out vec4 sk_FragColor; uniform vec4 colorRed; uniform vec4 colorGreen; vec4 main() { bool ok = true; int a = 1; a = a + a; a += a; a = a + a; a += a; a = a + a; ok = ok && a == 32; int b = 10; b = b - 2; b -= 2; b = b - 1; b -= 3; ok = ok && b == 2; int c = 2; c = c * c; c *= c; c = c * 4; c *= 2; ok = ok && c == 128; int d = 256; d = d / 2; d /= 2; d = d / 4; d /= 4; ok = ok && d == 4; return ok ? colorGreen : colorRed; }