track? There's always room for 2 or 3 Haskell programs per task - not necessarily The Good, the Bad and the Ugly - but you'll already find the cliched example of a faster more convoluted Haskell program and a more concise but slower Haskell program. (Idiomatic code? Aren't there idioms for writing fast Haskell too?) I also worry a bit that source code optimization for a specific compiler makes it more difficult to take advantage of compiler optimization improvements. These are tiny tiny programs - when those compiler optimization improvements arrive re-write the programs to take advantage of them ;-) ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Benchmarks game updated to ghc 6.12.2
igouy2: Ketil Malde ketil at malde.org writes: As for code size, the programs are heavily tuned for speed. iirc there was a community effort 2 or 3 years ago, but now ghc has changed enough that the compiler and runtime parameters seem to need re-tuning. Even longer ago -- some of those 'optimized' programs date to 2005 if I recall. -- Don ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Benchmarks game updated to ghc 6.12.2
2010/04/30 Don Stewart d...@galois.com: Prior to the upgrade we weren't mostly beaten on speed, so I think a bit of tuning (ghc -server :) should help. What do you mean by that? I tried searching the flags page: http://www.haskell.org/ghc/docs/6.12.2/html/users_guide/flag-reference.html I couldn't find a server flag. -- Jason Dusek ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Benchmarks game updated to ghc 6.12.2
jason.dusek: 2010/04/30 Don Stewart d...@galois.com: Prior to the upgrade we weren't mostly beaten on speed, so I think a bit of tuning (ghc -server :) should help. What do you mean by that? I tried searching the flags page: http://www.haskell.org/ghc/docs/6.12.2/html/users_guide/flag-reference.html I couldn't find a server flag. Java has a server flag, sort of like defaulting to -H1G -N4 etc. -- Don ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Benchmarks game updated to ghc 6.12.2
ketil: Don Stewart d...@galois.com writes: http://shootout.alioth.debian.org/u64q/haskell.php Observations: Although we're mostly beaten on speed, and about the same on code size, we're using a lot less memory than Java. Prior to the upgrade we weren't mostly beaten on speed, so I think a bit of tuning (ghc -server :) should help. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Benchmarks game updated to ghc 6.12.2
Don Stewart d...@galois.com writes: http://shootout.alioth.debian.org/u64q/haskell.php Observations: Although we're mostly beaten on speed, and about the same on code size, we're using a lot less memory than Java. As for code size, the programs are heavily tuned for speed. Although it is nice to show that we can indeed be fast, Haskell's forte is being almost as fast while clear and compact. Is it an idea to go back a few steps to more idiomatic code? Perhaps as a separate track? I also worry a bit that source code optimization for a specific compiler makes it more difficult to take advantage of compiler optimization improvements. -k -- If I haven't seen further, it is by standing in the footprints of giants ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Benchmarks game updated to ghc 6.12.2
Ketil Malde ke...@malde.org writes: Is it an idea to go back a few steps to more idiomatic code? I had a whirl at the 'reverse complement' benchmark, where we're in the Java ballpark for performance and memory, but at twice the code size. My simple implmentation is down from seventy to about forty lines, perhaps thirty-five if I remove comments etc. The bad news is that it's about twice as slow, my benchmark takes about 0.45s vs 0.25 for the shootout entry. One interesting observation is that 'map' from Data.ByteString working directly on Word8 is actually *slower* than 'map' from Data.ByteString.Char8. Anyway - it occurs to me that this can fairly simply be sped up by parallelizing: chunk the input, complement chunks in parallel, and reverse. Any takers? -k -- If I haven't seen further, it is by standing in the footprints of giants ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Benchmarks game updated to ghc 6.12.2
On Thu, Apr 29, 2010 at 10:54:09AM +0200, Ketil Malde wrote: Anyway - it occurs to me that this can fairly simply be sped up by parallelizing: chunk the input, complement chunks in parallel, and reverse. Any takers? Do you mean, something like this? import Data.ByteString.Char8 as S import Data.ByteString.Lazy.Char8 as L import Data.ByteString.Lazy.Internal as LI map' :: (Char - Char) - L.ByteString - L.ByteString map' f = go where go LI.Empty= LI.Empty go (LI.Chunk x xs) = let fx = S.map f x fxs = go xs in fxs `par` LI.Chunk fx fxs -- Chunk is strict in fx. Cheers, -- Felipe. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Benchmarks game updated to ghc 6.12.2
Felipe Lessa felipe.le...@gmail.com writes: On Thu, Apr 29, 2010 at 10:54:09AM +0200, Ketil Malde wrote: Anyway - it occurs to me that this can fairly simply be sped up by parallelizing: chunk the input, complement chunks in parallel, and reverse. Any takers? Do you mean, something like this? Yes, that's exactly what I mean (you also need to reverse each chunk for this particular problem). Of course, it remains to see how well it performs in practice - it's not something I would expect to get right at the first attempt (I haven't used parallelism much so far). Several of the shootout benchmarks suffer from using only one CPU, so given Haskell/GHCs claim for easy concurrency, there should be some relatively low-hanging fruit there. -k -- If I haven't seen further, it is by standing in the footprints of giants ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Benchmarks game updated to ghc 6.12.2
On Thu, Apr 29, 2010 at 12:38 AM, Ketil Malde ke...@malde.org wrote: Don Stewart d...@galois.com writes: http://shootout.alioth.debian.org/u64q/haskell.php Observations: Although we're mostly beaten on speed, and about the same on code size, we're using a lot less memory than Java. As for code size, the programs are heavily tuned for speed. Although it is nice to show that we can indeed be fast, Haskell's forte is being almost as fast while clear and compact. Is it an idea to go back a few steps to more idiomatic code? Perhaps as a separate track? I also worry a bit that source code optimization for a specific compiler makes it more difficult to take advantage of compiler optimization improvements. I was thinking the same thing with regard to the code being idiomatic Haskell. Then I took a look at the top entry (in GCC C), which has special malloc/free functions to achieve cache alignment. Then I realized just how nice the current Haskell version is :) Jason ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Benchmarks game updated to ghc 6.12.2
The benchmarks game has been updated to use 6.12.2 Please dive in and help tweak/improve/spot any regressions. Esp. with respect to multicore flags/options/... - Forwarded message from Isaac Gouy - Subject: fyi benchmarks game updated to ghc 6.12.2 http://shootout.alioth.debian.org/u64q/haskell.php best wishes, Isaac - End forwarded message - ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
