IVGCVSW-7170 Add Concat support to TOSA Reference Backend

* Change comment for the unique tensor names in all tosa common operators

Signed-off-by: Kevin May <kevin.may@arm.com>
Change-Id: I247b4b2365d5f0173218c5dfd11fba12d2399959
diff --git a/src/backends/tosaCommon/operatorMappings/ConcatOperator.cpp b/src/backends/tosaCommon/operatorMappings/ConcatOperator.cpp
new file mode 100644
index 0000000..8c651be
--- /dev/null
+++ b/src/backends/tosaCommon/operatorMappings/ConcatOperator.cpp
@@ -0,0 +1,81 @@
+//
+// Copyright © 2022 Arm Ltd and Contributors. All rights reserved.
+// SPDX-License-Identifier: MIT
+//
+
+#include "ConcatOperator.hpp"
+
+TosaSerializationBasicBlock* ConvertConcatToTosaOperator(const Layer* layer,
+                                                         const std::vector<const TensorInfo*>& inputs,
+                                                         const std::vector<const TensorInfo*>& outputs,
+                                                         const OriginsDescriptor* concatDescriptor)
+{
+    auto numInputs = inputs.size();
+    std::vector<std::string> inputNames;
+    inputNames.reserve(numInputs);
+    std::string outputName = std::string("output0_");
+    std::string blockName  = std::string("Op_CONCAT_block_") + GetUniqueTosaMappingID();
+
+    // Set input names for validation purposes only.
+    if (layer == nullptr)
+    {
+        for (uint32_t i = 0; i < numInputs; ++i)
+        {
+            inputNames.push_back("input"+ std::to_string(i) +"_");
+        }
+    }
+    // If a layer is present then the block will be used for execution, so input and output names need to be determined
+    // using the previous and following layers so the graph is connected correctly. For validation this doesn't matter.
+    else
+    {
+        // Get the layers connected to the input slots and determine unique tensor names.
+        for (uint32_t i = 0; i < numInputs; ++i)
+        {
+            Layer& connectedLayer = layer->GetInputSlot(i).GetConnectedOutputSlot()->GetOwningLayer();
+
+            std::string inputName = GenerateUniqueName(connectedLayer, i);
+            inputNames.push_back(inputName);
+        }
+
+        // Determine unique output tensor name.
+        outputName = GenerateUniqueOutputName(*layer, 0);
+    }
+
+    auto axis = static_cast<int32_t>(concatDescriptor->GetConcatAxis());
+    TosaAxisAttribute attribute(axis);
+
+    TosaSerializationOperator* op = new TosaSerializationOperator(Op_CONCAT,
+                                                                  Attribute_AxisAttribute,
+                                                                  &attribute,
+                                                                  inputNames,
+                                                                  {outputName});
+
+    std::vector<TosaSerializationTensor*> tensors;
+    tensors.reserve(numInputs);
+
+    for (uint32_t i = 0; i < numInputs; ++i)
+    {
+        // Only add input tensors for validation or when the connected layer is an input layer.
+        // As there can't be duplicate tensors and intermediate or constant tensors are created separately.
+        if(inputNames[i].find("input") != std::string::npos)
+        {
+            std::vector<int32_t> inputShape = GetTosaTensorShape(inputs[i]->GetShape());
+            DType inputDType = ArmNNToDType(inputs[i]->GetDataType());
+            tensors.push_back(new TosaSerializationTensor(inputNames[i], inputShape, inputDType, {}));
+        }
+    }
+
+    std::vector<int32_t> outputShape0 = GetTosaTensorShape(outputs[0]->GetShape());
+    DType outputDType0 = ArmNNToDType(outputs[0]->GetDataType());
+
+    TosaSerializationTensor* outputTensor0 = new TosaSerializationTensor(outputName, outputShape0, outputDType0, {});
+    tensors.push_back(outputTensor0);
+
+    // operatorInputNames/operatorOutputNames ends up being the same as
+    // blockInputNames/blockOutputNames for one-to-one ArmNN to TOSA mappings
+    return new TosaSerializationBasicBlock(blockName,     // name
+                                           {op},          // operators
+                                           tensors,       // tensors
+                                           inputNames,    // inputs
+                                           {outputName}); // outputs
+}
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