message: Skip VectorVectorCwiseProduct when cell_state is known to be all zeros.
diff: @@ -702,8 +702,10 @@ inline void LstmStepWithAuxInput(
  forget_gate_scratch);
  // For each batch and cell: update the cell.
  + if (!is_cell_state_all_zeros) {
  tensor_utils::VectorVectorCwiseProduct(forget_gate_scratch, cell_state_ptr,
  n_batch * n_cell, cell_state_ptr);
  + }
  if (is_layer_norm_lstm) {
  tensor_utils::MeanStddevNormalization(cell_scratch, cell_scratch, n_cell,
  n_batch);
  