IIRC (it's been a long time) the Cray 1 could do inverse, multiply, and square root in single cycle instructions. Isqrt would take two cycles as wood divide. (Back to the rocking chair.)
But even if a certain computer did compute a square root (or even an approximation) in a single cycle, that would mean CPU speed was reduced by slowing down the clock to enable a more complex action to complete within the timeframe of a single cycle, and other simpler actions like adding/subtracting/moving memory we're sacrificed in its favor.