sc_time.cpp

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  set forth in the SystemC Open Source License Version 2.4 (the "License");
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/*****************************************************************************

  sc_time.cpp --

  Original Author: Martin Janssen, Synopsys, Inc., 2001-05-21

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

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

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

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// $Log: sc_time.cpp,v $
// Revision 1.1.1.1  2006/12/15 20:31:37  acg
// SystemC 2.2
//
// Revision 1.6  2006/01/26 21:04:55  acg
//  Andy Goodrich: deprecation message changes and additional messages.
//
// Revision 1.5  2006/01/25 00:31:19  acg
//  Andy Goodrich: Changed over to use a standard message id of
//  SC_ID_IEEE_1666_DEPRECATION for all deprecation messages.
//
// Revision 1.4  2006/01/24 20:49:05  acg
// Andy Goodrich: changes to remove the use of deprecated features within the
// simulator, and to issue warning messages when deprecated features are used.
//
// Revision 1.3  2006/01/13 18:44:30  acg
// Added $Log to record CVS changes into the source.
//

#include <math.h>
#include <stdio.h>

#include "sysc/kernel/sc_kernel_ids.h"
#include "sysc/kernel/sc_simcontext.h"
#include "sysc/kernel/sc_time.h"
#include "sysc/utils/sc_utils_ids.h"

namespace sc_core {

static
double time_values[] = {
    1,       // fs
    1e3,     // ps
    1e6,     // ns
    1e9,     // us
    1e12,    // ms
    1e15     // s
};

static
const char* time_units[] = {
    "fs",
    "ps",
    "ns",
    "us",
    "ms",
    "s"
};


// ----------------------------------------------------------------------------
//  CLASS : sc_time
//
//  The time class.
// ----------------------------------------------------------------------------

// constructors

sc_time::sc_time( double v, sc_time_unit tu )
: m_value( 0 )
{
    if( v != 0 ) {
    sc_time_params* time_params = sc_get_curr_simcontext()->m_time_params;
    double scale_fac = time_values[tu] / time_params->time_resolution;
    // linux bug workaround; don't change next two lines
    volatile double tmp = v * scale_fac + 0.5;
    m_value = SCAST<sc_dt::int64>( tmp );
    time_params->time_resolution_fixed = true;
    }
}

sc_time::sc_time( double v, sc_time_unit tu, sc_simcontext* simc )
: m_value( 0 )
{
    if( v != 0 ) {
    sc_time_params* time_params = simc->m_time_params;
    double scale_fac = time_values[tu] / time_params->time_resolution;
    // linux bug workaround; don't change next two lines
    volatile double tmp = v * scale_fac + 0.5;
    m_value = SCAST<sc_dt::int64>( tmp );
    time_params->time_resolution_fixed = true;
    }
}

sc_time::sc_time( double v, bool scale )
: m_value( 0 )
{
    if( v != 0 ) {
    sc_time_params* time_params = sc_get_curr_simcontext()->m_time_params;
    if( scale ) {
        double scale_fac = sc_dt::uint64_to_double(
        time_params->default_time_unit );
        // linux bug workaround; don't change next two lines
        volatile double tmp = v * scale_fac + 0.5;
        m_value = SCAST<sc_dt::int64>( tmp );
    } else {
        // linux bug workaround; don't change next two lines
        volatile double tmp = v + 0.5;
        m_value = SCAST<sc_dt::int64>( tmp );
    }
    time_params->time_resolution_fixed = true;
    }
}

sc_time::sc_time( sc_dt::uint64 v, bool scale )
: m_value( 0 )
{
    if( v != 0 ) {
    sc_time_params* time_params = sc_get_curr_simcontext()->m_time_params;
    if( scale ) {
        double scale_fac = sc_dt::uint64_to_double(
        time_params->default_time_unit );
        // linux bug workaround; don't change next two lines
        volatile double tmp = sc_dt::uint64_to_double( v ) *
                          scale_fac + 0.5;
        m_value = SCAST<sc_dt::int64>( tmp );
    } else {
        m_value = v;
    }
    time_params->time_resolution_fixed = true;
    }
}


// conversion functions

double
sc_time::to_default_time_units() const
{
    sc_time_params* time_params = sc_get_curr_simcontext()->m_time_params;
    return ( sc_dt::uint64_to_double( m_value ) /
         sc_dt::uint64_to_double( time_params->default_time_unit ) );
}

double
sc_time::to_seconds() const
{
    sc_time_params* time_params = sc_get_curr_simcontext()->m_time_params;
    return ( sc_dt::uint64_to_double( m_value ) *
         time_params->time_resolution * 1e-15 );
}

const std::string
sc_time::to_string() const
{
    sc_dt::uint64 val = m_value;
    if( val == 0 ) {
    return std::string( "0 s" );
    }
    sc_time_params* time_params = sc_get_curr_simcontext()->m_time_params;
    sc_dt::uint64 tr = SCAST<sc_dt::int64>( time_params->time_resolution );
    int n = 0;
    while( ( tr % 10 ) == 0 ) {
    tr /= 10;
    n ++;
    }
    assert( tr == 1 );
    while( ( val % 10 ) == 0 ) {
    val /= 10;
    n ++;
    }
    char buf[BUFSIZ];
#if !defined( _MSC_VER )
    std::sprintf( buf, "%llu", val );
#else
    std::sprintf( buf, "%I64u", val );
#endif
    std::string result( buf );
    if( n >= 15 ) {
    for( int i = n - 15; i > 0; -- i ) {
        result += "0";
    }
    result += " s";
    } else {
    for( int i = n % 3; i > 0; -- i ) {
        result += "0";
    }
    result += " ";
    result += time_units[n / 3];
    }
    return result;
}


// print function

void
sc_time::print( ::std::ostream& os ) const
{
    os << to_string();
}


// ----------------------------------------------------------------------------
//  STRUCT : sc_time_params
//
//  Struct that holds the time resolution and default time unit.
// ----------------------------------------------------------------------------

sc_time_params::sc_time_params()
: time_resolution( 1000 ),      // default 1 ps
  time_resolution_specified( false ),
  time_resolution_fixed( false ),
  default_time_unit( 1000 ),        // default 1 ns
  default_time_unit_specified( false )
{}

sc_time_params::~sc_time_params()
{}


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

// functions for accessing the time resolution and default time unit

void
sc_set_time_resolution( double v, sc_time_unit tu )
{
    // first perform the necessary checks

    // must be positive
    if( v < 0.0 ) {
    SC_REPORT_ERROR( SC_ID_SET_TIME_RESOLUTION_, "value not positive" );
    }

    // must be a power of ten
    double dummy;
#if defined( __HP_aCC ) || defined(__ppc__)
    // aCC seems to have a bug in modf()
    if( modf( log10( v < 1.0 ? 1.0/v : v ), &dummy ) != 0.0 ) {
#else
    if( modf( log10( v ), &dummy ) != 0.0 ) {
#endif
    SC_REPORT_ERROR( SC_ID_SET_TIME_RESOLUTION_,
             "value not a power of ten" );
    }

    sc_simcontext* simc = sc_get_curr_simcontext();

    // can only be specified during elaboration
    if( sc_is_running() ) {
    SC_REPORT_ERROR( SC_ID_SET_TIME_RESOLUTION_, "simulation running" );
    }

    sc_time_params* time_params = simc->m_time_params;

    // can be specified only once
    if( time_params->time_resolution_specified ) {
    SC_REPORT_ERROR( SC_ID_SET_TIME_RESOLUTION_, "already specified" );
    }

    // can only be specified before any sc_time is constructed
    if( time_params->time_resolution_fixed ) {
    SC_REPORT_ERROR( SC_ID_SET_TIME_RESOLUTION_,
             "sc_time object(s) constructed" );
    }

    // must be larger than or equal to 1 fs
    volatile double resolution = v * time_values[tu];
    if( resolution < 1.0 ) {
    SC_REPORT_ERROR( SC_ID_SET_TIME_RESOLUTION_,
             "value smaller than 1 fs" );
    }

    // recalculate the default time unit
    volatile double time_unit = sc_dt::uint64_to_double(
    time_params->default_time_unit ) *
    ( time_params->time_resolution / resolution );
    if( time_unit < 1.0 ) {
    SC_REPORT_WARNING( SC_ID_DEFAULT_TIME_UNIT_CHANGED_, 0 );
    time_params->default_time_unit = 1;
    } else {
    time_params->default_time_unit = SCAST<sc_dt::int64>( time_unit );
    }

    time_params->time_resolution = resolution;
    time_params->time_resolution_specified = true;
}

sc_time 
sc_get_time_resolution()
{
    return sc_time( sc_dt::UINT64_ONE, false );
}


void
sc_set_default_time_unit( double v, sc_time_unit tu )
{
    static bool warn_default_time_unit=true;
    if ( warn_default_time_unit )
    {
        warn_default_time_unit=false;
        SC_REPORT_INFO(SC_ID_IEEE_1666_DEPRECATION_,
        "deprecated function: sc_set_default_time_unit");
    }
    
    // first perform the necessary checks

    // must be positive
    if( v < 0.0 ) {
    SC_REPORT_ERROR( SC_ID_SET_DEFAULT_TIME_UNIT_, "value not positive" );
    }

    // must be a power of ten
    double dummy;
    if( modf( log10( v ), &dummy ) != 0.0 ) {
    SC_REPORT_ERROR( SC_ID_SET_DEFAULT_TIME_UNIT_,
             "value not a power of ten" );
    }

    sc_simcontext* simc = sc_get_curr_simcontext();

    // can only be specified during elaboration
    if( sc_is_running() ) {
    SC_REPORT_ERROR( SC_ID_SET_DEFAULT_TIME_UNIT_, "simulation running" );
    }

    sc_time_params* time_params = simc->m_time_params;

    // can only be specified before any sc_time is constructed
    if( time_params->time_resolution_fixed ) {
        SC_REPORT_ERROR( SC_ID_SET_DEFAULT_TIME_UNIT_,
                         "sc_time object(s) constructed" );
    }

    // can be specified only once
    if( time_params->default_time_unit_specified ) {
    SC_REPORT_ERROR( SC_ID_SET_DEFAULT_TIME_UNIT_, "already specified" );
    }

    // must be larger than or equal to the time resolution
    volatile double time_unit = ( v * time_values[tu] ) /
                            time_params->time_resolution;
    if( time_unit < 1.0 ) {
    SC_REPORT_ERROR( SC_ID_SET_DEFAULT_TIME_UNIT_,
             "value smaller than time resolution" );
    }

    time_params->default_time_unit = SCAST<sc_dt::int64>( time_unit );
    time_params->default_time_unit_specified = true;
}

sc_time
sc_get_default_time_unit()
{
    bool warn_get_default_time_unit = true;
    if ( warn_get_default_time_unit )
    {
        warn_get_default_time_unit=false;
        SC_REPORT_INFO(SC_ID_IEEE_1666_DEPRECATION_,
            "deprecated function: sc_get_default_time_unit");
    }
    return sc_time( sc_get_curr_simcontext()->m_time_params->default_time_unit,
            false );
}


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

const sc_time SC_ZERO_TIME;


} // namespace sc_core
// Taf!

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