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lammps/lib/kokkos/example/cmake_build/cmake_example.cpp
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cmake_example.cpp
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/*
//@HEADER
// ************************************************************************
//
// Kokkos v. 2.0
// Copyright (2014) Sandia Corporation
//
// Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation,
// the U.S. Government retains certain rights in this software.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// 1. Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
//
// 3. Neither the name of the Corporation nor the names of the
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY SANDIA CORPORATION "AS IS" AND ANY
// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
// PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL SANDIA CORPORATION OR THE
// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// Questions? Contact H. Carter Edwards (hcedwar@sandia.gov)
//
// ************************************************************************
//@HEADER
*/
#include <Kokkos_Core.hpp>
#include <cstdio>
int main(int argc, char* argv[]) {
Kokkos::initialize(argc, argv);
Kokkos::DefaultExecutionSpace::print_configuration(std::cout);
if (argc < 2) {
fprintf(stderr, "Usage: %s [<kokkos_options>] <size>\n", argv[0]);
Kokkos::finalize();
exit(1);
}
const long n = strtol(argv[1], NULL, 10);
printf("Number of even integers from 0 to %ld\n", n - 1);
Kokkos::Timer timer;
timer.reset();
// Compute the number of even integers from 0 to n-1, in parallel.
long count = 0;
Kokkos::parallel_reduce(n, KOKKOS_LAMBDA (const long i, long& lcount) {
lcount += (i % 2) == 0;
}, count);
double count_time = timer.seconds();
printf(" Parallel: %ld %10.6f\n", count, count_time);
timer.reset();
// Compare to a sequential loop.
long seq_count = 0;
for (long i = 0; i < n; ++i) {
seq_count += (i % 2) == 0;
}
count_time = timer.seconds();
printf("Sequential: %ld %10.6f\n", seq_count, count_time);
Kokkos::finalize();
return (count == seq_count) ? 0 : -1;
}
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