message: Introduce a switch to disable depthwise backprop filter optimizations.
diff: @@ -223,7 +223,7 @@ Status ConvolutionVisitor::HandleBatchGroupCount(HloInstruction* convolution) {
  // We are not yet supporting batch_group of sizes greater than 1.
  TF_RET_CHECK(input_batch == batch_group_count);
  - if (!is_cost_viable_(convolution)) {
  + if (!is_cost_viable_(convolution) || filter_expansion_) {
  // We first obtain the expanded the filter (which is the convolution
  // output). The batch dimension is the expanded one (which originally
  // represents kernel input feature dimension). We mask the filter to zero
  