gnu/lib/libg++/g++-include/Fix24.h

// This may look like C code, but it is really -*- C++ -*-
/*
Copyright (C) 1988 Free Software Foundation
    written by Kurt Baudendistel (gt-eedsp!baud@gatech.edu)
    adapted for libg++ by Doug Lea (dl@rocky.oswego.edu)

This file is part of GNU CC.

GNU CC is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY.  No author or distributor
accepts responsibility to anyone for the consequences of using it
or for whether it serves any particular purpose or works at all,
unless he says so in writing.  Refer to the GNU CC General Public
License for full details.

Everyone is granted permission to copy, modify and redistribute
GNU CC, but only under the conditions described in the
GNU CC General Public License.   A copy of this license is
supposed to have been given to you along with GNU CC so you
can know your rights and responsibilities.  It should be in a
file named COPYING.  Among other things, the copyright notice
and this notice must be preserved on all copies.
*/

#ifndef _Fix24_h
#ifdef __GNUG__
#pragma once
#pragma interface
#endif
#define _Fix24_h 1

#include <stream.h>
#include <std.h>

// extra type definitions

typedef struct {
  long                 u;
  unsigned long        l;
} twolongs;

// constant definitions

static const int
  Fix24_shift = 31;

static const double
  Fix24_fs = 2147483648.,               // 2^Fix24_shift
  Fix24_mult = Fix24_fs,
  Fix24_div = 1./Fix24_fs,
  Fix24_max = 1. - .5/Fix24_fs,
  Fix24_min = -1.;

static const unsigned long
  Fix24_msb = 0x80000000L,
  Fix24_lsb = 0x00000100L,
  Fix24_m_max = 0x7fffff00L,
  Fix24_m_min = 0x80000000L;

static const double
  Fix48_fs = 36028797018963968.,        // 2^(24+Fix24_shift)
  Fix48_max = 1. - .5/Fix48_fs,
  Fix48_min = -1.,
  Fix48_div_u = 1./Fix24_fs,
  Fix48_div_l = 1./Fix48_fs;

static const twolongs
  Fix48_msb = { 0x80000000L, 0L },
  Fix48_lsb = { 0L, 0x00000100L },
  Fix48_m_max = { 0x7fffff00L, 0xffffff00L },
  Fix48_m_min = { 0x80000000L, 0L };

//
// Fix24    class: 24-bit Fixed point data type
//
//      consists of a 24-bit mantissa (sign bit & 23 data bits).
//

class Fix24
{
  friend class          Fix48;

  long                  m;

  long                  assign(double d);
         operator       double();
                        Fix24(long i);
                        Fix24(int i);


public:
                        Fix24();
                        Fix24(Fix24&  f);
                        Fix24(double d);
                        Fix24(Fix48& f);

                        ~Fix24();

  Fix24&                operator=(Fix24&  f);
  Fix24&                operator=(double d);
  Fix24&                operator=(Fix48& f);

  friend long&          mantissa(Fix24&  f);
  friend double         value(Fix24&  f);

  Fix24                 operator +  ();
  Fix24                 operator -  ();

  friend Fix24          operator +  (Fix24&  f, Fix24&  g);
  friend Fix24          operator -  (Fix24&  f, Fix24&  g);
  friend Fix48          operator *  (Fix24&  f, Fix24&  g);
  friend Fix24          operator *  (Fix24&  f, int     g);
  friend Fix24          operator *  (int     g, Fix24&  f);
  friend Fix24          operator /  (Fix24&  f, Fix24&  g);
  friend Fix24          operator << (Fix24&  f, int b);
  friend Fix24          operator >> (Fix24&  f, int b);

  Fix24&                operator += (Fix24&  f);
  Fix24&                operator -= (Fix24&  f);
  Fix24&                operator *= (Fix24&  f);
  Fix24&                operator *= (int     b);
  Fix24&                operator /= (Fix24&  f);

  Fix24&                operator <<=(int b);
  Fix24&                operator >>=(int b);

  friend int            operator == (Fix24&  f, Fix24&  g);
  friend int            operator != (Fix24&  f, Fix24&  g);
  friend int            operator >= (Fix24&  f, Fix24&  g);
  friend int            operator <= (Fix24&  f, Fix24&  g);
  friend int            operator >  (Fix24&  f, Fix24&  g);
  friend int            operator <  (Fix24&  f, Fix24&  g);

  friend istream&       operator >> (istream& s, Fix24&  f);
  friend ostream&       operator << (ostream& s, Fix24&  f);

  void                  overflow(long&);
  void                  range_error(long&);
};


//
// Fix48 class: 48-bit Fixed point data type
//
//      consists of a 48-bit mantissa (sign bit & 47 data bits).
//

class Fix48
{
  friend class         Fix24;

  twolongs             m;

  twolongs             assign(double d);
         operator      double();
                       Fix48(twolongs i);

public:
                       Fix48();
                       Fix48(Fix48& f);
                       Fix48(Fix24&  f);
                       Fix48(double d);
                       ~Fix48();

  Fix48&               operator =  (Fix48& f);
  Fix48&               operator =  (Fix24&  f);
  Fix48&               operator =  (double d);

  friend twolongs&     mantissa(Fix48& f);
  friend double        value(Fix48& f);

  Fix48                operator +  ();
  Fix48                operator -  ();

  friend Fix48         operator +  (Fix48& f, Fix48& g);
  friend Fix48         operator -  (Fix48& f, Fix48& g);
  friend Fix48         operator *  (Fix48& f, int    g);
  friend Fix48         operator *  (int    g, Fix48& f);
  friend Fix48         operator << (Fix48& f, int b);
  friend Fix48         operator >> (Fix48& f, int b);

  friend Fix48         operator *  (Fix24&  f, Fix24&  g);

  Fix48&               operator += (Fix48& f);
  Fix48&               operator -= (Fix48& f);
  Fix48&               operator *= (int    b);
  Fix48&               operator <<=(int b);
  Fix48&               operator >>=(int b);

  friend int           operator == (Fix48& f, Fix48& g);
  friend int           operator != (Fix48& f, Fix48& g);
  friend int           operator >= (Fix48& f, Fix48& g);
  friend int           operator <= (Fix48& f, Fix48& g);
  friend int           operator >  (Fix48& f, Fix48& g);
  friend int           operator <  (Fix48& f, Fix48& g);

  friend istream&      operator >> (istream& s, Fix48& f);
  friend ostream&      operator << (ostream& s, Fix48& f);

  void                 overflow(twolongs& i);
  void                 range_error(twolongs& i);
};


// active error handler declarations

typedef void (*Fix24_peh)(long&);
typedef void (*Fix48_peh)(twolongs&);

extern Fix24_peh Fix24_overflow_handler;
extern Fix48_peh Fix48_overflow_handler;

extern Fix24_peh Fix24_range_error_handler;
extern Fix48_peh Fix48_range_error_handler;


// error handler declarations

#if defined(SHORT_NAMES) || defined(VMS)
#define set_overflow_handler    sohndl
#define set_range_error_handler srnghdl
#endif

extern Fix24_peh set_Fix24_overflow_handler(Fix24_peh);
extern Fix48_peh set_Fix48_overflow_handler(Fix48_peh);
extern void set_overflow_handler(Fix24_peh, Fix48_peh);

extern Fix24_peh set_Fix24_range_error_handler(Fix24_peh);
extern Fix48_peh set_Fix48_range_error_handler(Fix48_peh);
extern void set_range_error_handler(Fix24_peh, Fix48_peh);

extern void
  Fix24_ignore(long&),
  Fix24_overflow_saturate(long&),
  Fix24_overflow_warning_saturate(long&),
  Fix24_warning(long&),
  Fix24_abort(long&);

extern void
  Fix48_ignore(twolongs&),
  Fix48_overflow_saturate(twolongs&),
  Fix48_overflow_warning_saturate(twolongs&),
  Fix48_warning(twolongs&),
  Fix48_abort(twolongs&);

#if defined(__OPTIMIZE__) || defined(USE_LIBGXX_INLINES)

inline Fix24::~Fix24() {}

inline Fix24::Fix24(long i)
{
  m = i;
}

inline Fix24::Fix24(int i)
{
  m = i;
}

inline Fix24::operator double()
{
  return  Fix24_div * m;
}

inline Fix24::Fix24()
{
  m = 0;
}

inline Fix24::Fix24(Fix24&  f)
{
  m = f.m;
}

inline Fix24::Fix24(double d)
{
  m = assign(d);
}

inline Fix24::Fix24(Fix48& f)
{
  m = f.m.u;
}

inline Fix24&  Fix24::operator=(Fix24&  f)
{
  m = f.m;
  return *this;
}

inline Fix24&  Fix24::operator=(double d)
{
  m = assign(d);
  return *this;
}

inline Fix24&  Fix24::operator=(Fix48& f)
{
  m = f.m.u;
  return *this;
}

inline long& mantissa(Fix24&  f)
{
  return f.m;
}

inline double value(Fix24&  f)
{
  return double(f);
}

inline Fix24 Fix24::operator+()
{
  return m;
}

inline Fix24 Fix24::operator-()
{
  return -m;
}

inline Fix24 operator+(Fix24&  f, Fix24&  g)
{
  long sum = f.m + g.m;
  if ( (f.m ^ sum) & (g.m ^ sum) & Fix24_msb )
    f.overflow(sum);
  return sum;
}

inline Fix24 operator-(Fix24&  f, Fix24&  g)
{
  long sum = f.m - g.m;
  if ( (f.m ^ sum) & (-g.m ^ sum) & Fix24_msb )
    f.overflow(sum);
  return sum;
}

inline Fix24 operator*(Fix24& a, int b)
{
  return a.m * b;
}

inline Fix24 operator*(int b, Fix24& a)
{
  return a * b;
}

inline Fix24 operator<<(Fix24& a, int b)
{
  return a.m << b;
}

inline Fix24 operator>>(Fix24& a, int b)
{
  return (a.m >> b) & 0xffffff00L;
}

inline  Fix24&  Fix24:: operator+=(Fix24&  f)
{
  return *this = *this + f;
}

inline Fix24&  Fix24:: operator-=(Fix24&  f)
{
  return *this = *this - f;
}

inline Fix24& Fix24::operator*=(Fix24& f)
{
  return *this = *this * f;
}

inline Fix24&  Fix24:: operator/=(Fix24&  f)
{
  return *this = *this / f;
}

inline Fix24&  Fix24:: operator<<=(int b)
{
  return *this = *this << b;
}

inline Fix24&  Fix24:: operator>>=(int b)
{
  return *this = *this >> b;
}

inline Fix24& Fix24::operator*=(int b)
{
  return *this = *this * b;
}

inline int operator==(Fix24&  f, Fix24&  g)
{
  return f.m == g.m;
}

inline int operator!=(Fix24&  f, Fix24&  g)
{
  return f.m != g.m;
}

inline int operator>=(Fix24&  f, Fix24&  g)
{
  return f.m >= g.m;
}

inline int operator<=(Fix24&  f, Fix24&  g)
{
  return f.m <= g.m;
}

inline int operator>(Fix24&  f, Fix24&  g)
{
  return f.m > g.m;
}

inline int operator<(Fix24&  f, Fix24&  g)
{
  return f.m < g.m;
}

inline istream&  operator>>(istream& s, Fix24&  f)
{
  double d;
  s >> d;
  f = d;
  return s;
}

inline ostream&  operator<<(ostream& s, Fix24&  f)
{
  return s << double(f);
}

inline Fix48::~Fix48() {}

inline Fix48::Fix48(twolongs i)
{
  m = i;
}

inline Fix48:: operator double()
{
/*
 * Note: can't simply do Fix48_div_u * m.u + Fix48_div_l * m.l, because
 * m.u is signed and m.l is unsigned.
 */
  return (m.u >= 0)? Fix48_div_u * m.u + Fix48_div_l * m.l :
      (Fix48_div_u * ((unsigned long)(m.u & 0xffffff00))
          + Fix48_div_l * m.l) - 2;
}

inline Fix48::Fix48()
{
  m.u = 0;
  m.l = 0;
}

inline Fix48::Fix48(Fix48& f)
{
  m = f.m;
}

inline Fix48::Fix48(Fix24&  f)
{
  m.u = f.m;
  m.l = 0;
}

inline Fix48::Fix48(double d)
{
  m = assign(d);
}

inline Fix48& Fix48::operator=(Fix48& f)
{
  m = f.m;
  return *this;
}

inline Fix48& Fix48::operator=(Fix24&  f)
{
  m.u = f.m;
  m.l = 0;
  return *this;
}

inline Fix48& Fix48::operator=(double d)
{
  m = assign(d);
  return *this;
}

inline twolongs& mantissa(Fix48& f)
{
  return f.m;
}

inline double value(Fix48& f)
{
  return double(f);
}

inline Fix48 Fix48::operator+()
{
  return m;
}

inline Fix48 Fix48::operator-()
{
  twolongs n;
  n.l = -m.l;
  n.u = ~m.u + ((n.l ^ m.l) & Fix24_msb ? 0 : Fix24_lsb);
  return Fix48(n);
}

inline Fix48 operator*(int b, Fix48& a)
{
  return a * b;
}

inline Fix48& Fix48::operator+=(Fix48& f)
{
  return *this = *this + f;
}

inline Fix48& Fix48::operator-=(Fix48& f)
{
  return *this = *this - f;
}

inline Fix48& Fix48::operator*=(int b)
{
  return *this = *this * b;
}

inline Fix48& Fix48::operator<<=(int b)
{
  return *this = *this << b;
}

inline Fix48& Fix48::operator>>=(int b)
{
  return *this = *this >> b;
}

inline int operator==(Fix48& f, Fix48& g)
{
  return f.m.u == g.m.u && f.m.l == g.m.l;
}

inline int operator!=(Fix48& f, Fix48& g)
{
  return f.m.u != g.m.u || f.m.l != g.m.l;
}

inline int operator>=(Fix48& f, Fix48& g)
{
  return f.m.u >= g.m.u || (f.m.u == g.m.u && f.m.l >= g.m.l);
}

inline int operator<=(Fix48& f, Fix48& g)
{
  return f.m.u <= g.m.u || (f.m.u == g.m.u && f.m.l <= g.m.l);
}

inline int operator>(Fix48& f, Fix48& g)
{
  return f.m.u > g.m.u || (f.m.u == g.m.u && f.m.l > g.m.l);
}

inline int operator<(Fix48& f, Fix48& g)
{
  return f.m.u < g.m.u || (f.m.u == g.m.u && f.m.l < g.m.l);
}

inline istream& operator>>(istream& s, Fix48& f)
{
  double d;
  s >> d;
  f = d;
  return s;
}

inline ostream& operator<<(ostream& s, Fix48& f)
{
  return s << double(f);
}


#endif
#endif