datatypes/bit/sc_bv_base.cpp

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

  sc_bv_base.cpp -- Arbitrary size bit vector class.

  Original Author: Gene Bushuyev, Synopsys, Inc.

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

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

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

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// $Log: sc_bv_base.cpp,v $
// Revision 1.2  2011/08/24 22:05:40  acg
//  Torsten Maehne: initialization changes to remove warnings.
//
// Revision 1.1.1.1  2006/12/15 20:20:04  acg
// SystemC 2.3
//
// Revision 1.4  2006/04/11 23:12:26  acg
//   Andy Goodrich: Fixed bug in parsing of extended string constants like
//   0bus1110011.
//
// Revision 1.3  2006/01/13 18:53:53  acg
// Andy Goodrich: added $Log command so that CVS comments are reproduced in
// the source.
//

#include <string.h>

#include "sysc/datatypes/bit/sc_bit_ids.h"
#include "sysc/datatypes/bit/sc_bv_base.h"
#include "sysc/datatypes/fx/sc_fix.h"
#include "sysc/datatypes/fx/sc_ufix.h"


namespace sc_dt
{

// ----------------------------------------------------------------------------
//  CLASS : sc_bv_base
//
//  Arbitrary size bit vector base class.
// ----------------------------------------------------------------------------

void
sc_bv_base::init( int length_, bool init_value )
{
    // check the length
    if( length_ <= 0 ) {
	SC_REPORT_ERROR( sc_core::SC_ID_ZERO_LENGTH_, 0 );
    }
    // allocate memory for the data and control words
    m_len = length_;
    m_size = (m_len - 1) / SC_DIGIT_SIZE + 1;
    m_data = new sc_digit[m_size];
    // initialize the bits to 'init_value'
    sc_digit dw = init_value ? ~SC_DIGIT_ZERO : SC_DIGIT_ZERO;
    int sz = m_size;
    for( int i = 0; i < sz; ++ i ) {
	m_data[i] = dw;
    }
    clean_tail();
}


void
sc_bv_base::assign_from_string( const std::string& s )
{
    // s must have been converted to bin
    int len = m_len;
    int s_len = s.length() - 1;
    int min_len = sc_min( len, s_len );
    int i = 0;
    for( ; i < min_len; ++ i ) {
	char c = s[s_len - i - 1];
	if( c != '0' && c != '1' ) {
	    SC_REPORT_ERROR( sc_core::SC_ID_CANNOT_CONVERT_,
	        "string can contain only '0' and '1' characters" );
	}
	set_bit( i, sc_logic_value_t( c - '0' ) );
    }
    // if formatted, fill the rest with sign(s), otherwise fill with zeros
    sc_logic_value_t fill = (s[s_len] == 'F' ? sc_logic_value_t( s[0] - '0' )
		                             : sc_logic_value_t( 0 ));
    for( ; i < len; ++ i ) {
	set_bit( i, fill );
    }
}


// constructors

sc_bv_base::sc_bv_base( const char* a )
    : m_len( 0 ), m_size( 0 ), m_data( 0 )
{
    std::string s = convert_to_bin( a );
    init( s.length() -  1 );
    assign_from_string( s );
}

sc_bv_base::sc_bv_base( const char* a, int length_ )
    : m_len( 0 ), m_size( 0 ), m_data( 0 )
{
    init( length_ );
    assign_from_string( convert_to_bin( a ) );
}

sc_bv_base::sc_bv_base( const sc_bv_base& a )
    : sc_proxy<sc_bv_base>(),
      m_len( a.m_len ),
      m_size( a.m_size ),
      m_data( new sc_digit[m_size] )
{
    // copy the bits
    int sz = m_size;
    for( int i = 0; i < sz; ++ i ) {
	m_data[i] = a.m_data[i];
    }
}


// assignment operators

sc_bv_base&
sc_bv_base::operator = ( const char* a )
{
    assign_from_string( convert_to_bin( a ) );
    return *this;
}


#if 0

// bitwise complement

sc_bv_base&
sc_bv_base::b_not()
{
    int sz = m_size;
    for( int i = 0; i < sz; ++ i ) {
	m_data[i] = ~m_data[i];
    }
    clean_tail();
    return *this;
}


// bitwise left shift

sc_bv_base&
sc_bv_base::operator <<= ( int n )
{
    if( n < 0 ) {
	char msg[BUFSIZ];
	std::sprintf( msg,
		 "left shift operation is only allowed with positive "
		 "shift values, shift value = %d", n );
	SC_REPORT_ERROR( sc_core::SC_ID_OUT_OF_BOUNDS_, msg );
    }
    int sz = m_size;
    if( n >= m_len ) {
	for( int i = 0; i < sz; ++ i ) {
	    m_data[i] = SC_DIGIT_ZERO;
	}
	// clean_tail();
	return *this;
    }
    int wn = n / SC_DIGIT_SIZE;
    int bn = n % SC_DIGIT_SIZE;
    if( wn != 0 ) {
	// shift words
	int i = sz - 1;
	for( ; i >= wn; -- i ) {
	    m_data[i] = m_data[i - wn];
	}
	for( ; i >= 0; -- i ) {
	    m_data[i] = SC_DIGIT_ZERO;
	}
    }
    if( bn != 0 ) {
	// shift bits
	for( int i = sz - 1; i >= 1; -- i ) {
	    m_data[i] <<= bn;
	    m_data[i] |= m_data[i - 1] >> (SC_DIGIT_SIZE - bn);
	}
	m_data[0] <<= bn;
    }
    clean_tail();
    return *this;
}


// bitwise right shift

sc_bv_base&
sc_bv_base::operator >>= ( int n )
{
    if( n < 0 ) {
	char msg[BUFSIZ];
	std::sprintf( msg,
		 "right shift operation is only allowed with positive "
		 "shift values, shift value = %d", n );
	SC_REPORT_ERROR( sc_core::SC_ID_OUT_OF_BOUNDS_, msg );
    }
    int sz = m_size;
    if( n >= m_len ) {
	for( int i = 0; i < sz; ++ i ) {
	    m_data[i] = SC_DIGIT_ZERO;
	}
	// clean_tail();
	return *this;
    }
    int wn = n / SC_DIGIT_SIZE;
    int bn = n % SC_DIGIT_SIZE;
    if( wn != 0 ) {
	// shift words
	int i = 0;
	for( ; i < (sz - wn); ++ i ) {
	    m_data[i] = m_data[i + wn];
	}
	for( ; i < sz; ++ i ) {
	    m_data[i] = SC_DIGIT_ZERO;
	}
    }
    if( bn != 0 ) {
	// shift bits
	for( int i = 0; i < (sz - 1); ++ i ) {
	    m_data[i] >>= bn;
	    m_data[i] |= m_data[i + 1] << (SC_DIGIT_SIZE - bn);
	}
	m_data[sz - 1] >>= bn;
    }
    clean_tail();
    return *this;
}


// bitwise left rotate

sc_bv_base&
sc_bv_base::lrotate( int n )
{
    if( n < 0 ) {
	char msg[BUFSIZ];
	std::sprintf( msg,
		 "left rotate operation is only allowed with positive "
		 "rotate values, rotate value = %d", n );
	SC_REPORT_ERROR( sc_core::SC_ID_OUT_OF_BOUNDS_, msg );
    }
    int len = m_len;
    n %= len;
    *this = (*this << n) | (*this >> (len - n));
    return *this;
}


// bitwise right rotate

sc_bv_base&
sc_bv_base::rrotate( int n )
{
    if( n < 0 ) {
	char msg[BUFSIZ];
	std::sprintf( msg,
		 "right rotate operation is only allowed with positive "
		 "rotate values, rotate value = %d", n );
	SC_REPORT_ERROR( sc_core::SC_ID_OUT_OF_BOUNDS_, msg );
    }
    int len = m_len;
    n %= len;
    *this = (*this >> n) | (*this << (len - n));
    return *this;
}

#endif


// ----------------------------------------------------------------------------

// convert formatted string to binary string

const std::string
convert_to_bin( const char* s )
{
    // Beware: logic character strings cannot start with '0x' or '0X',
    //         because this is seen as a hexadecimal encoding prefix!

    if( s == 0 ) {
	SC_REPORT_ERROR(sc_core::SC_ID_CANNOT_CONVERT_,
	    "character string is zero" );
    }
    if( *s == 0 ) {
	SC_REPORT_ERROR(sc_core::SC_ID_CANNOT_CONVERT_,
	    "character string is empty");
    }

    int n = strlen( s );
    int i = 0;
    if( s[0] == '-' || s[0] == '+' ) {
	++ i;
    }
    if( n > (i + 2) && s[i] == '0' )
    {
        if (s[i+1] == 'b' || s[i+1] == 'B' )
	{
	    if ( s[i+2] == '0' || s[i+2] == '1' )
	    {
		std::string str( &s[2] );
	        str += "F";
	        return str;
	    }
	}
        if ( s[i+1] == 'b' || s[i+1] == 'B' ||
	     s[i+1] == 'c' || s[i+1] == 'C' ||
	     s[i+1] == 'd' || s[i+1] == 'D' ||
	     s[i+1] == 'o' || s[i+1] == 'O' ||
	     s[i+1] == 'x' || s[i+1] == 'X')
        {
	    try {
		// worst case length = n * 4
		sc_fix a( s, n * 4, n * 4, SC_TRN, SC_WRAP, 0, SC_ON );
		std::string str = a.to_bin();
		str += "F"; // mark the string as formatted
		// get rid of prefix (0b) and redundant leading bits
		const char* p = str.c_str() + 2;
		while( p[1] && p[0] == p[1] ) {
		    ++ p;
		}
		return std::string( p );
	    } catch( sc_core::sc_report ) {
		char msg[BUFSIZ];
		std::sprintf( msg, "character string '%s' is not valid", s );
		SC_REPORT_ERROR( sc_core::SC_ID_CANNOT_CONVERT_, msg );
		// never reached
		return std::string();
	    }
	}

    }

    // bin by default

    std::string str( s );
    str += "U"; // mark the string as unformatted
    return str;
}

// convert binary string to formatted string

const std::string
convert_to_fmt( const std::string& s, sc_numrep numrep, bool w_prefix )
{
    int n = s.length();
    std::string str("0bus");
    // str += "0bus";
    str += s;
    sc_ufix a( str.c_str(), n, n, SC_TRN, SC_WRAP, 0, SC_ON );
    return a.to_string( numrep, w_prefix );
}

} // namespace sc_dt