1 files changed, 119 insertions, 0 deletions
diff --git a/compiler/enco/core/src/Transforms/DuplicatedObjectReduction.cpp b/compiler/enco/core/src/Transforms/DuplicatedObjectReduction.cpp
new file mode 100644
index 000000000..fa84c005c
--- /dev/null
+++ b/compiler/enco/core/src/Transforms/DuplicatedObjectReduction.cpp
@@ -0,0 +1,119 @@
+/*
+ * Copyright (c) 2018 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 "DuplicatedObjectReduction.h"
+
+#include "CodeIndex.h"
+#include "IRUtils.h"
+
+#include <set>
+
+namespace
+{
+
+/**
+ * @brief Collect feature objects in coco IR
+ */
+std::set<coco::FeatureObject *> features(const coco::Module *m)
+{
+  std::set<coco::FeatureObject *> res;
+
+  for (uint32_t n = 0; n < m->entity()->object()->size(); ++n)
+  {
+    if (auto feature = m->entity()->object()->at(n)->asFeature())
+    {
+      res.insert(feature);
+    }
+  }
+
+  return res;
+}
+
+std::set<coco::FeatureObject *> candidates(const coco::FeatureObject *src)
+{
+  std::set<coco::FeatureObject *> res;
+
+  for (auto consumer : coco::consumers(src))
+  {
+    if (auto copy = consumer->loc()->asCopy())
+    {
+      auto dst = copy->into()->asFeature();
+      assert(dst != nullptr);
+
+      if (dst->layout()->id() == coco::FeatureLayouts::BHWC::uid())
+      {
+        res.insert(dst);
+      }
+    }
+  }
+
+  return res;
+}
+
+CodeIndex code_index(coco::Object::Producer *p)
+{
+  if (auto ins = p->loc())
+  {
+    return ::code_index(ins);
+  }
+
+  return CodeIndex{};
+}
+
+} // namespace
+
+namespace enco
+{
+
+void reduce_duplicated_object(enco::Code *code)
+{
+  auto m = code->module();
+
+  for (const auto &src : features(m))
+  {
+    auto copied = candidates(src);
+
+    if (copied.size() <= 1)
+    {
+      continue;
+    }
+
+    // Find the dominator
+    coco::FeatureObject *dominator = nullptr;
+
+    for (auto candidate : copied)
+    {
+      if (dominator == nullptr)
+      {
+        dominator = candidate;
+      }
+      else if (code_index(coco::producer(candidate)) < code_index(coco::producer(dominator)))
+      {
+        dominator = candidate;
+      }
+    }
+
+    // Replace all the occurunce of dominated objects with its dominator
+    copied.erase(dominator);
+
+    for (auto dominatee : copied)
+    {
+      subst(dominatee, dominator);
+    }
+  }
+}
+
+} // namespace enco