| 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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