[Haskell-cafe] speed: ghc vs gcc

[Dan Doel]

---- Test.hs ----

import Prelude hiding (sum, enumFromTo)

import Data.List.Stream (sum, unfoldr)

enumFromTo m n = unfoldr f m
 where f k | k <= n    = Just (k,k+1)
           | otherwise = Nothing

main = print . sum $ enumFromTo 1 (10^9 :: Int)

---- snip ----

dolio at zeke % time ./Test                                                             
500000000500000000
./Test  3.12s user 0.03s system 80% cpu 3.922 total
dolio at zeke % time ./Test-sum0                                                        
500000000500000000
./Test-sum0  3.47s user 0.02s system 80% cpu 4.348 total
dolio at zeke % time ./Test-sum0                                                        
500000000500000000
./Test-sum0  3.60s user 0.02s system 90% cpu 4.009 total
dolio at zeke % time ./Test                                                             
500000000500000000
./Test  3.11s user 0.02s system 81% cpu 3.846 total

---- snip ----

"Test-sum0" is with the sum0 function

"Test" is the code at the top of this mail.

-fvia-c -optc-O3 didn't seem to make a big difference with either Haskell 
example, so they're both with the default backend.

Your C++ code runs slowly on my system (around 1 second), but that's because 
it uses 32-bit ints, I guess (switching to long int sped it up).

-- Dan