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 | // Specialize.cc -- |
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8 | // |
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9 | // Author : Richard C. Bilson |
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10 | // Created On : Mon May 18 07:44:20 2015 |
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11 | // Last Modified By : Rob Schluntz |
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12 | // Last Modified On : Thu Apr 28 15:17:45 2016 |
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13 | // Update Count : 24 |
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14 | // |
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15 | |
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16 | #include <cassert> |
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17 | |
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18 | #include "Specialize.h" |
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19 | #include "GenPoly.h" |
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20 | #include "PolyMutator.h" |
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21 | |
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22 | #include "Parser/ParseNode.h" |
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23 | |
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24 | #include "SynTree/Expression.h" |
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25 | #include "SynTree/Statement.h" |
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26 | #include "SynTree/Type.h" |
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27 | #include "SynTree/Attribute.h" |
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28 | #include "SynTree/TypeSubstitution.h" |
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29 | #include "SynTree/Mutator.h" |
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30 | #include "ResolvExpr/FindOpenVars.h" |
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31 | #include "Common/UniqueName.h" |
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32 | #include "Common/utility.h" |
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33 | #include "InitTweak/InitTweak.h" |
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34 | |
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35 | namespace GenPoly { |
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36 | class Specializer; |
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37 | class Specialize final : public PolyMutator { |
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38 | friend class Specializer; |
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39 | public: |
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40 | using PolyMutator::mutate; |
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41 | virtual Expression * mutate( ApplicationExpr *applicationExpr ) override; |
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42 | virtual Expression * mutate( AddressExpr *castExpr ) override; |
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43 | virtual Expression * mutate( CastExpr *castExpr ) override; |
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44 | // virtual Expression * mutate( LogicalExpr *logicalExpr ); |
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45 | // virtual Expression * mutate( ConditionalExpr *conditionalExpr ); |
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46 | // virtual Expression * mutate( CommaExpr *commaExpr ); |
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47 | |
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48 | Specializer * specializer = nullptr; |
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49 | void handleExplicitParams( ApplicationExpr *appExpr ); |
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50 | }; |
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51 | |
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52 | class Specializer { |
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53 | public: |
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54 | Specializer( Specialize & spec ) : spec( spec ), env( spec.env ), stmtsToAdd( spec.stmtsToAdd ) {} |
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55 | virtual bool needsSpecialization( Type * formalType, Type * actualType, TypeSubstitution * env ) = 0; |
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56 | virtual Expression *createThunkFunction( FunctionType *funType, Expression *actual, InferredParams *inferParams ) = 0; |
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57 | virtual Expression *doSpecialization( Type *formalType, Expression *actual, InferredParams *inferParams = 0 ); |
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58 | |
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59 | protected: |
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60 | Specialize & spec; |
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61 | std::string paramPrefix = "_p"; |
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62 | TypeSubstitution *& env; |
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63 | std::list< Statement * > & stmtsToAdd; |
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64 | }; |
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65 | |
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66 | // for normal polymorphic -> monomorphic function conversion |
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67 | class PolySpecializer : public Specializer { |
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68 | public: |
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69 | PolySpecializer( Specialize & spec ) : Specializer( spec ) {} |
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70 | virtual bool needsSpecialization( Type * formalType, Type * actualType, TypeSubstitution * env ) override; |
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71 | virtual Expression *createThunkFunction( FunctionType *funType, Expression *actual, InferredParams *inferParams ) override; |
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72 | }; |
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73 | |
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74 | // // for tuple -> non-tuple function conversion |
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75 | class TupleSpecializer : public Specializer { |
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76 | public: |
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77 | TupleSpecializer( Specialize & spec ) : Specializer( spec ) {} |
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78 | virtual bool needsSpecialization( Type * formalType, Type * actualType, TypeSubstitution * env ) override; |
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79 | virtual Expression *createThunkFunction( FunctionType *funType, Expression *actual, InferredParams *inferParams ) override; |
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80 | }; |
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81 | |
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82 | /// Looks up open variables in actual type, returning true if any of them are bound in the environment or formal type. |
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83 | bool PolySpecializer::needsSpecialization( Type *formalType, Type *actualType, TypeSubstitution *env ) { |
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84 | if ( env ) { |
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85 | using namespace ResolvExpr; |
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86 | OpenVarSet openVars, closedVars; |
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87 | AssertionSet need, have; |
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88 | findOpenVars( formalType, openVars, closedVars, need, have, false ); |
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89 | findOpenVars( actualType, openVars, closedVars, need, have, true ); |
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90 | for ( OpenVarSet::const_iterator openVar = openVars.begin(); openVar != openVars.end(); ++openVar ) { |
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91 | Type *boundType = env->lookup( openVar->first ); |
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92 | if ( ! boundType ) continue; |
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93 | if ( TypeInstType *typeInst = dynamic_cast< TypeInstType* >( boundType ) ) { |
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94 | if ( closedVars.find( typeInst->get_name() ) == closedVars.end() ) { |
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95 | return true; |
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96 | } // if |
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97 | } else { |
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98 | return true; |
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99 | } // if |
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100 | } // for |
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101 | return false; |
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102 | } else { |
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103 | return false; |
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104 | } // if |
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105 | } |
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106 | |
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107 | /// Generates a thunk that calls `actual` with type `funType` and returns its address |
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108 | Expression * PolySpecializer::createThunkFunction( FunctionType *funType, Expression *actual, InferredParams *inferParams ) { |
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109 | static UniqueName thunkNamer( "_thunk" ); |
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110 | |
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111 | FunctionType *newType = funType->clone(); |
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112 | if ( env ) { |
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113 | TypeSubstitution newEnv( *env ); |
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114 | // it is important to replace only occurrences of type variables that occur free in the |
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115 | // thunk's type |
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116 | newEnv.applyFree( newType ); |
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117 | } // if |
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118 | // create new thunk with same signature as formal type (C linkage, empty body) |
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119 | FunctionDecl *thunkFunc = new FunctionDecl( thunkNamer.newName(), DeclarationNode::NoStorageClass, LinkageSpec::C, newType, new CompoundStmt( noLabels ), false, false ); |
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120 | thunkFunc->fixUniqueId(); |
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121 | |
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122 | // thunks may be generated and not used - silence warning with attribute |
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123 | thunkFunc->get_attributes().push_back( new Attribute( "unused" ) ); |
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124 | |
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125 | // thread thunk parameters into call to actual function, naming thunk parameters as we go |
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126 | UniqueName paramNamer( paramPrefix ); |
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127 | ApplicationExpr *appExpr = new ApplicationExpr( actual ); |
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128 | for ( std::list< DeclarationWithType* >::iterator param = thunkFunc->get_functionType()->get_parameters().begin(); param != thunkFunc->get_functionType()->get_parameters().end(); ++param ) { |
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129 | (*param )->set_name( paramNamer.newName() ); |
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130 | appExpr->get_args().push_back( new VariableExpr( *param ) ); |
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131 | } // for |
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132 | appExpr->set_env( maybeClone( env ) ); |
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133 | if ( inferParams ) { |
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134 | appExpr->get_inferParams() = *inferParams; |
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135 | } // if |
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136 | |
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137 | // handle any specializations that may still be present |
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138 | std::string oldParamPrefix = paramPrefix; |
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139 | paramPrefix += "p"; |
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140 | // save stmtsToAdd in oldStmts |
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141 | std::list< Statement* > oldStmts; |
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142 | oldStmts.splice( oldStmts.end(), stmtsToAdd ); |
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143 | spec.handleExplicitParams( appExpr ); |
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144 | paramPrefix = oldParamPrefix; |
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145 | // write any statements added for recursive specializations into the thunk body |
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146 | thunkFunc->get_statements()->get_kids().splice( thunkFunc->get_statements()->get_kids().end(), stmtsToAdd ); |
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147 | // restore oldStmts into stmtsToAdd |
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148 | stmtsToAdd.splice( stmtsToAdd.end(), oldStmts ); |
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149 | |
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150 | // add return (or valueless expression) to the thunk |
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151 | Statement *appStmt; |
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152 | if ( funType->get_returnVals().empty() ) { |
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153 | appStmt = new ExprStmt( noLabels, appExpr ); |
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154 | } else { |
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155 | appStmt = new ReturnStmt( noLabels, appExpr ); |
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156 | } // if |
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157 | thunkFunc->get_statements()->get_kids().push_back( appStmt ); |
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158 | |
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159 | // add thunk definition to queue of statements to add |
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160 | stmtsToAdd.push_back( new DeclStmt( noLabels, thunkFunc ) ); |
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161 | // return address of thunk function as replacement expression |
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162 | return new AddressExpr( new VariableExpr( thunkFunc ) ); |
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163 | } |
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164 | |
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165 | Expression * Specializer::doSpecialization( Type *formalType, Expression *actual, InferredParams *inferParams ) { |
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166 | assertf( actual->has_result(), "attempting to specialize an untyped expression" ); |
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167 | if ( needsSpecialization( formalType, actual->get_result(), env ) ) { |
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168 | FunctionType *funType; |
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169 | if ( ( funType = getFunctionType( formalType ) ) ) { |
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170 | ApplicationExpr *appExpr; |
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171 | VariableExpr *varExpr; |
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172 | if ( ( appExpr = dynamic_cast<ApplicationExpr*>( actual ) ) ) { |
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173 | return createThunkFunction( funType, appExpr->get_function(), inferParams ); |
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174 | } else if ( ( varExpr = dynamic_cast<VariableExpr*>( actual ) ) ) { |
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175 | return createThunkFunction( funType, varExpr, inferParams ); |
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176 | } else { |
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177 | // This likely won't work, as anything that could build an ApplicationExpr probably hit one of the previous two branches |
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178 | return createThunkFunction( funType, actual, inferParams ); |
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179 | } |
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180 | } else { |
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181 | return actual; |
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182 | } // if |
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183 | } else { |
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184 | return actual; |
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185 | } // if |
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186 | } |
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187 | |
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188 | bool TupleSpecializer::needsSpecialization( Type *formalType, Type *actualType, TypeSubstitution *env ) { |
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189 | // std::cerr << "asking if type needs tuple spec: " << formalType << std::endl; |
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190 | if ( FunctionType * ftype = getFunctionType( formalType ) ) { |
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191 | return ftype->isTtype(); |
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192 | } |
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193 | return false; |
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194 | } |
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195 | |
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196 | template< typename Iterator > |
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197 | void fixLastArg( std::list< Expression * > & args, Iterator begin, Iterator end ) { |
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198 | assertf( ! args.empty(), "Somehow args to tuple function are empty" ); // xxx - it's quite possible this will trigger for the nullary case... |
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199 | Expression * last = args.back(); |
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200 | // safe_dynamic_cast for the assertion |
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201 | safe_dynamic_cast< TupleType * >( last->get_result() ); // xxx - it's quite possible this will trigger for the unary case... |
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202 | args.pop_back(); // replace last argument in the call with |
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203 | unsigned idx = 0; |
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204 | for ( ; begin != end; ++begin ) { |
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205 | // DeclarationWithType * formal = *begin; |
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206 | // Type * formalType = formal->get_type(); |
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207 | args.push_back( new TupleIndexExpr( last->clone(), idx++ ) ); |
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208 | } |
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209 | delete last; |
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210 | } |
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211 | |
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212 | Expression * TupleSpecializer::createThunkFunction( FunctionType *funType, Expression *actual, InferredParams *inferParams ) { |
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213 | static UniqueName thunkNamer( "_tupleThunk" ); |
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214 | // std::cerr << "creating tuple thunk for " << funType << std::endl; |
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215 | |
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216 | FunctionType *newType = funType->clone(); |
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217 | if ( env ) { |
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218 | TypeSubstitution newEnv( *env ); |
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219 | // it is important to replace only occurrences of type variables that occur free in the |
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220 | // thunk's type |
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221 | newEnv.applyFree( newType ); |
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222 | } // if |
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223 | // create new thunk with same signature as formal type (C linkage, empty body) |
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224 | FunctionDecl *thunkFunc = new FunctionDecl( thunkNamer.newName(), DeclarationNode::NoStorageClass, LinkageSpec::C, newType, new CompoundStmt( noLabels ), false, false ); |
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225 | thunkFunc->fixUniqueId(); |
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226 | |
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227 | // thunks may be generated and not used - silence warning with attribute |
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228 | thunkFunc->get_attributes().push_back( new Attribute( "unused" ) ); |
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229 | |
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230 | // thread thunk parameters into call to actual function, naming thunk parameters as we go |
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231 | UniqueName paramNamer( paramPrefix ); |
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232 | ApplicationExpr *appExpr = new ApplicationExpr( actual ); |
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233 | // std::cerr << actual << std::endl; |
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234 | |
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235 | FunctionType * actualType = getFunctionType( actual->get_result() ); |
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236 | std::list< DeclarationWithType * >::iterator begin = actualType->get_parameters().begin(); |
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237 | std::list< DeclarationWithType * >::iterator end = actualType->get_parameters().end(); |
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238 | |
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239 | for ( DeclarationWithType* param : thunkFunc->get_functionType()->get_parameters() ) { |
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240 | ++begin; |
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241 | assert( begin != end ); |
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242 | |
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243 | // std::cerr << "thunk param: " << param << std::endl; |
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244 | // last param will always be a tuple type... expand it into the actual type(?) |
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245 | param->set_name( paramNamer.newName() ); |
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246 | appExpr->get_args().push_back( new VariableExpr( param ) ); |
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247 | } // for |
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248 | fixLastArg( appExpr->get_args(), --begin, end ); |
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249 | appExpr->set_env( maybeClone( env ) ); |
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250 | if ( inferParams ) { |
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251 | appExpr->get_inferParams() = *inferParams; |
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252 | } // if |
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253 | |
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254 | // handle any specializations that may still be present |
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255 | std::string oldParamPrefix = paramPrefix; |
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256 | paramPrefix += "p"; |
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257 | // save stmtsToAdd in oldStmts |
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258 | std::list< Statement* > oldStmts; |
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259 | oldStmts.splice( oldStmts.end(), stmtsToAdd ); |
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260 | spec.handleExplicitParams( appExpr ); |
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261 | paramPrefix = oldParamPrefix; |
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262 | // write any statements added for recursive specializations into the thunk body |
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263 | thunkFunc->get_statements()->get_kids().splice( thunkFunc->get_statements()->get_kids().end(), stmtsToAdd ); |
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264 | // restore oldStmts into stmtsToAdd |
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265 | stmtsToAdd.splice( stmtsToAdd.end(), oldStmts ); |
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266 | |
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267 | // add return (or valueless expression) to the thunk |
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268 | Statement *appStmt; |
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269 | if ( funType->get_returnVals().empty() ) { |
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270 | appStmt = new ExprStmt( noLabels, appExpr ); |
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271 | } else { |
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272 | appStmt = new ReturnStmt( noLabels, appExpr ); |
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273 | } // if |
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274 | thunkFunc->get_statements()->get_kids().push_back( appStmt ); |
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275 | |
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276 | // std::cerr << "thunkFunc is: " << thunkFunc << std::endl; |
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277 | |
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278 | // add thunk definition to queue of statements to add |
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279 | stmtsToAdd.push_back( new DeclStmt( noLabels, thunkFunc ) ); |
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280 | // return address of thunk function as replacement expression |
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281 | return new AddressExpr( new VariableExpr( thunkFunc ) ); |
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282 | } |
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283 | |
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284 | void Specialize::handleExplicitParams( ApplicationExpr *appExpr ) { |
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285 | // create thunks for the explicit parameters |
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286 | assert( appExpr->get_function()->has_result() ); |
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287 | FunctionType *function = getFunctionType( appExpr->get_function()->get_result() ); |
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288 | assert( function ); |
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289 | std::list< DeclarationWithType* >::iterator formal; |
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290 | std::list< Expression* >::iterator actual; |
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291 | for ( formal = function->get_parameters().begin(), actual = appExpr->get_args().begin(); formal != function->get_parameters().end() && actual != appExpr->get_args().end(); ++formal, ++actual ) { |
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292 | *actual = specializer->doSpecialization( (*formal )->get_type(), *actual, &appExpr->get_inferParams() ); |
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293 | } |
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294 | } |
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295 | |
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296 | Expression * Specialize::mutate( ApplicationExpr *appExpr ) { |
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297 | appExpr->get_function()->acceptMutator( *this ); |
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298 | mutateAll( appExpr->get_args(), *this ); |
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299 | |
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300 | if ( ! InitTweak::isIntrinsicCallExpr( appExpr ) ) { |
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301 | // create thunks for the inferred parameters |
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302 | // don't need to do this for intrinsic calls, because they aren't actually passed |
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303 | for ( InferredParams::iterator inferParam = appExpr->get_inferParams().begin(); inferParam != appExpr->get_inferParams().end(); ++inferParam ) { |
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304 | inferParam->second.expr = specializer->doSpecialization( inferParam->second.formalType, inferParam->second.expr, &appExpr->get_inferParams() ); |
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305 | } |
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306 | handleExplicitParams( appExpr ); |
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307 | } |
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308 | return appExpr; |
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309 | } |
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310 | |
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311 | Expression * Specialize::mutate( AddressExpr *addrExpr ) { |
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312 | addrExpr->get_arg()->acceptMutator( *this ); |
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313 | assert( addrExpr->has_result() ); |
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314 | addrExpr->set_arg( specializer->doSpecialization( addrExpr->get_result(), addrExpr->get_arg() ) ); |
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315 | return addrExpr; |
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316 | } |
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317 | |
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318 | Expression * Specialize::mutate( CastExpr *castExpr ) { |
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319 | castExpr->get_arg()->acceptMutator( *this ); |
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320 | if ( castExpr->get_result()->isVoid() ) { |
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321 | // can't specialize if we don't have a return value |
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322 | return castExpr; |
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323 | } |
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324 | Expression *specialized = specializer->doSpecialization( castExpr->get_result(), castExpr->get_arg() ); |
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325 | if ( specialized != castExpr->get_arg() ) { |
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326 | // assume here that the specialization incorporates the cast |
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327 | return specialized; |
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328 | } else { |
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329 | return castExpr; |
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330 | } |
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331 | } |
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332 | |
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333 | // Removing these for now. Richard put these in for some reason, but it's not clear why. |
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334 | // In particular, copy constructors produce a comma expression, and with this code the parts |
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335 | // of that comma expression are not specialized, which causes problems. |
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336 | |
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337 | // Expression * Specialize::mutate( LogicalExpr *logicalExpr ) { |
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338 | // return logicalExpr; |
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339 | // } |
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340 | |
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341 | // Expression * Specialize::mutate( ConditionalExpr *condExpr ) { |
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342 | // return condExpr; |
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343 | // } |
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344 | |
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345 | // Expression * Specialize::mutate( CommaExpr *commaExpr ) { |
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346 | // return commaExpr; |
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347 | // } |
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348 | |
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349 | void convertSpecializations( std::list< Declaration* >& translationUnit ) { |
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350 | Specialize spec; |
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351 | |
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352 | TupleSpecializer tupleSpec( spec ); |
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353 | spec.specializer = &tupleSpec; |
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354 | mutateAll( translationUnit, spec ); |
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355 | |
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356 | PolySpecializer polySpec( spec ); |
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357 | spec.specializer = &polySpec; |
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358 | mutateAll( translationUnit, spec ); |
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359 | } |
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360 | } // namespace GenPoly |
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361 | |
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362 | // Local Variables: // |
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363 | // tab-width: 4 // |
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364 | // mode: c++ // |
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365 | // compile-command: "make install" // |
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366 | // End: // |
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