COMPMID-3637: Move utility headers from arm_compute to src

Signed-off-by: Georgios Pinitas <georgios.pinitas@arm.com>
Change-Id: If9d6fa8c900b68c4b6fd373f2fc1f9abb83ea917
Signed-off-by: Michalis Spyrou <michalis.spyrou@arm.com>
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/4145
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Sang-Hoon Park <sang-hoon.park@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
diff --git a/src/core/helpers/Utils.h b/src/core/helpers/Utils.h
new file mode 100644
index 0000000..3c3b2b9
--- /dev/null
+++ b/src/core/helpers/Utils.h
@@ -0,0 +1,97 @@
+/*
+* Copyright (c) 2020 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 SRC_CORE_HELPERS_UTILS_H
+#define SRC_CORE_HELPERS_UTILS_H
+
+#include "arm_compute/core/ITensorInfo.h"
+
+namespace arm_compute
+{
+/** Create a strides object based on the provided strides and the tensor dimensions.
+ *
+ * @param[in] info          Tensor info object providing the shape of the tensor for unspecified strides.
+ * @param[in] stride_x      Stride to be used in X dimension (in bytes).
+ * @param[in] fixed_strides Strides to be used in higher dimensions starting at Y (in bytes).
+ *
+ * @return Strides object based on the specified strides. Missing strides are
+ *         calculated based on the tensor shape and the strides of lower dimensions.
+ */
+template <typename T, typename... Ts>
+inline Strides compute_strides(const ITensorInfo &info, T stride_x, Ts &&... fixed_strides)
+{
+    const TensorShape &shape = info.tensor_shape();
+
+    // Create strides object
+    Strides strides(stride_x, fixed_strides...);
+
+    for(size_t i = 1 + sizeof...(Ts); i < info.num_dimensions(); ++i)
+    {
+        strides.set(i, shape[i - 1] * strides[i - 1]);
+    }
+
+    return strides;
+}
+
+/** Create a strides object based on the tensor dimensions.
+ *
+ * @param[in] info Tensor info object used to compute the strides.
+ *
+ * @return Strides object based on element size and tensor shape.
+ */
+template <typename... Ts>
+inline Strides compute_strides(const ITensorInfo &info)
+{
+    return compute_strides(info, info.element_size());
+}
+
+/** Given an integer value, this function returns the next power of two
+ *
+ * @param[in] x Input value
+ *
+ * @return the next power of two
+ */
+inline unsigned int get_next_power_two(unsigned int x)
+{
+    // Decrement by 1
+    x--;
+
+    // Shift right by 1
+    x |= x >> 1u;
+    // Shift right by 2
+    x |= x >> 2u;
+    // Shift right by 4
+    x |= x >> 4u;
+    // Shift right by 8
+    x |= x >> 8u;
+    // Shift right by 16
+    x |= x >> 16u;
+
+    // Increment by 1
+    x++;
+
+    return x;
+}
+} // namespace arm_compute
+
+#endif /* SRC_CORE_HELPERS_UTILS_H */