[Tensor] Update with scale factor support for quantized data types

This pull request aims to enhance the functionality of the Tensor class by enabling it to handle scale factors specifically designed for quantized data types.
This patch ensures tensor class accurately represents and processes quantized data while maintaining original features.
This update will provide developers with more flexibility when working with quantized models

**Self-evaluation:**
1. Build test: [X]Passed [ ]Failed [ ]Skipped
2. Run test:   [X]Passed [ ]Failed [ ]Skipped

Signed-off-by: Donghyeon Jeong <[email protected]>

nntrainer/tensor/tensor.cpp

@@ -1175,6 +1175,8 @@ size_t Tensor::height() const { return itensor->height(); }
 
 size_t Tensor::width() const { return itensor->width(); }
 
+size_t Tensor::scale_size() const { return itensor->scale_size(); }
+
 void Tensor::mergeAxis(unsigned int axis1, unsigned int axis2) {
   NNTR_THROW_IF(!getContiguous(), std::invalid_argument)
     << getName() << " is not contiguous, cannot merge axis";

nntrainer/tensor/tensor.h

@@ -450,6 +450,22 @@ class Tensor {
     return (T *)itensor->getData(idx);
   }
 
+  /**
+   * @brief     return scale pointer of Tensor
+   * @retval    template T pointer
+   */
+  template <typename T = float> T *getScale() const {
+    return (T *)itensor->getScale();
+  }
+
+  /**
+   * @brief     return scale pointer of Tensor
+   * @retval    template T pointer
+   */
+  template <typename T = float> T *getScale(size_t idx) const {
+    return (T *)itensor->getScale(idx);
+  }
+
   /**
    * @brief     i data index
    * @retval    template T pointer (address of ith data)
@@ -1588,6 +1604,12 @@ class Tensor {
    */
   size_t width() const;
 
+  /**
+   * @brief     return Tensor scale factor size if exists
+   * @retval    scale factor size
+   */
+  size_t scale_size() const;
+
   /**
    * @brief Merge the given two axis for tensor at second axis inplace
    *

nntrainer/tensor/tensor_base.h

@@ -188,6 +188,24 @@ class TensorBase {
    */
   virtual void *getData(size_t idx) const = 0;
 
+  /**
+   * @copydoc Tensor::getScale()
+   */
+  virtual void *getScale() const {
+    throw std::invalid_argument(
+      "Tensor::getScale() is not supported in tensor data type " +
+      getStringDataType());
+  }
+
+  /**
+   * @copydoc Tensor::getScale(size_t idx)
+   */
+  virtual void *getScale(size_t idx) const {
+    throw std::invalid_argument(
+      "Tensor::getScale() is not supported in tensor data type " +
+      getStringDataType());
+  }
+
   /**
    * @brief     i data index
    * @retval    address of ith data
@@ -568,7 +586,7 @@ class TensorBase {
    * @brief     Get size of current tensor
    * @retval    unsigned int size of the current tensor
    */
-  size_t size() const { return dim.getDataLen(); }
+  virtual size_t size() const { return dim.getDataLen(); }
 
   /**
    * @brief     Get if the tensor is empty
@@ -606,6 +624,13 @@ class TensorBase {
    */
   size_t width() const { return dim.width(); }
 
+  /**
+   * @brief     return Tensor scale factor size if exists
+   * @retval    scale factor size
+   * @note      Override for quantize tensor
+   */
+  virtual size_t scale_size() const { return 0; }
+
   /**
    * @brief Merge the given two axis for tensor at second axis inplace
    *