From 49472489ffc8bc85148e4cbe0ed878131320a8cc Mon Sep 17 00:00:00 2001
From: =?utf8?q?=EB=B0=95=EC=84=B8=ED=9D=AC/On-Device=20Lab=28SR=29/Princip?=
 =?utf8?q?al=20Engineer/=EC=82=BC=EC=84=B1=EC=A0=84=EC=9E=90?=
 <saehie.park@samsung.com>
Date: Mon, 5 Aug 2019 16:07:54 +0900
Subject: [PATCH] [moco-tf] Canonicalize TFRelu (#6195)

This will add ReluCanonicalizer that transforms TFRelu node to canonical ReLU node

Signed-off-by: SaeHie Park <saehie.park@samsung.com>
---
 .../src/Canonicalization/ReluCanonicalizer.cpp     | 89 ++++++++++++++++++++++
 .../src/Canonicalization/ReluCanonicalizer.h       | 44 +++++++++++
 2 files changed, 133 insertions(+)
 create mode 100644 compiler/moco-tf/src/Canonicalization/ReluCanonicalizer.cpp
 create mode 100644 compiler/moco-tf/src/Canonicalization/ReluCanonicalizer.h

diff --git a/compiler/moco-tf/src/Canonicalization/ReluCanonicalizer.cpp b/compiler/moco-tf/src/Canonicalization/ReluCanonicalizer.cpp
new file mode 100644
index 0000000..20cd0ba
--- /dev/null
+++ b/compiler/moco-tf/src/Canonicalization/ReluCanonicalizer.cpp
@@ -0,0 +1,89 @@
+/*
+ * 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 "ReluCanonicalizer.h"
+
+#include "Dialect/TFDialect.h"
+#include "Dialect/TFNodes.h"
+#include "Dialect/TFNodeVisitor.h"
+#include "Dialect/TFNodeImpl.h"
+
+#include <stdex/Memory.h>
+
+namespace
+{
+
+bool canonicalize_relu(loco::Graph *graph, moco::tf::TFRelu *node)
+{
+  /**
+   * @note This will replace TFRelu node with Canonical ReLU
+   *
+   *       Before
+   *                 A --- TFRelu -- C
+   *       After
+   *                    +- TFRelu --
+   *                    |
+   *                 A -+- ReLU -- C
+   *
+   *       Where
+   *                 A : features of TFRelu
+   *                 C : a node that uses TFRelu as an input
+   *                 TFRelu is disconnected from C
+   */
+
+  auto relu_node = graph->nodes()->create<loco::ReLU>();
+
+  auto node_A = node->features();
+
+  // update connections
+  relu_node->input(node_A);
+
+  // replace node
+  replace(node).with(relu_node);
+
+  return true;
+}
+
+} // namespace
+
+namespace moco
+{
+namespace tf
+{
+
+bool ReluCanonicalizer::run(loco::Graph *graph)
+{
+  auto active_nodes = loco::active_nodes(loco::output_nodes(graph));
+  bool changed = false;
+
+  for (auto node : active_nodes)
+  {
+    if (node->dialect() == TFDialect::get())
+    {
+      auto tf_node = dynamic_cast<moco::tf::TFRelu *>(node);
+      if (tf_node != nullptr)
+      {
+        if (canonicalize_relu(graph, tf_node))
+          changed = true;
+      }
+    }
+  }
+
+  return changed;
+}
+
+} // namespace tf
+} // namespace moco
diff --git a/compiler/moco-tf/src/Canonicalization/ReluCanonicalizer.h b/compiler/moco-tf/src/Canonicalization/ReluCanonicalizer.h
new file mode 100644
index 0000000..97adba3
--- /dev/null
+++ b/compiler/moco-tf/src/Canonicalization/ReluCanonicalizer.h
@@ -0,0 +1,44 @@
+/*
+ * 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.
+ */
+
+#ifndef __MOCO_TF_RELU_CANONICALIZER_H__
+#define __MOCO_TF_RELU_CANONICALIZER_H__
+
+#include "Transform.h"
+
+#include <loco.h>
+
+namespace moco
+{
+namespace tf
+{
+
+/**
+ * @brief  Convert TFRelu to Canonical ReLU
+ */
+class ReluCanonicalizer : public Transform
+{
+public:
+  const char *name(void) const final { return "ReluCanonicalizer"; }
+
+public:
+  bool run(loco::Graph *graph) override;
+};
+
+} // namespace tf
+} // namespace moco
+
+#endif // __MOCO_TF_RELU_CANONICALIZER_H__
-- 
2.7.4