gistfile1.hs

module Main where

import Data.Array.Accelerate as A
import Data.Array.Accelerate.Interpreter as I
import Data.Array.Accelerate.CUDA as C
import Prelude as P

type EFloat = (Float, Float) -- Represents a real number with a value and error

fromFloat :: Float -> EFloat
fromFloat x = (x, 0)

toFloat :: EFloat -> Float
toFloat (val, err) = val + err

add :: Exp EFloat -> Exp EFloat -> Exp EFloat
add = lift2 f
	where
		f :: (Exp Float, Exp Float) -> (Exp Float, Exp Float) -> (Exp Float, Exp Float)
		f (aval, aerr) (bval, berr) = (val, err)
			where
				val = aval + bval
				err = aval - (val - δ) + (bval - δ) + aerr + berr
				δ = val - aval

esum x = fold1 add x

main = do
	let x = use $ fromList (Z :. 10000) (repeat $ fromFloat 1.01)

	print $ I.run $ esum x
	print $ C.run $ esum x