/Src/Dependencies/Boost/libs/phoenix/example/parallel_for.cpp
C++ | 239 lines | 201 code | 30 blank | 8 comment | 5 complexity | c84b62e3308bb5e6641827ad0c1ba94f MD5 | raw file
1 2#include <boost/phoenix.hpp> 3 4struct omp_for_eval 5{ 6 typedef void result_type; 7 8 template <typename Init, typename Cond, typename Step, typename Do, typename Context> 9 result_type 10 operator()( 11 Init const& init 12 , Cond const& cond 13 , Step const& step 14 , Do const& do_ 15 , Context & ctx 16 ) const 17 { 18#pragma omp parallel 19 for( 20 boost::phoenix::eval(init, ctx); 21 boost::phoenix::eval(cond, ctx); 22 boost::phoenix::eval(step, ctx) 23 ) 24 { 25 boost::phoenix::eval(do_, ctx); 26 } 27 } 28}; 29 30 31//////////////////////////////////////////////////////////////////////////////// 32// Define new custom expression 33BOOST_PHOENIX_DEFINE_EXPRESSION( 34 (omp_for) 35 , (boost::phoenix::meta_grammar) // Cond 36 (boost::phoenix::meta_grammar) // Init 37 (boost::phoenix::meta_grammar) // Step 38 (boost::phoenix::meta_grammar) // Do 39) 40 41namespace boost { namespace phoenix 42{ 43 template <> 44 struct default_actions::when< ::rule::omp_for> 45 : boost::phoenix::call< ::omp_for_eval> 46 {}; 47}} 48 49template <typename Init, typename Cond, typename Step> 50struct omp_for_gen 51{ 52 omp_for_gen(Init const& init, Cond const& cond, Step const& step) 53 : init(init), cond(cond), step(step) {} 54 55 template <typename Do> 56 typename result_of::make_omp_for<Init, Cond, Step, Do>::type const 57 operator[](Do const& do_) const 58 { 59 return make_omp_for(init, cond, step, do_); 60 } 61 62 Init init; 63 Cond cond; 64 Step step; 65}; 66 67template <typename Init, typename Cond, typename Step> 68inline 69omp_for_gen<Init, Cond, Step> const 70omp_for(Init const& init, Cond const& cond, Step const& step) 71{ 72 return omp_for_gen<Init, Cond, Step>(init, cond, step); 73} 74//////////////////////////////////////////////////////////////////////////////// 75 76 77//////////////////////////////////////////////////////////////////////////////// 78// Define new evaluation scheme 79 80struct parallel_actions 81{ 82 template <typename Rule> 83 struct when 84 : boost::phoenix::default_actions::when<Rule> 85 {}; 86}; 87 88template <> 89struct parallel_actions::when<boost::phoenix::rule::for_> 90 : boost::phoenix::call<omp_for_eval> 91{}; 92 93// Doing the same as actor<Expr>::operator 94template <typename Expr, typename A0, typename A1, typename A2> 95typename boost::phoenix::result_of::eval< 96 Expr const & 97 , typename boost::phoenix::result_of::make_context< 98 typename boost::phoenix::result_of::make_env< 99 Expr const * 100 , A0 & 101 , A1 & 102 , A2 & 103 >::type 104 , parallel_actions 105 >::type 106>::type 107parallel_eval(Expr & expr, A0 & a0, A1 & a1, A2 & a2) 108{ 109 Expr const * this_ = boost::addressof(expr); 110 return 111 boost::phoenix::eval( 112 expr 113 , boost::phoenix::make_context( 114 boost::phoenix::make_env(this_, a0, a1, a2) 115 , parallel_actions() 116 ) 117 ); 118} 119 120// changing evaluation mechanism on the fly 121BOOST_PHOENIX_DEFINE_EXPRESSION( 122 (parallel) 123 , (boost::phoenix::meta_grammar) 124) 125 126namespace boost { namespace phoenix 127{ 128 template <> 129 struct default_actions::when< ::rule::parallel> 130 : proto::call< 131 evaluator( 132 proto::_child0 133 , functional::make_context( 134 _env 135 , parallel_actions() 136 ) 137 , unused()//mpl::void_() 138 ) 139 > 140 {}; 141}} 142 143template <typename Expr> 144typename result_of::make_parallel<Expr>::type 145parallel(Expr const & expr) 146{ 147 return make_parallel(expr); 148} 149//////////////////////////////////////////////////////////////////////////////// 150 151 152#include <vector> 153#include <iostream> 154 155int main() 156{ 157 using boost::phoenix::arg_names::_1; 158 using boost::phoenix::arg_names::_2; 159 using boost::phoenix::arg_names::_3; 160 using boost::phoenix::local_names::_a; 161 using boost::phoenix::local_names::_b; 162 using boost::phoenix::local_names::_c; 163 using boost::phoenix::let; 164 using boost::phoenix::bind; 165 using boost::phoenix::lambda; 166 using boost::phoenix::nothing; 167 168 const int NUM = 1; 169 170 { 171 std::vector<int> a(NUM, 1); 172 std::vector<int> b(NUM, 2); 173 std::vector<int> c(NUM, 0); 174 175 ( 176 let(_a = begin(_1), _b = begin(_2), _c = begin(_3)) 177 [ 178 for_(nothing, _a != end(_1), (++_a, ++_b, ++_c)) 179 [ 180 *_c = *_a + *_b 181 ] 182 ] 183 , std::cout << accumulate(_3, 0) << "\n" 184 )(a, b, c); 185 } 186 187 { 188 std::vector<int> a(NUM, 1); 189 std::vector<int> b(NUM, 2); 190 std::vector<int> c(NUM, 0); 191 192 ( 193 let(_a = begin(_1), _b = begin(_2), _c = begin(_3)) 194 [ 195 omp_for(nothing, _a != end(_1), (++_a, ++_b, ++_c)) 196 [ 197 *_c = *_a + *_b 198 ] 199 , std::cout << accumulate(_3, 0) << "\n" 200 ] 201 )(a, b, c); 202 } 203 204 { 205 std::vector<int> a(NUM, 1); 206 std::vector<int> b(NUM, 2); 207 std::vector<int> c(NUM, 0); 208 209 parallel_eval( 210 let(_a = begin(_1), _b = begin(_2), _c = begin(_3)) 211 [ 212 for_(nothing, _a != end(_1), (++_a, ++_b, ++_c)) 213 [ 214 *_c = *_a + *_b 215 ] 216 , std::cout << accumulate(_3, 0) << "\n" 217 ] 218 , a, b, c); 219 } 220 221 { 222 std::vector<int> a(NUM, 1); 223 std::vector<int> b(NUM, 2); 224 std::vector<int> c(NUM, 0); 225 226 ( 227 let(_a = begin(_1), _b = begin(_2), _c = begin(_3)) 228 [ 229 parallel( 230 for_(nothing, _a != end(_1), (++_a, ++_b, ++_c)) 231 [ 232 *_c = *_a + *_b 233 ] 234 ) 235 ] 236 , std::cout << accumulate(_3, 0) << "\n" 237 )(a, b, c); 238 } 239}