Even better / potentially more surprising: unsigned mult(unsigned x, unsigned y) { unsigned y0 = y; while (x--) y = add_v1(y, y0);

Even better / potentially more surprising: unsigned mult(unsigned x, unsigned y) { unsigned y0 = y; while (x--) y = add_v1(y, y0); return y; } optimizes to: mult(unsigned int, unsigned int): madd w0, w1, w0, w1 ret (and this produces the same result when substituting any of the `add_vN`s from TFA)