1 | // |
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2 | // Cforall Version 1.0.0 Copyright (C) 2015 University of Waterloo |
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3 | // |
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4 | // The contents of this file are covered under the licence agreement in the |
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5 | // file "LICENCE" distributed with Cforall. |
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6 | // |
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7 | // SpecCost.cc -- |
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8 | // |
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9 | // Author : Aaron B. Moss |
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10 | // Created On : Tue Oct 02 15:50:00 2018 |
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11 | // Last Modified By : Andrew Beach |
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12 | // Last Modified On : Wed Jul 3 11:07:00 2019 |
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13 | // Update Count : 3 |
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14 | // |
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15 | |
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16 | #include <cassert> |
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17 | #include <limits> |
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18 | #include <list> |
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19 | #include <type_traits> |
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20 | |
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21 | #include "AST/Pass.hpp" |
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22 | #include "AST/Type.hpp" |
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23 | #include "Common/PassVisitor.h" |
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24 | #include "SynTree/Declaration.h" |
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25 | #include "SynTree/Expression.h" |
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26 | #include "SynTree/Type.h" |
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27 | |
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28 | namespace ResolvExpr { |
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29 | |
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30 | /// Counts specializations in a type |
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31 | class CountSpecs : public WithShortCircuiting, public WithVisitorRef<CountSpecs> { |
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32 | int count = -1; ///< specialization count (-1 for none) |
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33 | |
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34 | public: |
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35 | int get_count() const { return count >= 0 ? count : 0; } |
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36 | |
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37 | // mark specialization of base type |
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38 | void postvisit(PointerType*) { if ( count >= 0 ) ++count; } |
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39 | |
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40 | // mark specialization of base type |
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41 | void postvisit(ArrayType*) { if ( count >= 0 ) ++count; } |
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42 | |
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43 | // mark specialization of base type |
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44 | void postvisit(ReferenceType*) { if ( count >= 0 ) ++count; } |
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45 | |
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46 | private: |
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47 | // takes minimum non-negative count over parameter/return list |
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48 | void takeminover( int& mincount, std::list<DeclarationWithType*>& dwts ) { |
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49 | for ( DeclarationWithType* dwt : dwts ) { |
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50 | count = -1; |
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51 | maybeAccept( dwt->get_type(), *visitor ); |
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52 | if ( count != -1 && count < mincount ) mincount = count; |
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53 | } |
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54 | } |
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55 | |
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56 | public: |
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57 | // take minimal specialization value over ->returnVals and ->parameters |
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58 | void previsit(FunctionType* fty) { |
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59 | int mincount = std::numeric_limits<int>::max(); |
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60 | takeminover( mincount, fty->parameters ); |
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61 | takeminover( mincount, fty->returnVals ); |
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62 | // add another level to mincount if set |
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63 | count = mincount < std::numeric_limits<int>::max() ? mincount + 1 : -1; |
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64 | // already visited children |
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65 | visit_children = false; |
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66 | } |
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67 | |
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68 | private: |
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69 | // returns minimum non-negative count + 1 over type parameters (-1 if none such) |
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70 | int minover( std::list<Expression*>& parms ) { |
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71 | int mincount = std::numeric_limits<int>::max(); |
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72 | for ( Expression* parm : parms ) { |
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73 | count = -1; |
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74 | maybeAccept( parm->result, *visitor ); |
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75 | if ( count != -1 && count < mincount ) mincount = count; |
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76 | } |
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77 | return mincount < std::numeric_limits<int>::max() ? mincount + 1 : -1; |
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78 | } |
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79 | |
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80 | public: |
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81 | // look for polymorphic parameters |
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82 | void previsit(StructInstType* sty) { |
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83 | count = minover( sty->parameters ); |
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84 | visit_children = false; |
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85 | } |
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86 | |
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87 | // look for polymorphic parameters |
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88 | void previsit(UnionInstType* uty) { |
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89 | count = minover( uty->parameters ); |
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90 | visit_children = false; |
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91 | } |
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92 | |
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93 | // note polymorphic type (which may be specialized) |
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94 | // xxx - maybe account for open/closed type variables |
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95 | void postvisit(TypeInstType*) { count = 0; } |
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96 | |
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97 | // take minimal specialization over elements |
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98 | // xxx - maybe don't increment, tuple flattening doesn't necessarily specialize |
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99 | void previsit(TupleType* tty) { |
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100 | int mincount = std::numeric_limits<int>::max(); |
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101 | for ( Type* ty : tty->types ) { |
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102 | count = -1; |
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103 | maybeAccept( ty, *visitor ); |
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104 | if ( count != -1 && count < mincount ) mincount = count; |
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105 | } |
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106 | count = mincount < std::numeric_limits<int>::max() ? mincount + 1 : -1; |
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107 | visit_children = false; |
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108 | } |
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109 | }; |
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110 | |
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111 | /// Returns the (negated) specialization cost for a given type |
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112 | int specCost( Type* ty ) { |
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113 | PassVisitor<CountSpecs> counter; |
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114 | maybeAccept( ty, *counter.pass.visitor ); |
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115 | return counter.pass.get_count(); |
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116 | } |
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117 | |
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118 | namespace { |
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119 | /// The specialization counter inner class. |
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120 | class SpecCounter : public ast::WithShortCircuiting, public ast::WithVisitorRef<SpecCounter> { |
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121 | int count = -1; ///< specialization count (-1 for none) |
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122 | |
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123 | // Converts the max value to -1 (none), otherwise increments the value. |
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124 | static int toNoneOrInc( int value ) { |
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125 | assert( 0 <= value ); |
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126 | return value < std::numeric_limits<int>::max() ? value + 1 : -1; |
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127 | } |
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128 | |
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129 | template<typename T> using MapperT = |
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130 | typename std::add_pointer<ast::Type const *(typename T::value_type const &)>::type; |
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131 | |
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132 | #warning Should use a standard maybe_accept |
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133 | void maybe_accept( ast::Type const * type ) { |
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134 | if ( type ) { |
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135 | auto node = type->accept( *visitor ); |
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136 | assert( node == nullptr || node == type ); |
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137 | } |
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138 | } |
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139 | |
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140 | // Update the minimum to the new lowest non-none value. |
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141 | template<typename T> |
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142 | void updateMinimumPresent( int & minimum, const T & list, MapperT<T> mapper ) { |
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143 | for ( const auto & node : list ) { |
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144 | count = -1; |
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145 | maybe_accept( mapper( node ) ); |
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146 | if ( count != -1 && count < minimum ) minimum = count; |
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147 | } |
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148 | } |
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149 | |
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150 | // Returns minimum non-negative count + 1 over type parameters (-1 if none such). |
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151 | template<typename T> |
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152 | int minimumPresent( const T & list, MapperT<T> mapper ) { |
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153 | int minCount = std::numeric_limits<int>::max(); |
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154 | updateMinimumPresent( minCount, list, mapper ); |
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155 | return toNoneOrInc( minCount ); |
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156 | } |
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157 | |
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158 | // The three mappers: |
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159 | static const ast::Type * decl_type( const ast::ptr< ast::DeclWithType > & decl ) { |
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160 | return decl->get_type(); |
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161 | } |
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162 | static const ast::Type * expr_result( const ast::ptr< ast::Expr > & expr ) { |
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163 | return expr->result; |
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164 | } |
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165 | static const ast::Type * type_deref( const ast::ptr< ast::Type > & type ) { |
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166 | return type.get(); |
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167 | } |
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168 | |
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169 | public: |
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170 | int get_count() const { return 0 <= count ? count : 0; } |
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171 | |
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172 | // Mark specialization of base type. |
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173 | void postvisit( const ast::PointerType * ) { if ( count >= 0 ) ++count; } |
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174 | void postvisit( const ast::ArrayType * ) { if ( count >= 0 ) ++count; } |
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175 | void postvisit( const ast::ReferenceType * ) { if ( count >= 0 ) ++count; } |
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176 | |
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177 | // Use the minimal specialization value over returns and params. |
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178 | void previsit( const ast::FunctionType * fty ) { |
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179 | int minCount = std::numeric_limits<int>::max(); |
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180 | updateMinimumPresent( minCount, fty->params, type_deref ); |
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181 | updateMinimumPresent( minCount, fty->returns, type_deref ); |
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182 | // Add another level to minCount if set. |
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183 | count = toNoneOrInc( minCount ); |
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184 | // We have already visited children. |
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185 | visit_children = false; |
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186 | } |
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187 | |
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188 | // Look for polymorphic parameters. |
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189 | void previsit( const ast::StructInstType * sty ) { |
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190 | count = minimumPresent( sty->params, expr_result ); |
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191 | visit_children = false; |
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192 | } |
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193 | |
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194 | // Look for polymorphic parameters. |
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195 | void previsit( const ast::UnionInstType * uty ) { |
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196 | count = minimumPresent( uty->params, expr_result ); |
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197 | visit_children = false; |
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198 | } |
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199 | |
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200 | // Note polymorphic type (which may be specialized). |
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201 | // xxx - maybe account for open/closed type variables |
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202 | void postvisit( const ast::TypeInstType * ) { count = 0; } |
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203 | |
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204 | // Use the minimal specialization over elements. |
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205 | // xxx - maybe don't increment, tuple flattening doesn't necessarily specialize |
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206 | void previsit( const ast::TupleType * tty ) { |
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207 | count = minimumPresent( tty->types, type_deref ); |
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208 | visit_children = false; |
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209 | } |
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210 | }; |
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211 | |
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212 | } // namespace |
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213 | |
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214 | int specCost( const ast::Type * type ) { |
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215 | if ( nullptr == type ) { |
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216 | return 0; |
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217 | } |
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218 | ast::Pass<SpecCounter> counter; |
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219 | type->accept( counter ); |
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220 | return counter.core.get_count(); |
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221 | } |
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222 | |
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223 | } // namespace ResolvExpr |
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224 | |
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225 | // Local Variables: // |
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226 | // tab-width: 4 // |
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227 | // mode: c++ // |
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228 | // compile-command: "make install" // |
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229 | // End: // |
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