scfx_utils.h

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  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_utils.h - 

  Original Author: Martin Janssen, Synopsys, Inc.

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

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

  MODIFICATION LOG - modifiers, enter your name, affiliation, date and
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// $Log: scfx_utils.h,v $
// Revision 1.2  2009/02/28 00:26:20  acg
//  Andy Goodrich: bug fixes.
//
// Revision 1.1.1.1  2006/12/15 20:31:36  acg
// SystemC 2.2
//
// 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_UTILS_H
#define SCFX_UTILS_H


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


namespace sc_dt
{

// ----------------------------------------------------------------------------
//  Find the most and least significant non-zero bits in a unsigned long
// ----------------------------------------------------------------------------

#define MSB_STATEMENT(n) if( x >> n ) { x >>= n; i += n; }

inline
int
scfx_find_msb( unsigned long x )
{
    int i = 0;
#   if defined(SC_LONG_64)
        MSB_STATEMENT( 32 );
#   endif // defined(SC_LONG_64)
    MSB_STATEMENT( 16 );
    MSB_STATEMENT( 8 );
    MSB_STATEMENT( 4 );
    MSB_STATEMENT( 2 );
    MSB_STATEMENT( 1 );
    return i;
}

#undef MSB_STATEMENT

#define LSB_STATEMENT(n) if( x << n ) { x <<= n; i -= n; }

inline
int
scfx_find_lsb( unsigned long x )
{
    int i;
#   if defined(SC_LONG_64)
        i = 63;
        LSB_STATEMENT( 32 );
#   else
        i = 31;
#   endif // defined(SC_LONG_64)
    LSB_STATEMENT( 16 );
    LSB_STATEMENT( 8 );
    LSB_STATEMENT( 4 );
    LSB_STATEMENT( 2 );
    LSB_STATEMENT( 1 );
    return i;
}

#undef LSB_STATEMENT


// ----------------------------------------------------------------------------
//  Utilities for parsing a character string number
// ----------------------------------------------------------------------------

inline
int
scfx_parse_sign( const char*& s, bool& sign_char )
{
    int sign = 1;

    if( *s == '+' )
    {
        ++ s;
        sign_char = true;
    }
    else if( *s == '-' )
    {
        sign = -1;
        ++ s;
        sign_char = true;
    }
    else
        sign_char = false;

    return sign;
}

inline
sc_numrep
scfx_parse_prefix( const char*& s )
{
    if( s[0] == '0' ) {
        switch( s[1] )
        {
            case 'b':
            case 'B':
            {
                if( (s[2] == 'u' || s[2] == 'U') && (s[3] == 's' || s[3] == 'S') ) {
                    s += 4;
                    return SC_BIN_US;
                }
                if( (s[2] == 's' || s[2] == 'S') && (s[3] == 'm' || s[3] == 'M') ) {
                    s += 4;
                    return SC_BIN_SM;
                }
                s += 2;
                return SC_BIN;
            }
            case 'o':
            case 'O':
            {
                if( (s[2] == 'u' || s[2] == 'U') && (s[3] == 's' || s[3] == 'S') ) {
                    s += 4;
                    return SC_OCT_US;
                }
                if( (s[2] == 's' || s[2] == 'S') && (s[3] == 'm' || s[3] == 'M') ) {
                    s += 4;
                    return SC_OCT_SM;
                }
                s += 2;
                return SC_OCT;
            }
            case 'x':
            case 'X':
            {
                if( (s[2] == 'u' || s[2] == 'U') && (s[3] == 's' || s[3] == 'S') ) {
                    s += 4;
                    return SC_HEX_US;
                }
                if( (s[2] == 's' || s[2] == 'S') && (s[3] == 'm' || s[3] == 'M') ) {
                    s += 4;
                    return SC_HEX_SM;
                }
                s += 2;
                return SC_HEX;
            }
            case 'd':
            case 'D':
            {
                s += 2;
                return SC_DEC;
            }
            case 'c':
            case 'C':
            {
                if( (s[2] == 's' || s[2] == 'S') && (s[3] == 'd' || s[3] == 'D') ) {
                    s += 4;
                    return SC_CSD;
                }
                break;
            }
            default:
                break;
        }
    }

    return SC_DEC;
}


inline
int
scfx_parse_base( const char*& s )
{
    const char* s1 = s + 1;

    int base = 10;

    if( *s == '0' )
    {
        switch( *s1 )
        {
            case 'b':
            case 'B': base =  2; s += 2; break;
            case 'o':
            case 'O': base =  8; s += 2; break;
            case 'd':
            case 'D': base = 10; s += 2; break;
            case 'x':
            case 'X': base = 16; s += 2; break;
        }
    }

    return base;
}

inline
bool
scfx_is_equal( const char* a, const char* b )
{
    while( *a != 0 && *b != 0 && *a == *b )
    {
        ++ a;
        ++ b;
    }
    return ( *a == 0 && *b == 0 );
}

inline
bool
scfx_is_nan( const char* s )
{
    return scfx_is_equal( s, "NaN" );
}

inline
bool
scfx_is_inf( const char* s )
{
    return ( scfx_is_equal( s, "Inf" ) || scfx_is_equal( s, "Infinity" ) );
}

inline
bool
scfx_exp_start( const char* s )
{
    if( *s == 'e' || *s == 'E' )
    {
        ++ s;
        if( *s == '+' || *s == '-' )
            return true;
    }
    return false;
}

inline
bool
scfx_is_digit( char c, sc_numrep numrep )
{
    bool is_digit;

    switch( numrep )
    {
        case SC_DEC:
        {
            switch( c )
            {
                case '0': case '1': case '2': case '3': case '4':
                case '5': case '6': case '7': case '8': case '9':
                {
                    is_digit = true;
                    break;
                }
                default:
                    is_digit = false;
            }
            break;
        }
        case SC_BIN:
        case SC_BIN_US:
        case SC_BIN_SM:
        {
            switch( c )
            {
                case '0': case '1':
                {
                    is_digit = true;
                    break;
                }
                default:
                    is_digit = false;
            }
            break;
        }
        case SC_OCT:
        case SC_OCT_US:
        case SC_OCT_SM:
        {
            switch( c )
            {
                case '0': case '1': case '2': case '3':
                case '4': case '5': case '6': case '7':
                {
                    is_digit = true;
                    break;
                }
                default:
                    is_digit = false;
            }
            break;
        }
        case SC_HEX:
        case SC_HEX_US:
        case SC_HEX_SM:
        {
            switch( c )
            {
                case '0': case '1': case '2': case '3': case '4':
                case '5': case '6': case '7': case '8': case '9':
                case 'a': case 'b': case 'c': case 'd': case 'e': case 'f':
                case 'A': case 'B': case 'C': case 'D': case 'E': case 'F':
                {
                    is_digit = true;
                    break;
                }
                default:
                    is_digit = false;
            }
            break;
        }
        case SC_CSD:
        {
            switch( c )
            {
                case '0': case '1': case '-':
                {
                    is_digit = true;
                    break;
                }
                default:
                    is_digit = false;
            }
            break;
        }
        default:
            is_digit = false;
    }

    return is_digit;
}

inline
int
scfx_to_digit( char c, sc_numrep numrep )
{
    int to_digit;
    
    switch( numrep )
    {
        case SC_DEC:
        case SC_BIN:
        case SC_BIN_US:
        case SC_BIN_SM:
        case SC_OCT:
        case SC_OCT_US:
        case SC_OCT_SM:
        {
            to_digit = c - '0';
            break;
        }
        case SC_HEX:
        case SC_HEX_US:
        case SC_HEX_SM:
        {
            switch( c )
            {
                case '0': case '1': case '2': case '3': case '4':
                case '5': case '6': case '7': case '8': case '9':
                    to_digit = c - '0';
                    break;
                case 'a': case 'b': case 'c': case 'd': case 'e': case 'f':
                    to_digit = c - 'a' + 10;
                    break;
                case 'A': case 'B': case 'C': case 'D': case 'E': case 'F':
                    to_digit = c - 'A' + 10;
                    break;
                default:
                    to_digit = -2;
            }
            break;
        }
        case SC_CSD:
        {
            if( c == '-' )
                to_digit = -1;
            else
                to_digit = c - '0';
            break;
        }
        default:
            to_digit = -2;
    }

    return to_digit;
}


// ----------------------------------------------------------------------------
//  Utilities for printing a character string number
// ----------------------------------------------------------------------------

inline
void
scfx_print_nan( scfx_string& s )
{
    s += "NaN";
}

inline
void
scfx_print_inf( scfx_string& s, bool negative )
{
    if( negative )
        s += "-Inf";
    else
        s += "Inf";
}

inline
void
scfx_print_prefix( scfx_string& s, sc_numrep numrep )
{
    switch( numrep )
    {
        case SC_DEC:
            s += "0d";
            break;
        case SC_BIN:
            s += "0b";
            break;
        case SC_BIN_US:
            s += "0bus";
            break;
        case SC_BIN_SM:
            s += "0bsm";
            break;
        case SC_OCT:
            s += "0o";
            break;
        case SC_OCT_US:
            s += "0ous";
            break;
        case SC_OCT_SM:
            s += "0osm";
            break;
        case SC_HEX:
            s += "0x";
            break;
        case SC_HEX_US:
            s += "0xus";
            break;
        case SC_HEX_SM:
            s += "0xsm";
            break;
        case SC_CSD:
            s += "0csd";
            break;
        default:
            s += "unknown";
    }
}

inline
void
scfx_print_exp( scfx_string& s, int exp )
{
    if( exp != 0 )
    {
        s += 'e';
                
        if( exp < 0 )
        {
            exp = - exp;
            s += '-';
        }
        else
            s += '+';

        bool first = true;
        int scale = 1000000000;
        do
        {
            int digit = exp / scale;
            exp = exp % scale;
            if( digit != 0 || ! first )
            {
                s += static_cast<char>( digit + '0' );
                first = false;
            }
            scale /= 10;
        }
        while( scale > 0 );
    }
}


void scfx_tc2csd( scfx_string&, int );
void scfx_csd2tc( scfx_string& );

} // namespace sc_dt


#endif

// Taf!