IVGCVSW-3975 Add reference workload for LOG_SOFTMAX

Signed-off-by: Aron Virginas-Tar <Aron.Virginas-Tar@arm.com>
Change-Id: I10bb7133e0e2d6d7199abdf39562b1226bbbd3e7

6 files changed, 173 insertions, 0 deletions

diff --git a/src/backends/reference/workloads/CMakeLists.txt b/src/backends/reference/workloads/CMakeLists.txt
index 9a5f427d37..b8eb95c729 100644
--- a/src/backends/reference/workloads/CMakeLists.txt
+++ b/src/backends/reference/workloads/CMakeLists.txt
@@ -37,6 +37,8 @@ list(APPEND armnnRefBackendWorkloads_sources
     Gather.hpp
     InstanceNorm.cpp
     InstanceNorm.hpp
+    LogSoftmax.cpp
+    LogSoftmax.hpp
     LstmUtils.hpp
     LstmUtils.cpp
     Maximum.hpp
@@ -95,6 +97,8 @@ list(APPEND armnnRefBackendWorkloads_sources
     RefInstanceNormalizationWorkload.hpp
     RefL2NormalizationWorkload.cpp
     RefL2NormalizationWorkload.hpp
+    RefLogSoftmaxWorkload.cpp
+    RefLogSoftmaxWorkload.hpp
     RefLstmWorkload.cpp
     RefLstmWorkload.hpp
     RefMeanWorkload.cpp
diff --git a/src/backends/reference/workloads/LogSoftmax.cpp b/src/backends/reference/workloads/LogSoftmax.cpp
new file mode 100644
index 0000000000..3fa3dc0d8c
--- /dev/null
+++ b/src/backends/reference/workloads/LogSoftmax.cpp
@@ -0,0 +1,91 @@
+//
+// Copyright © 2019 Arm Ltd. All rights reserved.
+// SPDX-License-Identifier: MIT
+//
+
+#include "LogSoftmax.hpp"
+
+#include <TensorUtils.hpp>
+
+#include <cmath>
+
+#include <boost/assert.hpp>
+#include <boost/core/ignore_unused.hpp>
+#include <boost/numeric/conversion/cast.hpp>
+
+namespace
+{
+
+inline bool ValidateAxis(int axis, unsigned int numDimensions)
+{
+    const int sNumDimensions = boost::numeric_cast<int>(numDimensions);
+    return axis < sNumDimensions && axis >= -sNumDimensions;
+}
+
+} // anonymous namespace
+
+namespace armnn
+{
+
+void LogSoftmax(Decoder<float>& input,
+                Encoder<float>& output,
+                const TensorInfo& inputInfo,
+                const LogSoftmaxDescriptor& descriptor)
+{
+    const unsigned int numDimensions = inputInfo.GetNumDimensions();
+
+    bool axisIsValid = ValidateAxis(descriptor.m_Axis, numDimensions);
+    BOOST_ASSERT_MSG(axisIsValid,
+        "Axis index is not in range [-numDimensions, numDimensions).");
+    boost::ignore_unused(axisIsValid);
+
+    unsigned int uAxis = descriptor.m_Axis < 0  ?
+        numDimensions - boost::numeric_cast<unsigned int>(std::abs(descriptor.m_Axis)) :
+        boost::numeric_cast<unsigned int>(descriptor.m_Axis);
+
+    const TensorShape& inputShape = inputInfo.GetShape();
+    const unsigned int outerSize  = armnnUtils::GetNumElementsBetween(inputShape, 0, uAxis);
+    const unsigned int axisSize   = inputShape[uAxis];
+    const unsigned int innerSize  = armnnUtils::GetNumElementsBetween(inputShape,
+                                                                      uAxis + 1,
+                                                                      inputShape.GetNumDimensions());
+
+    for (unsigned int outer = 0; outer < outerSize; ++outer)
+    {
+        for (unsigned int inner = 0; inner < innerSize; ++inner)
+        {
+            // Find max
+            input[outer * axisSize * innerSize + inner];
+            float maxValue = input.Get();
+            for (unsigned int i = 1u; i < axisSize; ++i)
+            {
+                input[(outer * axisSize + i) * innerSize + inner];
+                maxValue = std::max(maxValue, input.Get());
+            }
+
+            // Compute sum
+            float sum = 0.0f;
+            for (unsigned int i = 0u; i < axisSize; ++i)
+            {
+                input[(outer * axisSize + i) * innerSize + inner];
+                sum += std::exp((input.Get() - maxValue) * descriptor.m_Beta);
+            }
+
+            // Compute log sum
+            const float logSum = std::log(sum);
+
+            // Compute result
+            for (unsigned int i = 0u; i < axisSize; ++i)
+            {
+                const unsigned int index = (outer * axisSize + i) * innerSize + inner;
+
+                input [index];
+                output[index];
+
+                output.Set((input.Get() - maxValue) * descriptor.m_Beta - logSum);
+            }
+        }
+    }
+}
+
+} // namespace armnn
diff --git a/src/backends/reference/workloads/LogSoftmax.hpp b/src/backends/reference/workloads/LogSoftmax.hpp
new file mode 100644
index 0000000000..2e383992c9
--- /dev/null
+++ b/src/backends/reference/workloads/LogSoftmax.hpp
@@ -0,0 +1,20 @@
+//
+// Copyright © 2019 Arm Ltd. All rights reserved.
+// SPDX-License-Identifier: MIT
+//
+
+#pragma once
+
+#include "BaseIterator.hpp"
+
+#include <armnn/Tensor.hpp>
+
+namespace armnn
+{
+
+void LogSoftmax(Decoder<float>& input,
+                Encoder<float>& output,
+                const TensorInfo& inputInfo,
+                const LogSoftmaxDescriptor& descriptor);
+
+} // namespace armnn
diff --git a/src/backends/reference/workloads/RefLogSoftmaxWorkload.cpp b/src/backends/reference/workloads/RefLogSoftmaxWorkload.cpp
new file mode 100644
index 0000000000..a987e79dda
--- /dev/null
+++ b/src/backends/reference/workloads/RefLogSoftmaxWorkload.cpp
@@ -0,0 +1,36 @@
+//
+// Copyright © 2019 Arm Ltd. All rights reserved.
+// SPDX-License-Identifier: MIT
+//
+
+#include "RefLogSoftmaxWorkload.hpp"
+
+#include "Decoders.hpp"
+#include "Encoders.hpp"
+#include "LogSoftmax.hpp"
+#include "RefWorkloadUtils.hpp"
+
+#include <Profiling.hpp>
+
+#include <boost/assert.hpp>
+
+namespace armnn
+{
+
+void RefLogSoftmaxWorkload::Execute() const
+{
+    ARMNN_SCOPED_PROFILING_EVENT(Compute::CpuRef, "RefLogSoftmaxWorkload_Execute");
+
+    const TensorInfo& inputInfo  = GetTensorInfo(m_Data.m_Inputs[0]);
+    const TensorInfo& outputInfo = GetTensorInfo(m_Data.m_Outputs[0]);
+
+    std::unique_ptr<Decoder<float>> decoder = MakeDecoder<float>(inputInfo, m_Data.m_Inputs[0]->Map());
+    std::unique_ptr<Encoder<float>> encoder = MakeEncoder<float>(outputInfo, m_Data.m_Outputs[0]->Map());
+
+    BOOST_ASSERT(decoder != nullptr);
+    BOOST_ASSERT(encoder != nullptr);
+
+    LogSoftmax(*decoder, *encoder, inputInfo, m_Data.m_Parameters);
+}
+
+} // namespace armnn
diff --git a/src/backends/reference/workloads/RefLogSoftmaxWorkload.hpp b/src/backends/reference/workloads/RefLogSoftmaxWorkload.hpp
new file mode 100644
index 0000000000..f5048d90b3
--- /dev/null
+++ b/src/backends/reference/workloads/RefLogSoftmaxWorkload.hpp
@@ -0,0 +1,21 @@
+//
+// Copyright © 2019 Arm Ltd. All rights reserved.
+// SPDX-License-Identifier: MIT
+//
+
+#pragma once
+
+#include <backendsCommon/Workload.hpp>
+#include <backendsCommon/WorkloadData.hpp>
+
+namespace armnn
+{
+
+class RefLogSoftmaxWorkload : public BaseWorkload<LogSoftmaxQueueDescriptor>
+{
+public:
+    using BaseWorkload<LogSoftmaxQueueDescriptor>::BaseWorkload;
+    virtual void Execute() const override;
+};
+
+} // namespace armnn
diff --git a/src/backends/reference/workloads/RefWorkloads.hpp b/src/backends/reference/workloads/RefWorkloads.hpp
index 39dfa0517b..79d1935823 100644
--- a/src/backends/reference/workloads/RefWorkloads.hpp
+++ b/src/backends/reference/workloads/RefWorkloads.hpp
@@ -38,6 +38,7 @@
 #include "RefGatherWorkload.hpp"
 #include "RefInstanceNormalizationWorkload.hpp"
 #include "RefL2NormalizationWorkload.hpp"
+#include "RefLogSoftmaxWorkload.hpp"
 #include "RefLstmWorkload.hpp"
 #include "RefMeanWorkload.hpp"
 #include "RefNormalizationWorkload.hpp"