I've just added FFT for modular polynomial multiplications when the modulus is small. This enables faster factoring when trying to factor integer polynomials, especially when the number of modular factors is small.
For example, the time required for indicating that x^{900} + 2 is irreducible changed from 12 seconds to 4.7 seconds.
At this moment the bottleneck is the division of polynomials. It appears that I have to implement a divideandconquer approach.
