Function mqpoly_div_small 

pub fn mqpoly_div_small(
    logn: u32,
    f: &[i8],
    g: &[i8],
    h: &mut [u16],
    tmp: &mut [u16],
)

Compute h = g/f mod X^n+1 mod q.

This function assumes that f is invertible. Output is in external representation (coefficients are in [0,q-1]).