From 5475964f0c5d6b25c9fa857060693328801e5b5b Mon Sep 17 00:00:00 2001
From: =?utf8?q?=EC=9C=A4=ED=98=84=EC=8B=9D/On-Device=20Lab=28SR=29/Princip?=
 =?utf8?q?al=20Engineer/=EC=82=BC=EC=84=B1=EC=A0=84=EC=9E=90?=
 <hyunsik.yoon@samsung.com>
Date: Wed, 16 Oct 2019 16:48:10 +0900
Subject: [PATCH] [exo] Introducing FuseReluPass (#8176)

* [exo] Introducing FuseReluPass

This introduces FuseReluPass, which fuse relu/relu6 into 10 TensorFlow Lite ops.
This commit adds code that finds candidate subgraph.

Signed-off-by: Hyun Sik Yoon <hyunsik.yoon@samsung.com>

* remove unused var (to avoid CI error)

* Update compiler/exo/src/Pass/FuseReluPass.h

Co-Authored-By: hyunsik-yoon <hyunsik.yoon@samsung.com>
---
 compiler/exo/src/Pass/FuseReluPass.cpp | 91 ++++++++++++++++++++++++++++++++++
 compiler/exo/src/Pass/FuseReluPass.h   | 40 +++++++++++++++
 2 files changed, 131 insertions(+)
 create mode 100644 compiler/exo/src/Pass/FuseReluPass.cpp
 create mode 100644 compiler/exo/src/Pass/FuseReluPass.h

diff --git a/compiler/exo/src/Pass/FuseReluPass.cpp b/compiler/exo/src/Pass/FuseReluPass.cpp
new file mode 100644
index 0000000..b07e962
--- /dev/null
+++ b/compiler/exo/src/Pass/FuseReluPass.cpp
@@ -0,0 +1,91 @@
+/*
+ * 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 <loco/IR/Nodes.h>
+
+#include <set>
+
+namespace
+{
+
+bool is_pred_fusable(loco::Node *node)
+{
+  using namespace locoex;
+
+  auto add = dynamic_cast<TFLAdd *>(node);
+  auto avgpool = dynamic_cast<TFLAveragePool2D *>(node);
+  auto conv = dynamic_cast<TFLConv2D *>(node);
+  auto maxpool = dynamic_cast<TFLMaxPool2D *>(node);
+  auto mul = dynamic_cast<TFLMul *>(node);
+
+  return (add and add->fusedActivationFunction() == FusedActFunc::NONE) or
+         (avgpool and avgpool->fusedActivationFunction() == FusedActFunc::NONE) or
+         (conv and conv->fusedActivationFunction() == FusedActFunc::NONE) or
+         (maxpool and maxpool->fusedActivationFunction() == FusedActFunc::NONE) or
+         (mul and mul->fusedActivationFunction() == FusedActFunc::NONE);
+  // TODO Consider adding CONCATENATION, DEPTHWISE_CONV_2D, FULLY_CONNECTED,
+  //      TODO L2_NORMALIZATION, TODO L2_POOL_2D
+};
+
+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;
+};
+
+} // 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);
+    }
+  }
+
+  // TODO write code for fusing
+
+  return false;
+}
+
+} // namespace exo
diff --git a/compiler/exo/src/Pass/FuseReluPass.h b/compiler/exo/src/Pass/FuseReluPass.h
new file mode 100644
index 0000000..1cd276b
--- /dev/null
+++ b/compiler/exo/src/Pass/FuseReluPass.h
@@ -0,0 +1,40 @@
+/*
+ * 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 __PASS_FUSE_RELU_PASS_H__
+#define __PASS_FUSE_RELU_PASS_H__
+
+#include <logo/Pass.h>
+
+namespace exo
+{
+
+/**
+ * @brief Class to fuse TFLRelu or TFLRelu6 into the TensorFlow Lite ops below:
+ *
+ *   ADD, AVERAGE_POOL_2D, CONCATENATION, CONV_2D, DEPTHWISE_CONV_2D,
+ *   FULLY_CONNECTED, L2_NORMALIZATION, L2_POOL_2D, MAX_POOL_2D, MUL
+ */
+struct FuseReluPass final : public logo::Pass
+{
+  const char *name(void) const final { return "exo::FuseReluPass"; }
+
+  bool run(loco::Graph *g) final;
+};
+
+} // namespace exo
+
+#endif // __PASS_FUSE_RELU_PASS_H__
-- 
2.7.4