ceph/src/boost/libs/compute/include/boost/compute/detail/work_size.hpp

   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 #ifndef BOOST_COMPUTE_DETAIL_WORK_SIZE_HPP
  12 #define BOOST_COMPUTE_DETAIL_WORK_SIZE_HPP
  13
  14 #include <cmath>
  15
  16 namespace boost {
  17 namespace compute {
  18 namespace detail {
  19
  20 // Given a total number of values (count), a number of values to
  21 // process per thread (vtp), and a number of threads to execute per
  22 // block (tpb), this function returns the global work size to be
  23 // passed to clEnqueueNDRangeKernel() for a 1D algorithm.
  24 inline size_t calculate_work_size(size_t count, size_t vpt, size_t tpb)
  25 {
  26     size_t work_size = static_cast<size_t>(std::ceil(float(count) / vpt));
  27     if(work_size % tpb != 0){
  28         work_size += tpb - work_size % tpb;
  29     }
  30     return work_size;
  31 }
  32
  33 } // end detail namespace
  34 } // end compute namespace
  35 } // end boost namespace
  36
  37 #endif // BOOST_COMPUTE_DETAIL_WORK_SIZE_HPP