COMPMID-415: Cleanup accessors

Change-Id: Id19c8c1ea76f6e6679a4ac770e804f8012a2b5a6
Reviewed-on: http://mpd-gerrit.cambridge.arm.com/80937
Tested-by: Kaizen <jeremy.johnson+kaizengerrit@arm.com>
Reviewed-by: Anthony Barbier <anthony.barbier@arm.com>
diff --git a/tests/NEON/LutAccessor.h b/tests/NEON/LutAccessor.h
new file mode 100644
index 0000000..24ad63d
--- /dev/null
+++ b/tests/NEON/LutAccessor.h
@@ -0,0 +1,86 @@
+/*
+ * 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_NEON_LUTACCESSOR_H__
+#define __ARM_COMPUTE_TEST_NEON_LUTACCESSOR_H__
+
+#include "ILutAccessor.h"
+
+#include "arm_compute/runtime/Lut.h"
+
+namespace arm_compute
+{
+namespace test
+{
+/** Accessor implementation for @ref Lut objects. */
+template <typename T>
+class LutAccessor : public ILutAccessor<T>
+{
+public:
+    /** Create an accessor for the given @p Lut.
+     */
+    LutAccessor(Lut &lut)
+        : _lut{ lut }
+    {
+    }
+
+    LutAccessor(const LutAccessor &) = delete;
+    LutAccessor &operator=(const LutAccessor &) = delete;
+    LutAccessor(LutAccessor &&)                 = default;
+    LutAccessor &operator=(LutAccessor &&) = default;
+
+    int num_elements() const override
+    {
+        return _lut.num_elements();
+    }
+
+    const T &operator[](T input_value) const override
+    {
+        auto    lut        = reinterpret_cast<T *>(_lut.buffer());
+        int32_t real_index = _lut.index_offset() + static_cast<int32_t>(input_value);
+
+        if(0 <= real_index && real_index < num_elements())
+        {
+            return lut[real_index];
+        }
+        ARM_COMPUTE_ERROR("Error index not in range.");
+    }
+
+    T &operator[](T input_value) override
+    {
+        auto    lut        = reinterpret_cast<T *>(_lut.buffer());
+        int32_t real_index = _lut.index_offset() + static_cast<int32_t>(input_value);
+
+        if(0 <= real_index && real_index < num_elements())
+        {
+            return lut[real_index];
+        }
+        ARM_COMPUTE_ERROR("Error index not in range.");
+    }
+
+private:
+    ILut &_lut;
+};
+} // namespace test
+} // namespace arm_compute
+#endif /* __ARM_COMPUTE_TEST_NEON_LUTACCESSOR_H__ */