/**CFile**************************************************************** FileName [satInter.c] SystemName [ABC: Logic synthesis and verification system.] PackageName [SAT sat_solver.] Synopsis [Interpolation package.] Author [Alan Mishchenko] Affiliation [UC Berkeley] Date [Ver. 1.0. Started - June 20, 2005.] Revision [$Id: satInter.c,v 1.4 2005/09/16 22:55:03 casem Exp $] ***********************************************************************/ #include #include #include #include #include "satStore.h" #include "misc/vec/vec.h" ABC_NAMESPACE_IMPL_START //////////////////////////////////////////////////////////////////////// /// DECLARATIONS /// //////////////////////////////////////////////////////////////////////// // variable assignments static const lit LIT_UNDEF = 0xffffffff; // interpolation manager struct Intp_Man_t_ { // clauses of the problems Sto_Man_t * pCnf; // the set of CNF clauses for A and B // various parameters int fVerbose; // verbosiness flag int fProofVerif; // verifies the proof int fProofWrite; // writes the proof file int nVarsAlloc; // the allocated size of var arrays int nClosAlloc; // the allocated size of clause arrays // internal BCP int nRootSize; // the number of root level assignments int nTrailSize; // the number of assignments made lit * pTrail; // chronological order of assignments (size nVars) lit * pAssigns; // assignments by variable (size nVars) char * pSeens; // temporary mark (size nVars) Sto_Cls_t ** pReasons; // reasons for each assignment (size nVars) Sto_Cls_t ** pWatches; // watched clauses for each literal (size 2*nVars) // proof data // Vec_Int_t * vAnties; // anticedents for all clauses // Vec_Int_t * vBreaks; // beginnings of anticedents for each clause Vec_Ptr_t * vAntClas; // anticedant clauses int nAntStart; // starting antecedant clause // proof recording int Counter; // counter of resolved clauses int * pProofNums; // the proof numbers for each clause (size nClauses) FILE * pFile; // the file for proof recording // internal verification lit * pResLits; // the literals of the resolvent int nResLits; // the number of literals of the resolvent int nResLitsAlloc;// the number of literals of the resolvent // runtime stats abctime timeBcp; // the runtime for BCP abctime timeTrace; // the runtime of trace construction abctime timeTotal; // the total runtime of interpolation }; // reading/writing the proof for a clause static inline int Intp_ManProofGet( Intp_Man_t * p, Sto_Cls_t * pCls ) { return p->pProofNums[pCls->Id]; } static inline void Intp_ManProofSet( Intp_Man_t * p, Sto_Cls_t * pCls, int n ) { p->pProofNums[pCls->Id] = n; } //////////////////////////////////////////////////////////////////////// /// FUNCTION DEFINITIONS /// //////////////////////////////////////////////////////////////////////// /**Function************************************************************* Synopsis [Allocate proof manager.] Description [] SideEffects [] SeeAlso [] ***********************************************************************/ Intp_Man_t * Intp_ManAlloc() { Intp_Man_t * p; // allocate the manager p = (Intp_Man_t *)ABC_ALLOC( char, sizeof(Intp_Man_t) ); memset( p, 0, sizeof(Intp_Man_t) ); // verification p->nResLitsAlloc = (1<<16); p->pResLits = ABC_ALLOC( lit, p->nResLitsAlloc ); // proof recording // p->vAnties = Vec_IntAlloc( 1000 ); // p->vBreaks = Vec_IntAlloc( 1000 ); p->vAntClas = Vec_PtrAlloc( 1000 ); p->nAntStart = 0; // parameters p->fProofWrite = 0; p->fProofVerif = 1; return p; } /**Function************************************************************* Synopsis [Resize proof manager.] Description [] SideEffects [] SeeAlso [] ***********************************************************************/ void Intp_ManResize( Intp_Man_t * p ) { // check if resizing is needed if ( p->nVarsAlloc < p->pCnf->nVars ) { // find the new size if ( p->nVarsAlloc == 0 ) p->nVarsAlloc = 1; while ( p->nVarsAlloc < p->pCnf->nVars ) p->nVarsAlloc *= 2; // resize the arrays p->pTrail = ABC_REALLOC(lit, p->pTrail, p->nVarsAlloc ); p->pAssigns = ABC_REALLOC(lit, p->pAssigns, p->nVarsAlloc ); p->pSeens = ABC_REALLOC(char, p->pSeens, p->nVarsAlloc ); // p->pVarTypes = ABC_REALLOC(int, p->pVarTypes, p->nVarsAlloc ); p->pReasons = ABC_REALLOC(Sto_Cls_t *, p->pReasons, p->nVarsAlloc ); p->pWatches = ABC_REALLOC(Sto_Cls_t *, p->pWatches, p->nVarsAlloc*2 ); } // clean the free space memset( p->pAssigns , 0xff, sizeof(lit) * p->pCnf->nVars ); memset( p->pSeens , 0, sizeof(char) * p->pCnf->nVars ); // memset( p->pVarTypes, 0, sizeof(int) * p->pCnf->nVars ); memset( p->pReasons , 0, sizeof(Sto_Cls_t *) * p->pCnf->nVars ); memset( p->pWatches , 0, sizeof(Sto_Cls_t *) * p->pCnf->nVars*2 ); // check if resizing of clauses is needed if ( p->nClosAlloc < p->pCnf->nClauses ) { // find the new size if ( p->nClosAlloc == 0 ) p->nClosAlloc = 1; while ( p->nClosAlloc < p->pCnf->nClauses ) p->nClosAlloc *= 2; // resize the arrays p->pProofNums = ABC_REALLOC( int, p->pProofNums, p->nClosAlloc ); } memset( p->pProofNums, 0, sizeof(int) * p->pCnf->nClauses ); } /**Function************************************************************* Synopsis [Deallocate proof manager.] Description [] SideEffects [] SeeAlso [] ***********************************************************************/ void Intp_ManFree( Intp_Man_t * p ) { /* printf( "Runtime stats:\n" ); ABC_PRT( "BCP ", p->timeBcp ); ABC_PRT( "Trace ", p->timeTrace ); ABC_PRT( "TOTAL ", p->timeTotal ); */ // Vec_IntFree( p->vAnties ); // Vec_IntFree( p->vBreaks ); Vec_VecFree( (Vec_Vec_t *)p->vAntClas ); // ABC_FREE( p->pInters ); ABC_FREE( p->pProofNums ); ABC_FREE( p->pTrail ); ABC_FREE( p->pAssigns ); ABC_FREE( p->pSeens ); // ABC_FREE( p->pVarTypes ); ABC_FREE( p->pReasons ); ABC_FREE( p->pWatches ); ABC_FREE( p->pResLits ); ABC_FREE( p ); } /**Function************************************************************* Synopsis [Prints the clause.] Description [] SideEffects [] SeeAlso [] ***********************************************************************/ void Intp_ManPrintClause( Intp_Man_t * p, Sto_Cls_t * pClause ) { int i; printf( "Clause ID = %d. Proof = %d. {", pClause->Id, Intp_ManProofGet(p, pClause) ); for ( i = 0; i < (int)pClause->nLits; i++ ) printf( " %d", pClause->pLits[i] ); printf( " }\n" ); } /**Function************************************************************* Synopsis [Prints the resolvent.] Description [] SideEffects [] SeeAlso [] ***********************************************************************/ void Intp_ManPrintResolvent( lit * pResLits, int nResLits ) { int i; printf( "Resolvent: {" ); for ( i = 0; i < nResLits; i++ ) printf( " %d", pResLits[i] ); printf( " }\n" ); } /**Function************************************************************* Synopsis [Prints the interpolant for one clause.] Description [] SideEffects [] SeeAlso [] ***********************************************************************/ void Intp_ManPrintInterOne( Intp_Man_t * p, Sto_Cls_t * pClause ) { printf( "Clause %2d : ", pClause->Id ); // Extra_PrintBinary___( stdout, Intp_ManAigRead(p, pClause), (1 << p->nVarsAB) ); printf( "\n" ); } /**Function************************************************************* Synopsis [Adds one clause to the watcher list.] Description [] SideEffects [] SeeAlso [] ***********************************************************************/ static inline void Intp_ManWatchClause( Intp_Man_t * p, Sto_Cls_t * pClause, lit Lit ) { assert( lit_check(Lit, p->pCnf->nVars) ); if ( pClause->pLits[0] == Lit ) pClause->pNext0 = p->pWatches[lit_neg(Lit)]; else { assert( pClause->pLits[1] == Lit ); pClause->pNext1 = p->pWatches[lit_neg(Lit)]; } p->pWatches[lit_neg(Lit)] = pClause; } /**Function************************************************************* Synopsis [Records implication.] Description [] SideEffects [] SeeAlso [] ***********************************************************************/ static inline int Intp_ManEnqueue( Intp_Man_t * p, lit Lit, Sto_Cls_t * pReason ) { int Var = lit_var(Lit); if ( p->pAssigns[Var] != LIT_UNDEF ) return p->pAssigns[Var] == Lit; p->pAssigns[Var] = Lit; p->pReasons[Var] = pReason; p->pTrail[p->nTrailSize++] = Lit; //printf( "assigning var %d value %d\n", Var, !lit_sign(Lit) ); return 1; } /**Function************************************************************* Synopsis [Records implication.] Description [] SideEffects [] SeeAlso [] ***********************************************************************/ static inline void Intp_ManCancelUntil( Intp_Man_t * p, int Level ) { lit Lit; int i, Var; for ( i = p->nTrailSize - 1; i >= Level; i-- ) { Lit = p->pTrail[i]; Var = lit_var( Lit ); p->pReasons[Var] = NULL; p->pAssigns[Var] = LIT_UNDEF; //printf( "cancelling var %d\n", Var ); } p->nTrailSize = Level; } /**Function************************************************************* Synopsis [Propagate one assignment.] Description [] SideEffects [] SeeAlso [] ***********************************************************************/ static inline Sto_Cls_t * Intp_ManPropagateOne( Intp_Man_t * p, lit Lit ) { Sto_Cls_t ** ppPrev, * pCur, * pTemp; lit LitF = lit_neg(Lit); int i; // iterate through the literals ppPrev = p->pWatches + Lit; for ( pCur = p->pWatches[Lit]; pCur; pCur = *ppPrev ) { // make sure the false literal is in the second literal of the clause if ( pCur->pLits[0] == LitF ) { pCur->pLits[0] = pCur->pLits[1]; pCur->pLits[1] = LitF; pTemp = pCur->pNext0; pCur->pNext0 = pCur->pNext1; pCur->pNext1 = pTemp; } assert( pCur->pLits[1] == LitF ); // if the first literal is true, the clause is satisfied if ( pCur->pLits[0] == p->pAssigns[lit_var(pCur->pLits[0])] ) { ppPrev = &pCur->pNext1; continue; } // look for a new literal to watch for ( i = 2; i < (int)pCur->nLits; i++ ) { // skip the case when the literal is false if ( lit_neg(pCur->pLits[i]) == p->pAssigns[lit_var(pCur->pLits[i])] ) continue; // the literal is either true or unassigned - watch it pCur->pLits[1] = pCur->pLits[i]; pCur->pLits[i] = LitF; // remove this clause from the watch list of Lit *ppPrev = pCur->pNext1; // add this clause to the watch list of pCur->pLits[i] (now it is pCur->pLits[1]) Intp_ManWatchClause( p, pCur, pCur->pLits[1] ); break; } if ( i < (int)pCur->nLits ) // found new watch continue; // clause is unit - enqueue new implication if ( Intp_ManEnqueue(p, pCur->pLits[0], pCur) ) { ppPrev = &pCur->pNext1; continue; } // conflict detected - return the conflict clause return pCur; } return NULL; } /**Function************************************************************* Synopsis [Propagate the current assignments.] Description [] SideEffects [] SeeAlso [] ***********************************************************************/ Sto_Cls_t * Intp_ManPropagate( Intp_Man_t * p, int Start ) { Sto_Cls_t * pClause; int i; abctime clk = Abc_Clock(); for ( i = Start; i < p->nTrailSize; i++ ) { pClause = Intp_ManPropagateOne( p, p->pTrail[i] ); if ( pClause ) { p->timeBcp += Abc_Clock() - clk; return pClause; } } p->timeBcp += Abc_Clock() - clk; return NULL; } /**Function************************************************************* Synopsis [Writes one root clause into a file.] Description [] SideEffects [] SeeAlso [] ***********************************************************************/ void Intp_ManProofWriteOne( Intp_Man_t * p, Sto_Cls_t * pClause ) { Intp_ManProofSet( p, pClause, ++p->Counter ); if ( p->fProofWrite ) { int v; fprintf( p->pFile, "%d", Intp_ManProofGet(p, pClause) ); for ( v = 0; v < (int)pClause->nLits; v++ ) fprintf( p->pFile, " %d", lit_print(pClause->pLits[v]) ); fprintf( p->pFile, " 0 0\n" ); } } /**Function************************************************************* Synopsis [Traces the proof for one clause.] Description [] SideEffects [] SeeAlso [] ***********************************************************************/ int Intp_ManProofTraceOne( Intp_Man_t * p, Sto_Cls_t * pConflict, Sto_Cls_t * pFinal ) { Sto_Cls_t * pReason; int i, v, Var, PrevId; int fPrint = 0; abctime clk = Abc_Clock(); // collect resolvent literals if ( p->fProofVerif ) { assert( (int)pConflict->nLits <= p->nResLitsAlloc ); memcpy( p->pResLits, pConflict->pLits, sizeof(lit) * pConflict->nLits ); p->nResLits = pConflict->nLits; } // mark all the variables in the conflict as seen for ( v = 0; v < (int)pConflict->nLits; v++ ) p->pSeens[lit_var(pConflict->pLits[v])] = 1; // start the anticedents // pFinal->pAntis = Vec_PtrAlloc( 32 ); // Vec_PtrPush( pFinal->pAntis, pConflict ); // assert( pFinal->Id == Vec_IntSize(p->vBreaks) ); // Vec_IntPush( p->vBreaks, Vec_IntSize(p->vAnties) ); // Vec_IntPush( p->vAnties, pConflict->Id ); { Vec_Int_t * vAnts = Vec_IntAlloc( 16 ); assert( Vec_PtrSize(p->vAntClas) == pFinal->Id - p->nAntStart ); Vec_IntPush( vAnts, pConflict->Id ); Vec_PtrPush( p->vAntClas, vAnts ); } // if ( p->pCnf->nClausesA ) // Intp_ManAigCopy( p, Intp_ManAigRead(p, pFinal), Intp_ManAigRead(p, pConflict) ); // follow the trail backwards PrevId = Intp_ManProofGet(p, pConflict); for ( i = p->nTrailSize - 1; i >= 0; i-- ) { // skip literals that are not involved Var = lit_var(p->pTrail[i]); if ( !p->pSeens[Var] ) continue; p->pSeens[Var] = 0; // skip literals of the resulting clause pReason = p->pReasons[Var]; if ( pReason == NULL ) continue; assert( p->pTrail[i] == pReason->pLits[0] ); // add the variables to seen for ( v = 1; v < (int)pReason->nLits; v++ ) p->pSeens[lit_var(pReason->pLits[v])] = 1; // record the reason clause assert( Intp_ManProofGet(p, pReason) > 0 ); p->Counter++; if ( p->fProofWrite ) fprintf( p->pFile, "%d * %d %d 0\n", p->Counter, PrevId, Intp_ManProofGet(p, pReason) ); PrevId = p->Counter; // if ( p->pCnf->nClausesA ) // { // if ( p->pVarTypes[Var] == 1 ) // var of A // Intp_ManAigOr( p, Intp_ManAigRead(p, pFinal), Intp_ManAigRead(p, pReason) ); // else // Intp_ManAigAnd( p, Intp_ManAigRead(p, pFinal), Intp_ManAigRead(p, pReason) ); // } // resolve the temporary resolvent with the reason clause if ( p->fProofVerif ) { int v1, v2; if ( fPrint ) Intp_ManPrintResolvent( p->pResLits, p->nResLits ); // check that the var is present in the resolvent for ( v1 = 0; v1 < p->nResLits; v1++ ) if ( lit_var(p->pResLits[v1]) == Var ) break; if ( v1 == p->nResLits ) printf( "Recording clause %d: Cannot find variable %d in the temporary resolvent.\n", pFinal->Id, Var ); if ( p->pResLits[v1] != lit_neg(pReason->pLits[0]) ) printf( "Recording clause %d: The resolved variable %d is in the wrong polarity.\n", pFinal->Id, Var ); // remove this variable from the resolvent assert( lit_var(p->pResLits[v1]) == Var ); p->nResLits--; for ( ; v1 < p->nResLits; v1++ ) p->pResLits[v1] = p->pResLits[v1+1]; // add variables of the reason clause for ( v2 = 1; v2 < (int)pReason->nLits; v2++ ) { for ( v1 = 0; v1 < p->nResLits; v1++ ) if ( lit_var(p->pResLits[v1]) == lit_var(pReason->pLits[v2]) ) break; // if it is a new variable, add it to the resolvent if ( v1 == p->nResLits ) { if ( p->nResLits == p->nResLitsAlloc ) printf( "Recording clause %d: Ran out of space for intermediate resolvent.\n", pFinal->Id ); p->pResLits[ p->nResLits++ ] = pReason->pLits[v2]; continue; } // if the variable is the same, the literal should be the same too if ( p->pResLits[v1] == pReason->pLits[v2] ) continue; // the literal is different printf( "Recording clause %d: Trying to resolve the clause with more than one opposite literal.\n", pFinal->Id ); } } // Vec_PtrPush( pFinal->pAntis, pReason ); // Vec_IntPush( p->vAnties, pReason->Id ); Vec_IntPush( (Vec_Int_t *)Vec_PtrEntryLast(p->vAntClas), pReason->Id ); } // unmark all seen variables // for ( i = p->nTrailSize - 1; i >= 0; i-- ) // p->pSeens[lit_var(p->pTrail[i])] = 0; // check that the literals are unmarked // for ( i = p->nTrailSize - 1; i >= 0; i-- ) // assert( p->pSeens[lit_var(p->pTrail[i])] == 0 ); // use the resulting clause to check the correctness of resolution if ( p->fProofVerif ) { int v1, v2; if ( fPrint ) Intp_ManPrintResolvent( p->pResLits, p->nResLits ); for ( v1 = 0; v1 < p->nResLits; v1++ ) { for ( v2 = 0; v2 < (int)pFinal->nLits; v2++ ) if ( pFinal->pLits[v2] == p->pResLits[v1] ) break; if ( v2 < (int)pFinal->nLits ) continue; break; } if ( v1 < p->nResLits ) { printf( "Recording clause %d: The final resolvent is wrong.\n", pFinal->Id ); Intp_ManPrintClause( p, pConflict ); Intp_ManPrintResolvent( p->pResLits, p->nResLits ); Intp_ManPrintClause( p, pFinal ); } // if there are literals in the clause that are not in the resolvent // it means that the derived resolvent is stronger than the clause // we can replace the clause with the resolvent by removing these literals if ( p->nResLits != (int)pFinal->nLits ) { for ( v1 = 0; v1 < (int)pFinal->nLits; v1++ ) { for ( v2 = 0; v2 < p->nResLits; v2++ ) if ( pFinal->pLits[v1] == p->pResLits[v2] ) break; if ( v2 < p->nResLits ) continue; // remove literal v1 from the final clause pFinal->nLits--; for ( v2 = v1; v2 < (int)pFinal->nLits; v2++ ) pFinal->pLits[v2] = pFinal->pLits[v2+1]; v1--; } assert( p->nResLits == (int)pFinal->nLits ); } } p->timeTrace += Abc_Clock() - clk; // return the proof pointer // if ( p->pCnf->nClausesA ) // { // Intp_ManPrintInterOne( p, pFinal ); // } Intp_ManProofSet( p, pFinal, p->Counter ); // make sure the same proof ID is not asssigned to two consecutive clauses assert( p->pProofNums[pFinal->Id-1] != p->Counter ); // if ( p->pProofNums[pFinal->Id] == p->pProofNums[pFinal->Id-1] ) // p->pProofNums[pFinal->Id] = p->pProofNums[pConflict->Id]; return p->Counter; } /**Function************************************************************* Synopsis [Records the proof for one clause.] Description [] SideEffects [] SeeAlso [] ***********************************************************************/ int Intp_ManProofRecordOne( Intp_Man_t * p, Sto_Cls_t * pClause ) { Sto_Cls_t * pConflict; int i; // empty clause never ends up there assert( pClause->nLits > 0 ); if ( pClause->nLits == 0 ) printf( "Error: Empty clause is attempted.\n" ); assert( !pClause->fRoot ); assert( p->nTrailSize == p->nRootSize ); // if any of the clause literals are already assumed // it means that the clause is redundant and can be skipped for ( i = 0; i < (int)pClause->nLits; i++ ) if ( p->pAssigns[lit_var(pClause->pLits[i])] == pClause->pLits[i] ) { // Vec_IntPush( p->vBreaks, Vec_IntSize(p->vAnties) ); Vec_PtrPush( p->vAntClas, Vec_IntAlloc(0) ); return 1; } // add assumptions to the trail for ( i = 0; i < (int)pClause->nLits; i++ ) if ( !Intp_ManEnqueue( p, lit_neg(pClause->pLits[i]), NULL ) ) { assert( 0 ); // impossible return 0; } // propagate the assumptions pConflict = Intp_ManPropagate( p, p->nRootSize ); if ( pConflict == NULL ) { assert( 0 ); // cannot prove return 0; } // skip the clause if it is weaker or the same as the conflict clause if ( pClause->nLits >= pConflict->nLits ) { // check if every literal of conflict clause can be found in the given clause int j; for ( i = 0; i < (int)pConflict->nLits; i++ ) { for ( j = 0; j < (int)pClause->nLits; j++ ) if ( pConflict->pLits[i] == pClause->pLits[j] ) break; if ( j == (int)pClause->nLits ) // literal pConflict->pLits[i] is not found break; } if ( i == (int)pConflict->nLits ) // all lits are found { // undo to the root level Intp_ManCancelUntil( p, p->nRootSize ); // Vec_IntPush( p->vBreaks, Vec_IntSize(p->vAnties) ); Vec_PtrPush( p->vAntClas, Vec_IntAlloc(0) ); return 1; } } // construct the proof Intp_ManProofTraceOne( p, pConflict, pClause ); // undo to the root level Intp_ManCancelUntil( p, p->nRootSize ); // add large clauses to the watched lists if ( pClause->nLits > 1 ) { Intp_ManWatchClause( p, pClause, pClause->pLits[0] ); Intp_ManWatchClause( p, pClause, pClause->pLits[1] ); return 1; } assert( pClause->nLits == 1 ); // if the clause proved is unit, add it and propagate if ( !Intp_ManEnqueue( p, pClause->pLits[0], pClause ) ) { assert( 0 ); // impossible return 0; } // propagate the assumption pConflict = Intp_ManPropagate( p, p->nRootSize ); if ( pConflict ) { // insert place-holders till the empty clause while ( Vec_PtrSize(p->vAntClas) < p->pCnf->pEmpty->Id - p->nAntStart ) Vec_PtrPush( p->vAntClas, Vec_IntAlloc(0) ); // construct the proof for the empty clause Intp_ManProofTraceOne( p, pConflict, p->pCnf->pEmpty ); // if ( p->fVerbose ) // printf( "Found last conflict after adding unit clause number %d!\n", pClause->Id ); return 0; } // update the root level p->nRootSize = p->nTrailSize; return 1; } /**Function************************************************************* Synopsis [Propagate the root clauses.] Description [] SideEffects [] SeeAlso [] ***********************************************************************/ int Intp_ManProcessRoots( Intp_Man_t * p ) { Sto_Cls_t * pClause; int Counter; // make sure the root clauses are preceeding the learnt clauses Counter = 0; Sto_ManForEachClause( p->pCnf, pClause ) { assert( (int)pClause->fA == (Counter < (int)p->pCnf->nClausesA) ); assert( (int)pClause->fRoot == (Counter < (int)p->pCnf->nRoots) ); Counter++; } assert( p->pCnf->nClauses == Counter ); // make sure the last clause if empty assert( p->pCnf->pTail->nLits == 0 ); // go through the root unit clauses p->nTrailSize = 0; Sto_ManForEachClauseRoot( p->pCnf, pClause ) { // create watcher lists for the root clauses if ( pClause->nLits > 1 ) { Intp_ManWatchClause( p, pClause, pClause->pLits[0] ); Intp_ManWatchClause( p, pClause, pClause->pLits[1] ); } // empty clause and large clauses if ( pClause->nLits != 1 ) continue; // unit clause assert( lit_check(pClause->pLits[0], p->pCnf->nVars) ); if ( !Intp_ManEnqueue( p, pClause->pLits[0], pClause ) ) { // detected root level conflict // printf( "Error in Intp_ManProcessRoots(): Detected a root-level conflict too early!\n" ); // assert( 0 ); // detected root level conflict Intp_ManProofTraceOne( p, pClause, p->pCnf->pEmpty ); if ( p->fVerbose ) printf( "Found root level conflict!\n" ); return 0; } } // propagate the root unit clauses pClause = Intp_ManPropagate( p, 0 ); if ( pClause ) { // detected root level conflict Intp_ManProofTraceOne( p, pClause, p->pCnf->pEmpty ); if ( p->fVerbose ) printf( "Found root level conflict!\n" ); return 0; } // set the root level p->nRootSize = p->nTrailSize; return 1; } /**Function************************************************************* Synopsis [Verifies the UNSAT core.] Description [Takes the interpolation manager, the CNF derived by the SAT solver, which includes the root clauses and the learned clauses. Returns the array of integers representing the number of root clauses that are in the UNSAT core.] SideEffects [] SeeAlso [] ***********************************************************************/ void Intp_ManUnsatCoreVerify( Sto_Man_t * pCnf, Vec_Int_t * vCore ) { int fVerbose = 0; int nConfMax = 1000000; sat_solver * pSat; Sto_Cls_t * pClause; Vec_Ptr_t * vClauses; int i, iClause, RetValue; abctime clk = Abc_Clock(); // collect the clauses vClauses = Vec_PtrAlloc( 1000 ); Sto_ManForEachClauseRoot( pCnf, pClause ) { assert( Vec_PtrSize(vClauses) == pClause->Id ); Vec_PtrPush( vClauses, pClause ); } // create new SAT solver pSat = sat_solver_new(); // sat_solver_setnvars( pSat, nSatVars ); Vec_IntForEachEntry( vCore, iClause, i ) { pClause = (Sto_Cls_t *)Vec_PtrEntry( vClauses, iClause ); if ( !sat_solver_addclause( pSat, pClause->pLits, pClause->pLits+pClause->nLits ) ) { printf( "The core verification problem is trivially UNSAT.\n" ); break; } } Vec_PtrFree( vClauses ); // solve the problem RetValue = sat_solver_solve( pSat, NULL, NULL, (ABC_INT64_T)nConfMax, (ABC_INT64_T)0, (ABC_INT64_T)0, (ABC_INT64_T)0 ); sat_solver_delete( pSat ); if ( fVerbose ) { if ( RetValue == l_Undef ) printf( "Conflict limit is reached. " ); else if ( RetValue == l_True ) printf( "UNSAT core verification FAILED. " ); else printf( "UNSAT core verification succeeded. " ); ABC_PRT( "Time", Abc_Clock() - clk ); } else { if ( RetValue == l_True ) printf( "UNSAT core verification FAILED. \n" ); } } /**Function************************************************************* Synopsis [Recursively computes the UNSAT core.] Description [] SideEffects [] SeeAlso [] ***********************************************************************/ void Intp_ManUnsatCore_rec( Vec_Ptr_t * vAntClas, int iThis, Vec_Int_t * vCore, int nRoots, Vec_Str_t * vVisited, int fLearned ) { // int i, iStop, iStart; Vec_Int_t * vAnt; int i, Entry; // skip visited clauses if ( Vec_StrEntry( vVisited, iThis ) ) return; Vec_StrWriteEntry( vVisited, iThis, 1 ); // add a root clause to the core if ( iThis < nRoots ) { if ( !fLearned ) Vec_IntPush( vCore, iThis ); return; } // iterate through the clauses // iStart = Vec_IntEntry( vBreaks, iThis ); // iStop = Vec_IntEntry( vBreaks, iThis+1 ); // assert( iStop != -1 ); // for ( i = iStart; i < iStop; i++ ) vAnt = (Vec_Int_t *)Vec_PtrEntry( vAntClas, iThis - nRoots ); Vec_IntForEachEntry( vAnt, Entry, i ) // Intp_ManUnsatCore_rec( vAntClas, Vec_IntEntry(vAnties, i), vCore, nRoots, vVisited ); Intp_ManUnsatCore_rec( vAntClas, Entry, vCore, nRoots, vVisited, fLearned ); // collect learned clause if ( fLearned ) Vec_IntPush( vCore, iThis ); } /**Function************************************************************* Synopsis [Computes UNSAT core of the satisfiablity problem.] Description [Takes the interpolation manager, the CNF derived by the SAT solver, which includes the root clauses and the learned clauses. Returns the array of integers representing the number of root clauses that are in the UNSAT core.] SideEffects [] SeeAlso [] ***********************************************************************/ void * Intp_ManUnsatCore( Intp_Man_t * p, Sto_Man_t * pCnf, int fLearned, int fVerbose ) { Vec_Int_t * vCore; Vec_Str_t * vVisited; Sto_Cls_t * pClause; int RetValue = 1; abctime clkTotal = Abc_Clock(); // check that the CNF makes sense assert( pCnf->nVars > 0 && pCnf->nClauses > 0 ); p->pCnf = pCnf; p->fVerbose = fVerbose; // adjust the manager Intp_ManResize( p ); // construct proof for each clause // start the proof if ( p->fProofWrite ) { p->pFile = fopen( "proof.cnf_", "w" ); p->Counter = 0; } // write the root clauses // Vec_IntClear( p->vAnties ); // Vec_IntFill( p->vBreaks, p->pCnf->nRoots, 0 ); Vec_PtrClear( p->vAntClas ); p->nAntStart = p->pCnf->nRoots; Sto_ManForEachClauseRoot( p->pCnf, pClause ) Intp_ManProofWriteOne( p, pClause ); // propagate root level assignments if ( Intp_ManProcessRoots( p ) ) { // if there is no conflict, consider learned clauses Sto_ManForEachClause( p->pCnf, pClause ) { if ( pClause->fRoot ) continue; if ( !Intp_ManProofRecordOne( p, pClause ) ) { RetValue = 0; break; } } } // add the last breaker // assert( p->pCnf->pEmpty->Id == Vec_IntSize(p->vBreaks) - 1 ); // Vec_IntPush( p->vBreaks, Vec_IntSize(p->vAnties) ); assert( p->pCnf->pEmpty->Id - p->nAntStart == Vec_PtrSize(p->vAntClas) - 1 ); Vec_PtrPush( p->vAntClas, Vec_IntAlloc(0) ); // stop the proof if ( p->fProofWrite ) { fclose( p->pFile ); // Sat_ProofChecker( "proof.cnf_" ); p->pFile = NULL; } if ( fVerbose ) { // ABC_PRT( "Core", Abc_Clock() - clkTotal ); printf( "Vars = %d. Roots = %d. Learned = %d. Resol steps = %d. Ave = %.2f. Mem = %.2f MB\n", p->pCnf->nVars, p->pCnf->nRoots, p->pCnf->nClauses-p->pCnf->nRoots, p->Counter, 1.0*(p->Counter-p->pCnf->nRoots)/(p->pCnf->nClauses-p->pCnf->nRoots), 1.0*Sto_ManMemoryReport(p->pCnf)/(1<<20) ); p->timeTotal += Abc_Clock() - clkTotal; } // derive the UNSAT core vCore = Vec_IntAlloc( 1000 ); vVisited = Vec_StrStart( p->pCnf->pEmpty->Id+1 ); Intp_ManUnsatCore_rec( p->vAntClas, p->pCnf->pEmpty->Id, vCore, p->pCnf->nRoots, vVisited, fLearned ); Vec_StrFree( vVisited ); if ( fVerbose ) printf( "Root clauses = %d. Learned clauses = %d. UNSAT core size = %d.\n", p->pCnf->nRoots, p->pCnf->nClauses-p->pCnf->nRoots, Vec_IntSize(vCore) ); // Intp_ManUnsatCoreVerify( p->pCnf, vCore ); return vCore; } /**Function************************************************************* Synopsis [Prints learned clauses in terms of original problem varibles.] Description [] SideEffects [] SeeAlso [] ***********************************************************************/ void Intp_ManUnsatCorePrintForBmc( FILE * pFile, Sto_Man_t * pCnf, void * vCore0, void * vVarMap0 ) { Vec_Int_t * vCore = (Vec_Int_t *)vCore0; Vec_Int_t * vVarMap = (Vec_Int_t *)vVarMap0; Vec_Ptr_t * vClaMap; Sto_Cls_t * pClause; int v, i, iClause, fCompl, iObj, iFrame; // create map of clause vClaMap = Vec_PtrAlloc( pCnf->nClauses ); Sto_ManForEachClause( pCnf, pClause ) Vec_PtrPush( vClaMap, pClause ); // print clauses fprintf( pFile, "UNSAT contains %d learned clauses:\n", Vec_IntSize(vCore) ); Vec_IntForEachEntry( vCore, iClause, i ) { pClause = (Sto_Cls_t *)Vec_PtrEntry(vClaMap, iClause); fprintf( pFile, "%6d : %6d : ", i, iClause - pCnf->nRoots ); for ( v = 0; v < (int)pClause->nLits; v++ ) { fCompl = Abc_LitIsCompl(pClause->pLits[v]); iObj = Vec_IntEntry(vVarMap, 2*Abc_Lit2Var(pClause->pLits[v])); iFrame = Vec_IntEntry(vVarMap, 2*Abc_Lit2Var(pClause->pLits[v])+1); fprintf( pFile, "%s%d(%d) ", fCompl ? "!":"", iObj, iFrame ); } if ( pClause->nLits == 0 ) fprintf( pFile, "Empty" ); fprintf( pFile, "\n" ); } Vec_PtrFree( vClaMap ); } //////////////////////////////////////////////////////////////////////// /// END OF FILE /// //////////////////////////////////////////////////////////////////////// ABC_NAMESPACE_IMPL_END