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Diffstat (limited to 'src/runtime/SchedulerUtils.cpp')
-rw-r--r-- | src/runtime/SchedulerUtils.cpp | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/src/runtime/SchedulerUtils.cpp b/src/runtime/SchedulerUtils.cpp new file mode 100644 index 0000000000..1c12e3ce58 --- /dev/null +++ b/src/runtime/SchedulerUtils.cpp @@ -0,0 +1,79 @@ +/* + * 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. + */ + +#include "arm_compute/core/Error.h" + +#include <cmath> + +namespace arm_compute +{ +#ifndef BARE_METAL +std::pair<unsigned, unsigned> split_2d(unsigned max_threads, std::size_t m, std::size_t n) +{ + /* + * We want the same ratio of threads in M & N to the ratio of m and n problem size + * + * Therefore: mt/nt == m/n where mt*nt == max_threads + * + * max_threads/nt = mt & (max_threads/nt) * (m/n) = nt + * nt^2 = max_threads * (m/n) + * nt = sqrt( max_threads * (m/n) ) + */ + //ratio of m to n in problem dimensions + double ratio = m / static_cast<double>(n); + + // nt = sqrt(max_threads * (m / n) ) + const unsigned adjusted = std::round( + std::sqrt(max_threads * ratio)); + + //find the nearest factor of max_threads + for(unsigned i = 0; i != adjusted; ++i) + { + //try down + const unsigned adj_down = adjusted - i; + if(max_threads % adj_down == 0) + { + return { adj_down, max_threads / adj_down }; + } + + //try up + const unsigned adj_up = adjusted + i; + if(max_threads % adj_up == 0) + { + return { adj_up, max_threads / adj_up }; + } + } + + //we didn't find anything so lets bail out with maxes biased to the largest dimension + if(m > n) + { + return { std::min<unsigned>(m, max_threads), 1 }; + } + else + { + return { 1, std::min<unsigned>(n, max_threads) }; + } +} +#endif /* #ifndef BARE_METAL */ +} // namespace arm_compute |