COMPMID-1332: Implement Slice for CL

Change-Id: I0dbc4fd7f640d31daa1970eb3da0e941cb771f2b
Reviewed-on: https://eu-gerrit-1.euhpc.arm.com/146145
Tested-by: Jenkins <bsgcomp@arm.com>
Reviewed-by: Giorgio Arena <giorgio.arena@arm.com>
Reviewed-by: Michalis Spyrou <michalis.spyrou@arm.com>

3 files changed, 99 insertions, 3 deletions

diff --git a/arm_compute/core/utils/helpers/tensor_transform.h b/arm_compute/core/utils/helpers/tensor_transform.h
index e5b32a5372..966c1f1fdf 100644
--- a/arm_compute/core/utils/helpers/tensor_transform.h
+++ b/arm_compute/core/utils/helpers/tensor_transform.h
@@ -32,12 +32,33 @@ namespace helpers
 {
 namespace tensor_transform
 {
+/** Returns the absolute ends coordinates of slice
+ *
+ * @param[in] input_shape Input tensor shape
+ * @param[in] ends        End coordinates
+ *
+ * @return Absolute end coordinate
+ */
+Coordinates slice_absolute_end_coords(TensorShape input_shape, Coordinates ends);
+
+/** Computes output shape of slice
+ *
+ * @warning Ends must be non-negative
+ *
+ * @param[in] input_shape Input tensor shape
+ * @param[in] starts      Start coordinates
+ * @param[in] ends_abs    Absolute end coordinates
+ *
+ * @return The output tensor shape
+ */
+TensorShape compute_slice_output_shape(TensorShape input_shape, Coordinates starts, Coordinates ends_abs);
+
 /** Returns the absolute start coordinates of strided slice
  *
  * @param[in] input_shape Input tensor shape
  * @param[in] starts      Start coordinates
  * @param[in] strides     Slice strides
- * @param[in] begin_mask  (Optional) If the ith bit of begin_mask is set, begin[i] is ignored and
+ * @param[in] begin_mask  (Optional) If the ith bit of begin_mask is set, starts[i] is ignored and
  *                        the fullest possible range in that dimension is used instead.
  *
  * @return Absolute start coordinates
@@ -46,6 +67,8 @@ Coordinates strided_slice_absolute_start_coords(TensorShape input_shape, Coordin
 
 /** Returns the absolute ends coordinates of strided slice
  *
+ * @warning Starts must be non-negative
+ *
  * @param[in] input_shape      Input tensor shape
  * @param[in] starts_abs       Absolute start coordinates
  * @param[in] ends             End coordinates
@@ -53,7 +76,7 @@ Coordinates strided_slice_absolute_start_coords(TensorShape input_shape, Coordin
  * @param[in] end_mask         (Optional) If the ith bit of end_mask is set, end[i] is ignored and
  *                             the fullest possible range in that dimension is used instead.
  * @param[in] shrink_axis_mask (Optional) If the ith bit of shrink_axis_mask is set, it implies that the ith specification shrinks the dimensionality by 1.
- *                             A slice of size 1 starting from begin[i] in the dimension must be preserved.
+ *                             A slice of size 1 starting from starts[i] in the dimension must be preserved.
  *
  * @return Absolute end coordinates
  */
@@ -68,7 +91,10 @@ Coordinates strided_slice_absolute_end_coords(TensorShape input_shape, Coordinat
  */
 Coordinates strided_slice_strides(TensorShape input_shape, Coordinates strides);
 
-/** Computes output shape of a strided slice
+/** Computes output shape of strided slice
+ *
+ * @warning Starts and ends must be non-negative
+ * @warning Starts, ends and final strides should have the same dimensions as the input shape
  *
  * @param[in] input_shape   Input tensor shape
  * @param[in] starts_abs    Absolute start coordinates
diff --git a/arm_compute/runtime/CL/CLFunctions.h b/arm_compute/runtime/CL/CLFunctions.h
index 76c2128f2c..d2bfdfd7cb 100644
--- a/arm_compute/runtime/CL/CLFunctions.h
+++ b/arm_compute/runtime/CL/CLFunctions.h
@@ -106,6 +106,7 @@
 #include "arm_compute/runtime/CL/functions/CLReshapeLayer.h"
 #include "arm_compute/runtime/CL/functions/CLScale.h"
 #include "arm_compute/runtime/CL/functions/CLScharr3x3.h"
+#include "arm_compute/runtime/CL/functions/CLSlice.h"
 #include "arm_compute/runtime/CL/functions/CLSobel3x3.h"
 #include "arm_compute/runtime/CL/functions/CLSobel5x5.h"
 #include "arm_compute/runtime/CL/functions/CLSobel7x7.h"
diff --git a/arm_compute/runtime/CL/functions/CLSlice.h b/arm_compute/runtime/CL/functions/CLSlice.h
new file mode 100644
index 0000000000..acd4f0d3ad
--- /dev/null
+++ b/arm_compute/runtime/CL/functions/CLSlice.h
@@ -0,0 +1,69 @@
+/*
+ * Copyright (c) 2018 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 __ARM_COMPUTE_CL_SLICE_H__
+#define __ARM_COMPUTE_CL_SLICE_H__
+
+#include "arm_compute/runtime/CL/ICLSimpleFunction.h"
+
+namespace arm_compute
+{
+// Forward Declarations
+class ICLTensor;
+
+/** Basic function to perform tensor slicing */
+class CLSlice : public ICLSimpleFunction
+{
+public:
+    /** Configure kernel
+     *
+     * @note Supported tensor rank: up to 4
+     * @note Start indices must be non-negative. 0 <= starts[i]
+     * @note End coordinates can be negative, which represents the number of elements before the end of that dimension.
+     * @note End indices are not inclusive unless negative.
+     *
+     * @param[in]  input  Source tensor. Data type supported: U8/S8/QASYMM8/U16/S16/U32/S32/F16/F32
+     * @param[out] output Destination tensor. Data type supported: Same as @p input
+     * @param[in]  starts The starts of the dimensions of the input tensor to be sliced. The length must be of rank(input).
+     * @param[in]  ends   The ends of the dimensions of the input tensor to be sliced. The length must be of rank(input).
+     */
+    void configure(const ICLTensor *input, ICLTensor *output, const Coordinates &starts, const Coordinates &ends);
+
+    /** Static function to check if given info will lead to a valid configuration of @ref CLSlice
+     *
+     * @note Supported tensor rank: up to 4
+     * @note Start indices must be non-negative. 0 <= starts[i]
+     * @note End coordinates can be negative, which represents the number of elements before the end of that dimension.
+     * @note End indices are not inclusive unless negative.
+     *
+     * @param[in] input  Source tensor info. Data type supported: U8/S8/QASYMM8/U16/S16/U32/S32/F16/F32
+     * @param[in] output Destination tensor info. Data type supported: Same as @p input
+     * @param[in] starts The starts of the dimensions of the input tensor to be sliced. The length must be of rank(input).
+     * @param[in] ends   The ends of the dimensions of the input tensor to be sliced. The length must be of rank(input).
+     *
+     * @return A status
+     */
+    static Status validate(const ITensorInfo *input, const ITensorInfo *output, const Coordinates &starts, const Coordinates &ends);
+};
+} // namespace arm_compute
+#endif /* __ARM_COMPUTE_CL_SLICE_H__ */