Prepare the basic types for the compute kernel writer (CKW)

- Add TensorInfo
- Add TileInfo
- Add CLTile
- Add basic utility methods to get tensor components
- Add unit tests

Resolves COMPMID-5782, COMPMID-5785

Signed-off-by: Gian Marco Iodice <gianmarco.iodice@arm.com>
Change-Id: I5e590bddd240d2f1fc876cac7129947558d7d53b
Reviewed-on: https://eu-gerrit-1.euhpc.arm.com/c/VisualCompute/ComputeLibrary/+/486221
Tested-by: bsgcomp <bsgcomp@arm.com>
Reviewed-by: Jakub Sujak <jakub.sujak@arm.com>
Reviewed-by: Pablo Tello <pablo.tello@arm.com>
Comments-Addressed: bsgcomp <bsgcomp@arm.com>
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/9687
Reviewed-by: Viet-Hoa Do <viet-hoa.do@arm.com>
Reviewed-by: Pablo Marquez Tello <pablo.tello@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Benchmark: Arm Jenkins <bsgcomp@arm.com>
diff --git a/compute_kernel_writer/src/ITile.h b/compute_kernel_writer/src/ITile.h
new file mode 100644
index 0000000..283e6fa
--- /dev/null
+++ b/compute_kernel_writer/src/ITile.h
@@ -0,0 +1,134 @@
+/*
+ * Copyright (c) 2023 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 COMPUTE_KERNEL_WRITER_SRC_ITILE_H
+#define COMPUTE_KERNEL_WRITER_SRC_ITILE_H
+
+#include "ckw/TileInfo.h"
+
+#include <string>
+#include <vector>
+
+namespace ckw
+{
+/** Tile descriptor which reports the underlying datatype and vector length */
+struct TileVariableDescriptor
+{
+    DataType dt { DataType::Unknown };  /** Data type  */
+    int32_t  len { 1 };                 /** Number of elements in a single variable. For example, 1 for scalar  */
+};
+
+/** Tile variable */
+struct TileVariable
+{
+    std::string            str {""}; /** Tile variable as a string */
+    TileVariableDescriptor desc {};  /** Tile value descriptor which reports the datatype and vector length */
+};
+
+/** Tile base class.
+ *  A Tile is a collection of variables (either program variables or constants) used to express a 2D data.
+ */
+class ITile
+{
+public:
+    virtual ~ITile() = default;
+    /** Method to get all TileVariable objects
+     *
+     * @return a vector containing all @ref TileVariable objects
+     */
+    virtual std::vector<TileVariable> all() const = 0;
+    /** Method to get the name of the tile.
+     *
+     * @return the name of the tile
+     */
+    std::string name() const
+    {
+        return _basename;
+    }
+    /** Method to get the tile info
+     *
+     * @return the @ref TileInfo
+     */
+    TileInfo info() const
+    {
+        return _info;
+    }
+    /** Method to know whether the tile is assignable or not.
+     *  For example, a constant tile is not assignable.
+     *
+     * @return true if the tile is assignable
+     */
+    virtual bool is_assignable() const = 0;
+
+protected:
+    TileInfo    _info { DataType::Unknown };    // Tile info
+    std::string _basename { "" };               // Tile name
+};
+
+/** Tile base class to store scalar variables.
+ */
+class IScalarTile : public ITile
+{
+public:
+    virtual ~IScalarTile() = default;
+    /** Method to get the scalar variable from a tile as a string
+     * @param[in] col Tile column. If out-of-bound, the column is clamped to the nearest valid edge
+     * @param[in] row Tile row. If out-of-bound, the row is clamped to the nearest valid edge
+     *
+     * @return the @ref TileVariable
+     */
+    virtual TileVariable scalar(int32_t col, int32_t row) const = 0;
+};
+
+/** Tile base class to store vector variables. It derives from IScalarTile since we can still access the scalar variable
+ */
+class IVectorTile : public IScalarTile
+{
+public:
+    virtual ~IVectorTile() = default;
+    /** Method to get the vector variable from a tile.
+     *  The user can query the list of supported vector lengths through the supported_vector_lengths() method.
+     *
+     * @param[in] row Tile row. If out-of-bound, the row is clamped to the nearest valid edge
+     *
+     * @return the vector variable as a @ref TileVariable
+     */
+    virtual TileVariable vector(int32_t row) const = 0;
+    /** Method to get a sub-vector variable. The length of the sub-vector must be supported by the derived IVectorTile class
+     *
+     * @param[in] col_start Tile starting column to get the sub-vector. If out-of-bound, the derived IVectorTile class may throw an assert.
+     * @param[in] width     The width of the sub-vector. The width must be supported by the derived IVectorTile class and the last element must be in-bound.
+     * @param[in] row       Tile row. If out-of-bound, the row is clamped to the nearest valid edge
+     *
+     * @return the vector variable as a @ref TileVariable
+     */
+    virtual TileVariable vector(int32_t col_start, int32_t width, int32_t row) const = 0;
+    /** Method to get the supported vector length.
+     *
+     * @return a vector containing the supported vector lengths
+     */
+    virtual std::vector<int32_t> supported_vector_lengths() const = 0;
+};
+} // namespace ckw
+
+#endif /* COMPUTE_KERNEL_WRITER_SRC_ITILE_H */