source: src/ResolvExpr/Cost.hpp@ 4d5c5b6a

Last change on this file since 4d5c5b6a was 06ecda9, checked in by JiadaL <j82liang@…>, 14 months ago

define enum to value cost as implicit cost
  • Property mode set to 100644
File size: 6.3 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 May 3 17:15:41 2024
13// Update Count : 64
14//
15
16#pragma once
17
18#include <iostream>
19#include <cassert>
20#include <climits>
21#include <cstdint>
22
23namespace ResolvExpr {
24
25// To maximize performance and space, the 7 resolution costs are packed into a single 64-bit word. However, the
26// specialization cost is a negative value so a correction is needed is a few places.
27
28class Cost {
29 union {
30 struct {
31 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
32 // Little-endian => first value is low priority and last is high priority.
33 unsigned char referenceCost; ///< reference conversions
34 unsigned char specCost; ///< Polymorphic type specializations (type assertions), negative cost
35 unsigned char varCost; ///< Count of polymorphic type variables
36 unsigned char signCost; ///< Count of safe sign conversions
37 unsigned char safeCost; ///< Safe (widening) conversions
38 unsigned char polyCost; ///< Count of parameters and return values bound to some poly type
39 unsigned char implicitCost; ///< Aggregate implicit cost
40 unsigned char unsafeCost; ///< Unsafe (narrowing) conversions
41 #else
42 #error Cost BIG_ENDIAN unsupported
43 #endif
44 } v;
45 uint64_t all;
46 };
47 static const unsigned char correctb = 0xff; // byte correction for negative spec cost
48 static const uint64_t correctw = 0x00'00'00'00'00'00'ff'00; //' word correction for negative spec cost
49 public:
50 // Compiler adjusts constants for correct endian.
51 enum : uint64_t {
52 zero = 0x00'00'00'00'00'00'ff'00,
53 infinity = 0xff'ff'ff'ff'ff'ff'00'ff,
54 unsafe = 0x01'00'00'00'00'00'ff'00,
55 implicit = 0x00'01'00'00'01'00'ff'00,
56 poly = 0x00'00'01'00'00'00'ff'00,
57 safe = 0x00'00'00'01'00'00'ff'00,
58 sign = 0x00'00'00'00'01'00'ff'00,
59 var = 0x00'00'00'00'00'01'ff'00,
60 spec = 0x00'00'00'00'00'00'fe'00,
61 reference = 0x00'00'00'00'00'00'ff'01,
62 }; //'
63
64 Cost( uint64_t all ) { Cost::all = all; }
65 Cost( int unsafeCost, int polyCost, int safeCost, int signCost, int implicitCost, int varCost, int specCost, int referenceCost ) {
66 // Assume little-endian => first value is low priority and last is high priority.
67 v = {
68 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
69 (unsigned char)referenceCost, // low priority
70 (unsigned char)(specCost + correctb), // correct for signedness
71 (unsigned char)varCost,
72 (unsigned char)signCost,
73 (unsigned char)safeCost,
74 (unsigned char)polyCost,
75 (unsigned char)implicitCost,
76 (unsigned char)unsafeCost, // high priority
77 #else
78 #error Cost BIG_ENDIAN unsupported
79 #endif
80 };
81 }
82
83 int get_unsafeCost() const { return v.unsafeCost; }
84 int get_implictCost() const { return v.implicitCost; }
85 int get_polyCost() const { return v.polyCost; }
86 int get_safeCost() const { return v.safeCost; }
87 int get_signCost() const { return v.signCost; }
88 int get_varCost() const { return v.varCost; }
89 int get_specCost() const { return -(correctb - v.specCost); }
90 int get_referenceCost() const { return v.referenceCost; }
91
92 friend bool operator==( const Cost, const Cost );
93 friend bool operator!=( const Cost lhs, const Cost rhs );
94 // returns negative for *this < rhs, 0 for *this == rhs, positive for *this > rhs
95 int compare( const Cost rhs ) const {
96 if ( all == infinity ) return 1;
97 if ( rhs.all == infinity ) return -1;
98 return all > rhs.all ? 1 : all == rhs.all ? 0 : -1;
99 }
100 friend bool operator<( const Cost lhs, const Cost rhs );
101
102 friend Cost operator+( const Cost lhs, const Cost rhs );
103
104 Cost operator+=( const Cost rhs ) {
105 if ( all == infinity ) return *this;
106 if ( rhs.all == infinity ) {
107 all = infinity;
108 return *this;
109 }
110 all += rhs.all - correctw; // correct for negative spec cost
111 return *this;
112 }
113
114 Cost incUnsafe( int inc = 1 ) {
115 if ( all != infinity ) { assert( v.unsafeCost + inc <= UCHAR_MAX ); v.unsafeCost += inc; }
116 return *this;
117 }
118
119 Cost incImplicit( int inc = 1 ) {
120 if ( all != infinity ) { assert( v.implicitCost + inc <= UCHAR_MAX ); v.implicitCost += inc; }
121 return *this;
122 }
123
124 Cost incPoly( int inc = 1 ) {
125 if ( all != infinity ) { assert( v.polyCost + inc <= UCHAR_MAX ); v.polyCost += inc; }
126 return *this;
127 }
128
129 Cost incSafe( int inc = 1 ) {
130 if ( all != infinity ) { assert( v.safeCost + inc <= UCHAR_MAX ); v.safeCost += inc; }
131 return *this;
132 }
133
134 Cost incSign( int inc = 1 ) {
135 if ( all != infinity ) { assert( v.signCost + inc <= UCHAR_MAX ); v.signCost += inc; }
136 return *this;
137 }
138
139 Cost incVar( int inc = 1 ) {
140 if ( all != infinity ) { assert( v.varCost + inc <= UCHAR_MAX ); v.varCost += inc; }
141 return *this;
142 }
143
144 Cost decSpec( int dec = 1 ) {
145 if ( all != infinity ) { assert( v.specCost - dec >= 0 ); v.specCost -= dec; }
146 return *this;
147 }
148
149 Cost incReference( int inc = 1 ) {
150 if ( all != infinity ) { assert( v.referenceCost + inc <= UCHAR_MAX ); v.referenceCost += inc; }
151 return *this;
152 }
153
154 friend std::ostream & operator<<( std::ostream & os, const Cost cost );
155};
156
157inline bool operator==( const Cost lhs, const Cost rhs ) {
158 return lhs.all == rhs.all;
159}
160
161inline bool operator!=( const Cost lhs, const Cost rhs ) {
162 return !( lhs.all == rhs.all );
163}
164
165inline bool operator<( const Cost lhs, const Cost rhs ) {
166 if ( lhs.all == Cost::infinity ) return false;
167 if ( rhs.all == Cost::infinity ) return true;
168 return lhs.all < rhs.all;
169}
170
171inline Cost operator+( const Cost lhs, const Cost rhs ) {
172 if ( lhs.all == Cost::infinity || rhs.all == Cost::infinity ) return Cost{ Cost::infinity };
173 return Cost{ lhs.all + rhs.all - Cost::correctw }; // correct for negative spec cost
174}
175
176inline std::ostream & operator<<( std::ostream & os, const Cost cost ) {
177 return os << "( " << cost.get_unsafeCost() << ", " << cost.get_implictCost() << ", " << cost.get_polyCost() << ", " << cost.get_safeCost()
178 << ", " << cost.get_signCost() << ", " << cost.get_varCost() << ", " << cost.get_specCost()
179 << ", " << cost.get_referenceCost() << " )";
180}
181
182} // namespace ResolvExpr
183
184// Local Variables: //
185// tab-width: 4 //
186// mode: c++ //
187// compile-command: "make install" //
188// End: //
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