Enables FXCH to handle Distance-1 cubes (D1C) and Single Cube Containment (SCC)…

Enables FXCH to handle Distance-1 cubes (D1C) and Single Cube Containment (SCC) as by product of extraction.

D1C: Whenever they appear a constant divisor (x! + x)  will be created and handle as any other divisor.
SCC: Will be taken care of as soon as they appear.

src/opt/fxch/Fxch.h

@@ -112,6 +112,7 @@ struct Fxch_Man_t_
     Vec_Int_t*     vPairs;     /* cube pairs for the given double cube divisor */
     Vec_Int_t*     vCubeFree;  // cube-free divisor
     Vec_Int_t*     vDiv;       // selected divisor
+    Vec_Int_t*     vSCC;
 
     /* Statistics */
     abctime timeInit;   /* Initialization time */
@@ -145,6 +146,7 @@ int  Fxch_DivRemove( Fxch_Man_t* pFxchMan, int fUpdate, int fSingleCube, int fBa
 void Fxch_DivSepareteCubes( Vec_Int_t* vDiv, Vec_Int_t* vCube0, Vec_Int_t* vCube1 );
 int  Fxch_DivRemoveLits( Vec_Int_t* vCube0, Vec_Int_t* vCube1, Vec_Int_t* vDiv, int *fCompl );
 void Fxch_DivPrint( Fxch_Man_t* pFxchMan, int iDiv );
+int Fxch_DivIsNotConstant1( Vec_Int_t* vDiv );
 
 /*===== FxchMan.c ====================================================================================================*/
 Fxch_Man_t* Fxch_ManAlloc( Vec_Wec_t* vCubes );

src/opt/fxch/FxchDiv.c

@@ -457,6 +457,17 @@ void Fxch_DivPrint( Fxch_Man_t* pFxchMan,
     printf( "Divs =%8d  \n", Hsh_VecSize( pFxchMan->pDivHash ) );
 }
 
+int Fxch_DivIsNotConstant1( Vec_Int_t* vDiv )
+{
+    int Lit0 = Abc_Lit2Var( Vec_IntEntry( vDiv, 0 ) ),
+        Lit1 = Abc_Lit2Var( Vec_IntEntry( vDiv, 1 ) );
+
+    if ( ( Vec_IntSize( vDiv ) == 2 )  && ( Lit0 == Abc_LitNot( Lit1 ) ) )
+            return 0;
+
+    return 1;
+}
+
 ////////////////////////////////////////////////////////////////////////
 ///                       END OF FILE                                ///
 ////////////////////////////////////////////////////////////////////////

src/opt/fxch/FxchSCHashTable.c

@@ -182,10 +182,6 @@ static inline int Fxch_SCHashTableEntryCompare( Fxch_SCHashTable_t* pSCHashTable
     Vec_IntClear( &pSCHashTable->vSubCube0 );
     Vec_IntClear( &pSCHashTable->vSubCube1 );
 
-    if ( pSCData0->iLit1 == 0 && pSCData1->iLit1 == 0 &&
-         Vec_IntEntry( vCube0, pSCData0->iLit0 ) == Abc_LitNot( Vec_IntEntry( vCube1, pSCData1->iLit0 ) ) )
-        return 0;
-
     if ( pSCData0->iLit1 > 0 && pSCData1->iLit1 > 0 &&
          ( Vec_IntEntry( vCube0, pSCData0->iLit0 ) == Vec_IntEntry( vCube1, pSCData1->iLit0 ) ||
            Vec_IntEntry( vCube0, pSCData0->iLit0 ) == Vec_IntEntry( vCube1, pSCData1->iLit1 ) ||
@@ -270,14 +266,16 @@ int Fxch_SCHashTableInsert( Fxch_SCHashTable_t* pSCHashTable,
         if ( !Fxch_SCHashTableEntryCompare( pSCHashTable, vCubes, &( pEntry->SCData ), &( pNewEntry->SCData ) ) )
             continue;
 
-        if ( pEntry->SCData.iLit0 == 0 )
-        {
-            printf("[FXCH] SCC detected\n");
-            continue;
-        }
-        if ( pNewEntry->SCData.iLit0 == 0 )
+        if ( ( pEntry->SCData.iLit0 == 0 ) || ( pNewEntry->SCData.iLit0 == 0 ) )
         {
-            printf("[FXCH] SCC detected\n");
+            Vec_Int_t* vCube0 = Fxch_ManGetCube( pSCHashTable->pFxchMan, pEntry->SCData.iCube ),
+                     * vCube1 = Fxch_ManGetCube( pSCHashTable->pFxchMan, pEntry->SCData.iCube );
+ 
+            if ( Vec_IntSize( vCube0 ) > Vec_IntSize( vCube1 ) )
+                Vec_IntPush( pSCHashTable->pFxchMan->vSCC, pEntry->SCData.iCube );
+            else
+                Vec_IntPush( pSCHashTable->pFxchMan->vSCC, pNewEntry->SCData.iCube );
+
             continue;
         }