[GHC] #6000: Performance of Fibonnaci compare to Python

[GHC]

#6000: Performance of Fibonnaci compare to Python
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 Reporter:  guest                    |          Owner:                     
     Type:  bug                      |         Status:  new                
 Priority:  normal                   |      Component:  Compiler           
  Version:  7.4.1                    |       Keywords:  python, performance
       Os:  Linux                    |   Architecture:  x86_64 (amd64)     
  Failure:  Runtime performance bug  |       Testcase:                     
Blockedby:                           |       Blocking:                     
  Related:                           |  
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 There's a 4 second, unjustified, difference in performance between the
 following Python fibonacci implementation and it's equivalent Haskell
 implementation (though the output core seems to be just fine!).

 -----PYTHON------
 def fib(n):
     one = 0
     two = 1
     for i in range(0,n):
         temp = two
         two = one + two
         one = temp
     return one

 if __name__ == "__main__":
     print fib(1000000);

 ----HASKELL-------
 {-# LANGUAGE BangPatterns #-}

 fib :: Int -> Integer
 fib 0 = 0
 fib 1 = 1
 fib n = fib' 0 1 2 where
     fib' _ y n' | n' > n = y
     fib' !x !y !n' = fib' y (x+y) (n'+1)

 main = fib 1000000 `seq` return ()

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/6000>
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