libff-multipairing.cpp

    GT MultiPairing(const std::vector<G1>& g1, const std::vector<G2>& g2) {
        assertEqual(g1.size(), g2.size());
        using G1_precomp = libff::default_ec_pp::G1_precomp_type;
        using G2_precomp = libff::default_ec_pp::G2_precomp_type;
        using Fqk = libff::default_ec_pp::Fqk_type;

        std::vector<G1_precomp> g1p;
        std::vector<G2_precomp> g2p;

        for(auto el : g1) {
            g1p.push_back(libff::default_ec_pp::precompute_G1(el));
        }

        for(auto el : g2) {
            g2p.push_back(libff::default_ec_pp::precompute_G2(el));
        }

        auto numDblMiller = g1.size() / 2;
        bool singleMiller = (g1.size() % 2 == 1);
        Fqk r = Fqk::one();
        for(size_t i = 0; i < numDblMiller; i++) {
            r = r * libff::default_ec_pp::double_miller_loop(
                g1p[2*i],
                g2p[2*i],
                g1p[2*i + 1],
                g2p[2*i + 1]
            );
        }

        if(singleMiller) {
            r = r * libff::default_ec_pp::miller_loop(
                g1p.back(),
                g2p.back()
            );
        }

        return libff::default_ec_pp::final_exponentiation(r);
    }