you save transistors but not dealing with NaNs and Infs also. you also save some because your comparison operations just use signed integer comparison so you do

you save transistors but not dealing with NaNs and Infs also. you also save some because your comparison operations just use signed integer comparison so you don't need hardware to do those. my guess is that when you combine these effects it could be a net win for 16 bit. also bigger multipliers might be slightly sub-quadratic by using karatsuba or similar.