Struct_u64_u64 = struct
{
    a: u64,
    b: u64,
}

return_struct_u64_u64 = fn [cc(c)] () Struct_u64_u64
{
    return { .a = 1, .b = 2 };
}

[export] main = fn [cc(c)] () s32
{
    >r = return_struct_u64_u64();
    return #truncate(r.a + r.b - 3);
}