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

  The following code is derived, directly or indirectly, from the SystemC
  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
  ANY KIND, either express or implied. See the License for the specific
  language governing rights and limitations under the License.

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

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

  sc_time.cpp --

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

  CHANGE LOG AT THE END OF THE FILE
 *****************************************************************************/


#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"

#if !defined(PRIu64)
#   if defined(_MSC_VER) || defined(__MINGW32__)
#       define PRIu64 "I64u"
#   else
#       define PRIu64 "llu"
#   endif
#endif // PRIu64

#ifdef SC_ENABLE_EARLY_MAXTIME_CREATION
#  define SC_MAXTIME_ALLOWED_ 1
#else
#  define SC_MAXTIME_ALLOWED_ 0
#endif

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 )
{
    static bool warn_constructor=true;
    if ( warn_constructor ) {
        warn_constructor=false;
        SC_REPORT_INFO(SC_ID_IEEE_1666_DEPRECATION_,
            "deprecated constructor: sc_time(double,bool)");
    }

    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( value_type v, bool scale )
: m_value( 0 )
{
    static bool warn_constructor=true;
    if ( warn_constructor ) {
        warn_constructor=false;
        SC_REPORT_INFO(SC_ID_IEEE_1666_DEPRECATION_,
            "deprecated constructor: sc_time(uint64,bool)");
    }

    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;
    }
}

sc_time
sc_time::from_value( value_type v )
{
    sc_time t;
    if( v != 0 && !(SC_MAXTIME_ALLOWED_ && v == ~sc_dt::UINT64_ZERO) ) {
        sc_time_params* time_params = sc_get_curr_simcontext()->m_time_params;
        time_params->time_resolution_fixed = true;
    }
    t.m_value = v;
    return t;
}


// conversion functions

double
sc_time::to_default_time_units() const
{
    sc_time_params* time_params = sc_get_curr_simcontext()->m_time_params;
#   if SC_MAXTIME_ALLOWED_
        if( m_value == 0 )
            return 0.0;
        time_params->time_resolution_fixed = true;
#   endif // SC_MAXTIME_ALLOWED_
    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;
#   if SC_MAXTIME_ALLOWED_
        if( m_value == 0 )
            return 0.0;
        time_params->time_resolution_fixed = true;
#   endif // SC_MAXTIME_ALLOWED_
    return ( sc_dt::uint64_to_double( m_value ) *
	     time_params->time_resolution * 1e-15 );
}

const std::string
sc_time::to_string() const
{
    value_type val = m_value;
    if( val == 0 ) {
	return std::string( "0 s" );
    }
    sc_time_params* time_params = sc_get_curr_simcontext()->m_time_params;
#   if SC_MAXTIME_ALLOWED_
        time_params->time_resolution_fixed = true;
#   endif // SC_MAXTIME_ALLOWED_
    value_type 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];
    std::sprintf( buf, "%" PRIu64, val );
    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::from_value( sc_dt::UINT64_ONE );
}


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()
{
    static 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::from_value(
              sc_get_curr_simcontext()->m_time_params->default_time_unit
           );
}


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

const sc_time SC_ZERO_TIME;

#undef SC_MAXTIME_ALLOWED_

} // namespace sc_core

// $Log: sc_time.cpp,v $
// Revision 1.7  2011/08/26 20:46:11  acg
//  Andy Goodrich: moved the modification log to the end of the file to
//  eliminate source line number skew when check-ins are done.
//
// Revision 1.6  2011/07/24 16:08:36  acg
//  Philipp A. Hartmann: fix C99 format specifiers for Solaris.
//
// Revision 1.5  2011/02/18 20:27:14  acg
//  Andy Goodrich: Updated Copyrights.
//
// Revision 1.4  2011/02/13 21:47:38  acg
//  Andy Goodrich: update copyright notice.
//
// Revision 1.3  2011/01/19 23:21:50  acg
//  Andy Goodrich: changes for IEEE 1666 2011
//
// Revision 1.2  2008/05/22 17:06:27  acg
//  Andy Goodrich: updated copyright notice to include 2008.
//
// Revision 1.1.1.1  2006/12/15 20:20:05  acg
// SystemC 2.3
//
// 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.
//

// Taf!
