half4 main(float2 xy) { int i; for (int a = 0;a < 10; ++a) { for (int b = 0;b < 10; ++b) { for (int c = 0;c < 10; ++c) { for (int d = 0;d < 10; ++d) { ++i; } } } } return half4(half4(0.0)); }