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1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. | 1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. |
2 // Use of this source code is governed by a BSD-style license that can be | 2 // Use of this source code is governed by a BSD-style license that can be |
3 // found in the LICENSE file. | 3 // found in the LICENSE file. |
4 | 4 |
5 #ifndef NET_BASE_INT128_H_ | 5 #ifndef NET_BASE_INT128_H_ |
6 #define NET_BASE_INT128_H_ | 6 #define NET_BASE_INT128_H_ |
7 | 7 |
8 #include <iosfwd> | 8 #include <iosfwd> |
9 #include "base/basictypes.h" | 9 #include "base/basictypes.h" |
10 #include "net/base/net_export.h" | 10 #include "net/base/net_export.h" |
11 | 11 |
12 struct uint128_pod; | 12 struct uint128_pod; |
13 | 13 |
14 // An unsigned 128-bit integer type. Thread-compatible. | 14 // An unsigned 128-bit integer type. Thread-compatible. |
15 class uint128 { | 15 class uint128 { |
16 public: | 16 public: |
17 uint128(); // Sets to 0, but don't trust on this behavior. | 17 uint128(); // Sets to 0, but don't trust on this behavior. |
18 uint128(uint64 top, uint64 bottom); | 18 uint128(uint64 top, uint64 bottom); |
19 uint128(int bottom); | 19 uint128(int bottom); |
20 uint128(uint32 bottom); // Top 96 bits = 0 | 20 uint128(uint32 bottom); // Top 96 bits = 0 |
21 uint128(uint64 bottom); // hi_ = 0 | 21 uint128(uint64 bottom); // hi_ = 0 |
22 uint128(const uint128 &val); | 22 uint128(const uint128& val); |
23 uint128(const uint128_pod &val); | 23 uint128(const uint128_pod& val); |
24 | 24 |
25 void Initialize(uint64 top, uint64 bottom); | 25 void Initialize(uint64 top, uint64 bottom); |
26 | 26 |
27 uint128& operator=(const uint128& b); | 27 uint128& operator=(const uint128& b); |
28 | 28 |
29 // Arithmetic operators. | 29 // Arithmetic operators. |
30 // TODO: division, etc. | 30 // TODO: division, etc. |
31 uint128& operator+=(const uint128& b); | 31 uint128& operator+=(const uint128& b); |
32 uint128& operator-=(const uint128& b); | 32 uint128& operator-=(const uint128& b); |
33 uint128& operator*=(const uint128& b); | 33 uint128& operator*=(const uint128& b); |
34 uint128 operator++(int); | 34 uint128 operator++(int); |
35 uint128 operator--(int); | 35 uint128 operator--(int); |
36 uint128& operator<<=(int); | 36 uint128& operator<<=(int); |
37 uint128& operator>>=(int); | 37 uint128& operator>>=(int); |
38 uint128& operator&=(const uint128& b); | 38 uint128& operator&=(const uint128& b); |
39 uint128& operator|=(const uint128& b); | 39 uint128& operator|=(const uint128& b); |
40 uint128& operator^=(const uint128& b); | 40 uint128& operator^=(const uint128& b); |
41 uint128& operator++(); | 41 uint128& operator++(); |
42 uint128& operator--(); | 42 uint128& operator--(); |
43 | 43 |
44 friend uint64 Uint128Low64(const uint128& v); | 44 friend uint64 Uint128Low64(const uint128& v); |
45 friend uint64 Uint128High64(const uint128& v); | 45 friend uint64 Uint128High64(const uint128& v); |
46 | 46 |
47 // We add "std::" to avoid including all of port.h. | 47 // We add "std::" to avoid including all of port.h. |
48 friend NET_EXPORT_PRIVATE std::ostream& operator<<(std::ostream& o, | 48 friend NET_EXPORT_PRIVATE std::ostream& operator<<(std::ostream& o, |
49 const uint128& b); | 49 const uint128& b); |
50 | 50 |
51 private: | 51 private: |
52 // Little-endian memory order optimizations can benefit from | 52 // Little-endian memory order optimizations can benefit from |
53 // having lo_ first, hi_ last. | 53 // having lo_ first, hi_ last. |
54 // See util/endian/endian.h and Load128/Store128 for storing a uint128. | 54 // See util/endian/endian.h and Load128/Store128 for storing a uint128. |
55 uint64 lo_; | 55 uint64 lo_; |
56 uint64 hi_; | 56 uint64 hi_; |
57 | 57 |
58 // Not implemented, just declared for catching automatic type conversions. | 58 // Not implemented, just declared for catching automatic type conversions. |
59 uint128(uint8); | 59 uint128(uint8); |
60 uint128(uint16); | 60 uint128(uint16); |
61 uint128(float v); | 61 uint128(float v); |
62 uint128(double v); | 62 uint128(double v); |
63 }; | 63 }; |
64 | 64 |
65 // This is a POD form of uint128 which can be used for static variables which | 65 // This is a POD form of uint128 which can be used for static variables which |
66 // need to be operated on as uint128. | 66 // need to be operated on as uint128. |
67 struct uint128_pod { | 67 struct uint128_pod { |
68 // Note: The ordering of fields is different than 'class uint128' but the | 68 // Note: The ordering of fields is different than 'class uint128' but the |
69 // same as its 2-arg constructor. This enables more obvious initialization | 69 // same as its 2-arg constructor. This enables more obvious initialization |
70 // of static instances, which is the primary reason for this struct in the | 70 // of static instances, which is the primary reason for this struct in the |
71 // first place. This does not seem to defeat any optimizations wrt | 71 // first place. This does not seem to defeat any optimizations wrt |
72 // operations involving this struct. | 72 // operations involving this struct. |
73 uint64 hi; | 73 uint64 hi; |
74 uint64 lo; | 74 uint64 lo; |
75 }; | 75 }; |
76 | 76 |
77 NET_EXPORT_PRIVATE extern const uint128_pod kuint128max; | 77 NET_EXPORT_PRIVATE extern const uint128_pod kuint128max; |
78 | 78 |
79 // allow uint128 to be logged | 79 // allow uint128 to be logged |
80 NET_EXPORT_PRIVATE extern std::ostream& operator<<(std::ostream& o, | 80 NET_EXPORT_PRIVATE extern std::ostream& operator<<(std::ostream& o, |
81 const uint128& b); | 81 const uint128& b); |
82 | 82 |
83 // Methods to access low and high pieces of 128-bit value. | 83 // Methods to access low and high pieces of 128-bit value. |
84 // Defined externally from uint128 to facilitate conversion | 84 // Defined externally from uint128 to facilitate conversion |
85 // to native 128-bit types when compilers support them. | 85 // to native 128-bit types when compilers support them. |
86 inline uint64 Uint128Low64(const uint128& v) { return v.lo_; } | 86 inline uint64 Uint128Low64(const uint128& v) { |
87 inline uint64 Uint128High64(const uint128& v) { return v.hi_; } | 87 return v.lo_; |
| 88 } |
| 89 inline uint64 Uint128High64(const uint128& v) { |
| 90 return v.hi_; |
| 91 } |
88 | 92 |
89 // TODO: perhaps it would be nice to have int128, a signed 128-bit type? | 93 // TODO: perhaps it would be nice to have int128, a signed 128-bit type? |
90 | 94 |
91 // -------------------------------------------------------------------------- | 95 // -------------------------------------------------------------------------- |
92 // Implementation details follow | 96 // Implementation details follow |
93 // -------------------------------------------------------------------------- | 97 // -------------------------------------------------------------------------- |
94 inline bool operator==(const uint128& lhs, const uint128& rhs) { | 98 inline bool operator==(const uint128& lhs, const uint128& rhs) { |
95 return (Uint128Low64(lhs) == Uint128Low64(rhs) && | 99 return (Uint128Low64(lhs) == Uint128Low64(rhs) && |
96 Uint128High64(lhs) == Uint128High64(rhs)); | 100 Uint128High64(lhs) == Uint128High64(rhs)); |
97 } | 101 } |
98 inline bool operator!=(const uint128& lhs, const uint128& rhs) { | 102 inline bool operator!=(const uint128& lhs, const uint128& rhs) { |
99 return !(lhs == rhs); | 103 return !(lhs == rhs); |
100 } | 104 } |
101 inline uint128& uint128::operator=(const uint128& b) { | 105 inline uint128& uint128::operator=(const uint128& b) { |
102 lo_ = b.lo_; | 106 lo_ = b.lo_; |
103 hi_ = b.hi_; | 107 hi_ = b.hi_; |
104 return *this; | 108 return *this; |
105 } | 109 } |
106 | 110 |
107 inline uint128::uint128(): lo_(0), hi_(0) { } | 111 inline uint128::uint128() : lo_(0), hi_(0) { |
108 inline uint128::uint128(uint64 top, uint64 bottom) : lo_(bottom), hi_(top) { } | 112 } |
109 inline uint128::uint128(const uint128 &v) : lo_(v.lo_), hi_(v.hi_) { } | 113 inline uint128::uint128(uint64 top, uint64 bottom) : lo_(bottom), hi_(top) { |
110 inline uint128::uint128(const uint128_pod &v) : lo_(v.lo), hi_(v.hi) { } | 114 } |
111 inline uint128::uint128(uint64 bottom) : lo_(bottom), hi_(0) { } | 115 inline uint128::uint128(const uint128& v) : lo_(v.lo_), hi_(v.hi_) { |
112 inline uint128::uint128(uint32 bottom) : lo_(bottom), hi_(0) { } | 116 } |
| 117 inline uint128::uint128(const uint128_pod& v) : lo_(v.lo), hi_(v.hi) { |
| 118 } |
| 119 inline uint128::uint128(uint64 bottom) : lo_(bottom), hi_(0) { |
| 120 } |
| 121 inline uint128::uint128(uint32 bottom) : lo_(bottom), hi_(0) { |
| 122 } |
113 inline uint128::uint128(int bottom) : lo_(bottom), hi_(0) { | 123 inline uint128::uint128(int bottom) : lo_(bottom), hi_(0) { |
114 if (bottom < 0) { | 124 if (bottom < 0) { |
115 --hi_; | 125 --hi_; |
116 } | 126 } |
117 } | 127 } |
118 inline void uint128::Initialize(uint64 top, uint64 bottom) { | 128 inline void uint128::Initialize(uint64 top, uint64 bottom) { |
119 hi_ = top; | 129 hi_ = top; |
120 lo_ = bottom; | 130 lo_ = bottom; |
121 } | 131 } |
122 | 132 |
123 // Comparison operators. | 133 // Comparison operators. |
124 | 134 |
125 #define CMP128(op) \ | 135 #define CMP128(op) \ |
126 inline bool operator op(const uint128& lhs, const uint128& rhs) { \ | 136 inline bool operator op(const uint128& lhs, const uint128& rhs) { \ |
127 return (Uint128High64(lhs) == Uint128High64(rhs)) ? \ | 137 return (Uint128High64(lhs) == Uint128High64(rhs)) \ |
128 (Uint128Low64(lhs) op Uint128Low64(rhs)) : \ | 138 ? (Uint128Low64(lhs) op Uint128Low64(rhs)) \ |
129 (Uint128High64(lhs) op Uint128High64(rhs)); \ | 139 : (Uint128High64(lhs) op Uint128High64(rhs)); \ |
130 } | 140 } |
131 | 141 |
132 CMP128(<) | 142 CMP128(< ) |
133 CMP128(>) | 143 CMP128(> ) |
134 CMP128(>=) | 144 CMP128(>= ) |
135 CMP128(<=) | 145 CMP128(<= ) |
136 | 146 |
137 #undef CMP128 | 147 #undef CMP128 |
138 | 148 |
139 // Unary operators | 149 // Unary operators |
140 | 150 |
141 inline uint128 operator-(const uint128& val) { | 151 inline uint128 operator-(const uint128& val) { |
142 const uint64 hi_flip = ~Uint128High64(val); | 152 const uint64 hi_flip = ~Uint128High64(val); |
143 const uint64 lo_flip = ~Uint128Low64(val); | 153 const uint64 lo_flip = ~Uint128Low64(val); |
144 const uint64 lo_add = lo_flip + 1; | 154 const uint64 lo_add = lo_flip + 1; |
145 if (lo_add < lo_flip) { | 155 if (lo_add < lo_flip) { |
146 return uint128(hi_flip + 1, lo_add); | 156 return uint128(hi_flip + 1, lo_add); |
147 } | 157 } |
148 return uint128(hi_flip, lo_add); | 158 return uint128(hi_flip, lo_add); |
149 } | 159 } |
150 | 160 |
151 inline bool operator!(const uint128& val) { | 161 inline bool operator!(const uint128& val) { |
152 return !Uint128High64(val) && !Uint128Low64(val); | 162 return !Uint128High64(val) && !Uint128Low64(val); |
153 } | 163 } |
154 | 164 |
155 // Logical operators. | 165 // Logical operators. |
156 | 166 |
157 inline uint128 operator~(const uint128& val) { | 167 inline uint128 operator~(const uint128& val) { |
158 return uint128(~Uint128High64(val), ~Uint128Low64(val)); | 168 return uint128(~Uint128High64(val), ~Uint128Low64(val)); |
159 } | 169 } |
160 | 170 |
161 #define LOGIC128(op) \ | 171 #define LOGIC128(op) \ |
162 inline uint128 operator op(const uint128& lhs, const uint128& rhs) { \ | 172 inline uint128 operator op(const uint128& lhs, const uint128& rhs) { \ |
163 return uint128(Uint128High64(lhs) op Uint128High64(rhs), \ | 173 return uint128(Uint128High64(lhs) op Uint128High64(rhs), \ |
164 Uint128Low64(lhs) op Uint128Low64(rhs)); \ | 174 Uint128Low64(lhs) op Uint128Low64(rhs)); \ |
165 } | 175 } |
166 | 176 |
167 LOGIC128(|) | 177 LOGIC128(| ) |
168 LOGIC128(&) | 178 LOGIC128(&) |
169 LOGIC128(^) | 179 LOGIC128 (^) |
170 | 180 |
171 #undef LOGIC128 | 181 #undef LOGIC128 |
172 | 182 |
173 #define LOGICASSIGN128(op) \ | 183 #define LOGICASSIGN128(op) \ |
174 inline uint128& uint128::operator op(const uint128& other) { \ | 184 inline uint128& uint128::operator op(const uint128& other) { \ |
175 hi_ op other.hi_; \ | 185 hi_ op other.hi_; \ |
176 lo_ op other.lo_; \ | 186 lo_ op other.lo_; \ |
177 return *this; \ | 187 return *this; \ |
178 } | 188 } |
179 | 189 |
180 LOGICASSIGN128(|=) | 190 LOGICASSIGN128(|= ) |
181 LOGICASSIGN128(&=) | 191 LOGICASSIGN128(&= ) |
182 LOGICASSIGN128(^=) | 192 LOGICASSIGN128(^= ) |
183 | 193 |
184 #undef LOGICASSIGN128 | 194 #undef LOGICASSIGN128 |
185 | 195 |
186 // Shift operators. | 196 // Shift operators. |
187 | 197 |
188 inline uint128 operator<<(const uint128& val, int amount) { | 198 inline uint128 operator<<(const uint128& val, int amount) { |
189 // uint64 shifts of >= 64 are undefined, so we will need some special-casing. | 199 // uint64 shifts of >= 64 are undefined, so we will need some special-casing. |
190 if (amount < 64) { | 200 if (amount < 64) { |
191 if (amount == 0) { | 201 if (amount == 0) { |
192 return val; | 202 return val; |
193 } | 203 } |
194 uint64 new_hi = (Uint128High64(val) << amount) | | 204 uint64 new_hi = |
195 (Uint128Low64(val) >> (64 - amount)); | 205 (Uint128High64(val) << amount) | (Uint128Low64(val) >> (64 - amount)); |
196 uint64 new_lo = Uint128Low64(val) << amount; | 206 uint64 new_lo = Uint128Low64(val) << amount; |
197 return uint128(new_hi, new_lo); | 207 return uint128(new_hi, new_lo); |
198 } else if (amount < 128) { | 208 } else if (amount < 128) { |
199 return uint128(Uint128Low64(val) << (amount - 64), 0); | 209 return uint128(Uint128Low64(val) << (amount - 64), 0); |
200 } else { | 210 } else { |
201 return uint128(0, 0); | 211 return uint128(0, 0); |
202 } | 212 } |
203 } | 213 } |
204 | 214 |
205 inline uint128 operator>>(const uint128& val, int amount) { | 215 inline uint128 operator>>(const uint128& val, int amount) { |
206 // uint64 shifts of >= 64 are undefined, so we will need some special-casing. | 216 // uint64 shifts of >= 64 are undefined, so we will need some special-casing. |
207 if (amount < 64) { | 217 if (amount < 64) { |
208 if (amount == 0) { | 218 if (amount == 0) { |
209 return val; | 219 return val; |
210 } | 220 } |
211 uint64 new_hi = Uint128High64(val) >> amount; | 221 uint64 new_hi = Uint128High64(val) >> amount; |
212 uint64 new_lo = (Uint128Low64(val) >> amount) | | 222 uint64 new_lo = |
213 (Uint128High64(val) << (64 - amount)); | 223 (Uint128Low64(val) >> amount) | (Uint128High64(val) << (64 - amount)); |
214 return uint128(new_hi, new_lo); | 224 return uint128(new_hi, new_lo); |
215 } else if (amount < 128) { | 225 } else if (amount < 128) { |
216 return uint128(0, Uint128High64(val) >> (amount - 64)); | 226 return uint128(0, Uint128High64(val) >> (amount - 64)); |
217 } else { | 227 } else { |
218 return uint128(0, 0); | 228 return uint128(0, 0); |
219 } | 229 } |
220 } | 230 } |
221 | 231 |
222 inline uint128& uint128::operator<<=(int amount) { | 232 inline uint128& uint128::operator<<=(int amount) { |
223 // uint64 shifts of >= 64 are undefined, so we will need some special-casing. | 233 // uint64 shifts of >= 64 are undefined, so we will need some special-casing. |
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321 *this += 1; | 331 *this += 1; |
322 return *this; | 332 return *this; |
323 } | 333 } |
324 | 334 |
325 inline uint128& uint128::operator--() { | 335 inline uint128& uint128::operator--() { |
326 *this -= 1; | 336 *this -= 1; |
327 return *this; | 337 return *this; |
328 } | 338 } |
329 | 339 |
330 #endif // NET_BASE_INT128_H_ | 340 #endif // NET_BASE_INT128_H_ |
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