tinyc | Compiler course project : compile a C-like language

union uint64_t_double {
    uint64_t u;
    double d;
};

uint64_t double_to_uint64_t(double d) {
    union uint64_t_double ud;
    ud.d = d;
    return ud.u;
}

double uint64_t_to_double(int64_t u) {
    union uint64_t_double ud;
    ud.u = u;
    return ud.d;
}