COMPMID-2076: Add StackLayer to the graph API

Change-Id: Ifae23659c2471d9c052bc8adf066c5228d6e8b23
Signed-off-by: Michele Di Giorgio <michele.digiorgio@arm.com>
Reviewed-on: https://review.mlplatform.org/c/893
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Georgios Pinitas <georgios.pinitas@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>

4 files changed, 144 insertions, 14 deletions

diff --git a/src/graph/GraphBuilder.cpp b/src/graph/GraphBuilder.cpp
index 74f60d5354..3f40aeadcb 100644
--- a/src/graph/GraphBuilder.cpp
+++ b/src/graph/GraphBuilder.cpp
@@ -81,6 +81,24 @@ NodeID create_simple_single_input_output_node(Graph &g, NodeParams &params, Node
 
     return nid;
 }
+
+template <typename NT, typename... Args>
+NodeID create_simple_multiple_input_single_output_node(Graph &g, NodeParams &params, std::vector<NodeIdxPair> inputs, Args &&... args)
+{
+    ARM_COMPUTE_ERROR_ON(inputs.size() == 0);
+
+    NodeID nid = g.add_node<NT>(std::forward<Args>(args)...);
+
+    unsigned int i = 0;
+    for(const auto &input : inputs)
+    {
+        CHECK_NODEIDX_PAIR(input, g);
+        g.add_connection(input.node_id, input.index, nid, i++);
+    }
+    set_node_params(g, nid, params);
+
+    return nid;
+}
 } // namespace
 
 NodeID GraphBuilder::add_const_node(Graph &g, NodeParams params, TensorDescriptor desc, ITensorAccessorUPtr accessor)
@@ -294,21 +312,9 @@ NodeID GraphBuilder::add_deconvolution_node(Graph &g, NodeParams params, NodeIdx
     return deconv_nid;
 }
 
-NodeID GraphBuilder::add_concatenate_node(Graph &g, NodeParams params, std::vector<NodeIdxPair> inputs, descriptors::ConcatLayerDescriptor concat_descriptor)
+NodeID GraphBuilder::add_concatenate_node(Graph &g, NodeParams params, const std::vector<NodeIdxPair> &inputs, descriptors::ConcatLayerDescriptor concat_descriptor)
 {
-    ARM_COMPUTE_ERROR_ON(inputs.size() == 0);
-
-    NodeID nid = g.add_node<ConcatenateLayerNode>(inputs.size(), concat_descriptor);
-
-    unsigned int i = 0;
-    for(const auto &input : inputs)
-    {
-        CHECK_NODEIDX_PAIR(input, g);
-        g.add_connection(input.node_id, input.index, nid, i++);
-    }
-    set_node_params(g, nid, params);
-
-    return nid;
+    return create_simple_multiple_input_single_output_node<ConcatenateLayerNode>(g, params, inputs, inputs.size(), concat_descriptor);
 }
 
 NodeID GraphBuilder::add_depthwise_convolution_node(Graph &g, NodeParams params, NodeIdxPair input, Size2D kernel_spatial_extend,
@@ -627,6 +633,11 @@ NodeID GraphBuilder::add_split_node(Graph &g, NodeParams params, NodeIdxPair inp
     return create_simple_single_input_output_node<SplitLayerNode>(g, params, input, num_splits, axis);
 }
 
+NodeID GraphBuilder::add_stack_node(Graph &g, NodeParams params, const std::vector<NodeIdxPair> &inputs, int axis)
+{
+    return create_simple_multiple_input_single_output_node<StackLayerNode>(g, params, inputs, inputs.size(), axis);
+}
+
 NodeID GraphBuilder::add_upsample_node(Graph &g, NodeParams params, NodeIdxPair input, Size2D info, InterpolationPolicy upsampling_policy)
 {
     return create_simple_single_input_output_node<UpsampleLayerNode>(g, params, input, info, upsampling_policy);
diff --git a/src/graph/backends/CL/CLFunctionsFactory.cpp b/src/graph/backends/CL/CLFunctionsFactory.cpp
index 7473ff480f..90c1613604 100644
--- a/src/graph/backends/CL/CLFunctionsFactory.cpp
+++ b/src/graph/backends/CL/CLFunctionsFactory.cpp
@@ -229,6 +229,8 @@ std::unique_ptr<IFunction> CLFunctionFactory::create(INode *node, GraphContext &
             return detail::create_slice_layer<CLSlice, CLTargetInfo>(*polymorphic_downcast<SliceLayerNode *>(node));
         case NodeType::SoftmaxLayer:
             return detail::create_softmax_layer<CLSoftmaxLayer, CLTargetInfo>(*polymorphic_downcast<SoftmaxLayerNode *>(node), ctx);
+        case NodeType::StackLayer:
+            return detail::create_stack_layer<CLStackLayer, CLTargetInfo>(*polymorphic_downcast<StackLayerNode *>(node));
         case NodeType::UpsampleLayer:
             return detail::create_upsample_layer<CLUpsampleLayer, CLTargetInfo>(*polymorphic_downcast<UpsampleLayerNode *>(node), ctx);
         case NodeType::YOLOLayer:
diff --git a/src/graph/backends/NEON/NEFunctionFactory.cpp b/src/graph/backends/NEON/NEFunctionFactory.cpp
index 81c6e09f92..690a311408 100644
--- a/src/graph/backends/NEON/NEFunctionFactory.cpp
+++ b/src/graph/backends/NEON/NEFunctionFactory.cpp
@@ -238,6 +238,8 @@ std::unique_ptr<IFunction> NEFunctionFactory::create(INode *node, GraphContext &
             return detail::create_resize_layer<NEScale, NETargetInfo>(*polymorphic_downcast<ResizeLayerNode *>(node));
         case NodeType::SoftmaxLayer:
             return detail::create_softmax_layer<NESoftmaxLayer, NETargetInfo>(*polymorphic_downcast<SoftmaxLayerNode *>(node), ctx);
+        case NodeType::StackLayer:
+            return detail::create_stack_layer<NEStackLayer, NETargetInfo>(*polymorphic_downcast<StackLayerNode *>(node));
         case NodeType::UpsampleLayer:
             return detail::create_upsample_layer<NEUpsampleLayer, NETargetInfo>(*polymorphic_downcast<UpsampleLayerNode *>(node), ctx);
         case NodeType::YOLOLayer:
diff --git a/src/graph/nodes/StackLayerNode.cpp b/src/graph/nodes/StackLayerNode.cpp
new file mode 100644
index 0000000000..d26498ad77
--- /dev/null
+++ b/src/graph/nodes/StackLayerNode.cpp
@@ -0,0 +1,115 @@
+/*
+ * Copyright (c) 2019 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/StackLayerNode.h"
+
+#include "arm_compute/core/TensorInfo.h"
+#include "arm_compute/core/Utils.h"
+#include "arm_compute/graph/Graph.h"
+#include "arm_compute/graph/INodeVisitor.h"
+#include "arm_compute/graph/Utils.h"
+
+#include "arm_compute/core/utils/misc/ShapeCalculator.h"
+
+namespace arm_compute
+{
+namespace graph
+{
+StackLayerNode::StackLayerNode(unsigned int total_nodes, int axis)
+    : _total_nodes(total_nodes), _axis(axis)
+{
+    _input_edges.resize(_total_nodes, EmptyEdgeID);
+    _outputs.resize(1, NullTensorID);
+}
+
+int StackLayerNode::axis() const
+{
+    return _axis;
+}
+
+TensorDescriptor StackLayerNode::compute_output_descriptor(const std::vector<TensorDescriptor> &input_descriptors,
+                                                           int                                  axis)
+{
+    ARM_COMPUTE_ERROR_ON(input_descriptors.size() == 0);
+
+    TensorDescriptor output_descriptor = input_descriptors[0];
+
+    const TensorInfo   input_info(input_descriptors[0].shape, 1, input_descriptors[0].data_type);
+    const unsigned int num_tensors = input_descriptors.size();
+
+    output_descriptor.shape = arm_compute::misc::shape_calculator::compute_stack_shape(input_info, axis, num_tensors);
+
+    return output_descriptor;
+}
+
+bool StackLayerNode::forward_descriptors()
+{
+    if(_outputs[0] != NullTensorID)
+    {
+        Tensor *dst = output(0);
+        ARM_COMPUTE_ERROR_ON(dst == nullptr);
+        dst->desc() = configure_output(0);
+        return true;
+    }
+    return false;
+}
+
+TensorDescriptor StackLayerNode::configure_output(size_t idx) const
+{
+    ARM_COMPUTE_UNUSED(idx);
+    ARM_COMPUTE_ERROR_ON(idx >= _outputs.size());
+
+    // Check if all input tensors are set
+    bool are_all_inputs_set = std::all_of(std::begin(_input_edges), std::end(_input_edges), [](const EdgeID & eid)
+    {
+        return eid != EmptyEdgeID;
+    });
+
+    TensorDescriptor output_info = {};
+
+    if(are_all_inputs_set)
+    {
+        std::vector<TensorDescriptor> inputs_descriptors;
+        for(unsigned int i = 0; i < _input_edges.size(); ++i)
+        {
+            const Tensor *t = _graph->tensor(input_id(i));
+            ARM_COMPUTE_ERROR_ON(t == nullptr);
+            inputs_descriptors.push_back(t->desc());
+        }
+        output_info = compute_output_descriptor(inputs_descriptors, _axis);
+    }
+
+    return output_info;
+}
+
+NodeType StackLayerNode::type() const
+{
+    return NodeType::StackLayer;
+}
+
+void StackLayerNode::accept(INodeVisitor &v)
+{
+    v.visit(*this);
+}
+} // namespace graph
+} // namespace arm_compute