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unison/src/simulator/high-precision-double.h
2010-07-09 10:33:35 +02:00

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/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/*
* Copyright (c) 2006 INRIA
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation;
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Author: Mathieu Lacage <mathieu.lacage@sophia.inria.fr>
*/
#ifndef HIGH_PRECISION_DOUBLE_H
#define HIGH_PRECISION_DOUBLE_H
#include <math.h>
namespace ns3 {
/**
* Obviously, this implementation of the HighPrecision class does
* not provide the 128 bits accuracy since it uses a an IEEE754 double
* to store the value. It also does not report overflows.
* So, it is a nice shortcut but in no way a complete solution.
*/
class HighPrecision
{
public:
inline HighPrecision ();
explicit inline HighPrecision (int64_t value, bool dummy);
explicit inline HighPrecision (double value);
inline int64_t GetInteger (void) const;
inline double GetDouble (void) const;
inline void Add (HighPrecision const &o);
inline void Sub (HighPrecision const &o);
inline void Mul (HighPrecision const &o);
inline void Div (HighPrecision const &o);
inline void MulByInvert (const HighPrecision &o);
inline static HighPrecision Invert (uint64_t v);
inline int Compare (HighPrecision const &o) const;
inline static HighPrecision Zero (void);
private:
double m_value;
};
} // namespace ns3
namespace ns3 {
HighPrecision::HighPrecision ()
: m_value (0.0)
{
}
HighPrecision::HighPrecision (int64_t value, bool dummy)
: m_value ((double)value)
{
}
HighPrecision::HighPrecision (double value)
: m_value (value)
{
}
int64_t
HighPrecision::GetInteger (void) const
{
return (int64_t)floor (m_value);
}
double
HighPrecision::GetDouble (void) const
{
return m_value;
}
void
HighPrecision::Add (HighPrecision const &o)
{
m_value += o.m_value;
}
void
HighPrecision::Sub (HighPrecision const &o)
{
m_value -= o.m_value;
}
void
HighPrecision::Mul (HighPrecision const &o)
{
m_value *= o.m_value;
}
void
HighPrecision::Div (HighPrecision const &o)
{
m_value /= o.m_value;
}
void
HighPrecision::MulByInvert (const HighPrecision &o)
{
m_value *= o.m_value;
}
HighPrecision
HighPrecision::Invert (uint64_t v)
{
return HighPrecision (1.0 / v);
}
int
HighPrecision::Compare (HighPrecision const &o) const
{
return (m_value < o.m_value)?-1:(m_value == o.m_value)?0:1;
}
HighPrecision
HighPrecision::Zero (void)
{
return HighPrecision (0,0);
}
} // namespace ns3
#endif /* HIGH_PRECISION_DOUBLE_H */