message: Use native_rsqrt in MeanStdDevNormalization. It seems to have enough precision on tested hardware.
diff: @@ -135,7 +135,7 @@ std::string MeanStdDevNormalization::GetNormalizationCode() {
  const float sum_diff_sq = local_reduce(private_sum_diff_sq, tmp);
  // Calculate 1/stddev (with the 'regulazing constant' as in tensor_utils.cc)
  const float variance = sum_diff_sq / args.src_tensor.Channels();
  - const float stddev_inv = rsqrt(variance + 1.0e-8f);
  + const float stddev_inv = native_rsqrt(variance + 1.0e-8f);
  // Calculate (t-mean)/stddev for each element
  for (int S = get_local_id(0); S < args.src_tensor.Slices(); S += get_local_size(0)) {
  const float4 t = args.src_tensor.Read<float>(0, 0, S, B);
  