message: Use the rsqrt function instead of 1/sqrt.
  This could be faster (many architectures have native rsqrt instructions), and required to be more precise by the OpenCL standard.
diff: @@ -59,7 +59,7 @@ std::string GetOneInputCode(const OperationType& op_type,
  result = "$0 = log($0);\n";
  break;
  case OperationType::RSQRT:
  - result = "$0 = (FLT4)(1.0f) / sqrt($0);\n";
  + result = "$0 = rsqrt($0);\n";
  break;
  case OperationType::SIGMOID:
  if (precision != CalculationsPrecision::F32) {
  