source: src/ResolvExpr/Cost.h@ 8f6f3729

ADT ast-experimental enum forall-pointer-decay jacob/cs343-translation new-ast-unique-expr pthread-emulation qualifiedEnum
Last change on this file since 8f6f3729 was 9504a89, checked in by Peter A. Buhr <pabuhr@…>, 6 years ago

remove old code for costing
  • Property mode set to 100644
File size: 6.1 KB
Line 
1//
2// Cforall Version 1.0.0 Copyright (C) 2015 University of Waterloo
3//
4// The contents of this file are covered under the licence agreement in the
5// file "LICENCE" distributed with Cforall.
6//
7// Cost.h --
8//
9// Author : Peter Buhr and Aaron Moss
10// Created On : Sun May 17 09:39:50 2015
11// Last Modified By : Peter A. Buhr
12// Last Modified On : Fri Jun 21 11:39:13 2019
13// Update Count : 63
14//
15
16#pragma once
17
18#include <iostream>
19#include <cassert>
20#include <climits>
21
22namespace ResolvExpr {
23 // To maximize performance and space, the 7 resolution costs are packed into a single 64-bit word. However, the
24 // specialization cost is a negative value so a correction is needed is a few places.
25
26 class Cost {
27 union {
28 struct {
29 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
30 // Little-endian => first value is low priority and last is high priority.
31 unsigned char padding; ///< unused
32 unsigned char referenceCost; ///< reference conversions
33 unsigned char specCost; ///< Polymorphic type specializations (type assertions), negative cost
34 unsigned char varCost; ///< Count of polymorphic type variables
35 unsigned char signCost; ///< Count of safe sign conversions
36 unsigned char safeCost; ///< Safe (widening) conversions
37 unsigned char polyCost; ///< Count of parameters and return values bound to some poly type
38 unsigned char unsafeCost; ///< Unsafe (narrowing) conversions
39 #else
40 #error Cost BIG_ENDIAN unsupported
41 #endif
42 } v;
43 uint64_t all;
44 };
45 static const unsigned char correctb = 0xff; // byte correction for negative spec cost
46 static const uint64_t correctw = 0x00'00'00'00'00'ff'00'00; //' word correction for negative spec cost
47 public:
48 // Compiler adjusts constants for correct endian.
49 enum : uint64_t {
50 zero = 0x00'00'00'00'00'ff'00'00,
51 infinity = 0xff'ff'ff'ff'ff'00'ff'ff,
52 unsafe = 0x01'00'00'00'00'ff'00'00,
53 poly = 0x00'01'00'00'00'ff'00'00,
54 safe = 0x00'00'01'00'00'ff'00'00,
55 sign = 0x00'00'00'01'00'ff'00'00,
56 var = 0x00'00'00'00'01'ff'00'00,
57 spec = 0x00'00'00'00'00'fe'00'00,
58 reference = 0x00'00'00'00'00'ff'01'00,
59 }; //'
60
61 Cost( uint64_t all ) { Cost::all = all; }
62 Cost( int unsafeCost, int polyCost, int safeCost, int signCost, int varCost, int specCost, int referenceCost ) {
63 // Assume little-endian => first value is low priority and last is high priority.
64 v = {
65 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
66 (unsigned char)0, // padding
67 (unsigned char)referenceCost, // low priority
68 (unsigned char)(specCost + correctb), // correct for signedness
69 (unsigned char)varCost,
70 (unsigned char)signCost,
71 (unsigned char)safeCost,
72 (unsigned char)polyCost,
73 (unsigned char)unsafeCost, // high priority
74 #else
75 #error Cost BIG_ENDIAN unsupported
76 #endif
77 };
78 }
79
80 int get_unsafeCost() const { return v.unsafeCost; }
81 int get_polyCost() const { return v.polyCost; }
82 int get_safeCost() const { return v.safeCost; }
83 int get_signCost() const { return v.signCost; }
84 int get_varCost() const { return v.varCost; }
85 int get_specCost() const { return -(correctb - v.specCost); }
86 int get_referenceCost() const { return v.referenceCost; }
87
88 friend bool operator==( const Cost, const Cost );
89 friend bool operator!=( const Cost lhs, const Cost rhs );
90 // returns negative for *this < rhs, 0 for *this == rhs, positive for *this > rhs
91 int compare( const Cost rhs ) const {
92 if ( all == infinity ) return 1;
93 if ( rhs.all == infinity ) return -1;
94 return all > rhs.all ? 1 : all == rhs.all ? 0 : -1;
95 }
96 friend bool operator<( const Cost lhs, const Cost rhs );
97
98 friend Cost operator+( const Cost lhs, const Cost rhs );
99
100 Cost operator+=( const Cost rhs ) {
101 if ( all == infinity ) return *this;
102 if ( rhs.all == infinity ) {
103 all = infinity;
104 return *this;
105 }
106 all += rhs.all - correctw; // correct for negative spec cost
107 return *this;
108 }
109
110 Cost incUnsafe( int inc = 1 ) {
111 if ( all != infinity ) { assert( v.unsafeCost + inc <= UCHAR_MAX ); v.unsafeCost += inc; }
112 return *this;
113 }
114
115 Cost incPoly( int inc = 1 ) {
116 if ( all != infinity ) { assert( v.polyCost + inc <= UCHAR_MAX ); v.polyCost += inc; }
117 return *this;
118 }
119
120 Cost incSafe( int inc = 1 ) {
121 if ( all != infinity ) { assert( v.safeCost + inc <= UCHAR_MAX ); v.safeCost += inc; }
122 return *this;
123 }
124
125 Cost incSign( int inc = 1 ) {
126 if ( all != infinity ) { assert( v.signCost + inc <= UCHAR_MAX ); v.signCost += inc; }
127 return *this;
128 }
129
130 Cost incVar( int inc = 1 ) {
131 if ( all != infinity ) { assert( v.varCost + inc <= UCHAR_MAX ); v.varCost += inc; }
132 return *this;
133 }
134
135 Cost decSpec( int dec = 1 ) {
136 if ( all != infinity ) { assert( v.specCost - dec >= 0 ); v.specCost -= dec; }
137 return *this;
138 }
139
140 Cost incReference( int inc = 1 ) {
141 if ( all != infinity ) { assert( v.referenceCost + inc <= UCHAR_MAX ); v.referenceCost += inc; }
142 return *this;
143 }
144
145 friend std::ostream & operator<<( std::ostream & os, const Cost cost );
146 };
147
148 inline bool operator==( const Cost lhs, const Cost rhs ) {
149 return lhs.all == rhs.all;
150 }
151
152 inline bool operator!=( const Cost lhs, const Cost rhs ) {
153 return !( lhs.all == rhs.all );
154 }
155
156 inline bool operator<( const Cost lhs, const Cost rhs ) {
157 if ( lhs.all == Cost::infinity ) return false;
158 if ( rhs.all == Cost::infinity ) return true;
159 return lhs.all < rhs.all;
160 }
161
162 inline Cost operator+( const Cost lhs, const Cost rhs ) {
163 if ( lhs.all == Cost::infinity || rhs.all == Cost::infinity ) return Cost{ Cost::infinity };
164 return Cost{ lhs.all + rhs.all - Cost::correctw }; // correct for negative spec cost
165 }
166
167 inline std::ostream & operator<<( std::ostream & os, const Cost cost ) {
168 return os << "( " << cost.get_unsafeCost() << ", " << cost.get_polyCost() << ", " << cost.get_safeCost()
169 << ", " << cost.get_signCost() << ", " << cost.get_varCost() << ", " << cost.get_specCost()
170 << ", " << cost.get_referenceCost() << " )";
171 }
172} // namespace ResolvExpr
173
174// Local Variables: //
175// tab-width: 4 //
176// mode: c++ //
177// compile-command: "make install" //
178// End: //
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