Computes the Ed25519 Base lookup table

ComputeBaseTable.cs

private static void ge_cached_to_precomp(out GroupElementPreComp preComp, ref GroupElementCached cached)
{
    FieldElement invDenominator;
    FieldOperations.fe_invert(out invDenominator, ref cached.Z);

    FieldOperations.fe_mul(out preComp.yminusx, ref cached.YminusX, ref invDenominator);
    FieldOperations.fe_mul(out preComp.yplusx, ref cached.YplusX, ref invDenominator);
    FieldOperations.fe_mul(out preComp.xy2d, ref cached.T2d, ref invDenominator);
}

private static GroupElementPreComp[] ComputeLine(ref GroupElementCached b)
{
    var result = new GroupElementPreComp[8];
    GroupElementP3 p3;

    GroupOperations.ge_p3_0(out p3);
    for (int j = 0; j < 8; j++)
    {
        GroupElementP1P1 p1p1;
        GroupElementCached cached;

        GroupOperations.ge_add(out p1p1, ref p3, ref b);
        GroupOperations.ge_p1p1_to_p3(out p3, ref p1p1);
        GroupOperations.ge_p3_to_cached(out cached, ref p3);

        ge_cached_to_precomp(out result[j], ref cached);
    }
    return result;
}

internal static GroupElementPreComp[][] ComputeTable(ref GroupElementCached b)
{
    var result = new GroupElementPreComp[32][];
    GroupElementP3 p3;
    GroupElementP2 p2;
    GroupElementP1P1 p1p1;
    GroupElementCached cached;

    GroupOperations.ge_p3_0(out p3);
    GroupOperations.ge_add(out p1p1, ref p3, ref b);
    GroupOperations.ge_p1p1_to_p3(out p3, ref p1p1);

    for (int i = 0; i < 32; i++)
    {
        GroupOperations.ge_p3_to_cached(out cached, ref p3);
        result[i] = ComputeLine(ref cached);
        GroupOperations.ge_p3_to_p2(out p2, ref p3);
        for (int k = 0; k < 7; k++)
        {
            GroupOperations.ge_p2_dbl(out p1p1, ref p2);
            GroupOperations.ge_p1p1_to_p2(out p2, ref p1p1);
        }
        GroupOperations.ge_p2_dbl(out p1p1, ref p2);
        GroupOperations.ge_p1p1_to_p3(out p3, ref p1p1);
    }
    return result;
}

internal static GroupElementPreComp[][] ComputeTable()
{
    GroupElementCached cached;
    cached.YplusX = new FieldElement(25967493, -14356035, 29566456, 3660896, -12694345, 4014787, 27544626, -11754271, -6079156, 2047605);
    cached.YminusX = new FieldElement(-12545711, 934262, -2722910, 3049990, -727428, 9406986, 12720692, 5043384, 19500929, -15469378);
    cached.T2d = new FieldElement(-8738181, 4489570, 9688441, -14785194, 10184609, -12363380, 29287919, 11864899, -24514362, -4438546);
    FieldOperations.fe_1(out cached.Z);

    var result = ComputeTable(ref cached);
    return result;
}