message: Defend against unequal paddings (not supported by poplar at the moment)
diff: @@ -83,6 +83,15 @@ CreateConv2D(poplar::Graph &graph,
  unsigned int p_y = window.dimensions(0).padding_low();
  unsigned int p_x = window.dimensions(1).padding_low();
  + if (window.dimensions(0).padding_low() !=
  + window.dimensions(0).padding_high() ||
  + window.dimensions(1).padding_low() !=
  + window.dimensions(1).padding_high()) {
  + return port::Status(
  + port::error::FAILED_PRECONDITION,
  + port::StrCat("Unequal paddings not supported on ", inst->name()));
  + }
  +
  popconv::Plan plan = popconv::getPlan(graph,
  dtype,
  n_b,
  