Refactor convolution and pooling type prop (#1817)

* WIP

* More WIP

* More chiseling

* Move conv validation utils to a separate file; update unit tests

* Fix invalid attributes in pattern containing ConvolutionBackpropFilters

* Remove zero_const_conv test (it's no longer possible to construct the graph being tested)

* Rename infer_convolution_output_item_shape to infer_windowed_reduction_output_shape and add a boolean flag to control whether window-all-in-padding is allowed

* Add generalized function for inferring pooling fprop, use it in AvgPool/AvgPoolBackprop

* Update MaxPool to use new utility functions

* Fix comment

* Remove faulty and redundant check for window shape relative to pre-padding data shape

* Revert change to pattern construction in cpu_fusion

* Update unit test for maxpool

* Restore unjustly eliminated tests; move some computation to ptrdiff_t for safety; fix wording on some error messages

* Formatting

src/ngraph/CMakeLists.txt

@@ -155,6 +155,7 @@ set (SRC
     strides.cpp
     type/element_type.cpp
     util.cpp
+    validation_util.cpp
     graph_util.cpp
     placement.cpp
     cpio.cpp

src/ngraph/op/convolution.hpp

@@ -356,6 +356,9 @@ namespace ngraph
 
         namespace util
         {
+            // This is a legacy function, retained because the CPU backend uses it for now.
+            // TODO: Update CPU backend to use the new stuff in validation_util.hpp, and remove
+            // this function.
             Shape infer_convolution_output_shape(const Node* node,
                                                  const Shape& data_batch_shape,
                                                  const Shape& filters_shape,

src/ngraph/validation_util.hpp

+//*****************************************************************************
+// Copyright 2017-2018 Intel Corporation
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//*****************************************************************************
+
+#pragma once
+
+#include <tuple>
+
+#include "ngraph/coordinate_diff.hpp"
+#include "ngraph/op/op.hpp"
+
+namespace ngraph
+{
+    Shape infer_windowed_reduction_output_shape(const Node* node,
+                                                const Shape& data_shape,
+                                                const Strides& data_dilation,
+                                                const CoordinateDiff& data_padding_below,
+                                                const CoordinateDiff& data_padding_above,
+                                                const Shape& window_shape,
+                                                const Strides& window_strides,
+                                                const Strides& window_dilation,
+                                                bool is_window_all_in_padding_allowed);
+
+    std::tuple<element::Type, Shape>
+        infer_convolution_forward(const Node* node,
+                                  element::Type et_batch,
+                                  element::Type et_filters,
+                                  const Shape& data_batch_shape,
+                                  const Strides& data_dilation,
+                                  const CoordinateDiff& data_padding_below,
+                                  const CoordinateDiff& data_padding_above,
+                                  const Shape& filters_shape,
+                                  const Strides& filter_strides,
+                                  const Strides& filter_dilation);
+
+    Shape infer_batched_pooling_forward(const Node* node,
+                                        const Shape& data_batch_shape,
+                                        const CoordinateDiff& data_padding_below,
+                                        const CoordinateDiff& data_padding_above,
+                                        const Shape& window_shape,
+                                        const Strides& window_strides,
+                                        bool is_window_all_in_padding_allowed);
+}