28 lines
773 B
Plaintext
28 lines
773 B
Plaintext
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#include <thrust/device_vector.h>
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#include <thrust/iterator/permutation_iterator.h>
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#include <thrust/reduce.h>
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#include <iostream>
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// this example fuses a gather operation with a reduction for
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// greater efficiency than separate gather() and reduce() calls
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int main()
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{
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// gather locations
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thrust::device_vector<int> map = {3, 1, 0, 5};
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// array to gather from
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thrust::device_vector<int> source = {10, 20, 30, 40, 50, 60};
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// fuse gather with reduction:
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// sum = source[map[0]] + source[map[1]] + ...
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int sum = thrust::reduce(thrust::make_permutation_iterator(source.begin(), map.begin()),
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thrust::make_permutation_iterator(source.begin(), map.end()));
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// print sum
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std::cout << "sum is " << sum << '\n';
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return 0;
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}
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