COMPMID-2240 Implement DEPTH_TO_SPACE for NEON

Change-Id: I705aa0f804093c3628c691e46cca475f2819dc65
Signed-off-by: Michalis Spyrou <michalis.spyrou@arm.com>
Reviewed-on: https://review.mlplatform.org/c/1198
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Giuseppe Rossini <giuseppe.rossini@arm.com>
Tested-by: Arm Jenkins <bsgcomp@arm.com>
diff --git a/tests/validation/reference/DepthToSpaceLayer.cpp b/tests/validation/reference/DepthToSpaceLayer.cpp
new file mode 100644
index 0000000..4135ce5
--- /dev/null
+++ b/tests/validation/reference/DepthToSpaceLayer.cpp
@@ -0,0 +1,75 @@
+/*
+ * 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 "DepthToSpaceLayer.h"
+
+#include "tests/validation/Helpers.h"
+
+namespace arm_compute
+{
+namespace test
+{
+namespace validation
+{
+namespace reference
+{
+// Batch to Space
+template <typename T>
+SimpleTensor<T> depth_to_space(const SimpleTensor<T> &src, const TensorShape &dst_shape, int32_t block_shape)
+{
+    ARM_COMPUTE_ERROR_ON(block_shape <= 0);
+    SimpleTensor<T> result(dst_shape, src.data_type());
+
+    int        in_pos     = 0;
+    const auto width_in   = static_cast<int>(src.shape()[0]);
+    const auto height_in  = static_cast<int>(src.shape()[1]);
+    const auto channel_in = static_cast<int>(src.shape()[2]);
+    const auto batch_in   = static_cast<int>(src.shape()[3]);
+    const int  r          = channel_in / (block_shape * block_shape);
+
+    for(int b = 0; b < batch_in; ++b)
+    {
+        for(int z = 0; z < channel_in; ++z)
+        {
+            for(int y = 0; y < height_in; ++y)
+            {
+                for(int x = 0; x < width_in; ++x)
+                {
+                    const int out_x   = (block_shape * x + (z / r) % block_shape);
+                    const int out_y   = (block_shape * y + (z / r) / block_shape);
+                    const int out_pos = out_x + dst_shape[0] * out_y + (z % r) * dst_shape[0] * dst_shape[1] + b * dst_shape[0] * dst_shape[1] * dst_shape[2];
+                    result[out_pos]   = src[in_pos];
+                    ++in_pos;
+                }
+            }
+        }
+    }
+
+    return result;
+}
+template SimpleTensor<float> depth_to_space(const SimpleTensor<float> &src, const TensorShape &dst_shape, int32_t block_shape);
+template SimpleTensor<half> depth_to_space(const SimpleTensor<half> &src, const TensorShape &dst_shape, int32_t block_shape);
+} // namespace reference
+} // namespace validation
+} // namespace test
+} // namespace arm_compute