COMPMID-476 L2 Normalization for CL

Change-Id: I88f87173645880eb823916c5d4ac884c372a4fb4
Reviewed-on: http://mpd-gerrit.cambridge.arm.com/83269
Reviewed-by: Anthony Barbier <anthony.barbier@arm.com>
Tested-by: Kaizen <jeremy.johnson+kaizengerrit@arm.com>
diff --git a/src/runtime/CL/functions/CLReductionOperation.cpp b/src/runtime/CL/functions/CLReductionOperation.cpp
new file mode 100644
index 0000000..5bb3320
--- /dev/null
+++ b/src/runtime/CL/functions/CLReductionOperation.cpp
@@ -0,0 +1,84 @@
+/*
+ * 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.
+ */
+#include "arm_compute/runtime/CL/functions/CLReductionOperation.h"
+
+#include "arm_compute/core/CL/ICLTensor.h"
+#include "arm_compute/core/CL/kernels/CLReductionOperationKernel.h"
+#include "arm_compute/core/Error.h"
+#include "arm_compute/core/PixelValue.h"
+#include "arm_compute/core/TensorInfo.h"
+#include "arm_compute/core/Validate.h"
+#include "arm_compute/runtime/CL/CLScheduler.h"
+#include "arm_compute/runtime/Tensor.h"
+#include "support/ToolchainSupport.h"
+
+using namespace arm_compute;
+
+CLReductionOperation::CLReductionOperation()
+    : _sums_vector(), _reduction_kernels_vector(), _border_handlers_vector(), _num_of_stages()
+{
+}
+
+void CLReductionOperation::configure(ICLTensor *input, ICLTensor *output, unsigned int axis, ReductionOperation op)
+{
+    // Calculate number of WGs. 16 elements per thread, 8 threads per WG
+    unsigned int num_of_wg = ceil(input->info()->dimension(0) / 128.f);
+
+    // Calculate number of stages. First stage performs op and the rest reduction sum
+    // depending on the size of the input. Last stage should have only 1 WG.
+    _num_of_stages = num_of_wg / 128 + 2;
+
+    // Configure reduction operation kernels
+    _reduction_kernels_vector = arm_compute::support::cpp14::make_unique<CLReductionOperationKernel[]>(_num_of_stages);
+    _border_handlers_vector   = arm_compute::support::cpp14::make_unique<CLFillBorderKernel[]>(_num_of_stages);
+
+    TensorShape shape{ input->info()->tensor_shape() };
+    for(unsigned int i = 0; i < _num_of_stages - 1; i++)
+    {
+        shape.set(0, ceil(shape.x() / 128.f));
+        auto *tensor = new CLTensor;
+        tensor->allocator()->init(TensorInfo(shape, input->info()->num_channels(), input->info()->data_type(), input->info()->fixed_point_position()));
+        _sums_vector.push_back(tensor);
+    }
+
+    // Apply ReductionOperation only on first kernel
+    _reduction_kernels_vector[0].configure(input, _sums_vector.at(0), axis, op);
+    _border_handlers_vector[0].configure(input, _reduction_kernels_vector[0].border_size(), BorderMode::CONSTANT, PixelValue(0));
+    for(unsigned int i = 1; i < _num_of_stages; i++)
+    {
+        // Last sum vector is the output vector
+        _reduction_kernels_vector[i].configure(_sums_vector.at(i - 1), i == _num_of_stages - 1 ? output : _sums_vector.at(i), axis, ReductionOperation::SUM);
+        _border_handlers_vector[i].configure(_sums_vector.at(i - 1), _reduction_kernels_vector[i].border_size(), BorderMode::CONSTANT, PixelValue(0));
+        _sums_vector.at(i - 1)->allocator()->allocate();
+    }
+}
+
+void CLReductionOperation::run()
+{
+    for(unsigned int i = 0; i < _num_of_stages; ++i)
+    {
+        CLScheduler::get().enqueue(_border_handlers_vector[i], false);
+        CLScheduler::get().enqueue(_reduction_kernels_vector[i], false);
+    }
+}
\ No newline at end of file