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			3.1 KiB
		
	
	
	
		
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			100 lines
		
	
	
		
			3.1 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
|   | //---------------------------------------------------------------------------// | ||
|  | // Copyright (c) 2013 Kyle Lutz <kyle.r.lutz@gmail.com> | ||
|  | // | ||
|  | // Distributed under the Boost Software License, Version 1.0 | ||
|  | // See accompanying file LICENSE_1_0.txt or copy at | ||
|  | // http://www.boost.org/LICENSE_1_0.txt | ||
|  | // | ||
|  | // See http://boostorg.github.com/compute for more information. | ||
|  | //---------------------------------------------------------------------------// | ||
|  | 
 | ||
|  | #ifndef BOOST_COMPUTE_ALGORITHM_SCATTER_HPP | ||
|  | #define BOOST_COMPUTE_ALGORITHM_SCATTER_HPP | ||
|  | 
 | ||
|  | #include <boost/algorithm/string/replace.hpp> | ||
|  | 
 | ||
|  | #include <boost/compute/system.hpp> | ||
|  | #include <boost/compute/exception.hpp> | ||
|  | #include <boost/compute/command_queue.hpp> | ||
|  | #include <boost/compute/iterator/buffer_iterator.hpp> | ||
|  | #include <boost/compute/type_traits/type_name.hpp> | ||
|  | #include <boost/compute/detail/iterator_range_size.hpp> | ||
|  | #include <boost/compute/detail/meta_kernel.hpp> | ||
|  | 
 | ||
|  | namespace boost { | ||
|  | namespace compute { | ||
|  | namespace detail { | ||
|  | 
 | ||
|  | template<class InputIterator, class MapIterator, class OutputIterator> | ||
|  | class scatter_kernel : meta_kernel | ||
|  | { | ||
|  | public: | ||
|  |     scatter_kernel() : meta_kernel("scatter") | ||
|  |     {} | ||
|  | 
 | ||
|  |     void set_range(InputIterator first, | ||
|  |                    InputIterator last, | ||
|  |                    MapIterator map, | ||
|  |                    OutputIterator result) | ||
|  |     { | ||
|  |         m_count = iterator_range_size(first, last); | ||
|  |         m_input_offset = first.get_index(); | ||
|  |         m_output_offset = result.get_index(); | ||
|  | 
 | ||
|  |         m_input_offset_arg = add_arg<uint_>("input_offset"); | ||
|  |         m_output_offset_arg = add_arg<uint_>("output_offset"); | ||
|  | 
 | ||
|  |         *this << | ||
|  |             "const uint i = get_global_id(0);\n" << | ||
|  |             "uint i1 = " << map[expr<uint_>("i")] <<  | ||
|  |                 " + output_offset;\n" << | ||
|  |             "uint i2 = i + input_offset;\n" << | ||
|  |             result[expr<uint_>("i1")] << "=" <<  | ||
|  |                 first[expr<uint_>("i2")] << ";\n"; | ||
|  |     } | ||
|  | 
 | ||
|  |     event exec(command_queue &queue) | ||
|  |     { | ||
|  |         if(m_count == 0) { | ||
|  |             return event(); | ||
|  |         } | ||
|  | 
 | ||
|  |         set_arg(m_input_offset_arg, uint_(m_input_offset)); | ||
|  |         set_arg(m_output_offset_arg, uint_(m_output_offset)); | ||
|  | 
 | ||
|  |         return exec_1d(queue, 0, m_count); | ||
|  |     } | ||
|  | 
 | ||
|  | private: | ||
|  |     size_t m_count; | ||
|  |     size_t m_input_offset;     | ||
|  |     size_t m_input_offset_arg;     | ||
|  |     size_t m_output_offset;     | ||
|  |     size_t m_output_offset_arg;     | ||
|  | }; | ||
|  | 
 | ||
|  | } // end detail namespace | ||
|  | 
 | ||
|  | /// Copies the elements from the range [\p first, \p last) to the range | ||
|  | /// beginning at \p result using the output indices from the range beginning | ||
|  | /// at \p map. | ||
|  | /// | ||
|  | /// \see gather() | ||
|  | template<class InputIterator, class MapIterator, class OutputIterator> | ||
|  | inline void scatter(InputIterator first, | ||
|  |                     InputIterator last, | ||
|  |                     MapIterator map, | ||
|  |                     OutputIterator result, | ||
|  |                     command_queue &queue = system::default_queue()) | ||
|  | { | ||
|  |     detail::scatter_kernel<InputIterator, MapIterator, OutputIterator> kernel; | ||
|  |      | ||
|  |     kernel.set_range(first, last, map, result); | ||
|  |     kernel.exec(queue); | ||
|  | } | ||
|  | 
 | ||
|  | } // end compute namespace | ||
|  | } // end boost namespace | ||
|  | 
 | ||
|  | #endif // BOOST_COMPUTE_ALGORITHM_SCATTER_HPP |