/**CFile****************************************************************

  FileName    [abcXsim.c]

  SystemName  [ABC: Logic synthesis and verification system.]

  PackageName [Network and node package.]

  Synopsis    [Using X-valued simulation.]

  Author      [Alan Mishchenko]
  
  Affiliation [UC Berkeley]

  Date        [Ver. 1.0. Started - June 20, 2005.]

  Revision    [$Id: abcXsim.c,v 1.00 2005/06/20 00:00:00 alanmi Exp $]

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

#include "abc.h"

////////////////////////////////////////////////////////////////////////
///                        DECLARATIONS                              ///
////////////////////////////////////////////////////////////////////////

#define XVS0   ABC_INIT_ZERO
#define XVS1   ABC_INIT_ONE
#define XVSX   ABC_INIT_DC

static inline void Abc_ObjSetXsim( Abc_Obj_t * pObj, int Value )  { pObj->pCopy = (void *)Value;  }
static inline int  Abc_ObjGetXsim( Abc_Obj_t * pObj )             { return (int)pObj->pCopy;      }
static inline int  Abc_XsimInv( int Value )   
{ 
    if ( Value == XVS0 )
        return XVS1;
    if ( Value == XVS1 )
        return XVS0;
    assert( Value == XVSX );       
    return XVSX;
}
static inline int  Abc_XsimAnd( int Value0, int Value1 )   
{ 
    if ( Value0 == XVS0 || Value1 == XVS0 )
        return XVS0;
    if ( Value0 == XVSX || Value1 == XVSX )
        return XVSX;
    assert( Value0 == XVS1 && Value1 == XVS1 );
    return XVS1;
}
static inline int  Abc_XsimRand2()   
{
    return (rand() & 1) ? XVS1 : XVS0;
}
static inline int  Abc_XsimRand3()   
{
    int RetValue;
    do { 
        RetValue = rand() & 3; 
    } while ( RetValue == 0 );
    return RetValue;
}
static inline int  Abc_ObjGetXsimFanin0( Abc_Obj_t * pObj )       
{ 
    int RetValue;
    RetValue = Abc_ObjGetXsim(Abc_ObjFanin0(pObj));
    return Abc_ObjFaninC0(pObj)? Abc_XsimInv(RetValue) : RetValue;
}
static inline int  Abc_ObjGetXsimFanin1( Abc_Obj_t * pObj )       
{ 
    int RetValue;
    RetValue = Abc_ObjGetXsim(Abc_ObjFanin1(pObj));
    return Abc_ObjFaninC1(pObj)? Abc_XsimInv(RetValue) : RetValue;
}
static inline void Abc_XsimPrint( FILE * pFile, int Value )   
{ 
    if ( Value == XVS0 )
    {
        fprintf( pFile, "0" );
        return;
    }
    if ( Value == XVS1 )
    {
        fprintf( pFile, "1" );
        return;
    }
    assert( Value == XVSX );       
    fprintf( pFile, "x" );
}

////////////////////////////////////////////////////////////////////////
///                     FUNCTION DEFINITIONS                         ///
////////////////////////////////////////////////////////////////////////

/**Function*************************************************************

  Synopsis    [Performs X-valued simulation of the sequential network.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void Abc_NtkXValueSimulate( Abc_Ntk_t * pNtk, int nFrames, int fInputs, int fVerbose )
{
    Abc_Obj_t * pObj;
    int i, f;
    assert( Abc_NtkIsStrash(pNtk) );
    srand( 0x12341234 );
    // start simulation
    Abc_ObjSetXsim( Abc_AigConst1(pNtk), XVS1 );
    if ( fInputs )
    {
        Abc_NtkForEachPi( pNtk, pObj, i )
            Abc_ObjSetXsim( pObj, XVSX );
        Abc_NtkForEachLatch( pNtk, pObj, i )
            Abc_ObjSetXsim( Abc_ObjFanout0(pObj), Abc_LatchInit(pObj) );
    }
    else
    {
        Abc_NtkForEachPi( pNtk, pObj, i )
            Abc_ObjSetXsim( pObj, Abc_XsimRand2() );
        Abc_NtkForEachLatch( pNtk, pObj, i )
            Abc_ObjSetXsim( Abc_ObjFanout0(pObj), XVSX );
    }
    // simulate and print the result
    fprintf( stdout, "Frame : Inputs : Latches : Outputs\n" );
    for ( f = 0; f < nFrames; f++ )
    {
        Abc_AigForEachAnd( pNtk, pObj, i )
            Abc_ObjSetXsim( pObj, Abc_XsimAnd(Abc_ObjGetXsimFanin0(pObj), Abc_ObjGetXsimFanin1(pObj)) );
        Abc_NtkForEachCo( pNtk, pObj, i )
            Abc_ObjSetXsim( pObj, Abc_ObjGetXsimFanin0(pObj) );
        // print out
        fprintf( stdout, "%2d : ", f );
        Abc_NtkForEachPi( pNtk, pObj, i )
            Abc_XsimPrint( stdout, Abc_ObjGetXsim(pObj) );
        fprintf( stdout, " : " );
        Abc_NtkForEachLatch( pNtk, pObj, i )
            Abc_XsimPrint( stdout, Abc_ObjGetXsim(Abc_ObjFanout0(pObj)) );
        fprintf( stdout, " : " );
        Abc_NtkForEachPo( pNtk, pObj, i )
            Abc_XsimPrint( stdout, Abc_ObjGetXsim(pObj) );
        fprintf( stdout, "\n" );
        // assign input values
        if ( fInputs )
            Abc_NtkForEachPi( pNtk, pObj, i )
                Abc_ObjSetXsim( pObj, XVSX );
        else
            Abc_NtkForEachPi( pNtk, pObj, i )
                Abc_ObjSetXsim( pObj, Abc_XsimRand2() );
        // transfer the latch values
        Abc_NtkForEachLatch( pNtk, pObj, i )
            Abc_ObjSetXsim( Abc_ObjFanout0(pObj), Abc_ObjGetXsim(Abc_ObjFanin0(pObj)) );
    }
}

/**Function*************************************************************

  Synopsis    [Cycles the circuit to create a new initial state.]

  Description [Simulates the circuit with random input for the given 
  number of timeframes to get a better initial state.]
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void Abc_NtkCycleInitState( Abc_Ntk_t * pNtk, int nFrames, int fVerbose )
{
    Abc_Obj_t * pObj;
    int i, f;
    assert( Abc_NtkIsStrash(pNtk) );
    srand( 0x12341234 );
    // initialize the values
    Abc_ObjSetXsim( Abc_AigConst1(pNtk), XVS1 );
    Abc_NtkForEachPi( pNtk, pObj, i )
        Abc_ObjSetXsim( pObj, Abc_XsimRand2() );
    Abc_NtkForEachLatch( pNtk, pObj, i )
        Abc_ObjSetXsim( Abc_ObjFanout0(pObj), Abc_LatchIsInit1(pObj)? XVS1 : XVS0 );
    // simulate for the given number of timeframes
    for ( f = 0; f < nFrames; f++ )
    {
        Abc_AigForEachAnd( pNtk, pObj, i )
            Abc_ObjSetXsim( pObj, Abc_XsimAnd(Abc_ObjGetXsimFanin0(pObj), Abc_ObjGetXsimFanin1(pObj)) );
        Abc_NtkForEachCo( pNtk, pObj, i )
            Abc_ObjSetXsim( pObj, Abc_ObjGetXsimFanin0(pObj) );
        // assign input values
        Abc_NtkForEachPi( pNtk, pObj, i )
            Abc_ObjSetXsim( pObj, Abc_XsimRand2() );
        // transfer the latch values
        Abc_NtkForEachLatch( pNtk, pObj, i )
            Abc_ObjSetXsim( Abc_ObjFanout0(pObj), Abc_ObjGetXsim(Abc_ObjFanin0(pObj)) );
    }
    // set the final values
    Abc_NtkForEachLatch( pNtk, pObj, i )
        pObj->pData = (void *)Abc_ObjGetXsim(Abc_ObjFanout0(pObj));
}

///////////////////////////////////////////////////////////////////////
///                       END OF FILE                                ///
////////////////////////////////////////////////////////////////////////


