ceph/src/boost/libs/compute/example/mapped_view.cpp

   1 //---------------------------------------------------------------------------//
   2 // Copyright (c) 2013-2014 Kyle Lutz <kyle.r.lutz@gmail.com>
   3 //
   4 // Distributed under the Boost Software License, Version 1.0
   5 // See accompanying file LICENSE_1_0.txt or copy at
   6 // http://www.boost.org/LICENSE_1_0.txt
   7 //
   8 // See http://boostorg.github.com/compute for more information.
   9 //---------------------------------------------------------------------------//
  10
  11 #include <iostream>
  12 #include <vector>
  13
  14 #include <boost/compute/system.hpp>
  15 #include <boost/compute/algorithm/reduce.hpp>
  16 #include <boost/compute/container/mapped_view.hpp>
  17
  18 namespace compute = boost::compute;
  19
  20 // this example demonstrates how to use the mapped_view class to map
  21 // an array of numbers to device memory and use the reduce() algorithm
  22 // to calculate the sum.
  23 int main()
  24 {
  25     // get default device and setup context
  26     compute::device gpu = compute::system::default_device();
  27     compute::context context(gpu);
  28     compute::command_queue queue(context, gpu);
  29     std::cout << "device: " << gpu.name() << std::endl;
  30
  31     // create data on host
  32     int data[] = { 4, 2, 3, 7, 8, 9, 1, 6 };
  33
  34     // create mapped view on device
  35     compute::mapped_view<int> view(data, 8, context);
  36
  37     // use reduce() to calculate sum on the device
  38     int sum = 0;
  39     compute::reduce(view.begin(), view.end(), &sum, queue);
  40
  41     // print the sum on the host
  42     std::cout << "sum: " << sum << std::endl;
  43
  44     return 0;
  45 }