4 ms·
An example is efficient prime-field arithmetic: https://cp4space.hatsya.com/2021/09/01/an-efficient-prime-for-number-theoretic-transforms/ https://cp4space.hat
by sshine 4y ago
An example is efficient prime-field arithmetic:
https://cp4space.hatsya.com/2021/09/01/an-efficient-prime-for-number-theoretic-transforms/ https://cp4space.hatsya.com/2021/09/01/an-efficient-prime-fo...
> If A happened to be larger than C, and therefore the result of the subtraction underflowed, then we can correct for this by adding p to the result. [...] we can multiply B by 2^32 using a binary shift and a subtraction, and then add it to the result. We might encounter an overflow, but we can correct for that by subtracting p.
(Highlighting the parts that relate to reacting to overflow.)