message: [XLA] Add a reduce-window test.
  REL_NOTES:n/a
diff: @@ -252,6 +252,31 @@ TEST_P(ReduceWindowTest, AmongMajor2DimsMediumSize) {
  DefaultErrorSpec());
  }
  +// Tests the super windowing logic w.r.t handling prime number of windows in a
  +// major dimension with reduction.
  +TEST_P(ReduceWindowTest, PrimeWindowsInReductionDimension) {
  + Array4D<float> input_array(15, 15, 4, 128);
  + input_array.FillRandom(2.f, 4.f);
  +
  + int win_len = 3;
  + int win_stride = 2;
  +
  + const auto input_data_handle =
  + CreateConstantFromArray(input_array, &builder_);
  +
  + Padding padding = Padding::kSame;
  + // Reduce only along the x and y dimensions, according to the win_len.
  + ReduceWindowAdd(input_data_handle, {win_len, win_len, 1, 1},
  + {win_stride, win_stride, 1, 1}, padding);
  +
  + auto result = ReferenceUtil::ReduceWindow4DAdd(
  + input_array, 0.0f, {win_len, win_len, 1, 1},
  + {win_stride, win_stride, 1, 1}, padding);
  +
  + ComputeAndCompareLiteral(&builder_, *Literal::CreateFromArray(*result), {},
  + DefaultErrorSpec());
  +}
  +
  // Tests a reduction function that is not a simple add/min/max/etc.
  XLA_TEST_P(ReduceWindowTest, NonstandardReduceFunction) {
  Array4D<float> input_array(1, 2, 2, 1);
  