message: Incorporate Adrian's comments
diff: @@ -155,8 +155,8 @@ MatchBackwardFilter(HloInstruction* conv) {
  }
  auto rhs_in =
  conv->mutable_operand(1)->shape().dimensions(kernel_input_feature_dim);
  - if ((conv->feature_group_count() > 1) && (rhs_in == 1) &&
  - (input_batch_dim == output_batch_dim)) {
  + if (conv->feature_group_count() > 1 && rhs_in == 1 &&
  + input_batch_dim == output_batch_dim) {
  VLOG(1) << conv->ToString()
  << " is a depthwise forward convolution. No need to fold to "
  "backward filter.";
  @@ -270,8 +270,7 @@ MatchBackwardFilter(HloInstruction* conv) {
  // Reshape batch_dim G*N -> [G,N]
  std::vector<int64> reshape_dims = lhs->shape().dimensions();
  auto num_groups = conv->feature_group_count();
  - // Ensure that input_batch is exact multiple of conv->feature_group_count()
  - CHECK_EQ(input_batch % conv->feature_group_count(), 0)
  + CHECK_EQ(input_batch % num_groups, 0)
  << "Input batch should be an exact multiple of feature group count";
  reshape_dims[input_batch_dimension] =
  reshape_dims[input_batch_dimension] / num_groups;
  