xref: /aosp_15_r20/external/ComputeLibrary/src/core/helpers/SoftmaxHelpers.h (revision c217d954acce2dbc11938adb493fc0abd69584f3)
1 /*
2 * Copyright (c) 2020 Arm Limited.
3  *
4  * SPDX-License-Identifier: MIT
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to
8  * deal in the Software without restriction, including without limitation the
9  * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
10  * sell copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in all
14  * copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
19  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
22  * SOFTWARE.
23  */
24 #ifndef SRC_CORE_HELPERS_SOFTMAXHELPERS_H
25 #define SRC_CORE_HELPERS_SOFTMAXHELPERS_H
26 
27 #include "arm_compute/core/Types.h"
28 
29 namespace arm_compute
30 {
31 namespace softmax_helpers
32 {
33 /** Given a softmax axis, this function returns the permutation vector required to put the axis to the front
34  *
35  * @note This function assumes a tensor rank <= 4
36  *
37  * Axis selects the dimension on which softmax is performed.
38  * E.g. For input of shape 4x5x6 and axis=1, softmax will be applied to 4x6=24 vectors of size 5.
39  * Interally softmax kernels is always performed on the first dimension (front dimension), therefore permutation is
40  * required to put the dimension specified by @p axis to the first dimension.
41  *
42  * @param[in] axis Axis on which to perform softmax. Supported: 1, 2, 3 (0 implies no permutation needed)
43  *
44  * @return the permutation vector
45  */
46 PermutationVector get_permutation_vector_from_softmax_axis(size_t axis);
47 } // namespace softmax_helpers
48 } // namespace arm_compute
49 
50 #endif /* SRC_CORE_HELPERS_SOFTMAXHELPERS_H */
51