uniform half4 colorGreen, colorRed;

bool out_params_are_distinct(out half x, out half y) {
    x = 1;
    y = 2;
    return x == 1 && y == 2;
}

half4 main(float2 coords) {
    half x = 0;
    return out_params_are_distinct(x, x) ? colorGreen : colorRed;
}