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-rw-r--r--src/arith_uint256.cpp357
1 files changed, 357 insertions, 0 deletions
diff --git a/src/arith_uint256.cpp b/src/arith_uint256.cpp
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index 0000000000..0dba429a8d
--- /dev/null
+++ b/src/arith_uint256.cpp
@@ -0,0 +1,357 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2014 The Bitcoin developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include "arith_uint256.h"
+
+#include "utilstrencodings.h"
+
+#include <stdio.h>
+#include <string.h>
+
+template <unsigned int BITS>
+base_uint<BITS>::base_uint(const std::string& str)
+{
+ SetHex(str);
+}
+
+template <unsigned int BITS>
+base_uint<BITS>::base_uint(const std::vector<unsigned char>& vch)
+{
+ if (vch.size() != sizeof(pn))
+ throw uint_error("Converting vector of wrong size to base_uint");
+ memcpy(pn, &vch[0], sizeof(pn));
+}
+
+template <unsigned int BITS>
+base_uint<BITS>& base_uint<BITS>::operator<<=(unsigned int shift)
+{
+ base_uint<BITS> a(*this);
+ for (int i = 0; i < WIDTH; i++)
+ pn[i] = 0;
+ int k = shift / 32;
+ shift = shift % 32;
+ for (int i = 0; i < WIDTH; i++) {
+ if (i + k + 1 < WIDTH && shift != 0)
+ pn[i + k + 1] |= (a.pn[i] >> (32 - shift));
+ if (i + k < WIDTH)
+ pn[i + k] |= (a.pn[i] << shift);
+ }
+ return *this;
+}
+
+template <unsigned int BITS>
+base_uint<BITS>& base_uint<BITS>::operator>>=(unsigned int shift)
+{
+ base_uint<BITS> a(*this);
+ for (int i = 0; i < WIDTH; i++)
+ pn[i] = 0;
+ int k = shift / 32;
+ shift = shift % 32;
+ for (int i = 0; i < WIDTH; i++) {
+ if (i - k - 1 >= 0 && shift != 0)
+ pn[i - k - 1] |= (a.pn[i] << (32 - shift));
+ if (i - k >= 0)
+ pn[i - k] |= (a.pn[i] >> shift);
+ }
+ return *this;
+}
+
+template <unsigned int BITS>
+base_uint<BITS>& base_uint<BITS>::operator*=(uint32_t b32)
+{
+ uint64_t carry = 0;
+ for (int i = 0; i < WIDTH; i++) {
+ uint64_t n = carry + (uint64_t)b32 * pn[i];
+ pn[i] = n & 0xffffffff;
+ carry = n >> 32;
+ }
+ return *this;
+}
+
+template <unsigned int BITS>
+base_uint<BITS>& base_uint<BITS>::operator*=(const base_uint& b)
+{
+ base_uint<BITS> a = *this;
+ *this = 0;
+ for (int j = 0; j < WIDTH; j++) {
+ uint64_t carry = 0;
+ for (int i = 0; i + j < WIDTH; i++) {
+ uint64_t n = carry + pn[i + j] + (uint64_t)a.pn[j] * b.pn[i];
+ pn[i + j] = n & 0xffffffff;
+ carry = n >> 32;
+ }
+ }
+ return *this;
+}
+
+template <unsigned int BITS>
+base_uint<BITS>& base_uint<BITS>::operator/=(const base_uint& b)
+{
+ base_uint<BITS> div = b; // make a copy, so we can shift.
+ base_uint<BITS> num = *this; // make a copy, so we can subtract.
+ *this = 0; // the quotient.
+ int num_bits = num.bits();
+ int div_bits = div.bits();
+ if (div_bits == 0)
+ throw uint_error("Division by zero");
+ if (div_bits > num_bits) // the result is certainly 0.
+ return *this;
+ int shift = num_bits - div_bits;
+ div <<= shift; // shift so that div and num align.
+ while (shift >= 0) {
+ if (num >= div) {
+ num -= div;
+ pn[shift / 32] |= (1 << (shift & 31)); // set a bit of the result.
+ }
+ div >>= 1; // shift back.
+ shift--;
+ }
+ // num now contains the remainder of the division.
+ return *this;
+}
+
+template <unsigned int BITS>
+int base_uint<BITS>::CompareTo(const base_uint<BITS>& b) const
+{
+ for (int i = WIDTH - 1; i >= 0; i--) {
+ if (pn[i] < b.pn[i])
+ return -1;
+ if (pn[i] > b.pn[i])
+ return 1;
+ }
+ return 0;
+}
+
+template <unsigned int BITS>
+bool base_uint<BITS>::EqualTo(uint64_t b) const
+{
+ for (int i = WIDTH - 1; i >= 2; i--) {
+ if (pn[i])
+ return false;
+ }
+ if (pn[1] != (b >> 32))
+ return false;
+ if (pn[0] != (b & 0xfffffffful))
+ return false;
+ return true;
+}
+
+template <unsigned int BITS>
+double base_uint<BITS>::getdouble() const
+{
+ double ret = 0.0;
+ double fact = 1.0;
+ for (int i = 0; i < WIDTH; i++) {
+ ret += fact * pn[i];
+ fact *= 4294967296.0;
+ }
+ return ret;
+}
+
+template <unsigned int BITS>
+std::string base_uint<BITS>::GetHex() const
+{
+ char psz[sizeof(pn) * 2 + 1];
+ for (unsigned int i = 0; i < sizeof(pn); i++)
+ sprintf(psz + i * 2, "%02x", ((unsigned char*)pn)[sizeof(pn) - i - 1]);
+ return std::string(psz, psz + sizeof(pn) * 2);
+}
+
+template <unsigned int BITS>
+void base_uint<BITS>::SetHex(const char* psz)
+{
+ memset(pn, 0, sizeof(pn));
+
+ // skip leading spaces
+ while (isspace(*psz))
+ psz++;
+
+ // skip 0x
+ if (psz[0] == '0' && tolower(psz[1]) == 'x')
+ psz += 2;
+
+ // hex string to uint
+ const char* pbegin = psz;
+ while (::HexDigit(*psz) != -1)
+ psz++;
+ psz--;
+ unsigned char* p1 = (unsigned char*)pn;
+ unsigned char* pend = p1 + WIDTH * 4;
+ while (psz >= pbegin && p1 < pend) {
+ *p1 = ::HexDigit(*psz--);
+ if (psz >= pbegin) {
+ *p1 |= ((unsigned char)::HexDigit(*psz--) << 4);
+ p1++;
+ }
+ }
+}
+
+template <unsigned int BITS>
+void base_uint<BITS>::SetHex(const std::string& str)
+{
+ SetHex(str.c_str());
+}
+
+template <unsigned int BITS>
+std::string base_uint<BITS>::ToString() const
+{
+ return (GetHex());
+}
+
+template <unsigned int BITS>
+unsigned int base_uint<BITS>::bits() const
+{
+ for (int pos = WIDTH - 1; pos >= 0; pos--) {
+ if (pn[pos]) {
+ for (int bits = 31; bits > 0; bits--) {
+ if (pn[pos] & 1 << bits)
+ return 32 * pos + bits + 1;
+ }
+ return 32 * pos + 1;
+ }
+ }
+ return 0;
+}
+
+// Explicit instantiations for base_uint<160>
+template base_uint<160>::base_uint(const std::string&);
+template base_uint<160>::base_uint(const std::vector<unsigned char>&);
+template base_uint<160>& base_uint<160>::operator<<=(unsigned int);
+template base_uint<160>& base_uint<160>::operator>>=(unsigned int);
+template base_uint<160>& base_uint<160>::operator*=(uint32_t b32);
+template base_uint<160>& base_uint<160>::operator*=(const base_uint<160>& b);
+template base_uint<160>& base_uint<160>::operator/=(const base_uint<160>& b);
+template int base_uint<160>::CompareTo(const base_uint<160>&) const;
+template bool base_uint<160>::EqualTo(uint64_t) const;
+template double base_uint<160>::getdouble() const;
+template std::string base_uint<160>::GetHex() const;
+template std::string base_uint<160>::ToString() const;
+template void base_uint<160>::SetHex(const char*);
+template void base_uint<160>::SetHex(const std::string&);
+template unsigned int base_uint<160>::bits() const;
+
+// Explicit instantiations for base_uint<256>
+template base_uint<256>::base_uint(const std::string&);
+template base_uint<256>::base_uint(const std::vector<unsigned char>&);
+template base_uint<256>& base_uint<256>::operator<<=(unsigned int);
+template base_uint<256>& base_uint<256>::operator>>=(unsigned int);
+template base_uint<256>& base_uint<256>::operator*=(uint32_t b32);
+template base_uint<256>& base_uint<256>::operator*=(const base_uint<256>& b);
+template base_uint<256>& base_uint<256>::operator/=(const base_uint<256>& b);
+template int base_uint<256>::CompareTo(const base_uint<256>&) const;
+template bool base_uint<256>::EqualTo(uint64_t) const;
+template double base_uint<256>::getdouble() const;
+template std::string base_uint<256>::GetHex() const;
+template std::string base_uint<256>::ToString() const;
+template void base_uint<256>::SetHex(const char*);
+template void base_uint<256>::SetHex(const std::string&);
+template unsigned int base_uint<256>::bits() const;
+
+// This implementation directly uses shifts instead of going
+// through an intermediate MPI representation.
+arith_uint256& arith_uint256::SetCompact(uint32_t nCompact, bool* pfNegative, bool* pfOverflow)
+{
+ int nSize = nCompact >> 24;
+ uint32_t nWord = nCompact & 0x007fffff;
+ if (nSize <= 3) {
+ nWord >>= 8 * (3 - nSize);
+ *this = nWord;
+ } else {
+ *this = nWord;
+ *this <<= 8 * (nSize - 3);
+ }
+ if (pfNegative)
+ *pfNegative = nWord != 0 && (nCompact & 0x00800000) != 0;
+ if (pfOverflow)
+ *pfOverflow = nWord != 0 && ((nSize > 34) ||
+ (nWord > 0xff && nSize > 33) ||
+ (nWord > 0xffff && nSize > 32));
+ return *this;
+}
+
+uint32_t arith_uint256::GetCompact(bool fNegative) const
+{
+ int nSize = (bits() + 7) / 8;
+ uint32_t nCompact = 0;
+ if (nSize <= 3) {
+ nCompact = GetLow64() << 8 * (3 - nSize);
+ } else {
+ arith_uint256 bn = *this >> 8 * (nSize - 3);
+ nCompact = bn.GetLow64();
+ }
+ // The 0x00800000 bit denotes the sign.
+ // Thus, if it is already set, divide the mantissa by 256 and increase the exponent.
+ if (nCompact & 0x00800000) {
+ nCompact >>= 8;
+ nSize++;
+ }
+ assert((nCompact & ~0x007fffff) == 0);
+ assert(nSize < 256);
+ nCompact |= nSize << 24;
+ nCompact |= (fNegative && (nCompact & 0x007fffff) ? 0x00800000 : 0);
+ return nCompact;
+}
+
+static void inline HashMix(uint32_t& a, uint32_t& b, uint32_t& c)
+{
+ // Taken from lookup3, by Bob Jenkins.
+ a -= c;
+ a ^= ((c << 4) | (c >> 28));
+ c += b;
+ b -= a;
+ b ^= ((a << 6) | (a >> 26));
+ a += c;
+ c -= b;
+ c ^= ((b << 8) | (b >> 24));
+ b += a;
+ a -= c;
+ a ^= ((c << 16) | (c >> 16));
+ c += b;
+ b -= a;
+ b ^= ((a << 19) | (a >> 13));
+ a += c;
+ c -= b;
+ c ^= ((b << 4) | (b >> 28));
+ b += a;
+}
+
+static void inline HashFinal(uint32_t& a, uint32_t& b, uint32_t& c)
+{
+ // Taken from lookup3, by Bob Jenkins.
+ c ^= b;
+ c -= ((b << 14) | (b >> 18));
+ a ^= c;
+ a -= ((c << 11) | (c >> 21));
+ b ^= a;
+ b -= ((a << 25) | (a >> 7));
+ c ^= b;
+ c -= ((b << 16) | (b >> 16));
+ a ^= c;
+ a -= ((c << 4) | (c >> 28));
+ b ^= a;
+ b -= ((a << 14) | (a >> 18));
+ c ^= b;
+ c -= ((b << 24) | (b >> 8));
+}
+
+uint64_t arith_uint256::GetHash(const arith_uint256& salt) const
+{
+ uint32_t a, b, c;
+ a = b = c = 0xdeadbeef + (WIDTH << 2);
+
+ a += pn[0] ^ salt.pn[0];
+ b += pn[1] ^ salt.pn[1];
+ c += pn[2] ^ salt.pn[2];
+ HashMix(a, b, c);
+ a += pn[3] ^ salt.pn[3];
+ b += pn[4] ^ salt.pn[4];
+ c += pn[5] ^ salt.pn[5];
+ HashMix(a, b, c);
+ a += pn[6] ^ salt.pn[6];
+ b += pn[7] ^ salt.pn[7];
+ HashFinal(a, b, c);
+
+ return ((((uint64_t)b) << 32) | c);
+}