Basic layouts, tuples (#148)

* Basic layouts, tuples

* Review comments.

* Add incude for size_t.

* Bop use-after-free in GetTupleElement

* Inline call to get_element_types()

src/ngraph/CMakeLists.txt

@@ -13,9 +13,11 @@
 
 set (SRC
     descriptor/input.cpp
+    descriptor/layout/dense_tensor_view_layout.cpp
     descriptor/output.cpp
-    descriptor/tensor_view.cpp
+    descriptor/primary_tensor_view.cpp
     descriptor/tensor.cpp
+    descriptor/tuple.cpp
     function.cpp
     log.cpp
     node.cpp
@@ -27,6 +29,7 @@ set (SRC
     ops/constant.cpp
     ops/convert.cpp
     ops/dot.cpp
+    ops/get_tuple_element.cpp
     ops/op.cpp
     ops/parameter.cpp
     ops/select.cpp
@@ -47,6 +50,8 @@ set (SRC
     pass/visualize_tree.cpp
     runtime/call_frame.cpp
     runtime/external_function.cpp
+    runtime/tuple.cpp
+    runtime/utils.cpp
     shape.cpp
     types/element_type.cpp
     types/type.cpp

src/ngraph/common.hpp

@@ -31,21 +31,21 @@ namespace ngraph
     }
     class ValueType;
 
-    /// Zero or more value types
-    using ValueTypes = std::vector<std::shared_ptr<ValueType>>;
+    /// @brief Zero or more value types
+    using ValueTypes = std::vector<std::shared_ptr<const ValueType>>;
 
-    /// Zero or more nodes
+    /// @brief Zero or more nodes
     using Nodes = std::vector<std::shared_ptr<Node>>;
 
-    /// A sequence of axes
+    /// @brief A sequence of axes
     using AxisVector = std::vector<size_t>;
 
-    /// A set of axes, for example, reduction axes
+    /// @brief A set of axes, for example, reduction axes
     using AxisSet = std::set<size_t>;
 
-    /// Shape for a tensor
+    /// @brief Shape for a tensor
     using Shape = std::vector<size_t>;
 
-    /// Strides of a tensor
+    /// @brief Strides of a tensor
     using Strides = std::vector<size_t>;
 }

src/ngraph/descriptor/buffer.hpp

@@ -14,6 +14,8 @@
 
 #pragma once
 
+#include <memory>
+
 namespace ngraph
 {
     namespace descriptor
@@ -23,8 +25,11 @@ namespace ngraph
         // during execution.
         class Buffer
         {
+        public:
+            size_t size() const { return m_size; }
+
         protected:
-            size_t size;
+            size_t m_size;
         };
     }
 }

src/ngraph/descriptor/buffer_pos.hpp

+// ----------------------------------------------------------------------------
+// Copyright 2017 Nervana Systems Inc.
+// 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
+// ----------------------------------------------------------------------------
+
+#pragma once
+
+#include <cassert>
+
+#include "ngraph/descriptor/buffer.hpp"
+
+namespace ngraph
+{
+    namespace descriptor
+    {
+        /// @brief Specifies a contiguous portion of a buffer.
+        ///
+        /// Currently only implemented for linear buffers.
+        class BufferPos
+        {
+        public:
+            BufferPos() {}
+
+            BufferPos(std::shared_ptr<Buffer> buffer, size_t offset, size_t size)
+                : m_buffer(buffer)
+                , m_offset(offset)
+                , m_size(size)
+            {
+                assert(buffer->size() >= offset + size);
+            }
+
+            BufferPos(const BufferPos& buffer_pos) = default;
+            BufferPos& operator=(const BufferPos& buffer_pos) = default;
+
+        protected:
+            std::shared_ptr<Buffer> m_buffer;
+            size_t                  m_offset;
+            size_t                  m_size;
+        };
+    }
+}

src/ngraph/descriptor/layout/dense_tensor_view_layout.cpp

+// ----------------------------------------------------------------------------
+// Copyright 2017 Nervana Systems Inc.
+// 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
+// ----------------------------------------------------------------------------
+
+#include "ngraph/descriptor/layout/dense_tensor_view_layout.hpp"
+#include "ngraph/except.hpp"
+#include "ngraph/shape.hpp"
+
+using namespace ngraph::descriptor::layout;
+using ngraph::Shape;
+using ngraph::descriptor::TensorView;
+using ngraph::TensorViewType;
+
+DenseTensorViewLayout::DenseTensorViewLayout(const TensorView& tensor_view)
+    : TensorViewLayout(tensor_view)
+{
+    auto  tensor_view_type = tensor_view.get_tensor_view_type();
+    Shape shape            = tensor_view_type->get_shape();
+    m_size                 = ngraph::shape_size(shape);
+    m_strides              = ngraph::row_major_strides(shape);
+}
+
+size_t DenseTensorViewLayout::get_index_offset(const std::vector<size_t>& indices)
+{
+    if (indices.size() != m_strides.size())
+    {
+        throw ngraph_error("Indices have the incorrect rank.");
+    }
+    size_t result = 0;
+    for (int i = 0; i < indices.size(); i++)
+    {
+        result += m_strides[i] + indices[i];
+    }
+    return result;
+}

src/ngraph/descriptor/layout/dense_tensor_view_layout.hpp

+// ----------------------------------------------------------------------------
+// Copyright 2017 Nervana Systems Inc.
+// 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
+// ----------------------------------------------------------------------------
+
+#pragma once
+
+#include <vector>
+
+#include "ngraph/descriptor/buffer.hpp"
+#include "ngraph/descriptor/layout/tensor_view_layout.hpp"
+#include "ngraph/descriptor/tensor_view.hpp"
+
+namespace ngraph
+{
+    namespace descriptor
+    {
+        namespace layout
+        {
+            /// @brief The standard strided layout, used for row-major and column-major, their permutations and slices.
+            ///
+            /// The linearized offset of an index I is dot(I, strides) + offset.
+            class DenseTensorViewLayout : public TensorViewLayout
+            {
+            public:
+                ~DenseTensorViewLayout() {}
+                DenseTensorViewLayout(const TensorView& tensor_view);
+
+                virtual size_t get_size() override { return m_size; }
+                size_t get_offset() const { return m_offset; }
+                virtual size_t get_index_offset(const std::vector<size_t>& indices) override;
+
+            protected:
+                Strides m_strides;
+                size_t  m_offset;
+                size_t  m_size;
+            };
+        }
+    }
+}

src/ngraph/descriptor/layout/tensor_view_layout.hpp

+// ----------------------------------------------------------------------------
+// Copyright 2017 Nervana Systems Inc.
+// 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
+// ----------------------------------------------------------------------------
+
+#pragma once
+
+#include <tuple>
+#include <vector>
+
+#include "ngraph/descriptor/buffer_pos.hpp"
+
+namespace ngraph
+{
+    namespace descriptor
+    {
+        class TensorView;
+
+        namespace layout
+        {
+            /// @brief Interface for describing implementations of tensor views.
+            ///
+            /// Kernel selection will need to pay attention to the layout.
+            class TensorViewLayout
+            {
+            protected:
+                TensorViewLayout(const ngraph::descriptor::TensorView& tensor_view)
+                    : m_tensor_view(tensor_view)
+                {
+                }
+
+            public:
+                virtual ~TensorViewLayout() {}
+
+                /// Extent of this view in buffer.
+                ///
+                /// When we support non-linear buffers, this will need to be something other than size_t.
+                virtual size_t get_size() = 0;
+
+                /// Offset of an index; useful for slice implementation.
+                ///
+                /// With non-linear buffers, this will need to be something other than size_t.
+                virtual size_t get_index_offset(const std::vector<size_t>& indices) = 0;
+
+                /// Where this view is located in the buffer.
+                const BufferPos& get_buffer_pos() const { return m_buffer_pos; }
+                BufferPos&       get_buffer_pos() { return m_buffer_pos; }
+
+            protected:
+                const ngraph::descriptor::TensorView& m_tensor_view;
+                BufferPos                             m_buffer_pos;
+            };
+        }
+    }
+}

src/ngraph/descriptor/tensor_view.cpp → src/ngraph/descriptor/primary_tensor_view.cpp

@@ -12,15 +12,17 @@
 // See the License for the specific language governing permissions and
 // ----------------------------------------------------------------------------
 
-#include "ngraph/descriptor/tensor_view.hpp"
+#include "ngraph/descriptor/primary_tensor_view.hpp"
 
 using namespace ngraph;
 using namespace descriptor;
 
 PrimaryTensorView::PrimaryTensorView(const std::shared_ptr<const TensorViewType>& tensor_view_type,
-    const Node* parent, size_t value_index)
+                                     const std::string&                           name,
+                                     bool                                         is_output,
+                                     bool                                         is_input)
     : TensorView(tensor_view_type)
-    , m_tensor(tensor_view_type->get_element_type(), this, parent, value_index)
+    , m_tensor(tensor_view_type->get_element_type(), this, name, is_output, is_input)
 {
     // Set the name in the parent TensorView.
     // This can't be done until after the m_tensor is constructed.

src/ngraph/descriptor/primary_tensor_view.hpp

+// ----------------------------------------------------------------------------
+// Copyright 2017 Nervana Systems Inc.
+// 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
+// ----------------------------------------------------------------------------
+
+#pragma once
+
+#include <string>
+
+#include "ngraph/descriptor/tensor.hpp"
+#include "ngraph/descriptor/tensor_view.hpp"
+#include "ngraph/log.hpp"
+#include "ngraph/shape.hpp"
+#include "ngraph/types/type.hpp"
+
+namespace ngraph
+{
+    class Node;
+
+    namespace descriptor
+    {
+        class Tensor;
+        class TensorViewLayout;
+
+        /// @brief A PrimaryTensorView owns the tensor. All other views are the result
+        /// of some index operation on the primary view.
+        class PrimaryTensorView : public TensorView
+        {
+        public:
+            /// @param tensor_view_type The type for this view.
+            /// @param name Description of the tensor, for debugging.
+            /// @param is_output The view can be read from the host at the end of a computation.
+            /// @param is_input The view can be written from the host at the beginning of a computation.
+            PrimaryTensorView(const std::shared_ptr<const TensorViewType>& tensor_view_type,
+                              const std::string&                           name,
+                              bool                                         is_output,
+                              bool                                         is_input);
+
+            virtual const Tensor& get_tensor() const override;
+            virtual Tensor&       get_tensor() override;
+
+        protected:
+            Tensor m_tensor;
+        };
+    }
+}

src/ngraph/descriptor/tensor.cpp

@@ -13,7 +13,7 @@
 // ----------------------------------------------------------------------------
 
 #include "ngraph/descriptor/tensor.hpp"
-#include "ngraph/descriptor/tensor_view.hpp"
+#include "ngraph/descriptor/primary_tensor_view.hpp"
 #include "ngraph/node.hpp"
 
 using namespace ngraph;
@@ -21,14 +21,15 @@ using namespace ngraph::descriptor;
 
 Tensor::Tensor(const element::Type& element_type,
                PrimaryTensorView*   primary_tensor_view,
-               const Node*          parent,
-               size_t               value_index)
+               const std::string&   name,
+               bool                 is_output,
+               bool                 is_input)
     : m_element_type(element_type)
     , m_primary_tensor_view(primary_tensor_view)
-    , m_is_output{parent->is_output()}
-    , m_is_input{parent->is_parameter()}
+    , m_is_output{is_output}
+    , m_is_input{is_input}
     , m_is_persistent{false}
-    , m_name{parent->get_node_id() + "_" + std::to_string(value_index)}
+    , m_name{name}
     , m_next_view_id{0}
 {
     size_t size = 1;
@@ -39,6 +40,11 @@ Tensor::Tensor(const element::Type& element_type,
     m_size = size * m_element_type.size();
 }
 
+std::string Tensor::make_tensor_name(const Node* node, size_t value_index)
+{
+    return node->get_node_id() + "_" + std::to_string(value_index);
+}
+
 std::string Tensor::get_next_view_name()
 {
     return m_name + "_TV" + std::to_string(m_next_view_id++);

src/ngraph/descriptor/tensor.hpp

@@ -45,8 +45,9 @@ private:
 
     Tensor(const element::Type& element_type,
            PrimaryTensorView*   tensor_view,
-           const Node*          parent,
-           size_t               value_index);
+           const std::string&   name,
+           bool                 is_output,
+           bool                 is_input);
 
     std::string get_next_view_name();
 
@@ -59,6 +60,8 @@ public:
     void               set_pool_offset(size_t);
     size_t             get_pool_offset() const;
 
+    static std::string make_tensor_name(const Node* node, size_t value_index);
+
 protected:
     const element::Type& m_element_type;
     PrimaryTensorView*   m_primary_tensor_view;

src/ngraph/descriptor/tensor_view.hpp

@@ -14,10 +14,13 @@
 
 #pragma once
 
+#include <memory>
+
 #include "ngraph/descriptor/tensor.hpp"
+#include "ngraph/descriptor/value.hpp"
+#include "ngraph/log.hpp"
 #include "ngraph/shape.hpp"
 #include "ngraph/types/type.hpp"
-#include "ngraph/log.hpp"
 
 namespace ngraph
 {
@@ -25,11 +28,14 @@ namespace ngraph
 
     namespace descriptor
     {
-        class Tensor;
-        class TensorViewLayout;
+        namespace layout
+        {
+            class Tensor;
+            class TensorViewLayout;
+        }
 
-        // Describes a view of an instantiated tensor
-        class TensorView
+        /// @brief Compile-time descriptor of a first-class value that is a view of a tensor.
+        class TensorView : public Value
         {
             TensorView(const TensorView&) = delete;
             TensorView& operator=(const TensorView&) = delete;
@@ -44,6 +50,12 @@ namespace ngraph
             virtual ~TensorView() {}
             virtual const Tensor& get_tensor() const = 0;
             virtual Tensor&       get_tensor()       = 0;
+
+            virtual std::shared_ptr<const ValueType> get_value_type() const override
+            {
+                return m_tensor_view_type;
+            }
+
             const std::string& get_name() const { return m_name; }
 
             std::shared_ptr<const TensorViewType> get_tensor_view_type() const
@@ -51,35 +63,27 @@ namespace ngraph
                 return m_tensor_view_type;
             }
 
-            const std::shared_ptr<TensorViewLayout>& get_tensor_view_layout() const
+            const std::shared_ptr<layout::TensorViewLayout>& get_tensor_view_layout() const
             {
                 return m_tensor_view_layout;
             }
 
-            void set_tensor_view_layout(const std::shared_ptr<TensorViewLayout>& tensor_view_layout)
+            void set_tensor_view_layout(
+                const std::shared_ptr<layout::TensorViewLayout>& tensor_view_layout)
             {
                 m_tensor_view_layout = tensor_view_layout;
             }
 
-        protected:
-            std::shared_ptr<const TensorViewType> m_tensor_view_type;
-            std::shared_ptr<TensorViewLayout>     m_tensor_view_layout;
-            std::string                           m_name;
-        };
-
-        // A PrimaryTensorView owns the tensor. All other views are the result
-        // of some index operation on the primary view.
-        class PrimaryTensorView : public TensorView
-        {
-        public:
-            PrimaryTensorView(const std::shared_ptr<const TensorViewType>& tensor_view_type,
-                const Node* parent, size_t value_index);
-
-            virtual const Tensor& get_tensor() const override;
-            virtual Tensor&       get_tensor() override;
+            virtual void collect_tensor_views(std::vector<std::shared_ptr<TensorView>>& views,
+                                              const std::shared_ptr<Value>& value) const override
+            {
+                views.push_back(std::static_pointer_cast<TensorView>(value));
+            }
 
         protected:
-            Tensor m_tensor;
+            std::shared_ptr<const TensorViewType>     m_tensor_view_type;
+            std::shared_ptr<layout::TensorViewLayout> m_tensor_view_layout;
+            std::string                               m_name;
         };
     }
 }

src/ngraph/descriptor/tuple.cpp

+// ----------------------------------------------------------------------------
+// Copyright 2017 Nervana Systems Inc.
+// 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
+// ----------------------------------------------------------------------------
+
+#include <memory>
+#include <vector>
+
+#include "ngraph/descriptor/tensor_view.hpp"
+#include "ngraph/descriptor/tuple.hpp"
+#include "ngraph/types/type.hpp"
+
+using namespace ngraph::descriptor;
+
+Tuple::Tuple(const std::vector<std::shared_ptr<ngraph::descriptor::Value>>& elements)
+    : m_elements(elements)
+{
+    std::vector<std::shared_ptr<const ngraph::ValueType>> types;
+    for (auto element : m_elements)
+    {
+        types.push_back(element->get_value_type());
+    }
+    m_tuple_type = std::make_shared<ngraph::TupleType>(types);
+}
+
+void Tuple::collect_tensor_views(std::vector<std::shared_ptr<TensorView>>& views,
+                                 const std::shared_ptr<Value>&             value) const
+{
+    for (auto element : m_elements)
+    {
+        element->collect_tensor_views(views, element);
+    }
+}

src/ngraph/descriptor/tuple.hpp

+// ----------------------------------------------------------------------------
+// Copyright 2017 Nervana Systems Inc.
+// 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
+// ----------------------------------------------------------------------------
+
+#pragma once
+
+#include <memory>
+#include <vector>
+
+#include "ngraph/descriptor/value.hpp"
+#include "ngraph/types/type.hpp"
+
+namespace ngraph
+{
+    namespace descriptor
+    {
+        /// @brief Compile-time descriptor of a first-class value that is a tuple of zero or more first-class values.
+        class Tuple : public Value
+        {
+        public:
+            Tuple(const std::vector<std::shared_ptr<ngraph::descriptor::Value>>& elements);
+
+            const std::shared_ptr<ngraph::TupleType> get_tuple_type() const;
+            std::shared_ptr<ngraph::TupleType>       get_tuple_type();
+
+            virtual std::shared_ptr<const ValueType> get_value_type() const override
+            {
+                return m_tuple_type;
+            }
+
+            virtual void collect_tensor_views(std::vector<std::shared_ptr<TensorView>>& views,
+                                              const std::shared_ptr<Value>& value) const override;
+
+        protected:
+            std::shared_ptr<ngraph::TupleType>                      m_tuple_type;
+            std::vector<std::shared_ptr<ngraph::descriptor::Value>> m_elements;
+        };
+    }
+}

src/ngraph/descriptor/value.hpp

+// ----------------------------------------------------------------------------
+// Copyright 2017 Nervana Systems Inc.
+// 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
+// ----------------------------------------------------------------------------
+
+#pragma once
+
+#include <memory>
+
+#include "ngraph/types/type.hpp"
+
+namespace ngraph
+{
+    namespace descriptor
+    {
+        class TensorView;
+
+        /// @brief Compile-time descriptor of a first-class value.
+        class Value
+        {
+        public:
+            virtual ~Value() {}
+            virtual std::shared_ptr<const ngraph::ValueType> get_value_type() const      = 0;
+
+            /// @brief helper for collecting all the tensor views in a sequence of values
+            ///
+            /// @param views The vector of tensor views being collected.
+            /// @param value A shared pointer for this.
+            ///
+            /// Append each tensor view in this value to views. Since this may be a tensor view
+            /// we need to pass a shared pointer to this since we can't get one from this.
+            virtual void collect_tensor_views(std::vector<std::shared_ptr<TensorView>>& views,
+                                              const std::shared_ptr<Value>& value) const = 0;
+        };
+    }
+}

src/ngraph/ngraph.hpp

@@ -18,14 +18,33 @@
 
 #pragma once
 
+/// @namespace ngraph
+/// @brief The Intel Nervana Graph C++ API.
+
+/// @namespace ngraph::descriptor
+/// @brief Descriptors are compile-time representations of objects that will appear at run-time.
+
+/// @namespace ngraph::descriptor::layout
+/// @brief Layout descriptors describe how tensor views are implemented.
+
+/// @namespace ngraph::op
+/// @brief Ops used in graph-building.
+
+/// @namespace ngraph::runtime
+/// @brief The objects used for executing the graph.
+
 #include "ngraph/common.hpp"
 #include "ngraph/descriptor/buffer.hpp"
 #include "ngraph/descriptor/call_frame.hpp"
 #include "ngraph/descriptor/input.hpp"
+#include "ngraph/descriptor/layout/dense_tensor_view_layout.hpp"
+#include "ngraph/descriptor/layout/tensor_view_layout.hpp"
 #include "ngraph/descriptor/output.hpp"
+#include "ngraph/descriptor/primary_tensor_view.hpp"
 #include "ngraph/descriptor/tensor.hpp"
 #include "ngraph/descriptor/tensor_view.hpp"
-#include "ngraph/descriptor/tensor_view_layout.hpp"
+#include "ngraph/descriptor/tuple.hpp"
+#include "ngraph/descriptor/value.hpp"
 #include "ngraph/except.hpp"
 #include "ngraph/function.hpp"
 #include "ngraph/node.hpp"
@@ -41,6 +60,7 @@
 #include "ngraph/ops/equal.hpp"
 #include "ngraph/ops/exp.hpp"
 #include "ngraph/ops/floor.hpp"
+#include "ngraph/ops/get_tuple_element.hpp"
 #include "ngraph/ops/greater.hpp"
 #include "ngraph/ops/less.hpp"
 #include "ngraph/ops/log.hpp"
@@ -56,10 +76,13 @@
 #include "ngraph/ops/select.hpp"
 #include "ngraph/ops/subtract.hpp"
 #include "ngraph/ops/tuple.hpp"
-#include "ngraph/runtime/external_function.hpp"
 #include "ngraph/runtime/call_frame.hpp"
+#include "ngraph/runtime/external_function.hpp"
 #include "ngraph/runtime/instruction.hpp"
+#include "ngraph/runtime/parameterized_tensor_view.hpp"
 #include "ngraph/runtime/tensor_view.hpp"
+#include "ngraph/runtime/tuple.hpp"
+#include "ngraph/runtime/value.hpp"
 #include "ngraph/shape.hpp"
 #include "ngraph/types/element_type.hpp"
 #include "ngraph/types/type.hpp"

src/ngraph/node.cpp

@@ -36,7 +36,7 @@ Node::~Node()
 {
 }
 
-void Node::set_value_type_checked(const shared_ptr<ValueType>& value_type)
+void Node::set_value_type_checked(const shared_ptr<const ValueType>& value_type)
 {
     if (nullptr == m_value_type)
     {
@@ -58,7 +58,7 @@ void Node::assign_tensors()
     size_t i = 0;
     for (auto tvt : tensor_view_types)
     {
-        auto tensor_view_descriptor = make_shared<descriptor::PrimaryTensorView>(tvt, this, i);
+        auto tensor_view_descriptor = make_shared<descriptor::PrimaryTensorView>(tvt, ngraph::descriptor::Tensor::make_tensor_name(this, i), is_output(), is_parameter());
         m_outputs.emplace_back(this, i, tensor_view_descriptor);
         i++;
     }

src/ngraph/node.hpp

@@ -16,8 +16,8 @@
 
 #include <set>
 #include <string>
-#include <vector>
 #include <unordered_set>
+#include <vector>
 
 #include <iostream>
 
@@ -64,7 +64,7 @@ namespace ngraph
         void assign_tensors();
 
         const Nodes& get_arguments() const { return m_arguments; }
-        void clear_arguments() { m_arguments.clear(); }
+        void         clear_arguments() { m_arguments.clear(); }
 
         const std::multiset<Node*>& users() const { return m_users; }
 
@@ -78,15 +78,15 @@ namespace ngraph
             return typeid(*this) == typeid(*node.get());
         }
 
-        std::shared_ptr<ValueType>       get_value_type() { return m_value_type; }
-        const std::shared_ptr<ValueType> get_value_type() const { return m_value_type; }
+        std::shared_ptr<const ValueType>       get_value_type() { return m_value_type; }
+        const std::shared_ptr<const ValueType> get_value_type() const { return m_value_type; }
 
         void set_value_type(const element::Type& element_type, const Shape& shape)
         {
             m_value_type = std::make_shared<TensorViewType>(element_type, shape);
         }
 
-        void set_value_type(const std::shared_ptr<ValueType>& value_type)
+        void set_value_type(const std::shared_ptr<const ValueType>& value_type)
         {
             m_value_type = value_type;
         }
@@ -95,7 +95,7 @@ namespace ngraph
         // value_type agrees with the value type that was set.
         // This is used when the framework specifies a value type for the value, and we
         // independently compute what we thing the value type should be from the arguments.
-        void set_value_type_checked(const std::shared_ptr<ValueType>& value_type);
+        void set_value_type_checked(const std::shared_ptr<const ValueType>& value_type);
 
         bool is_parameter() const;
         bool is_output() const;
@@ -104,9 +104,9 @@ namespace ngraph
         size_t               get_instance_id() const { return m_instance_id; }
         friend std::ostream& operator<<(std::ostream&, const Node&);
 
-        std::vector<descriptor::Input>&  get_inputs() { return m_inputs; }
+        std::vector<descriptor::Input>&        get_inputs() { return m_inputs; }
         const std::vector<descriptor::Input>&  get_inputs() const { return m_inputs; }
-        std::vector<descriptor::Output>& get_outputs() { return m_outputs; }
+        std::vector<descriptor::Output>&       get_outputs() { return m_outputs; }
         const std::vector<descriptor::Output>& get_outputs() const { return m_outputs; }
 
         std::unordered_set<descriptor::Tensor*> liveness_live_list;
@@ -114,14 +114,14 @@ namespace ngraph
         std::unordered_set<descriptor::Tensor*> liveness_free_list;
 
     protected:
-        Nodes                           m_arguments;
-        std::shared_ptr<ValueType>      m_value_type;
-        std::multiset<Node*>            m_users;
-        std::string                     m_name;
-        size_t                          m_instance_id;
-        static size_t                   m_next_instance_id;
-        std::vector<descriptor::Input>  m_inputs;
-        std::vector<descriptor::Output> m_outputs;
-        bool                            m_is_output;
+        Nodes                            m_arguments;
+        std::shared_ptr<const ValueType> m_value_type;
+        std::multiset<Node*>             m_users;
+        std::string                      m_name;
+        size_t                           m_instance_id;
+        static size_t                    m_next_instance_id;
+        std::vector<descriptor::Input>   m_inputs;
+        std::vector<descriptor::Output>  m_outputs;
+        bool                             m_is_output;
     };
 }

src/ngraph/ops/binary_elementwise_builtin.cpp

@@ -29,9 +29,9 @@ void BinaryElementwiseBuiltin::propagate_types()
     }
 
     auto arg0_tensor_type =
-        dynamic_pointer_cast<TensorViewType>(m_arguments.at(0)->get_value_type());
+        dynamic_pointer_cast<const TensorViewType>(m_arguments.at(0)->get_value_type());
     auto arg1_tensor_type =
-        dynamic_pointer_cast<TensorViewType>(m_arguments.at(1)->get_value_type());
+        dynamic_pointer_cast<const TensorViewType>(m_arguments.at(1)->get_value_type());
     if (nullptr == arg0_tensor_type || nullptr == arg1_tensor_type)
     {
         throw ngraph_error("Arguments must be tensor views");

src/ngraph/ops/broadcast.cpp

@@ -28,7 +28,7 @@ void Broadcast::propagate_types()
     {
         throw ngraph_error("Argument to broadcast is missing type.");
     }
-    auto arg_tensor_view_type = dynamic_pointer_cast<TensorViewType>(arg_type);
+    auto arg_tensor_view_type = dynamic_pointer_cast<const TensorViewType>(arg_type);
     if (nullptr == arg_tensor_view_type)
     {
         throw ngraph_error("Argument to broadcast is not a tensor view");

src/ngraph/ops/concatenate.cpp

@@ -32,7 +32,7 @@ void Concat::propagate_types()
         throw ngraph_error("Argument to concat is missing type.");
     }
 
-    auto arg0_tensor_view_type = dynamic_pointer_cast<TensorViewType>(arg0_type);
+    auto arg0_tensor_view_type = dynamic_pointer_cast<const TensorViewType>(arg0_type);
     if (nullptr == arg0_tensor_view_type)
     {
         throw ngraph_error("Argument to concat is not a tensor view");
@@ -55,7 +55,7 @@ void Concat::propagate_types()
             throw ngraph_error("Argument to concat is missing type.");
         }
 
-        auto argi_tensor_view_type = dynamic_pointer_cast<TensorViewType>(argi_type);
+        auto argi_tensor_view_type = dynamic_pointer_cast<const TensorViewType>(argi_type);
         if (nullptr == argi_tensor_view_type)
         {
             throw ngraph_error("Argument to concat is not a tensor view");

src/ngraph/ops/dot.cpp

@@ -22,9 +22,9 @@ using namespace ngraph::op;
 void Dot::propagate_types()
 {
     auto arg0_tensor_type =
-        dynamic_pointer_cast<TensorViewType>(m_arguments.at(0)->get_value_type());
+        dynamic_pointer_cast<const TensorViewType>(m_arguments.at(0)->get_value_type());
     auto arg1_tensor_type =
-        dynamic_pointer_cast<TensorViewType>(m_arguments.at(1)->get_value_type());
+        dynamic_pointer_cast<const TensorViewType>(m_arguments.at(1)->get_value_type());
     if (nullptr == arg0_tensor_type || nullptr == arg1_tensor_type)
     {
         throw ngraph_error("Arguments to dot must be tensor views");

src/ngraph/ops/get_tuple_element.cpp

+// ----------------------------------------------------------------------------
+// Copyright 2017 Nervana Systems Inc.
+// 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
+// ----------------------------------------------------------------------------
+
+#include <sstream>
+
+#include "ngraph/ops/get_tuple_element.hpp"
+
+using namespace std;
+using namespace ngraph::op;
+
+void GetTupleElement::propagate_types()
+{
+    if (m_arguments.size() != 1)
+    {
+        throw ngraph_error("Wrong number of arguments.");
+    }
+
+    auto arg0_tuple_type =
+        dynamic_pointer_cast<const TupleType>(m_arguments.at(0)->get_value_type());
+    if (nullptr == arg0_tuple_type)
+    {
+        throw ngraph_error("Argument must be a tuple view");
+    }
+
+    if (m_n >= arg0_tuple_type->get_element_types().size()){
+        throw ngraph_error("Indexing tuple beyond its size");
+    }
+
+    set_value_type_checked(arg0_tuple_type->get_element_types().at(m_n));
+}

src/ngraph/descriptor/tensor_view_layout.hpp → src/ngraph/ops/get_tuple_element.hpp

@@ -14,27 +14,30 @@
 
 #pragma once
 
-#include <vector>
+#include "ngraph/ops/op.hpp"
 
 namespace ngraph
 {
-    namespace descriptor
+    namespace op
     {
-        // An interface for describing implementations of tensor views
-        // Kernel selection will need to pay attention to the layout
-        class TensorViewLayout
+        class Node;
+
+        class GetTupleElement : public Builtin
         {
         public:
-            virtual ~TensorViewLayout() {}
-        };
+            GetTupleElement(const std::shared_ptr<Node>& arg, size_t n)
+                : Builtin({arg})
+                , m_n{n}
+            {
+            }
+
+            virtual void        propagate_types() override;
+            virtual std::string description() const override { return "GetTupleElement"; }
+
+            size_t get_n() const { return m_n; }
 
-        // The standard strided layout
-        class DenseTensorViewLayout : public TensorViewLayout
-        {
         protected:
-            std::shared_ptr<Buffer> m_buffer;
-            Strides                 m_strides;
-            size_t                  m_offset;
+            size_t m_n;
         };
     }
 }

src/ngraph/ops/select.cpp

@@ -29,11 +29,11 @@ void Select::propagate_types()
     }
 
     auto arg0_tensor_type =
-        dynamic_pointer_cast<TensorViewType>(m_arguments.at(0)->get_value_type());
+        dynamic_pointer_cast<const TensorViewType>(m_arguments.at(0)->get_value_type());
     auto arg1_tensor_type =
-        dynamic_pointer_cast<TensorViewType>(m_arguments.at(1)->get_value_type());
+        dynamic_pointer_cast<const TensorViewType>(m_arguments.at(1)->get_value_type());
     auto arg2_tensor_type =
-        dynamic_pointer_cast<TensorViewType>(m_arguments.at(2)->get_value_type());
+        dynamic_pointer_cast<const TensorViewType>(m_arguments.at(2)->get_value_type());
     if (nullptr == arg0_tensor_type || nullptr == arg1_tensor_type || nullptr == arg2_tensor_type)
     {
         throw ngraph_error("Arguments must be tensor views");

src/ngraph/ops/tuple.cpp

@@ -13,6 +13,7 @@
 // ----------------------------------------------------------------------------
 
 #include <memory>
+#include <vector>
 
 #include "ngraph/ngraph.hpp"
 
@@ -21,5 +22,10 @@ using namespace ngraph::op;
 
 void Tuple::propagate_types()
 {
-    throw ngraph_error("NIY");
+    vector<shared_ptr<const ValueType>> element_types;
+    for (auto argument : m_arguments)
+    {
+        element_types.push_back(argument->get_value_type());
+    }
+    set_value_type_checked(make_shared<TupleType>(element_types));
 }

src/ngraph/ops/unary_elementwise_builtin.cpp

@@ -28,7 +28,7 @@ void UnaryElementwiseBuiltin::propagate_types()
     }
 
     auto arg_tensor_type =
-        dynamic_pointer_cast<TensorViewType>(m_arguments.at(0)->get_value_type());
+        dynamic_pointer_cast<const TensorViewType>(m_arguments.at(0)->get_value_type());
     if (nullptr == arg_tensor_type)
     {
         throw ngraph_error("Argument must be tensor view");

src/ngraph/runtime/call_frame.cpp

@@ -35,8 +35,9 @@ CallFrame::CallFrame(size_t
     copy(temps.begin(), temps.end(), m_tensors.begin() + m_n_inputs + m_n_outputs);
 }
 
-void CallFrame::operator()(const std::vector<std::shared_ptr<ngraph::runtime::TensorView>>& inputs,
-                           const std::vector<std::shared_ptr<ngraph::runtime::TensorView>>& outputs)
+void CallFrame::tensor_call(
+    const std::vector<std::shared_ptr<ngraph::runtime::TensorView>>& inputs,
+    const std::vector<std::shared_ptr<ngraph::runtime::TensorView>>& outputs)
 {
     copy(inputs.begin(), inputs.end(), m_tensors.begin());
     copy(outputs.begin(), outputs.end(), m_tensors.begin() + m_n_inputs);
@@ -51,3 +52,20 @@ void CallFrame::operator()(const std::vector<std::shared_ptr<ngraph::runtime::Te
     // Don't hold onto inputs/outputs
     fill_n(m_tensors.begin(), m_n_inputs + m_n_outputs, nullptr);
 }
+
+void CallFrame::operator()(const std::vector<std::shared_ptr<ngraph::runtime::Value>>& arguments,
+                           const std::vector<std::shared_ptr<ngraph::runtime::Value>>& results)
+{
+    // TODO: Check types of args and result
+    std::vector<std::shared_ptr<ngraph::runtime::TensorView>> inputs;
+    for (auto argument : arguments){
+        argument->collect_tensor_views(inputs, argument);
+    }
+
+    std::vector<std::shared_ptr<ngraph::runtime::TensorView>> outputs;
+    for (auto result : results){
+        result->collect_tensor_views(outputs, result);
+    }
+
+    tensor_call(inputs, outputs);
+}

src/ngraph/runtime/call_frame.hpp

@@ -38,9 +38,19 @@ namespace ngraph
                 size_t                                                            initial_pc,
                 const std::shared_ptr<std::vector<std::shared_ptr<Instruction>>>& instructions);
 
-            void                        operator()(const std::vector<std::shared_ptr<ngraph::runtime::TensorView>>& inputs,
-                                                   const std::vector<std::shared_ptr<ngraph::runtime::TensorView>>& outpus);
-            void                        set_return() { m_return = true; }
+            /// @brief Invoke the function with values matching the signature of the function.
+            ///
+            /// Tuples will be expanded into their tensor views to build the call frame.
+            void operator()(const std::vector<std::shared_ptr<ngraph::runtime::Value>>& inputs,
+                            const std::vector<std::shared_ptr<ngraph::runtime::Value>>& outpus);
+
+            /// @brief Invoke the function with tuples pre-expanded to their underlying tensor views.
+            void tensor_call(
+                const std::vector<std::shared_ptr<ngraph::runtime::TensorView>>& inputs,
+                const std::vector<std::shared_ptr<ngraph::runtime::TensorView>>& outpus);
+
+            void set_return() { m_return = true; }
+
             std::shared_ptr<TensorView> get_tensor(size_t i) { return m_tensors[i]; }
 
             template <typename ET>

src/ngraph/runtime/eigen/copy.hpp

+// ----------------------------------------------------------------------------
+// Copyright 2017 Nervana Systems Inc.
+// 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
+// ----------------------------------------------------------------------------
+
+#pragma once
+
+#include <cassert>
+
+#include "ngraph/runtime/call_frame.hpp"
+#include "ngraph/runtime/eigen/utils.hpp"
+#include "ngraph/runtime/instruction.hpp"
+#include "ngraph/runtime/tensor_view.hpp"
+
+namespace ngraph
+{
+    namespace runtime
+    {
+        namespace eigen
+        {
+            /// @brief Copies a tensor from in to out.
+            template <typename ET>
+            class CopyInstruction : public Instruction
+            {
+            public:
+                /// @param in Index of input tensor in call frame.
+                /// @param out Index of output tensor in call frame.
+                CopyInstruction(size_t in, size_t out)
+                    : m_in(in)
+                    , m_out(out)
+                {
+                }
+
+                virtual void execute(CallFrame& call_frame) const override
+                {
+                    call_frame.get_parameterized_tensor<ET>(m_out)->get_vector() =
+                        call_frame.get_parameterized_tensor<ET>(m_in)->get_vector();
+                }
+
+            protected:
+                size_t m_in;
+                size_t m_out;
+            };
+        }
+    }
+}

src/ngraph/runtime/parameterized_tensor_view.hpp

+// ----------------------------------------------------------------------------
+// Copyright 2017 Nervana Systems Inc.
+// 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
+// ----------------------------------------------------------------------------
+
+#pragma once
+
+#include <memory>
+#include <vector>
+
+#include "ngraph/descriptor/layout/dense_tensor_view_layout.hpp"
+#include "ngraph/descriptor/primary_tensor_view.hpp"
+#include "ngraph/runtime/tensor_view.hpp"
+#include "ngraph/shape.hpp"
+#include "ngraph/types/element_type.hpp"
+
+namespace ngraph
+{
+    namespace runtime
+    {
+        template <typename ET>
+        class ParameterizedTensorView : public TensorView
+        {
+        public:
+            /// Create a tensor
+            ParameterizedTensorView(const ngraph::Shape& shape)
+                : TensorView(std::make_shared<ngraph::descriptor::PrimaryTensorView>(
+                      std::make_shared<ngraph::TensorViewType>(ET::element_type(), shape),
+                      "external",
+                      true,
+                      true))
+            {
+                m_descriptor->set_tensor_view_layout(
+                    std::make_shared<ngraph::descriptor::layout::DenseTensorViewLayout>(
+                        *m_descriptor));
+                m_vector.resize(m_descriptor->get_tensor_view_layout()->get_size());
+            }
+
+            ParameterizedTensorView(
+                const std::shared_ptr<ngraph::descriptor::TensorView>& descriptor);
+
+            using element_type = ET;
+            using value_type   = typename ET::type;
+            using storage_type = std::vector<value_type>;
+
+            template <typename T>
+            ParameterizedTensorView<ET>& operator=(const std::vector<T>& value)
+            {
+                get_vector() = value;
+                return *this;
+            }
+
+            // For getting the data out
+            storage_type& get_vector() { return m_vector; }
+
+        protected:
+            storage_type m_vector;
+        };
+    }
+}

src/ngraph/runtime/tensor_view.hpp

@@ -17,6 +17,8 @@
 #include <memory>
 #include <vector>
 
+#include "ngraph/descriptor/tensor_view.hpp"
+#include "ngraph/runtime/value.hpp"
 #include "ngraph/shape.hpp"
 #include "ngraph/types/element_type.hpp"
 
@@ -27,58 +29,45 @@ namespace ngraph
         template <typename ET>
         class ParameterizedTensorView;
 
-        class TensorView
+        class TensorView : public Value
         {
+        protected:
+            TensorView(const std::shared_ptr<ngraph::descriptor::TensorView>& descriptor)
+                : m_descriptor(descriptor)
+            {
+            }
+
         public:
+            TensorView() {}
+
             virtual ~TensorView() {}
+
             template <typename ET>
             ParameterizedTensorView<ET>* get_parameterized_tensor()
             {
                 return dynamic_cast<ParameterizedTensorView<ET>*>(this);
             }
-        };
 
-        template <typename ET>
-        class ParameterizedTensorView : public ngraph::runtime::TensorView
-        {
-        public:
-            ParameterizedTensorView(const ngraph::Shape& shape)
-                : m_vector(ngraph::shape_size(shape), 0)
-                , m_shape(shape)
+            std::shared_ptr<const ngraph::descriptor::TensorView> get_tensor_view_descriptor() const
             {
+                return m_descriptor;
             }
 
-            virtual ~ParameterizedTensorView() {}
-
-            // Standard definitions from vector
-            using element_type           = ET;
-            using value_type             = typename ET::type;
-            using storage_type           = std::vector<value_type>;
-            using size_type              = typename storage_type::size_type;
-            using difference_type        = typename storage_type::difference_type;
-            using reference              = typename storage_type::reference;
-            using const_reference        = typename storage_type::const_reference;
-            using pointer                = typename storage_type::pointer;
-            using const_pointer          = typename storage_type::const_pointer;
-            using iterator               = typename storage_type::iterator;
-            using const_iterator         = typename storage_type::const_iterator;
-            using reverse_iterator       = typename storage_type::reverse_iterator;
-            using const_reverse_iterator = typename storage_type::const_reverse_iterator;
+            virtual std::shared_ptr<ngraph::descriptor::Value> get_descriptor() const override
+            {
+                return m_descriptor;
+            }
 
-            template <typename T>
-            ParameterizedTensorView<ET>& operator=(const std::vector<T>& value)
+            virtual void collect_tensor_views(std::vector<std::shared_ptr<TensorView>>& views,
+                                              const std::shared_ptr<Value>& value) const override
             {
-                get_vector() = value;
-                return *this;
+                views.push_back(std::static_pointer_cast<TensorView>(value));
             }
 
-            // For getting the data out
-            storage_type& get_vector() { return m_vector; }
-            const ngraph::Shape& get_shape() const { return m_shape; }
+            const Shape& get_shape() { return m_descriptor->get_tensor_view_type()->get_shape(); }
 
         protected:
-            storage_type m_vector;
-            ngraph::Shape m_shape;
+            std::shared_ptr<ngraph::descriptor::TensorView> m_descriptor;
         };
     }
 }

src/ngraph/runtime/tuple.cpp

+// ----------------------------------------------------------------------------
+// Copyright 2017 Nervana Systems Inc.
+// 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
+// ----------------------------------------------------------------------------
+
+#include <memory>
+#include <vector>
+
+#include "ngraph/descriptor/tuple.hpp"
+#include "ngraph/runtime/tensor_view.hpp"
+#include "ngraph/runtime/tuple.hpp"
+
+using namespace ngraph::runtime;
+
+Tuple::Tuple(const std::vector<std::shared_ptr<ngraph::runtime::Value>>& elements)
+    : m_elements(elements)
+{
+    std::vector<std::shared_ptr<ngraph::descriptor::Value>> descriptors;
+    for (auto element : m_elements)
+    {
+        descriptors.push_back(element->get_descriptor());
+    }
+    m_descriptor = std::make_shared<ngraph::descriptor::Tuple>(descriptors);
+}
+
+void Tuple::collect_tensor_views(std::vector<std::shared_ptr<TensorView>>& views,
+                                 const std::shared_ptr<Value>&        value) const
+{
+    for (auto element : m_elements)
+    {
+        element->collect_tensor_views(views, element);
+    }
+}

src/ngraph/runtime/tuple.hpp

+// ----------------------------------------------------------------------------
+// Copyright 2017 Nervana Systems Inc.
+// 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
+// ----------------------------------------------------------------------------
+
+#pragma once
+
+#include <memory>
+#include <vector>
+
+#include "ngraph/descriptor/tuple.hpp"
+#include "ngraph/runtime/value.hpp"
+
+namespace ngraph
+{
+    namespace runtime
+    {
+        /// @brief A first-class value holding zero or more first-class values.
+        class Tuple : public Value
+        {
+        public:
+            Tuple(const std::vector<std::shared_ptr<ngraph::runtime::Value>>& elements);
+
+            virtual std::shared_ptr<ngraph::descriptor::Value> get_descriptor() const override
+            {
+                return m_descriptor;
+            }
+
+            std::shared_ptr<const ngraph::descriptor::Value> get_tuple_descriptor() const
+            {
+                return m_descriptor;
+            }
+
+            virtual void
+                collect_tensor_views(std::vector<std::shared_ptr<TensorView>>& views,
+                                     const std::shared_ptr<Value>& value) const override;
+
+        protected:
+            std::vector<std::shared_ptr<Value>>        m_elements;
+            std::shared_ptr<ngraph::descriptor::Tuple> m_descriptor;
+        };
+    }
+}

src/ngraph/runtime/utils.cpp

+// ----------------------------------------------------------------------------
+// Copyright 2017 Nervana Systems Inc.
+// 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
+// ----------------------------------------------------------------------------
+
+#include "ngraph/runtime/utils.hpp"
+
+std::shared_ptr<ngraph::runtime::Tuple> ngraph::runtime::make_tuple(
+    const std::vector<std::shared_ptr<ngraph::runtime::Value>>& elements)
+{
+    return std::make_shared<ngraph::runtime::Tuple>(elements);
+}

src/ngraph/runtime/utils.hpp

@@ -15,20 +15,28 @@
 #pragma once
 
 #include <memory>
+#include <vector>
 
 #include "ngraph/runtime/call_frame.hpp"
-#include "ngraph/runtime/tensor_view.hpp"
+#include "ngraph/runtime/parameterized_tensor_view.hpp"
+#include "ngraph/runtime/tuple.hpp"
+#include "ngraph/runtime/value.hpp"
 #include "ngraph/types/element_type.hpp"
 
 namespace ngraph
 {
     namespace runtime
     {
+        /// @brief Framework constructor of a tensor of a specific element type and shape.
         template <typename ET>
         std::shared_ptr<ngraph::runtime::ParameterizedTensorView<ET>>
             make_tensor(const Shape& shape)
         {
             return std::make_shared<runtime::ParameterizedTensorView<ET>>(shape);
         }
+
+        /// @brief Framework constructor of a tuple from a sequence of values.
+        std::shared_ptr<ngraph::runtime::Tuple>
+            make_tuple(const std::vector<std::shared_ptr<ngraph::runtime::Value>>& elements);
     }
 }

src/ngraph/runtime/value.hpp

+// ----------------------------------------------------------------------------
+// Copyright 2017 Nervana Systems Inc.
+// 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
+// ----------------------------------------------------------------------------
+
+#pragma once
+
+#include <memory>
+#include <vector>
+
+#include "ngraph/descriptor/value.hpp"
+
+namespace ngraph
+{
+    namespace runtime
+    {
+        class TensorView;
+        
+        /// @brief A first-class runtime value.
+        class Value
+        {
+        public:
+            virtual ~Value() {}
+
+            /// @brief The compile-time descriptor for this value.
+            virtual std::shared_ptr<ngraph::descriptor::Value> get_descriptor() const         = 0;
+
+                        /// @brief helper for collecting all the tensor views in a sequence of values
+            ///
+            /// @param views The vector of tensor views being collected.
+            /// @param value A shared pointer for this.
+            ///
+            /// Append each tensor view in this value to views. Since this may be a tensor view
+            /// we need to pass a shared pointer to this since we can't get one from this.
+            virtual void collect_tensor_views(std::vector<std::shared_ptr<TensorView>>& views,
+                                              const std::shared_ptr<Value>& value) const = 0;
+        };
+    }
+}

src/ngraph/types/type.hpp

@@ -82,16 +82,16 @@ namespace ngraph
         TupleType() {}
 
         /// @param element_types A vector of types for the tuple elements
-        TupleType(const std::vector<std::shared_ptr<ValueType>>& element_types)
+        TupleType(const std::vector<std::shared_ptr<const ValueType>>& element_types)
             : m_element_types(element_types)
         {
         }
 
-        const std::vector<std::shared_ptr<ValueType>> get_element_types() const
+        const std::vector<std::shared_ptr<const ValueType>> get_element_types() const
         {
             return m_element_types;
         }
-        std::vector<std::shared_ptr<ValueType>> set_element_types() { return m_element_types; }
+        std::vector<std::shared_ptr<const ValueType>> set_element_types() { return m_element_types; }
 
         virtual bool operator==(const ValueType& that) const override;
         virtual void collect_tensor_views(
@@ -99,6 +99,6 @@ namespace ngraph
         friend std::ostream& operator<<(std::ostream&, const TupleType&);
 
     protected:
-        std::vector<std::shared_ptr<ValueType>> m_element_types;
+        std::vector<std::shared_ptr<const ValueType>> m_element_types;
     };
 }

test/input_output_assign.cpp

@@ -44,7 +44,7 @@ TEST(input_output, param_tuple)
     // Same as param_tensor, but for a tuple
     auto tv_tp_0 = make_shared<TensorViewType>(element::Float32::element_type(), Shape{2, 4});
     auto tv_tp_1 = make_shared<TensorViewType>(element::Float32::element_type(), Shape{2, 4, 6});
-    auto tp_tp = make_shared<TupleType>(std::vector<std::shared_ptr<ValueType>>{tv_tp_0, tv_tp_1});
+    auto tp_tp = make_shared<TupleType>(ValueTypes{tv_tp_0, tv_tp_1});
     auto param = make_shared<op::Parameter>(tp_tp);
     param->propagate_types();
     param->assign_tensors();