sswFilter.c

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

  FileName    [sswConstr.c]

  SystemName  [ABC: Logic synthesis and verification system.]

  PackageName [Inductive prover with constraints.]

  Synopsis    [One round of SAT sweeping.]

  Author      [Alan Mishchenko]
  
  Affiliation [UC Berkeley]

  Date        [Ver. 1.0. Started - September 1, 2008.]

  Revision    [$Id: sswConstr.c,v 1.00 2008/09/01 00:00:00 alanmi Exp $]

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

#include "sswInt.h"
#include "aig/gia/giaAig.h"

ABC_NAMESPACE_IMPL_START


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

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

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

  Synopsis    [Performs fraiging for one node.]

  Description [Returns the fraiged node.]
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void Ssw_ManRefineByFilterSim( Ssw_Man_t * p, int nFrames )
{
    Aig_Obj_t * pObj, * pObjLi;
    int f, i, RetValue1, RetValue2;
    assert( nFrames > 0 );
    // assign register outputs
    Saig_ManForEachLi( p->pAig, pObj, i )
        pObj->fMarkB = Abc_InfoHasBit( p->pPatWords, Saig_ManPiNum(p->pAig) + i );
    // simulate the timeframes
    for ( f = 0; f < nFrames; f++ )
    {
        // set the PI simulation information
        Aig_ManConst1(p->pAig)->fMarkB = 1;
        Saig_ManForEachPi( p->pAig, pObj, i )
            pObj->fMarkB = 0;
        Saig_ManForEachLiLo( p->pAig, pObjLi, pObj, i )
            pObj->fMarkB = pObjLi->fMarkB;
        // simulate internal nodes
        Aig_ManForEachNode( p->pAig, pObj, i )
            pObj->fMarkB = ( Aig_ObjFanin0(pObj)->fMarkB ^ Aig_ObjFaninC0(pObj) )
                         & ( Aig_ObjFanin1(pObj)->fMarkB ^ Aig_ObjFaninC1(pObj) );
        // assign the COs
        Aig_ManForEachCo( p->pAig, pObj, i )
            pObj->fMarkB = ( Aig_ObjFanin0(pObj)->fMarkB ^ Aig_ObjFaninC0(pObj) );
        // transfer
        if ( f == 0 )
        { // copy markB into phase
            Aig_ManForEachObj( p->pAig, pObj, i )
                pObj->fPhase = pObj->fMarkB;
        }
        else
        { // refine classes
            RetValue1 = Ssw_ClassesRefineConst1( p->ppClasses, 0 );
            RetValue2 = Ssw_ClassesRefine( p->ppClasses, 0 );
        }
    }
}


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

  Synopsis    [Performs fraiging for one node.]

  Description [Returns the fraiged node.]

  SideEffects []

  SeeAlso     []

***********************************************************************/
void Ssw_ManRollForward( Ssw_Man_t * p, int nFrames )
{
    Aig_Obj_t * pObj, * pObjLi;
    int f, i;
    assert( nFrames > 0 );
    // assign register outputs
    Saig_ManForEachLi( p->pAig, pObj, i )
        pObj->fMarkB = Abc_InfoHasBit( p->pPatWords, Saig_ManPiNum(p->pAig) + i );
    // simulate the timeframes
    for ( f = 0; f < nFrames; f++ )
    {
        // set the PI simulation information
        Aig_ManConst1(p->pAig)->fMarkB = 1;
        Saig_ManForEachPi( p->pAig, pObj, i )
            pObj->fMarkB = Aig_ManRandom(0) & 1;
        Saig_ManForEachLiLo( p->pAig, pObjLi, pObj, i )
            pObj->fMarkB = pObjLi->fMarkB;
        // simulate internal nodes
        Aig_ManForEachNode( p->pAig, pObj, i )
            pObj->fMarkB = ( Aig_ObjFanin0(pObj)->fMarkB ^ Aig_ObjFaninC0(pObj) )
                         & ( Aig_ObjFanin1(pObj)->fMarkB ^ Aig_ObjFaninC1(pObj) );
        // assign the COs
        Aig_ManForEachCo( p->pAig, pObj, i )
            pObj->fMarkB = ( Aig_ObjFanin0(pObj)->fMarkB ^ Aig_ObjFaninC0(pObj) );
    }
    // record the new pattern
    Saig_ManForEachLi( p->pAig, pObj, i )
        if ( pObj->fMarkB ^ Abc_InfoHasBit(p->pPatWords, Saig_ManPiNum(p->pAig) + i) )
            Abc_InfoXorBit( p->pPatWords, Saig_ManPiNum(p->pAig) + i );
}

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

  Synopsis    [Performs fraiging for one node.]

  Description [Returns the fraiged node.]

  SideEffects []

  SeeAlso     []

***********************************************************************/
void Ssw_ManFindStartingState( Ssw_Man_t * p, Abc_Cex_t * pCex )
{
    Aig_Obj_t * pObj, * pObjLi;
    int f, i, iBit;
    // assign register outputs
    Saig_ManForEachLi( p->pAig, pObj, i )
        pObj->fMarkB = 0;
    // simulate the timeframes
    iBit = pCex->nRegs;
    for ( f = 0; f <= pCex->iFrame; f++ )
    {
        // set the PI simulation information
        Aig_ManConst1(p->pAig)->fMarkB = 1;
        Saig_ManForEachPi( p->pAig, pObj, i )
            pObj->fMarkB = Abc_InfoHasBit( pCex->pData, iBit++ );
        Saig_ManForEachLiLo( p->pAig, pObjLi, pObj, i )
            pObj->fMarkB = pObjLi->fMarkB;
        // simulate internal nodes
        Aig_ManForEachNode( p->pAig, pObj, i )
            pObj->fMarkB = ( Aig_ObjFanin0(pObj)->fMarkB ^ Aig_ObjFaninC0(pObj) )
                         & ( Aig_ObjFanin1(pObj)->fMarkB ^ Aig_ObjFaninC1(pObj) );
        // assign the COs
        Aig_ManForEachCo( p->pAig, pObj, i )
            pObj->fMarkB = ( Aig_ObjFanin0(pObj)->fMarkB ^ Aig_ObjFaninC0(pObj) );
    }
    assert( iBit == pCex->nBits );
    // check that the output failed as expected -- cannot check because it is not an SRM!
//    pObj = Aig_ManCo( p->pAig, pCex->iPo );
//    if ( pObj->fMarkB != 1 )
//        Abc_Print( 1, "The counter-example does not refine the output.\n" );
    // record the new pattern
    Saig_ManForEachLo( p->pAig, pObj, i )
        if ( pObj->fMarkB ^ Abc_InfoHasBit(p->pPatWords, Saig_ManPiNum(p->pAig) + i) )
            Abc_InfoXorBit( p->pPatWords, Saig_ManPiNum(p->pAig) + i );
}

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

  Synopsis    [Performs fraiging for one node.]

  Description [Returns the fraiged node.]
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
int Ssw_ManSweepNodeFilter( Ssw_Man_t * p, Aig_Obj_t * pObj, int f )
{
    Aig_Obj_t * pObjRepr, * pObjFraig, * pObjFraig2, * pObjReprFraig;
    int RetValue;
    // get representative of this class
    pObjRepr = Aig_ObjRepr( p->pAig, pObj );
    if ( pObjRepr == NULL )
        return 0;
    // get the fraiged node
    pObjFraig = Ssw_ObjFrame( p, pObj, f );
    // get the fraiged representative
    pObjReprFraig = Ssw_ObjFrame( p, pObjRepr, f );
    // check if constant 0 pattern distinquishes these nodes
    assert( pObjFraig != NULL && pObjReprFraig != NULL );
    assert( (pObj->fPhase == pObjRepr->fPhase) == (Aig_ObjPhaseReal(pObjFraig) == Aig_ObjPhaseReal(pObjReprFraig)) );
    // if the fraiged nodes are the same, return
    if ( Aig_Regular(pObjFraig) == Aig_Regular(pObjReprFraig) )
        return 0;
    // call equivalence checking
    if ( Aig_Regular(pObjFraig) != Aig_ManConst1(p->pFrames) )
        RetValue = Ssw_NodesAreEquiv( p, Aig_Regular(pObjReprFraig), Aig_Regular(pObjFraig) );
    else
        RetValue = Ssw_NodesAreEquiv( p, Aig_Regular(pObjFraig), Aig_Regular(pObjReprFraig) );
    if ( RetValue == 1 )  // proved equivalent
    {
        pObjFraig2 = Aig_NotCond( pObjReprFraig, pObj->fPhase ^ pObjRepr->fPhase );
        Ssw_ObjSetFrame( p, pObj, f, pObjFraig2 );
        return 0;
    }
    if ( RetValue == -1 ) // timed out
    {
//        Ssw_ClassesRemoveNode( p->ppClasses, pObj );
        return 1;
    }
    // disproved equivalence
    Ssw_SmlSavePatternAig( p, f );
    Ssw_ManResimulateBit( p, pObj, pObjRepr );
    assert( Aig_ObjRepr( p->pAig, pObj ) != pObjRepr );
    if ( Aig_ObjRepr( p->pAig, pObj ) == pObjRepr )
    {
        Abc_Print( 1, "Ssw_ManSweepNodeFilter(): Failed to refine representative.\n" );
    }
    return 0;
}

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

  Synopsis    [Performs fraiging for the internal nodes.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
Aig_Obj_t * Ssw_ManSweepBmcFilter_rec( Ssw_Man_t * p, Aig_Obj_t * pObj, int f )
{
    Aig_Obj_t * pObjNew, * pObjLi;
    pObjNew = Ssw_ObjFrame( p, pObj, f );
    if ( pObjNew )
        return pObjNew;
    assert( !Saig_ObjIsPi(p->pAig, pObj) );
    if ( Saig_ObjIsLo(p->pAig, pObj) )
    {
        assert( f > 0 );
        pObjLi  = Saig_ObjLoToLi( p->pAig, pObj );
        pObjNew = Ssw_ManSweepBmcFilter_rec( p, Aig_ObjFanin0(pObjLi), f-1 );
        pObjNew = Aig_NotCond( pObjNew, Aig_ObjFaninC0(pObjLi) );
    }
    else
    {
        assert( Aig_ObjIsNode(pObj) );
        Ssw_ManSweepBmcFilter_rec( p, Aig_ObjFanin0(pObj), f );
        Ssw_ManSweepBmcFilter_rec( p, Aig_ObjFanin1(pObj), f );
        pObjNew = Aig_And( p->pFrames, Ssw_ObjChild0Fra(p, pObj, f), Ssw_ObjChild1Fra(p, pObj, f) );
    }
    Ssw_ObjSetFrame( p, pObj, f, pObjNew );
    assert( pObjNew != NULL );
    return pObjNew;
}

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

  Synopsis    [Filter equivalence classes of nodes.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
int Ssw_ManSweepBmcFilter( Ssw_Man_t * p, int TimeLimit )
{
    Aig_Obj_t * pObj, * pObjNew, * pObjLi, * pObjLo;
    int f, f1, i;
    abctime clkTotal = Abc_Clock();
    // start initialized timeframes
    p->pFrames = Aig_ManStart( Aig_ManObjNumMax(p->pAig) * p->pPars->nFramesK );
    Saig_ManForEachLo( p->pAig, pObj, i )
    {
        if ( Abc_InfoHasBit( p->pPatWords, Saig_ManPiNum(p->pAig) + i ) )
        {
            Ssw_ObjSetFrame( p, pObj, 0, Aig_ManConst1(p->pFrames) );
//Abc_Print( 1, "1" );
        }
        else
        {
            Ssw_ObjSetFrame( p, pObj, 0, Aig_ManConst0(p->pFrames) );
//Abc_Print( 1, "0" );
        }
    }
//Abc_Print( 1, "\n" );

    // sweep internal nodes
    for ( f = 0; f < p->pPars->nFramesK; f++ )
    {
        // realloc mapping of timeframes
        if ( f == p->nFrames-1 )
        {
            Aig_Obj_t ** pNodeToFrames;
            pNodeToFrames = ABC_CALLOC( Aig_Obj_t *, Aig_ManObjNumMax(p->pAig) * 2 * p->nFrames );
            for ( f1 = 0; f1 < p->nFrames; f1++ )
            {
                Aig_ManForEachObj( p->pAig, pObj, i )
                    pNodeToFrames[2*p->nFrames*pObj->Id + f1] = Ssw_ObjFrame( p, pObj, f1 );
            }
            ABC_FREE( p->pNodeToFrames );
            p->pNodeToFrames = pNodeToFrames;
            p->nFrames *= 2;
        }
        // map constants and PIs
        Ssw_ObjSetFrame( p, Aig_ManConst1(p->pAig), f, Aig_ManConst1(p->pFrames) );
        Saig_ManForEachPi( p->pAig, pObj, i )
        {
            pObjNew = Aig_ObjCreateCi(p->pFrames);
            Ssw_ObjSetFrame( p, pObj, f, pObjNew );
        }
        // sweep internal nodes
        Aig_ManForEachNode( p->pAig, pObj, i )
        {
            pObjNew = Aig_And( p->pFrames, Ssw_ObjChild0Fra(p, pObj, f), Ssw_ObjChild1Fra(p, pObj, f) );
            Ssw_ObjSetFrame( p, pObj, f, pObjNew );
            if ( Ssw_ManSweepNodeFilter( p, pObj, f ) )
                break;
        }
        // printout
        if ( p->pPars->fVerbose )
        {
            Abc_Print( 1, "Frame %4d : ", f );
            Ssw_ClassesPrint( p->ppClasses, 0 );
        }
        if ( i < Vec_PtrSize(p->pAig->vObjs) )
        {
            if ( p->pPars->fVerbose )
                Abc_Print( 1, "Exceeded the resource limits (%d conflicts). Quitting...\n", p->pPars->nBTLimit );
            break;
        }
        // quit if this is the last timeframe
        if ( f == p->pPars->nFramesK - 1 )
        {
            if ( p->pPars->fVerbose )
                Abc_Print( 1, "Exceeded the time frame limit (%d time frames). Quitting...\n", p->pPars->nFramesK );
            break;
        }
        // check timeout
        if ( TimeLimit && ((float)TimeLimit <= (float)(Abc_Clock()-clkTotal)/(float)(CLOCKS_PER_SEC)) )
            break;
        // transfer latch input to the latch outputs 
        Aig_ManForEachCo( p->pAig, pObj, i )
            Ssw_ObjSetFrame( p, pObj, f, Ssw_ObjChild0Fra(p, pObj, f) );
        // build logic cones for register outputs
        Saig_ManForEachLiLo( p->pAig, pObjLi, pObjLo, i )
        {
            pObjNew = Ssw_ObjFrame( p, pObjLi, f );
            Ssw_ObjSetFrame( p, pObjLo, f+1, pObjNew );
            Ssw_CnfNodeAddToSolver( p->pMSat, Aig_Regular(pObjNew) );//
        }
    }
    // verify
//    Ssw_ClassesCheck( p->ppClasses );
    return 1;
}

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

  Synopsis    [Filter equivalence classes of nodes.]

  Description [Unrolls at most nFramesMax frames. Works with nConfMax
  conflicts until the first undefined SAT call. Verbose prints the message.]

  SideEffects []

  SeeAlso     []

***********************************************************************/
void Ssw_SignalFilter( Aig_Man_t * pAig, int nFramesMax, int nConfMax, int nRounds, int TimeLimit, int TimeLimit2, Abc_Cex_t * pCex, int fLatchOnly, int fVerbose )
{
    Ssw_Pars_t Pars, * pPars = &Pars;
    Ssw_Man_t * p;
    int r, TimeLimitPart;//, clkTotal = Abc_Clock();
    abctime nTimeToStop = TimeLimit ? TimeLimit * CLOCKS_PER_SEC + Abc_Clock(): 0;
    assert( Aig_ManRegNum(pAig) > 0 );
    assert( Aig_ManConstrNum(pAig) == 0 );
    // consider the case of empty AIG
    if ( Aig_ManNodeNum(pAig) == 0 )
        return;
    // reset random numbers
    Aig_ManRandom( 1 );
    // if parameters are not given, create them
    Ssw_ManSetDefaultParams( pPars = &Pars );
    pPars->nFramesK  = 3; //nFramesMax;
    pPars->nBTLimit  = nConfMax;
    pPars->TimeLimit = TimeLimit;
    pPars->fVerbose  = fVerbose;
    // start the induction manager
    p = Ssw_ManCreate( pAig, pPars );
    pPars->nFramesK  = nFramesMax;
    // create trivial equivalence classes with all nodes being candidates for constant 1
    if ( pAig->pReprs == NULL )
        p->ppClasses = Ssw_ClassesPrepareSimple( pAig, fLatchOnly, 0 );
    else
        p->ppClasses = Ssw_ClassesPrepareFromReprs( pAig );
    Ssw_ClassesSetData( p->ppClasses, NULL, NULL, Ssw_SmlObjIsConstBit, Ssw_SmlObjsAreEqualBit );
    assert( p->vInits == NULL );
    // compute starting state if needed
    if ( pCex )
        Ssw_ManFindStartingState( p, pCex );
    // refine classes using BMC
    for ( r = 0; r < nRounds; r++ )
    {
        if ( p->pPars->fVerbose )
            Abc_Print( 1, "Round %3d:\n", r );
        // start filtering equivalence classes
        Ssw_ManRefineByFilterSim( p, p->pPars->nFramesK );
        if ( Ssw_ClassesCand1Num(p->ppClasses) == 0 && Ssw_ClassesClassNum(p->ppClasses) == 0 )
        {
            Abc_Print( 1, "All equivalences are refined away.\n" );
            break;
        }
        // printout
        if ( p->pPars->fVerbose )
        {
            Abc_Print( 1, "Initial    : " );
            Ssw_ClassesPrint( p->ppClasses, 0 );
        }
        p->pMSat = Ssw_SatStart( 0 );
        TimeLimitPart = TimeLimit ? (nTimeToStop - Abc_Clock()) / CLOCKS_PER_SEC : 0;
        if ( TimeLimit2 )
        {
            if ( TimeLimitPart )
                TimeLimitPart = Abc_MinInt( TimeLimitPart, TimeLimit2 );
            else
                TimeLimitPart = TimeLimit2;
        }
        Ssw_ManSweepBmcFilter( p, TimeLimitPart );
        Ssw_SatStop( p->pMSat );
        p->pMSat = NULL;
        Ssw_ManCleanup( p );
        // simulate pattern forward
        Ssw_ManRollForward( p, p->pPars->nFramesK );
        // check timeout
        if ( TimeLimit && Abc_Clock() > nTimeToStop )
        {
            Abc_Print( 1, "Reached timeout (%d seconds).\n",  TimeLimit );
            break;
        }
    }
    // cleanup
    Aig_ManSetPhase( p->pAig );
    Aig_ManCleanMarkB( p->pAig );
    // cleanup
    pPars->fVerbose = 0;
    Ssw_ManStop( p );
}

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

  Synopsis    [Filter equivalence classes of nodes.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void Ssw_SignalFilterGia( Gia_Man_t * p, int nFramesMax, int nConfMax, int nRounds, int TimeLimit, int TimeLimit2, Abc_Cex_t * pCex, int fLatchOnly, int fVerbose )
{
    Aig_Man_t * pAig;
    pAig = Gia_ManToAigSimple( p );
    if ( p->pReprs != NULL )
    {
        Gia_ManReprToAigRepr2( pAig, p );
        ABC_FREE( p->pReprs );
        ABC_FREE( p->pNexts );
    }
    Ssw_SignalFilter( pAig, nFramesMax, nConfMax, nRounds, TimeLimit, TimeLimit2, pCex, fLatchOnly, fVerbose );
    Gia_ManReprFromAigRepr( pAig, p );
    Aig_ManStop( pAig );
}

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


ABC_NAMESPACE_IMPL_END