75 lines
		
	
	
		
			2.3 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
			
		
		
	
	
			75 lines
		
	
	
		
			2.3 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_REVERSE_HPP
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| #define BOOST_COMPUTE_ALGORITHM_REVERSE_HPP
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| 
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| #include <boost/compute/system.hpp>
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| #include <boost/compute/command_queue.hpp>
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| #include <boost/compute/detail/meta_kernel.hpp>
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| #include <boost/compute/detail/iterator_range_size.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 Iterator>
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| struct reverse_kernel : public meta_kernel
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| {
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|     reverse_kernel(Iterator first, Iterator last)
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|         : meta_kernel("reverse")
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|     {
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|         typedef typename std::iterator_traits<Iterator>::value_type value_type;
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| 
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|         // store size of the range
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|         m_size = detail::iterator_range_size(first, last);
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|         add_set_arg<const cl_uint>("size", static_cast<const cl_uint>(m_size));
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| 
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|         *this <<
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|             decl<cl_uint>("i") << " = get_global_id(0);\n" <<
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|             decl<cl_uint>("j") << " = size - get_global_id(0) - 1;\n" <<
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|             decl<value_type>("tmp") << "=" << first[var<cl_uint>("i")] << ";\n" <<
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|             first[var<cl_uint>("i")] << "=" << first[var<cl_uint>("j")] << ";\n" <<
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|             first[var<cl_uint>("j")] << "= tmp;\n";
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|     }
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| 
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|     void exec(command_queue &queue)
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|     {
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|         exec_1d(queue, 0, m_size / 2);
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|     }
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| 
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|     size_t m_size;
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| };
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| 
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| } // end detail namespace
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| 
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| /// Reverses the elements in the range [\p first, \p last).
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| ///
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| /// \see reverse_copy()
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| template<class Iterator>
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| inline void reverse(Iterator first,
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|                     Iterator last,
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|                     command_queue &queue = system::default_queue())
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| {
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|     size_t count = detail::iterator_range_size(first, last);
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|     if(count < 2){
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|         return;
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|     }
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| 
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|     detail::reverse_kernel<Iterator> kernel(first, last);
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| 
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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_REVERSE_HPP
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