I’m trying to calculate the cost of a function izq where I use the function div inside:

izq n   | even (n - 1)  = ((n - 1) `div` 2)
        | otherwise     = (((n - 1) `div` 2) + 1)

So work of izq is 1 + the cost of div applied to (n – 1). However, I’m unsure about the cost of div. Does anyone know the typical cost of the div function in Haskell?