Oops! Guess I'm going to have to refine my searching techniques. Thanks, Simon. Michael
--- On Fri, 5/27/11, Simon Marlow <[email protected]> wrote: From: Simon Marlow <[email protected]> Subject: Re: Parallel compilation and execution? To: "michael rice" <[email protected]> Cc: "David Virebayre" <[email protected]>, "Daniel Fischer" <[email protected]>, [email protected] Date: Friday, May 27, 2011, 7:08 AM On 26/05/2011 14:32, michael rice wrote: > Fair question. I copied the parallel version from: > > <http://www.haskell.org/ghc/docs/6.6/html/users_guide/lang-parallel.html> > http://www.haskell.org/ghc/docs/6.6/html/users_guide/lang-parallel.html That is the User Guide for GHC 6.6, incidentally. If you're using a later version of GHC (highly recommended especially for parallel stuff), then you should look at the docs for your version. Cheers, Simon > > <http://www.haskell.org/ghc/docs/6.6/html/users_guide/lang-parallel.html>but > pulled the non-parallel version from a text. > > Michael > > > --- On *Thu, 5/26/11, David Virebayre /<[email protected]>/* wrote: > > > From: David Virebayre <[email protected]> > Subject: Re: [Haskell-cafe] Parallel compilation and execution? > To: "michael rice" <[email protected]> > Cc: [email protected], "Daniel Fischer" > <[email protected]> > Date: Thursday, May 26, 2011, 8:56 AM > > > > 2011/5/26 michael rice <[email protected] > </mc/[email protected]>> > > Thank, Daniel > > Multiple threads are in evidence in my system monitor, but I > wonder why I'm getting two different answers, one twice the > other. The first is the parallel solution and the second is the non. > > > Why do you add n1+n2+1 in the parallel program, but only n1+n2 in > the non-parallel one ? > > > Michael > > =========== > > {- > import Control.Parallel > > nfib :: Int -> Int > nfib n | n <= 1 = 1 > | otherwise = par n1 (pseq n2 (n1 + n2 + 1)) > where n1 = nfib (n-1) > n2 = nfib (n-2) > -} > > nfib :: Int -> Int > nfib n | n <= 1 = 1 > | otherwise = nfib (n-1) + nfib (n-2) > > main = do putStrLn $ show $ nfib 39 > > ============= > > [michael@hostname ~]$ ghc --make -threaded nfib.hs > [1 of 1] Compiling Main ( nfib.hs, nfib.o ) > Linking nfib ... > [michael@hostname ~]$ ./nfib +RTS -N3 > 204668309 > [michael@hostname ~]$ ghc --make nfib.hs > [1 of 1] Compiling Main ( nfib.hs, nfib.o ) > Linking nfib ... > [michael@hostname ~]$ ./nfib > 102334155 > [michael@hostname ~]$ > > > > > _______________________________________________ > Haskell-Cafe mailing list > [email protected] > http://www.haskell.org/mailman/listinfo/haskell-cafe
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