polyreduce function

Poly polyreduce(
  1. Poly a
)

Reduces all coefficients of a polynomial mod q.

This function iterates over all coefficients in the polynomial a and applies the Barrett reduction algorithm to each coefficient, reducing it modulo q. The result is a new polynomial with coefficients that are all reduced modulo q.

Implementation

Poly polyreduce(Poly a) {
  for (int i = 0; i < KYBER_N; i++) {
    a.coeffs[i] = barrettreduce(a.coeffs[i]);
  }
  return a;
}