uniform half4 colorGreen, colorRed;

half4 main() {
  const float4 a = float4(0);
  const float4 b = float4(1);
  const float4 c = abs(b);  // still a Constant Expression, but SkSL cannot eliminate it (today)
  if (a == b || b != c) {
      return colorRed;
  } else {
      return colorGreen;
  }
}