[onert] Introduce ExtraTensor

This PR introduces ExtraTensor.
ExtraTensor means that the tensor is only used by one operation.

ONE-DCO-1.0-Signed-off-by: seunghui youn <[email protected]>

runtime/onert/core/include/backend/train/ExtraTensor.h

@@ -0,0 +1,47 @@
+/*
+ * Copyright (c) 2024 Samsung Electronics Co., Ltd. All Rights Reserved
+ *
+ * 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.
+ */
+
+#ifndef __ONERT_BACKEND_EXTRA_H__
+#define __ONERT_BACKEND_EXTRA_H__
+
+#include <backend/basic/Tensor.h>
+
+namespace onert
+{
+namespace backend
+{
+namespace train
+{
+
+// ExtraTensor is a tensor that is accessed only by one opeartion layer.
+// In other word, Extra tensor's scope is limited into a specific layer.
+class ExtraTensor final : public basic::Tensor
+{
+public:
+  ExtraTensor() = delete;
+
+public:
+  ExtraTensor(const ir::OperandInfo &info) : basic::Tensor(info, nullptr)
+  {
+    // DO NOTHING
+  }
+};
+
+} // namespace train
+} // namespace backend
+} // namespace onert
+
+#endif // __ONERT_BACKEND_EXTRA_TENSOR_H__