Experiments with support minimization.

src/aig/gia/gia.h

@@ -1470,6 +1470,10 @@ typedef struct Gia_ManMin_t_ Gia_ManMin_t;
 extern Gia_ManMin_t *      Gia_ManSuppStart( Gia_Man_t * pGia );
 extern void                Gia_ManSuppStop( Gia_ManMin_t * p );
 extern int                 Gia_ManSupportAnd( Gia_ManMin_t * p, int iLit0, int iLit1 );
+typedef struct Gia_Man2Min_t_ Gia_Man2Min_t;
+extern Gia_Man2Min_t *     Gia_Man2SuppStart( Gia_Man_t * pGia );
+extern void                Gia_Man2SuppStop( Gia_Man2Min_t * p );
+extern int                 Gia_Man2SupportAnd( Gia_Man2Min_t * p, int iLit0, int iLit1 );
 /*=== giaSweep.c ============================================================*/
 extern Gia_Man_t *         Gia_ManFraigSweepSimple( Gia_Man_t * p, void * pPars );
 extern Gia_Man_t *         Gia_ManSweepWithBoxes( Gia_Man_t * p, void * pParsC, void * pParsS, int fConst, int fEquiv, int fVerbose, int fVerbEquivs );

src/aig/gia/giaSupp.c

@@ -19,6 +19,8 @@
 ***********************************************************************/
 
 #include "gia.h"
+#include "sat/satoko/satoko.h"
+#include "sat/satoko/solver.h"
 
 #ifdef ABC_USE_CUDD
 #include "bdd/extrab/extraBdd.h"
@@ -329,6 +331,553 @@ Gia_Man_t * Gia_ManSupportAndTest( Gia_Man_t * pGia )
     return pNew;
 }
 
+
+
+
+struct Gia_Man2Min_t_ 
+{
+    // problem formulation
+    Gia_Man_t *     pGia;
+    int             iLits[2];
+    // structural information
+    Vec_Int_t *     vCis[2];
+    Vec_Int_t *     vObjs[2];
+    // SAT solving
+    satoko_t *      pSat;           // SAT solver
+    Vec_Wrd_t *     vSims;          // simulation
+    Vec_Ptr_t *     vFrontier;      // CNF construction
+    Vec_Ptr_t *     vFanins;        // CNF construction
+    Vec_Int_t *     vSatVars;       // nodes
+    int             nCisOld;        // previous number of CIs
+    int             iPattern;       // the next pattern to write
+    int             nSatSat;
+    int             nSatUnsat;
+    int             nCalls;
+    int             nSims;
+    int             nSupps;
+};
+
+static inline int    Gia_Min2ObjSatId( Gia_Man_t * p, Gia_Obj_t * pObj )             { return Gia_ObjCopyArray(p, Gia_ObjId(p, pObj));                                                        }
+static inline int    Gia_Min2ObjSetSatId( Gia_Man_t * p, Gia_Obj_t * pObj, int Num ) { assert(Gia_Min2ObjSatId(p, pObj) == -1); Gia_ObjSetCopyArray(p, Gia_ObjId(p, pObj), Num); return Num;  }
+static inline void   Gia_Min2ObjCleanSatId( Gia_Man_t * p, Gia_Obj_t * pObj )        { assert(Gia_Min2ObjSatId(p, pObj) != -1); Gia_ObjSetCopyArray(p, Gia_ObjId(p, pObj), -1);               }
+
+
+/**Function*************************************************************
+
+  Synopsis    [Create/delete the data representation manager.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+Gia_Man2Min_t * Gia_Man2SuppStart( Gia_Man_t * pGia )
+{
+    Gia_Man2Min_t * p;
+    p = ABC_CALLOC( Gia_Man2Min_t, 1 );
+    p->pGia      = pGia;
+    p->vCis[0]   = Vec_IntAlloc( 512 );
+    p->vCis[1]   = Vec_IntAlloc( 512 );
+    p->vObjs[0]  = Vec_IntAlloc( 512 );
+    p->vObjs[1]  = Vec_IntAlloc( 512 );
+    // SAT solving
+    p->pSat      = satoko_create();
+    p->vSims     = Vec_WrdAlloc( 1000 );
+    p->vFrontier = Vec_PtrAlloc( 1000 );
+    p->vFanins   = Vec_PtrAlloc( 100 );
+    p->vSatVars  = Vec_IntAlloc( 100 );
+    p->iPattern  = 1;
+    p->pSat->opts.learnt_ratio = 0; // prevent garbage collection
+    return p;
+}
+void Gia_Man2SuppStop( Gia_Man2Min_t * p )
+{
+    printf( "Total calls = %8d.  Supps = %6d.  Sims = %6d.   SAT = %6d.  UNSAT = %6d.\n", 
+        p->nCalls, p->nSupps, p->nSims, p->nSatSat, p->nSatUnsat );
+    Vec_IntFreeP( &p->vCis[0] );
+    Vec_IntFreeP( &p->vCis[1] );
+    Vec_IntFreeP( &p->vObjs[0] );
+    Vec_IntFreeP( &p->vObjs[1] );
+    Gia_ManCleanMark01( p->pGia );
+    satoko_destroy( p->pSat );
+    Vec_WrdFreeP( &p->vSims );
+    Vec_PtrFreeP( &p->vFrontier );
+    Vec_PtrFreeP( &p->vFanins );
+    Vec_IntFreeP( &p->vSatVars );
+    ABC_FREE( p );
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Adds clauses to the solver.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Gia_Min2AddClausesMux( Gia_Man_t * p, Gia_Obj_t * pNode, satoko_t * pSat )
+{
+    int fPolarFlip = 0;
+    Gia_Obj_t * pNodeI, * pNodeT, * pNodeE;
+    int pLits[4], RetValue, VarF, VarI, VarT, VarE, fCompT, fCompE;
+
+    assert( !Gia_IsComplement( pNode ) );
+    assert( pNode->fMark0 );
+    // get nodes (I = if, T = then, E = else)
+    pNodeI = Gia_ObjRecognizeMux( pNode, &pNodeT, &pNodeE );
+    // get the variable numbers
+    VarF = Gia_Min2ObjSatId(p, pNode);
+    VarI = Gia_Min2ObjSatId(p, pNodeI);
+    VarT = Gia_Min2ObjSatId(p, Gia_Regular(pNodeT));
+    VarE = Gia_Min2ObjSatId(p, Gia_Regular(pNodeE));
+    // get the complementation flags
+    fCompT = Gia_IsComplement(pNodeT);
+    fCompE = Gia_IsComplement(pNodeE);
+
+    // f = ITE(i, t, e)
+
+    // i' + t' + f
+    // i' + t  + f'
+    // i  + e' + f
+    // i  + e  + f'
+
+    // create four clauses
+    pLits[0] = Abc_Var2Lit(VarI, 1);
+    pLits[1] = Abc_Var2Lit(VarT, 1^fCompT);
+    pLits[2] = Abc_Var2Lit(VarF, 0);
+    if ( fPolarFlip )
+    {
+        if ( pNodeI->fPhase )               pLits[0] = Abc_LitNot( pLits[0] );
+        if ( Gia_Regular(pNodeT)->fPhase )  pLits[1] = Abc_LitNot( pLits[1] );
+        if ( pNode->fPhase )                pLits[2] = Abc_LitNot( pLits[2] );
+    }
+    RetValue = satoko_add_clause( pSat, pLits, 3 );
+    assert( RetValue );
+    pLits[0] = Abc_Var2Lit(VarI, 1);
+    pLits[1] = Abc_Var2Lit(VarT, 0^fCompT);
+    pLits[2] = Abc_Var2Lit(VarF, 1);
+    if ( fPolarFlip )
+    {
+        if ( pNodeI->fPhase )               pLits[0] = Abc_LitNot( pLits[0] );
+        if ( Gia_Regular(pNodeT)->fPhase )  pLits[1] = Abc_LitNot( pLits[1] );
+        if ( pNode->fPhase )                pLits[2] = Abc_LitNot( pLits[2] );
+    }
+    RetValue = satoko_add_clause( pSat, pLits, 3 );
+    assert( RetValue );
+    pLits[0] = Abc_Var2Lit(VarI, 0);
+    pLits[1] = Abc_Var2Lit(VarE, 1^fCompE);
+    pLits[2] = Abc_Var2Lit(VarF, 0);
+    if ( fPolarFlip )
+    {
+        if ( pNodeI->fPhase )               pLits[0] = Abc_LitNot( pLits[0] );
+        if ( Gia_Regular(pNodeE)->fPhase )  pLits[1] = Abc_LitNot( pLits[1] );
+        if ( pNode->fPhase )                pLits[2] = Abc_LitNot( pLits[2] );
+    }
+    RetValue = satoko_add_clause( pSat, pLits, 3 );
+    assert( RetValue );
+    pLits[0] = Abc_Var2Lit(VarI, 0);
+    pLits[1] = Abc_Var2Lit(VarE, 0^fCompE);
+    pLits[2] = Abc_Var2Lit(VarF, 1);
+    if ( fPolarFlip )
+    {
+        if ( pNodeI->fPhase )               pLits[0] = Abc_LitNot( pLits[0] );
+        if ( Gia_Regular(pNodeE)->fPhase )  pLits[1] = Abc_LitNot( pLits[1] );
+        if ( pNode->fPhase )                pLits[2] = Abc_LitNot( pLits[2] );
+    }
+    RetValue = satoko_add_clause( pSat, pLits, 3 );
+    assert( RetValue );
+
+    // two additional clauses
+    // t' & e' -> f'
+    // t  & e  -> f 
+
+    // t  + e   + f'
+    // t' + e'  + f 
+
+    if ( VarT == VarE )
+    {
+//        assert( fCompT == !fCompE );
+        return;
+    }
+
+    pLits[0] = Abc_Var2Lit(VarT, 0^fCompT);
+    pLits[1] = Abc_Var2Lit(VarE, 0^fCompE);
+    pLits[2] = Abc_Var2Lit(VarF, 1);
+    if ( fPolarFlip )
+    {
+        if ( Gia_Regular(pNodeT)->fPhase )  pLits[0] = Abc_LitNot( pLits[0] );
+        if ( Gia_Regular(pNodeE)->fPhase )  pLits[1] = Abc_LitNot( pLits[1] );
+        if ( pNode->fPhase )                pLits[2] = Abc_LitNot( pLits[2] );
+    }
+    RetValue = satoko_add_clause( pSat, pLits, 3 );
+    assert( RetValue );
+    pLits[0] = Abc_Var2Lit(VarT, 1^fCompT);
+    pLits[1] = Abc_Var2Lit(VarE, 1^fCompE);
+    pLits[2] = Abc_Var2Lit(VarF, 0);
+    if ( fPolarFlip )
+    {
+        if ( Gia_Regular(pNodeT)->fPhase )  pLits[0] = Abc_LitNot( pLits[0] );
+        if ( Gia_Regular(pNodeE)->fPhase )  pLits[1] = Abc_LitNot( pLits[1] );
+        if ( pNode->fPhase )                pLits[2] = Abc_LitNot( pLits[2] );
+    }
+    RetValue = satoko_add_clause( pSat, pLits, 3 );
+    assert( RetValue );
+}
+void Gia_Min2AddClausesSuper( Gia_Man_t * p, Gia_Obj_t * pNode, Vec_Ptr_t * vSuper, satoko_t * pSat )
+{
+    int fPolarFlip = 0;
+    Gia_Obj_t * pFanin;
+    int * pLits, nLits, RetValue, i;
+    assert( !Gia_IsComplement(pNode) );
+    assert( Gia_ObjIsAnd( pNode ) );
+    // create storage for literals
+    nLits = Vec_PtrSize(vSuper) + 1;
+    pLits = ABC_ALLOC( int, nLits );
+    // suppose AND-gate is A & B = C
+    // add !A => !C   or   A + !C
+    Vec_PtrForEachEntry( Gia_Obj_t *, vSuper, pFanin, i )
+    {
+        pLits[0] = Abc_Var2Lit(Gia_Min2ObjSatId(p, Gia_Regular(pFanin)), Gia_IsComplement(pFanin));
+        pLits[1] = Abc_Var2Lit(Gia_Min2ObjSatId(p, pNode), 1);
+        if ( fPolarFlip )
+        {
+            if ( Gia_Regular(pFanin)->fPhase )  pLits[0] = Abc_LitNot( pLits[0] );
+            if ( pNode->fPhase )                pLits[1] = Abc_LitNot( pLits[1] );
+        }
+        RetValue = satoko_add_clause( pSat, pLits, 2 );
+        assert( RetValue );
+    }
+    // add A & B => C   or   !A + !B + C
+    Vec_PtrForEachEntry( Gia_Obj_t *, vSuper, pFanin, i )
+    {
+        pLits[i] = Abc_Var2Lit(Gia_Min2ObjSatId(p, Gia_Regular(pFanin)), !Gia_IsComplement(pFanin));
+        if ( fPolarFlip )
+        {
+            if ( Gia_Regular(pFanin)->fPhase )  pLits[i] = Abc_LitNot( pLits[i] );
+        }
+    }
+    pLits[nLits-1] = Abc_Var2Lit(Gia_Min2ObjSatId(p, pNode), 0);
+    if ( fPolarFlip )
+    {
+        if ( pNode->fPhase )  pLits[nLits-1] = Abc_LitNot( pLits[nLits-1] );
+    }
+    RetValue = satoko_add_clause( pSat, pLits, nLits );
+    assert( RetValue );
+    ABC_FREE( pLits );
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Adds clauses and returns CNF variable of the node.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Gia_Min2CollectSuper_rec( Gia_Obj_t * pObj, Vec_Ptr_t * vSuper, int fFirst, int fUseMuxes )
+{
+    // if the new node is complemented or a PI, another gate begins
+    if ( Gia_IsComplement(pObj) || Gia_ObjIsCi(pObj) || 
+         (!fFirst && Gia_ObjValue(pObj) > 1) || 
+         (fUseMuxes && pObj->fMark0) )
+    {
+        Vec_PtrPushUnique( vSuper, pObj );
+        return;
+    }
+    // go through the branches
+    Gia_Min2CollectSuper_rec( Gia_ObjChild0(pObj), vSuper, 0, fUseMuxes );
+    Gia_Min2CollectSuper_rec( Gia_ObjChild1(pObj), vSuper, 0, fUseMuxes );
+}
+void Gia_Min2CollectSuper( Gia_Obj_t * pObj, int fUseMuxes, Vec_Ptr_t * vSuper )
+{
+    assert( !Gia_IsComplement(pObj) );
+    assert( !Gia_ObjIsCi(pObj) );
+    Vec_PtrClear( vSuper );
+    Gia_Min2CollectSuper_rec( pObj, vSuper, 1, fUseMuxes );
+}
+void Gia_Min2ObjAddToFrontier( Gia_Man_t * p, Gia_Obj_t * pObj, Vec_Ptr_t * vFrontier, satoko_t * pSat, Vec_Int_t * vSatVars )
+{
+    assert( !Gia_IsComplement(pObj) );
+    assert( !Gia_ObjIsConst0(pObj) );
+    if ( Gia_Min2ObjSatId(p, pObj) >= 0 )
+        return;
+    assert( Gia_Min2ObjSatId(p, pObj) == -1 );
+    Vec_IntPush( vSatVars, Gia_ObjId(p, pObj) );
+    Gia_Min2ObjSetSatId( p, pObj, satoko_add_variable(pSat, 0) );
+    if ( Gia_ObjIsAnd(pObj) )
+        Vec_PtrPush( vFrontier, pObj );
+}
+int Gia_Min2ObjGetCnfVar( Gia_Man2Min_t * p, int iObj )
+{ 
+    Gia_Obj_t * pObj = Gia_ManObj(p->pGia, iObj);
+    Gia_Obj_t * pNode, * pFanin;
+    int i, k, fUseMuxes = 1;
+    if ( Gia_Min2ObjSatId(p->pGia, pObj) >= 0 )
+        return Gia_Min2ObjSatId(p->pGia, pObj);
+    if ( Gia_ObjIsCi(pObj) )
+    {
+        Vec_IntPush( p->vSatVars, iObj );
+        return Gia_Min2ObjSetSatId( p->pGia, pObj, satoko_add_variable(p->pSat, 0) );
+    }
+    assert( Gia_ObjIsAnd(pObj) );
+    // start the frontier
+    Vec_PtrClear( p->vFrontier );
+    Gia_Min2ObjAddToFrontier( p->pGia, pObj, p->vFrontier, p->pSat, p->vSatVars );
+    // explore nodes in the frontier
+    Vec_PtrForEachEntry( Gia_Obj_t *, p->vFrontier, pNode, i )
+    {
+        assert( Gia_Min2ObjSatId(p->pGia,pNode) >= 0 );
+        if ( fUseMuxes && pNode->fMark0 )
+        {
+            Vec_PtrClear( p->vFanins );
+            Vec_PtrPushUnique( p->vFanins, Gia_ObjFanin0( Gia_ObjFanin0(pNode) ) );
+            Vec_PtrPushUnique( p->vFanins, Gia_ObjFanin0( Gia_ObjFanin1(pNode) ) );
+            Vec_PtrPushUnique( p->vFanins, Gia_ObjFanin1( Gia_ObjFanin0(pNode) ) );
+            Vec_PtrPushUnique( p->vFanins, Gia_ObjFanin1( Gia_ObjFanin1(pNode) ) );
+            Vec_PtrForEachEntry( Gia_Obj_t *, p->vFanins, pFanin, k )
+                Gia_Min2ObjAddToFrontier( p->pGia, Gia_Regular(pFanin), p->vFrontier, p->pSat, p->vSatVars );
+            Gia_Min2AddClausesMux( p->pGia, pNode, p->pSat );
+        }
+        else
+        {
+            Gia_Min2CollectSuper( pNode, fUseMuxes, p->vFanins );
+            Vec_PtrForEachEntry( Gia_Obj_t *, p->vFanins, pFanin, k )
+                Gia_Min2ObjAddToFrontier( p->pGia, Gia_Regular(pFanin), p->vFrontier, p->pSat, p->vSatVars );
+            Gia_Min2AddClausesSuper( p->pGia, pNode, p->vFanins, p->pSat );
+        }
+        assert( Vec_PtrSize(p->vFanins) > 1 );
+    }
+    return Gia_Min2ObjSatId(p->pGia,pObj);
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Returns 0 if the node is not a constant.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int Gia_Min2ManSimulate( Gia_Man2Min_t * p )
+{
+    word Sim0, Sim1; int n, i, iObj;
+    p->nSims++;
+    // add random values to new CIs
+    Vec_WrdFillExtra( p->vSims, Gia_ManObjNum(p->pGia), 0 );
+    for ( i = p->nCisOld; i < Gia_ManCiNum(p->pGia); i++ )
+        Vec_WrdWriteEntry( p->vSims, Gia_ManCiIdToId(p->pGia, i), Gia_ManRandomW( 0 ) << 1 );
+    p->nCisOld = Gia_ManCiNum(p->pGia);
+    // simulate internal nodes
+    for ( n = 0; n < 2; n++ )
+        Vec_IntForEachEntry( p->vObjs[n], iObj, i )
+        {
+            Gia_Obj_t * pObj = Gia_ManObj( p->pGia, iObj );
+            Sim0 = Vec_WrdEntry( p->vSims, Gia_ObjFaninId0p(p->pGia, pObj) );
+            Sim1 = Vec_WrdEntry( p->vSims, Gia_ObjFaninId1p(p->pGia, pObj) );
+            Sim0 = Gia_ObjFaninC0(pObj) ? ~Sim0 : Sim0;
+            Sim1 = Gia_ObjFaninC1(pObj) ? ~Sim1 : Sim1;
+            Vec_WrdWriteEntry( p->vSims, iObj, Sim0 & Sim1 );
+        }
+    Sim0 = Vec_WrdEntry( p->vSims, Abc_Lit2Var(p->iLits[0]) );
+    Sim1 = Vec_WrdEntry( p->vSims, Abc_Lit2Var(p->iLits[1]) );
+    Sim0 = Abc_LitIsCompl(p->iLits[0]) ? ~Sim0 : Sim0;
+    Sim1 = Abc_LitIsCompl(p->iLits[1]) ? ~Sim1 : Sim1;
+//    assert( (Sim0 & Sim1) != ~0 );
+    return (Sim0 & Sim1) == 0;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Internal simulation APIs.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline void Gia_Min2SimSetInputBit( Gia_Man2Min_t * p, int iObj, int Bit, int iPattern )
+{
+    word * pSim = Vec_WrdEntryP( p->vSims, iObj );
+    assert( iPattern > 0 && iPattern < 64 );
+    if ( Abc_InfoHasBit( (unsigned*)pSim, iPattern ) != Bit )
+        Abc_InfoXorBit( (unsigned*)pSim, iPattern );
+}
+int Gia_Min2ManSolve( Gia_Man2Min_t * p )
+{
+    int iObj0 = Abc_Lit2Var(p->iLits[0]);
+    int iObj1 = Abc_Lit2Var(p->iLits[1]);
+    int n, i, status, iVar0, iVar1, iTemp;
+    assert( iObj0 > 0 && iObj1 > 0 );
+//    Vec_IntForEachEntry( &p->pGia->vCopies, iTemp, i )
+//        assert( iTemp == -1 );
+    Vec_IntFillExtra( &p->pGia->vCopies, Gia_ManObjNum(p->pGia), -1 );
+    Vec_IntClear( p->vSatVars );
+    assert( solver_varnum(p->pSat) == 0 );
+    iVar0 = Gia_Min2ObjGetCnfVar( p, iObj0 );
+    iVar1 = Gia_Min2ObjGetCnfVar( p, iObj1 );
+    satoko_assump_push( p->pSat, Abc_Var2Lit(iVar0, Abc_LitIsCompl(p->iLits[0])) );
+    satoko_assump_push( p->pSat, Abc_Var2Lit(iVar1, Abc_LitIsCompl(p->iLits[1])) );
+    status = satoko_solve( p->pSat );
+    satoko_assump_pop( p->pSat );
+    satoko_assump_pop( p->pSat );
+    if ( status == SATOKO_SAT )
+    {
+        //printf( "Disproved %d %d\n", p->iLits[0], p->iLits[1] );
+        assert( Gia_Min2ManSimulate(p) == 1 );
+        for ( n = 0; n < 2; n++ )
+            Vec_IntForEachEntry( p->vCis[n], iTemp, i )
+                Gia_Min2SimSetInputBit( p, iTemp, var_polarity(p->pSat, Gia_Min2ObjSatId(p->pGia, Gia_ManObj(p->pGia, iTemp))) == LIT_TRUE, p->iPattern );
+        assert( Gia_Min2ManSimulate(p) == 0 );
+        p->iPattern = p->iPattern == 63 ? 1 : p->iPattern + 1;
+        p->nSatSat++;
+    }
+    //printf( "supp %d  node %d  vars %d\n", 
+    //    Vec_IntSize(p->vCis[0]) + Vec_IntSize(p->vCis[1]), 
+    //    Vec_IntSize(p->vObjs[0]) + Vec_IntSize(p->vObjs[1]),
+    //    Vec_IntSize(p->vSatVars) );
+    satoko_rollback( p->pSat );
+    Vec_IntForEachEntry( p->vSatVars, iTemp, i )
+        Gia_Min2ObjCleanSatId( p->pGia, Gia_ManObj(p->pGia, iTemp) );
+    return status == SATOKO_UNSAT;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Collect nodes.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline int Gia_Min2ManGatherSupp_rec( Gia_Man_t * p, int iObj, Vec_Int_t * vCis, Vec_Int_t * vObjs )
+{
+    int Val0, Val1;
+    Gia_Obj_t * pObj;
+    if ( Gia_ObjIsTravIdPreviousId(p, iObj) )
+        return 1;
+    if ( Gia_ObjIsTravIdCurrentId(p, iObj) )
+        return 0;
+    Gia_ObjSetTravIdCurrentId(p, iObj);
+    pObj = Gia_ManObj( p, iObj );
+    if ( Gia_ObjIsCi(pObj) )
+    {
+        Vec_IntPush( vCis, iObj );
+        return 0;
+    }
+    assert( Gia_ObjIsAnd(pObj) );
+    Val0 = Gia_Min2ManGatherSupp_rec( p, Gia_ObjFaninId0(pObj, iObj), vCis, vObjs );
+    Val1 = Gia_Min2ManGatherSupp_rec( p, Gia_ObjFaninId1(pObj, iObj), vCis, vObjs );
+    Vec_IntPush( vObjs, iObj );
+    return Val0 || Val1;
+}
+int Gia_Min2ManGatherSupp( Gia_Man2Min_t * p )
+{
+    int n, Overlap = 0;
+    p->nSupps++;
+    Gia_ManIncrementTravId( p->pGia );
+    for ( n = 0; n < 2; n++ )
+    {
+        Vec_IntClear( p->vCis[n] );
+        Vec_IntClear( p->vObjs[n] );
+        Gia_ManIncrementTravId( p->pGia );
+        Overlap = Gia_Min2ManGatherSupp_rec( p->pGia, Abc_Lit2Var(p->iLits[n]), p->vCis[n], p->vObjs[n] );
+        assert( n || !Overlap );
+    }
+    return Overlap;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Takes a literal and returns a support-minized literal.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int Gia_Man2SupportAnd( Gia_Man2Min_t * p, int iLit0, int iLit1 )
+{
+    p->nCalls++;
+    //return Gia_ManHashAnd( p->pGia, iLit0, iLit1 );
+    p->iLits[0] = iLit0;
+    p->iLits[1] = iLit1;
+    if ( iLit0 < 2 || iLit1 < 2 || Abc_Lit2Var(iLit0) == Abc_Lit2Var(iLit1) || Gia_ManHashLookupInt(p->pGia, iLit0, iLit1) || 
+         !Gia_Min2ManGatherSupp(p) || !Gia_Min2ManSimulate(p) || !Gia_Min2ManSolve(p) )
+        return Gia_ManHashAnd( p->pGia, iLit0, iLit1 );
+    //printf( "%d %d\n", iLit0, iLit1 );
+    p->nSatUnsat++;
+    return 0;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Testbench.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+Gia_Man_t * Gia_Man2SupportAndTest( Gia_Man_t * pGia )
+{
+    Gia_Man2Min_t * pMan;
+    Gia_Man_t * pNew, * pTemp;
+    Gia_Obj_t * pObj;
+    int i;
+    Gia_ManRandomW( 1 );
+    Gia_ManFillValue( pGia );
+    pNew = Gia_ManStart( Gia_ManObjNum(pGia) );
+    pNew->pName = Abc_UtilStrsav( pGia->pName );
+    pNew->pSpec = Abc_UtilStrsav( pGia->pSpec );
+    Gia_ManHashAlloc( pNew );
+    Gia_ManConst0(pGia)->Value = 0;
+    pMan = Gia_Man2SuppStart( pNew );
+    Gia_ManForEachObj1( pGia, pObj, i )
+    {
+        if ( Gia_ObjIsAnd(pObj) )
+        {
+//            pObj->Value = Gia_ManAppendAnd( pNew, Gia_ObjFanin0Copy(pObj), Gia_ObjFanin1Copy(pObj) );
+            pObj->Value = Gia_Man2SupportAnd( pMan, Gia_ObjFanin0Copy(pObj), Gia_ObjFanin1Copy(pObj) );
+        }
+        else if ( Gia_ObjIsCi(pObj) )
+            pObj->Value = Gia_ManAppendCi( pNew );
+        else if ( Gia_ObjIsCo(pObj) )
+            pObj->Value = Gia_ManAppendCo( pNew, Gia_ObjFanin0Copy(pObj) );
+        else assert( 0 );
+
+        //if ( i % 10000 == 0 )
+        //    printf( "%d\n", i );
+    }
+    Gia_Man2SuppStop( pMan );
+    Gia_ManSetRegNum( pNew, Gia_ManRegNum(pGia) );
+    pNew = Gia_ManCleanup( pTemp = pNew );
+    Gia_ManStop( pTemp );
+    return pNew;
+}
+
+
+
+
 ////////////////////////////////////////////////////////////////////////
 ///                       END OF FILE                                ///
 ////////////////////////////////////////////////////////////////////////