pub fn masked_sub(a: &MaskedPoly, b: &MaskedPoly, c: &mut MaskedPoly)Expand description
Subtract two masked polynomials share-wise.
Computes c.share0 = a.share0 - b.share0 and
c.share1 = a.share1 - b.share1, so
unmask(c) = unmask(a) - unmask(b) mod q.