CPU Direct Execution: Implement FunctionCall

src/ngraph/runtime/cpu/builder/function_call.cpp

+/*******************************************************************************
+* Copyright 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.
+*******************************************************************************/
+
+#include "ngraph/op/function_call.hpp"
+#include "ngraph/runtime/backend.hpp"
+#include "ngraph/runtime/cpu/cpu_builder.hpp"
+#include "ngraph/runtime/tensor_view.hpp"
+
+using namespace std;
+using namespace ngraph;
+
+namespace ngraph
+{
+    namespace runtime
+    {
+        namespace cpu
+        {
+            template <>
+            void Builder::BUILDER_DECL(ngraph::op::FunctionCall)
+            {
+                auto function_call = static_cast<const ngraph::op::FunctionCall*>(node);
+                auto function = function_call->get_functions()[0];
+                auto backend = runtime::Backend::create("CPU");
+
+                auto& functors = external_function->get_functors();
+                auto& tensor_data = external_function->get_tensor_data();
+                auto& callees = external_function->get_callees();
+
+                // Note: We bypass the completely broken ngraph "backend" API here
+                vector<reference_wrapper<void *>> arg_tensors, out_tensors;
+                vector<Shape> arg_shapes, out_shapes;
+                vector<element::Type> arg_types, out_types;
+
+                for (const auto& arg : args)
+                {
+                    arg_shapes.emplace_back(arg.get_shape());
+                    arg_types.emplace_back(arg.get_element_type());
+                    arg_tensors.emplace_back(tensor_data[arg.get_name()]);
+                }
+
+                for (const auto& result : out)
+                {
+                    out_shapes.emplace_back(result.get_shape());
+                    out_types.emplace_back(result.get_element_type());
+                    out_tensors.emplace_back(tensor_data[result.get_name()]);
+                }
+
+                if (!callees.count(function->get_name()))
+                {
+                    callees[function->get_name()] = make_shared<CPU_ExternalFunction>(function);
+                }
+
+                auto& callee_external_function = callees[function->get_name()];
+
+                auto functor = [&,
+                                backend,
+                                arg_shapes,
+                                arg_types,
+                                arg_tensors,
+                                out_shapes,
+                                out_types,
+                                out_tensors](CPURuntimeContext* ctx) {
+                    TensorViewPtrs inputs, outputs;
+                    for (int i = 0; i < arg_shapes.size(); i++)
+                    {
+                        inputs.emplace_back(
+                            backend->create_tensor(arg_types[i], arg_shapes[i], arg_tensors[i]));
+                    }
+                    for (int i = 0; i < out_shapes.size(); i++)
+                    {
+                        outputs.emplace_back(
+                            backend->create_tensor(out_types[i], out_shapes[i], out_tensors[i]));
+                    }
+
+                    auto call_frame = callee_external_function->make_call_frame();
+                    call_frame->call(outputs, inputs);
+                };
+                functors.emplace_back(functor);
+            }
+
+            REGISTER_OP_BUILDER(FunctionCall);
+        }
+    }
+}