1 files changed, 48 insertions, 0 deletions
diff --git a/compiler/nnc/passes/optimizations/DeadCodeElimination.cpp b/compiler/nnc/passes/optimizations/DeadCodeElimination.cpp
new file mode 100644
index 000000000..b89dca1b7
--- /dev/null
+++ b/compiler/nnc/passes/optimizations/DeadCodeElimination.cpp
@@ -0,0 +1,48 @@
+/*
+ * Copyright (c) 2020 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 "passes/optimizations/DeadCodeElimination.h"
+#include "mir/Graph.h"
+
+#include <algorithm>
+
+using namespace mir;
+
+nnc::PassData nnc::DeadCodeElimination::run(PassData data)
+{
+  auto graph = static_cast<Graph *>(data);
+  assert(graph);
+
+  std::vector<Operation *> sorted_nodes = getSortedNodes(graph);
+
+  auto remove_if_unused = [graph](Operation *op) {
+    if (op->getType() == Operation::Type::input || op->getType() == Operation::Type::output)
+      return;
+
+    bool has_no_uses =
+        std::all_of(op->getOutputs().cbegin(), op->getOutputs().cend(),
+                    [](const Operation::Output &output) { return output.getUses().empty(); });
+
+    if (has_no_uses)
+    {
+      graph->removeNode(op);
+    }
+  };
+
+  std::for_each(sorted_nodes.rbegin(), sorted_nodes.rend(), remove_if_unused);
+
+  return graph;
+}