- use static_initilize to explicitly regreister the backend for cpu

src/ngraph/runtime/backend_manager.cpp

@@ -74,6 +74,10 @@ shared_ptr<runtime::Backend> runtime::BackendManager::create_backend(const std::
     runtime::interpreter::static_initialize();
 #endif
 
+#ifdef NGRAPH_CPU_STATIC_LIB_ENABLE
+    runtime::cpu::static_initialize();
+#endif
+
     shared_ptr<runtime::Backend> backend;
     string type = config;
 

src/ngraph/runtime/cpu/cpu_backend.cpp

@@ -58,6 +58,16 @@ extern "C" runtime::BackendConstructor* 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