Here is a quick fix for the Random Numbers category. Looks like a
classic space-leak, again on the arithmetic operations. Speeds up
results for me about 6X and brings memory usage down out of the
stratosphere.
w/o strictness:
~/shootout$ time random 900000 +RTS -K32000000
75.544410151
real 0m0.756s
user 0m0.670s
sys 0m0.050s
w/ strictness:
~/shootout$ time random 900000 # <-- don't need massive heap
75.544410151
real 0m0.139s
user 0m0.100s
sys 0m0.010s
--
Robert
[EMAIL PROTECTED]
--- random.ghc 2004-10-07 08:51:20.000000000 -0400
+++ random.hs 2004-10-07 08:52:27.000000000 -0400
@@ -12,7 +12,9 @@
randloop :: Int -> Int -> Double -> Double -> Double
randloop 0 seed r max = r
-randloop n seed r max = randloop (n-1) newseed newrand max
+randloop n seed r max
+ | n `seq` seed `seq` r `seq` False = undefined
+ | otherwise = randloop (n-1) newseed newrand max
where normalize x max = (fromIntegral x) * (max / imd)
newseed = (seed * ia + ic) `mod` im
newrand = normalize newseed max
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