[onert] Introduce backpropActivation to OperationUtils

This PR adds backpropActivation function to the Operation Utility.
The function is to call proper ckernel according to an ir::Activation.

ONE-DCO-1.0-Signed-off-by: SeungHui Youn <[email protected]>

runtime/onert/backend/train/ops/ElementwiseActivationLayer.cc

@@ -78,8 +78,8 @@ void ElementwiseActivationLayer::configure(const IPortableTensor *input, IPortab
         }
         else
         {
-          throw std::runtime_error("train ElementwiseActivationLayer : This layer does not "
-                                   "suppport other ReLU except for ReLU(0-inf) and ReLU6(0-6)");
+          throw std::runtime_error(
+            "train ElementwiseActivationLayer : Unsupported ReLU activation type");
         }
       }
       else

runtime/onert/backend/train/ops/OperationUtils.cc

@@ -0,0 +1,69 @@
+/*
+ * 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.
+ */
+
+#include "OperationUtils.h"
+
+#include <cker/train/operation/ReLU.h>
+#include <cker/train/operation/ReLU6.h>
+
+namespace onert
+{
+namespace backend
+{
+namespace train
+{
+namespace ops
+{
+
+const IPortableTensor *backpropActivation(const ir::Activation &activation,
+                                          const IPortableTensor *output,
+                                          const IPortableTensor *input_backprop,
+                                          IPortableTensor *output_backprop)
+{
+  if(activation == ir::Activation::NONE)
+    assert(output_backprop != nullptr);
+
+  const IPortableTensor *res;
+  switch (activation)
+  {
+    case ir::Activation::NONE:
+      res = input_backprop;
+      break;
+    case ir::Activation::RELU:
+      nnfw::cker::train::ReLUGrad(getShape(output), getBuffer<float>(output),
+                                  getShape(input_backprop), getBuffer<float>(input_backprop),
+                                  getShape(output_backprop), getBuffer<float>(output_backprop));
+      res = output_backprop;
+      break;
+    case ir::Activation::RELU6:
+      nnfw::cker::train::ReLU6Grad(getShape(output), getBuffer<float>(output),
+                                   getShape(input_backprop), getBuffer<float>(input_backprop),
+                                   getShape(output_backprop), getBuffer<float>(output_backprop));
+      res = output_backprop;
+      break;
+    default:
+      throw std::runtime_error("Unsupported activation type yet");
+  }
+
+  return res;
+}
+
+} // namespace ops
+} // namespace train
+} // namespace backend
+} // namespace onert
+
+