COMPMID-1603: Add PadLayer to graph API

Change-Id: Ic985ac8b0b09c3a6b3f2d43274af8ce89f8c90dd
Reviewed-on: https://eu-gerrit-1.euhpc.arm.com/150313
Reviewed-by: Georgios Pinitas <georgios.pinitas@arm.com>
Tested-by: bsgcomp <bsgcomp@arm.com>
diff --git a/arm_compute/graph/GraphBuilder.h b/arm_compute/graph/GraphBuilder.h
index 1302d2a..2170cd1 100644
--- a/arm_compute/graph/GraphBuilder.h
+++ b/arm_compute/graph/GraphBuilder.h
@@ -251,6 +251,17 @@
      */
     static NodeID add_normalize_planar_yuv_node(Graph &g, NodeParams params, NodeIdxPair input,
                                                 ITensorAccessorUPtr mean_accessor = nullptr, ITensorAccessorUPtr std_accessor = nullptr);
+    /** Adds a pad layer node to the graph
+     *
+     * @param[in] g       Graph to add the node to
+     * @param[in] params  Common node parameters
+     * @param[in] input   Input to the reshape layer node as a NodeID-Index pair
+     * @param[in] padding The padding for each spatial dimension of the input tensor. The pair padding[i]
+     *                    specifies the front and the end padding in the i-th dimension.
+     *
+     * @return Node ID of the created node, EmptyNodeID in case of error
+     */
+    static NodeID add_pad_node(Graph &g, NodeParams params, NodeIdxPair input, PaddingList padding);
     /** Adds a permute layer node to the graph
      *
      * @param[in] g      Graph to add the node to
diff --git a/arm_compute/graph/TypePrinter.h b/arm_compute/graph/TypePrinter.h
index b0d0fb0..9cdd7b7 100644
--- a/arm_compute/graph/TypePrinter.h
+++ b/arm_compute/graph/TypePrinter.h
@@ -98,6 +98,9 @@
         case NodeType::NormalizePlanarYUVLayer:
             os << "NormalizePlanarYUVLayer";
             break;
+        case NodeType::PadLayer:
+            os << "PadLayer";
+            break;
         case NodeType::PermuteLayer:
             os << "PermuteLayer";
             break;
diff --git a/arm_compute/graph/Types.h b/arm_compute/graph/Types.h
index 1f25209..a1b077a 100644
--- a/arm_compute/graph/Types.h
+++ b/arm_compute/graph/Types.h
@@ -142,6 +142,7 @@
     FullyConnectedLayer,
     NormalizationLayer,
     NormalizePlanarYUVLayer,
+    PadLayer,
     PermuteLayer,
     PoolingLayer,
     ReorgLayer,
diff --git a/arm_compute/graph/backends/FunctionHelpers.h b/arm_compute/graph/backends/FunctionHelpers.h
index 32ef0aa..56f4173 100644
--- a/arm_compute/graph/backends/FunctionHelpers.h
+++ b/arm_compute/graph/backends/FunctionHelpers.h
@@ -659,6 +659,42 @@
     return std::move(func);
 }
 
+/** Create a backend pad layer function
+ *
+ * @tparam PadLayerFunction Backend pad function
+ * @tparam TargetInfo       Target-specific information
+ *
+ * @param[in] node Node to create the backend function for
+ *
+ * @return Backend pad layer function
+ */
+template <typename PadLayerFunction, typename TargetInfo>
+std::unique_ptr<IFunction> create_pad_layer(PadLayerNode &node)
+{
+    validate_node<TargetInfo>(node, 1 /* expected inputs */, 1 /* expected outputs */);
+
+    // Extract IO and info
+    typename TargetInfo::TensorType *input   = get_backing_tensor<TargetInfo>(node.input(0));
+    typename TargetInfo::TensorType *output  = get_backing_tensor<TargetInfo>(node.output(0));
+    const PaddingList               &padding = node.padding();
+    ARM_COMPUTE_ERROR_ON(input == nullptr);
+    ARM_COMPUTE_ERROR_ON(output == nullptr);
+
+    // Create and configure function
+    auto func = support::cpp14::make_unique<PadLayerFunction>();
+    func->configure(input, output, padding);
+
+    // Log info
+    ARM_COMPUTE_LOG_GRAPH_INFO("Instantiated " << node.type()
+                               << " Target " << TargetInfo::TargetType
+                               << " Data Type: " << input->info()->data_type()
+                               << " Input shape: " << input->info()->tensor_shape()
+                               << " Output shape: " << output->info()->tensor_shape()
+                               << std::endl);
+
+    return std::move(func);
+}
+
 /** Create a backend permute layer function
  *
  * @tparam PermuteLayerFunction Backend permute function
diff --git a/arm_compute/graph/backends/ValidateHelpers.h b/arm_compute/graph/backends/ValidateHelpers.h
index ff644c4..b0395da 100644
--- a/arm_compute/graph/backends/ValidateHelpers.h
+++ b/arm_compute/graph/backends/ValidateHelpers.h
@@ -203,6 +203,30 @@
     // Validate function
     return NormalizePlanarYUVLayer::validate(input, output, mean, std);
 }
+
+/** Validates a pad layer node
+ *
+ * @tparam PadLayer Pad layer type
+ *
+ * @param[in] node Node to validate
+ *
+ * @return Status
+ */
+template <typename PadLayer>
+Status validate_pad_layer(PadLayerNode &node)
+{
+    ARM_COMPUTE_LOG_GRAPH_VERBOSE("Validating PadLayer node with ID : " << node.id() << " and Name: " << node.name() << std::endl);
+    ARM_COMPUTE_RETURN_ERROR_ON(node.num_inputs() != 1);
+    ARM_COMPUTE_RETURN_ERROR_ON(node.num_outputs() != 1);
+
+    // Extract IO and info
+    arm_compute::ITensorInfo *input   = get_backing_tensor_info(node.input(0));
+    arm_compute::ITensorInfo *output  = get_backing_tensor_info(node.output(0));
+    const PaddingList        &padding = node.padding();
+
+    return PadLayer::validate(input, output, padding);
+}
+
 /** Validates a permute layer node
  *
  * @tparam PermuteLayer Permute layer type
diff --git a/arm_compute/graph/frontend/Layers.h b/arm_compute/graph/frontend/Layers.h
index 9c1ef1e..d72f549 100644
--- a/arm_compute/graph/frontend/Layers.h
+++ b/arm_compute/graph/frontend/Layers.h
@@ -569,6 +569,31 @@
     ITensorAccessorUPtr _std;
 };
 
+/** Pad Layer */
+class PadLayer final : public ILayer
+{
+public:
+    /** Construct a pad layer.
+     *
+     * @param[in] padding The padding for each spatial dimension of the input tensor. The pair padding[i]
+     *                    specifies the front and the end padding in the i-th dimension.
+     */
+    PadLayer(PaddingList padding)
+        : _padding(padding)
+    {
+    }
+
+    NodeID create_layer(IStream &s) override
+    {
+        NodeParams  common_params = { name(), s.hints().target_hint };
+        NodeIdxPair input         = { s.tail_node(), 0 };
+        return GraphBuilder::add_pad_node(s.graph(), common_params, input, _padding);
+    }
+
+private:
+    PaddingList _padding;
+};
+
 /** Permute Layer */
 class PermuteLayer final : public ILayer
 {
diff --git a/arm_compute/graph/nodes/Nodes.h b/arm_compute/graph/nodes/Nodes.h
index 2bda7e0..4e2a49d 100644
--- a/arm_compute/graph/nodes/Nodes.h
+++ b/arm_compute/graph/nodes/Nodes.h
@@ -40,6 +40,7 @@
 #include "arm_compute/graph/nodes/NormalizationLayerNode.h"
 #include "arm_compute/graph/nodes/NormalizePlanarYUVLayerNode.h"
 #include "arm_compute/graph/nodes/OutputNode.h"
+#include "arm_compute/graph/nodes/PadLayerNode.h"
 #include "arm_compute/graph/nodes/PermuteLayerNode.h"
 #include "arm_compute/graph/nodes/PoolingLayerNode.h"
 #include "arm_compute/graph/nodes/ReorgLayerNode.h"
diff --git a/arm_compute/graph/nodes/NodesFwd.h b/arm_compute/graph/nodes/NodesFwd.h
index ae5ed7c..7aed471 100644
--- a/arm_compute/graph/nodes/NodesFwd.h
+++ b/arm_compute/graph/nodes/NodesFwd.h
@@ -46,6 +46,7 @@
 class NormalizationLayerNode;
 class NormalizePlanarYUVLayerNode;
 class OutputNode;
+class PadLayerNode;
 class PermuteLayerNode;
 class PoolingLayerNode;
 class ReorgLayerNode;
diff --git a/arm_compute/graph/nodes/PadLayerNode.h b/arm_compute/graph/nodes/PadLayerNode.h
new file mode 100644
index 0000000..a14be02
--- /dev/null
+++ b/arm_compute/graph/nodes/PadLayerNode.h
@@ -0,0 +1,60 @@
+/*
+ * Copyright (c) 2018 ARM Limited.
+ *
+ * SPDX-License-Identifier: MIT
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+#ifndef __ARM_COMPUTE_GRAPH_PAD_LAYER_NODE_H__
+#define __ARM_COMPUTE_GRAPH_PAD_LAYER_NODE_H__
+
+#include "arm_compute/graph/INode.h"
+
+namespace arm_compute
+{
+namespace graph
+{
+/** Pad Layer node */
+class PadLayerNode final : public INode
+{
+public:
+    /** Constructor
+     *
+     * @param[in] padding The padding for each spatial dimension of the input tensor. The pair padding[i]
+     *                    specifies the front and the end padding in the i-th dimension.
+     */
+    PadLayerNode(PaddingList &padding);
+    /** Padding list accessor
+     *
+     * @return Padding list
+     */
+    const PaddingList &padding() const;
+
+    // Inherited overridden methods:
+    NodeType         type() const override;
+    bool             forward_descriptors() override;
+    TensorDescriptor configure_output(size_t idx) const override;
+    void accept(INodeVisitor &v) override;
+
+private:
+    PaddingList _padding;
+};
+} // namespace graph
+} // namespace arm_compute
+#endif /* __ARM_COMPUTE_GRAPH_PAD_LAYER_NODE_H__ */
diff --git a/src/graph/GraphBuilder.cpp b/src/graph/GraphBuilder.cpp
index b3879d2..7e51150 100644
--- a/src/graph/GraphBuilder.cpp
+++ b/src/graph/GraphBuilder.cpp
@@ -449,6 +449,11 @@
     return norm_planar_yuv_nid;
 }
 
+NodeID GraphBuilder::add_pad_node(Graph &g, NodeParams params, NodeIdxPair input, PaddingList padding)
+{
+    return create_simple_single_input_output_node<PadLayerNode>(g, params, input, padding);
+}
+
 NodeID GraphBuilder::add_permute_node(Graph &g, NodeParams params, NodeIdxPair input, PermutationVector perm, DataLayout layout)
 {
     return create_simple_single_input_output_node<PermuteLayerNode>(g, params, input, perm, layout);
diff --git a/src/graph/backends/CL/CLFunctionsFactory.cpp b/src/graph/backends/CL/CLFunctionsFactory.cpp
index bd908c1..43fe706 100644
--- a/src/graph/backends/CL/CLFunctionsFactory.cpp
+++ b/src/graph/backends/CL/CLFunctionsFactory.cpp
@@ -103,6 +103,8 @@
             return detail::create_normalization_layer<CLNormalizationLayer, CLTargetInfo>(*polymorphic_downcast<NormalizationLayerNode *>(node), ctx);
         case NodeType::NormalizePlanarYUVLayer:
             return detail::create_normalize_planar_yuv_layer<CLNormalizePlanarYUVLayer, CLTargetInfo>(*polymorphic_downcast<NormalizePlanarYUVLayerNode *>(node));
+        case NodeType::PadLayer:
+            return detail::create_pad_layer<CLPadLayer, CLTargetInfo>(*polymorphic_downcast<PadLayerNode *>(node));
         case NodeType::PermuteLayer:
             return detail::create_permute_layer<CLPermute, CLTargetInfo>(*polymorphic_downcast<PermuteLayerNode *>(node));
         case NodeType::PoolingLayer:
diff --git a/src/graph/backends/CL/CLNodeValidator.cpp b/src/graph/backends/CL/CLNodeValidator.cpp
index a91efce..5f6fa0a 100644
--- a/src/graph/backends/CL/CLNodeValidator.cpp
+++ b/src/graph/backends/CL/CLNodeValidator.cpp
@@ -59,6 +59,8 @@
                    CLDepthwiseConvolutionLayer3x3>(*polymorphic_downcast<DepthwiseConvolutionLayerNode *>(node));
         case NodeType::NormalizePlanarYUVLayer:
             return detail::validate_normalize_planar_yuv_layer<CLNormalizePlanarYUVLayer>(*polymorphic_downcast<NormalizePlanarYUVLayerNode *>(node));
+        case NodeType::PadLayer:
+            return detail::validate_pad_layer<CLPadLayer>(*polymorphic_downcast<PadLayerNode *>(node));
         case NodeType::PermuteLayer:
             return detail::validate_permute_layer<CLPermute>(*polymorphic_downcast<PermuteLayerNode *>(node));
         case NodeType::ReorgLayer:
diff --git a/src/graph/backends/GLES/GCNodeValidator.cpp b/src/graph/backends/GLES/GCNodeValidator.cpp
index 17dc583..1a8876a 100644
--- a/src/graph/backends/GLES/GCNodeValidator.cpp
+++ b/src/graph/backends/GLES/GCNodeValidator.cpp
@@ -113,6 +113,8 @@
             return ARM_COMPUTE_CREATE_ERROR(arm_compute::ErrorCode::RUNTIME_ERROR, "Unsupported operation : FlattenLayer");
         case NodeType::NormalizePlanarYUVLayer:
             return detail::validate_normalize_planar_yuv_layer<GCNormalizePlanarYUVLayer>(*polymorphic_downcast<NormalizePlanarYUVLayerNode *>(node));
+        case NodeType::PadLayer:
+            return ARM_COMPUTE_CREATE_ERROR(arm_compute::ErrorCode::RUNTIME_ERROR, "Unsupported operation : PadLayer");
         case NodeType::PermuteLayer:
             return ARM_COMPUTE_CREATE_ERROR(arm_compute::ErrorCode::RUNTIME_ERROR, "Unsupported operation : PermuteLayer");
         case NodeType::ReorgLayer:
diff --git a/src/graph/backends/NEON/NENodeValidator.cpp b/src/graph/backends/NEON/NENodeValidator.cpp
index 0bc3339..4f35298 100644
--- a/src/graph/backends/NEON/NENodeValidator.cpp
+++ b/src/graph/backends/NEON/NENodeValidator.cpp
@@ -59,6 +59,8 @@
                    NEDepthwiseConvolutionLayer3x3>(*polymorphic_downcast<DepthwiseConvolutionLayerNode *>(node));
         case NodeType::NormalizePlanarYUVLayer:
             return ARM_COMPUTE_CREATE_ERROR(arm_compute::ErrorCode::RUNTIME_ERROR, "Unsupported operation : NormalizePlanarYUVLayer");
+        case NodeType::PadLayer:
+            return ARM_COMPUTE_CREATE_ERROR(arm_compute::ErrorCode::RUNTIME_ERROR, "Unsupported operation : PadLayer");
         case NodeType::PermuteLayer:
             return detail::validate_permute_layer<NEPermute>(*polymorphic_downcast<PermuteLayerNode *>(node));
         case NodeType::ReorgLayer:
diff --git a/src/graph/nodes/PadLayerNode.cpp b/src/graph/nodes/PadLayerNode.cpp
new file mode 100644
index 0000000..e7996d2
--- /dev/null
+++ b/src/graph/nodes/PadLayerNode.cpp
@@ -0,0 +1,87 @@
+/*
+ * Copyright (c) 2018 ARM Limited.
+ *
+ * SPDX-License-Identifier: MIT
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+#include "arm_compute/graph/nodes/PadLayerNode.h"
+
+#include "arm_compute/graph/Graph.h"
+#include "arm_compute/graph/INodeVisitor.h"
+
+#include "arm_compute/core/Helpers.h"
+
+namespace arm_compute
+{
+namespace graph
+{
+PadLayerNode::PadLayerNode(PaddingList &padding)
+    : _padding(padding)
+{
+    _input_edges.resize(1, EmptyEdgeID);
+    _outputs.resize(1, NullTensorID);
+}
+
+const PaddingList &PadLayerNode::padding() const
+{
+    return _padding;
+}
+
+bool PadLayerNode::forward_descriptors()
+{
+    if((input_id(0) != NullTensorID) && (output_id(0) != NullTensorID))
+    {
+        Tensor *dst = output(0);
+        ARM_COMPUTE_ERROR_ON(dst == nullptr);
+        dst->desc() = configure_output(0);
+        return true;
+    }
+    return false;
+}
+
+TensorDescriptor PadLayerNode::configure_output(size_t idx) const
+{
+    ARM_COMPUTE_UNUSED(idx);
+    ARM_COMPUTE_ERROR_ON(idx >= _outputs.size());
+
+    const Tensor *src = input(0);
+    ARM_COMPUTE_ERROR_ON(src == nullptr);
+
+    TensorDescriptor  output_desc = src->desc();
+    const TensorShape input_shape = src->desc().shape;
+    for(size_t dim = 0; dim < _padding.size(); ++dim)
+    {
+        output_desc.shape.set(dim, _padding[dim].first + input_shape[dim] + _padding[dim].second);
+    }
+
+    return output_desc;
+}
+
+NodeType PadLayerNode::type() const
+{
+    return NodeType::PadLayer;
+}
+
+void PadLayerNode::accept(INodeVisitor &v)
+{
+    v.visit(*this);
+}
+} // namespace graph
+} // namespace arm_compute