From e44d571e798ccd7528e3a700a1aead85713fc54a Mon Sep 17 00:00:00 2001
From: =?utf8?q?=EB=82=A8=EA=B6=81=EC=84=9D/On-Device=20Lab=28SR=29/Enginee?=
 =?utf8?q?r/=EC=82=BC=EC=84=B1=EC=A0=84=EC=9E=90?= <sk.namkoong@samsung.com>
Date: Fri, 23 Aug 2019 10:02:37 +0900
Subject: [PATCH] [moco-tf] Support TFTanh Canonicalization (#6852)

This commit will enable for supporting `TFTanh` canonicalization

Signed-off-by: Seok NamKoong <sk.namkoong@samsung.com>
---
 .../src/Canonicalization/TanhCanonicalizer.cpp     | 89 ++++++++++++++++++++++
 .../src/Canonicalization/TanhCanonicalizer.h       | 44 +++++++++++
 compiler/moco-tf/src/Canonicalizer.cpp             |  2 +
 3 files changed, 135 insertions(+)
 create mode 100644 compiler/moco-tf/src/Canonicalization/TanhCanonicalizer.cpp
 create mode 100644 compiler/moco-tf/src/Canonicalization/TanhCanonicalizer.h

diff --git a/compiler/moco-tf/src/Canonicalization/TanhCanonicalizer.cpp b/compiler/moco-tf/src/Canonicalization/TanhCanonicalizer.cpp
new file mode 100644
index 0000000..9b7b073
--- /dev/null
+++ b/compiler/moco-tf/src/Canonicalization/TanhCanonicalizer.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 "TanhCanonicalizer.h"
+
+#include "Dialect/TFDialect.h"
+#include "Dialect/TFNodes.h"
+#include "Dialect/TFNodeVisitor.h"
+#include "Dialect/TFNodeImpl.h"
+
+#include <stdex/Memory.h>
+
+namespace
+{
+
+bool canonicalize_tanh(loco::Graph *graph, moco::tf::TFTanh *node)
+{
+  /**
+   * @note This will replace TFTanh node with Canonical Tanh
+   *
+   *       Before
+   *                 A --- TFTanh -- C
+   *       After
+   *                    +- TFTanh --
+   *                    |
+   *                 A -+-- Tanh --- C
+   *
+   *       Where
+   *                 A : x of TFTanh
+   *                 C : a node that uses TFTanh as an input
+   *                 TFTanh is disconnected from C
+   */
+
+  auto tanh_node = graph->nodes()->create<loco::Tanh>();
+
+  auto node_A = node->x();
+
+  // update connections
+  tanh_node->input(node_A);
+
+  // replace node
+  replace(node).with(tanh_node);
+
+  return true;
+}
+
+} // namespace
+
+namespace moco
+{
+namespace tf
+{
+
+bool TanhCanonicalizer::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::TFTanh *>(node);
+      if (tf_node != nullptr)
+      {
+        if (canonicalize_tanh(graph, tf_node))
+          changed = true;
+      }
+    }
+  }
+
+  return changed;
+}
+
+} // namespace tf
+} // namespace moco
diff --git a/compiler/moco-tf/src/Canonicalization/TanhCanonicalizer.h b/compiler/moco-tf/src/Canonicalization/TanhCanonicalizer.h
new file mode 100644
index 0000000..cf566a4
--- /dev/null
+++ b/compiler/moco-tf/src/Canonicalization/TanhCanonicalizer.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_TANH_CANONICALIZER_H__
+#define __MOCO_TF_TANH_CANONICALIZER_H__
+
+#include "Transform.h"
+
+#include <loco.h>
+
+namespace moco
+{
+namespace tf
+{
+
+/**
+ * @brief  Convert TFTanh to Canonical Tanh
+ */
+class TanhCanonicalizer : public Transform
+{
+public:
+  const char *name(void) const final { return "TanhCanonicalizer"; }
+
+public:
+  bool run(loco::Graph *graph) override;
+};
+
+} // namespace tf
+} // namespace moco
+
+#endif // __MOCO_TF_TANH_CANONICALIZER_H__
diff --git a/compiler/moco-tf/src/Canonicalizer.cpp b/compiler/moco-tf/src/Canonicalizer.cpp
index cc4dc61..3a0989d 100644
--- a/compiler/moco-tf/src/Canonicalizer.cpp
+++ b/compiler/moco-tf/src/Canonicalizer.cpp
@@ -44,6 +44,7 @@
 #include "Canonicalization/SqueezeCanonicalizer.h"
 #include "Canonicalization/StopGradientCanonicalizer.h"
 #include "Canonicalization/SubCanonicalizer.h"
+#include "Canonicalization/TanhCanonicalizer.h"
 
 #include "Dialect/TFDialect.h"
 #include "Dialect/TFNodes.h"
@@ -108,6 +109,7 @@ void Canonicalizer::canonicalize(loco::Graph *g) const
   phase.emplace_back(stdex::make_unique<SqueezeCanonicalizer>());
   phase.emplace_back(stdex::make_unique<StopGradientCanonicalizer>());
   phase.emplace_back(stdex::make_unique<SubCanonicalizer>());
+  phase.emplace_back(stdex::make_unique<TanhCanonicalizer>());
   /* TRANSFORM DECLARATION END */
 
   moco::tf::PhaseRunner<moco::tf::PhaseStrategy::Restart> phase_runner{g};
-- 
2.7.4