Bitcoin Core 28.99.0
P2P Digital Currency
arith_uint256.h
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1// Copyright (c) 2009-2010 Satoshi Nakamoto
2// Copyright (c) 2009-2022 The Bitcoin Core developers
3// Distributed under the MIT software license, see the accompanying
4// file COPYING or http://www.opensource.org/licenses/mit-license.php.
5
6#ifndef BITCOIN_ARITH_UINT256_H
7#define BITCOIN_ARITH_UINT256_H
8
9#include <cstdint>
10#include <cstring>
11#include <limits>
12#include <stdexcept>
13#include <string>
14
15class uint256;
16
17class uint_error : public std::runtime_error {
18public:
19 explicit uint_error(const std::string& str) : std::runtime_error(str) {}
20};
21
23template<unsigned int BITS>
25{
26protected:
27 static_assert(BITS / 32 > 0 && BITS % 32 == 0, "Template parameter BITS must be a positive multiple of 32.");
28 static constexpr int WIDTH = BITS / 32;
30 uint32_t pn[WIDTH];
31public:
32
34 {
35 for (int i = 0; i < WIDTH; i++)
36 pn[i] = 0;
37 }
38
40 {
41 for (int i = 0; i < WIDTH; i++)
42 pn[i] = b.pn[i];
43 }
44
46 {
47 if (this != &b) {
48 for (int i = 0; i < WIDTH; i++)
49 pn[i] = b.pn[i];
50 }
51 return *this;
52 }
53
54 base_uint(uint64_t b)
55 {
56 pn[0] = (unsigned int)b;
57 pn[1] = (unsigned int)(b >> 32);
58 for (int i = 2; i < WIDTH; i++)
59 pn[i] = 0;
60 }
61
63 {
65 for (int i = 0; i < WIDTH; i++)
66 ret.pn[i] = ~pn[i];
67 return ret;
68 }
69
71 {
73 for (int i = 0; i < WIDTH; i++)
74 ret.pn[i] = ~pn[i];
75 ++ret;
76 return ret;
77 }
78
79 double getdouble() const;
80
81 base_uint& operator=(uint64_t b)
82 {
83 pn[0] = (unsigned int)b;
84 pn[1] = (unsigned int)(b >> 32);
85 for (int i = 2; i < WIDTH; i++)
86 pn[i] = 0;
87 return *this;
88 }
89
91 {
92 for (int i = 0; i < WIDTH; i++)
93 pn[i] ^= b.pn[i];
94 return *this;
95 }
96
98 {
99 for (int i = 0; i < WIDTH; i++)
100 pn[i] &= b.pn[i];
101 return *this;
102 }
103
105 {
106 for (int i = 0; i < WIDTH; i++)
107 pn[i] |= b.pn[i];
108 return *this;
109 }
110
112 {
113 pn[0] ^= (unsigned int)b;
114 pn[1] ^= (unsigned int)(b >> 32);
115 return *this;
116 }
117
119 {
120 pn[0] |= (unsigned int)b;
121 pn[1] |= (unsigned int)(b >> 32);
122 return *this;
123 }
124
125 base_uint& operator<<=(unsigned int shift);
126 base_uint& operator>>=(unsigned int shift);
127
129 {
130 uint64_t carry = 0;
131 for (int i = 0; i < WIDTH; i++)
132 {
133 uint64_t n = carry + pn[i] + b.pn[i];
134 pn[i] = n & 0xffffffff;
135 carry = n >> 32;
136 }
137 return *this;
138 }
139
141 {
142 *this += -b;
143 return *this;
144 }
145
146 base_uint& operator+=(uint64_t b64)
147 {
148 base_uint b;
149 b = b64;
150 *this += b;
151 return *this;
152 }
153
154 base_uint& operator-=(uint64_t b64)
155 {
156 base_uint b;
157 b = b64;
158 *this += -b;
159 return *this;
160 }
161
162 base_uint& operator*=(uint32_t b32);
163 base_uint& operator*=(const base_uint& b);
164 base_uint& operator/=(const base_uint& b);
165
167 {
168 // prefix operator
169 int i = 0;
170 while (i < WIDTH && ++pn[i] == 0)
171 i++;
172 return *this;
173 }
174
176 {
177 // postfix operator
178 const base_uint ret = *this;
179 ++(*this);
180 return ret;
181 }
182
184 {
185 // prefix operator
186 int i = 0;
187 while (i < WIDTH && --pn[i] == std::numeric_limits<uint32_t>::max())
188 i++;
189 return *this;
190 }
191
193 {
194 // postfix operator
195 const base_uint ret = *this;
196 --(*this);
197 return ret;
198 }
199
201 int CompareTo(const base_uint& b) const;
202 bool EqualTo(uint64_t b) const;
203
204 friend inline base_uint operator+(const base_uint& a, const base_uint& b) { return base_uint(a) += b; }
205 friend inline base_uint operator-(const base_uint& a, const base_uint& b) { return base_uint(a) -= b; }
206 friend inline base_uint operator*(const base_uint& a, const base_uint& b) { return base_uint(a) *= b; }
207 friend inline base_uint operator/(const base_uint& a, const base_uint& b) { return base_uint(a) /= b; }
208 friend inline base_uint operator|(const base_uint& a, const base_uint& b) { return base_uint(a) |= b; }
209 friend inline base_uint operator&(const base_uint& a, const base_uint& b) { return base_uint(a) &= b; }
210 friend inline base_uint operator^(const base_uint& a, const base_uint& b) { return base_uint(a) ^= b; }
211 friend inline base_uint operator>>(const base_uint& a, int shift) { return base_uint(a) >>= shift; }
212 friend inline base_uint operator<<(const base_uint& a, int shift) { return base_uint(a) <<= shift; }
213 friend inline base_uint operator*(const base_uint& a, uint32_t b) { return base_uint(a) *= b; }
214 friend inline bool operator==(const base_uint& a, const base_uint& b) { return memcmp(a.pn, b.pn, sizeof(a.pn)) == 0; }
215 friend inline bool operator!=(const base_uint& a, const base_uint& b) { return memcmp(a.pn, b.pn, sizeof(a.pn)) != 0; }
216 friend inline bool operator>(const base_uint& a, const base_uint& b) { return a.CompareTo(b) > 0; }
217 friend inline bool operator<(const base_uint& a, const base_uint& b) { return a.CompareTo(b) < 0; }
218 friend inline bool operator>=(const base_uint& a, const base_uint& b) { return a.CompareTo(b) >= 0; }
219 friend inline bool operator<=(const base_uint& a, const base_uint& b) { return a.CompareTo(b) <= 0; }
220 friend inline bool operator==(const base_uint& a, uint64_t b) { return a.EqualTo(b); }
221 friend inline bool operator!=(const base_uint& a, uint64_t b) { return !a.EqualTo(b); }
222
224 std::string GetHex() const;
225 std::string ToString() const;
226
227 unsigned int size() const
228 {
229 return sizeof(pn);
230 }
231
236 unsigned int bits() const;
237
238 uint64_t GetLow64() const
239 {
240 static_assert(WIDTH >= 2, "Assertion WIDTH >= 2 failed (WIDTH = BITS / 32). BITS is a template parameter.");
241 return pn[0] | (uint64_t)pn[1] << 32;
242 }
243};
244
246class arith_uint256 : public base_uint<256> {
247public:
248 arith_uint256() = default;
250 arith_uint256(uint64_t b) : base_uint<256>(b) {}
251
272 arith_uint256& SetCompact(uint32_t nCompact, bool *pfNegative = nullptr, bool *pfOverflow = nullptr);
273 uint32_t GetCompact(bool fNegative = false) const;
274
275 friend uint256 ArithToUint256(const arith_uint256 &);
276 friend arith_uint256 UintToArith256(const uint256 &);
277};
278
281
282extern template class base_uint<256>;
283
284#endif // BITCOIN_ARITH_UINT256_H
arith_uint256 UintToArith256(const uint256 &)
uint256 ArithToUint256(const arith_uint256 &)
int ret
256-bit unsigned big integer.
arith_uint256 & SetCompact(uint32_t nCompact, bool *pfNegative=nullptr, bool *pfOverflow=nullptr)
The "compact" format is a representation of a whole number N using an unsigned 32bit number similar t...
uint32_t GetCompact(bool fNegative=false) const
arith_uint256()=default
arith_uint256(uint64_t b)
arith_uint256(const base_uint< 256 > &b)
friend arith_uint256 UintToArith256(const uint256 &)
friend uint256 ArithToUint256(const arith_uint256 &)
Template base class for unsigned big integers.
Definition: arith_uint256.h:25
base_uint operator~() const
Definition: arith_uint256.h:62
uint32_t pn[WIDTH]
Big integer represented with 32-bit digits, least-significant first.
Definition: arith_uint256.h:30
int CompareTo(const base_uint &b) const
Numeric ordering (unlike base_blob::Compare)
base_uint operator--(int)
unsigned int size() const
base_uint(uint64_t b)
Definition: arith_uint256.h:54
base_uint & operator^=(const base_uint &b)
Definition: arith_uint256.h:90
friend bool operator!=(const base_uint &a, const base_uint &b)
base_uint & operator|=(uint64_t b)
base_uint & operator+=(uint64_t b64)
base_uint & operator>>=(unsigned int shift)
base_uint & operator++()
base_uint & operator--()
base_uint & operator=(uint64_t b)
Definition: arith_uint256.h:81
friend base_uint operator-(const base_uint &a, const base_uint &b)
base_uint(const base_uint &b)
Definition: arith_uint256.h:39
friend base_uint operator*(const base_uint &a, const base_uint &b)
static constexpr int WIDTH
Definition: arith_uint256.h:28
friend base_uint operator<<(const base_uint &a, int shift)
base_uint & operator|=(const base_uint &b)
friend base_uint operator&(const base_uint &a, const base_uint &b)
friend bool operator<(const base_uint &a, const base_uint &b)
base_uint & operator-=(uint64_t b64)
friend bool operator==(const base_uint &a, uint64_t b)
base_uint & operator^=(uint64_t b)
base_uint operator-() const
Definition: arith_uint256.h:70
friend base_uint operator>>(const base_uint &a, int shift)
friend bool operator>=(const base_uint &a, const base_uint &b)
base_uint & operator*=(uint32_t b32)
friend base_uint operator|(const base_uint &a, const base_uint &b)
bool EqualTo(uint64_t b) const
friend base_uint operator*(const base_uint &a, uint32_t b)
base_uint & operator&=(const base_uint &b)
Definition: arith_uint256.h:97
friend bool operator==(const base_uint &a, const base_uint &b)
friend bool operator!=(const base_uint &a, uint64_t b)
friend base_uint operator/(const base_uint &a, const base_uint &b)
friend base_uint operator^(const base_uint &a, const base_uint &b)
friend bool operator>(const base_uint &a, const base_uint &b)
friend bool operator<=(const base_uint &a, const base_uint &b)
double getdouble() const
base_uint & operator<<=(unsigned int shift)
std::string ToString() const
base_uint operator++(int)
base_uint & operator/=(const base_uint &b)
base_uint & operator+=(const base_uint &b)
uint64_t GetLow64() const
base_uint & operator=(const base_uint &b)
Definition: arith_uint256.h:45
std::string GetHex() const
Hex encoding of the number (with the most significant digits first).
base_uint & operator-=(const base_uint &b)
friend base_uint operator+(const base_uint &a, const base_uint &b)
unsigned int bits() const
Returns the position of the highest bit set plus one, or zero if the value is zero.
256-bit opaque blob.
Definition: uint256.h:201
uint_error(const std::string &str)
Definition: arith_uint256.h:19