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 | // Cost.h -- |
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8 | // |
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9 | // Author : Peter Buhr and Aaron Moss |
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10 | // Created On : Sun May 17 09:39:50 2015 |
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11 | // Last Modified By : Peter A. Buhr |
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12 | // Last Modified On : Mon Apr 29 18:33:44 2019 |
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13 | // Update Count : 49 |
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14 | // |
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15 | |
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16 | #pragma once |
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17 | |
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18 | #include <iostream> |
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19 | #include <cassert> |
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20 | #include <climits> |
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21 | |
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22 | namespace ResolvExpr { |
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23 | #if 0 |
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24 | |
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25 | //*************************** OLD *************************** |
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26 | |
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27 | class Cost { |
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28 | private: |
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29 | Cost( int unsafeCost, int polyCost, int safeCost, int signCost, |
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30 | int varCost, int specCost, int referenceCost ); |
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31 | public: |
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32 | Cost & incUnsafe( int inc = 1 ); |
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33 | Cost & incPoly( int inc = 1 ); |
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34 | Cost & incSafe( int inc = 1 ); |
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35 | Cost & incSign( int inc = 1 ); |
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36 | Cost & incVar( int inc = 1 ); |
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37 | Cost & decSpec( int inc = 1 ); |
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38 | Cost & incReference( int inc = 1 ); |
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39 | |
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40 | int get_unsafeCost() const { return unsafeCost; } |
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41 | int get_polyCost() const { return polyCost; } |
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42 | int get_safeCost() const { return safeCost; } |
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43 | int get_signCost() const { return signCost; } |
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44 | int get_varCost() const { return varCost; } |
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45 | int get_specCost() const { return specCost; } |
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46 | int get_referenceCost() const { return referenceCost; } |
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47 | |
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48 | Cost operator+( const Cost &other ) const; |
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49 | Cost &operator+=( const Cost &other ); |
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50 | bool operator<( const Cost &other ) const; |
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51 | bool operator==( const Cost &other ) const; |
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52 | bool operator!=( const Cost &other ) const; |
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53 | friend std::ostream &operator<<( std::ostream &os, const Cost &cost ); |
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54 | // returns negative for *this < other, 0 for *this == other, positive for *this > other |
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55 | int compare( const Cost &other ) const; |
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56 | |
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57 | static const Cost zero; |
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58 | static const Cost infinity; |
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59 | |
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60 | static const Cost unsafe; |
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61 | static const Cost poly; |
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62 | static const Cost safe; |
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63 | static const Cost sign; |
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64 | static const Cost var; |
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65 | static const Cost spec; |
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66 | static const Cost reference; |
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67 | |
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68 | private: |
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69 | int unsafeCost; ///< Unsafe (narrowing) conversions |
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70 | int polyCost; ///< Count of parameters and return values bound to some poly type |
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71 | int safeCost; ///< Safe (widening) conversions |
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72 | int signCost; ///< Count of safe sign conversions |
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73 | int varCost; ///< Count of polymorphic type variables |
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74 | int specCost; ///< Polymorphic type specializations (type assertions), negative cost |
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75 | int referenceCost; ///< reference conversions |
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76 | }; |
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77 | |
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78 | inline Cost::Cost( int unsafeCost, int polyCost, int safeCost, int signCost, |
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79 | int varCost, int specCost, int referenceCost ) |
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80 | : unsafeCost( unsafeCost ), polyCost( polyCost ), safeCost( safeCost ), signCost( signCost ), |
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81 | varCost( varCost ), specCost( specCost ), referenceCost( referenceCost ) {} |
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82 | |
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83 | inline Cost & Cost::incUnsafe( int inc ) { |
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84 | if ( *this == infinity ) return *this; |
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85 | unsafeCost += inc; |
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86 | return *this; |
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87 | } |
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88 | |
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89 | inline Cost & Cost::incPoly( int inc ) { |
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90 | if ( *this == infinity ) return *this; |
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91 | polyCost += inc; |
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92 | return *this; |
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93 | } |
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94 | |
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95 | inline Cost & Cost::incSafe( int inc ) { |
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96 | if ( *this == infinity ) return *this; |
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97 | safeCost += inc; |
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98 | return *this; |
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99 | } |
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100 | |
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101 | inline Cost & Cost::incSign( int inc ) { |
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102 | if ( *this == infinity ) return *this; |
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103 | signCost += inc; |
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104 | return *this; |
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105 | } |
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106 | |
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107 | inline Cost & Cost::incVar( int inc ) { |
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108 | if ( *this == infinity ) return *this; |
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109 | varCost += inc; |
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110 | return *this; |
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111 | } |
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112 | |
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113 | inline Cost& Cost::decSpec( int dec ) { |
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114 | if ( *this == infinity ) return *this; |
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115 | specCost -= dec; |
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116 | return *this; |
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117 | } |
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118 | |
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119 | inline Cost & Cost::incReference( int inc ) { |
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120 | if ( *this == infinity ) return *this; |
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121 | referenceCost += inc; |
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122 | return *this; |
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123 | } |
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124 | |
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125 | inline Cost Cost::operator+( const Cost &other ) const { |
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126 | if ( *this == infinity || other == infinity ) return infinity; |
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127 | return Cost{ |
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128 | unsafeCost + other.unsafeCost, polyCost + other.polyCost, safeCost + other.safeCost, |
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129 | signCost + other.signCost, varCost + other.varCost, specCost + other.specCost, |
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130 | referenceCost + other.referenceCost }; |
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131 | } |
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132 | |
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133 | inline Cost &Cost::operator+=( const Cost &other ) { |
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134 | if ( *this == infinity ) return *this; |
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135 | if ( other == infinity ) { |
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136 | *this = infinity; |
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137 | return *this; |
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138 | } |
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139 | unsafeCost += other.unsafeCost; |
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140 | polyCost += other.polyCost; |
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141 | safeCost += other.safeCost; |
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142 | signCost += other.signCost; |
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143 | varCost += other.varCost; |
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144 | specCost += other.specCost; |
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145 | referenceCost += other.referenceCost; |
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146 | return *this; |
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147 | } |
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148 | |
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149 | inline bool Cost::operator<( const Cost &other ) const { |
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150 | if ( *this == infinity ) return false; |
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151 | if ( other == infinity ) return true; |
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152 | |
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153 | if ( unsafeCost > other.unsafeCost ) { |
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154 | return false; |
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155 | } else if ( unsafeCost < other.unsafeCost ) { |
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156 | return true; |
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157 | } else if ( polyCost > other.polyCost ) { |
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158 | return false; |
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159 | } else if ( polyCost < other.polyCost ) { |
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160 | return true; |
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161 | } else if ( safeCost > other.safeCost ) { |
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162 | return false; |
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163 | } else if ( safeCost < other.safeCost ) { |
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164 | return true; |
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165 | } else if ( signCost > other.signCost ) { |
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166 | return false; |
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167 | } else if ( signCost < other.signCost ) { |
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168 | return true; |
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169 | } else if ( varCost > other.varCost ) { |
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170 | return false; |
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171 | } else if ( varCost < other.varCost ) { |
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172 | return true; |
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173 | } else if ( specCost > other.specCost ) { |
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174 | return false; |
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175 | } else if ( specCost > other.specCost ) { |
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176 | return true; |
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177 | } else if ( referenceCost > other.referenceCost ) { |
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178 | return false; |
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179 | } else if ( referenceCost < other.referenceCost ) { |
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180 | return true; |
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181 | } else { |
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182 | return false; |
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183 | } // if |
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184 | } |
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185 | |
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186 | inline int Cost::compare( const Cost &other ) const { |
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187 | if ( *this == infinity ) return +1; |
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188 | if ( other == infinity ) return -1; |
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189 | |
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190 | int c = unsafeCost - other.unsafeCost; if ( c ) return c; |
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191 | c = polyCost - other.polyCost; if ( c ) return c; |
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192 | c = safeCost - other.safeCost; if ( c ) return c; |
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193 | c = signCost - other.signCost; if ( c ) return c; |
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194 | c = varCost - other.varCost; if ( c ) return c; |
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195 | c = specCost - other.specCost; if ( c ) return c; |
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196 | return referenceCost - other.referenceCost; |
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197 | } |
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198 | |
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199 | inline bool Cost::operator==( const Cost &other ) const { |
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200 | return unsafeCost == other.unsafeCost |
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201 | && polyCost == other.polyCost |
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202 | && safeCost == other.safeCost |
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203 | && signCost == other.signCost |
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204 | && varCost == other.varCost |
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205 | && specCost == other.specCost |
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206 | && referenceCost == other.referenceCost; |
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207 | } |
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208 | |
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209 | inline bool Cost::operator!=( const Cost &other ) const { |
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210 | return !( *this == other ); |
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211 | } |
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212 | |
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213 | inline std::ostream &operator<<( std::ostream &os, const Cost &cost ) { |
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214 | return os << "( " << cost.unsafeCost << ", " << cost.polyCost << ", " |
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215 | << cost.safeCost << ", " << cost.signCost << ", " |
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216 | << cost.varCost << ", " << cost.specCost << ", " |
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217 | << cost.referenceCost << " )"; |
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218 | } |
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219 | |
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220 | #else |
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221 | |
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222 | //*************************** NEW *************************** |
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223 | |
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224 | // To maximize performance and space, the 7 resolution costs are packed into a single 64-bit word. However, the |
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225 | // specialization cost is a negative value so a correction is needed is a few places. |
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226 | |
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227 | class Cost { |
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228 | union { |
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229 | struct { |
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230 | #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ |
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231 | // Little-endian => first value is low priority and last is high priority. |
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232 | unsigned char padding; ///< unused |
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233 | unsigned char referenceCost; ///< reference conversions |
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234 | unsigned char specCost; ///< Polymorphic type specializations (type assertions), negative cost |
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235 | unsigned char varCost; ///< Count of polymorphic type variables |
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236 | unsigned char signCost; ///< Count of safe sign conversions |
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237 | unsigned char safeCost; ///< Safe (widening) conversions |
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238 | unsigned char polyCost; ///< Count of parameters and return values bound to some poly type |
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239 | unsigned char unsafeCost; ///< Unsafe (narrowing) conversions |
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240 | #else |
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241 | #error Cost BIG_ENDIAN unsupported |
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242 | #endif |
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243 | } v; |
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244 | uint64_t all; |
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245 | }; |
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246 | static const unsigned char correctb = 0xff; // byte correction for negative spec cost |
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247 | static const uint64_t correctw = 0x00'00'00'00'00'ff'00'00; //' word correction for negative spec cost |
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248 | public: |
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249 | // Compiler adjusts constants for correct endian. |
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250 | enum : uint64_t { |
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251 | zero = 0x00'00'00'00'00'ff'00'00, |
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252 | infinity = 0xff'ff'ff'ff'ff'00'ff'ff, |
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253 | unsafe = 0x01'00'00'00'00'ff'00'00, |
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254 | poly = 0x00'01'00'00'00'ff'00'00, |
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255 | safe = 0x00'00'01'00'00'ff'00'00, |
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256 | sign = 0x00'00'00'01'00'ff'00'00, |
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257 | var = 0x00'00'00'00'01'ff'00'00, |
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258 | spec = 0x00'00'00'00'00'fe'00'00, |
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259 | reference = 0x00'00'00'00'00'ff'01'00, |
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260 | }; //' |
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261 | |
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262 | Cost( uint64_t all ) { Cost::all = all; } |
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263 | Cost( int unsafeCost, int polyCost, int safeCost, int signCost, int varCost, int specCost, int referenceCost ) { |
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264 | // Assume little-endian => first value is low priority and last is high priority. |
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265 | v = { |
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266 | #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ |
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267 | (unsigned char)0, // padding |
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268 | (unsigned char)referenceCost, // low priority |
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269 | (unsigned char)(specCost + correctb), // correct for signedness |
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270 | (unsigned char)varCost, |
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271 | (unsigned char)signCost, |
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272 | (unsigned char)safeCost, |
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273 | (unsigned char)polyCost, |
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274 | (unsigned char)unsafeCost, // high priority |
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275 | #else |
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276 | #error Cost BIG_ENDIAN unsupported |
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277 | #endif |
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278 | }; |
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279 | } |
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280 | |
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281 | int get_unsafeCost() const { return v.unsafeCost; } |
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282 | int get_polyCost() const { return v.polyCost; } |
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283 | int get_safeCost() const { return v.safeCost; } |
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284 | int get_signCost() const { return v.signCost; } |
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285 | int get_varCost() const { return v.varCost; } |
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286 | int get_specCost() const { return -(correctb - v.specCost); } |
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287 | int get_referenceCost() const { return v.referenceCost; } |
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288 | |
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289 | friend bool operator==( const Cost, const Cost ); |
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290 | friend bool operator!=( const Cost lhs, const Cost rhs ); |
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291 | // returns negative for *this < rhs, 0 for *this == rhs, positive for *this > rhs |
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292 | int compare( const Cost rhs ) const { |
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293 | if ( all == infinity ) return 1; |
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294 | if ( rhs.all == infinity ) return -1; |
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295 | return all > rhs.all ? 1 : all == rhs.all ? 0 : -1; |
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296 | } |
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297 | friend bool operator<( const Cost lhs, const Cost rhs ); |
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298 | |
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299 | friend Cost operator+( const Cost lhs, const Cost rhs ); |
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300 | |
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301 | Cost operator+=( const Cost rhs ) { |
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302 | if ( all == infinity ) return *this; |
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303 | if ( rhs.all == infinity ) { |
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304 | all = infinity; |
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305 | return *this; |
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306 | } |
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307 | all += rhs.all - correctw; // correct for negative spec cost |
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308 | return *this; |
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309 | } |
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310 | |
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311 | Cost incUnsafe( int inc = 1 ) { |
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312 | if ( all != infinity ) { assert( v.unsafeCost + inc <= UCHAR_MAX ); v.unsafeCost += inc; } |
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313 | return *this; |
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314 | } |
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315 | |
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316 | Cost incPoly( int inc = 1 ) { |
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317 | if ( all != infinity ) { assert( v.polyCost + inc <= UCHAR_MAX ); v.polyCost += inc; } |
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318 | return *this; |
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319 | } |
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320 | |
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321 | Cost incSafe( int inc = 1 ) { |
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322 | if ( all != infinity ) { assert( v.safeCost + inc <= UCHAR_MAX ); v.safeCost += inc; } |
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323 | return *this; |
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324 | } |
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325 | |
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326 | Cost incSign( int inc = 1 ) { |
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327 | if ( all != infinity ) { assert( v.signCost + inc <= UCHAR_MAX ); v.signCost += inc; } |
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328 | return *this; |
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329 | } |
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330 | |
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331 | Cost incVar( int inc = 1 ) { |
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332 | if ( all != infinity ) { assert( v.varCost + inc <= UCHAR_MAX ); v.varCost += inc; } |
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333 | return *this; |
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334 | } |
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335 | |
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336 | Cost decSpec( int dec = 1 ) { |
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337 | if ( all != infinity ) { assert( v.specCost - dec >= 0 ); v.specCost -= dec; } |
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338 | return *this; |
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339 | } |
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340 | |
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341 | Cost incReference( int inc = 1 ) { |
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342 | if ( all != infinity ) { assert( v.referenceCost + inc <= UCHAR_MAX ); v.referenceCost += inc; } |
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343 | return *this; |
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344 | } |
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345 | |
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346 | friend std::ostream & operator<<( std::ostream & os, const Cost cost ); |
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347 | }; |
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348 | |
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349 | inline bool operator==( const Cost lhs, const Cost rhs ) { |
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350 | return lhs.all == rhs.all; |
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351 | } |
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352 | |
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353 | inline bool operator!=( const Cost lhs, const Cost rhs ) { |
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354 | return !( lhs.all == rhs.all ); |
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355 | } |
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356 | |
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357 | inline bool operator<( const Cost lhs, const Cost rhs ) { |
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358 | if ( lhs.all == Cost::infinity ) return false; |
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359 | if ( rhs.all == Cost::infinity ) return true; |
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360 | return lhs.all < rhs.all; |
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361 | } |
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362 | |
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363 | inline Cost operator+( const Cost lhs, const Cost rhs ) { |
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364 | if ( lhs.all == Cost::infinity || rhs.all == Cost::infinity ) return Cost{ Cost::infinity }; |
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365 | return Cost{ lhs.all + rhs.all - Cost::correctw }; // correct for negative spec cost |
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366 | } |
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367 | |
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368 | inline std::ostream & operator<<( std::ostream & os, const Cost cost ) { |
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369 | return os << "( " << cost.get_unsafeCost() << ", " << cost.get_polyCost() << ", " << cost.get_safeCost() |
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370 | << ", " << cost.get_signCost() << ", " << cost.get_varCost() << ", " << cost.get_specCost() |
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371 | << ", " << cost.get_referenceCost() << " )"; |
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372 | } |
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373 | #endif // 0 |
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374 | } // namespace ResolvExpr |
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375 | |
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376 | // Local Variables: // |
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377 | // tab-width: 4 // |
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378 | // mode: c++ // |
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379 | // compile-command: "make install" // |
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380 | // End: // |
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