Hi all, i have changed the compilation flags and the codes as you said. It seems to me that it worked, since the runtime of my test stabilized at 2002ns. Before, i got sometimes 4004ns. The bigger runtime part is now (as far as i can guess, see below why) the screen output. That brings me to two issues for performance tests in Haskell: 1. how can i do performance tests if the tests are small? In imperative languages, you cycle through 1000 times and divide the runtime by 1000. How can i do something similar in haskell? 2. How do i get haskell to do something _without_ printing anything on the screen? For now, i do something like main = do startt <- getCPUTime putStr $ (show testAIBD1) ++ ", " ++ (show testZins1) endt <- getCPUTime putStr $ "\tTook " ++ (show $ (endt - startt) `div` ((10^6) * 5)) ++ " ns\n" where testAIBD1 is a sum of 40 calculation results and also is testZins1. Another issue: with foreign C calls i have the problem to link automatically. i type something like
ghc --make Main.hs -fglasgow-exts -O2 -fliberate-case-threshold100 -funbox-strict-fields -fvia-C while having compiled the external C HAIBDUtil.c with HAIBDUtil.h to HAIBDUtil.o. As result, i get
Chasing modules from: Main.hs Compiling AIBD ( AIBD.hs, ./AIBD.o ) Compiling Main ( Main.hs, ./Main.o ) Linking ... AIBD.o(.text+0x11e0):ghc1052.hc: undefined reference to `caibd' shure, "caibd" is the called C procedure from AIBD. well then, i type
ghc Main.o AIBD.o HAIBDUtil.o -o HAIBD.exe
then everything is fine, and i get my executable. Now i wanted to profile, and added the options "-prof --auto-all" to the first ghc command. When trying to link, i get lot's of undefined references:
ghc Main.o AIBD.o HAIBDUtil.o -o HAIBD.exe
AIBD.o(.text+0x425):ghc1364.hc: undefined reference to `CC_LIST' AIBD.o(.text+0x430):ghc1364.hc: undefined reference to `CC_LIST' AIBD.o(.text+0x439):ghc1364.hc: undefined reference to `CC_ID' AIBD.o(.text+0x444):ghc1364.hc: undefined reference to `CC_ID' (...) AIBD.o(.text+0x5fc):ghc1364.hc: undefined reference to `CCCS' AIBD.o(.text+0x605):ghc1364.hc: undefined reference to `CCCS' AIBD.o(.text+0x626):ghc1364.hc: undefined reference to `PushCostCentre' (...) Obviously (see "PushCostCentre" as last misssing reference), something for profiling is missing. What is it? Regards, Andreas Schroeder |---------+-----------------------------------------> | | Andreas.Schroeder@gillardon.de| | | Gesendet von: | | | glasgow-haskell-users-bounces@| | | haskell.org | | | | | | | | | 16.10.2003 09:37 | | | | |---------+----------------------------------------->
-------------------------------------------------------------------------------------------------------------------| | | | An: glasgow-haskell-users@haskell.org | | Kopie: chak@cse.unsw.edu.au | | Thema: Re: GHC with MS .Net 2003 C compiler | -------------------------------------------------------------------------------------------------------------------|
Hi all, hi Manuel,
thanks for the help. Yes, i read the user docs for "earlier, faster,
thriftier, smaller ..." or a permutation of this,
but i do not _really_ remember from my university time what strict
functions are. Is by strict meant as in Formal OO that
a function is trict iff its result is _|_ iff any of its arguments is _|_ ?
I will try to use
data Genauigkeit = Absolut {wert, intervall :: !Double}
| Intervall !Double
is that what you meant? I will read the strictness flag documentation.
Thanks for the hints.
Regards,
Andreas Schroeder
|---------+----------------------------------------->
| | Manuel M T Chakravarty |
| |
-------------------------------------------------------------------------------------------------------------------| | | | An: Andreas.Schroeder@gillardon.de | | Kopie: glasgow-haskell-users@haskell.org | | Thema: Re: GHC with MS .Net 2003 C compiler |
-------------------------------------------------------------------------------------------------------------------| Andreas.Schroeder@gillardon.de wrote, Generally, did you look at http://haskell.org/ghc/docs/latest/html/users_guide/faster.html
module AIBD(aibd, rechneZins, rechneRate, rechneKapital) where import Foreign(unsafePerformIO)
type Funktion = Double -> Double
data Genauigkeit = Absolut {wert, intervall :: Double} | Intervall Double
See the paragraph under "Use strictness annotations" on the above web page on how to use strictness annotations to speed this data type up.
istOk :: Genauigkeit -> Double -> Double -> Bool istOk (Absolut w i) x _ = abs (x-w) <= i istOk (Intervall i) _ dx = abs dx <= i
sekantenVerfahren :: Funktion -> Genauigkeit -> Genauigkeit -> Int -> Double -> Double sekantenVerfahren f gx gy tiefe start = sekantenIter f tiefe gx gy x1 x2 y1 y2 where x1 = start x2 = start + start * 0.1 y1 = f x1 y2 = f x2 sekantenIter _ 0 _ _ _ x2 _ _ = x2 sekantenIter f tiefe gx gy x1 x2 y1 y2 = let x3 = x2 - y2 * (x2 - x1) / (y2 - y1) y3 = f x3 dy = y3 - y2 dx = x3 - x2 in if (istOk gx x3 dx) && (istOk gy y3 dy) then x3 else sekantenIter f (tiefe-1) gx gy x2 x3 y2 y3
Code like this may benefit from using the option "-O2" and possibly also "-fliberate-case-threshold100" http://haskell.org/ghc/docs/latest/html/users_guide/flag-reference.html#AEN5...
foreign import ccall "HAIBDUtil.h caibd" caibd :: Double -> Double -> Double -> Int -> IO Double
aibd:: Double -> Double -> Double -> Int -> Double aibd kapital zins rate jahre = unsafePerformIO (caibd kapital zins rate jahre) {- does the same than aibd:: Double -> Double -> Double -> Int -> Double aibd kapital _ _ 0 = kapital aibd kapital zins rate jahre = aibd (kapital + kapital * zins - rate) zins rate (jahre-1) -}
Two comments with -O2 -fliberate-case-threshold100 the Haskell version may be as fast as the C version. If not, better foreign import as a pure functions foreign import ccall "HAIBDUtil.h caibd" caibd :: Double -> Double -> Double -> Int -> Double and omit the unsafePerformIO. Cheers, Manuel _______________________________________________ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users _______________________________________________ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users