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

  FileName    [cecCec.c]

  SystemName  [ABC: Logic synthesis and verification system.]

  PackageName [Combinational equivalence checking.]

  Synopsis    [Integrated combinatinal equivalence checker.]

  Author      [Alan Mishchenko]
  
  Affiliation [UC Berkeley]

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

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

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

#include "cecInt.h"
#include "proof/fra/fra.h"
#include "aig/gia/giaAig.h"
#include "misc/extra/extra.h"
#include "sat/cnf/cnf.h"

ABC_NAMESPACE_IMPL_START


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

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

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

  Synopsis    [Saves the input pattern with the given number.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void Cec_ManTransformPattern( Gia_Man_t * p, int iOut, int * pValues )
{
    int i;
    assert( p->pCexComb == NULL );
    p->pCexComb = Abc_CexAlloc( 0, Gia_ManCiNum(p), 1 );
    p->pCexComb->iPo = iOut;
    for ( i = 0; i < Gia_ManCiNum(p); i++ )
        if ( pValues && pValues[i] )
            Abc_InfoSetBit( p->pCexComb->pData, i );
}

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

  Synopsis    [Interface to the old CEC engine]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
int Cec_ManVerifyOld( Gia_Man_t * pMiter, int fVerbose, int * piOutFail, abctime clkTotal )
{
//    extern int Fra_FraigCec( Aig_Man_t ** ppAig, int nConfLimit, int fVerbose );
    extern int Ssw_SecCexResimulate( Aig_Man_t * p, int * pModel, int * pnOutputs );
    Gia_Man_t * pTemp = Gia_ManTransformMiter( pMiter );
    Aig_Man_t * pMiterCec = Gia_ManToAig( pTemp, 0 );
    int RetValue, iOut, nOuts;
    if ( piOutFail )
        *piOutFail = -1;
    Gia_ManStop( pTemp );
    // run CEC on this miter
    RetValue = Fra_FraigCec( &pMiterCec, 10000000, fVerbose );
    // report the miter
    if ( RetValue == 1 )
    {
        Abc_Print( 1, "Networks are equivalent.   " );
        Abc_PrintTime( 1, "Time", Abc_Clock() - clkTotal );
    }
    else if ( RetValue == 0 )
    {
        Abc_Print( 1, "Networks are NOT EQUIVALENT.   " );
        Abc_PrintTime( 1, "Time", Abc_Clock() - clkTotal );
        if ( pMiterCec->pData == NULL )
            Abc_Print( 1, "Counter-example is not available.\n" );
        else
        {
            iOut = Ssw_SecCexResimulate( pMiterCec, (int *)pMiterCec->pData, &nOuts );
            if ( iOut == -1 )
                Abc_Print( 1, "Counter-example verification has failed.\n" );
            else 
            {
//                Aig_Obj_t * pObj = Aig_ManCo(pMiterCec, iOut);
//                Aig_Obj_t * pFan = Aig_ObjFanin0(pObj);
                Abc_Print( 1, "Primary output %d has failed", iOut );
                if ( nOuts-1 >= 0 )
                    Abc_Print( 1, ", along with other %d incorrect outputs", nOuts-1 );
                Abc_Print( 1, ".\n" );
                if ( piOutFail )
                    *piOutFail = iOut;
            }
            Cec_ManTransformPattern( pMiter, iOut, (int *)pMiterCec->pData );
        }
    }
    else
    {
        Abc_Print( 1, "Networks are UNDECIDED.   " );
        Abc_PrintTime( 1, "Time", Abc_Clock() - clkTotal );
    }
    fflush( stdout );
    Aig_ManStop( pMiterCec );
    return RetValue;
}

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

  Synopsis    []

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
int Cec_ManHandleSpecialCases( Gia_Man_t * p, Cec_ParCec_t * pPars )
{
    Gia_Obj_t * pObj1, * pObj2;
    Gia_Obj_t * pDri1, * pDri2;
    int i;
    abctime clk = Abc_Clock();
    Gia_ManSetPhase( p );
    Gia_ManForEachPo( p, pObj1, i )
    {
        pObj2 = Gia_ManPo( p, ++i );
        // check if they different on all-0 pattern
        // (for example, when they have the same driver but complemented)
        if ( Gia_ObjPhase(pObj1) != Gia_ObjPhase(pObj2) )
        {
            Abc_Print( 1, "Networks are NOT EQUIVALENT. Output %d trivially differs (different phase).  ", i/2 );
            Abc_PrintTime( 1, "Time", Abc_Clock() - clk );
            pPars->iOutFail = i/2;
            Cec_ManTransformPattern( p, i/2, NULL );
            return 0;
        }
        // get the drivers
        pDri1 = Gia_ObjFanin0(pObj1);
        pDri2 = Gia_ObjFanin0(pObj2);
        // drivers are different PIs
        if ( Gia_ObjIsPi(p, pDri1) && Gia_ObjIsPi(p, pDri2) && pDri1 != pDri2 )
        {
            Abc_Print( 1, "Networks are NOT EQUIVALENT. Output %d trivially differs (different PIs).  ", i/2 );
            Abc_PrintTime( 1, "Time", Abc_Clock() - clk );
            pPars->iOutFail = i/2;
            Cec_ManTransformPattern( p, i/2, NULL );
            // if their compl attributes are the same - one should be complemented
            assert( Gia_ObjFaninC0(pObj1) == Gia_ObjFaninC0(pObj2) );
            Abc_InfoSetBit( p->pCexComb->pData, Gia_ObjCioId(pDri1) );
            return 0;
        }
        // one of the drivers is a PI; another is a constant 0
        if ( (Gia_ObjIsPi(p, pDri1) && Gia_ObjIsConst0(pDri2)) || 
             (Gia_ObjIsPi(p, pDri2) && Gia_ObjIsConst0(pDri1)) )
        {
            Abc_Print( 1, "Networks are NOT EQUIVALENT. Output %d trivially differs (PI vs. constant).  ", i/2 );
            Abc_PrintTime( 1, "Time", Abc_Clock() - clk );
            pPars->iOutFail = i/2;
            Cec_ManTransformPattern( p, i/2, NULL );
            // the compl attributes are the same - the PI should be complemented
            assert( Gia_ObjFaninC0(pObj1) == Gia_ObjFaninC0(pObj2) );
            if ( Gia_ObjIsPi(p, pDri1) )
                Abc_InfoSetBit( p->pCexComb->pData, Gia_ObjCioId(pDri1) );
            else
                Abc_InfoSetBit( p->pCexComb->pData, Gia_ObjCioId(pDri2) );
            return 0;
        }
    }
    if ( Gia_ManAndNum(p) == 0 )
    {
        Abc_Print( 1, "Networks are equivalent.  " );
        Abc_PrintTime( 1, "Time", Abc_Clock() - clk );
        return 1;
    }
    return -1;
}

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

  Synopsis    [Performs naive checking.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
int Cec_ManVerifyNaive( Gia_Man_t * p, Cec_ParCec_t * pPars )
{
    extern Cnf_Dat_t * Mf_ManGenerateCnf( Gia_Man_t * pGia, int nLutSize, int fCnfObjIds, int fAddOrCla, int fVerbose );
    Cnf_Dat_t * pCnf = Mf_ManGenerateCnf( p, 8, 0, 0, 0 );
    sat_solver * pSat = (sat_solver *)Cnf_DataWriteIntoSolver( pCnf, 1, 0 );
    Gia_Obj_t * pObj0, * pObj1;
    abctime clkStart = Abc_Clock();
    int nPairs = Gia_ManPoNum(p)/2;
    int nUnsats = 0, nSats = 0, nUndecs = 0, nTrivs = 0;
    int i, iVar0, iVar1, pLits[2], status, RetValue;
    ProgressBar * pProgress = Extra_ProgressBarStart( stdout, nPairs );
    assert( Gia_ManPoNum(p) % 2 == 0 );
    for ( i = 0; i < nPairs; i++ )
    {
        if ( (i & 0xFF) == 0 )
            Extra_ProgressBarUpdate( pProgress, i, NULL );
        pObj0 = Gia_ManPo(p, 2*i);
        pObj1 = Gia_ManPo(p, 2*i+1);
        if ( Gia_ObjChild0(pObj0) == Gia_ObjChild0(pObj1) )
        {
            nUnsats++;
            nTrivs++;
            continue;
        }
        if ( pPars->TimeLimit && (Abc_Clock() - clkStart)/CLOCKS_PER_SEC >= pPars->TimeLimit )
        {
            printf( "Timeout (%d sec) is reached.\n", pPars->TimeLimit );
            nUndecs = nPairs - nUnsats - nSats;
            break;
        }
        iVar0 = pCnf->pVarNums[ Gia_ObjId(p, pObj0) ];
        iVar1 = pCnf->pVarNums[ Gia_ObjId(p, pObj1) ];
        assert( iVar0 >= 0 && iVar1 >= 0 );
        pLits[0] = Abc_Var2Lit( iVar0, 0 );
        pLits[1] = Abc_Var2Lit( iVar1, 0 );
        // check direct
        pLits[0] = lit_neg(pLits[0]);
        status = sat_solver_solve( pSat, pLits, pLits + 2, pPars->nBTLimit, 0, 0, 0 );
        if ( status == l_False )
        {
            pLits[0] = lit_neg( pLits[0] );
            pLits[1] = lit_neg( pLits[1] );
            RetValue = sat_solver_addclause( pSat, pLits, pLits + 2 );
            assert( RetValue );
        }
        else if ( status == l_True )
        {
            printf( "Output %d is SAT.\n", i );
            nSats++;
            continue;
        }
        else
        {
            nUndecs++;
            continue;
        }
        // check inverse
        status = sat_solver_solve( pSat, pLits, pLits + 2, pPars->nBTLimit, 0, 0, 0 );
        if ( status == l_False )
        {
            pLits[0] = lit_neg( pLits[0] );
            pLits[1] = lit_neg( pLits[1] );
            RetValue = sat_solver_addclause( pSat, pLits, pLits + 2 );
            assert( RetValue );
        }
        else if ( status == l_True )
        {
            printf( "Output %d is SAT.\n", i );
            nSats++;
            continue;
        }
        else
        {
            nUndecs++;
            continue;
        }
        nUnsats++;
    }
    Extra_ProgressBarStop( pProgress );
    printf( "UNSAT = %6d.  SAT = %6d.   UNDEC = %6d.  Trivial = %6d.  ", nUnsats, nSats, nUndecs, nTrivs );
    Abc_PrintTime( 1, "Time", Abc_Clock() - clkStart );
    Cnf_DataFree( pCnf );
    sat_solver_delete( pSat );
    if ( nSats )
        return 0;
    if ( nUndecs )
        return -1;
    return 1;
}

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

  Synopsis    [New CEC engine.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
int Cec_ManVerify( Gia_Man_t * pInit, Cec_ParCec_t * pPars )
{
    int fDumpUndecided = 0;
    Cec_ParFra_t ParsFra, * pParsFra = &ParsFra;
    Gia_Man_t * p, * pNew;
    int RetValue;
    abctime clk = Abc_Clock();
    abctime clkTotal = Abc_Clock();
    // consider special cases:
    // 1) (SAT) a pair of POs have different value under all-0 pattern
    // 2) (SAT) a pair of POs has different PI/Const drivers
    // 3) (UNSAT) 1-2 do not hold and there is no nodes
    RetValue = Cec_ManHandleSpecialCases( pInit, pPars );
    if ( RetValue == 0 || RetValue == 1 )
        return RetValue;
    // preprocess 
    p = Gia_ManDup( pInit );
    Gia_ManEquivFixOutputPairs( p );
    p = Gia_ManCleanup( pNew = p );
    Gia_ManStop( pNew );
    if ( pPars->fNaive )
    {
        RetValue = Cec_ManVerifyNaive( p, pPars );
        Gia_ManStop( p );
        return RetValue;
    }
    // sweep for equivalences
    Cec_ManFraSetDefaultParams( pParsFra );
    pParsFra->nItersMax    = 1000;
    pParsFra->nBTLimit     = pPars->nBTLimit;
    pParsFra->TimeLimit    = pPars->TimeLimit;
    pParsFra->fVerbose     = pPars->fVerbose;
    pParsFra->fCheckMiter  = 1;
    pParsFra->fDualOut     = 1;
    pNew = Cec_ManSatSweeping( p, pParsFra );
    pPars->iOutFail = pParsFra->iOutFail;
    // update
    pInit->pCexComb = p->pCexComb; p->pCexComb = NULL;
    Gia_ManStop( p );
    p = pInit;
    // continue
    if ( pNew == NULL )
    {
        if ( p->pCexComb != NULL )
        {
            if ( p->pCexComb && !Gia_ManVerifyCex( p, p->pCexComb, 1 ) )
                Abc_Print( 1, "Counter-example simulation has failed.\n" );
            Abc_Print( 1, "Networks are NOT EQUIVALENT.  " );
            Abc_PrintTime( 1, "Time", Abc_Clock() - clk );
            return 0;
        }
        p = Gia_ManDup( pInit );
        Gia_ManEquivFixOutputPairs( p );
        p = Gia_ManCleanup( pNew = p );
        Gia_ManStop( pNew );
        pNew = p;
    }
    if ( pPars->fVerbose )
    {
        Abc_Print( 1, "Networks are UNDECIDED after the new CEC engine.  " );
        Abc_PrintTime( 1, "Time", Abc_Clock() - clk );
    }
    if ( fDumpUndecided )
    {
        ABC_FREE( pNew->pReprs );
        ABC_FREE( pNew->pNexts );
        Gia_AigerWrite( pNew, "gia_cec_undecided.aig", 0, 0 );
        Abc_Print( 1, "The result is written into file \"%s\".\n", "gia_cec_undecided.aig" );
    }
    if ( pPars->TimeLimit && (Abc_Clock() - clkTotal)/CLOCKS_PER_SEC >= pPars->TimeLimit )
    {
        Gia_ManStop( pNew );
        return -1;
    }
    // call other solver
    if ( pPars->fVerbose )
        Abc_Print( 1, "Calling the old CEC engine.\n" );
    fflush( stdout );
    RetValue = Cec_ManVerifyOld( pNew, pPars->fVerbose, &pPars->iOutFail, clkTotal );
    p->pCexComb = pNew->pCexComb; pNew->pCexComb = NULL;
    if ( p->pCexComb && !Gia_ManVerifyCex( p, p->pCexComb, 1 ) )
        Abc_Print( 1, "Counter-example simulation has failed.\n" );
    Gia_ManStop( pNew );
    return RetValue;
}

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

  Synopsis    [New CEC engine applied to two circuits.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
int Cec_ManVerifyTwo( Gia_Man_t * p0, Gia_Man_t * p1, int fVerbose )
{
    Cec_ParCec_t ParsCec, * pPars = &ParsCec;
    Gia_Man_t * pMiter;
    int RetValue;
    Cec_ManCecSetDefaultParams( pPars );
    pPars->fVerbose = fVerbose;
    pMiter = Gia_ManMiter( p0, p1, 0, 1, 0, 0, pPars->fVerbose );
    if ( pMiter == NULL )
        return -1;
    RetValue = Cec_ManVerify( pMiter, pPars );
    p0->pCexComb = pMiter->pCexComb; pMiter->pCexComb = NULL;
    Gia_ManStop( pMiter );
    return RetValue;
}

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

  Synopsis    [New CEC engine applied to two circuits.]

  Description [Returns 1 if equivalent, 0 if counter-example, -1 if undecided.
  Counter-example is returned in the first manager as pAig0->pSeqModel.
  The format is given in Abc_Cex_t (file "abc\src\aig\gia\gia.h").]
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
int Cec_ManVerifyTwoAigs( Aig_Man_t * pAig0, Aig_Man_t * pAig1, int fVerbose )
{
    Gia_Man_t * p0, * p1, * pTemp;
    int RetValue;

    p0 = Gia_ManFromAig( pAig0 );
    p0 = Gia_ManCleanup( pTemp = p0 );
    Gia_ManStop( pTemp );

    p1 = Gia_ManFromAig( pAig1 );
    p1 = Gia_ManCleanup( pTemp = p1 );
    Gia_ManStop( pTemp );

    RetValue = Cec_ManVerifyTwo( p0, p1, fVerbose );
    pAig0->pSeqModel = p0->pCexComb; p0->pCexComb = NULL;
    Gia_ManStop( p0 );
    Gia_ManStop( p1 );
    return RetValue;
}

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

  Synopsis    [Implementation of new signal correspodence.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
Aig_Man_t * Cec_LatchCorrespondence( Aig_Man_t * pAig, int nConfs, int fUseCSat )
{
    Gia_Man_t * pGia;
    Cec_ParCor_t CorPars, * pCorPars = &CorPars;
    Cec_ManCorSetDefaultParams( pCorPars );
    pCorPars->fLatchCorr = 1;
    pCorPars->fUseCSat   = fUseCSat;
    pCorPars->nBTLimit   = nConfs;
    pGia = Gia_ManFromAigSimple( pAig );
    Cec_ManLSCorrespondenceClasses( pGia, pCorPars );
    Gia_ManReprToAigRepr( pAig, pGia );
    Gia_ManStop( pGia );
    return Aig_ManDupSimple( pAig );
}

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

  Synopsis    [Implementation of new signal correspodence.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
Aig_Man_t * Cec_SignalCorrespondence( Aig_Man_t * pAig, int nConfs, int fUseCSat )
{
    Gia_Man_t * pGia;
    Cec_ParCor_t CorPars, * pCorPars = &CorPars;
    Cec_ManCorSetDefaultParams( pCorPars );
    pCorPars->fUseCSat  = fUseCSat;
    pCorPars->nBTLimit  = nConfs;
    pGia = Gia_ManFromAigSimple( pAig );
    Cec_ManLSCorrespondenceClasses( pGia, pCorPars );
    Gia_ManReprToAigRepr( pAig, pGia );
    Gia_ManStop( pGia );
    return Aig_ManDupSimple( pAig );
}

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

  Synopsis    [Implementation of fraiging.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
Aig_Man_t * Cec_FraigCombinational( Aig_Man_t * pAig, int nConfs, int fVerbose )
{
    Gia_Man_t * pGia;
    Cec_ParFra_t FraPars, * pFraPars = &FraPars;
    Cec_ManFraSetDefaultParams( pFraPars );
    pFraPars->fSatSweeping = 1;
    pFraPars->nBTLimit  = nConfs;
    pFraPars->nItersMax = 20;
    pFraPars->fVerbose  = fVerbose;
    pGia = Gia_ManFromAigSimple( pAig );
    Cec_ManSatSweeping( pGia, pFraPars );
    Gia_ManReprToAigRepr( pAig, pGia );
    Gia_ManStop( pGia );
    return Aig_ManDupSimple( pAig );
}

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


ABC_NAMESPACE_IMPL_END

