1 /* 2 * Copyright (c) 2019-2020 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 ARM_COMPUTE_UTILS_HELPERS_FFT_H 25 #define ARM_COMPUTE_UTILS_HELPERS_FFT_H 26 27 #include <set> 28 #include <vector> 29 30 namespace arm_compute 31 { 32 namespace helpers 33 { 34 namespace fft 35 { 36 /** Decompose a given 1D input size using the provided supported factors. 37 * 38 * @param[in] N Input size to be decomposed. 39 * @param[in] supported_factors Supported factors that can be used for decomposition. 40 * 41 * @return A vector with the stages of the decomposition. Will be empty if decomposition failed. 42 */ 43 std::vector<unsigned int> decompose_stages(unsigned int N, const std::set<unsigned int> &supported_factors); 44 /** Calculate digit reverse index vector given fft size and the decomposed stages 45 * 46 * @param N Input size to calculate digit reverse for 47 * @param fft_stages A vector with the FFT decomposed stages 48 * 49 * @return A vector with the digit reverse indices. Will be empty if it failed. 50 */ 51 std::vector<unsigned int> digit_reverse_indices(unsigned int N, const std::vector<unsigned int> &fft_stages); 52 } // namespace fft 53 } // namespace helpers 54 } // namespace arm_compute 55 #endif /* ARM_COMPUTE_UTILS_HELPERS_FFT_H */ 56