Add NEG support to TFLite parser

* Added unit tests
* Updated Documentation

Signed-off-by: Darshan Patel <darsh.jp@gmail.com>
Change-Id: Id22ffebe60732a93798f72801eb8a2a23cdd7ec0

4 files changed, 114 insertions, 0 deletions

diff --git a/src/armnnTfLiteParser/TensorFlowLiteSupport.md b/src/armnnTfLiteParser/TensorFlowLiteSupport.md
index ff80ffc13f..9718b22798 100644
--- a/src/armnnTfLiteParser/TensorFlowLiteSupport.md
+++ b/src/armnnTfLiteParser/TensorFlowLiteSupport.md
@@ -42,6 +42,8 @@ The Arm NN SDK TensorFlow Lite parser currently supports the following operators
 
 * MUL
 
+* NEG
+
 * PACK
 
 * PAD
diff --git a/src/armnnTfLiteParser/TfLiteParser.cpp b/src/armnnTfLiteParser/TfLiteParser.cpp
index f4f675ea98..08bd68d2ae 100644
--- a/src/armnnTfLiteParser/TfLiteParser.cpp
+++ b/src/armnnTfLiteParser/TfLiteParser.cpp
@@ -510,6 +510,7 @@ TfLiteParser::TfLiteParser(const Optional<ITfLiteParser::TfLiteParserOptions>& o
     m_ParserFunctions[tflite::BuiltinOperator_MEAN]                    = &TfLiteParser::ParseMean;
     m_ParserFunctions[tflite::BuiltinOperator_MINIMUM]                 = &TfLiteParser::ParseMinimum;
     m_ParserFunctions[tflite::BuiltinOperator_MUL]                     = &TfLiteParser::ParseMul;
+    m_ParserFunctions[tflite::BuiltinOperator_NEG]                     = &TfLiteParser::ParseNeg;
     m_ParserFunctions[tflite::BuiltinOperator_PACK]                    = &TfLiteParser::ParsePack;
     m_ParserFunctions[tflite::BuiltinOperator_PAD]                     = &TfLiteParser::ParsePad;
     m_ParserFunctions[tflite::BuiltinOperator_QUANTIZE]                = &TfLiteParser::ParseQuantize;
@@ -1819,6 +1820,31 @@ void TfLiteParser::ParseMean(size_t subgraphIndex, size_t operatorIndex)
     RegisterOutputSlots(subgraphIndex, operatorIndex, layer, {outputTensorIndexes[0]});
 }
 
+void TfLiteParser::ParseNeg(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 = boost::str(boost::format("Neg:%1%:%2%") % subgraphIndex % operatorIndex);
+  armnn::ElementwiseUnaryDescriptor descriptor(armnn::UnaryOperation::Neg);
+  IConnectableLayer* layer = m_Network->AddElementwiseUnaryLayer(descriptor, layerName.c_str());
+  ARMNN_ASSERT(layer != nullptr);
+
+  TensorInfo outputTensorInfo = ToTensorInfo(outputs[0]);
+  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 TfLiteParser::ParsePad(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 f0f75afabd..c252b0f73f 100644
--- a/src/armnnTfLiteParser/TfLiteParser.hpp
+++ b/src/armnnTfLiteParser/TfLiteParser.hpp
@@ -112,6 +112,7 @@ private:
     void ParseMean(size_t subgraphIndex, size_t operatorIndex);
     void ParseMinimum(size_t subgraphIndex, size_t operatorIndex);
     void ParseMul(size_t subgraphIndex, size_t operatorIndex);
+    void ParseNeg(size_t subgraphIndex, size_t operatorIndex);
     void ParsePack(size_t subgraphIndex, size_t operatorIndex);
     void ParsePad(size_t subgraphIndex, size_t operatorIndex);
     void ParsePool(size_t subgraphIndex, size_t operatorIndex, armnn::PoolingAlgorithm algorithm);
diff --git a/src/armnnTfLiteParser/test/Neg.cpp b/src/armnnTfLiteParser/test/Neg.cpp
new file mode 100644
index 0000000000..39e1f9e82c
--- /dev/null
+++ b/src/armnnTfLiteParser/test/Neg.cpp
@@ -0,0 +1,85 @@
+//
+// Copyright © 2020 Arm Ltd. All rights reserved.
+// SPDX-License-Identifier: MIT
+//
+
+#include <boost/test/unit_test.hpp>
+#include "ParserFlatbuffersFixture.hpp"
+#include "../TfLiteParser.hpp"
+
+#include <string>
+
+BOOST_AUTO_TEST_SUITE(TensorflowLiteParser)
+
+struct NegFixture : public ParserFlatbuffersFixture
+{
+    explicit NegFixture(const std::string & inputShape,
+                        const std::string & outputShape)
+    {
+        m_JsonString = R"(
+            {
+                "version": 3,
+                "operator_codes": [ { "builtin_code": "NEG" } ],
+                "subgraphs": [ {
+                    "tensors": [
+                        {
+                            "shape": )" + inputShape + R"(,
+                            "type": "FLOAT32",
+                            "buffer": 0,
+                            "name": "inputTensor",
+                            "quantization": {
+                                "min": [ 0.0 ],
+                                "max": [ 255.0 ],
+                                "scale": [ 1.0 ],
+                                "zero_point": [ 0 ],
+                            }
+                        },
+                        {
+                            "shape": )" + outputShape + R"( ,
+                            "type": "FLOAT32",
+                            "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" : [
+                    { },
+                    { }
+                ]
+            }
+        )";
+        Setup();
+    }
+};
+
+struct SimpleNegFixture : public NegFixture
+{
+    SimpleNegFixture() : NegFixture("[ 1, 2, 3, 1 ]", "[ 1, 2, 3, 1 ]") {}
+};
+
+BOOST_FIXTURE_TEST_CASE(ParseNeg, SimpleNegFixture)
+{
+    using armnn::DataType;
+    RunTest<4, DataType::Float32>(0, {{ "inputTensor", { 0.0f, 1.0f, -2.0f,
+                                                         20.0855185f, -54.5980834f, 5.0f} }},
+                                     {{ "outputTensor",{ 0.0f, -1.0f, 2.0f,
+                                                         -20.0855185f, 54.5980834f, -5.0f} }});
+}
+
+BOOST_AUTO_TEST_SUITE_END()