sswLcorr.c

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

  FileName    [sswLcorr.c]

  SystemName  [ABC: Logic synthesis and verification system.]

  PackageName [Inductive prover with constraints.]

  Synopsis    [Latch correspondence.]

  Author      [Alan Mishchenko]
  
  Affiliation [UC Berkeley]

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

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

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

#include "sswInt.h"
//#include "bar.h"

ABC_NAMESPACE_IMPL_START


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

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

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

  Synopsis    [Tranfers simulation information from FRAIG to AIG.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void Ssw_ManSweepTransfer( Ssw_Man_t * p )
{
    Aig_Obj_t * pObj, * pObjFraig;
    unsigned * pInfo;
    int i;
    // transfer simulation information
    Aig_ManForEachPi( p->pAig, pObj, i )
    {
        pObjFraig = Ssw_ObjFrame( p, pObj, 0 );
        if ( pObjFraig == Aig_ManConst0(p->pFrames) )
        {
            Ssw_SmlObjAssignConst( p->pSml, pObj, 0, 0 );
            continue;
        }
        assert( !Aig_IsComplement(pObjFraig) );
        assert( Aig_ObjIsPi(pObjFraig) );
        pInfo = (unsigned *)Vec_PtrEntry( p->vSimInfo, Aig_ObjPioNum(pObjFraig) );
        Ssw_SmlObjSetWord( p->pSml, pObj, pInfo[0], 0, 0 );
    }
}

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

  Synopsis    [Performs one round of simulation with counter-examples.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
int Ssw_ManSweepResimulate( Ssw_Man_t * p )
{
    int RetValue1, RetValue2, clk = clock();
    // transfer PI simulation information from storage
    Ssw_ManSweepTransfer( p );
    // simulate internal nodes
    Ssw_SmlSimulateOneFrame( p->pSml );
    // check equivalence classes
    RetValue1 = Ssw_ClassesRefineConst1( p->ppClasses, 1 );
    RetValue2 = Ssw_ClassesRefine( p->ppClasses, 1 );
    // prepare simulation info for the next round
    Vec_PtrCleanSimInfo( p->vSimInfo, 0, 1 );
    p->nPatterns = 0;
    p->nSimRounds++;
p->timeSimSat += clock() - clk;
    return RetValue1 > 0 || RetValue2 > 0;
}

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

  Synopsis    [Saves one counter-example into internal storage.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void Ssw_SmlAddPattern( Ssw_Man_t * p, Aig_Obj_t * pRepr, Aig_Obj_t * pCand )
{
    Aig_Obj_t * pObj;
    unsigned * pInfo;
    int i, nVarNum, Value;
    Vec_PtrForEachEntry( Aig_Obj_t *, p->pMSat->vUsedPis, pObj, i )
    {
        nVarNum = Ssw_ObjSatNum( p->pMSat, pObj );
        assert( nVarNum > 0 );
        Value = sat_solver_var_value( p->pMSat->pSat, nVarNum );
        if ( Value == 0 )
            continue;
        pInfo = (unsigned *)Vec_PtrEntry( p->vSimInfo, Aig_ObjPioNum(pObj) );
        Abc_InfoSetBit( pInfo, p->nPatterns );
    }
}

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

  Synopsis    [Builds fraiged logic cone of the node.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void Ssw_ManBuildCone_rec( Ssw_Man_t * p, Aig_Obj_t * pObj )
{
    Aig_Obj_t * pObjNew;
    assert( !Aig_IsComplement(pObj) );
    if ( Ssw_ObjFrame( p, pObj, 0 ) )
        return;
    assert( Aig_ObjIsNode(pObj) );
    Ssw_ManBuildCone_rec( p, Aig_ObjFanin0(pObj) );
    Ssw_ManBuildCone_rec( p, Aig_ObjFanin1(pObj) );
    pObjNew = Aig_And( p->pFrames, Ssw_ObjChild0Fra(p, pObj, 0), Ssw_ObjChild1Fra(p, pObj, 0) );
    Ssw_ObjSetFrame( p, pObj, 0, pObjNew );
}

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

  Synopsis    [Recycles the SAT solver.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void Ssw_ManSweepLatchOne( Ssw_Man_t * p, Aig_Obj_t * pObjRepr, Aig_Obj_t * pObj )
{
    Aig_Obj_t * pObjFraig, * pObjReprFraig, * pObjLi;
    int RetValue, clk;
    assert( Aig_ObjIsPi(pObj) );
    assert( Aig_ObjIsPi(pObjRepr) || Aig_ObjIsConst1(pObjRepr) );
    // check if it makes sense to skip some calls
    if ( p->nCallsCount > 100 && p->nCallsUnsat < p->nCallsSat )
    {
        if ( ++p->nCallsDelta < 0 )
            return;
    }
    p->nCallsDelta = 0;
clk = clock();
    // get the fraiged node
    pObjLi = Saig_ObjLoToLi( p->pAig, pObj ); 
    Ssw_ManBuildCone_rec( p, Aig_ObjFanin0(pObjLi) );
    pObjFraig = Ssw_ObjChild0Fra( p, pObjLi, 0 );
    // get the fraiged representative
    if ( Aig_ObjIsPi(pObjRepr) )
    {
        pObjLi = Saig_ObjLoToLi( p->pAig, pObjRepr ); 
        Ssw_ManBuildCone_rec( p, Aig_ObjFanin0(pObjLi) );
        pObjReprFraig = Ssw_ObjChild0Fra( p, pObjLi, 0 );
    }
    else 
        pObjReprFraig = Ssw_ObjFrame( p, pObjRepr, 0 );
p->timeReduce += clock() - clk;
    // if the fraiged nodes are the same, return
    if ( Aig_Regular(pObjFraig) == Aig_Regular(pObjReprFraig) )
        return;
    p->nRecycleCalls++;
    p->nCallsCount++;

    // check equivalence of the two nodes
    if ( (pObj->fPhase == pObjRepr->fPhase) != (Aig_ObjPhaseReal(pObjFraig) == Aig_ObjPhaseReal(pObjReprFraig)) )
    {
        p->nPatterns++;
        p->nStrangers++;
        p->fRefined = 1;
    }
    else
    { 
        RetValue = Ssw_NodesAreEquiv( p, Aig_Regular(pObjReprFraig), Aig_Regular(pObjFraig) );
        if ( RetValue == 1 )  // proved equivalence
        {
            p->nCallsUnsat++;
            return;
        }
        if ( RetValue == -1 ) // timed out
        {
            Ssw_ClassesRemoveNode( p->ppClasses, pObj );
            p->nCallsUnsat++;
            p->fRefined = 1;
            return;
        }
        else // disproved equivalence
        {       
            Ssw_SmlAddPattern( p, pObjRepr, pObj );
            p->nPatterns++;
            p->nCallsSat++;
            p->fRefined = 1;
        }
    }
}

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

  Synopsis    [Performs one iteration of sweeping latches.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
int Ssw_ManSweepLatch( Ssw_Man_t * p )
{
//    Bar_Progress_t * pProgress = NULL;
    Vec_Ptr_t * vClass;
    Aig_Obj_t * pObj, * pRepr, * pTemp;
    int i, k;

    // start the timeframe
    p->pFrames = Aig_ManStart( Aig_ManObjNumMax(p->pAig) );
    // map constants and PIs
    Ssw_ObjSetFrame( p, Aig_ManConst1(p->pAig), 0, Aig_ManConst1(p->pFrames) );
    Saig_ManForEachPi( p->pAig, pObj, i )
        Ssw_ObjSetFrame( p, pObj, 0, Aig_ObjCreatePi(p->pFrames) );

    // implement equivalence classes
    Saig_ManForEachLo( p->pAig, pObj, i )
    {
        pRepr = Aig_ObjRepr( p->pAig, pObj );
        if ( pRepr == NULL )
        {
            pTemp = Aig_ObjCreatePi(p->pFrames);
            pTemp->pData = pObj;
        }
        else
            pTemp = Aig_NotCond( Ssw_ObjFrame(p, pRepr, 0), pRepr->fPhase ^ pObj->fPhase );
        Ssw_ObjSetFrame( p, pObj, 0, pTemp );
    }
    Aig_ManSetPioNumbers( p->pFrames );

    // prepare simulation info
    assert( p->vSimInfo == NULL );
    p->vSimInfo = Vec_PtrAllocSimInfo( Aig_ManPiNum(p->pFrames), 1 );
    Vec_PtrCleanSimInfo( p->vSimInfo, 0, 1 );

    // go through the registers
//    if ( p->pPars->fVerbose )
//        pProgress = Bar_ProgressStart( stdout, Aig_ManRegNum(p->pAig) );
    vClass = Vec_PtrAlloc( 100 );
    p->fRefined = 0;
    p->nCallsCount = p->nCallsSat = p->nCallsUnsat = 0;
    Saig_ManForEachLo( p->pAig, pObj, i )
    {
//        if ( p->pPars->fVerbose )
//            Bar_ProgressUpdate( pProgress, i, NULL );
        // consider the case of constant candidate
        if ( Ssw_ObjIsConst1Cand( p->pAig, pObj ) )
            Ssw_ManSweepLatchOne( p, Aig_ManConst1(p->pAig), pObj );
        else
        {
            // consider the case of equivalence class
            Ssw_ClassesCollectClass( p->ppClasses, pObj, vClass );
            if ( Vec_PtrSize(vClass) == 0 )
                continue;
            // try to prove equivalences in this class
            Vec_PtrForEachEntry( Aig_Obj_t *, vClass, pTemp, k )
                if ( Aig_ObjRepr(p->pAig, pTemp) == pObj )
                {
                    Ssw_ManSweepLatchOne( p, pObj, pTemp );
                    if ( p->nPatterns == 32 )
                        break;
                }
        }
        // resimulate
        if ( p->nPatterns == 32 )
            Ssw_ManSweepResimulate( p );
        // attempt recycling the SAT solver
        if ( p->pPars->nSatVarMax && 
             p->pMSat->nSatVars > p->pPars->nSatVarMax &&
             p->nRecycleCalls > p->pPars->nRecycleCalls )
        {
            p->nVarsMax  = Abc_MaxInt( p->nVarsMax,  p->pMSat->nSatVars );
            p->nCallsMax = Abc_MaxInt( p->nCallsMax, p->pMSat->nSolverCalls );
            Ssw_SatStop( p->pMSat );
            p->pMSat = Ssw_SatStart( 0 );
            p->nRecycles++;
            p->nRecycleCalls = 0;
        }
    }
//    ABC_PRT( "reduce", p->timeReduce );
//    Aig_TableProfile( p->pFrames );
//    printf( "And gates = %d\n", Aig_ManNodeNum(p->pFrames) );
    // resimulate
    if ( p->nPatterns > 0 )
        Ssw_ManSweepResimulate( p );
    // cleanup
    Vec_PtrFree( vClass );
//    if ( p->pPars->fVerbose )
//        Bar_ProgressStop( pProgress );

    // cleanup
//    Ssw_ClassesCheck( p->ppClasses );
    return p->fRefined;
}

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


ABC_NAMESPACE_IMPL_END