X-Git-Url: https://git.ucc.asn.au/?p=ipdf%2Fcode.git;a=blobdiff_plain;f=src%2Farbint.cpp;h=4f8aff2cceea543c05740863e48ecef5c516ed9c;hp=ccde0dd75f54363d90c4e1a0e9ad104fbdc6402a;hb=ee5287fabfb214e8f7b483cde424108270525fd7;hpb=35e78b378435e37ffdb6e53a97f6fa0998999f67

diff --git a/src/arbint.cpp b/src/arbint.cpp
index ccde0dd..4f8aff2 100644
--- a/src/arbint.cpp
+++ b/src/arbint.cpp
@@ -1,52 +1,190 @@
 #include "arbint.h"
 #include <algorithm>
 #include <cstring>
+
+
+#include <string>
+#include <iomanip>
+#include <sstream>
+#include <cstdarg>
+
 using namespace std;
 
-/*
-static bool addc(uint32_t a, uint32_t b, uint32_t * r)
+namespace IPDF
+{
+
+Arbint::Arbint(digit_t i) : m_digits(1), m_sign(i < 0)
 {
-	volatile uint32_t carry = false;
-	volatile uint32_t result = a + b;
-	asm volatile
-	(
-		"jc 1f;"
-		"mov $0, %%eax;"
-		"1:"
-		: "=a" (carry)
-	);
-	*r = result;	
-	return (carry == 1);
+	m_digits[0] = i;
 }
-*/
 
-namespace IPDF
+Arbint::Arbint(unsigned n, digit_t d0, ...) : m_digits(n), m_sign(false)
+{
+	va_list ap;
+	va_start(ap, d0);
+	if (n > 1)
+		m_digits[0] = d0;
+	for (unsigned i = 1; i < n; ++i)
+	{
+		m_digits[i] = va_arg(ap, digit_t);
+	}
+	va_end(ap);
+}
+
+Arbint::Arbint(const Arbint & cpy) : m_digits(cpy.m_digits.size()), m_sign(cpy.m_sign)
+{
+	memcpy(m_digits.data(), cpy.m_digits.data(), 
+		sizeof(digit_t)*m_digits.size());
+}
+
+Arbint & Arbint::operator=(const Arbint & cpy)
+{
+	memmove(m_digits.data(), cpy.m_digits.data(), 
+		sizeof(digit_t)*min(m_digits.size(), cpy.m_digits.size()));
+	if (cpy.m_digits.size() > m_digits.size())
+	{
+		unsigned old_size = m_digits.size();
+		m_digits.resize(cpy.m_digits.size());
+		memset(m_digits.data()+old_size, 0, sizeof(digit_t)*m_digits.size()-old_size);
+	}
+	return *this;
+}
+
+void Arbint::Zero()
+{
+	memset(m_digits.data(), 0, sizeof(digit_t)*m_digits.size());
+}
+
+unsigned Arbint::Shrink()
+{
+	if (m_digits.size() <= 1)
+		return 0;
+	unsigned i;
+	for (i = m_digits.size()-1; (i > 0 && m_digits[i] != 0L); --i);
+	unsigned result = m_digits.size() - i;
+	m_digits.resize(i);
+	return result;
+}
+
+Arbint & Arbint::operator+=(const Arbint & add)
+{
+	if (m_sign == add.m_sign)
+	{
+		// -a + -b == -(a + b)
+		return AddBasic(add);
+	}
+	
+	if (m_sign)
+	{
+		// -a + b == -(a - b)
+		m_sign = false;
+		SubBasic(add);
+		m_sign = !m_sign;
+	}
+	else
+	{
+		// a + -b == a - b
+		SubBasic(add);
+	}
+	return *this;
+}
+
+Arbint & Arbint::operator-=(const Arbint & sub)
 {
+	if (m_sign == sub.m_sign)
+		return SubBasic(sub);
+	return AddBasic(sub);
+}
 
-Arbint::Arbint(int64_t i) : m_words(2), m_sign(false)
+Arbint & Arbint::AddBasic(const Arbint & add)
 {
-	m_sign = i < 0;
-	memcpy(m_words.data(), &i, sizeof(int64_t));
+	if (add.m_digits.size() >= m_digits.size())
+	{
+		m_digits.resize(add.m_digits.size()+1,0L);
+	}
+	
+	digit_t carry = add_digits((digit_t*)m_digits.data(), 
+			(digit_t*)add.m_digits.data(), add.m_digits.size());
+	if (carry != 0L)
+		m_digits[m_digits.size()-1] = carry;
+	else if (m_digits.back() == 0L)
+		m_digits.resize(m_digits.size()-1);
+	return *this;
 }
 
-string Arbint::Str() const
+Arbint & Arbint::SubBasic(const Arbint & sub)
+{
+	if (sub.m_digits.size() >= m_digits.size())
+	{
+		m_digits.resize(sub.m_digits.size(),0L);
+	}
+	digit_t borrow = sub_digits((digit_t*)m_digits.data(), 
+			(digit_t*)sub.m_digits.data(), sub.m_digits.size());
+		
+		
+	//TODO: Write ASM to do this bit?
+	if (borrow != 0L)
+	{
+		m_sign = !m_sign;
+		for (unsigned i = 0; i < m_digits.size(); ++i)
+			m_digits[i] = -m_digits[i];
+	}
+	return *this;
+	return *this;
+}
+
+
+string Arbint::Str(const string & base) const
 {
 	string s("");
-	for (unsigned i = 0; i < m_words.size(); ++i)
+	for (unsigned i = 0; i < m_digits.size(); ++i)
 	{
-		uint32_t w = m_words[i];
+		digit_t w = m_digits[i];
 		do
 		{
-			uint32_t q = w % 10;
+			digit_t q = w % 10;
 			w /= 10;
 			s += ('0' + q);
 		}
 		while (w > 0);
-		if (i+1 < m_words.size()) s += ",";	
+		if (i+1 < m_digits.size()) s += ",";	
 	}
-	if (m_sign) s += '-';
 	reverse(s.begin(), s.end());
 	return s;
 }
 
+bool Arbint::operator==(const Arbint & equ) const
+{
+	if (m_sign != equ.m_sign) return false;
+	unsigned min_size = m_digits.size();
+	const Arbint * larger = &equ;
+	if (m_digits.size() > equ.m_digits.size())
+	{
+		min_size = equ.m_digits.size();
+		larger = this;
+	}
+	
+	if (memcmp(m_digits.data(), equ.m_digits.data(), min_size) != 0)
+		return false;
+	
+	for (unsigned i = min_size; i < larger->m_digits.size(); ++i)
+	{
+		if (larger->m_digits[i] != 0L)
+			return false;
+	}
+	return true;
+}
+
+string Arbint::DigitStr() const
+{
+	stringstream ss("");
+	//ss << std::hex << std::setfill('0');
+	for (unsigned i = 0; i < m_digits.size(); ++i)
+	{
+		if (i != 0) ss << ',';
+		ss << std::setw(2*sizeof(digit_t)) << static_cast<digit_t>(m_digits[i]);
+	}
+	return ss.str();
+}
+
 }