#ifndef BigInteger_h
#define BigInteger_h
#include <wtf/MathExtras.h>
namespace JSC {
class BigInteger {
public:
BigInteger(double number)
{
ASSERT(isfinite(number) && !signbit(number));
ASSERT(number == floor(number));
bool sign;
int32_t exponent;
uint64_t mantissa;
decomposeDouble(number, sign, exponent, mantissa);
ASSERT(!sign && exponent >= 0);
int32_t zeroBits = exponent - 52;
if (zeroBits < 0) {
mantissa >>= -zeroBits;
zeroBits = 0;
}
while (zeroBits >= 32) {
m_values.append(0);
zeroBits -= 32;
}
uint32_t values[3];
values[0] = static_cast<uint32_t>(mantissa);
values[1] = static_cast<uint32_t>(mantissa >> 32);
values[2] = 0;
if (zeroBits) {
values[2] = values[1] >> (32 - zeroBits);
values[1] = (values[1] << zeroBits) | (values[0] >> (32 - zeroBits));
values[0] = (values[0] << zeroBits);
}
m_values.append(values[0]);
m_values.append(values[1]);
m_values.append(values[2]);
while (m_values.size() && !m_values.last())
m_values.removeLast();
}
uint32_t divide(uint32_t divisor)
{
uint32_t carry = 0;
for (size_t i = m_values.size(); i; ) {
--i;
uint64_t dividend = (static_cast<uint64_t>(carry) << 32) + static_cast<uint64_t>(m_values[i]);
uint64_t result = dividend / static_cast<uint64_t>(divisor);
ASSERT(result == static_cast<uint32_t>(result));
uint64_t remainder = dividend % static_cast<uint64_t>(divisor);
ASSERT(remainder == static_cast<uint32_t>(remainder));
m_values[i] = static_cast<uint32_t>(result);
carry = static_cast<uint32_t>(remainder);
}
while (m_values.size() && !m_values.last())
m_values.removeLast();
return carry;
}
bool operator!() { return !m_values.size(); }
private:
Vector<uint32_t, 36> m_values;
};
}
#endif