IVGCVSW-2333 Add ParseSub method to TfParser

* Also added unit test Sub.cpp

Change-Id: I6d23c11ae894ee433cd28ffdf0248b14e01b0131
diff --git a/src/armnnTfParser/TfParser.cpp b/src/armnnTfParser/TfParser.cpp
index 0d42525..8f6352c 100644
--- a/src/armnnTfParser/TfParser.cpp
+++ b/src/armnnTfParser/TfParser.cpp
@@ -385,6 +385,7 @@
     { "Maximum",               &TfParser::ParseMaximum },
     { "Minimum",               &TfParser::ParseMinimum },
     { "Pad",                   &TfParser::ParsePad },
+    { "Sub",                   &TfParser::ParseSub },
 };
 
 ITfParser* ITfParser::CreateRaw()
@@ -1612,6 +1613,45 @@
     return std::make_unique<SingleLayerParsedTfOperation>(this, nodeDef, layer);
 }
 
+ParsedTfOperationPtr TfParser::ParseSub(const tensorflow::NodeDef& nodeDef, const tensorflow::GraphDef& graphDef)
+{
+    std::vector<OutputOfParsedTfOperation> inputs = GetInputParsedTfOperationsChecked(nodeDef, 2);
+
+    IOutputSlot* input0Slot = &inputs[0].m_IndexedValue->ResolveArmnnOutputSlot(inputs[0].m_Index);
+    IOutputSlot* input1Slot = &inputs[1].m_IndexedValue->ResolveArmnnOutputSlot(inputs[1].m_Index);
+
+    const TensorInfo& input0Info = input0Slot->GetTensorInfo();
+    const TensorInfo& input1Info = input1Slot->GetTensorInfo();
+
+    if (input0Info.GetNumDimensions() == 1)
+    {
+        const bool isNHWC = true;
+        input0Slot = AddBroadcastReshapeLayer(input1Slot, input0Slot, isNHWC, *m_Network, nodeDef);
+    }
+
+    if (input1Info.GetNumDimensions() == 1)
+    {
+        const bool isNHWC = true;
+        input1Slot = AddBroadcastReshapeLayer(input0Slot, input1Slot, isNHWC, *m_Network, nodeDef);
+    }
+
+    IConnectableLayer* const layer = m_Network->AddSubtractionLayer(nodeDef.name().c_str());
+
+    input0Slot->Connect(layer->GetInputSlot(0));
+    input1Slot->Connect(layer->GetInputSlot(1));
+
+    if (input0Info.GetNumDimensions() == 1)
+    {
+        layer->GetOutputSlot(0).SetTensorInfo(input1Slot->GetTensorInfo());
+    }
+    else
+    {
+        layer->GetOutputSlot(0).SetTensorInfo(input0Slot->GetTensorInfo());
+    }
+
+    return std::make_unique<SingleLayerParsedTfOperation>(this, nodeDef, layer);
+}
+
 unsigned int CheckPaddingTensor(const ConstTensor& paddingTensor,
                                 const TensorInfo& inputTensorInfo,
                                 const std::string& nodeName)
diff --git a/src/armnnTfParser/TfParser.hpp b/src/armnnTfParser/TfParser.hpp
index da78f48..5ca867c 100644
--- a/src/armnnTfParser/TfParser.hpp
+++ b/src/armnnTfParser/TfParser.hpp
@@ -157,6 +157,7 @@
     ParsedTfOperationPtr ParseMaximum(const tensorflow::NodeDef& nodeDef, const tensorflow::GraphDef& graphDef);
     ParsedTfOperationPtr ParseMinimum(const tensorflow::NodeDef& nodeDef, const tensorflow::GraphDef& graphDef);
     ParsedTfOperationPtr ParsePad(const tensorflow::NodeDef& nodeDef, const tensorflow::GraphDef& graphDef);
+    ParsedTfOperationPtr ParseSub(const tensorflow::NodeDef& nodeDef, const tensorflow::GraphDef& graphDef);
     ParsedTfOperationPtr AddActivationLayer(const tensorflow::NodeDef& nodeDef, armnn::ActivationDescriptor& desc);
     ParsedTfOperationPtr AddAdditionLayer(const tensorflow::NodeDef& nodeDef, bool isBiasAdd = false);
     ParsedTfOperationPtr AddRealDivLayer(const tensorflow::NodeDef& nodeDef);
diff --git a/src/armnnTfParser/test/Sub.cpp b/src/armnnTfParser/test/Sub.cpp
new file mode 100644
index 0000000..2b3cbe6
--- /dev/null
+++ b/src/armnnTfParser/test/Sub.cpp
@@ -0,0 +1,135 @@
+//
+// Copyright © 2017 Arm Ltd. All rights reserved.
+// SPDX-License-Identifier: MIT
+//
+
+#include <boost/test/unit_test.hpp>
+#include "armnnTfParser/ITfParser.hpp"
+#include "ParserPrototxtFixture.hpp"
+
+BOOST_AUTO_TEST_SUITE(TensorflowParser)
+
+struct SubFixture : public armnnUtils::ParserPrototxtFixture<armnnTfParser::ITfParser>
+{
+    SubFixture(const armnn::TensorShape& inputShape0, const armnn::TensorShape& inputShape1)
+    {
+        m_Prototext = R"(
+node {
+  name: "input0"
+  op: "Placeholder"
+  attr {
+    key: "dtype"
+    value {
+      type: DT_FLOAT
+    }
+  }
+  attr {
+    key: "shape"
+    value {
+      shape {
+      }
+    }
+  }
+}
+node {
+  name: "input1"
+  op: "Placeholder"
+  attr {
+    key: "dtype"
+    value {
+      type: DT_FLOAT
+    }
+  }
+  attr {
+    key: "shape"
+    value {
+      shape {
+      }
+    }
+  }
+}
+node {
+  name: "output"
+  op: "Sub"
+  input: "input0"
+  input: "input1"
+  attr {
+    key: "T"
+    value {
+      type: DT_FLOAT
+    }
+  }
+}
+        )";
+        Setup({ { "input0", inputShape0 },
+                { "input1", inputShape1 } },
+                { "output" });
+
+    }
+};
+
+struct SubFixture4D4D : public SubFixture
+{
+    SubFixture4D4D() : SubFixture({ 1, 2, 2, 3 }, { 1, 2, 2, 3 }) {}
+};
+
+BOOST_FIXTURE_TEST_CASE(ParseSub, SubFixture4D4D)
+{
+    RunTest<4>({ { "input0", { 5.0f,   1.0f,  2.0f,
+                               3.0f,   4.0f,  5.0f,
+                               6.0f,   7.0f,  8.0f,
+                               29.0f, 10.0f, 11.0f } },
+
+                 { "input1", { 0.0f,   1.0f,  3.0f,
+                               4.0f,   5.5f,  1.0f,
+                               2.0f,  17.0f, 18.0f,
+                               19.0f,  1.0f,  3.0f } } },
+
+               { { "output", {  5.0f,    0.0f,  -1.0f,
+                               -1.0f,   -1.5f,   4.0f,
+                                4.0f,  -10.0f, -10.0f,
+                               10.0f,    9.0f,   8.0f } } });
+}
+
+struct SubBroadcastFixture4D1D : public SubFixture
+{
+    SubBroadcastFixture4D1D() : SubFixture({ 1, 2, 2, 3 }, { 1 }) {}
+};
+
+BOOST_FIXTURE_TEST_CASE(ParseSubBroadcast4D1D, SubBroadcastFixture4D1D)
+{
+    RunTest<4>({ { "input0", { 0.0f, 1.0f, 2.0f,
+                               3.0f, 4.0f, 5.0f,
+                               6.0f, 7.0f, 8.0f,
+                               9.0f, 10.0f, 11.0f } },
+
+                 { "input1", { 5.0f } } },
+
+                 { { "output", { -5.0f, -4.0f, -3.0f,
+                                 -2.0f, -1.0f,  0.0f,
+                                  1.0f,  2.0f,  3.0f,
+                                  4.0f,  5.0f,  6.0f } } });
+}
+
+struct SubBroadcastFixture1D4D : public SubFixture
+{
+    SubBroadcastFixture1D4D() : SubFixture({ 1 }, { 1, 2, 2, 3 }) {}
+};
+
+BOOST_FIXTURE_TEST_CASE(ParseSubBroadcast1D4D, SubBroadcastFixture1D4D)
+{
+    RunTest<4>({ { "input0", { 3.0f } },
+
+                 { "input1", { 0.0f, 1.0f, 2.0f,
+                               3.0f, 4.0f, 5.0f,
+                               6.0f, 7.0f, 8.0f,
+                               9.0f, 10.0f, 11.0f } } },
+
+                 { { "output", {  3.0f,  2.0f,  1.0f,
+                                  0.0f, -1.0f, -2.0f,
+                                 -3.0f, -4.0f, -5.0f,
+                                 -6.0f, -7.0f, -8.0f } } });
+}
+
+
+BOOST_AUTO_TEST_SUITE_END()
\ No newline at end of file