IVGCVSW-5410 Add front-end support for CAST

IVGCVSW-5415 Add TfLiteParser support for CAST

 * Added front end support for CAST, including support in the
Reference workload, Serialization, Deserializtion, Unit tests, and
TfLiteParser.

Signed-off-by: mathad01 <matthew.haddon@arm.com>
Change-Id: Iaf670ca5912a21ed6bc84f7f83a68b42154846bb

3 files changed, 114 insertions, 0 deletions

diff --git a/src/armnnTfLiteParser/TfLiteParser.cpp b/src/armnnTfLiteParser/TfLiteParser.cpp
index cb3426ea5b..5f8b08bf85 100644
--- a/src/armnnTfLiteParser/TfLiteParser.cpp
+++ b/src/armnnTfLiteParser/TfLiteParser.cpp
@@ -608,6 +608,7 @@ TfLiteParserImpl::TfLiteParserImpl(const Optional<ITfLiteParser::TfLiteParserOpt
     m_ParserFunctions[tflite::BuiltinOperator_ARG_MAX]                 = &TfLiteParserImpl::ParseArgMax;
     m_ParserFunctions[tflite::BuiltinOperator_AVERAGE_POOL_2D]         = &TfLiteParserImpl::ParseAveragePool2D;
     m_ParserFunctions[tflite::BuiltinOperator_BATCH_TO_SPACE_ND]       = &TfLiteParserImpl::ParseBatchToSpaceND;
+    m_ParserFunctions[tflite::BuiltinOperator_CAST]                    = &TfLiteParserImpl::ParseCast;
     m_ParserFunctions[tflite::BuiltinOperator_CONCATENATION]           = &TfLiteParserImpl::ParseConcatenation;
     m_ParserFunctions[tflite::BuiltinOperator_CONV_2D]                 = &TfLiteParserImpl::ParseConv2D;
     m_ParserFunctions[tflite::BuiltinOperator_CUSTOM]                  = &TfLiteParserImpl::ParseCustomOperator;
@@ -876,6 +877,30 @@ void TfLiteParserImpl::ParseUnsupportedOperator(size_t subgraphIndex, size_t ope
     RegisterOutputSlots(subgraphIndex, operatorIndex, layer, outputTensorIds);
 }
 
+void TfLiteParserImpl::ParseCast(size_t subgraphIndex, size_t operatorIndex)
+{
+    CHECK_MODEL(m_Model, subgraphIndex, operatorIndex);
+
+    auto inputs = GetInputs(m_Model, subgraphIndex, operatorIndex);
+    CHECK_VALID_SIZE(inputs.size(), 1);
+    auto outputs = GetOutputs(m_Model, subgraphIndex, operatorIndex);
+    CHECK_VALID_SIZE(outputs.size(), 1);
+
+    auto layerName = fmt::format("Cast:{}:{}", subgraphIndex, operatorIndex);
+
+    IConnectableLayer* layer = m_Network->AddCastLayer(layerName.c_str());
+    ARMNN_ASSERT(layer != nullptr);
+
+    TensorInfo outputTensorInfo = ToTensorInfo(outputs[0], true);
+    layer->GetOutputSlot(0).SetTensorInfo(outputTensorInfo);
+
+    auto inputTensorIndexes = AsUnsignedVector(GetInputTensorIds(m_Model, subgraphIndex, operatorIndex));
+    RegisterInputSlots(subgraphIndex, operatorIndex, layer, {inputTensorIndexes[0]});
+
+    auto outputTensorIndexes = AsUnsignedVector(GetOutputTensorIds(m_Model, subgraphIndex, operatorIndex));
+    RegisterOutputSlots(subgraphIndex, operatorIndex, layer, outputTensorIndexes);
+}
+
 void TfLiteParserImpl::ParseConv2D(size_t subgraphIndex, size_t operatorIndex)
 {
     CHECK_MODEL(m_Model, subgraphIndex, operatorIndex);
diff --git a/src/armnnTfLiteParser/TfLiteParser.hpp b/src/armnnTfLiteParser/TfLiteParser.hpp
index 90517f5aad..af844d2ef3 100644
--- a/src/armnnTfLiteParser/TfLiteParser.hpp
+++ b/src/armnnTfLiteParser/TfLiteParser.hpp
@@ -104,6 +104,7 @@ private:
     void ParseArgMax(size_t subgraphIndex, size_t operatorIndex);
     void ParseAveragePool2D(size_t subgraphIndex, size_t operatorIndex);
     void ParseBatchToSpaceND(size_t subgraphIndex, size_t operatorIndex);
+    void ParseCast(size_t subgraphIndex, size_t operatorIndex);
     void ParseConcatenation(size_t subgraphIndex, size_t operatorIndex);
     void ParseConv2D(size_t subgraphIndex, size_t operatorIndex);
     void ParseDepthToSpace(size_t subgraphIndex, size_t operatorIndex);
diff --git a/src/armnnTfLiteParser/test/Cast.cpp b/src/armnnTfLiteParser/test/Cast.cpp
new file mode 100644
index 0000000000..e0f9c63e72
--- /dev/null
+++ b/src/armnnTfLiteParser/test/Cast.cpp
@@ -0,0 +1,88 @@
+//
+// Copyright © 2021 Arm Ltd and Contributors. All rights reserved.
+// SPDX-License-Identifier: MIT
+//
+
+#include <boost/test/unit_test.hpp>
+#include "ParserFlatbuffersFixture.hpp"
+#include "../TfLiteParser.hpp"
+
+#include <string>
+#include <iostream>
+
+BOOST_AUTO_TEST_SUITE(TensorflowLiteParser)
+
+struct CastFixture : public ParserFlatbuffersFixture
+{
+    explicit CastFixture(const std::string& inputShape,
+                         const std::string& outputShape,
+                         const std::string& inputDataType,
+                         const std::string& outputDataType)
+    {
+        m_JsonString = R"(
+            {
+                "version": 3,
+                "operator_codes": [ { "builtin_code": "CAST" } ],
+                "subgraphs": [ {
+                    "tensors": [
+                        {
+                            "shape": )" + inputShape + R"(,
+                            "type": )" + inputDataType + R"(,
+                            "buffer": 0,
+                            "name": "inputTensor",
+                            "quantization": {
+                                "min": [ 0.0 ],
+                                "max": [ 255.0 ],
+                                "scale": [ 1.0 ],
+                                "zero_point": [ 0 ],
+                            }
+                        },
+                        {
+                            "shape": )" + outputShape + R"(,
+                            "type": )" + outputDataType + R"(,
+                            "buffer": 1,
+                            "name": "outputTensor",
+                            "quantization": {
+                                "min": [ 0.0 ],
+                                "max": [ 255.0 ],
+                                "scale": [ 1.0 ],
+                                "zero_point": [ 0 ],
+                            }
+                        }
+                    ],
+                    "inputs": [ 0 ],
+                    "outputs": [ 1 ],
+                    "operators": [
+                        {
+                          "opcode_index": 0,
+                          "inputs": [ 0 ],
+                          "outputs": [ 1 ],
+                          "custom_options_format": "FLEXBUFFERS"
+                        }
+                    ],
+                } ],
+                "buffers" : [ {}, {} ]
+            }
+        )";
+        SetupSingleInputSingleOutput("inputTensor", "outputTensor");
+    }
+};
+
+struct SimpleCastFixture : CastFixture
+{
+    SimpleCastFixture() : CastFixture("[ 1, 6 ]",
+                                      "[ 1, 6 ]",
+                                      "INT32",
+                                      "FLOAT32") {}
+};
+
+BOOST_FIXTURE_TEST_CASE(SimpleCast, SimpleCastFixture)
+{
+RunTest<2, armnn::DataType::Signed32 , armnn::DataType::Float32>(
+0,
+{{"inputTensor",  { 0,   -1,   5,   -100,   200,   -255 }}},
+{{"outputTensor", { 0.0f, -1.0f, 5.0f, -100.0f, 200.0f, -255.0f }}});
+}
+
+
+BOOST_AUTO_TEST_SUITE_END()
\ No newline at end of file