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72 lines
2.4 KiB
72 lines
2.4 KiB
/* |
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* Copyright 2008-2012 NVIDIA Corporation |
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* |
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* Licensed under the Apache License, Version 2.0 (the "License"); |
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* you may not use this file except in compliance with the License. |
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* You may obtain a copy of the License at |
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* |
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* http://www.apache.org/licenses/LICENSE-2.0 |
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* |
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* Unless required by applicable law or agreed to in writing, software |
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* distributed under the License is distributed on an "AS IS" BASIS, |
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
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* See the License for the specific language governing permissions and |
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* limitations under the License. |
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*/ |
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#include <thrust/detail/config.h> |
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#include <thrust/iterator/iterator_traits.h> |
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#include <thrust/system/omp/detail/reduce.h> |
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#include <thrust/system/omp/detail/default_decomposition.h> |
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#include <thrust/system/omp/detail/reduce_intervals.h> |
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namespace thrust |
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{ |
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namespace system |
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{ |
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namespace omp |
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{ |
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namespace detail |
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{ |
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template<typename DerivedPolicy, |
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typename InputIterator, |
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typename OutputType, |
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typename BinaryFunction> |
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OutputType reduce(execution_policy<DerivedPolicy> &exec, |
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InputIterator first, |
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InputIterator last, |
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OutputType init, |
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BinaryFunction binary_op) |
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{ |
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typedef typename thrust::iterator_difference<InputIterator>::type difference_type; |
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const difference_type n = thrust::distance(first,last); |
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// determine first and second level decomposition |
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thrust::system::detail::internal::uniform_decomposition<difference_type> decomp1 = thrust::system::omp::detail::default_decomposition(n); |
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thrust::system::detail::internal::uniform_decomposition<difference_type> decomp2(decomp1.size() + 1, 1, 1); |
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// allocate storage for the initializer and partial sums |
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// XXX use select_system for Tag |
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thrust::detail::temporary_array<OutputType,DerivedPolicy> partial_sums(exec, decomp1.size() + 1); |
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// set first element of temp array to init |
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partial_sums[0] = init; |
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// accumulate partial sums (first level reduction) |
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thrust::system::omp::detail::reduce_intervals(exec, first, partial_sums.begin() + 1, binary_op, decomp1); |
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// reduce partial sums (second level reduction) |
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thrust::system::omp::detail::reduce_intervals(exec, partial_sums.begin(), partial_sums.begin(), binary_op, decomp2); |
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return partial_sums[0]; |
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} // end reduce() |
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} // end detail |
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} // end omp |
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} // end system |
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} // end thrust |
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