uniform half4 colorGreen, colorRed;

half4 main(float2 xy) {
    int one  = int(colorGreen.g);
    int zero = int(colorGreen.r);
    int undefined = (one / zero) + (zero / zero);

    // We have to use the result somehow, in order to prevent dead-code elimination.
    return (undefined != 9876543) ? colorGreen : colorRed;
}