.hs

-- Specialization of return
plus_Retn :: Int -> Int -> Int#
plus_Retn (I# a) (I# b) = a +# b

(+) :: Int -> Int -> Int
a + b = I# (plus_Retn a b)

-- Specialization of arguments
plus_Retn2 :: Int# -> Int# -> Int#
plus_Retn2 a b = a +# b

plus_Retn1 :: Int# -> Int -> Int#
plus_Retn1 a b = case b of { I# b' -> plus_Retn2 a b' }

plus_Retn :: Int -> Int -> Int#
plus_Retn a b = case a of { I# a' -> plus_Retn1 a' b }

(+) :: Int -> Int -> Int
a + b = I# (plus_Retn a b)