COMPMID-583 - Implemented reference implementation and validation tests (NEON and CL) for Histogram

Change-Id: Iccf6b4483cb8394dab2f861a737583126f9bed81
Reviewed-on: http://mpd-gerrit.cambridge.arm.com/91601
Tested-by: Kaizen <jeremy.johnson+kaizengerrit@arm.com>
Reviewed-by: Georgios Pinitas <georgios.pinitas@arm.com>
diff --git a/tests/validation/fixtures/HistogramFixture.h b/tests/validation/fixtures/HistogramFixture.h
new file mode 100644
index 0000000..943b2cd
--- /dev/null
+++ b/tests/validation/fixtures/HistogramFixture.h
@@ -0,0 +1,129 @@
+/*
+ * Copyright (c) 2017 ARM Limited.
+ *
+ * SPDX-License-Identifier: MIT
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+#ifndef ARM_COMPUTE_TEST_HISTOGRAM_FIXTURE
+#define ARM_COMPUTE_TEST_HISTOGRAM_FIXTURE
+
+#include "arm_compute/core/TensorShape.h"
+#include "arm_compute/core/Types.h"
+#include "tests/AssetsLibrary.h"
+#include "tests/Globals.h"
+#include "tests/IAccessor.h"
+#include "tests/framework/Asserts.h"
+#include "tests/framework/Fixture.h"
+#include "tests/validation/CPP/Histogram.h"
+#include "utils/Utils.h"
+
+#include <random>
+
+namespace arm_compute
+{
+namespace test
+{
+namespace validation
+{
+template <typename TensorType, typename AccessorType, typename FunctionType, typename T, typename DistributionType>
+class HistogramValidationFixture : public framework::Fixture
+{
+public:
+    template <typename...>
+    void setup(TensorShape shape, DataType data_type)
+    {
+        std::mt19937                            gen(library->seed());
+        std::uniform_int_distribution<size_t>   distribution_size_t(1, 30);
+        const size_t                            num_bins = distribution_size_t(gen);
+        std::uniform_int_distribution<int32_t>  distribution_int32_t(0, 125);
+        const size_t                            offset = distribution_int32_t(gen);
+        std::uniform_int_distribution<uint32_t> distribution_uint32_t(1, 255 - offset);
+        const size_t                            range = distribution_uint32_t(gen);
+
+        _target    = compute_target(shape, data_type, num_bins, offset, range);
+        _reference = compute_reference(shape, data_type, num_bins, offset, range);
+    }
+
+protected:
+    template <typename U>
+    void fill(U &&tensor)
+    {
+        library->fill_tensor_uniform(tensor, 0);
+    }
+
+    TensorType compute_target(const TensorShape &shape, DataType data_type, size_t num_bins, int32_t offset, uint32_t range)
+    {
+        // Create tensors
+        TensorType       src = create_tensor<TensorType>(shape, data_type);
+        TensorType       dst = create_tensor<TensorType>(TensorShape(num_bins), DataType::U32);
+        DistributionType distribution_dst(num_bins, offset, range);
+
+        // Create and configure function
+        FunctionType histogram;
+        histogram.configure(&src, &distribution_dst);
+        ARM_COMPUTE_EXPECT(src.info()->is_resizable(), framework::LogLevel::ERRORS);
+        ARM_COMPUTE_EXPECT(dst.info()->is_resizable(), framework::LogLevel::ERRORS);
+
+        // Allocate tensors
+        src.allocator()->allocate();
+        dst.allocator()->allocate();
+
+        ARM_COMPUTE_EXPECT(!src.info()->is_resizable(), framework::LogLevel::ERRORS);
+        ARM_COMPUTE_EXPECT(!dst.info()->is_resizable(), framework::LogLevel::ERRORS);
+
+        // Fill tensors
+        fill(AccessorType(src));
+
+        // Compute function
+        histogram.run();
+
+        // Copy the distribution in a tensor
+        arm_compute::utils::map(distribution_dst, true);
+        AccessorType accessor_dst = AccessorType(dst);
+        uint32_t    *dst_data     = static_cast<uint32_t *>(accessor_dst.data());
+
+        ARM_COMPUTE_EXPECT(accessor_dst.size() <= dst.info()->total_size(), framework::LogLevel::ERRORS);
+
+        std::copy_n(distribution_dst.buffer(), num_bins, dst_data);
+        arm_compute::utils::unmap(distribution_dst);
+        return dst;
+    }
+
+    SimpleTensor<uint32_t> compute_reference(const TensorShape &shape, DataType data_type, size_t num_bins, int32_t offset, uint32_t range)
+    {
+        ARM_COMPUTE_ERROR_ON(data_type != DataType::U8);
+
+        // Create reference
+        SimpleTensor<T> src{ shape, data_type };
+
+        // Fill reference
+        fill(src);
+
+        // Compute reference
+        return reference::histogram<T>(src, num_bins, offset, range);
+    }
+
+    TensorType             _target{};
+    SimpleTensor<uint32_t> _reference{};
+};
+} // namespace validation
+} // namespace test
+} // namespace arm_compute
+#endif /* ARM_COMPUTE_TEST_HISTOGRAM_FIXTURE */