sub FNV_1_128_gmpn {
    my $s = shift;
    mpn_set_str(my $h, '144066263297769815596495629667062367629', 10, 128);
    mpn_set_str(my $p, '309485009821345068724781371', 10, 128);
    for (unpack 'C*', $s) {
        my $h2 = $h;
        mpn_mul($h, $h2, $p);
        mpn_ior_uint($h, $h, $_);
    }
    return $h;
}

sub FNV_1a_128_gmpn {
    my $s = shift;
    mpn_set_str(my $h, '144066263297769815596495629667062367629', 10, 128);
    mpn_set_str(my $p, '309485009821345068724781371', 10, 128 );
    for (unpack 'C*', $s) {
        mpn_ior_uint($h, $h, $_);
        my $h2 = $h;
        mpn_mul($h, $h2, $p);
    }
    return $h;
}