COMPMID-424 - Implemented reference implementation and tests (NEON and CL) for TableLookup

Change-Id: I53098ee750ab07fe64e9e2af8df91954d64017f5
Reviewed-on: http://mpd-gerrit.cambridge.arm.com/79411
Tested-by: Kaizen <jeremy.johnson+kaizengerrit@arm.com>
Reviewed-by: Steven Niu <steven.niu@arm.com>
diff --git a/tests/CL/CLLutAccessor.h b/tests/CL/CLLutAccessor.h
new file mode 100644
index 0000000..49bd12f
--- /dev/null
+++ b/tests/CL/CLLutAccessor.h
@@ -0,0 +1,95 @@
+/*
+ * 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_CL_CLLUTACCESSOR_H__
+#define __ARM_COMPUTE_TEST_CL_CLLUTACCESSOR_H__
+
+#include "ILutAccessor.h"
+
+#include "arm_compute/runtime/CL/CLLut.h"
+
+namespace arm_compute
+{
+namespace test
+{
+namespace cl
+{
+/** Accessor implementation for @ref CLLut objects. */
+template <typename T>
+class CLLutAccessor : public ILutAccessor<T>
+{
+public:
+    /** Create an accessor for the given @p CLLut.
+     */
+    CLLutAccessor(CLLut &lut)
+        : _lut{ lut }
+    {
+        _lut.map(true);
+    }
+    ~CLLutAccessor()
+    {
+        _lut.unmap();
+    }
+
+    CLLutAccessor(const CLLutAccessor &) = delete;
+    CLLutAccessor &operator=(const CLLutAccessor &) = delete;
+    CLLutAccessor(CLLutAccessor &&)                 = default;
+    CLLutAccessor &operator=(CLLutAccessor &&) = 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:
+    CLLut &_lut;
+};
+
+} // namespace cl
+} // namespace test
+} // namespace arm_compute
+#endif /* __ARM_COMPUTE_TEST_CL_CLLUTACCESSOR_H__ */