Generalization of CLTuner

Rename lws to tuning parameters in functions used externally
Add new generalized objects for the OpenCL Tuner to accommodate
further possible tuning parameters

Resolves: COMPMID-3935

Change-Id: I0f2a0f89bca5dae4a4e4adce2f7c7cae32ecb84a
Signed-off-by: Manuel Bottini <manuel.bottini@arm.com>
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/4584
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Georgios Pinitas <georgios.pinitas@arm.com>

5 files changed, 309 insertions, 146 deletions

diff --git a/src/core/NEON/kernels/NESelectKernel.cpp b/src/core/NEON/kernels/NESelectKernel.cpp
index 9cf9b98a0c..1d5f2b61a1 100644
--- a/src/core/NEON/kernels/NESelectKernel.cpp
+++ b/src/core/NEON/kernels/NESelectKernel.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018-2020 Arm Limited.
+ * Copyright (c) 2018-2021 Arm Limited.
  *
  * SPDX-License-Identifier: MIT
  *
@@ -34,7 +34,6 @@
 #include "src/core/NEON/wrapper/wrapper.h"
 #include "src/core/helpers/AutoConfiguration.h"
 #include "src/core/helpers/WindowHelpers.h"
-#include "utils/TypePrinter.h"
 
 #include <arm_neon.h>
 #include <map>
diff --git a/src/graph/backends/CL/CLDeviceBackend.cpp b/src/graph/backends/CL/CLDeviceBackend.cpp
index bc7bbddbd8..50dd799ee1 100644
--- a/src/graph/backends/CL/CLDeviceBackend.cpp
+++ b/src/graph/backends/CL/CLDeviceBackend.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018-2020 Arm Limited.
+ * Copyright (c) 2018-2021 Arm Limited.
  *
  * SPDX-License-Identifier: MIT
  *
@@ -71,11 +71,7 @@ CLDeviceBackend::CLDeviceBackend()
 
 CLDeviceBackend::~CLDeviceBackend()
 {
-    // TODO (geopin01) : Shouldn't call non exception safe stuff here
-    if(_tuner.tune_new_kernels() && !_tuner.lws_table().empty() && !_tuner_file.empty())
-    {
-        _tuner.save_to_file(_tuner_file);
-    }
+    _tuner.save_to_file(_tuner_file);
 }
 
 void CLDeviceBackend::set_kernel_tuning(bool enable_tuning)
@@ -117,6 +113,7 @@ void CLDeviceBackend::setup_backend_context(GraphContext &ctx)
 
     // Setup tuner
     _tuner_file = ctx.config().tuner_file;
+
     // Load tuner data if available
     if(file_exists(_tuner_file))
     {
diff --git a/src/runtime/CL/CLTuner.cpp b/src/runtime/CL/CLTuner.cpp
index ed85e606cf..bcc50f6c28 100644
--- a/src/runtime/CL/CLTuner.cpp
+++ b/src/runtime/CL/CLTuner.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017-2020 Arm Limited.
+ * Copyright (c) 2017-2021 Arm Limited.
  *
  * SPDX-License-Identifier: MIT
  *
@@ -22,7 +22,7 @@
  * SOFTWARE.
  */
 #include "arm_compute/runtime/CL/CLTuner.h"
-#include "arm_compute/runtime/CL/tuners/CLLWSList.h"
+#include "arm_compute/runtime/CL/tuners/CLTuningParametersList.h"
 
 #include "arm_compute/core/Error.h"
 #include "arm_compute/runtime/CL/CLScheduler.h"
@@ -38,8 +38,8 @@
 
 namespace arm_compute
 {
-CLTuner::CLTuner(bool tune_new_kernels)
-    : real_clEnqueueNDRangeKernel(nullptr), _lws_table(), _kernel_event(), _tune_new_kernels(tune_new_kernels), _tuner_mode(CLTunerMode::NORMAL)
+CLTuner::CLTuner(bool tune_new_kernels, CLTuningInfo tuning_info)
+    : real_clEnqueueNDRangeKernel(nullptr), _tuning_params_table(), _lws_table(), _kernel_event(), _tune_new_kernels(tune_new_kernels), _tuning_info(tuning_info), _tuner_mode(CLTunerMode::NORMAL)
 {
 }
 
@@ -65,6 +65,7 @@ void CLTuner::set_tuner_mode(CLTunerMode mode)
 {
     _tuner_mode = mode;
 }
+
 CLTunerMode CLTuner::get_tuner_mode() const
 {
     return _tuner_mode;
@@ -89,36 +90,41 @@ void CLTuner::tune_kernel_dynamic(ICLKernel &kernel, ITensorPack &tensors)
     // Check if we need to find the Optimal LWS. If the kernel's config_id is equal to default_config_id, the kernel does not require to be tuned
     if(kernel.config_id() != arm_compute::default_config_id)
     {
-        auto p = _lws_table.find(config_id);
+        auto p = _tuning_params_table.find(config_id);
 
-        if(p == _lws_table.end())
+        if(p == _tuning_params_table.end())
         {
             if(_tune_new_kernels)
             {
                 // Find the optimal LWS for the kernel
-                cl::NDRange opt_lws = find_optimal_lws(kernel, tensors);
+                CLTuningParams opt_tuning_params = find_optimal_tuning_params(kernel, tensors);
 
                 // Insert the optimal LWS in the table
-                add_lws_to_table(config_id, opt_lws);
+                add_tuning_params(config_id, opt_tuning_params);
 
                 // Set Local-Workgroup-Size
-                kernel.set_lws_hint(opt_lws);
+                kernel.set_lws_hint(opt_tuning_params.get_lws());
             }
         }
         else
         {
             // Set Local-Workgroup-Size
-            kernel.set_lws_hint(p->second);
+            kernel.set_lws_hint(p->second.get_lws());
         }
     }
 }
 
 void CLTuner::add_lws_to_table(const std::string &kernel_id, cl::NDRange optimal_lws)
 {
-    _lws_table.emplace(kernel_id, optimal_lws);
+    add_tuning_params(kernel_id, CLTuningParams(optimal_lws));
 }
 
-cl::NDRange CLTuner::find_optimal_lws(ICLKernel &kernel, ITensorPack &tensors)
+void CLTuner::add_tuning_params(const std::string &kernel_id, CLTuningParams optimal_tuning_params)
+{
+    _tuning_params_table.emplace(kernel_id, optimal_tuning_params);
+}
+
+CLTuningParams CLTuner::find_optimal_tuning_params(ICLKernel &kernel, ITensorPack &tensors)
 {
     // Profiling queue
     cl::CommandQueue queue_profiler;
@@ -185,11 +191,11 @@ cl::NDRange CLTuner::find_optimal_lws(ICLKernel &kernel, ITensorPack &tensors)
 
     cl::NDRange opt_lws = cl::NullRange;
 
-    // Construct the list of LWS values to be tested based on the tuner mode.
-    auto lws_list = cl_tuner::CLLWSListFactory::get_lws_list(_tuner_mode, gws);
+    // Construct the list of tuning parameters values to be tested based on the tuner mode.
+    auto lws_list = cl_tuner::get_tuning_parameters_list(_tuner_mode, gws);
     for(size_t i = 0; i < lws_list->size(); ++i)
     {
-        cl::NDRange lws_test    = (*lws_list)[i];
+        cl::NDRange lws_test    = (*lws_list)[i].get_lws();
         auto        x           = lws_test[0];
         auto        y           = lws_test[1];
         auto        z           = lws_test[2];
@@ -223,21 +229,39 @@ cl::NDRange CLTuner::find_optimal_lws(ICLKernel &kernel, ITensorPack &tensors)
 
     // Restore real function
     CLSymbols::get().clEnqueueNDRangeKernel_ptr = real_clEnqueueNDRangeKernel;
-
-    return opt_lws;
+    return CLTuningParams(opt_lws);
 }
 
 void CLTuner::import_lws_table(const std::unordered_map<std::string, cl::NDRange> &lws_table)
 {
-    _lws_table.clear();
-    _lws_table = lws_table;
+    _tuning_params_table.clear();
+    for(auto && params : lws_table)
+    {
+        add_tuning_params(params.first, CLTuningParams(params.second));
+    }
 }
 
-const std::unordered_map<std::string, cl::NDRange> &CLTuner::lws_table() const
+const std::unordered_map<std::string, cl::NDRange> &CLTuner::lws_table()
 {
+    _lws_table.clear();
+    for(auto && params : _tuning_params_table)
+    {
+        _lws_table.emplace(params.first, params.second.get_lws());
+    }
     return _lws_table;
 }
 
+const std::unordered_map<std::string, CLTuningParams> &CLTuner::tuning_params_table() const
+{
+    return _tuning_params_table;
+}
+
+void CLTuner::import_tuning_params(const std::unordered_map<std::string, CLTuningParams> &tuning_params_table)
+{
+    _tuning_params_table.clear();
+    _tuning_params_table = tuning_params_table;
+}
+
 void CLTuner::load_from_file(const std::string &filename)
 {
     std::ifstream fs;
@@ -272,20 +296,28 @@ void CLTuner::load_from_file(const std::string &filename)
         {
             lws = cl::NullRange;
         }
-        add_lws_to_table(kernel_id, lws);
+        add_tuning_params(kernel_id, lws);
     }
     fs.close();
+    _tuning_info.tune_lws = true;
 }
 
-void CLTuner::save_to_file(const std::string &filename) const
+bool CLTuner::save_to_file(const std::string &filename) const
 {
+    if(!_tune_new_kernels || _tuning_params_table.empty() || filename.empty())
+    {
+        return false;
+    }
+
     std::ofstream fs;
     fs.exceptions(std::ifstream::failbit | std::ifstream::badbit);
     fs.open(filename, std::ios::out);
-    for(auto const &kernel_data : _lws_table)
+    for(auto const &kernel_data : _tuning_params_table)
     {
-        fs << kernel_data.first << ";" << kernel_data.second[0] << ";" << kernel_data.second[1] << ";" << kernel_data.second[2] << std::endl;
+        const cl::NDRange lws = CLTuningParams(kernel_data.second).get_lws();
+        fs << kernel_data.first << ";" << lws[0] << ";" << lws[1] << ";" << lws[2] << std::endl;
     }
     fs.close();
+    return true;
 }
 } // namespace arm_compute
diff --git a/src/runtime/CL/tuners/CLLWSList.cpp b/src/runtime/CL/tuners/CLLWSList.cpp
deleted file mode 100644
index c537f15bf0..0000000000
--- a/src/runtime/CL/tuners/CLLWSList.cpp
+++ /dev/null
@@ -1,114 +0,0 @@
-/*
- * Copyright (c) 2019 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.
- */
-#include "arm_compute/runtime/CL/tuners/CLLWSList.h"
-
-namespace arm_compute
-{
-namespace cl_tuner
-{
-size_t CLLWSList::size()
-{
-    return search_space_shape.total_size();
-}
-
-cl::NDRange CLLWSListExhaustive::operator[](size_t index)
-{
-    ARM_COMPUTE_ERROR_ON(index >= size());
-    auto coords = index2coords(search_space_shape, index);
-    return cl::NDRange{ coords[0] + 1U, coords[1] + 1U, coords[2] + 1U };
-}
-
-CLLWSListExhaustive::CLLWSListExhaustive(const cl::NDRange &gws)
-{
-    ARM_COMPUTE_UNUSED(gws);
-    search_space_shape = TensorShape(max_lws_supported_x,
-                                     max_lws_supported_y,
-                                     max_lws_supported_z);
-}
-
-cl::NDRange CLLWSListNormal::operator[](size_t index)
-{
-    ARM_COMPUTE_ERROR_ON(index >= size());
-    auto coords = index2coords(search_space_shape, index);
-    return cl::NDRange{ _lws_x[coords[0]], _lws_y[coords[1]], _lws_z[coords[2]] };
-}
-
-CLLWSListNormal::CLLWSListNormal(const cl::NDRange &gws)
-{
-    auto lws_x_max = std::min(static_cast<unsigned int>(gws[0]), max_lws_supported_x);
-    auto lws_y_max = std::min(static_cast<unsigned int>(gws[1]), max_lws_supported_y);
-    auto lws_z_max = std::min(static_cast<unsigned int>(gws[2]), max_lws_supported_z);
-
-    // Initialize the LWS values to test
-    initialize_lws_values(_lws_x, gws[0], lws_x_max, gws[2] > 16); // Explore lws that are not factors of gws only when gws[2] > 16
-    initialize_lws_values(_lws_y, gws[1], lws_y_max, gws[2] > 16); // Explore lws that are not factors of gws only when gws[2] > 16
-    initialize_lws_values(_lws_z, gws[2], lws_z_max, false);
-
-    search_space_shape = TensorShape(_lws_x.size(), _lws_y.size(), _lws_z.size());
-}
-
-void CLLWSListNormal::initialize_lws_values(std::vector<unsigned int> &lws, unsigned int gws, unsigned int lws_max, bool mod_let_one)
-{
-    lws.push_back(1);
-
-    for(unsigned int i = 2; i <= lws_max; ++i)
-    {
-        // Power of two condition
-        const bool is_power_of_two = (i & (i - 1)) == 0;
-
-        // Condition for the module accordingly with the mod_let_one flag
-        const bool mod_cond = mod_let_one ? (gws % i) <= 1 : (gws % i) == 0;
-
-        if(mod_cond || is_power_of_two)
-        {
-            lws.push_back(i);
-        }
-    }
-}
-
-CLLWSListRapid::CLLWSListRapid(const cl::NDRange &gws)
-{
-    auto lws_x_max = std::min(static_cast<unsigned int>(gws[0]), 8u); // Limit exploration to 1 - 8
-    auto lws_y_max = std::min(static_cast<unsigned int>(gws[1]), 4u); // Limit exploration to 1 - 4
-    auto lws_z_max = std::min(static_cast<unsigned int>(gws[2]), 4u); // Limit exploration to 1 - 4
-
-    // Initialize the LWS values to test
-    initialize_lws_values(_lws_x, lws_x_max);
-    initialize_lws_values(_lws_y, lws_y_max);
-    initialize_lws_values(_lws_z, lws_z_max);
-
-    search_space_shape = TensorShape(_lws_x.size(), _lws_y.size(), _lws_z.size());
-}
-
-void CLLWSListRapid::initialize_lws_values(std::vector<unsigned int> &lws, unsigned int lws_max)
-{
-    lws.push_back(1);
-
-    for(unsigned int i = 2; i <= lws_max; i *= 4)
-    {
-        lws.push_back(i);
-    }
-}
-} // namespace cl_tuner
-} // namespace arm_compute
diff --git a/src/runtime/CL/tuners/CLTuningParametersList.cpp b/src/runtime/CL/tuners/CLTuningParametersList.cpp
new file mode 100644
index 0000000000..7f63078192
--- /dev/null
+++ b/src/runtime/CL/tuners/CLTuningParametersList.cpp
@@ -0,0 +1,249 @@
+/*
+ * Copyright (c) 2019-2021 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.
+ */
+#include "arm_compute/runtime/CL/tuners/CLTuningParametersList.h"
+
+namespace arm_compute
+{
+namespace cl_tuner
+{
+constexpr unsigned int max_lws_supported_x{ 64u };
+constexpr unsigned int max_lws_supported_y{ 32u };
+constexpr unsigned int max_lws_supported_z{ 32u };
+
+/** Non instantiable base class for Tuning parameters combinations that use Index2Cooard mapping */
+class CLTuningParametersList : public ICLTuningParametersList
+{
+protected:
+    /* Shape of 3-D search space */
+    TensorShape search_space_shape{ 0, 0, 0 };
+
+    /** Constructor */
+    CLTuningParametersList() = default;
+    /** Copy Constructor */
+    CLTuningParametersList(const CLTuningParametersList &) = default;
+    /** Move Constructor */
+    CLTuningParametersList(CLTuningParametersList &&) noexcept(true) = default;
+    /** Assignment */
+    CLTuningParametersList &operator=(const CLTuningParametersList &) = default;
+    /** Move Assignment */
+    CLTuningParametersList &operator=(CLTuningParametersList &&) noexcept(true) = default;
+    /** Destructor */
+    virtual ~CLTuningParametersList() = default;
+
+    // Inherited methods overridden:
+    virtual size_t size() override;
+};
+
+/** Exhaustive list of all possible Tuning parameters (lws) values */
+class CLTuningParametersListExhaustive : public CLTuningParametersList
+{
+public:
+    /** Prevent default constructor calls */
+    CLTuningParametersListExhaustive() = delete;
+    /** Constructor */
+    CLTuningParametersListExhaustive(const cl::NDRange &gws);
+    /** Copy Constructor */
+    CLTuningParametersListExhaustive(const CLTuningParametersListExhaustive &) = default;
+    /** Move Constructor */
+    CLTuningParametersListExhaustive(CLTuningParametersListExhaustive &&) noexcept(true) = default;
+    /** Assignment */
+    CLTuningParametersListExhaustive &operator=(const CLTuningParametersListExhaustive &) = default;
+    /** Move Assignment */
+    CLTuningParametersListExhaustive &operator=(CLTuningParametersListExhaustive &&) noexcept(true) = default;
+    /** Destructor */
+    ~CLTuningParametersListExhaustive() = default;
+
+    // Inherited methods overridden:
+    CLTuningParams operator[](size_t) override;
+};
+
+/** A subset of LWS values that are either factors of gws when gws[2] < 16 or power of 2 */
+class CLTuningParametersListNormal : public CLTuningParametersList
+{
+public:
+    /** Constructor */
+    CLTuningParametersListNormal(const cl::NDRange &gws);
+    /** Copy Constructor */
+    CLTuningParametersListNormal(const CLTuningParametersListNormal &) = default;
+    /** Move Constructor */
+    CLTuningParametersListNormal(CLTuningParametersListNormal &&) noexcept(true) = default;
+    /** Assignment */
+    CLTuningParametersListNormal &operator=(const CLTuningParametersListNormal &) = default;
+    /** Move Assignment */
+    CLTuningParametersListNormal &operator=(CLTuningParametersListNormal &&) noexcept(true) = default;
+    /** Destructor */
+    ~CLTuningParametersListNormal() = default;
+
+    // Inherited methods overridden:
+    CLTuningParams operator[](size_t) override;
+
+protected:
+    std::vector<unsigned int> _lws_x{};
+    std::vector<unsigned int> _lws_y{};
+    std::vector<unsigned int> _lws_z{};
+
+    /** Prevent default constructor calls */
+    CLTuningParametersListNormal() = default;
+
+private:
+    /** Utility function used to initialize the LWS values to test.
+     *  Only the LWS values which are power of 2 or satisfy the modulo conditions with GWS are taken into account by the CLTuner
+     *
+     * @param[in, out] lws         Vector of LWS to test
+     * @param[in]      gws         Size of the specific GWS
+     * @param[in]      lws_max     Max LWS value allowed to be tested
+     * @param[in]      mod_let_one True if the results of the modulo operation between gws and the lws can be less than one.
+     */
+    void initialize_lws_values(std::vector<unsigned int> &lws, unsigned int gws, unsigned int lws_max, bool mod_let_one);
+};
+
+/** A minimal subset of LWS values that only have 1,2 and 4/8 */
+class CLTuningParametersListRapid : public CLTuningParametersListNormal
+{
+public:
+    /** Prevent default constructor calls */
+    CLTuningParametersListRapid() = delete;
+    /** Constructor */
+    CLTuningParametersListRapid(const cl::NDRange &gws);
+    /** Copy Constructor */
+    CLTuningParametersListRapid(const CLTuningParametersListRapid &) = default;
+    /** Move Constructor */
+    CLTuningParametersListRapid(CLTuningParametersListRapid &&) noexcept(true) = default;
+    /** Assignment */
+    CLTuningParametersListRapid &operator=(const CLTuningParametersListRapid &) = default;
+    /** Move Assignment */
+    CLTuningParametersListRapid &operator=(CLTuningParametersListRapid &&) noexcept(true) = default;
+    /** Destructor */
+    virtual ~CLTuningParametersListRapid() = default;
+
+private:
+    /** Utility function used to initialize the LWS values to test.
+     *  Only the LWS values that have 1,2 and 4/8 for each dimension are taken into account by the CLTuner
+     *
+     * @param[in, out] lws     Vector of LWS to test
+     * @param[in]      lws_max Max LWS value allowed to be tested
+     */
+    void initialize_lws_values(std::vector<unsigned int> &lws, unsigned int lws_max);
+};
+
+size_t CLTuningParametersList::size()
+{
+    return search_space_shape.total_size();
+}
+
+CLTuningParams CLTuningParametersListExhaustive::operator[](size_t index)
+{
+    ARM_COMPUTE_ERROR_ON(index >= size());
+    auto coords = index2coords(search_space_shape, index);
+    return CLTuningParams(coords[0] + 1U, coords[1] + 1U, coords[2] + 1U);
+}
+
+CLTuningParametersListExhaustive::CLTuningParametersListExhaustive(const cl::NDRange &gws)
+{
+    ARM_COMPUTE_UNUSED(gws);
+    search_space_shape = TensorShape(max_lws_supported_x,
+                                     max_lws_supported_y,
+                                     max_lws_supported_z);
+}
+
+CLTuningParams CLTuningParametersListNormal::operator[](size_t index)
+{
+    ARM_COMPUTE_ERROR_ON(index >= size());
+    auto coords = index2coords(search_space_shape, index);
+    return CLTuningParams(_lws_x[coords[0]], _lws_y[coords[1]], _lws_z[coords[2]]);
+}
+
+CLTuningParametersListNormal::CLTuningParametersListNormal(const cl::NDRange &gws)
+{
+    auto lws_x_max = std::min(static_cast<unsigned int>(gws[0]), max_lws_supported_x);
+    auto lws_y_max = std::min(static_cast<unsigned int>(gws[1]), max_lws_supported_y);
+    auto lws_z_max = std::min(static_cast<unsigned int>(gws[2]), max_lws_supported_z);
+
+    // Initialize the LWS values to test
+    initialize_lws_values(_lws_x, gws[0], lws_x_max, gws[2] > 16); // Explore lws that are not factors of gws only when gws[2] > 16
+    initialize_lws_values(_lws_y, gws[1], lws_y_max, gws[2] > 16); // Explore lws that are not factors of gws only when gws[2] > 16
+    initialize_lws_values(_lws_z, gws[2], lws_z_max, false);
+
+    search_space_shape = TensorShape(_lws_x.size(), _lws_y.size(), _lws_z.size());
+}
+
+void CLTuningParametersListNormal::initialize_lws_values(std::vector<unsigned int> &lws, unsigned int gws, unsigned int lws_max, bool mod_let_one)
+{
+    lws.push_back(1);
+
+    for(unsigned int i = 2; i <= lws_max; ++i)
+    {
+        // Power of two condition
+        const bool is_power_of_two = (i & (i - 1)) == 0;
+
+        // Condition for the module accordingly with the mod_let_one flag
+        const bool mod_cond = mod_let_one ? (gws % i) <= 1 : (gws % i) == 0;
+
+        if(mod_cond || is_power_of_two)
+        {
+            lws.push_back(i);
+        }
+    }
+}
+
+CLTuningParametersListRapid::CLTuningParametersListRapid(const cl::NDRange &gws)
+{
+    auto lws_x_max = std::min(static_cast<unsigned int>(gws[0]), 8u); // Limit exploration to 1 - 8
+    auto lws_y_max = std::min(static_cast<unsigned int>(gws[1]), 4u); // Limit exploration to 1 - 4
+    auto lws_z_max = std::min(static_cast<unsigned int>(gws[2]), 4u); // Limit exploration to 1 - 4
+
+    // Initialize the LWS values to test
+    initialize_lws_values(_lws_x, lws_x_max);
+    initialize_lws_values(_lws_y, lws_y_max);
+    initialize_lws_values(_lws_z, lws_z_max);
+
+    search_space_shape = TensorShape(_lws_x.size(), _lws_y.size(), _lws_z.size());
+}
+
+void CLTuningParametersListRapid::initialize_lws_values(std::vector<unsigned int> &lws, unsigned int lws_max)
+{
+    lws.push_back(1);
+
+    for(unsigned int i = 2; i <= lws_max; i *= 4)
+    {
+        lws.push_back(i);
+    }
+}
+
+std::unique_ptr<ICLTuningParametersList> get_tuning_parameters_list(CLTunerMode mode, const cl::NDRange &gws)
+{
+    switch(mode)
+    {
+        case CLTunerMode::EXHAUSTIVE:
+            return std::make_unique<CLTuningParametersListExhaustive>(gws);
+        case CLTunerMode::NORMAL:
+            return std::make_unique<CLTuningParametersListNormal>(gws);
+        case CLTunerMode::RAPID:
+            return std::make_unique<CLTuningParametersListRapid>(gws);
+        default:
+            return nullptr;
+    }
+}
+} // namespace cl_tuner
+} // namespace arm_compute