- add methods to create and register backend statically

- Option in parent CMakeLists to build cpu as static backend

CMakeLists.txt

@@ -183,6 +183,7 @@ option(NGRAPH_FAST_MATH_ENABLE "Enable fast math" ON)
 option(NGRAPH_JSON_ENABLE "Enable JSON based serialization and tracing features" TRUE)
 option(NGRAPH_STATIC_LIB_ENABLE "Enable build nGraph static library" FALSE)
 option(NGRAPH_INTERPRETER_STATIC_LIB_ENABLE "Enable build INTERPRETER backend static library" FALSE)
+option(NGRAPH_CPU_STATIC_LIB_ENABLE "Enable build CPU backend static library" FALSE)
 
 if (NGRAPH_CPU_ENABLE
         AND

src/ngraph/runtime/cpu/cpu_backend.cpp

@@ -23,6 +23,7 @@
 #include "ngraph/runtime/cpu/cpu_call_frame.hpp"
 #include "ngraph/runtime/cpu/cpu_external_function.hpp"
 #include "ngraph/runtime/cpu/cpu_tensor_view.hpp"
+#include "ngraph/runtime/cpu/static_initialize.hpp"
 #include "ngraph/util.hpp"
 
 #ifdef NGRAPH_MLIR_ENABLE
@@ -32,7 +33,7 @@
 using namespace ngraph;
 using namespace std;
 
-extern "C" runtime::BackendConstructor* get_backend_constructor_pointer()
+runtime::BackendConstructor* runtime::cpu::get_backend_constructor_pointer()
 {
     class CPU_BackendConstructor : public runtime::BackendConstructor
     {
@@ -50,6 +51,23 @@ extern "C" runtime::BackendConstructor* get_backend_constructor_pointer()
     return s_backend_constructor.get();
 }
 
+#ifndef CPU_BACKEND_STATIC
+extern "C" runtime::BackendConstructor* get_backend_constructor_pointer()
+{
+    return runtime::cpu::get_backend_constructor_pointer();
+}
+#endif
+
+void runtime::cpu::static_initialize()
+{
+    static bool s_is_initialized = false;
+    if (!s_is_initialized)
+    {
+        s_is_initialized = true;
+        BackendManager::register_backend("CPU", runtime::cpu::get_backend_constructor_pointer());
+    }
+}
+
 namespace
 {
     static class CPUStaticInit

src/ngraph/runtime/cpu/cpu_backend.hpp

@@ -24,6 +24,7 @@
 #include "ngraph/pass/pass_config.hpp"
 #include "ngraph/runtime/allocator.hpp"
 #include "ngraph/runtime/backend.hpp"
+#include "ngraph/runtime/backend_manager.hpp"
 
 namespace ngraph
 {
@@ -33,7 +34,7 @@ namespace ngraph
         {
             class CPU_ExternalFunction;
             class CPU_CallFrame;
-
+            ngraph::runtime::BackendConstructor* get_backend_constructor_pointer();
             class CPU_BACKEND_API CPU_Backend : public runtime::Backend
             {
             public:

src/ngraph/runtime/cpu/static_initialize.hpp

+//*****************************************************************************
+// Copyright 2017-2019 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
+
+namespace ngraph
+{
+    namespace runtime
+    {
+        namespace cpu
+        {
+            void static_initialize();
+        }
+    }
+}