msatClause.c File Reference

#include "msatInt.h"

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Classes
struct	Msat_Clause_t_
	DECLARATIONS ///. More...

Functions
int	Msat_ClauseCreate (Msat_Solver_t *p, Msat_IntVec_t *vLits, int fLearned, Msat_Clause_t **pClause_out)
	FUNCTION DEFINITIONS ///.
void	Msat_ClauseFree (Msat_Solver_t *p, Msat_Clause_t *pC, int fRemoveWatched)
int	Msat_ClauseReadLearned (Msat_Clause_t *pC)
int	Msat_ClauseReadSize (Msat_Clause_t *pC)
int *	Msat_ClauseReadLits (Msat_Clause_t *pC)
int	Msat_ClauseReadMark (Msat_Clause_t *pC)
int	Msat_ClauseReadNum (Msat_Clause_t *pC)
int	Msat_ClauseReadTypeA (Msat_Clause_t *pC)
void	Msat_ClauseSetMark (Msat_Clause_t *pC, int fMark)
void	Msat_ClauseSetNum (Msat_Clause_t *pC, int Num)
void	Msat_ClauseSetTypeA (Msat_Clause_t *pC, int fTypeA)
int	Msat_ClauseIsLocked (Msat_Solver_t *p, Msat_Clause_t *pC)
float	Msat_ClauseReadActivity (Msat_Clause_t *pC)
void	Msat_ClauseWriteActivity (Msat_Clause_t *pC, float Num)
int	Msat_ClausePropagate (Msat_Clause_t *pC, Msat_Lit_t Lit, int *pAssigns, Msat_Lit_t *pLit_out)
int	Msat_ClauseSimplify (Msat_Clause_t *pC, int *pAssigns)
void	Msat_ClauseCalcReason (Msat_Solver_t *p, Msat_Clause_t *pC, Msat_Lit_t Lit, Msat_IntVec_t *vLits_out)
void	Msat_ClauseRemoveWatch (Msat_ClauseVec_t *vClauses, Msat_Clause_t *pC)
void	Msat_ClausePrint (Msat_Clause_t *pC)
void	Msat_ClauseWriteDimacs (FILE *pFile, Msat_Clause_t *pC, int fIncrement)
void	Msat_ClausePrintSymbols (Msat_Clause_t *pC)

Function Documentation

Msat_ClauseCalcReason()

void Msat_ClauseCalcReason	(	Msat_Solver_t *	p,
		Msat_Clause_t *	pC,
		Msat_Lit_t	Lit,
		Msat_IntVec_t *	vLits_out )

Function*************************************************************

Synopsis [Computes reason of conflict in the given clause.]

Description [If the literal is unassigned, finds the reason by complementing literals in the given cluase (pC). If the literal is assigned, makes sure that this literal is the first one in the clause and computes the complement of all other literals in the clause. Returns the reason in the given array (vLits_out). If the clause is learned, bumps its activity.]

SideEffects []

SeeAlso []

Definition at line 418 of file msatClause.c.

{
    int i;
    // clear the reason
    Msat_IntVecClear( vLits_out );
    assert( Lit == MSAT_LIT_UNASSIGNED || Lit == pC->pData[0] );
    for ( i = (Lit != MSAT_LIT_UNASSIGNED); i < (int)pC->nSize; i++ )
    {
        assert( Msat_SolverReadAssignsArray(p)[MSAT_LIT2VAR(pC->pData[i])] == MSAT_LITNOT(pC->pData[i]) );
        Msat_IntVecPush( vLits_out, MSAT_LITNOT(pC->pData[i]) );
    }
    if ( pC->fLearned ) 
        Msat_SolverClaBumpActivity( p, pC );
}

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Msat_ClauseCreate()

int Msat_ClauseCreate	(	Msat_Solver_t *	p,
		Msat_IntVec_t *	vLits,
		int	fLearned,
		Msat_Clause_t **	pClause_out )

FUNCTION DEFINITIONS ///.

Function*************************************************************

Synopsis [Creates a new clause.]

Description [Returns FALSE if top-level conflict detected (must be handled); TRUE otherwise. 'pClause_out' may be set to NULL if clause is already satisfied by the top-level assignment.]

SideEffects []

SeeAlso []

Definition at line 58 of file msatClause.c.

{
    int * pAssigns = Msat_SolverReadAssignsArray(p);
    Msat_ClauseVec_t ** pvWatched;
    Msat_Clause_t * pC;
    int * pLits;
    int nLits, i, j;
    int nBytes;
    Msat_Var_t Var;
    int  Sign;
 
    *pClause_out = NULL;
 
    nLits = Msat_IntVecReadSize(vLits);
    pLits = Msat_IntVecReadArray(vLits);
 
    if ( !fLearned ) 
    {
        int * pSeen = Msat_SolverReadSeenArray( p );
        int nSeenId;
        assert( Msat_SolverReadDecisionLevel(p) == 0 );
        // sorting literals makes the code trace-equivalent 
        // with to the original C++ solver
        Msat_IntVecSort( vLits, 0 );
        // increment the counter of seen twice
        nSeenId = Msat_SolverIncrementSeenId( p );
        nSeenId = Msat_SolverIncrementSeenId( p );
        // nSeenId - 1 stands for negative
        // nSeenId     stands for positive
        // Remove false literals
 
        // there is a bug here!!!!
        // when the same var in opposite polarities is given, it drops one polarity!!!
 
        for ( i = j = 0; i < nLits; i++ ) {
            // get the corresponding variable
            Var  = MSAT_LIT2VAR(pLits[i]);
            Sign = MSAT_LITSIGN(pLits[i]); // Sign=0 for positive
            // check if we already saw this variable in the this clause
            if ( pSeen[Var] >= nSeenId - 1 )
            {
                if ( (pSeen[Var] != nSeenId) == Sign ) // the same lit
                    continue;
                return 1; // two opposite polarity lits -- don't add the clause
            }
            // mark the variable as seen
            pSeen[Var] = nSeenId - !Sign;
 
            // analize the value of this literal
            if ( pAssigns[Var] != MSAT_VAR_UNASSIGNED )
            {
                if ( pAssigns[Var] == pLits[i] )
                    return 1;  // the clause is always true -- don't add anything
                // the literal has no impact - skip it
                continue;
            }
            // otherwise, add this literal to the clause
            pLits[j++] = pLits[i];
        }
        Msat_IntVecShrink( vLits, j );
        nLits = j;
/*
        // the problem with this code is that performance is very
        // sensitive to the ordering of adjacency lits
        // the best ordering requires fanins first, next fanouts
        // this ordering is more convenient to make from FRAIG
 
        // create the adjacency information
        if ( nLits > 2 )
        {
            Msat_Var_t VarI, VarJ;
            Msat_IntVec_t * pAdjI, * pAdjJ;
 
            for ( i = 0; i < nLits; i++ )
            {
                VarI = MSAT_LIT2VAR(pLits[i]);
                pAdjI = (Msat_IntVec_t *)p->vAdjacents->pArray[VarI];
 
                for ( j = i+1; j < nLits; j++ )
                {
                    VarJ = MSAT_LIT2VAR(pLits[j]);
                    pAdjJ = (Msat_IntVec_t *)p->vAdjacents->pArray[VarJ];
 
                    Msat_IntVecPushUniqueOrder( pAdjI, VarJ, 1 );
                    Msat_IntVecPushUniqueOrder( pAdjJ, VarI, 1 );
                }
            }
        }
*/
    }
    // 'vLits' is now the (possibly) reduced vector of literals.
    if ( nLits == 0 )
        return 0;
    if ( nLits == 1 )
        return Msat_SolverEnqueue( p, pLits[0], NULL );
 
    // Allocate clause:
//    nBytes = sizeof(unsigned)*(nLits + 1 + (int)fLearned);
    nBytes = sizeof(unsigned)*(nLits + 2 + (int)fLearned);
#ifdef USE_SYSTEM_MEMORY_MANAGEMENT
    pC = (Msat_Clause_t *)ABC_ALLOC( char, nBytes );
#else
    pC = (Msat_Clause_t *)Msat_MmStepEntryFetch( Msat_SolverReadMem(p), nBytes );
#endif
    pC->Num        = p->nClauses++;
    pC->fTypeA     = 0;
    pC->fMark      = 0;
    pC->fLearned   = fLearned;
    pC->nSize      = nLits;
    pC->nSizeAlloc = nBytes;
    memcpy( pC->pData, pLits, sizeof(int)*nLits );
 
    // For learnt clauses only:
    if ( fLearned )
    {
        int * pLevel = Msat_SolverReadDecisionLevelArray( p );
        int iLevelMax, iLevelCur, iLitMax;
 
        // Put the second watch on the literal with highest decision level:
        iLitMax = 1;
        iLevelMax = pLevel[ MSAT_LIT2VAR(pLits[1]) ];
        for ( i = 2; i < nLits; i++ )
        {
            iLevelCur = pLevel[ MSAT_LIT2VAR(pLits[i]) ];
            assert( iLevelCur != -1 );
            if ( iLevelMax < iLevelCur )
            // this is very strange - shouldn't it be???
            // if ( iLevelMax > iLevelCur )
                iLevelMax = iLevelCur, iLitMax = i;
        }
        pC->pData[1]       = pLits[iLitMax];
        pC->pData[iLitMax] = pLits[1];
 
        // Bumping:
        // (newly learnt clauses should be considered active)
        Msat_ClauseWriteActivity( pC, 0.0 );
        Msat_SolverClaBumpActivity( p, pC ); 
//        if ( nLits < 20 )
        for ( i = 0; i < nLits; i++ )
        {
            Msat_SolverVarBumpActivity( p, pLits[i] );
//            Msat_SolverVarBumpActivity( p, pLits[i] );
//            p->pFreq[ MSAT_LIT2VAR(pLits[i]) ]++;
        }
    }
 
    // Store clause:
    pvWatched = Msat_SolverReadWatchedArray( p );
    Msat_ClauseVecPush( pvWatched[ MSAT_LITNOT(pC->pData[0]) ], pC );
    Msat_ClauseVecPush( pvWatched[ MSAT_LITNOT(pC->pData[1]) ], pC );
    *pClause_out = pC;
    return 1;
}

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Msat_ClauseFree()

void Msat_ClauseFree	(	Msat_Solver_t *	p,
		Msat_Clause_t *	pC,
		int	fRemoveWatched )

Function*************************************************************

Synopsis [Deallocates the clause.]

Description []

SideEffects []

SeeAlso []

Definition at line 223 of file msatClause.c.

{
    if ( fRemoveWatched )
    {
        Msat_Lit_t Lit;
        Msat_ClauseVec_t ** pvWatched;
        pvWatched = Msat_SolverReadWatchedArray( p );
        Lit = MSAT_LITNOT( pC->pData[0] );
        Msat_ClauseRemoveWatch( pvWatched[Lit], pC );
        Lit = MSAT_LITNOT( pC->pData[1] );
        Msat_ClauseRemoveWatch( pvWatched[Lit], pC ); 
    }
 
#ifdef USE_SYSTEM_MEMORY_MANAGEMENT
    ABC_FREE( pC );
#else
    Msat_MmStepEntryRecycle( Msat_SolverReadMem(p), (char *)pC, pC->nSizeAlloc );
#endif
 
}

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Msat_ClauseIsLocked()

int Msat_ClauseIsLocked	(	Msat_Solver_t *	p,
		Msat_Clause_t *	pC )

Function*************************************************************

Synopsis [Checks whether the learned clause is locked.]

Description [The clause may be locked if it is the reason of a recent conflict. Such clause cannot be removed from the database.]

SideEffects []

SeeAlso []

Definition at line 278 of file msatClause.c.

{
    Msat_Clause_t ** pReasons = Msat_SolverReadReasonArray( p );
    return (int )(pReasons[MSAT_LIT2VAR(pC->pData[0])] == pC);
}

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Msat_ClausePrint()

void Msat_ClausePrint

(

Msat_Clause_t *

pC

)

Function*************************************************************

Synopsis [Prints the given clause.]

Description []

SideEffects []

SeeAlso []

Definition at line 468 of file msatClause.c.

{
    int i;
    if ( pC == NULL )
        printf( "NULL pointer" );
    else 
    {
        if ( pC->fLearned )
            printf( "Act = %.4f  ", Msat_ClauseReadActivity(pC) );
        for ( i = 0; i < (int)pC->nSize; i++ )
            printf( " %s%d", ((pC->pData[i]&1)? "-": ""),  pC->pData[i]/2 + 1 );
    }
    printf( "\n" );
}

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Msat_ClausePrintSymbols()

void Msat_ClausePrintSymbols

(

Msat_Clause_t *

pC

)

Function*************************************************************

Synopsis [Prints the given clause.]

Description []

SideEffects []

SeeAlso []

Definition at line 515 of file msatClause.c.

{
    int i;
    if ( pC == NULL )
        printf( "NULL pointer" );
    else 
    {
//        if ( pC->fLearned )
//            printf( "Act = %.4f  ", Msat_ClauseReadActivity(pC) );
        for ( i = 0; i < (int)pC->nSize; i++ )
            printf(" " L_LIT, L_lit(pC->pData[i]));
    }
    printf( "\n" );
}

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Msat_ClausePropagate()

int Msat_ClausePropagate	(	Msat_Clause_t *	pC,
		Msat_Lit_t	Lit,
		int *	pAssigns,
		Msat_Lit_t *	pLit_out )

Function*************************************************************

Synopsis [Propages the assignment.]

Description [The literal that has become true (Lit) is given to this procedure. The array of current variable assignments is given for efficiency. The output literal (pLit_out) can be the second watched literal (if TRUE is returned) or the conflict literal (if FALSE is returned). This messy interface is used to improve performance. This procedure accounts for ~50% of the runtime of the solver.]

SideEffects []

SeeAlso []

Definition at line 335 of file msatClause.c.

{
    // make sure the false literal is pC->pData[1]
    Msat_Lit_t LitF = MSAT_LITNOT(Lit);
    if ( pC->pData[0] == LitF )
         pC->pData[0] = pC->pData[1], pC->pData[1] = LitF;
    assert( pC->pData[1] == LitF );
    // if the 0-th watch is true, clause is already satisfied
    if ( pAssigns[MSAT_LIT2VAR(pC->pData[0])] == pC->pData[0] )
        return 1; 
    // look for a new watch
    if ( pC->nSize > 2 )
    {
        int i;
        for ( i = 2; i < (int)pC->nSize; i++ )
            if ( pAssigns[MSAT_LIT2VAR(pC->pData[i])] != MSAT_LITNOT(pC->pData[i]) )
            {
                pC->pData[1] = pC->pData[i], pC->pData[i] = LitF;
                *pLit_out = MSAT_LITNOT(pC->pData[1]);
                return 1; 
            }
    }
    // clause is unit under assignment
    *pLit_out = pC->pData[0];
    return 0;
}

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Msat_ClauseReadActivity()

float Msat_ClauseReadActivity

(

Msat_Clause_t *

pC

)

Function*************************************************************

Synopsis [Reads the activity of the given clause.]

Description []

SideEffects []

SeeAlso []

Definition at line 295 of file msatClause.c.

{
    float f;
 
    memcpy( &f, pC->pData + pC->nSize, sizeof (f));
    return f;
}

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Msat_ClauseReadLearned()

int Msat_ClauseReadLearned

(

Msat_Clause_t *

pC

)

Function*************************************************************

Synopsis [Access the data field of the clause.]

Description []

SideEffects []

SeeAlso []

Definition at line 255 of file msatClause.c.

{  return pC->fLearned; }

Msat_ClauseReadLits()

int * Msat_ClauseReadLits

(

Msat_Clause_t *

pC

)

Definition at line 257 of file msatClause.c.

{  return pC->pData;    }

Msat_ClauseReadMark()

int Msat_ClauseReadMark

(

Msat_Clause_t *

pC

)

Definition at line 258 of file msatClause.c.

{  return pC->fMark;    }

Msat_ClauseReadNum()

int Msat_ClauseReadNum

(

Msat_Clause_t *

pC

)

Definition at line 259 of file msatClause.c.

{  return pC->Num;      }

Msat_ClauseReadSize()

int Msat_ClauseReadSize

(

Msat_Clause_t *

pC

)

Definition at line 256 of file msatClause.c.

{  return pC->nSize;    }

Msat_ClauseReadTypeA()

int Msat_ClauseReadTypeA

(

Msat_Clause_t *

pC

)

Definition at line 260 of file msatClause.c.

{  return pC->fTypeA;    }

Msat_ClauseRemoveWatch()

void Msat_ClauseRemoveWatch	(	Msat_ClauseVec_t *	vClauses,
		Msat_Clause_t *	pC )

Function*************************************************************

Synopsis [Removes the given clause from the watched list.]

Description []

SideEffects []

SeeAlso []

Definition at line 444 of file msatClause.c.

{
    Msat_Clause_t ** pClauses;
    int nClauses, i;
    nClauses = Msat_ClauseVecReadSize( vClauses );
    pClauses = Msat_ClauseVecReadArray( vClauses );
    for ( i = 0; pClauses[i] != pC; i++ )
        assert( i < nClauses );
    for (      ; i < nClauses - 1; i++ )
        pClauses[i] = pClauses[i+1];
    Msat_ClauseVecPop( vClauses );
}

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Msat_ClauseSetMark()

void Msat_ClauseSetMark	(	Msat_Clause_t *	pC,
		int	fMark )

Definition at line 262 of file msatClause.c.

{  pC->fMark = fMark;   }

Msat_ClauseSetNum()

void Msat_ClauseSetNum	(	Msat_Clause_t *	pC,
		int	Num )

Definition at line 263 of file msatClause.c.

{  pC->Num = Num;       }

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Msat_ClauseSetTypeA()

void Msat_ClauseSetTypeA	(	Msat_Clause_t *	pC,
		int	fTypeA )

Definition at line 264 of file msatClause.c.

{  pC->fTypeA = fTypeA; }

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Msat_ClauseSimplify()

int Msat_ClauseSimplify	(	Msat_Clause_t *	pC,
		int *	pAssigns )

Function*************************************************************

Synopsis [Simplifies the clause.]

Description [Assumes everything has been propagated! (esp. watches in clauses are NOT unsatisfied)]

SideEffects []

SeeAlso []

Definition at line 374 of file msatClause.c.

{
    Msat_Var_t Var;
    int i, j;
    for ( i = j = 0; i < (int)pC->nSize; i++ )
    {
        Var = MSAT_LIT2VAR(pC->pData[i]);
        if ( pAssigns[Var] == MSAT_VAR_UNASSIGNED )
        {
            pC->pData[j++] = pC->pData[i];
            continue;
        }
        if ( pAssigns[Var] == pC->pData[i] )
            return 1;
        // otherwise, the value of the literal is false
        // make sure, this literal is not watched
        assert( i >= 2 );
    }
    // if the size has changed, update it and move activity
    if ( j < (int)pC->nSize )
    {
        float Activ = Msat_ClauseReadActivity(pC);
        pC->nSize = j;
        Msat_ClauseWriteActivity(pC, Activ);
    }
    return 0;
}

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Msat_ClauseWriteActivity()

void Msat_ClauseWriteActivity	(	Msat_Clause_t *	pC,
		float	Num )

Function*************************************************************

Synopsis [Sets the activity of the clause.]

Description []

SideEffects []

SeeAlso []

Definition at line 314 of file msatClause.c.

{
    memcpy( pC->pData + pC->nSize, &Num, sizeof (Num) );
}

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Msat_ClauseWriteDimacs()

void Msat_ClauseWriteDimacs	(	FILE *	pFile,
		Msat_Clause_t *	pC,
		int	fIncrement )

Function*************************************************************

Synopsis [Writes the given clause in a file in DIMACS format.]

Description []

SideEffects []

SeeAlso []

Definition at line 494 of file msatClause.c.

{
    int i;
    for ( i = 0; i < (int)pC->nSize; i++ )
        fprintf( pFile, "%s%d ", ((pC->pData[i]&1)? "-": ""),  pC->pData[i]/2 + (int)(fIncrement>0) );
    if ( fIncrement )
        fprintf( pFile, "0" );
    fprintf( pFile, "\n" );
}

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