They could, but it's less profitable, and cost models are, as always, a big problem. If we have: loop for i from 0 to n f(a[i]/y) How big does n have

They could, but it's less profitable, and cost models are, as always, a big problem. If we have: loop for i from 0 to n f(a[i]/y) How big does n have to be before it makes sense to compute a reciprocal for y? And how frequently is it actually that big during the runtime of the code?