From 4480a441f9273be5c08b524bfa9ffd67734da5ce Mon Sep 17 00:00:00 2001
From: =?utf8?q?=EB=B0=95=EC=A2=85=ED=98=84/=EB=8F=99=EC=9E=91=EC=A0=9C?=
 =?utf8?q?=EC=96=B4Lab=28SR=29/Staff=20Engineer/=EC=82=BC=EC=84=B1?=
 =?utf8?q?=EC=A0=84=EC=9E=90?= <jh1302.park@samsung.com>
Date: Wed, 28 Nov 2018 12:43:49 +0900
Subject: [PATCH] [enco] Delegate Concat to NN runtime (#2426)

With this commit, enco backend delegates ConcatF to NN runtime
instead of lowering it as a sequence of Shuffle.

Signed-off-by: Jonghyun Park <jh1302.park@samsung.com>
---
 contrib/enco/core/src/ANN/IR/Operation.def |  1 +
 contrib/enco/core/src/Backend.cpp          |  4 +--
 contrib/enco/core/src/Transforms/Split.cpp | 56 ++++++++++++++++++++++++++++++
 3 files changed, 59 insertions(+), 2 deletions(-)

diff --git a/contrib/enco/core/src/ANN/IR/Operation.def b/contrib/enco/core/src/ANN/IR/Operation.def
index 56b2e5c..693377e 100644
--- a/contrib/enco/core/src/ANN/IR/Operation.def
+++ b/contrib/enco/core/src/ANN/IR/Operation.def
@@ -12,3 +12,4 @@ ANN_OPERATION(AVG_POOL_2D, ANEURALNETWORKS_AVERAGE_POOL_2D)
 ANN_OPERATION(RELU, ANEURALNETWORKS_RELU)
 ANN_OPERATION(RELU6, ANEURALNETWORKS_RELU6)
 ANN_OPERATION(PAD, ANEURALNETWORKS_PAD)
+ANN_OPERATION(CONCAT, ANEURALNETWORKS_CONCATENATION)
diff --git a/contrib/enco/core/src/Backend.cpp b/contrib/enco/core/src/Backend.cpp
index 245f86c..43feb9d 100644
--- a/contrib/enco/core/src/Backend.cpp
+++ b/contrib/enco/core/src/Backend.cpp
@@ -119,8 +119,8 @@ void BackendImpl::compile(coco::Module *m, coco::Data *d)
 
   // Lower Copy as Shuffle
   lower_copy(code(sess));
-  // Lower ConcatF as Shuffle
-  lower_concat(code(sess));
+  // TODO Lower ConcatF that cannot be delegated to NNAPI as Shuffle
+  // lower_concat(code(sess));
 
   generate_bypass_shuffle(code(sess));
 
diff --git a/contrib/enco/core/src/Transforms/Split.cpp b/contrib/enco/core/src/Transforms/Split.cpp
index 677506d..7be8225 100644
--- a/contrib/enco/core/src/Transforms/Split.cpp
+++ b/contrib/enco/core/src/Transforms/Split.cpp
@@ -110,6 +110,35 @@ private:
   coco::FeatureObject *_out;
 };
 
+/**
+ * WARN The current implementation supports concatenation along depth only
+ */
+class ANNConcatAppender final : public ANNOpAppender
+{
+public:
+  void left(coco::FeatureObject *o) { _left = o; }
+  void right(coco::FeatureObject *o) { _right = o; }
+  void out(coco::FeatureObject *o) { _out = o; }
+
+public:
+  void append(ANNBinder *binder) const override
+  {
+    auto left = binder->addOperand<float>(_left);
+    auto right = binder->addOperand<float>(_right);
+    auto axis = binder->addOperand<int32_t>();
+    binder->setOperand(axis, 3 /* DEPTH */);
+
+    auto out = binder->addOperand<float>(_out);
+
+    binder->addOperation(ann::Operation::Code::CONCAT, {left, right, axis}, {out});
+  }
+
+private:
+  coco::FeatureObject *_left;
+  coco::FeatureObject *_right;
+  coco::FeatureObject *_out;
+};
+
 class ANNConv2DAppender final : public ANNOpAppender
 {
 public:
@@ -759,6 +788,33 @@ public:
         return std::move(app);
       }
     }
+    else if (auto op = eval->op()->asConcatF())
+    {
+      auto left_load = op->left()->asLoad();
+      auto right_load = op->right()->asLoad();
+
+      if (left_load && right_load && (op->axis() == coco::ConcatF::Axis::Depth))
+      {
+        // Let's compile the following code fragment:
+        //
+        //   %ofm = eval(ConcatF(Depth, Load(%left), Load(%right)))
+        //
+        auto left = left_load->object()->asFeature();
+        auto right = right_load->object()->asFeature();
+        assert(left != nullptr && right != nullptr);
+
+        auto out = eval->out()->asFeature();
+        assert(out != nullptr);
+
+        auto app = make_unique<ANNConcatAppender>();
+
+        app->left(left);
+        app->right(right);
+        app->out(out);
+
+        return std::move(app);
+      }
+    }
 
     // Return nullptr if a given Eval instruction is incompatible
     return nullptr;
-- 
2.7.4