Rename contrib as compiler (#4342)

* Rename contrib as compiler

This commit renames the top-level contrib directory as "compiler".

Signed-off-by: Jonghyun Park <jh1302.park@samsung.com>

* Fix CMakeLists.txt

77 files changed, 3278 insertions, 0 deletions

diff --git a/compiler/nest/.FORMATCHECKED b/compiler/nest/.FORMATCHECKED
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/compiler/nest/.FORMATCHECKED
diff --git a/compiler/nest/CMakeLists.txt b/compiler/nest/CMakeLists.txt
new file mode 100644
index 000000000..ad6d4787c
--- /dev/null
+++ b/compiler/nest/CMakeLists.txt
@@ -0,0 +1 @@
+add_subdirectory(core)
diff --git a/compiler/nest/README.md b/compiler/nest/README.md
new file mode 100644
index 000000000..64cfb75ed
--- /dev/null
+++ b/compiler/nest/README.md
@@ -0,0 +1,8 @@
+# nest
+
+_nest_ is a lightweight nested loop generation library, which makes it easy to generate complex,
+optimized nested loops (such as loops in conv2d).
+
+## References
+- [Halide](https://github.com/halide/Halide)
+- [Tensor Comprehension](https://github.com/facebookresearch/TensorComprehensions)
diff --git a/compiler/nest/core/CMakeLists.txt b/compiler/nest/core/CMakeLists.txt
new file mode 100644
index 000000000..b6754b081
--- /dev/null
+++ b/compiler/nest/core/CMakeLists.txt
@@ -0,0 +1,27 @@
+file(GLOB_RECURSE SOURCES "src/*.cpp")
+file(GLOB_RECURSE TESTS "src/*.test.cpp")
+list(REMOVE_ITEM SOURCES ${TESTS})
+
+add_library(nest_core STATIC ${SOURCES})
+set_target_properties(nest_core PROPERTIES POSITION_INDEPENDENT_CODE ON)
+target_include_directories(nest_core PUBLIC include)
+
+file(GLOB EXAMPLE_FILES "examples/*.cpp")
+
+foreach(EXAMPLE_FILE IN ITEMS ${EXAMPLE_FILES})
+   get_filename_component(EXAMPLE_NAME ${EXAMPLE_FILE} NAME_WE)
+   set(TARGET_NAME nest_IR_example_${EXAMPLE_NAME})
+   add_executable(${TARGET_NAME} ${EXAMPLE_FILE})
+   target_link_libraries(${TARGET_NAME} nest_core)
+endforeach(EXAMPLE_FILE)
+
+nncc_find_package(GTest QUIET)
+
+if(NOT GTest_FOUND)
+  return()
+endif(NOT GTest_FOUND)
+
+add_executable(nest_core_test ${TESTS})
+target_link_libraries(nest_core_test gtest_main)
+target_link_libraries(nest_core_test nest_core)
+add_test(nest_core_test nest_core_test)
diff --git a/compiler/nest/core/examples/conv2d.cpp b/compiler/nest/core/examples/conv2d.cpp
new file mode 100644
index 000000000..e405af9c0
--- /dev/null
+++ b/compiler/nest/core/examples/conv2d.cpp
@@ -0,0 +1,152 @@
+/*
+ * 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 <nest/Module.h>
+
+int main(int, char **)
+{
+  // This example shows how to specify convolution with IFM(1x3x3) and Kernel(1x1x3x3) with nest
+  // - STRIDE is 1, and there is no padding
+  //
+  // The below code corresponds to the following nest DSL code:
+  // ----------------------------------------------------------------------------------------------
+  // Domain ofm(1, 1, 1)
+  // Domain ifm(1, 3, 3)
+  // Domain ker(1, 1, 3, 3)
+  //
+  // Var ofm_ch  : { min = 0, max = 1 }
+  // Var ofm_row : { min = 0, max = 1 }
+  // Var ofm_col : { min = 0, max = 1 }
+  // Var ker_ch  : { min = 0, max = 1 }
+  // Var ker_row : { min = 0, max = 3 }
+  // Var ker_col : { min = 0, max = 3 }
+  //
+  // PUSH ifm(ker_ch, ker_row, ker_col) * ker(ofm_ch, ker_ch, ofm_row + ker_row, ofm_col + ker_col)
+  // RET  ofm(ofm_ch, ofm_row, ofm_col)
+  // ----------------------------------------------------------------------------------------------
+  //
+  // The first part declares Domain(s) which corresponds to a multi-dimensional array in C-style
+  // (without type). For example, 'Domain ofm(1, 3, 3)' corresponds to the
+  // following C array declaration.
+  //   float ofm[1][3][3];
+  // (Here we assume that domain type is 'float')
+  //
+  // The second part declares Var(s) which serves as a loop iteration variable. Basically, each
+  // variable emits one for loop and these loops are nested. As there are 6 variables in the above
+  // example, there will be 6 nested-loops.
+  //
+  // Each variable has a corresponding bound, and the bound of each variable states the starting /
+  // termination condition. For example, 'Var ofm_ch : { min = 0, max = 1 }' will introduce the
+  // following for loop:
+  // ----------------------------------------------------------------------------------------------
+  //   for (int ofm_ch = 0; ofm_ch < 1; ++ofm_ch) { ... }
+  // ----------------------------------------------------------------------------------------------
+  //
+  // The last part declares statement(s) which state the computation performed inside these nested
+  // loops. Nest is stack-based. There is a virtual stack inside nested loop, and the evaluation of
+  // each statement will update this stack.
+  //
+  // Each nest code has one return statement (RET). This return statement specifies where to write
+  // the computed result.
+  //
+  // PUSH 'expr' statement evaluates an arithmetic expression (specified by 'expr') and pushes the
+  // numeric result to the stack. When PUSH statement evaluates an arithmetic expression, variables
+  // that do not appear in RET statement are treated as reduction variables. For example,
+  // ker_ch, ker_row, and ker_col do not appear in RET statement. So, PUSH '...' statement in the
+  // above example corresponds to the following nested loops:
+  // ----------------------------------------------------------------------------------------------
+  // float value = 0.0f;
+  //
+  // for (int ker_ch = 0; ker_ch < 1; ++ker_ch) {
+  //   for (int ker_row = 0; ker_row < 3; ++ker_row) {
+  //     for (int ker_col = 0; ker_col < 3; ++ker_col) {
+  //       float ifm_value = ifm[ker_ch][ofm_row + ker_row][ofm_col + ker_col];
+  //       float ker_value = ker[ofm_ch][ker_ch][ker_row][ker_col];
+  //       value += ifm_value * ker_value;
+  //    }
+  //  }
+  // }
+  // ----------------------------------------------------------------------------------------------
+  //
+  // In summary, the above nest example corresponds to the following 2D convolution:
+  // ----------------------------------------------------------------------------------------------
+  // float ofm[1][1][1];
+  // float ifm[1][3][3];
+  // float ker[1][1][3][3];
+  //
+  // for (int ofm_ch = 0; ofm_ch < 1; ++ofm_ch) {
+  //   for (int ofm_row = 0; ofm_row < 1; ++ofm_row) {
+  //     for (int ofm_col = 0; ofm_col < 1; ++ofm_col) {
+  //       float value = 0.0f;
+  //
+  //       for (int ker_ch = 0; ker_ch < 1; ++ker_ch) {
+  //         for (int ker_row = 0; ker_row < 3; ++ker_row) {
+  //           for (int ker_col = 0; ker_col < 3; ++ker_col) {
+  //             float ifm_value = ifm[ker_ch][ofm_row + ker_row][ofm_col + ker_col];
+  //             float ker_value = ker[ofm_ch][ker_ch][ker_row][ker_col];
+  //             value += ifm_value * ker_value;
+  //           }
+  //         }
+  //       }
+  //
+  //       ofm[ofm_ch][ofm_col][ofm_row] = value;
+  //     }
+  //   }
+  // }
+  // ----------------------------------------------------------------------------------------------
+  //
+  nest::Module m;
+
+  //
+  // Domains
+  //
+  auto ofm = m.domain().make({1 /*C*/, 1 /*H*/, 1 /*W*/});
+  auto ifm = m.domain().make({1 /*C*/, 3 /*H*/, 3 /*W*/});
+  auto ker = m.domain().make({1 /*N*/, 1 /*C*/, 3 /*H*/, 3 /*W*/});
+
+  //
+  // Variables
+  //
+  auto ofm_ch = m.var().make();
+  auto ofm_row = m.var().make();
+  auto ofm_col = m.var().make();
+
+  auto ker_ch = m.var().make();
+  auto ker_row = m.var().make();
+  auto ker_col = m.var().make();
+
+  // Declare the bound of each variables
+  using nest::Bound;
+
+  m.var().bound(ofm_ch) = Bound{0, 1};
+  m.var().bound(ofm_row) = Bound{0, 1};
+  m.var().bound(ofm_col) = Bound{0, 1};
+
+  m.var().bound(ker_ch) = Bound{0, 1};
+  m.var().bound(ker_row) = Bound{0, 3};
+  m.var().bound(ker_col) = Bound{0, 3};
+
+  //
+  // Statement
+  //
+  auto ifm_value = ifm(ker_ch, ofm_row + ker_row, ofm_col + ker_col);
+  auto ker_value = ker(ofm_ch, ker_ch, ker_row, ker_col);
+
+  m.push(ifm_value * ker_value);
+  m.ret(ofm(ofm_ch, ofm_row, ofm_col));
+
+  return 0;
+}
diff --git a/compiler/nest/core/include/nest/Block.h b/compiler/nest/core/include/nest/Block.h
new file mode 100644
index 000000000..e9b646f4e
--- /dev/null
+++ b/compiler/nest/core/include/nest/Block.h
@@ -0,0 +1,46 @@
+/*
+ * 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.
+ */
+
+#ifndef __NEST_BLOCK_H__
+#define __NEST_BLOCK_H__
+
+#include "nest/Stmt.h"
+
+#include <vector>
+
+#include <cstdint>
+
+namespace nest
+{
+
+struct Block
+{
+public:
+  uint32_t size(void) const { return _stmts.size(); }
+
+public:
+  const Stmt &at(uint32_t n) const { return _stmts.at(n); }
+
+public:
+  void append(const Stmt &stmt) { _stmts.emplace_back(stmt); }
+
+private:
+  std::vector<Stmt> _stmts;
+};
+
+} // namespace nest
+
+#endif // __NEST_BLOCK_H__
diff --git a/compiler/nest/core/include/nest/Bound.h b/compiler/nest/core/include/nest/Bound.h
new file mode 100644
index 000000000..252a69e85
--- /dev/null
+++ b/compiler/nest/core/include/nest/Bound.h
@@ -0,0 +1,47 @@
+/*
+ * 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.
+ */
+
+#ifndef __NEST_BOUND_H__
+#define __NEST_BOUND_H__
+
+#include <cstdint>
+
+namespace nest
+{
+
+class Bound
+{
+public:
+  Bound() = default;
+
+public:
+  Bound(int64_t min, int64_t max) : _min{min}, _max{max}
+  {
+    // DO NOTHING
+  }
+
+public:
+  int64_t min(void) const { return _min; }
+  int64_t max(void) const { return _max; }
+
+private:
+  int64_t _min;
+  int64_t _max;
+};
+
+} // namespace nest
+
+#endif // __NEST_BOUND_H__
diff --git a/compiler/nest/core/include/nest/Closure.h b/compiler/nest/core/include/nest/Closure.h
new file mode 100644
index 000000000..7e09afa1a
--- /dev/null
+++ b/compiler/nest/core/include/nest/Closure.h
@@ -0,0 +1,49 @@
+/*
+ * 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.
+ */
+
+#ifndef __NEST_CLOSURE_H__
+#define __NEST_CLOSURE_H__
+
+#include "nest/DomainID.h"
+#include "nest/Expr.h"
+
+namespace nest
+{
+
+class Closure
+{
+public:
+  template <typename... Args>
+  Closure(const DomainID &id, Args &&... indices) : _id{id}, _sub{std::forward<Args>(indices)...}
+  {
+    // DO NOTHING
+  }
+
+public:
+  operator Expr() const;
+
+public:
+  const DomainID &id(void) const { return _id; }
+  const expr::Subscript &sub(void) const { return _sub; }
+
+private:
+  DomainID const _id;
+  expr::Subscript const _sub;
+};
+
+} // namespace nest
+
+#endif // __NEST_CLOSURE_H__
diff --git a/compiler/nest/core/include/nest/Domain.h b/compiler/nest/core/include/nest/Domain.h
new file mode 100644
index 000000000..8d809e2ad
--- /dev/null
+++ b/compiler/nest/core/include/nest/Domain.h
@@ -0,0 +1,54 @@
+/*
+ * 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.
+ */
+
+#ifndef __NEST_DOMAIN_H__
+#define __NEST_DOMAIN_H__
+
+#include "nest/Closure.h"
+
+namespace nest
+{
+
+class Domain
+{
+public:
+  Domain() = default;
+
+public:
+  Domain(const DomainID &id) : _id{id}
+  {
+    // DO NOTHING
+  }
+
+public:
+  Domain(const Domain &) = default;
+
+public:
+  template <typename... Args> Closure operator()(Args &&... indices)
+  {
+    return Closure{_id, std::forward<Args>(indices)...};
+  }
+
+public:
+  const DomainID &id(void) const { return _id; }
+
+private:
+  DomainID const _id;
+};
+
+} // namespace nest
+
+#endif // __NEST_DOMAIN_H__
diff --git a/compiler/nest/core/include/nest/DomainContext.h b/compiler/nest/core/include/nest/DomainContext.h
new file mode 100644
index 000000000..425accb93
--- /dev/null
+++ b/compiler/nest/core/include/nest/DomainContext.h
@@ -0,0 +1,45 @@
+/*
+ * 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.
+ */
+
+#ifndef __NEST_DOMAIN_CONTEXT_H__
+#define __NEST_DOMAIN_CONTEXT_H__
+
+#include "nest/DomainInfo.h"
+#include "nest/Domain.h"
+
+#include <vector>
+
+namespace nest
+{
+
+class DomainContext
+{
+public:
+  uint32_t count(void) const;
+
+public:
+  Domain make(std::initializer_list<uint32_t> dims);
+
+public:
+  const DomainInfo &info(const Domain &) const;
+
+private:
+  std::vector<DomainInfo> _info;
+};
+
+} // namespace nest
+
+#endif // __NEST_DOMAIN_CONTEXT_H__
diff --git a/compiler/nest/core/include/nest/DomainID.h b/compiler/nest/core/include/nest/DomainID.h
new file mode 100644
index 000000000..935680f58
--- /dev/null
+++ b/compiler/nest/core/include/nest/DomainID.h
@@ -0,0 +1,54 @@
+/*
+ * 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.
+ */
+
+#ifndef __NEST_DOMAIN_ID_H__
+#define __NEST_DOMAIN_ID_H__
+
+#include <cstdint>
+
+namespace nest
+{
+
+class DomainID
+{
+public:
+  DomainID();
+
+public:
+  explicit DomainID(uint32_t value) : _value{value}
+  {
+    // DO NOTHING
+  }
+
+public:
+  DomainID(const DomainID &vid) : _value{vid._value}
+  {
+    // DO NOTHING
+  }
+
+public:
+  uint32_t value(void) const { return _value; }
+
+private:
+  uint32_t _value;
+};
+
+bool operator==(const DomainID &lhs, const DomainID &rhs);
+bool operator<(const DomainID &lhs, const DomainID &rhs);
+
+} // namespace nest
+
+#endif // __NEST_DOMAIN_ID_H__
diff --git a/compiler/nest/core/include/nest/DomainInfo.h b/compiler/nest/core/include/nest/DomainInfo.h
new file mode 100644
index 000000000..ac8f04e8f
--- /dev/null
+++ b/compiler/nest/core/include/nest/DomainInfo.h
@@ -0,0 +1,48 @@
+/*
+ * 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.
+ */
+
+#ifndef __NEST_DOMAIN_INFO_H__
+#define __NEST_DOMAIN_INFO_H__
+
+#include <initializer_list>
+#include <vector>
+
+#include <cstdint>
+
+namespace nest
+{
+
+class DomainInfo
+{
+public:
+  DomainInfo(std::initializer_list<uint32_t> dims) : _dims{dims}
+  {
+    // DO NOTHING
+  }
+
+public:
+  uint32_t rank(void) const { return _dims.size(); }
+
+public:
+  uint32_t dim(uint32_t axis) const { return _dims.at(axis); }
+
+private:
+  std::vector<uint32_t> _dims;
+};
+
+} // namespace nest
+
+#endif // __NEST_DOMAIN_INFO_H__
diff --git a/compiler/nest/core/include/nest/Expr.h b/compiler/nest/core/include/nest/Expr.h
new file mode 100644
index 000000000..520edcd30
--- /dev/null
+++ b/compiler/nest/core/include/nest/Expr.h
@@ -0,0 +1,44 @@
+/*
+ * 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.
+ */
+
+#ifndef __NEST_EXPR_H__
+#define __NEST_EXPR_H__
+
+#include "nest/expr/Node.h"
+#include "nest/expr/Visitor.h"
+
+#include "nest/expr/VarNode.h"
+#include "nest/expr/DerefNode.h"
+#include "nest/expr/AddNode.h"
+#include "nest/expr/MulNode.h"
+
+#include <memory>
+
+namespace nest
+{
+
+// WARNING All of the descendant of expr::Node SHOULD BE immutable
+//
+// The copy/move constructor of Block and Module class simply copies their shared pointer under
+// the assumption that these classes are immutable.
+using Expr = std::shared_ptr<nest::expr::Node>;
+
+} // namespace nest
+
+nest::Expr operator+(const nest::Expr &, const nest::Expr &);
+nest::Expr operator*(const nest::Expr &, const nest::Expr &);
+
+#endif // __NEST_EXPR_H__
diff --git a/compiler/nest/core/include/nest/FV.h b/compiler/nest/core/include/nest/FV.h
new file mode 100644
index 000000000..089f1596b
--- /dev/null
+++ b/compiler/nest/core/include/nest/FV.h
@@ -0,0 +1,39 @@
+/*
+ * 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.
+ */
+
+#ifndef __NEST_FV_H__
+#define __NEST_FV_H__
+
+#include "nest/VarID.h"
+
+#include "nest/Expr.h"
+
+#include <set>
+
+namespace nest
+{
+
+/**
+ * @brief Collect free variables from nest expr/stmt/block/...
+ */
+struct FV
+{
+  static std::set<VarID> in(const Expr &);
+};
+
+} // namespace nest
+
+#endif // __NEST_FV_H__
diff --git a/compiler/nest/core/include/nest/Level.h b/compiler/nest/core/include/nest/Level.h
new file mode 100644
index 000000000..ac1788636
--- /dev/null
+++ b/compiler/nest/core/include/nest/Level.h
@@ -0,0 +1,45 @@
+/*
+ * 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.
+ */
+
+#ifndef __NEST_LEVEL_H__
+#define __NEST_LEVEL_H__
+
+#include <cstdint>
+
+namespace nest
+{
+class Level final
+{
+public:
+  Level();
+  explicit Level(uint32_t value);
+
+public:
+  bool valid(void) const;
+
+public:
+  uint32_t value(void) const { return _value; }
+
+private:
+  uint32_t _value;
+};
+
+bool operator==(const Level &lhs, const Level &rhs);
+bool operator<(const Level &lhs, const Level &rhs);
+
+} // namespace nest
+
+#endif // __NEST_LEVEL_H__
diff --git a/compiler/nest/core/include/nest/Module.h b/compiler/nest/core/include/nest/Module.h
new file mode 100644
index 000000000..1294e3089
--- /dev/null
+++ b/compiler/nest/core/include/nest/Module.h
@@ -0,0 +1,70 @@
+/*
+ * 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.
+ */
+
+#ifndef __NEST_MODULE_H__
+#define __NEST_MODULE_H__
+
+#include "nest/VarContext.h"
+#include "nest/DomainContext.h"
+#include "nest/Ret.h"
+#include "nest/Block.h"
+
+namespace nest
+{
+
+class Module
+{
+public:
+  Module() = default;
+
+private:
+  VarContext _var_ctx;
+
+public:
+  VarContext &var(void) { return _var_ctx; }
+  const VarContext &var(void) const { return _var_ctx; }
+
+private:
+  DomainContext _domain_ctx;
+
+public:
+  DomainContext &domain(void) { return _domain_ctx; }
+  const DomainContext &domain(void) const { return _domain_ctx; }
+
+private:
+  Block _block;
+
+public:
+  const Block &block(void) const { return _block; }
+
+public:
+  void push(const Expr &expr);
+
+private:
+  std::shared_ptr<Ret> _ret;
+
+public:
+  // NOTE Do NOT invoke ret() before ret(expr) call
+  const Ret &ret(void) const;
+
+public:
+  // NOTE Only one ret(expr) call is allowed for each module
+  void ret(const Closure &closure);
+};
+
+} // namespace nest
+
+#endif // __NEST_MODULE_H__
diff --git a/compiler/nest/core/include/nest/Ret.h b/compiler/nest/core/include/nest/Ret.h
new file mode 100644
index 000000000..8f8af15e2
--- /dev/null
+++ b/compiler/nest/core/include/nest/Ret.h
@@ -0,0 +1,49 @@
+/*
+ * 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.
+ */
+
+#ifndef __NEST_RET_H__
+#define __NEST_RET_H__
+
+#include "nest/DomainID.h"
+#include "nest/Expr.h"
+
+namespace nest
+{
+
+// WARNING Ret SHOULD BE immutable
+//
+// The copy/move constructor of Module class simply copies the shared pointer under the assumption
+// that Ret is immutable.
+class Ret
+{
+public:
+  Ret(const DomainID &id, const expr::Subscript &sub) : _id{id}, _sub{sub}
+  {
+    // DO NOTHING
+  }
+
+public:
+  const DomainID &id(void) const { return _id; }
+  const expr::Subscript &sub(void) const { return _sub; }
+
+private:
+  DomainID _id;
+  expr::Subscript _sub;
+};
+
+} // namespace nest
+
+#endif // __NEST_RET_H__
diff --git a/compiler/nest/core/include/nest/Schedule.h b/compiler/nest/core/include/nest/Schedule.h
new file mode 100644
index 000000000..a92c245c3
--- /dev/null
+++ b/compiler/nest/core/include/nest/Schedule.h
@@ -0,0 +1,52 @@
+/*
+ * 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.
+ */
+
+#ifndef __NEST_SCHEDULE_H__
+#define __NEST_SCHEDULE_H__
+
+#include "nest/Module.h"
+#include "nest/Level.h"
+
+#include <vector>
+
+namespace nest
+{
+
+class Schedule final
+{
+public:
+  explicit Schedule(const Module &);
+
+public:
+  const VarContext &var(void) const { return _module.var(); }
+  const DomainContext &domain(void) const { return _module.domain(); }
+  const Block &block(void) const { return _module.block(); }
+  const Ret &ret(void) const { return _module.ret(); }
+
+public:
+  Var at(const Level &) const;
+  Level level(const Var &) const;
+
+private:
+  Module _module;
+
+private:
+  std::vector<VarID> _level;
+};
+
+} // namespace nest
+
+#endif // __NEST_SCHEDULE_H___
diff --git a/compiler/nest/core/include/nest/Stmt.h b/compiler/nest/core/include/nest/Stmt.h
new file mode 100644
index 000000000..4fff26ffa
--- /dev/null
+++ b/compiler/nest/core/include/nest/Stmt.h
@@ -0,0 +1,34 @@
+/*
+ * 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.
+ */
+
+#ifndef __NEST_STMT_H__
+#define __NEST_STMT_H__
+
+#include "nest/stmt/Node.h"
+#include "nest/stmt/Visitor.h"
+
+#include "nest/stmt/PushNode.h"
+
+#include <memory>
+
+namespace nest
+{
+
+using Stmt = std::shared_ptr<stmt::Node>;
+
+} // namespace nest
+
+#endif // __NEST_STMT_H__
diff --git a/compiler/nest/core/include/nest/Var.h b/compiler/nest/core/include/nest/Var.h
new file mode 100644
index 000000000..bb2c6c786
--- /dev/null
+++ b/compiler/nest/core/include/nest/Var.h
@@ -0,0 +1,49 @@
+/*
+ * 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.
+ */
+
+#ifndef __NEST_VAR_H__
+#define __NEST_VAR_H__
+
+#include "nest/VarID.h"
+#include "nest/Expr.h"
+
+namespace nest
+{
+
+class Var
+{
+public:
+  Var() = default;
+
+public:
+  Var(const VarID &id) : _id{id}
+  {
+    // DO NOTHING
+  }
+
+public:
+  const VarID &id(void) const { return _id; }
+
+public:
+  operator Expr(void) const;
+
+private:
+  VarID const _id;
+};
+
+} // namespace nest
+
+#endif // __NEST_VAR_H__
diff --git a/compiler/nest/core/include/nest/VarContext.h b/compiler/nest/core/include/nest/VarContext.h
new file mode 100644
index 000000000..2438abfce
--- /dev/null
+++ b/compiler/nest/core/include/nest/VarContext.h
@@ -0,0 +1,46 @@
+/*
+ * 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.
+ */
+
+#ifndef __NEST_VAR_CONTEXT_H__
+#define __NEST_VAR_CONTEXT_H__
+
+#include "nest/Bound.h"
+#include "nest/Var.h"
+
+#include <vector>
+
+namespace nest
+{
+
+class VarContext
+{
+public:
+  uint32_t count(void) const;
+
+public:
+  Var make(void);
+
+public:
+  Bound &bound(const Var &);
+  const Bound &bound(const Var &) const;
+
+private:
+  std::vector<Bound> _bound;
+};
+
+} // namespace nest
+
+#endif // __NEST_VAR_CONTEXT_H__
diff --git a/compiler/nest/core/include/nest/VarID.h b/compiler/nest/core/include/nest/VarID.h
new file mode 100644
index 000000000..daf3e9ee4
--- /dev/null
+++ b/compiler/nest/core/include/nest/VarID.h
@@ -0,0 +1,54 @@
+/*
+ * 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.
+ */
+
+#ifndef __NEST_VAR_ID_H__
+#define __NEST_VAR_ID_H__
+
+#include <cstdint>
+
+namespace nest
+{
+
+class VarID
+{
+public:
+  VarID();
+
+public:
+  explicit VarID(uint32_t value) : _value{value}
+  {
+    // DO NOTHING
+  }
+
+public:
+  VarID(const VarID &vid) : _value{vid._value}
+  {
+    // DO NOTHING
+  }
+
+public:
+  uint32_t value(void) const { return _value; }
+
+private:
+  uint32_t _value;
+};
+
+bool operator==(const VarID &lhs, const VarID &rhs);
+bool operator<(const VarID &lhs, const VarID &rhs);
+
+} // namespace nest
+
+#endif // __NEST_VAR_ID_H__
diff --git a/compiler/nest/core/include/nest/expr/AddNode.h b/compiler/nest/core/include/nest/expr/AddNode.h
new file mode 100644
index 000000000..b9b5afb22
--- /dev/null
+++ b/compiler/nest/core/include/nest/expr/AddNode.h
@@ -0,0 +1,53 @@
+/*
+ * 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.
+ */
+
+#ifndef __NEST_EXPR_ADD_NODE_H__
+#define __NEST_EXPR_ADD_NODE_H__
+
+#include "nest/expr/Node.h"
+
+#include <memory>
+
+namespace nest
+{
+namespace expr
+{
+
+class AddNode final : public Node
+{
+public:
+  AddNode(const std::shared_ptr<expr::Node> &lhs, const std::shared_ptr<expr::Node> &rhs)
+      : _lhs{lhs}, _rhs{rhs}
+  {
+    // DO NOTHING
+  }
+
+public:
+  const AddNode *asAdd(void) const override { return this; }
+
+public:
+  const std::shared_ptr<expr::Node> &lhs(void) const { return _lhs; }
+  const std::shared_ptr<expr::Node> &rhs(void) const { return _rhs; }
+
+private:
+  std::shared_ptr<expr::Node> const _lhs;
+  std::shared_ptr<expr::Node> const _rhs;
+};
+
+} // namespace expr
+} // namespace nest
+
+#endif // __NEST_EXPR_ADD_NODE_H__
diff --git a/compiler/nest/core/include/nest/expr/DerefNode.h b/compiler/nest/core/include/nest/expr/DerefNode.h
new file mode 100644
index 000000000..19adfe3b3
--- /dev/null
+++ b/compiler/nest/core/include/nest/expr/DerefNode.h
@@ -0,0 +1,54 @@
+/*
+ * 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.
+ */
+
+#ifndef __NEXT_EXPR_DEREF_NODE_H__
+#define __NEXT_EXPR_DEREF_NODE_H__
+
+#include "nest/DomainID.h"
+
+#include "nest/expr/Subscript.h"
+
+namespace nest
+{
+namespace expr
+{
+
+class DerefNode final : public Node
+{
+public:
+  template <typename... Args>
+  DerefNode(const DomainID &id, Args &&... indicies)
+      : _id{id}, _sub{std::forward<Args>(indicies)...}
+  {
+    // DO NOTHING
+  }
+
+public:
+  const DerefNode *asDeref(void) const override { return this; }
+
+public:
+  const DomainID &id(void) const { return _id; }
+  const Subscript &sub(void) const { return _sub; }
+
+private:
+  DomainID const _id;
+  Subscript const _sub;
+};
+
+} // namespace expr
+} // namespace nest
+
+#endif // __NEXT_EXPR_DEREF_NODE_H__
diff --git a/compiler/nest/core/include/nest/expr/Forward.h b/compiler/nest/core/include/nest/expr/Forward.h
new file mode 100644
index 000000000..ae15b13b4
--- /dev/null
+++ b/compiler/nest/core/include/nest/expr/Forward.h
@@ -0,0 +1,34 @@
+/*
+ * 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.
+ */
+
+#ifndef __NEST_EXPR_FORWARD_H__
+#define __NEST_EXPR_FORWARD_H__
+
+#include "nest/expr/Macro.h"
+
+namespace nest
+{
+namespace expr
+{
+
+#define EXPR(Tag) class NEST_EXPR_CLASS_NAME(Tag);
+#include "nest/expr/Node.def"
+#undef EXPR
+
+} // namespace expr
+} // namespace nest
+
+#endif // __NEST_EXPR_FORWARD_H__
diff --git a/compiler/nest/core/include/nest/expr/Macro.h b/compiler/nest/core/include/nest/expr/Macro.h
new file mode 100644
index 000000000..dca8bd344
--- /dev/null
+++ b/compiler/nest/core/include/nest/expr/Macro.h
@@ -0,0 +1,28 @@
+/*
+ * 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.
+ */
+
+#ifndef __NEST_EXPR_MACRO_H__
+#define __NEST_EXPR_MACRO_H__
+
+#ifndef NEST_EXPR_CLASS_NAME
+#define NEST_EXPR_CLASS_NAME(Tag) Tag##Node
+#endif // NEST_EXPR_CLASS_NAME
+
+#ifndef NEST_EXPR_CAST_METHOD_NAME
+#define NEST_EXPR_CAST_METHOD_NAME(Tag) as##Tag
+#endif // NEST_EXPR_CAST_METHOD_NAME
+
+#endif // __NEST_EXPR_MACRO_H__
diff --git a/compiler/nest/core/include/nest/expr/MulNode.h b/compiler/nest/core/include/nest/expr/MulNode.h
new file mode 100644
index 000000000..f388b33a3
--- /dev/null
+++ b/compiler/nest/core/include/nest/expr/MulNode.h
@@ -0,0 +1,53 @@
+/*
+ * 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.
+ */
+
+#ifndef __NEST_EXPR_MUL_NODE_H__
+#define __NEST_EXPR_MUL_NODE_H__
+
+#include "nest/expr/Node.h"
+
+#include <memory>
+
+namespace nest
+{
+namespace expr
+{
+
+class MulNode final : public Node
+{
+public:
+  MulNode(const std::shared_ptr<expr::Node> &lhs, const std::shared_ptr<expr::Node> &rhs)
+      : _lhs{lhs}, _rhs{rhs}
+  {
+    // DO NOTHING
+  }
+
+public:
+  const MulNode *asMul(void) const override { return this; }
+
+public:
+  const std::shared_ptr<expr::Node> &lhs(void) const { return _lhs; }
+  const std::shared_ptr<expr::Node> &rhs(void) const { return _rhs; }
+
+private:
+  std::shared_ptr<expr::Node> const _lhs;
+  std::shared_ptr<expr::Node> const _rhs;
+};
+
+} // namespace expr
+} // namespace nest
+
+#endif // __NEST_EXPR_MUL_NODE_H__
diff --git a/compiler/nest/core/include/nest/expr/Node.def b/compiler/nest/core/include/nest/expr/Node.def
new file mode 100644
index 000000000..0429517a0
--- /dev/null
+++ b/compiler/nest/core/include/nest/expr/Node.def
@@ -0,0 +1,9 @@
+#ifndef EXPR
+#error EXPR is should be defined before include this file
+#endif
+
+// EXPR(Tag)
+EXPR(Var)
+EXPR(Deref)
+EXPR(Add)
+EXPR(Mul)
diff --git a/compiler/nest/core/include/nest/expr/Node.h b/compiler/nest/core/include/nest/expr/Node.h
new file mode 100644
index 000000000..d187c25fa
--- /dev/null
+++ b/compiler/nest/core/include/nest/expr/Node.h
@@ -0,0 +1,62 @@
+/*
+ * 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.
+ */
+
+#ifndef __NEST_EXPR_NODE_H__
+#define __NEST_EXPR_NODE_H__
+
+#include "nest/expr/Macro.h"
+#include "nest/expr/Forward.h"
+#include "nest/expr/Visitor.h"
+
+#include <stdexcept>
+
+namespace nest
+{
+namespace expr
+{
+
+struct Node
+{
+  virtual ~Node() = default;
+
+#define EXPR(Tag)                                                                       \
+  virtual const NEST_EXPR_CLASS_NAME(Tag) * NEST_EXPR_CAST_METHOD_NAME(Tag)(void) const \
+  {                                                                                     \
+    return nullptr;                                                                     \
+  }
+#include "nest/expr/Node.def"
+#undef EXPR
+
+  template <typename T> T accept(Visitor<T> *v)
+  {
+#define EXPR(Tag)                                 \
+  if (auto e = NEST_EXPR_CAST_METHOD_NAME(Tag)()) \
+  {                                               \
+    return v->visit(e);                           \
+  }
+#include "nest/expr/Node.def"
+#undef EXPR
+
+    throw std::runtime_error{"unreachable"};
+  }
+
+  template <typename T> T accept(Visitor<T> &v) { return accept(&v); }
+};
+
+} // namespace expr
+} // namespace nest
+
+#endif // __NEST_EXPR_NODE_H__
diff --git a/compiler/nest/core/include/nest/expr/Subscript.h b/compiler/nest/core/include/nest/expr/Subscript.h
new file mode 100644
index 000000000..1670b8094
--- /dev/null
+++ b/compiler/nest/core/include/nest/expr/Subscript.h
@@ -0,0 +1,53 @@
+/*
+ * 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.
+ */
+
+#ifndef __NEST_SUBSCRIPT_H__
+#define __NEST_SUBSCRIPT_H__
+
+#include "nest/expr/Node.h"
+
+#include <vector>
+#include <initializer_list>
+
+#include <memory>
+
+namespace nest
+{
+namespace expr
+{
+
+class Subscript
+{
+public:
+  Subscript(std::initializer_list<std::shared_ptr<Node>> indices) : _indices{indices}
+  {
+    // DO NOTHING
+  }
+
+public:
+  uint32_t rank(void) const { return _indices.size(); }
+
+public:
+  const std::shared_ptr<expr::Node> &at(uint32_t n) const { return _indices.at(n); }
+
+private:
+  std::vector<std::shared_ptr<expr::Node>> _indices;
+};
+
+} // namespace expr
+} // namespace nest
+
+#endif // __NEST_SUBSCRIPT_H__
diff --git a/compiler/nest/core/include/nest/expr/VarNode.h b/compiler/nest/core/include/nest/expr/VarNode.h
new file mode 100644
index 000000000..0767fed41
--- /dev/null
+++ b/compiler/nest/core/include/nest/expr/VarNode.h
@@ -0,0 +1,52 @@
+/*
+ * 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.
+ */
+
+#ifndef __NEXT_EXPR_VAR_NODE_H__
+#define __NEXT_EXPR_VAR_NODE_H__
+
+#include "nest/VarID.h"
+
+#include "nest/expr/Forward.h"
+#include "nest/expr/Visitor.h"
+#include "nest/expr/Node.h"
+
+namespace nest
+{
+namespace expr
+{
+
+class VarNode final : public Node
+{
+public:
+  VarNode(const VarID &id) : _id{id}
+  {
+    // DO NOTHING
+  }
+
+public:
+  const VarNode *asVar(void) const override { return this; }
+
+public:
+  const VarID &id(void) const { return _id; }
+
+private:
+  VarID const _id;
+};
+
+} // namespace expr
+} // namespace nest
+
+#endif // __NEXT_EXPR_VAR_NODE_H__
diff --git a/compiler/nest/core/include/nest/expr/Visitor.h b/compiler/nest/core/include/nest/expr/Visitor.h
new file mode 100644
index 000000000..84f70e9f4
--- /dev/null
+++ b/compiler/nest/core/include/nest/expr/Visitor.h
@@ -0,0 +1,40 @@
+/*
+ * 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.
+ */
+
+#ifndef __NEST_EXPR_VISITOR_H__
+#define __NEST_EXPR_VISITOR_H__
+
+#include "nest/expr/Macro.h"
+#include "nest/expr/Forward.h"
+
+namespace nest
+{
+namespace expr
+{
+
+template <typename T> struct Visitor
+{
+  virtual ~Visitor() = default;
+
+#define EXPR(Tag) virtual T visit(const NEST_EXPR_CLASS_NAME(Tag) *) = 0;
+#include "nest/expr/Node.def"
+#undef EXPR
+};
+
+} // namespace expr
+} // namespace nest
+
+#endif // __NEST_EXPR_VISITOR_H__
diff --git a/compiler/nest/core/include/nest/stmt/Forward.h b/compiler/nest/core/include/nest/stmt/Forward.h
new file mode 100644
index 000000000..349898e42
--- /dev/null
+++ b/compiler/nest/core/include/nest/stmt/Forward.h
@@ -0,0 +1,34 @@
+/*
+ * 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.
+ */
+
+#ifndef __NEST_STMT_FORWARD_H__
+#define __NEST_STMT_FORWARD_H__
+
+#include "nest/stmt/Macro.h"
+
+namespace nest
+{
+namespace stmt
+{
+
+#define STMT(Tag) class NEST_STMT_CLASS_NAME(Tag);
+#include "nest/stmt/Node.def"
+#undef STMT
+
+} // namespace stmt
+} // namespace nest
+
+#endif // __NEST_STMT_FORWARD_H__
diff --git a/compiler/nest/core/include/nest/stmt/Macro.h b/compiler/nest/core/include/nest/stmt/Macro.h
new file mode 100644
index 000000000..f8cd8941e
--- /dev/null
+++ b/compiler/nest/core/include/nest/stmt/Macro.h
@@ -0,0 +1,28 @@
+/*
+ * 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.
+ */
+
+#ifndef __NEST_STMT_MACRO_H__
+#define __NEST_STMT_MACRO_H__
+
+#ifndef NEST_STMT_CLASS_NAME
+#define NEST_STMT_CLASS_NAME(Tag) Tag##Node
+#endif // NEST_STMT_CLASS_NAME
+
+#ifndef NEST_STMT_CAST_METHOD_NAME
+#define NEST_STMT_CAST_METHOD_NAME(Tag) as##Tag
+#endif // STMT_CAST_METHOD_NAME
+
+#endif // __NEST_STMT_MACRO_H__
diff --git a/compiler/nest/core/include/nest/stmt/Node.def b/compiler/nest/core/include/nest/stmt/Node.def
new file mode 100644
index 000000000..dcec9147f
--- /dev/null
+++ b/compiler/nest/core/include/nest/stmt/Node.def
@@ -0,0 +1,6 @@
+#ifndef STMT
+#error STMT is should be defined before including this file
+#endif
+
+// STMT(Tag)
+STMT(Push)
diff --git a/compiler/nest/core/include/nest/stmt/Node.h b/compiler/nest/core/include/nest/stmt/Node.h
new file mode 100644
index 000000000..593eb68a1
--- /dev/null
+++ b/compiler/nest/core/include/nest/stmt/Node.h
@@ -0,0 +1,62 @@
+/*
+ * 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.
+ */
+
+#ifndef __NEST_STMT_NODE_H__
+#define __NEST_STMT_NODE_H__
+
+#include "nest/stmt/Macro.h"
+#include "nest/stmt/Forward.h"
+#include "nest/stmt/Visitor.h"
+
+#include <stdexcept>
+
+namespace nest
+{
+namespace stmt
+{
+
+struct Node
+{
+  virtual ~Node() = default;
+
+#define STMT(Tag)                                                                       \
+  virtual const NEST_STMT_CLASS_NAME(Tag) * NEST_STMT_CAST_METHOD_NAME(Tag)(void) const \
+  {                                                                                     \
+    return nullptr;                                                                     \
+  }
+#include "nest/stmt/Node.def"
+#undef STMT
+
+  template <typename T> T accept(Visitor<T> *v)
+  {
+#define STMT(Tag)                                 \
+  if (auto s = NEST_STMT_CAST_METHOD_NAME(Tag)()) \
+  {                                               \
+    return v->visit(s);                           \
+  }
+#include "nest/stmt/Node.def"
+#undef STMT
+
+    throw std::runtime_error{"unreachable"};
+  }
+
+  template <typename T> T accept(Visitor<T> &v) { return accept(&v); }
+};
+
+} // namespace stmt
+} // namespace nest
+
+#endif // __NEST_STMT_NODE_H__
diff --git a/compiler/nest/core/include/nest/stmt/PushNode.h b/compiler/nest/core/include/nest/stmt/PushNode.h
new file mode 100644
index 000000000..8a6b3cd91
--- /dev/null
+++ b/compiler/nest/core/include/nest/stmt/PushNode.h
@@ -0,0 +1,49 @@
+/*
+ * 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.
+ */
+
+#ifndef __NEST_STMT_PUSH_NODE_H__
+#define __NEST_STMT_PUSH_NODE_H__
+
+#include "nest/stmt/Node.h"
+#include "nest/Expr.h"
+
+namespace nest
+{
+namespace stmt
+{
+
+class PushNode final : public Node
+{
+public:
+  PushNode(const Expr &expr) : _expr{expr}
+  {
+    // DO NOTHING
+  }
+
+public:
+  const PushNode *asPush(void) const override { return this; }
+
+public:
+  const Expr &expr(void) const { return _expr; }
+
+private:
+  Expr const _expr;
+};
+
+} // namespace stmt
+} // namespace nest
+
+#endif // __NEST_STMT_PUSH_NODE_H__
diff --git a/compiler/nest/core/include/nest/stmt/Visitor.h b/compiler/nest/core/include/nest/stmt/Visitor.h
new file mode 100644
index 000000000..459f0c9d6
--- /dev/null
+++ b/compiler/nest/core/include/nest/stmt/Visitor.h
@@ -0,0 +1,40 @@
+/*
+ * 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.
+ */
+
+#ifndef __NEST_STMT_VISITOR_H__
+#define __NEST_STMT_VISITOR_H__
+
+#include "nest/stmt/Macro.h"
+#include "nest/stmt/Forward.h"
+
+namespace nest
+{
+namespace stmt
+{
+
+template <typename T> struct Visitor
+{
+  virtual ~Visitor() = default;
+
+#define STMT(Tag) virtual T visit(const NEST_STMT_CLASS_NAME(Tag) *) = 0;
+#include "nest/stmt/Node.def"
+#undef STMT
+};
+
+} // namespace stmt
+} // namespace nest
+
+#endif // __NEST_STMT_VISITOR_H__
diff --git a/compiler/nest/core/src/Block.test.cpp b/compiler/nest/core/src/Block.test.cpp
new file mode 100644
index 000000000..b40fbeaac
--- /dev/null
+++ b/compiler/nest/core/src/Block.test.cpp
@@ -0,0 +1,41 @@
+/*
+ * 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 "nest/Block.h"
+
+#include <gtest/gtest.h>
+
+namespace
+{
+struct DummyNode final : public nest::stmt::Node
+{
+  // Dummy Node for testing
+};
+}
+
+TEST(BLOCK, use_case_1)
+{
+  nest::Block block;
+
+  ASSERT_EQ(block.size(), 0);
+
+  auto stmt = std::make_shared<DummyNode>();
+
+  block.append(stmt);
+
+  ASSERT_EQ(block.size(), 1);
+  ASSERT_EQ(block.at(0), stmt);
+}
diff --git a/compiler/nest/core/src/Bound.test.cpp b/compiler/nest/core/src/Bound.test.cpp
new file mode 100644
index 000000000..7b2f0b62e
--- /dev/null
+++ b/compiler/nest/core/src/Bound.test.cpp
@@ -0,0 +1,27 @@
+/*
+ * 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 "nest/Bound.h"
+
+#include <gtest/gtest.h>
+
+TEST(BOUND, ctor)
+{
+  const nest::Bound b{-10, 20};
+
+  ASSERT_EQ(b.min(), -10);
+  ASSERT_EQ(b.max(), 20);
+}
diff --git a/compiler/nest/core/src/Closure.cpp b/compiler/nest/core/src/Closure.cpp
new file mode 100644
index 000000000..253a612f8
--- /dev/null
+++ b/compiler/nest/core/src/Closure.cpp
@@ -0,0 +1,24 @@
+/*
+ * 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 "nest/Closure.h"
+
+namespace nest
+{
+
+Closure::operator Expr(void) const { return std::make_shared<expr::DerefNode>(_id, _sub); }
+
+} // namespace nest
diff --git a/compiler/nest/core/src/Closure.test.cpp b/compiler/nest/core/src/Closure.test.cpp
new file mode 100644
index 000000000..1dae849a3
--- /dev/null
+++ b/compiler/nest/core/src/Closure.test.cpp
@@ -0,0 +1,45 @@
+/*
+ * 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 "nest/Closure.h"
+
+#include <gtest/gtest.h>
+
+namespace
+{
+struct DummyNode final : public nest::expr::Node
+{
+};
+}
+
+TEST(Closure, ctor)
+{
+  nest::DomainID dom_id{0};
+  nest::Closure closure{dom_id, std::make_shared<DummyNode>()};
+
+  ASSERT_EQ(closure.id().value(), 0);
+  ASSERT_EQ(closure.sub().rank(), 1);
+}
+
+TEST(Closure, cast)
+{
+  nest::DomainID dom_id{0};
+  nest::Closure closure{dom_id, std::make_shared<DummyNode>()};
+
+  auto check = [](const nest::Expr &e) { ASSERT_NE(e.get(), nullptr); };
+
+  check(closure);
+}
diff --git a/compiler/nest/core/src/Domain.test.cpp b/compiler/nest/core/src/Domain.test.cpp
new file mode 100644
index 000000000..5f973ecf7
--- /dev/null
+++ b/compiler/nest/core/src/Domain.test.cpp
@@ -0,0 +1,41 @@
+/*
+ * 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 "nest/Domain.h"
+
+#include <gtest/gtest.h>
+
+namespace
+{
+namespace expr
+{
+struct DummyNode final : public nest::expr::Node
+{
+};
+} // namespace expr
+} // namespace
+
+// NOTE Build failed when DOMAIN is used instead of _DOMAIN
+TEST(_DOMAIN, base_usecase)
+{
+  nest::DomainID dom_id{0};
+  nest::Domain dom{dom_id};
+
+  nest::Closure clo = dom(std::make_shared<::expr::DummyNode>());
+
+  ASSERT_EQ(clo.id(), dom_id);
+  ASSERT_EQ(clo.sub().rank(), 1);
+}
diff --git a/compiler/nest/core/src/DomainContext.cpp b/compiler/nest/core/src/DomainContext.cpp
new file mode 100644
index 000000000..4a7f223d4
--- /dev/null
+++ b/compiler/nest/core/src/DomainContext.cpp
@@ -0,0 +1,38 @@
+/*
+ * 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 "nest/DomainContext.h"
+
+namespace nest
+{
+
+uint32_t DomainContext::count(void) const { return _info.size(); }
+
+Domain DomainContext::make(std::initializer_list<uint32_t> dims)
+{
+  const DomainID domain_id{count()};
+
+  _info.emplace_back(dims);
+
+  return Domain{domain_id};
+}
+
+const DomainInfo &DomainContext::info(const Domain &dom) const
+{
+  return _info.at(dom.id().value());
+}
+
+} // namespace nest
diff --git a/compiler/nest/core/src/DomainContext.test.cpp b/compiler/nest/core/src/DomainContext.test.cpp
new file mode 100644
index 000000000..10882df70
--- /dev/null
+++ b/compiler/nest/core/src/DomainContext.test.cpp
@@ -0,0 +1,56 @@
+/*
+ * 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 "nest/DomainContext.h"
+
+#include <gtest/gtest.h>
+
+TEST(DOMAIN_CONTEXT, usecase)
+{
+  nest::DomainContext ctx;
+
+  auto dom_0 = ctx.make({1, 3, 4});
+
+  ASSERT_EQ(ctx.count(), 1);
+
+  auto check_dom_0 = [&](void) {
+    ASSERT_EQ(ctx.info(dom_0).rank(), 3);
+    ASSERT_EQ(ctx.info(dom_0).dim(0), 1);
+    ASSERT_EQ(ctx.info(dom_0).dim(1), 3);
+    ASSERT_EQ(ctx.info(dom_0).dim(2), 4);
+  };
+
+  check_dom_0();
+
+  auto dom_1 = ctx.make({7, 6, 2, 1});
+
+  ASSERT_EQ(ctx.count(), 2);
+
+  // Domain ID should be unique for each domain
+  ASSERT_FALSE(dom_0.id() == dom_1.id());
+
+  auto check_dom_1 = [&](void) {
+    ASSERT_EQ(ctx.info(dom_1).rank(), 4);
+    ASSERT_EQ(ctx.info(dom_1).dim(0), 7);
+    ASSERT_EQ(ctx.info(dom_1).dim(1), 6);
+    ASSERT_EQ(ctx.info(dom_1).dim(2), 2);
+    ASSERT_EQ(ctx.info(dom_1).dim(3), 1);
+  };
+
+  // make() SHOULD NOT affect the existing domain information
+  check_dom_0();
+  check_dom_1();
+}
diff --git a/compiler/nest/core/src/DomainID.cpp b/compiler/nest/core/src/DomainID.cpp
new file mode 100644
index 000000000..714f07b67
--- /dev/null
+++ b/compiler/nest/core/src/DomainID.cpp
@@ -0,0 +1,30 @@
+/*
+ * 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 "nest/DomainID.h"
+
+namespace nest
+{
+
+DomainID::DomainID() : _value{0xffffffff}
+{
+  // DO NOTHING
+}
+
+bool operator==(const DomainID &lhs, const DomainID &rhs) { return lhs.value() == rhs.value(); }
+bool operator<(const DomainID &lhs, const DomainID &rhs) { return lhs.value() < rhs.value(); }
+
+} // namespace nest
diff --git a/compiler/nest/core/src/DomainID.test.cpp b/compiler/nest/core/src/DomainID.test.cpp
new file mode 100644
index 000000000..6b1ce8360
--- /dev/null
+++ b/compiler/nest/core/src/DomainID.test.cpp
@@ -0,0 +1,38 @@
+/*
+ * 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 "nest/DomainID.h"
+
+#include <gtest/gtest.h>
+
+TEST(DOMAIN_ID, ctor)
+{
+  nest::DomainID id{0};
+
+  ASSERT_EQ(id.value(), 0);
+}
+
+TEST(DOMAIN_ID, operator_eq)
+{
+  ASSERT_TRUE(nest::DomainID(0) == nest::DomainID(0));
+  ASSERT_FALSE(nest::DomainID(0) == nest::DomainID(1));
+}
+
+TEST(DOMAIN_ID, operator_lt)
+{
+  ASSERT_TRUE(nest::DomainID(0) < nest::DomainID(1));
+  ASSERT_FALSE(nest::DomainID(1) < nest::DomainID(0));
+}
diff --git a/compiler/nest/core/src/DomainInfo.test.cpp b/compiler/nest/core/src/DomainInfo.test.cpp
new file mode 100644
index 000000000..7a5d81144
--- /dev/null
+++ b/compiler/nest/core/src/DomainInfo.test.cpp
@@ -0,0 +1,30 @@
+/*
+ * 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 "nest/DomainInfo.h"
+
+#include <gtest/gtest.h>
+
+TEST(DOMAIN_INFO, ctor)
+{
+  nest::DomainInfo info{1, 2, 3, 4};
+
+  ASSERT_EQ(info.rank(), 4);
+  ASSERT_EQ(info.dim(0), 1);
+  ASSERT_EQ(info.dim(1), 2);
+  ASSERT_EQ(info.dim(2), 3);
+  ASSERT_EQ(info.dim(3), 4);
+}
diff --git a/compiler/nest/core/src/Expr.cpp b/compiler/nest/core/src/Expr.cpp
new file mode 100644
index 000000000..6d35f4c5a
--- /dev/null
+++ b/compiler/nest/core/src/Expr.cpp
@@ -0,0 +1,27 @@
+/*
+ * 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 "nest/Expr.h"
+
+nest::Expr operator+(const nest::Expr &lhs, const nest::Expr &rhs)
+{
+  return std::make_shared<nest::expr::AddNode>(lhs, rhs);
+}
+
+nest::Expr operator*(const nest::Expr &lhs, const nest::Expr &rhs)
+{
+  return std::make_shared<nest::expr::MulNode>(lhs, rhs);
+}
diff --git a/compiler/nest/core/src/Expr.test.cpp b/compiler/nest/core/src/Expr.test.cpp
new file mode 100644
index 000000000..0c96f7714
--- /dev/null
+++ b/compiler/nest/core/src/Expr.test.cpp
@@ -0,0 +1,58 @@
+/*
+ * 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 "nest/Expr.h"
+
+#include <memory>
+
+#include <gtest/gtest.h>
+
+namespace
+{
+struct DummyNode final : public nest::expr::Node
+{
+};
+}
+
+TEST(EXPR, operator_sum)
+{
+  auto left = std::make_shared<DummyNode>();
+  auto right = std::make_shared<DummyNode>();
+
+  auto expr = left + right;
+
+  ASSERT_NE(expr->asAdd(), nullptr);
+
+  auto add = expr->asAdd();
+
+  ASSERT_EQ(add->lhs().get(), left.get());
+  ASSERT_EQ(add->rhs().get(), right.get());
+}
+
+TEST(EXPR, operator_mul)
+{
+  auto left = std::make_shared<DummyNode>();
+  auto right = std::make_shared<DummyNode>();
+
+  auto expr = left * right;
+
+  ASSERT_NE(expr->asMul(), nullptr);
+
+  auto add = expr->asMul();
+
+  ASSERT_EQ(add->lhs().get(), left.get());
+  ASSERT_EQ(add->rhs().get(), right.get());
+}
diff --git a/compiler/nest/core/src/FV.cpp b/compiler/nest/core/src/FV.cpp
new file mode 100644
index 000000000..2b51d178c
--- /dev/null
+++ b/compiler/nest/core/src/FV.cpp
@@ -0,0 +1,75 @@
+/*
+ * 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 "nest/FV.h"
+
+namespace
+{
+
+using namespace nest;
+using namespace nest::expr;
+
+class Collector final : public Visitor<void>
+{
+public:
+  Collector(std::set<VarID> &out) : _out(out)
+  {
+    // DO NOTHING
+  }
+
+public:
+  void visit(const VarNode *e) override { _out.insert(e->id()); }
+
+  void visit(const DerefNode *e) override
+  {
+    for (uint32_t n = 0; n < e->sub().rank(); ++n)
+    {
+      e->sub().at(n)->accept(this);
+    }
+  }
+
+  void visit(const AddNode *e) override
+  {
+    e->lhs()->accept(this);
+    e->rhs()->accept(this);
+  }
+
+  void visit(const MulNode *e) override
+  {
+    e->lhs()->accept(this);
+    e->rhs()->accept(this);
+  }
+
+private:
+  std::set<nest::VarID> &_out;
+};
+
+} // namespace
+
+namespace nest
+{
+
+std::set<VarID> FV::in(const Expr &expr)
+{
+  std::set<VarID> res;
+
+  Collector collector{res};
+  expr->accept(collector);
+
+  return res;
+}
+
+} // namespace nest
diff --git a/compiler/nest/core/src/FV.test.cpp b/compiler/nest/core/src/FV.test.cpp
new file mode 100644
index 000000000..55f5f5877
--- /dev/null
+++ b/compiler/nest/core/src/FV.test.cpp
@@ -0,0 +1,75 @@
+/*
+ * 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 "nest/FV.h"
+#include "nest/Module.h"
+
+#include <gtest/gtest.h>
+
+TEST(FV, var_expr)
+{
+  nest::Module m;
+
+  auto var = m.var().make();
+
+  auto fvs = nest::FV::in(var);
+
+  ASSERT_EQ(fvs.size(), 1);
+  ASSERT_NE(fvs.find(var.id()), fvs.end());
+}
+
+TEST(FV, deref_expr)
+{
+  nest::Module m;
+
+  auto dom = m.domain().make({16});
+  auto var = m.var().make();
+
+  auto fvs = nest::FV::in(dom(var));
+
+  ASSERT_EQ(fvs.size(), 1);
+  ASSERT_NE(fvs.find(var.id()), fvs.end());
+}
+
+TEST(FV, add_expr)
+{
+  nest::Module m;
+
+  auto v_0 = m.var().make();
+  auto v_1 = m.var().make();
+
+  auto fvs = nest::FV::in(v_0 + v_1);
+
+  ASSERT_EQ(fvs.size(), 2);
+  ASSERT_NE(fvs.find(v_0.id()), fvs.end());
+  ASSERT_NE(fvs.find(v_1.id()), fvs.end());
+}
+
+TEST(FV, mul_expr)
+{
+  nest::Module m;
+
+  auto v_0 = m.var().make();
+  auto v_1 = m.var().make();
+
+  nest::FV fv;
+
+  auto fvs = nest::FV::in(v_0 * v_1);
+
+  ASSERT_EQ(fvs.size(), 2);
+  ASSERT_NE(fvs.find(v_0.id()), fvs.end());
+  ASSERT_NE(fvs.find(v_1.id()), fvs.end());
+}
diff --git a/compiler/nest/core/src/Level.cpp b/compiler/nest/core/src/Level.cpp
new file mode 100644
index 000000000..1adf4351d
--- /dev/null
+++ b/compiler/nest/core/src/Level.cpp
@@ -0,0 +1,48 @@
+/*
+ * 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 "nest/Level.h"
+
+#include <cassert>
+
+namespace
+{
+const uint32_t invalid_tag = 0xffffffff;
+} // namespace
+
+namespace nest
+{
+Level::Level() : _value{invalid_tag}
+{
+  // DO NOTHING
+}
+
+Level::Level(uint32_t value) : _value{value} { assert(value != invalid_tag); }
+
+bool Level::valid(void) const { return _value != invalid_tag; }
+
+bool operator==(const Level &lhs, const Level &rhs)
+{
+  assert(lhs.valid() && rhs.valid());
+  return lhs.value() == rhs.value();
+}
+
+bool operator<(const Level &lhs, const Level &rhs)
+{
+  assert(lhs.valid() && rhs.valid());
+  return lhs.value() < rhs.value();
+}
+} // namespace nest
diff --git a/compiler/nest/core/src/Level.test.cpp b/compiler/nest/core/src/Level.test.cpp
new file mode 100644
index 000000000..b9e203d9d
--- /dev/null
+++ b/compiler/nest/core/src/Level.test.cpp
@@ -0,0 +1,39 @@
+/*
+ * 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 "nest/Level.h"
+
+#include <gtest/gtest.h>
+
+TEST(LEVEL, constructor)
+{
+  nest::Level lv{3};
+
+  ASSERT_EQ(lv.value(), 3);
+}
+
+TEST(LEVEL, operator_eq)
+{
+  ASSERT_TRUE(nest::Level(3) == nest::Level(3));
+  ASSERT_FALSE(nest::Level(3) == nest::Level(4));
+}
+
+TEST(LEVEL, operator_lt)
+{
+  ASSERT_FALSE(nest::Level(3) < nest::Level(3));
+  ASSERT_TRUE(nest::Level(3) < nest::Level(4));
+  ASSERT_FALSE(nest::Level(4) < nest::Level(3));
+}
diff --git a/compiler/nest/core/src/Module.cpp b/compiler/nest/core/src/Module.cpp
new file mode 100644
index 000000000..060f94e3e
--- /dev/null
+++ b/compiler/nest/core/src/Module.cpp
@@ -0,0 +1,44 @@
+/*
+ * 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 "nest/Module.h"
+
+#include <cassert>
+
+namespace nest
+{
+
+void Module::push(const Expr &expr)
+{
+  auto stmt = std::make_shared<stmt::PushNode>(expr);
+  _block.append(stmt);
+}
+
+void Module::ret(const Closure &clo)
+{
+  // Only one RET is allowed for each module
+  assert(_ret == nullptr);
+  _ret = std::make_shared<Ret>(clo.id(), clo.sub());
+}
+
+const Ret &Module::ret(void) const
+{
+  // Caller should NOT invoke this method before setting ret
+  assert(_ret != nullptr);
+  return *_ret;
+}
+
+} // namespace nest
diff --git a/compiler/nest/core/src/Module.test.cpp b/compiler/nest/core/src/Module.test.cpp
new file mode 100644
index 000000000..01e414d25
--- /dev/null
+++ b/compiler/nest/core/src/Module.test.cpp
@@ -0,0 +1,99 @@
+/*
+ * 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 "nest/Module.h"
+
+#include <gtest/gtest.h>
+
+TEST(MODULE, create_var)
+{
+  nest::Module m;
+
+  auto create = [](nest::Module &m) {
+    // This code will invoke 'VarContext &var(void)' method
+    return m.var().make();
+  };
+
+  auto check = [](const nest::Module &m) {
+    // This code will invoke 'const VarContext &var(void) const' method
+    ASSERT_EQ(m.var().count(), 1);
+  };
+
+  create(m);
+  check(m);
+}
+
+TEST(MODULE, create_domain)
+{
+  nest::Module m;
+
+  auto create = [](nest::Module &m, std::initializer_list<uint32_t> dims) {
+    // This code will invoke 'DomainContext &domain(void)' method
+    return m.domain().make(dims);
+  };
+
+  auto check = [](const nest::Module &m) {
+    // This code will invoke 'const DomainContext &domain(void) const' method
+    ASSERT_EQ(m.domain().count(), 1);
+  };
+
+  create(m, {1, 3, 3});
+  check(m);
+}
+
+TEST(MODULE, push)
+{
+  nest::Module m;
+
+  auto ifm = m.domain().make({1, 3, 3});
+
+  auto var_ch = m.var().make();
+  auto var_row = m.var().make();
+  auto var_col = m.var().make();
+
+  m.push(ifm(var_ch, var_row, var_col));
+
+  ASSERT_EQ(m.block().size(), 1);
+  ASSERT_NE(m.block().at(0)->asPush(), nullptr);
+}
+
+TEST(MODULE, ret)
+{
+  nest::Module m;
+
+  auto ifm = m.domain().make({1});
+  auto ofm = m.domain().make({1});
+
+  auto ind = m.var().make();
+
+  m.push(ifm(ind));
+  m.ret(ofm(ind));
+
+  ASSERT_EQ(m.ret().id(), ofm.id());
+  ASSERT_EQ(m.ret().sub().rank(), 1);
+}
+
+TEST(MODULE, copy)
+{
+  nest::Module orig;
+  nest::Module copy;
+
+  orig = copy;
+
+  orig.var().make();
+
+  ASSERT_EQ(copy.var().count(), 0);
+}
diff --git a/compiler/nest/core/src/Ret.test.cpp b/compiler/nest/core/src/Ret.test.cpp
new file mode 100644
index 000000000..703f04901
--- /dev/null
+++ b/compiler/nest/core/src/Ret.test.cpp
@@ -0,0 +1,58 @@
+/*
+ * 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 "nest/Ret.h"
+
+#include <gtest/gtest.h>
+
+namespace
+{
+struct DummyNode final : public nest::expr::Node
+{
+};
+}
+
+TEST(RET, ctor)
+{
+  nest::DomainID dom_id{0};
+  nest::expr::Subscript sub{std::make_shared<DummyNode>()};
+
+  nest::Ret ret{dom_id, sub};
+
+  ASSERT_EQ(ret.id().value(), 0);
+  ASSERT_EQ(ret.sub().rank(), 1);
+}
+
+TEST(RET, copy)
+{
+  nest::DomainID src_id{0};
+  nest::expr::Subscript src_sub{std::make_shared<DummyNode>()};
+
+  const nest::Ret src{src_id, src_sub};
+
+  nest::DomainID dst_id{1};
+  nest::expr::Subscript dst_sub{std::make_shared<DummyNode>(), std::make_shared<DummyNode>()};
+
+  nest::Ret dst{dst_id, dst_sub};
+
+  ASSERT_EQ(dst.id().value(), 1);
+  ASSERT_EQ(dst.sub().rank(), 2);
+
+  dst = src;
+
+  ASSERT_EQ(dst.id().value(), 0);
+  ASSERT_EQ(dst.sub().rank(), 1);
+}
diff --git a/compiler/nest/core/src/Schedule.cpp b/compiler/nest/core/src/Schedule.cpp
new file mode 100644
index 000000000..81f9cd26a
--- /dev/null
+++ b/compiler/nest/core/src/Schedule.cpp
@@ -0,0 +1,51 @@
+/*
+ * 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 "nest/Schedule.h"
+
+#include <cassert>
+#include <stdexcept>
+
+namespace nest
+{
+
+Schedule::Schedule(const Module &module) : _module{module}
+{
+  // NOTE This implementation assumes that VarContext sequentially assigns VarID
+  for (uint32_t n = 0; n < _module.var().count(); ++n)
+  {
+    _level.emplace_back(VarID{n});
+  }
+
+  assert(_level.size() == _module.var().count());
+}
+
+Var Schedule::at(const Level &lv) const { return Var{_level.at(lv.value())}; }
+
+Level Schedule::level(const Var &var) const
+{
+  for (uint32_t lv = 0; lv < _level.size(); ++lv)
+  {
+    if (_level.at(lv) == var.id())
+    {
+      return Level{lv};
+    }
+  }
+
+  throw std::invalid_argument{"var"};
+}
+
+} // namespace nest
diff --git a/compiler/nest/core/src/Schedule.test.cpp b/compiler/nest/core/src/Schedule.test.cpp
new file mode 100644
index 000000000..8f0ddb23c
--- /dev/null
+++ b/compiler/nest/core/src/Schedule.test.cpp
@@ -0,0 +1,44 @@
+/*
+ * 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 "nest/Schedule.h"
+
+#include <gtest/gtest.h>
+
+TEST(SCHEDULE, module)
+{
+  nest::Module m;
+
+  auto var_1 = m.var().make();
+
+  nest::Schedule sch{m};
+
+  ASSERT_EQ(sch.level(var_1).value(), 0);
+}
+
+TEST(SCHEDULE, module_copy)
+{
+  nest::Module m;
+
+  m.var().make();
+
+  nest::Schedule sch{m};
+
+  // Update on 'm' does not affect the schedule
+  m.var().make();
+
+  ASSERT_EQ(sch.var().count(), 1);
+}
diff --git a/compiler/nest/core/src/Var.cpp b/compiler/nest/core/src/Var.cpp
new file mode 100644
index 000000000..93ce6e43b
--- /dev/null
+++ b/compiler/nest/core/src/Var.cpp
@@ -0,0 +1,24 @@
+/*
+ * 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 "nest/Var.h"
+
+namespace nest
+{
+
+Var::operator Expr(void) const { return std::make_shared<expr::VarNode>(_id); }
+
+} // namespace nest
diff --git a/compiler/nest/core/src/Var.test.cpp b/compiler/nest/core/src/Var.test.cpp
new file mode 100644
index 000000000..29f879558
--- /dev/null
+++ b/compiler/nest/core/src/Var.test.cpp
@@ -0,0 +1,38 @@
+/*
+ * 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 "nest/Var.h"
+
+#include <gtest/gtest.h>
+
+TEST(VAR, ctor)
+{
+  nest::VarID id{0};
+  nest::Var var{id};
+
+  ASSERT_EQ(var.id(), id);
+}
+
+TEST(VAR, cast)
+{
+  nest::VarID id{0};
+  nest::Var var{id};
+
+  nest::Expr expr = var;
+
+  ASSERT_NE(expr->asVar(), nullptr);
+  ASSERT_EQ(expr->asVar()->id(), id);
+}
diff --git a/compiler/nest/core/src/VarContext.cpp b/compiler/nest/core/src/VarContext.cpp
new file mode 100644
index 000000000..24b1336a7
--- /dev/null
+++ b/compiler/nest/core/src/VarContext.cpp
@@ -0,0 +1,36 @@
+/*
+ * 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 "nest/VarContext.h"
+
+namespace nest
+{
+
+uint32_t VarContext::count(void) const { return _bound.size(); }
+
+Var VarContext::make(void)
+{
+  const VarID vid{count()};
+
+  _bound.emplace_back(0, 0);
+
+  return Var{vid};
+}
+
+Bound &VarContext::bound(const Var &var) { return _bound.at(var.id().value()); }
+const Bound &VarContext::bound(const Var &var) const { return _bound.at(var.id().value()); }
+
+} // namespace nest
diff --git a/compiler/nest/core/src/VarContext.test.cpp b/compiler/nest/core/src/VarContext.test.cpp
new file mode 100644
index 000000000..169bd6126
--- /dev/null
+++ b/compiler/nest/core/src/VarContext.test.cpp
@@ -0,0 +1,82 @@
+/*
+ * 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 "nest/VarContext.h"
+
+#include <gtest/gtest.h>
+
+TEST(VAR_CONTEXT, make)
+{
+  nest::VarContext ctx;
+
+  auto var_0 = ctx.make();
+  auto var_1 = ctx.make();
+
+  ASSERT_FALSE(var_0.id() == var_1.id());
+}
+
+TEST(VAR_CONTEXT, count)
+{
+  nest::VarContext ctx;
+
+  ASSERT_EQ(ctx.count(), 0);
+
+  auto var_0 = ctx.make();
+
+  ASSERT_EQ(ctx.count(), 1);
+
+  auto var_1 = ctx.make();
+
+  ASSERT_EQ(ctx.count(), 2);
+}
+
+TEST(VAR_CONTEXT, bound_one)
+{
+  nest::VarContext ctx;
+
+  auto var_0 = ctx.make();
+
+  ASSERT_EQ(ctx.bound(var_0).min(), 0);
+  ASSERT_EQ(ctx.bound(var_0).max(), 0);
+
+  ctx.bound(var_0) = nest::Bound{-3, 5};
+
+  ASSERT_EQ(ctx.bound(var_0).min(), -3);
+  ASSERT_EQ(ctx.bound(var_0).max(), 5);
+}
+
+TEST(VAR_CONTEXT, bound_independent)
+{
+  nest::VarContext ctx;
+
+  auto var_0 = ctx.make();
+
+  ASSERT_EQ(ctx.bound(var_0).min(), 0);
+  ASSERT_EQ(ctx.bound(var_0).max(), 0);
+
+  auto var_1 = ctx.make();
+
+  ASSERT_EQ(ctx.bound(var_1).min(), 0);
+  ASSERT_EQ(ctx.bound(var_1).max(), 0);
+
+  ctx.bound(var_0) = nest::Bound{-3, 5};
+
+  ASSERT_EQ(ctx.bound(var_0).min(), -3);
+  ASSERT_EQ(ctx.bound(var_0).max(), 5);
+
+  ASSERT_EQ(ctx.bound(var_1).min(), 0);
+  ASSERT_EQ(ctx.bound(var_1).max(), 0);
+}
diff --git a/compiler/nest/core/src/VarID.cpp b/compiler/nest/core/src/VarID.cpp
new file mode 100644
index 000000000..23906764d
--- /dev/null
+++ b/compiler/nest/core/src/VarID.cpp
@@ -0,0 +1,30 @@
+/*
+ * 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 "nest/VarID.h"
+
+namespace nest
+{
+
+VarID::VarID() : _value{0xffffffff}
+{
+  // DO NOTHING
+}
+
+bool operator==(const VarID &lhs, const VarID &rhs) { return lhs.value() == rhs.value(); }
+bool operator<(const VarID &lhs, const VarID &rhs) { return lhs.value() < rhs.value(); }
+
+} // namespace nest
diff --git a/compiler/nest/core/src/VarID.test.cpp b/compiler/nest/core/src/VarID.test.cpp
new file mode 100644
index 000000000..e4a17a5c1
--- /dev/null
+++ b/compiler/nest/core/src/VarID.test.cpp
@@ -0,0 +1,38 @@
+/*
+ * 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 "nest/VarID.h"
+
+#include <gtest/gtest.h>
+
+TEST(VAR_ID, ctor)
+{
+  nest::VarID id{0};
+
+  ASSERT_EQ(id.value(), 0);
+}
+
+TEST(VAR_ID, operator_eq)
+{
+  ASSERT_TRUE(nest::VarID(0) == nest::VarID(0));
+  ASSERT_FALSE(nest::VarID(0) == nest::VarID(1));
+}
+
+TEST(VAR_ID, operator_lt)
+{
+  ASSERT_TRUE(nest::VarID(0) < nest::VarID(1));
+  ASSERT_FALSE(nest::VarID(1) < nest::VarID(0));
+}
diff --git a/compiler/nest/core/src/expr/AddNode.test.cpp b/compiler/nest/core/src/expr/AddNode.test.cpp
new file mode 100644
index 000000000..5c44c4743
--- /dev/null
+++ b/compiler/nest/core/src/expr/AddNode.test.cpp
@@ -0,0 +1,43 @@
+/*
+ * 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 "nest/expr/AddNode.h"
+
+#include <memory>
+
+#include <gtest/gtest.h>
+
+namespace
+{
+struct DummyNode final : public nest::expr::Node
+{
+};
+}
+
+TEST(ADD_NODE, cast)
+{
+  auto left = std::make_shared<DummyNode>();
+  auto right = std::make_shared<DummyNode>();
+
+  auto derived = std::make_shared<nest::expr::AddNode>(left, right);
+  std::shared_ptr<nest::expr::Node> base = derived;
+
+  ASSERT_NE(derived.get(), nullptr);
+  ASSERT_EQ(base->asAdd(), derived.get());
+
+  ASSERT_EQ(derived->lhs().get(), left.get());
+  ASSERT_EQ(derived->rhs().get(), right.get());
+}
diff --git a/compiler/nest/core/src/expr/DerefNode.test.cpp b/compiler/nest/core/src/expr/DerefNode.test.cpp
new file mode 100644
index 000000000..e02a7de0b
--- /dev/null
+++ b/compiler/nest/core/src/expr/DerefNode.test.cpp
@@ -0,0 +1,39 @@
+/*
+ * 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 "nest/expr/DerefNode.h"
+
+#include <memory>
+
+#include <gtest/gtest.h>
+
+namespace
+{
+struct DummyNode final : public nest::expr::Node
+{
+};
+}
+
+TEST(DEREF_NODE, cast)
+{
+  const nest::DomainID dom_id{0};
+
+  auto derived = std::make_shared<nest::expr::DerefNode>(dom_id, std::make_shared<DummyNode>());
+  std::shared_ptr<nest::expr::Node> base = derived;
+
+  ASSERT_NE(derived.get(), nullptr);
+  ASSERT_EQ(base->asDeref(), derived.get());
+}
diff --git a/compiler/nest/core/src/expr/Macro.cpp b/compiler/nest/core/src/expr/Macro.cpp
new file mode 100644
index 000000000..4e7a13e08
--- /dev/null
+++ b/compiler/nest/core/src/expr/Macro.cpp
@@ -0,0 +1,21 @@
+/*
+ * 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 "nest/expr/Macro.h"
+
+// This file checkes the self-completeness of 'nest/expr/Macro.h'.
+//
+// NOTE Please do NOT remove this file.
diff --git a/compiler/nest/core/src/expr/MulNode.test.cpp b/compiler/nest/core/src/expr/MulNode.test.cpp
new file mode 100644
index 000000000..b2d29471c
--- /dev/null
+++ b/compiler/nest/core/src/expr/MulNode.test.cpp
@@ -0,0 +1,43 @@
+/*
+ * 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 "nest/expr/MulNode.h"
+
+#include <memory>
+
+#include <gtest/gtest.h>
+
+namespace
+{
+struct DummyNode final : public nest::expr::Node
+{
+};
+}
+
+TEST(MUL_NODE, cast)
+{
+  auto left = std::make_shared<DummyNode>();
+  auto right = std::make_shared<DummyNode>();
+
+  auto derived = std::make_shared<nest::expr::MulNode>(left, right);
+  std::shared_ptr<nest::expr::Node> base = derived;
+
+  ASSERT_NE(derived.get(), nullptr);
+  ASSERT_EQ(base->asMul(), derived.get());
+
+  ASSERT_EQ(derived->lhs().get(), left.get());
+  ASSERT_EQ(derived->rhs().get(), right.get());
+}
diff --git a/compiler/nest/core/src/expr/Node.cpp b/compiler/nest/core/src/expr/Node.cpp
new file mode 100644
index 000000000..0c162428c
--- /dev/null
+++ b/compiler/nest/core/src/expr/Node.cpp
@@ -0,0 +1,21 @@
+/*
+ * 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 "nest/expr/Node.h"
+
+// This file checkes the self-completeness of 'nest/expr/Node.h'.
+//
+// NOTE Please do NOT remove this file.
diff --git a/compiler/nest/core/src/expr/Subscript.test.cpp b/compiler/nest/core/src/expr/Subscript.test.cpp
new file mode 100644
index 000000000..2f187b86c
--- /dev/null
+++ b/compiler/nest/core/src/expr/Subscript.test.cpp
@@ -0,0 +1,37 @@
+/*
+ * 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 "nest/expr/Subscript.h"
+#include "nest/expr/VarNode.h"
+
+#include <memory>
+
+#include <gtest/gtest.h>
+
+TEST(SUBSCRIPT, ctor)
+{
+  nest::VarID id_0{0};
+  nest::VarID id_1{1};
+
+  auto expr_0 = std::make_shared<nest::expr::VarNode>(id_0);
+  auto expr_1 = std::make_shared<nest::expr::VarNode>(id_1);
+
+  nest::expr::Subscript sub{expr_0, expr_1};
+
+  ASSERT_EQ(sub.rank(), 2);
+  ASSERT_EQ(sub.at(0), expr_0);
+  ASSERT_EQ(sub.at(1), expr_1);
+}
diff --git a/compiler/nest/core/src/expr/VarNode.test.cpp b/compiler/nest/core/src/expr/VarNode.test.cpp
new file mode 100644
index 000000000..e8b2764e4
--- /dev/null
+++ b/compiler/nest/core/src/expr/VarNode.test.cpp
@@ -0,0 +1,47 @@
+/*
+ * 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 "nest/expr/VarNode.h"
+
+#include <memory>
+
+#include <gtest/gtest.h>
+
+TEST(VAR_NODE, ctor)
+{
+  auto make = [](uint32_t n) {
+    const nest::VarID id{n};
+
+    return std::make_shared<nest::expr::VarNode>(id);
+  };
+
+  auto node = make(4);
+
+  // NOTE 'id' should be copied
+  ASSERT_EQ(node->id().value(), 4);
+}
+
+TEST(VAR_NODE, cast)
+{
+  const nest::VarID id{0};
+
+  auto derived = std::make_shared<nest::expr::VarNode>(id);
+  std::shared_ptr<nest::expr::Node> base = derived;
+
+  // NOTE Cast method should be overrided
+  ASSERT_NE(derived.get(), nullptr);
+  ASSERT_EQ(base->asVar(), derived.get());
+}
diff --git a/compiler/nest/core/src/expr/Visitor.cpp b/compiler/nest/core/src/expr/Visitor.cpp
new file mode 100644
index 000000000..531e68951
--- /dev/null
+++ b/compiler/nest/core/src/expr/Visitor.cpp
@@ -0,0 +1,21 @@
+/*
+ * 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 "nest/expr/Visitor.h"
+
+// This file checkes the self-completeness of 'nest/expr/Visitor.h'.
+//
+// NOTE Please do NOT remove this file.
diff --git a/compiler/nest/core/src/stmt/Macro.cpp b/compiler/nest/core/src/stmt/Macro.cpp
new file mode 100644
index 000000000..99adb436c
--- /dev/null
+++ b/compiler/nest/core/src/stmt/Macro.cpp
@@ -0,0 +1,21 @@
+/*
+ * 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 "nest/stmt/Macro.h"
+
+// This file checkes the self-completeness of 'nest/stmt/Macro.h'.
+//
+// NOTE Please do NOT remove this file.
diff --git a/compiler/nest/core/src/stmt/Node.cpp b/compiler/nest/core/src/stmt/Node.cpp
new file mode 100644
index 000000000..6265778d9
--- /dev/null
+++ b/compiler/nest/core/src/stmt/Node.cpp
@@ -0,0 +1,21 @@
+/*
+ * 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 "nest/stmt/Node.h"
+
+// This file checkes the self-completeness of 'nest/stmt/Node.h'.
+//
+// NOTE Please do NOT remove this file.
diff --git a/compiler/nest/core/src/stmt/PushNode.test.cpp b/compiler/nest/core/src/stmt/PushNode.test.cpp
new file mode 100644
index 000000000..a54efbb54
--- /dev/null
+++ b/compiler/nest/core/src/stmt/PushNode.test.cpp
@@ -0,0 +1,37 @@
+/*
+ * 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 "nest/stmt/PushNode.h"
+
+#include <memory>
+
+#include <gtest/gtest.h>
+
+namespace
+{
+struct DummyExprNode final : public nest::expr::Node
+{
+};
+}
+
+TEST(STMT_PUSH_NODE, cast)
+{
+  auto derived = std::make_shared<nest::stmt::PushNode>(std::make_shared<DummyExprNode>());
+  std::shared_ptr<nest::stmt::Node> base = derived;
+
+  ASSERT_NE(derived.get(), nullptr);
+  ASSERT_EQ(base->asPush(), derived.get());
+}
diff --git a/compiler/nest/core/src/stmt/Visitor.cpp b/compiler/nest/core/src/stmt/Visitor.cpp
new file mode 100644
index 000000000..621379bca
--- /dev/null
+++ b/compiler/nest/core/src/stmt/Visitor.cpp
@@ -0,0 +1,21 @@
+/*
+ * 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 "nest/stmt/Visitor.h"
+
+// This file checkes the self-completeness of 'nest/stmt/Visitor.h'.
+//
+// NOTE Please do NOT remove this file.