1 files changed, 115 insertions, 0 deletions
diff --git a/compiler/exo/src/Pass/FuseReluPass.cpp b/compiler/exo/src/Pass/FuseReluPass.cpp
new file mode 100644
index 000000000..d7af0c506
--- /dev/null
+++ b/compiler/exo/src/Pass/FuseReluPass.cpp
@@ -0,0 +1,115 @@
+/*
+ * Copyright (c) 2019 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 "FuseReluPass.h"
+
+#include "Dialect/IR/TFLNodes.h"
+#include "Dialect/IR/TFLDialect.h"
+#include "Dialect/IR/TFLNodeVisitor.h"
+
+#include <set>
+
+namespace
+{
+
+bool is_pred_fusable(loco::Node *node)
+{
+  using namespace locoex;
+
+  auto fusable_node = dynamic_cast<TFLNodeMixin<TFLNodeTrait::FusedActFunc> *>(node);
+
+  return (fusable_node and fusable_node->fusedActivationFunction() == FusedActFunc::NONE);
+};
+
+struct Collector final : public locoex::TFLNodeMutableVisitor<void>
+{
+  void visit(locoex::TFLRelu *node) final
+  {
+    if (is_pred_fusable(node->features()))
+      candidates.insert(node);
+  }
+
+  void visit(locoex::TFLRelu6 *node) final
+  {
+    if (is_pred_fusable(node->features()))
+      candidates.insert(node);
+  }
+
+  void visit(locoex::TFLNode *) final { return; }
+
+  std::set<locoex::TFLNode *> candidates;
+};
+
+void set_activation_fusion(loco::Node *node, locoex::FusedActFunc f)
+{
+  using namespace locoex;
+
+  if (auto fusable_node = dynamic_cast<TFLNodeMixin<TFLNodeTrait::FusedActFunc> *>(node))
+    fusable_node->fusedActivationFunction(f);
+  else
+    assert(false);
+}
+
+struct Performer final : public locoex::TFLNodeMutableVisitor<void>
+{
+  void visit(locoex::TFLRelu *the_relu) final
+  {
+    set_activation_fusion(the_relu->features(), locoex::FusedActFunc::RELU);
+
+    loco::replace(the_relu).with(the_relu->features());
+    the_relu->features(nullptr);
+  }
+
+  void visit(locoex::TFLRelu6 *the_relu6) final
+  {
+    set_activation_fusion(the_relu6->features(), locoex::FusedActFunc::RELU6);
+
+    loco::replace(the_relu6).with(the_relu6->features());
+    the_relu6->features(nullptr);
+  }
+
+  void visit(locoex::TFLNode *) final { assert(false && "should not be called"); }
+};
+
+} // namespace
+
+namespace exo
+{
+
+bool FuseReluPass::run(loco::Graph *g)
+{
+  Collector collector;
+
+  for (auto node : loco::active_nodes(loco::output_nodes(g)))
+  {
+    if (node->dialect() == locoex::TFLDialect::get())
+    {
+      auto tfl_node = dynamic_cast<locoex::TFLNode *>(node);
+      tfl_node->accept(&collector);
+    }
+  }
+
+  Performer performer;
+
+  for (auto node : collector.candidates)
+  {
+    node->accept(&performer);
+  }
+
+  return collector.candidates.size() > 0;
+}
+
+} // namespace exo