ceph/src/boost/libs/compute/include/boost/compute/algorithm/inner_product.hpp

   1 //---------------------------------------------------------------------------//
   2 // Copyright (c) 2013 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_ALGORITHM_INNER_PRODUCT_HPP
  12 #define BOOST_COMPUTE_ALGORITHM_INNER_PRODUCT_HPP
  13
  14 #include <boost/compute/system.hpp>
  15 #include <boost/compute/functional.hpp>
  16 #include <boost/compute/command_queue.hpp>
  17 #include <boost/compute/algorithm/accumulate.hpp>
  18 #include <boost/compute/container/vector.hpp>
  19 #include <boost/compute/iterator/transform_iterator.hpp>
  20 #include <boost/compute/iterator/zip_iterator.hpp>
  21 #include <boost/compute/functional/detail/unpack.hpp>
  22
  23 namespace boost {
  24 namespace compute {
  25
  26 /// Returns the inner product of the elements in the range
  27 /// [\p first1, \p last1) with the elements in the range beginning
  28 /// at \p first2.
  29 template<class InputIterator1, class InputIterator2, class T>
  30 inline T inner_product(InputIterator1 first1,
  31                        InputIterator1 last1,
  32                        InputIterator2 first2,
  33                        T init,
  34                        command_queue &queue = system::default_queue())
  35 {
  36     typedef typename std::iterator_traits<InputIterator1>::value_type input_type;
  37
  38     ptrdiff_t n = std::distance(first1, last1);
  39
  40     return ::boost::compute::accumulate(
  41         ::boost::compute::make_transform_iterator(
  42             ::boost::compute::make_zip_iterator(
  43                 boost::make_tuple(first1, first2)
  44             ),
  45             detail::unpack(multiplies<input_type>())
  46         ),
  47         ::boost::compute::make_transform_iterator(
  48             ::boost::compute::make_zip_iterator(
  49                 boost::make_tuple(last1, first2 + n)
  50             ),
  51             detail::unpack(multiplies<input_type>())
  52         ),
  53         init,
  54         queue
  55     );
  56 }
  57
  58 /// \overload
  59 template<class InputIterator1,
  60          class InputIterator2,
  61          class T,
  62          class BinaryAccumulateFunction,
  63          class BinaryTransformFunction>
  64 inline T inner_product(InputIterator1 first1,
  65                        InputIterator1 last1,
  66                        InputIterator2 first2,
  67                        T init,
  68                        BinaryAccumulateFunction accumulate_function,
  69                        BinaryTransformFunction transform_function,
  70                        command_queue &queue = system::default_queue())
  71 {
  72     typedef typename std::iterator_traits<InputIterator1>::value_type value_type;
  73
  74     size_t count = detail::iterator_range_size(first1, last1);
  75     vector<value_type> result(count, queue.get_context());
  76     transform(first1,
  77               last1,
  78               first2,
  79               result.begin(),
  80               transform_function,
  81               queue);
  82
  83     return ::boost::compute::accumulate(result.begin(),
  84                                         result.end(),
  85                                         init,
  86                                         accumulate_function,
  87                                         queue);
  88 }
  89
  90 } // end compute namespace
  91 } // end boost namespace
  92
  93 #endif // BOOST_COMPUTE_ALGORITHM_INNER_PRODUCT_HPP