src/systemc/ext/dt/bit/sc_logic.hh

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  Licensed to Accellera Systems Initiative Inc. (Accellera) under one or
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  with this work for additional information regarding copyright ownership.
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  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
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/*****************************************************************************

  sc_logic.h -- C++ implementation of logic type. Behaves
                pretty much the same way as HDLs except with 4 values.

  Original Author: Stan Y. Liao, Synopsys, Inc.

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

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

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

      Name, Affiliation, Date:
  Description of Modification:

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

// $Log: sc_logic.h,v $
// Revision 1.3  2011/08/07 18:54:19  acg
//  Philipp A. Hartmann: remove friend function declarations that implement
//  code, and clean up how bit and logic operators are defined in general.
//
// Revision 1.2  2011/01/25 20:50:37  acg
//  Andy Goodrich: changes for IEEE 1666 2011.
//
// Revision 1.1.1.1  2006/12/15 20:20:04  acg
// SystemC 2.3
//
// Revision 1.5  2006/12/02 21:00:57  acg
//  Andy Goodrich: fixes for concatenation support.
//
// Revision 1.4  2006/05/08 17:49:59  acg
//   Andy Goodrich: Added David Long's declarations for friend operators,
//   functions, and methods, to keep the Microsoft compiler happy.
//
// Revision 1.3  2006/01/13 18:53:53  acg
// Andy Goodrich: added $Log command so that CVS comments are reproduced in
// the source.
//

#ifndef __SYSTEMC_EXT_DT_BIT_SC_LOGIC_HH__
#define __SYSTEMC_EXT_DT_BIT_SC_LOGIC_HH__

#include <cstdio>
#include <iostream>

#include "../sc_mempool.hh"
#include "sc_bit.hh"

namespace sc_dt
{

// classes defined in this module
class sc_logic;


// ----------------------------------------------------------------------------
//  ENUM : sc_logic_value_t
//
//  Enumeration of values for sc_logic.
// ----------------------------------------------------------------------------

enum sc_logic_value_t
{
    Log_0 = 0,
    Log_1,
    Log_Z,
    Log_X
};

// ----------------------------------------------------------------------------
//  CLASS : sc_logic
//
//  Four-valued logic type.
// ----------------------------------------------------------------------------

class sc_logic
{
  private:
    // support methods
    static void invalid_value(sc_logic_value_t);
    static void invalid_value(char);
    static void invalid_value(int);

    static sc_logic_value_t
    to_value(sc_logic_value_t v)
    {
        if (v < Log_0 || v > Log_X) {
            invalid_value(v);
            // may continue, if suppressed
            v = Log_X;
        }
        return v;
    }

    static sc_logic_value_t to_value(bool b) { return (b ? Log_1 : Log_0); }

    static sc_logic_value_t
    to_value(char c)
    {
        unsigned int index = (int)c;
        if (index > 127) {
            invalid_value(c);
            // may continue, if suppressed
            index = 127; // aka Log_X
        }
        return char_to_logic[index];
    }

    static sc_logic_value_t
    to_value(int i)
    {
        if (i < Log_0 || i > Log_X) {
            invalid_value(i);
            // may continue, if suppressed
            i = Log_X;
        }
        return sc_logic_value_t(i);
    }

    void invalid_01() const;

  public:
    // conversion tables
    static const sc_logic_value_t char_to_logic[128];
    static const char logic_to_char[4];
    static const sc_logic_value_t and_table[4][4];
    static const sc_logic_value_t or_table[4][4];
    static const sc_logic_value_t xor_table[4][4];
    static const sc_logic_value_t not_table[4];

    // constructors
    sc_logic() : m_val(Log_X) {}
    sc_logic(const sc_logic &a) : m_val(a.m_val) {}
    sc_logic(sc_logic_value_t v) : m_val(to_value(v)) {}
    explicit sc_logic(bool a) : m_val(to_value(a)) {}
    explicit sc_logic(char a) : m_val(to_value(a)) {}
    explicit sc_logic(int a) : m_val(to_value(a)) {}
    explicit sc_logic(const sc_bit &a) : m_val(to_value(a.to_bool())) {}

    // destructor
    ~sc_logic() {}

    // (bitwise) assignment operators
#define DEFN_ASN_OP_T(op,tp) \
    sc_logic & \
    operator op (tp v) \
    { \
        *this op sc_logic(v); \
        return *this; \
    }

#define DEFN_ASN_OP(op) \
    DEFN_ASN_OP_T(op, sc_logic_value_t) \
    DEFN_ASN_OP_T(op, bool) \
    DEFN_ASN_OP_T(op, char) \
    DEFN_ASN_OP_T(op, int) \
    DEFN_ASN_OP_T(op, const sc_bit &)

    sc_logic &
    operator = (const sc_logic &a)
    {
        m_val = a.m_val;
        return *this;
    }

    sc_logic &
    operator &= (const sc_logic &b)
    {
        m_val = and_table[m_val][b.m_val];
        return *this;
    }

    sc_logic &
    operator |= (const sc_logic &b)
    {
        m_val = or_table[m_val][b.m_val];
        return *this;
    }

    sc_logic &
    operator ^= (const sc_logic &b)
    {
        m_val = xor_table[m_val][b.m_val];
        return *this;
    }

    DEFN_ASN_OP(=)
    DEFN_ASN_OP(&=)
    DEFN_ASN_OP(|=)
    DEFN_ASN_OP(^=)

#undef DEFN_ASN_OP_T
#undef DEFN_ASN_OP

    // bitwise operators and functions
    friend const sc_logic operator & (const sc_logic &, const sc_logic &);
    friend const sc_logic operator | (const sc_logic &, const sc_logic &);
    friend const sc_logic operator ^ (const sc_logic &, const sc_logic &);

    // relational operators
    friend bool operator == (const sc_logic &, const sc_logic &);
    friend bool operator != (const sc_logic &, const sc_logic &);

    // bitwise complement
    const sc_logic operator ~ () const { return sc_logic(not_table[m_val]); }
    sc_logic &
    b_not()
    {
        m_val = not_table[m_val];
        return *this;
    }

    // explicit conversions
    sc_logic_value_t value() const { return m_val; }

    bool is_01() const { return ((int)m_val == Log_0 || (int)m_val == Log_1); }
    bool
    to_bool() const
    {
        if (!is_01()) {
            invalid_01();
        }
        return ((int)m_val != Log_0);
    }

    char to_char() const { return logic_to_char[m_val]; }

    // other methods
    void print(::std::ostream &os=::std::cout) const { os << to_char(); }
    void scan(::std::istream &is=::std::cin);

    // memory (de)allocation
    // placement new
    static void *operator new (std::size_t, void *p) { return p; }
    static void *
    operator new (std::size_t sz)
    {
        return sc_core::sc_mempool::allocate(sz);
    }
    static void
    operator delete (void *p, std::size_t sz)
    {
        sc_core::sc_mempool::release(p, sz);
    }
    static void *
    operator new [] (std::size_t sz)
    {
        return sc_core::sc_mempool::allocate(sz);
    }
    static void
    operator delete [] (void *p, std::size_t sz)
    {
        sc_core::sc_mempool::release(p, sz);
    }

  private:
    sc_logic_value_t m_val;

  private:
    // Disabled
    explicit sc_logic(const char *);
    sc_logic &operator = (const char *);
};

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

// bitwise operators
inline const sc_logic
operator & (const sc_logic &a, const sc_logic &b)
{
    return sc_logic(sc_logic::and_table[a.m_val][b.m_val]);
}

inline const sc_logic
operator | (const sc_logic &a, const sc_logic &b)
{
    return sc_logic(sc_logic::or_table[a.m_val][b.m_val]);
}

inline const sc_logic
operator ^ (const sc_logic &a, const sc_logic &b)
{
    return sc_logic(sc_logic::xor_table[a.m_val][b.m_val]);
}

#define DEFN_BIN_OP_T(ret,op,tp) \
    inline ret \
    operator op (const sc_logic &a, tp b) \
    { \
        return (a op sc_logic(b)); \
    } \
    inline ret \
    operator op (tp a, const sc_logic &b) \
    { \
        return (sc_logic(a) op b); \
    }

#define DEFN_BIN_OP(ret, op) \
    DEFN_BIN_OP_T(ret, op, sc_logic_value_t) \
    DEFN_BIN_OP_T(ret, op, bool) \
    DEFN_BIN_OP_T(ret, op, char) \
    DEFN_BIN_OP_T(ret, op, int)

DEFN_BIN_OP(const sc_logic, &)
DEFN_BIN_OP(const sc_logic, |)
DEFN_BIN_OP(const sc_logic, ^)

// relational operators and functions

inline bool
operator == (const sc_logic &a, const sc_logic &b)
{
    return ((int)a.m_val == b.m_val);
}

inline bool
operator != (const sc_logic &a, const sc_logic &b)
{
    return ((int)a.m_val != b.m_val);
}

DEFN_BIN_OP(bool, ==)
DEFN_BIN_OP(bool, !=)

#undef DEFN_BIN_OP_T
#undef DEFN_BIN_OP

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

inline ::std::ostream &
operator << (::std::ostream &os, const sc_logic &a)
{
    a.print(os);
    return os;
}

inline ::std::istream &
operator >> (::std::istream &is, sc_logic &a)
{
    a.scan(is);
    return is;
}


extern const sc_logic SC_LOGIC_0;
extern const sc_logic SC_LOGIC_1;
extern const sc_logic SC_LOGIC_Z;
extern const sc_logic SC_LOGIC_X;

// #ifdef SC_DT_DEPRECATED
extern const sc_logic sc_logic_0;
extern const sc_logic sc_logic_1;
extern const sc_logic sc_logic_Z;
extern const sc_logic sc_logic_X;
// #endif

} // namespace sc_dt

#endif // __SYSTEMC_EXT_DT_BIT_SC_LOGIC_HH__