b1bb1d9815
This is done because the library is necessary to make certain FFTW functions thread safe, see #136557 as well. Also pass each library variable separately to `find_package_handle_standard_args` instead of as a list, as otherwise it won't correctly detect if `libfftw3f` or `libfftw3f_threads` is missing. This is because CMake considers a value false if it contains `-NOTFOUND` at the end, but not if it's in the middle. For example, CMake considers `.../libfftw3f.a;.../libfftw3f_threads.a;FFTW3_LIBRARY_D-NOTFOUND` to be false, but `.../libfftw3f.a;FFTW3_LIBRARY_THREADS_F-NOTFOUND;.../libfftw3.a` to be true. --- I noticed that some other find modules also have the same list issue. I guess it was done this way to make CMake print all the found libraries instead of only the first. Pull Request: https://projects.blender.org/blender/blender/pulls/136692
99 lines
2.6 KiB
C++
99 lines
2.6 KiB
C++
/* SPDX-FileCopyrightText: 2024 Blender Authors
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*
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* SPDX-License-Identifier: GPL-2.0-or-later */
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/** \file
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* \ingroup bli
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*/
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#if defined(WITH_FFTW3)
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# include <fftw3.h>
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#endif
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#include "BLI_fftw.hh"
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#include "BLI_index_range.hh"
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#include "BLI_math_vector_types.hh"
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#include "BLI_task.hh"
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#include "BLI_threads.h"
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namespace blender::fftw {
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/* Identifies if the given number is a 7-smooth number. */
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static bool is_humble_number(int n)
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{
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if (n <= 1) {
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return true;
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}
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if (n % 2 == 0) {
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return is_humble_number(n / 2);
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}
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if (n % 3 == 0) {
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return is_humble_number(n / 3);
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}
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if (n % 5 == 0) {
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return is_humble_number(n / 5);
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}
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if (n % 7 == 0) {
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return is_humble_number(n / 7);
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}
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return false;
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}
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/* Finds the even humble number larger than or equal the given number. */
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static int find_next_even_humble_number(int n)
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{
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if (n % 2 == 1) {
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n++;
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}
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while (true) {
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if (is_humble_number(n)) {
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return n;
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}
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n += 2;
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}
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return n;
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}
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int optimal_size_for_real_transform(int size)
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{
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/* FFTW is best at handling sizes of the form 2^a * 3^b * 5^c * 7^d * 11^e * 13^f, where e + f is
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* either 0 or 1, and the other exponents are arbitrary. And it is beneficial for the size to be
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* even for real transforms. To simplify computation, we ignore the 11 and 13 factors and find
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* the even humble number that is more then or equal the given size. See Section 4.3.3 Real-data
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* DFTs in the FFTW manual for more information. */
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return find_next_even_humble_number(size);
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}
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int2 optimal_size_for_real_transform(int2 size)
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{
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return int2(optimal_size_for_real_transform(size.x), optimal_size_for_real_transform(size.y));
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}
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/* See Section 5.2 Usage of Multi-threaded FFTW in the FFTW manual for more information. */
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[[maybe_unused]] static void tbb_parallel_loop_for_fftw(void *(*work)(char *),
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char *job_data,
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size_t element_size,
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int number_of_jobs,
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void * /*data*/)
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{
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threading::parallel_for(IndexRange(number_of_jobs), 1, [&](const IndexRange sub_range) {
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for (const int64_t i : sub_range) {
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work(job_data + element_size * i);
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}
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});
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}
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void initialize_float()
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{
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#if defined(WITH_FFTW3)
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fftwf_init_threads();
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fftwf_make_planner_thread_safe();
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fftwf_plan_with_nthreads(BLI_system_thread_count());
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fftwf_threads_set_callback(tbb_parallel_loop_for_fftw, nullptr);
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#endif
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}
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} // namespace blender::fftw
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