Extended-width multiplication works, but the cost of extra random bits is often a lot higher than the range arithmetic.
Somewhere in my github there's an indefinite-width multiply that only adds bits while there's a risk of carry into the 1's digit; the check for that is quite cheap.
Somewhere in my github there's an indefinite-width multiply that only adds bits while there's a risk of carry into the 1's digit; the check for that is quite cheap.