cudnnFind/Get interoperability (#1721)

* add find algorithm for convolution without extra padding

* Use cudnnFind* or cudnnGet* depending on tuning param boolean. Add select function to search the perf results of the cudnn queries.

* Formatting.

* Algo search no longer binary, now it is either off, a heuristic search (cudnnGet*) or an explicit search (cudnnFind*).

* Formatting.

* switch to explicit.

* Throw if no suitable cudnn algo found.

* Formatting

* Remove comment.

src/ngraph/runtime/gpu/cudnn_emitter.hpp

@@ -72,6 +72,13 @@ namespace ngraph
                     Backward
                 };
 
+                enum class algo_search
+                {
+                    HEURISTIC,
+                    EXPLICIT,
+                    NONE
+                };
+
                 size_t build_convolution(const std::string& dtype,
                                          const Shape& input_tensor_shape,
                                          const Shape& input_filter_shape,
@@ -79,25 +86,27 @@ namespace ngraph
                                          const Strides& window_movement_strides,
                                          const Strides& window_dilation_strides,
                                          const Shape& padding_below,
-                                         const bool find_algo = false);
+                                         const algo_search find_algo = algo_search::NONE);
 
-                size_t build_convolution_backward_data(const std::string& dtype,
+                size_t build_convolution_backward_data(
+                    const std::string& dtype,
                     const Shape& input_filter_shape,
                     const Shape& input_tensor_shape,
                     const Shape& output_tensor_shape,
                     const Strides& window_movement_strides,
                     const Strides& window_dilation_strides,
                     const Shape& padding_below,
-                                                       const bool find_algo = false);
+                    const algo_search find_algo = algo_search::NONE);
 
-                size_t build_convolution_backward_filter(const std::string& dtype,
+                size_t build_convolution_backward_filter(
+                    const std::string& dtype,
                     const Shape& input_tensor_shape_0,
                     const Shape& input_tensor_shape_1,
                     const Shape& output_filter_shape,
                     const Strides& window_movement_strides,
                     const Strides& window_dilation_strides,
                     const Shape& padding_below,
-                                                         const bool find_algo = false);
+                    const algo_search find_algo = algo_search::NONE);
 
                 size_t build_reduce_forward(const cudnnReduceTensorOp_t& reduce_op,
                                             const std::string& dtype,
@@ -178,6 +187,24 @@ namespace ngraph
                                                      cudnnConvolutionMode_t mode,
                                                      cudnnDataType_t data_type);
 
+                template <typename PERF_TYPE, typename ALGO_TYPE>
+                ALGO_TYPE
+                    select_cudnn_algo(const std::vector<PERF_TYPE>& perf_results,
+                                      size_t workspace_byte = std::numeric_limits<size_t>::max())
+                {
+                    for (auto i = 0; i != perf_results.size(); ++i)
+                    {
+                        auto const& result = perf_results[i];
+                        if (result.status == CUDNN_STATUS_SUCCESS &&
+                            result.memory <= workspace_byte)
+                        {
+                            return result.algo;
+                        }
+                    }
+                    throw ngraph_error(
+                        "No suitable cuDNN algorithm was found for the requested operation.");
+                }
+
                 CUDNNDescriptors m_descriptors;
                 CUDNNHostParameters m_host_parameters;