src/systemc/dt/bit/sc_bv_base.cc

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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 <cstring>
#include <sstream>

#include "systemc/ext/dt/bit/sc_bv_base.hh"
#include "systemc/ext/dt/fx/sc_fix.hh"
#include "systemc/ext/dt/fx/sc_ufix.hh"
#include "systemc/ext/utils/sc_report.hh"

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("zero length", 0);
        sc_core::sc_abort(); // can't recover from here
    }
    // 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("cannot perform conversion",
                "string can contain only '0' and '1' characters");
            // may continue, if suppressed
            c = '0';
        }
        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;
}


// ----------------------------------------------------------------------------
// 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("cannot perform conversion",
            "character string is zero");
        return std::string();
    }
    if (*s == 0) {
        SC_REPORT_ERROR("cannot perform conversion",
            "character string is empty");
        return std::string();
    }

    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 (const sc_core::sc_report &) {
                std::stringstream msg;
                msg << "character string '" << s << "' is not valid";
                SC_REPORT_ERROR("cannot perform conversion",
                        msg.str().c_str());
                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