1use super::*;
 2use ark_ff::{field_new, fields::*};
 3
 4pub type Fq2 = Fp2<Fq2Parameters>;
 5
 6pub struct Fq2Parameters;
 7
 8impl Fp2Parameters for Fq2Parameters {
 9    type Fp = Fq;
10
11    /// NONRESIDUE = -5
12    #[rustfmt::skip]
13    const NONRESIDUE: Fq = field_new!(Fq, "-5");
14
15    /// QUADRATIC_NONRESIDUE = U
16    #[rustfmt::skip]
17    const QUADRATIC_NONRESIDUE: (Fq, Fq) = (FQ_ZERO, FQ_ONE);
18
19    /// Coefficients for the Frobenius automorphism.
20    #[rustfmt::skip]
21    const FROBENIUS_COEFF_FP2_C1: &'static [Fq] = &[
22        // NONRESIDUE**(((q^0) - 1) / 2)
23        FQ_ONE,
24        // NONRESIDUE**(((q^1) - 1) / 2)
25        field_new!(Fq, "-1"),
26    ];
27
28    // Mul by -5
29    #[inline(always)]
30    fn mul_fp_by_nonresidue(fe: &Self::Fp) -> Self::Fp {
31        let original = fe;
32        let mut fe = -fe.double();
33        fe.double_in_place();
34        fe - original
35    }
36
37    // x + -5 * y, computed as x - 5*y
38    #[inline(always)]
39    fn add_and_mul_fp_by_nonresidue(x: &Self::Fp, y: &Self::Fp) -> Self::Fp {
40        // c becomes 5 * y
41        let mut c = y.double();
42        c.double_in_place();
43        c += y;
44        *x - c
45    }
46
47    // x - (-5 * y), computed as x + 5*y
48    #[inline(always)]
49    fn sub_and_mul_fp_by_nonresidue(x: &Self::Fp, y: &Self::Fp) -> Self::Fp {
50        // c becomes 5 * y
51        let mut c = y.double();
52        c.double_in_place();
53        c += y;
54        *x + c
55    }
56}
57
58pub const FQ2_ZERO: Fq2 = field_new!(Fq2, FQ_ZERO, FQ_ZERO);
59pub const FQ2_ONE: Fq2 = field_new!(Fq2, FQ_ONE, FQ_ZERO);