Make temp memory pools static to avoid memory allocation overheads (#941)

src/ngraph/runtime/cpu/cpu_external_function.cpp

@@ -551,6 +551,30 @@ using namespace ngraph::runtime;
             }
         }
 
+        bool temporaries_used = false;
+        size_t worst_case_tmp_size = 0;
+        for (shared_ptr<Node> node : ordered_ops)
+        {
+            if (node->liveness_new_list.size() > 0)
+            {
+                temporaries_used = true;
+                for (descriptor::Tensor* tensor : node->liveness_new_list)
+                {
+                    worst_case_tmp_size += tensor->size();
+                }
+            }
+        }
+        if (temporaries_used)
+        {
+            size_t temp_pool_size = current_function->get_temporary_pool_size();
+            writer << "// Allocate the memory pool\n";
+            writer << "// Memory pool size is " << temp_pool_size << " bytes\n";
+            writer << "// Worst case size is " << worst_case_tmp_size << " bytes\n";
+            writer << "ngraph::runtime::AlignedBuffer " << current_function->get_name()
+                   << "_memory_handler(" << temp_pool_size << ", " << s_memory_pool_alignment
+                   << ");\n";
+        }
+
         writer << "extern \"C\" void " << current_function->get_name();
         writer << "(void** inputs, void** outputs, cpu::CPURuntimeContext* ctx)\n";
         writer << "{\n";
@@ -569,28 +593,10 @@ using namespace ngraph::runtime;
                    << "int profiler_count = 0;\n\n";
         }
 
-        bool temporaries_used = false;
-        size_t worst_case_tmp_size = 0;
-        for (shared_ptr<Node> node : ordered_ops)
-        {
-            if (node->liveness_new_list.size() > 0)
-            {
-                temporaries_used = true;
-                for (descriptor::Tensor* tensor : node->liveness_new_list)
-                {
-                    worst_case_tmp_size += tensor->size();
-                }
-            }
-        }
         if (temporaries_used)
         {
-            size_t temp_pool_size = current_function->get_temporary_pool_size();
-            writer << "// Allocate the memory pool\n";
-            writer << "// Memory pool size is " << temp_pool_size << " bytes\n";
-            writer << "// Worst case size is " << worst_case_tmp_size << " bytes\n";
-            writer << "ngraph::runtime::AlignedBuffer memory_handler(" << temp_pool_size << ", "
-                   << s_memory_pool_alignment << ");\n";
-            writer << "size_t pool_base_ptr = (size_t)memory_handler.get_ptr();\n";
+            writer << "size_t pool_base_ptr = (size_t)" << current_function->get_name()
+                   << "_memory_handler.get_ptr();\n";
             writer << "\n";
 
             // Add temporaries to the variable name map