algorithm/detail/search_all.hpp

0001 //---------------------------------------------------------------------------//
0002 // Copyright (c) 2014 Roshan <thisisroshansmail@gmail.com>
0003 //
0004 // Distributed under the Boost Software License, Version 1.0
0005 // See accompanying file LICENSE_1_0.txt or copy at
0006 // http://www.boost.org/LICENSE_1_0.txt
0007 //
0008 // See http://boostorg.github.com/compute for more information.
0009 //---------------------------------------------------------------------------//
0010
0011 #ifndef BOOST_COMPUTE_ALGORITHM_DETAIL_SEARCH_ALL_HPP
0012 #define BOOST_COMPUTE_ALGORITHM_DETAIL_SEARCH_ALL_HPP
0013
0014 #include <boost/compute/algorithm/copy.hpp>
0015 #include <boost/compute/container/vector.hpp>
0016 #include <boost/compute/detail/iterator_range_size.hpp>
0017 #include <boost/compute/detail/meta_kernel.hpp>
0018 #include <boost/compute/lambda.hpp>
0019 #include <boost/compute/system.hpp>
0020
0021 namespace boost {
0022 namespace compute {
0023 namespace detail {
0024
0025 ///
0026 /// \brief Search kernel class
0027 ///
0028 /// Subclass of meta_kernel which is capable of performing pattern matching
0029 ///
0030 template<class PatternIterator, class TextIterator, class OutputIterator>
0031 class search_kernel : public meta_kernel
0032 {
0033 public:
0034     search_kernel() : meta_kernel("search")
0035     {}
0036
0037     void set_range(PatternIterator p_first,
0038                    PatternIterator p_last,
0039                    TextIterator t_first,
0040                    TextIterator t_last,
0041                    OutputIterator result)
0042     {
0043         m_p_count = iterator_range_size(p_first, p_last);
0044         m_p_count_arg = add_arg<uint_>("p_count");
0045
0046         m_count = iterator_range_size(t_first, t_last);
0047         m_count = m_count + 1 - m_p_count;
0048
0049         *this <<
0050             "uint i = get_global_id(0);\n" <<
0051             "const uint i1 = i;\n" <<
0052             "uint j;\n" <<
0053             "for(j = 0; j<p_count; j++,i++)\n" <<
0054             "{\n" <<
0055             "   if(" << p_first[expr<uint_>("j")] << " != " <<
0056                     t_first[expr<uint_>("i")] << ")\n" <<
0057             "       j = p_count + 1;\n" <<
0058             "}\n" <<
0059             "if(j == p_count)\n" <<
0060             result[expr<uint_>("i1")] << " = 1;\n" <<
0061             "else\n" <<
0062             result[expr<uint_>("i1")] << " = 0;\n";
0063     }
0064
0065     event exec(command_queue &queue)
0066     {
0067         if(m_count == 0) {
0068             return event();
0069         }
0070
0071         set_arg(m_p_count_arg, uint_(m_p_count));
0072
0073         return exec_1d(queue, 0, m_count);
0074     }
0075
0076 private:
0077     size_t m_p_count;
0078     size_t m_p_count_arg;
0079     size_t m_count;
0080 };
0081
0082 } //end detail namespace
0083 } //end compute namespace
0084 } //end boost namespace
0085
0086 #endif // BOOST_COMPUTE_ALGORITHM_DETAIL_SEARCH_ALL_HPP