http://benji3up2kxewkqfcq7buxk2xd6zwy3zggnurkrm3l4cvwy2iipvyyad.onion/mirrors/gmpdoc/FFT-Multiplication.html
The evaluations, pointwise multiplications, and interpolation are all done
modulo 2^N'+1 where N' is 2M+k+3 rounded up to a
multiple of 2^k and of mp_bits_per_limb . The results of
interpolation will be the following negacyclic convolution of the input
pieces, and the choice of N' ensures these sums aren’t truncated. ---
\ b
w[n] = / (-1) * x[i] * y[j]
---
i+j==b*2^k+n
b=0,1 The points used for the...