int64x64-128.h

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/*
 * Copyright (c) 2010 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
 *
 */
 
#include "ns3/core-config.h"
 
#if !defined(INT64X64_128_H) && defined(INT64X64_USE_128) && !defined(PYTHON_SCAN)
#define INT64X64_128_H
 
#include <cmath> // pow
#include <stdint.h>
 
#if defined(HAVE___UINT128_T) && !defined(HAVE_UINT128_T)
typedef __uint128_t uint128_t;
typedef __int128_t int128_t;
#endif
 
namespace ns3
{
 
class int64x64_t
{
    static const uint128_t HP128_MASK_HI_BIT = (((int128_t)1) << 127);
    static const uint64_t HP_MASK_LO = 0xffffffffffffffffULL;
    static const uint64_t HP_MASK_HI = ~HP_MASK_LO;
#define HP_MAX_64 (std::pow(2.0L, 64))
 
  public:
    enum impl_type
    {
        int128_impl, 
        cairo_impl,  
        ld_impl,     
    };
 
    static const enum impl_type implementation = int128_impl;
 
    inline int64x64_t()
        : _v(0)
    {
    }
 
    inline int64x64_t(const double value)
    {
        const int64x64_t tmp((long double)value);
        _v = tmp._v;
    }
 
    inline int64x64_t(const long double value)
    {
        const bool negative = value < 0;
        const long double v = negative ? -value : value;
 
        long double fhi;
        long double flo = std::modf(v, &fhi);
        // Add 0.5 to round, which improves the last count
        // This breaks these tests:
        //   TestSuite devices-mesh-dot11s-regression
        //   TestSuite devices-mesh-flame-regression
        //   TestSuite routing-aodv-regression
        //   TestSuite routing-olsr-regression
        // Setting round = 0; breaks:
        //   TestSuite int64x64
        const long double round = 0.5;
        flo = flo * HP_MAX_64 + round;
        int128_t hi = fhi;
        const uint64_t lo = flo;
        if (flo >= HP_MAX_64)
        {
            // conversion to uint64 rolled over
            ++hi;
        }
        _v = hi << 64;
        _v |= lo;
        _v = negative ? -_v : _v;
    }
 
    inline int64x64_t(const int v)
        : _v(v)
    {
        _v <<= 64;
    }
 
    inline int64x64_t(const long int v)
        : _v(v)
    {
        _v <<= 64;
    }
 
    inline int64x64_t(const long long int v)
        : _v(v)
    {
        _v <<= 64;
    }
 
    inline int64x64_t(const unsigned int v)
        : _v(v)
    {
        _v <<= 64;
    }
 
    inline int64x64_t(const unsigned long int v)
        : _v(v)
    {
        _v <<= 64;
    }
 
    inline int64x64_t(const unsigned long long int v)
        : _v(v)
    {
        _v <<= 64;
    }
 
    inline int64x64_t(const int128_t v)
        : _v(v)
    {
    }
 
    explicit inline int64x64_t(const int64_t hi, const uint64_t lo)
    {
        _v = (int128_t)hi << 64;
        _v |= lo;
    }
 
    inline int64x64_t(const int64x64_t& o)
        : _v(o._v)
    {
    }
 
    inline int64x64_t& operator=(const int64x64_t& o)
    {
        _v = o._v;
        return *this;
    }
 
    inline explicit operator bool() const
    {
        return (_v != 0);
    }
 
    inline double GetDouble() const
    {
        const bool negative = _v < 0;
        const uint128_t value = negative ? -_v : _v;
        const long double fhi = value >> 64;
        const long double flo = (value & HP_MASK_LO) / HP_MAX_64;
        long double retval = fhi;
        retval += flo;
        retval = negative ? -retval : retval;
        return retval;
    }
 
    inline int64_t GetHigh() const
    {
        const int128_t retval = _v >> 64;
        return retval;
    }
 
    inline uint64_t GetLow() const
    {
        const uint128_t retval = _v & HP_MASK_LO;
        return retval;
    }
 
    int64_t GetInt() const
    {
        const bool negative = _v < 0;
        const uint128_t value = negative ? -_v : _v;
        int64_t retval = value >> 64;
        retval = negative ? -retval : retval;
        return retval;
    }
 
    int64_t Round() const
    {
        const bool negative = _v < 0;
        int64x64_t value = (negative ? -(*this) : *this);
        const int64x64_t half(0, 1LL << 63);
        value += half;
        int64_t retval = value.GetHigh();
        retval = negative ? -retval : retval;
        return retval;
    }
 
    void MulByInvert(const int64x64_t& o);
 
    static int64x64_t Invert(const uint64_t v);
 
  private:
    friend inline bool operator==(const int64x64_t& lhs, const int64x64_t& rhs)
    {
        return lhs._v == rhs._v;
    }
 
    friend inline bool operator<(const int64x64_t& lhs, const int64x64_t& rhs)
    {
        return lhs._v < rhs._v;
    }
 
    friend inline bool operator>(const int64x64_t& lhs, const int64x64_t& rhs)
    {
        return lhs._v > rhs._v;
    }
 
    friend inline int64x64_t& operator+=(int64x64_t& lhs, const int64x64_t& rhs)
    {
        lhs._v += rhs._v;
        return lhs;
    }
 
    friend inline int64x64_t& operator-=(int64x64_t& lhs, const int64x64_t& rhs)
    {
        lhs._v -= rhs._v;
        return lhs;
    }
 
    friend inline int64x64_t& operator*=(int64x64_t& lhs, const int64x64_t& rhs)
    {
        lhs.Mul(rhs);
        return lhs;
    }
 
    friend inline int64x64_t& operator/=(int64x64_t& lhs, const int64x64_t& rhs)
    {
        lhs.Div(rhs);
        return lhs;
    }
 
    friend inline int64x64_t operator+(const int64x64_t& lhs)
    {
        return lhs;
    }
 
    friend inline int64x64_t operator-(const int64x64_t& lhs)
    {
        return int64x64_t(-lhs._v);
    }
 
    friend inline int64x64_t operator!(const int64x64_t& lhs)
    {
        return int64x64_t(!lhs._v);
    }
 
    void Mul(const int64x64_t& o);
    void Div(const int64x64_t& o);
    static uint128_t Umul(const uint128_t a, const uint128_t b);
    static uint128_t Udiv(const uint128_t a, const uint128_t b);
    static uint128_t UmulByInvert(const uint128_t a, const uint128_t b);
 
    int128_t _v; 
 
}; // class int64x64_t
 
} // namespace ns3
 
#endif /* INT64X64_128_H */