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