scfx_rep.h

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  The following code is derived, directly or indirectly, from the SystemC
  source code Copyright (c) 1996-2014 by all Contributors.
  All Rights reserved.

  The contents of this file are subject to the restrictions and limitations
  set forth in the SystemC Open Source License (the "License");
  You may not use this file except in compliance with such restrictions and
  limitations. You may obtain instructions on how to receive a copy of the
  License at http://www.accellera.org/. Software distributed by Contributors
  under the License is distributed on an "AS IS" basis, WITHOUT WARRANTY OF
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 *****************************************************************************/

/*****************************************************************************

  scfx_rep.h - 

  Original Author: Robert Graulich, Synopsys, Inc.
                   Martin Janssen,  Synopsys, Inc.

 *****************************************************************************/

/*****************************************************************************

  MODIFICATION LOG - modifiers, enter your name, affiliation, date and
  changes you are making here.

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// $Log: scfx_rep.h,v $
// Revision 1.6  2011/08/24 22:05:43  acg
//  Torsten Maehne: initialization changes to remove warnings.
//
// Revision 1.5  2011/07/25 10:20:29  acg
//  Andy Goodrich: check in aftermath of call to automake.
//
// Revision 1.4  2010/12/07 20:09:08  acg
// Andy Goodrich: Philipp Hartmann's constructor disambiguation fix
//
// Revision 1.3  2010/08/03 15:54:52  acg
//  Andy Goodrich: formatting.
//
// Revision 1.2  2010/03/15 18:29:01  acg
//  Andy Goodrich: Moved default argument specifications from friend
//  declarations to the actual function signatures.
//
// Revision 1.1.1.1  2006/12/15 20:20:04  acg
// SystemC 2.3
//
// Revision 1.4  2006/03/13 20:24:27  acg
//  Andy Goodrich: Addition of function declarations, e.g., neg_scfx_rep(),
//  to keep gcc 4.x happy.
//
// Revision 1.3  2006/01/13 18:53:58  acg
// Andy Goodrich: added $Log command so that CVS comments are reproduced in
// the source.
//

#ifndef SCFX_REP_H
#define SCFX_REP_H


#include <climits>

#include "sysc/datatypes/fx/scfx_mant.h"
#include "sysc/datatypes/fx/scfx_params.h"
#include "sysc/datatypes/fx/scfx_string.h"


namespace sc_dt
{

// classes defined in this module
class scfx_index;
class scfx_rep;

// forward class declarations
class sc_bv_base;
class sc_signed;
class sc_unsigned;

// function declarations
void multiply( scfx_rep&, const scfx_rep&, const scfx_rep&, 
               int max_wl = SC_DEFAULT_MAX_WL_ );
scfx_rep*  neg_scfx_rep( const scfx_rep& );
scfx_rep*  mult_scfx_rep( const scfx_rep&, const scfx_rep&, 
                          int max_wl = SC_DEFAULT_MAX_WL_ );
scfx_rep*  div_scfx_rep( const scfx_rep&, const scfx_rep&, 
                         int max_wl = SC_DEFAULT_DIV_WL_ );
scfx_rep*  add_scfx_rep( const scfx_rep&, const scfx_rep&, 
                         int max_wl = SC_DEFAULT_MAX_WL_ );
scfx_rep*  sub_scfx_rep( const scfx_rep&, const scfx_rep&, 
                         int max_wl = SC_DEFAULT_MAX_WL_ );
scfx_rep*  lsh_scfx_rep( const scfx_rep&, int );
scfx_rep*  rsh_scfx_rep( const scfx_rep&, int );
int        cmp_scfx_rep( const scfx_rep&, const scfx_rep& );


const int min_mant = 4;

const int bits_in_int  = sizeof(int)  * CHAR_BIT;
const int bits_in_word = sizeof(word) * CHAR_BIT;

// 08/03/2015 GL.
struct scfx_rep_list_lock {
    static pthread_mutex_t m_mutex;
    explicit scfx_rep_list_lock();
    ~scfx_rep_list_lock();
};

// 08/03/2015 GL.
struct scfx_rep_pow10_fx_lock {
    static pthread_mutex_t m_mutex;
    explicit scfx_rep_pow10_fx_lock();
    ~scfx_rep_pow10_fx_lock();
};

// 08/04/2015 GL.
struct scfx_rep_scfx_string_lock {
    static pthread_mutex_t m_mutex;
    explicit scfx_rep_scfx_string_lock();
    ~scfx_rep_scfx_string_lock();
};


// ----------------------------------------------------------------------------
//  CLASS : scfx_index
// ----------------------------------------------------------------------------

class scfx_index
{

public:

    scfx_index( int wi_, int bi_ ) : m_wi( wi_ ), m_bi( bi_ ) {}

    int wi() const { return m_wi; }
    int bi() const { return m_bi; }

    void wi( int wi_ ) { m_wi = wi_; }

private:

    int m_wi;
    int m_bi;

};


// ----------------------------------------------------------------------------
//  CLASS : scfx_rep
//
//  Arbitrary-precision fixed-point implementation class.
// ----------------------------------------------------------------------------

class scfx_rep
{
    enum state
    {
        normal,
        infinity,
        not_a_number
    };

public:

    // constructors

             scfx_rep();
    explicit scfx_rep( int );
    explicit scfx_rep( unsigned int );
    explicit scfx_rep( long );
    explicit scfx_rep( unsigned long );
    explicit scfx_rep( double );
    explicit scfx_rep( const char* );
    explicit scfx_rep( int64 );
    explicit scfx_rep( uint64 );
    explicit scfx_rep( const sc_signed& );
    explicit scfx_rep( const sc_unsigned& );


    // copy constructor

             scfx_rep( const scfx_rep& );


    // destructor

    ~scfx_rep();


    void* operator new( std::size_t );
    void  operator delete( void*, std::size_t );


    void from_string( const char*, int );

    double to_double() const;

    const char* to_string( sc_numrep,
                           int,
                           sc_fmt,
                           const scfx_params* = 0 ) const;


    // assignment operator

    void operator = ( const scfx_rep& );

    friend void multiply( scfx_rep&, const scfx_rep&, const scfx_rep&, int );

    friend scfx_rep* neg_scfx_rep( const scfx_rep& );
    friend scfx_rep* mult_scfx_rep( const scfx_rep&, const scfx_rep&, int );
    friend scfx_rep* div_scfx_rep( const scfx_rep&, const scfx_rep&, int );
    friend scfx_rep* add_scfx_rep( const scfx_rep&, const scfx_rep&, int );
    friend scfx_rep* sub_scfx_rep( const scfx_rep&, const scfx_rep&, int );
    friend scfx_rep* lsh_scfx_rep( const scfx_rep&, int );
    friend scfx_rep* rsh_scfx_rep( const scfx_rep&, int );

    void lshift( int );
    void rshift( int );

    friend int        cmp_scfx_rep( const scfx_rep&, const scfx_rep& );

    void cast( const scfx_params&, bool&, bool& );

    bool is_neg() const;
    bool is_zero() const;
    bool is_nan() const;
    bool is_inf() const;
    bool is_normal() const;

    void set_zero( int = 1 );
    void set_nan();
    void set_inf( int );

    bool   get_bit( int ) const;
    bool   set( int, const scfx_params& );
    bool clear( int, const scfx_params& );

    bool get_slice( int, int, const scfx_params&, sc_bv_base& ) const;
    bool set_slice( int, int, const scfx_params&, const sc_bv_base& );

    void print( ::std::ostream& ) const;
    void dump( ::std::ostream& ) const;

    void get_type( int&, int&, sc_enc& ) const;

    friend scfx_rep* quantization_scfx_rep( const scfx_rep&,
                                             const scfx_params&,
                                             bool& );
    friend scfx_rep*     overflow_scfx_rep( const scfx_rep&,
                                             const scfx_params&,
                                             bool& );

    bool rounding_flag() const;

private:

    friend void  align( const scfx_rep&, const scfx_rep&, int&, int&,
                        scfx_mant_ref&, scfx_mant_ref& );
    friend int   compare_msw( const scfx_rep&, const scfx_rep& );
    friend int   compare_msw_ff( const scfx_rep& lhs, const scfx_rep& rhs );
    unsigned int divide_by_ten();
    int          find_lsw() const;
    int          find_msw() const;
    void         find_sw();
    void         multiply_by_ten();
    void         normalize( int );
    scfx_mant*   resize( int, int ) const;
    void         set_bin( int );
    void         set_oct( int, int );
    void         set_hex( int, int );
    void         shift_left( int );
    void         shift_right( int );

    const scfx_index calc_indices( int ) const;

    void o_extend( const scfx_index&, sc_enc );
    bool o_bit_at( const scfx_index& ) const;
    bool o_zero_left( const scfx_index& ) const;
    bool o_zero_right( const scfx_index& ) const;
    void o_set_low( const scfx_index&, sc_enc );
    void o_set_high( const scfx_index&, const scfx_index&, sc_enc, int = 1 );
    void o_set( const scfx_index&, const scfx_index&, sc_enc, bool );
    void o_invert( const scfx_index& );
    bool q_bit( const scfx_index& ) const;
    void q_clear( const scfx_index& );
    void q_incr( const scfx_index& );
    bool q_odd( const scfx_index& ) const;
    bool q_zero( const scfx_index& ) const;

    void resize_to( int, int = 0 );
    int  size() const;
    void toggle_tc();

    friend void print_dec( scfx_string&, const scfx_rep&, int, sc_fmt );
    friend void print_other( scfx_string&, const scfx_rep&, sc_numrep, int,
                             sc_fmt, const scfx_params* );

    void quantization( const scfx_params&, bool& );
    void     overflow( const scfx_params&, bool& );

    friend int compare_abs( const scfx_rep&, const scfx_rep& );

    void round( int );

private:

    scfx_mant m_mant;     // mantissa (bits of the value).
    int       m_wp;       // index of highest order word in value.
    int       m_sign;     // sign of value.
    state     m_state;    // value state, e.g., normal, inf, etc.
    int       m_msw;      // index of most significant non-zero word.
    int       m_lsw;      // index of least significant non-zero word.
    bool      m_r_flag;   // true if founding occurred.

};


// IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII

inline
void
scfx_rep::set_zero( int sign )
{
    m_mant.clear();
    m_wp = m_msw = m_lsw = 0;
    m_sign = sign;
    m_state = normal;
}

inline
void
scfx_rep::set_nan()
{
    m_mant.resize_to( min_mant );
    m_state = not_a_number;
}

inline
void
scfx_rep::set_inf( int sign )
{
    m_mant.resize_to( min_mant );
    m_state = infinity;
    m_sign = sign;
}


// constructors

inline
scfx_rep::scfx_rep( const char* s )
: m_mant( min_mant ), m_wp( 2 ), m_sign( 1 ), m_state( normal ),
  m_msw(0), m_lsw(0), m_r_flag( false )
{
    from_string( s, SC_DEFAULT_CTE_WL_ );
}


// destructor

inline
scfx_rep::~scfx_rep()
{}


// assignment operator

inline
void
scfx_rep::operator = ( const scfx_rep& f )
{
    if( &f != this )
    {
        m_mant  = f.m_mant;
        m_wp    = f.m_wp;
        m_sign  = f.m_sign;
        m_state = f.m_state;
        m_msw   = f.m_msw;
        m_lsw   = f.m_lsw;
        round( SC_DEFAULT_MAX_WL_ );
    }
}

inline
scfx_rep*
neg_scfx_rep( const scfx_rep& a )
{
    scfx_rep& c = *new scfx_rep( a );
    c.m_sign = - c.m_sign;
    return &c;
}

inline
scfx_rep*
mult_scfx_rep( const scfx_rep& a, const scfx_rep& b, int max_wl )
{
    scfx_rep& c = *new scfx_rep;
    sc_dt::multiply( c, a, b, max_wl );
    return &c;
}

inline
scfx_rep*
lsh_scfx_rep( const scfx_rep& a, int b )
{
    scfx_rep& c = *new scfx_rep( a );
    c.lshift( b );
    return &c;
}

inline
scfx_rep*
rsh_scfx_rep( const scfx_rep& a, int b )
{
    scfx_rep& c = *new scfx_rep( a );
    c.rshift( b );
    return &c;
}

inline
int
scfx_rep::size() const
{
    return m_mant.size();
}

inline
bool
scfx_rep::is_neg() const
{
    return ( m_sign == -1 );
}

inline
bool
scfx_rep::is_zero() const
{
    if( m_state != normal )
        return false;

    for( int i = 0; i < size(); i ++ )
    {
        if( m_mant[i] )
            return false;
    }

    return true;
}

inline
bool
scfx_rep::is_nan() const
{
    return ( m_state == not_a_number );
}

inline
bool
scfx_rep::is_inf() const
{
    return ( m_state == infinity );
}

inline
bool
scfx_rep::is_normal() const
{
    return ( m_state == normal );
}

inline
scfx_rep*
quantization_scfx_rep( const scfx_rep& a,
                        const scfx_params& params,
                        bool& q_flag )
{
    scfx_rep& c = *new scfx_rep( a );
    c.quantization( params, q_flag );
    return &c;
}

inline
scfx_rep*
overflow_scfx_rep( const scfx_rep& a,
                    const scfx_params& params,
                    bool& o_flag )
{
    scfx_rep& c = *new scfx_rep( a );
    c.overflow( params, o_flag );
    return &c;
}

inline
bool
scfx_rep::rounding_flag() const
{
    return m_r_flag;
}

inline
void
scfx_rep::resize_to( int new_size, int restore )
{
    if( restore == -1 )
    {
        int size_incr = new_size - size();
        m_wp += size_incr;
        m_msw += size_incr;
        m_lsw += size_incr;
    }
    m_mant.resize_to( new_size, restore );
}

inline
const scfx_index
scfx_rep::calc_indices( int n ) const
{
    int wi = n / bits_in_word + m_wp;
    int bi = n % bits_in_word;

    if( bi < 0 )
    {
        bi += bits_in_word;
        -- wi;
    }

    return scfx_index( wi, bi );
}

inline
void
scfx_rep::o_extend( const scfx_index& x, sc_enc enc )
{
    int wi = x.wi();
    int bi = x.bi();

    SC_ASSERT_( wi >= 0 && wi < size(), "word index out of range" );
    
    if( enc == SC_US_ || ( m_mant[wi] & ( ((word)1) << bi ) ) == 0 )
    {
        if( bi != bits_in_word - 1 )
            m_mant[wi] &= ~( ((word)-1) << ( bi + 1 ) );
        for( int i = wi + 1; i < size(); ++ i )
            m_mant[i] = 0;
        m_sign = 1;
    }
    else
    {
        if( bi != bits_in_word - 1 )
            m_mant[wi] |= ( ((word)-1) << ( bi + 1 ) );
        for( int i = wi + 1; i < size(); ++ i )
            m_mant[i] = static_cast<word>( -1 );
        m_sign = -1;
    }
}

inline
bool
scfx_rep::o_bit_at( const scfx_index& x ) const
{
    int wi = x.wi();
    int bi = x.bi();
    
    SC_ASSERT_( wi >= 0 && wi < size(), "word index out of range" );

    return ( m_mant[wi] & ( ((word)1) << bi ) ) != 0;
}

inline
bool
scfx_rep::o_zero_left( const scfx_index& x ) const
{
    int wi = x.wi();
    int bi = x.bi();

    SC_ASSERT_( wi >= 0 && wi < size(), "word index out of range" );

    bool zero = true;
    if( bi != bits_in_word - 1 )
        zero = ( m_mant[wi] & ( ((word)-1) << ( bi + 1 ) ) ) == 0;
    for( int i = wi + 1; i < size(); ++ i )
        zero = zero && m_mant[i] == 0;

    return zero;
}

inline
bool
scfx_rep::o_zero_right( const scfx_index& x ) const
{
    int wi = x.wi();
    int bi = x.bi();

    SC_ASSERT_( wi >= 0 && wi < size(), "word index out of range" );

    bool zero = ( m_mant[wi] & ~( ((word)-1) << bi ) ) == 0;
    for( int i = wi - 1; i >= 0; -- i )
        zero = zero && m_mant[i] == 0;

    return zero;
}

inline
void
scfx_rep::o_set_low( const scfx_index& x, sc_enc enc )
{
    int wi = x.wi();
    int bi = x.bi();

    SC_ASSERT_( wi >= 0 && wi < size(), "word index out of range" );

    m_mant.clear();

    if( enc == SC_TC_ )
    {
        m_mant[wi] |= ( ((word)1) << bi );
        m_sign = -1;
    }
    else
        m_sign = 1;
}

inline
void
scfx_rep::o_set_high( const scfx_index& x, const scfx_index& x2,
                      sc_enc enc, int sign )
{
    int wi = x.wi();
    int bi = x.bi();
    int wi2 = x2.wi();
    int bi2 = x2.bi();

    SC_ASSERT_( wi >= 0 && wi < size(), "word index out of range" );
    SC_ASSERT_( wi2 >= 0 && wi2 < size(), "word index out of range" );
    
    int i;

    for( i = 0; i < size(); ++ i )
        m_mant[i] = static_cast<word>( -1 );

    m_mant[wi] &= ~( ((word)-1) << bi );
    for( i = wi + 1; i < size(); ++ i )
        m_mant[i] = 0;

    m_mant[wi2] &= ( ((word)-1) << bi2 );
    for( i = wi2 - 1; i >= 0; -- i )
        m_mant[i] = 0;
    
    if( enc == SC_TC_ )
        m_sign = sign;
    else
    {
        m_mant[wi] |= ( ((word)1) << bi );
        m_sign = 1;
    }
}

inline
void
scfx_rep::o_set( const scfx_index& x, const scfx_index& x3,
                 sc_enc enc, bool under )
{
    int wi = x.wi();
    int bi = x.bi();
    int wi3 = x3.wi();
    int bi3 = x3.bi();
    
    SC_ASSERT_( wi >= 0 && wi < size(), "word index out of range" );
    SC_ASSERT_( wi3 >= 0 && wi3 < size(), "word index out of range" );

    if( bi3 != bits_in_word - 1 )
    {
        if( under )
            m_mant[wi3] &= ~( ((word)-1) << ( bi3 + 1 ) );
        else
            m_mant[wi3] |= ( ((word)-1) << ( bi3 + 1 ) );
    }
    for( int i = wi3 + 1; i < size(); ++ i )
    {
        if( under )
            m_mant[i] = 0;
        else
            m_mant[i] = static_cast<word>( -1 );
    }
        
    if( enc == SC_TC_ )
    {
        if( under )
            m_mant[wi] |= ( ((word)1) << bi );
        else
            m_mant[wi] &= ~( ((word)1) << bi );
    }
}

inline
void
scfx_rep::o_invert( const scfx_index& x2 )
{
    int wi2 = x2.wi();
    int bi2 = x2.bi();

    m_mant[wi2] ^= ( ((word)-1) << bi2 );
    for( int i = wi2 + 1; i < size(); ++ i )
        m_mant[i] = ~ m_mant[i];
}

inline
bool
scfx_rep::q_bit( const scfx_index& x ) const
{
    int wi = x.wi();
    int bi = x.bi();

    SC_ASSERT_( wi >= 0 && wi < size(), "word index out of range" );

    if( bi != 0 )
        return ( m_mant[wi] & ( ((word)1) << ( bi - 1 ) ) ) != 0;
    else if( wi != 0 )
        return ( m_mant[wi - 1] & ( ((word)1) << ( bits_in_word - 1 ) ) ) != 0;
    else
        return false;
}

inline
void
scfx_rep::q_clear( const scfx_index& x )
{
    int wi = x.wi();
    int bi = x.bi();
    
    SC_ASSERT_( wi >= 0 && wi < size(), "word index out of range" );

    m_mant[wi] &= ( ((word)-1) << bi );
    for( int i = wi - 1; i >= 0; -- i )
        m_mant[i] = 0;
}

inline
void
scfx_rep::q_incr( const scfx_index& x )
{
    int wi = x.wi();
    int bi = x.bi();
    
    SC_ASSERT_( wi >= 0 && wi < size(), "word index out of range" );

    word old_val = m_mant[wi];
    m_mant[wi] += ( ((word)1) << bi );
    if( m_mant[wi] <= old_val )
    {
        if( wi + 1 == size() )
          resize_to( size() + 1, 1 );

        for( int i = wi + 1; i < size(); ++ i )
        {
            if( ++ m_mant[i] != 0 )
                break;
        }
    }
}

inline
bool
scfx_rep::q_odd( const scfx_index& x ) const
{
    int wi = x.wi();
    int bi = x.bi();

    SC_ASSERT_( wi >= 0 && wi < size(), "word index out of range" );

    return ( m_mant[wi] & ( ((word)1) << bi ) ) != 0;
}

inline
bool
scfx_rep::q_zero( const scfx_index& x ) const
{
    int wi = x.wi();
    int bi = x.bi();

    SC_ASSERT_( wi >= 0 && wi < size(), "word index out of range" );

    bool zero;

    if( bi != 0 )
    {
        zero = ( m_mant[wi] & ~( ((word)-1) << (bi - 1) ) ) == 0;
        for( int i = wi - 1; i >= 0; -- i )
            zero = zero && m_mant[i] == 0;
    }
    else if( wi != 0 )
    {
        zero = ( m_mant[wi - 1] & ~( ((word)-1) << (bits_in_word - 1) ) ) == 0;
        for( int i = wi - 2; i >= 0; -- i )
            zero = zero && m_mant[i] == 0;
    }
    else
        zero = true;

    return zero;
}

inline
int
scfx_rep::find_lsw() const
{
    for( int i = 0; i < size(); i ++ )
    {
        if( m_mant[i] )
            return i;
    }
    return 0;
}

inline
int
scfx_rep::find_msw() const
{
    for( int i = size() - 1; i >= 0; i -- )
    {
        if( m_mant[i] )
            return i;
    }
    return 0;
}

inline
void
scfx_rep::find_sw()
{
    m_lsw = find_lsw();
    m_msw = find_msw();
}

inline
void
scfx_rep::toggle_tc()
{
    if( is_neg() )
    {
        complement( m_mant, m_mant, m_mant.size() );
        inc( m_mant );
    }
}

} // namespace sc_dt


#endif

// Taf!