Integrating mfs2 package to work with boxes.

14 files changed, 617 insertions, 259 deletions

diff --git a/src/aig/gia/gia.h b/src/aig/gia/gia.h
index 8c6c2fb4..3c5d3569 100644
--- a/src/aig/gia/gia.h
+++ b/src/aig/gia/gia.h
@@ -483,6 +483,7 @@ static inline int          Gia_ObjCopyF( Gia_Man_t * p, int f, Gia_Obj_t * pObj
 static inline void         Gia_ObjSetCopyF( Gia_Man_t * p, int f, Gia_Obj_t * pObj, int iLit )  { Vec_IntWriteEntry(&p->vCopies, Gia_ManObjNum(p) * f + Gia_ObjId(p,pObj), iLit);  }
 static inline int          Gia_ObjCopyArray( Gia_Man_t * p, int iObj )                          { return Vec_IntEntry(&p->vCopies, iObj);                                          }
 static inline void         Gia_ObjSetCopyArray( Gia_Man_t * p, int iObj, int iLit )             { Vec_IntWriteEntry(&p->vCopies, iObj, iLit);                                      }
+static inline void         Gia_ManCleanCopyArray( Gia_Man_t * p )                               { Vec_IntFill( &p->vCopies, Gia_ManObjNum(p), -1 );                                }
 
 static inline int          Gia_ObjFanin0CopyF( Gia_Man_t * p, int f, Gia_Obj_t * pObj )         { return Abc_LitNotCond(Gia_ObjCopyF(p, f, Gia_ObjFanin0(pObj)), Gia_ObjFaninC0(pObj));   }
 static inline int          Gia_ObjFanin1CopyF( Gia_Man_t * p, int f, Gia_Obj_t * pObj )         { return Abc_LitNotCond(Gia_ObjCopyF(p, f, Gia_ObjFanin1(pObj)), Gia_ObjFaninC1(pObj));   }
@@ -1088,6 +1089,7 @@ extern Gia_Man_t *         Gia_ManDupOrderDfsChoices( Gia_Man_t * p );
 extern Gia_Man_t *         Gia_ManDupOrderDfsReverse( Gia_Man_t * p );
 extern Gia_Man_t *         Gia_ManDupOutputGroup( Gia_Man_t * p, int iOutStart, int iOutStop );
 extern Gia_Man_t *         Gia_ManDupOutputVec( Gia_Man_t * p, Vec_Int_t * vOutPres );
+extern Gia_Man_t *         Gia_ManDupSelectedOutputs( Gia_Man_t * p, Vec_Int_t * vOutsLeft );
 extern Gia_Man_t *         Gia_ManDupOrderAiger( Gia_Man_t * p );
 extern Gia_Man_t *         Gia_ManDupLastPis( Gia_Man_t * p, int nLastPis );
 extern Gia_Man_t *         Gia_ManDupFlip( Gia_Man_t * p, int * pInitState );
@@ -1345,6 +1347,7 @@ extern float               Gia_ManComputeSwitching( Gia_Man_t * p, int nFrames,
 extern Vec_Int_t *         Gia_ManComputeSwitchProbs( Gia_Man_t * pGia, int nFrames, int nPref, int fProbOne );
 extern Vec_Flt_t *         Gia_ManPrintOutputProb( Gia_Man_t * p );
 /*=== giaTim.c ===========================================================*/
+extern int                 Gia_ManBoxNum( Gia_Man_t * p );
 extern int                 Gia_ManIsSeqWithBoxes( Gia_Man_t * p );
 extern int                 Gia_ManIsNormalized( Gia_Man_t * p );
 extern Gia_Man_t *         Gia_ManDupNormalize( Gia_Man_t * p );
@@ -1353,7 +1356,9 @@ extern Gia_Man_t *         Gia_ManDupUnshuffleInputs( Gia_Man_t * p );
 extern int                 Gia_ManLevelWithBoxes( Gia_Man_t * p );
 extern int                 Gia_ManLutLevelWithBoxes( Gia_Man_t * p );
 extern void *              Gia_ManUpdateTimMan( Gia_Man_t * p, Vec_Int_t * vBoxPres );
+extern void *              Gia_ManUpdateTimMan2( Gia_Man_t * p, Vec_Int_t * vBoxesLeft );
 extern Gia_Man_t *         Gia_ManUpdateExtraAig( void * pTime, Gia_Man_t * pAig, Vec_Int_t * vBoxPres );
+extern Gia_Man_t *         Gia_ManUpdateExtraAig2( void * pTime, Gia_Man_t * pAig, Vec_Int_t * vBoxesLeft );
 extern Gia_Man_t *         Gia_ManDupCollapse( Gia_Man_t * p, Gia_Man_t * pBoxes, Vec_Int_t * vBoxPres );
 extern int                 Gia_ManVerifyWithBoxes( Gia_Man_t * pGia, void * pParsInit, char * pFileSpec );
 /*=== giaTruth.c ===========================================================*/
diff --git a/src/aig/gia/giaDup.c b/src/aig/gia/giaDup.c
index 0e1028e8..5d7a6cb3 100644
--- a/src/aig/gia/giaDup.c
+++ b/src/aig/gia/giaDup.c
@@ -254,6 +254,38 @@ Gia_Man_t * Gia_ManDupOutputVec( Gia_Man_t * p, Vec_Int_t * vOutPres )
 
 /**Function*************************************************************
 
+  Synopsis    [Duplicates AIG while putting objects in the DFS order.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+Gia_Man_t * Gia_ManDupSelectedOutputs( Gia_Man_t * p, Vec_Int_t * vOutsLeft )
+{
+    Gia_Man_t * pNew;
+    Gia_Obj_t * pObj;
+    int i, iOut;
+    assert( Gia_ManRegNum(p) == 0 );
+    assert( Gia_ManPoNum(p) >= Vec_IntSize(vOutsLeft) );
+    Gia_ManFillValue( p );
+    pNew = Gia_ManStart( Gia_ManObjNum(p) );
+    pNew->pName = Abc_UtilStrsav( p->pName );
+    pNew->pSpec = Abc_UtilStrsav( p->pSpec );
+    Gia_ManConst0(p)->Value = 0;
+    Gia_ManForEachPi( p, pObj, i )
+        pObj->Value = Gia_ManAppendCi(pNew);
+    Vec_IntForEachEntry( vOutsLeft, iOut, i )
+        Gia_ManDupOrderDfs_rec( pNew, p, Gia_ObjFanin0(Gia_ManPo(p, iOut)) );
+    Vec_IntForEachEntry( vOutsLeft, iOut, i )
+        pObj->Value = Gia_ManAppendCo( pNew, Gia_ObjFanin0Copy(Gia_ManPo(p, iOut)) );
+    return pNew;
+}
+
+/**Function*************************************************************
+
   Synopsis    [Duplicates the AIG in the DFS order.]
 
   Description []
diff --git a/src/aig/gia/giaFadds.c b/src/aig/gia/giaFadds.c
index 4e913687..7b463f42 100644
--- a/src/aig/gia/giaFadds.c
+++ b/src/aig/gia/giaFadds.c
@@ -538,7 +538,7 @@ Tim_Man_t * Gia_ManGenerateTim( int nPis, int nPos, int nBoxes, int nIns, int nO
     curPo = 0;
     for ( i = 0; i < nBoxes; i++ )
     {
-        Tim_ManCreateBox( pMan, curPo, nIns, curPi, nOuts, -1 );
+        Tim_ManCreateBox( pMan, curPo, nIns, curPi, nOuts, 0 );
         curPi += nOuts;
         curPo += nIns;
     }
diff --git a/src/aig/gia/giaMan.c b/src/aig/gia/giaMan.c
index 9fbf5844..31b7490c 100644
--- a/src/aig/gia/giaMan.c
+++ b/src/aig/gia/giaMan.c
@@ -105,6 +105,7 @@ void Gia_ManStop( Gia_Man_t * p )
     Vec_IntFreeP( &p->vBarBufs );
     Vec_IntFreeP( &p->vLevels );
     Vec_IntFreeP( &p->vTruths );
+    Vec_IntErase( &p->vCopies );
     Vec_IntFreeP( &p->vTtNums );
     Vec_IntFreeP( &p->vTtNodes );
     Vec_WrdFreeP( &p->vTtMemory );
diff --git a/src/aig/gia/giaMfs.c b/src/aig/gia/giaMfs.c
index 4f6e74a1..afd6bbd7 100644
--- a/src/aig/gia/giaMfs.c
+++ b/src/aig/gia/giaMfs.c
@@ -19,22 +19,15 @@
 ***********************************************************************/
 
 #include "gia.h"
-#include "bool/kit/kit.h"
 #include "opt/sfm/sfm.h"
 #include "misc/tim/tim.h"
 
 ABC_NAMESPACE_IMPL_START
 
-
 ////////////////////////////////////////////////////////////////////////
 ///                        DECLARATIONS                              ///
 ////////////////////////////////////////////////////////////////////////
 
-static word s_ElemVar  = ABC_CONST(0xAAAAAAAAAAAAAAAA);
-static word s_ElemVar2 = ABC_CONST(0xCCCCCCCCCCCCCCCC);
-
-extern int Kit_TruthToGia( Gia_Man_t * pMan, unsigned * pTruth, int nVars, Vec_Int_t * vMemory, Vec_Int_t * vLeaves, int fHash );
-
 ////////////////////////////////////////////////////////////////////////
 ///                     FUNCTION DEFINITIONS                         ///
 ////////////////////////////////////////////////////////////////////////
@@ -50,204 +43,139 @@ extern int Kit_TruthToGia( Gia_Man_t * pMan, unsigned * pTruth, int nVars, Vec_I
   SeeAlso     []
 
 ***********************************************************************/
-void Gia_ManExtractMfs_rec( Gia_Man_t * p, int iObj, Vec_Int_t * vId2Mfs, Vec_Wec_t * vFanins, Vec_Str_t * vFixed, Vec_Wrd_t * vTruths, Vec_Wrd_t * vTruthsTemp )
+Sfm_Ntk_t * Gia_ManExtractMfs( Gia_Man_t * p )
 {
+    Gia_Obj_t * pObj, * pObjExtra;
+    Vec_Wec_t * vFanins; // mfs data
+    Vec_Str_t * vFixed;  // mfs data 
+    Vec_Str_t * vEmpty;  // mfs data
+    Vec_Wrd_t * vTruths; // mfs data
     Vec_Int_t * vArray;
-    int i, Fanin;
-    Gia_Obj_t * pObj = Gia_ManObj( p, iObj );
-    assert( Gia_ObjIsLut(p, iObj) );
-    if ( !~pObj->Value )
-        return;
-    Gia_LutForEachFanin( p, iObj, Fanin, i )
-        Gia_ManExtractMfs_rec( p, Fanin, vId2Mfs, vFanins, vFixed, vTruths, vTruthsTemp );
-    pObj->Value = Vec_WecSize(vFanins);
-    vArray = Vec_WecPushLevel( vFanins );
-    Vec_IntGrow( vArray, Gia_ObjLutSize(p, iObj) );
-    Gia_LutForEachFanin( p, iObj, Fanin, i )
-        Vec_IntPush( vArray, Gia_ManObj(p, Fanin)->Value );
-    Vec_StrPush( vFixed, (char)0 );
-    Vec_WrdPush( vTruths, Gia_ObjComputeTruthTable6Lut(p, iObj, vTruthsTemp) );
-    Vec_IntWriteEntry( vId2Mfs, iObj, pObj->Value );
-}
-void Gia_ManExtractMfs_rec2( Gia_Man_t * p, int iObj, Vec_Int_t * vId2Mfs, Vec_Wec_t * vFanins, Vec_Str_t * vFixed, Vec_Wrd_t * vTruths )
-{
-    Vec_Int_t * vArray;
-    Gia_Obj_t * pObj = Gia_ManObj( p, iObj );
-    if ( Gia_ObjIsTravIdCurrent(p, pObj) )
-        return;
-    Gia_ObjSetTravIdCurrent(p, pObj);
-    assert( Gia_ObjIsAnd(pObj) );
-    Gia_ManExtractMfs_rec2( p, Gia_ObjFaninId0(pObj, iObj), vId2Mfs, vFanins, vFixed, vTruths );
-    Gia_ManExtractMfs_rec2( p, Gia_ObjFaninId1(pObj, iObj), vId2Mfs, vFanins, vFixed, vTruths );
-    pObj->Value = Vec_WecSize(vFanins);
-    vArray = Vec_WecPushLevel( vFanins );
-    Vec_IntGrow( vArray, 2 );
-    Vec_IntPush( vArray, Gia_ObjFanin0(pObj)->Value );
-    Vec_IntPush( vArray, Gia_ObjFanin1(pObj)->Value );
-    Vec_StrPush( vFixed, (char)1 );
-    Vec_WrdPush( vTruths, (Gia_ObjFaninC0(pObj) ? ~s_ElemVar : s_ElemVar) & (Gia_ObjFaninC1(pObj) ? ~s_ElemVar2 : s_ElemVar2) );
-    Vec_IntWriteEntry( vId2Mfs, iObj, pObj->Value );
-}
-Sfm_Ntk_t * Gia_ManExtractMfs( Gia_Man_t * p, Gia_Man_t * pBoxes, Vec_Int_t ** pvId2Mfs )
-{
+    Vec_Int_t * vLeaves;
+    word uTruth, uTruthVar = ABC_CONST(0xAAAAAAAAAAAAAAAA);
     Tim_Man_t * pManTime = (Tim_Man_t *)p->pManTime;
-    Vec_Int_t * vPoNodes;
-    Vec_Int_t * vId2Mfs;
-    Vec_Wec_t * vFanins;
-    Vec_Str_t * vFixed;
-    Vec_Wrd_t * vTruths, * vTruthsTemp;
-    Vec_Int_t * vArray;
-    Gia_Obj_t * pObj, * pObjBox;
-    int i, k, nRealPis, nRealPos, nPiNum, nPoNum, curCi, curCo;
-    assert( pManTime == NULL || Tim_ManCiNum(pManTime) == Gia_ManCiNum(p) );
-    assert( pManTime == NULL || Tim_ManCoNum(pManTime) == Gia_ManCoNum(p) );
-    // get the real number of PIs and POs
-    nRealPis = pManTime ? Tim_ManPiNum(pManTime) : Gia_ManCiNum(p);
-    nRealPos = pManTime ? Tim_ManPoNum(pManTime) : Gia_ManCoNum(p);
-    // create mapping from GIA into MFS
-    vId2Mfs  = Vec_IntStartFull( Gia_ManObjNum(p) );
-    // collect PO nodes
-    vPoNodes = Vec_IntAlloc( 1000 );
-    // create the arrays
-    vFanins  = Vec_WecAlloc( 1000 );
-    vFixed   = Vec_StrAlloc( 1000 );
-    vTruths  = Vec_WrdAlloc( 1000 );
-    vTruthsTemp = Vec_WrdStart( Gia_ManObjNum(p) );
-    // assign MFS ids to primary inputs
-    Gia_ManFillValue( p );
-    for ( i = 0; i < nRealPis; i++ )
+    int nBoxes   = Gia_ManBoxNum(p);
+    int nRealPis = nBoxes ? Tim_ManPiNum(pManTime) : Gia_ManPiNum(p);
+    int nRealPos = nBoxes ? Tim_ManPoNum(pManTime) : Gia_ManPoNum(p);
+    int i, k, curCi, curCo, nBoxIns, nBoxOuts;
+    int Id, iFan, nMfsVars, Counter = 0;
+    assert( !p->pAigExtra || Gia_ManPiNum(p->pAigExtra) <= 6 );
+    // prepare storage
+    nMfsVars = Gia_ManCiNum(p) + 1 + Gia_ManLutNum(p) + Gia_ManCoNum(p);
+    vFanins  = Vec_WecStart( nMfsVars );
+    vFixed   = Vec_StrStart( nMfsVars );
+    vEmpty   = Vec_StrStart( nMfsVars );
+    vTruths  = Vec_WrdStart( nMfsVars );
+    // set internal PIs
+    Gia_ManCleanCopyArray( p );
+    Gia_ManForEachCiId( p, Id, i )
+        Gia_ObjSetCopyArray( p, Id, Counter++ );
+    // set constant node
+    Vec_StrWriteEntry( vFixed, Counter, (char)1 );
+    Vec_WrdWriteEntry( vTruths, Counter, (word)0 );
+    Gia_ObjSetCopyArray( p, 0, Counter++ );
+    // set internal LUTs
+    vLeaves = Vec_IntAlloc( 6 );
+    Gia_ObjComputeTruthTableStart( p, 6 );
+    Gia_ManForEachLut( p, Id )
     {
-        pObj = Gia_ManPi( p, i );
-        pObj->Value = Vec_WecSize(vFanins);
-        Vec_WecPushLevel( vFanins );
-        Vec_StrPush( vFixed, (char)0 );
-        Vec_WrdPush( vTruths, (word)0 );
-        Vec_IntWriteEntry( vId2Mfs, Gia_ObjId(p, pObj), pObj->Value );
-    }
-    // assign MFS ids to black box outputs
-    curCi = nRealPis;
-    curCo = 0;
-    if ( pManTime )
-    for ( i = 0; i < Tim_ManBoxNum(pManTime); i++ )
-    {
-        if ( !Tim_ManBoxIsBlack(pManTime, i) )
+        Vec_IntClear( vLeaves );
+        vArray = Vec_WecEntry( vFanins, Counter );
+        Vec_IntGrow( vArray, Gia_ObjLutSize(p, Id) );
+        Gia_LutForEachFanin( p, Id, iFan, k )
         {
-            // collect POs
-            for ( k = 0; k < Tim_ManBoxInputNum(pManTime, i); k++ )
-            {
-                pObj = Gia_ManPo( p, curCo + k );
-                Vec_IntPush( vPoNodes, Gia_ObjId(p, pObj) );
-            }
-            // assign values to the PIs
-            for ( k = 0; k < Tim_ManBoxOutputNum(pManTime, i); k++ )
-            {
-                pObj = Gia_ManPi( p, curCi + k );
-                pObj->Value = Vec_WecSize(vFanins);
-                Vec_WecPushLevel( vFanins );
-                Vec_StrPush( vFixed, (char)1 );
-                Vec_WrdPush( vTruths, (word)0 );
-                Vec_IntWriteEntry( vId2Mfs, Gia_ObjId(p, pObj), pObj->Value );
-            }
+            assert( Gia_ObjCopyArray(p, iFan) >= 0 );
+            Vec_IntPush( vArray, Gia_ObjCopyArray(p, iFan) );
+            Vec_IntPush( vLeaves, iFan );
         }
-        curCo += Tim_ManBoxInputNum(pManTime, i);
-        curCi += Tim_ManBoxOutputNum(pManTime, i);
+        assert( Vec_IntSize(vLeaves) <= 6 );
+        assert( Vec_IntSize(vLeaves) == Gia_ObjLutSize(p, Id) );
+        uTruth = *Gia_ObjComputeTruthTableCut( p, Gia_ManObj(p, Id), vLeaves );
+        Vec_WrdWriteEntry( vTruths, Counter, uTruth );
+        Gia_ObjSetCopyArray( p, Id, Counter++ );
     }
-    // collect POs
-//    for ( i = Tim_ManCoNum(pManTime) - Tim_ManPoNum(pManTime); i < Tim_ManCoNum(pManTime); i++ )
-    for ( i = Gia_ManCoNum(p) - nRealPos; i < Gia_ManCoNum(p); i++ )
-    {
-        pObj = Gia_ManPo( p, i );
-        Vec_IntPush( vPoNodes, Gia_ObjId(p, pObj) );
-    }
-    curCo += nRealPos;
-    // verify counts
-    assert( curCi == Gia_ManPiNum(p) );
-    assert( curCo == Gia_ManPoNum(p) );
-    // remeber the end of PIs
-    nPiNum = Vec_WecSize(vFanins);
-    nPoNum = Vec_IntSize(vPoNodes);
-    // assign value to constant node
-    pObj = Gia_ManConst0(p);
-    Vec_IntWriteEntry( vId2Mfs, Gia_ObjId(p, pObj), Vec_WecSize(vFanins) );
-    pObj->Value = Vec_WecSize(vFanins);
-    Vec_WecPushLevel( vFanins );
-    Vec_StrPush( vFixed, (char)0 );
-    Vec_WrdPush( vTruths, (word)0 );
-    Vec_IntWriteEntry( vId2Mfs, Gia_ObjId(p, pObj), pObj->Value );
-    // create internal nodes
-    curCi = nRealPis;
-    curCo = 0;
-    if ( pManTime )
-    for ( i = 0; i < Tim_ManBoxNum(pManTime); i++ )
+    Gia_ObjComputeTruthTableStop( p );
+    // set all POs
+    Gia_ManForEachCo( p, pObj, i )
     {
-        // recursively add for box inputs
-        Gia_ManIncrementTravId( pBoxes );
-        for ( k = 0; k < Tim_ManBoxInputNum(pManTime, i); k++ )
+        iFan = Gia_ObjFaninId0p( p, pObj );
+        assert( Gia_ObjCopyArray(p, iFan) >= 0 );
+        vArray = Vec_WecEntry( vFanins, Counter );
+        Vec_IntFill( vArray, 1, Gia_ObjCopyArray(p, iFan) );
+        if ( i < Gia_ManCoNum(p) - nRealPos ) // internal PO
         {
-            // build logic
-            pObj = Gia_ManPo( p, curCo + k );
-            Gia_ManExtractMfs_rec( p, Gia_ObjFaninId0p(p, pObj), vId2Mfs, vFanins, vFixed, vTruths, vTruthsTemp );
-            // add buffer/inverter
-            pObj->Value = Vec_WecSize(vFanins);
-            vArray = Vec_WecPushLevel( vFanins );
-            Vec_IntGrow( vArray, 1 );
-            assert( !~Gia_ObjFanin0(pObj)->Value );
-            Vec_IntPush( vArray, Gia_ObjFanin0(pObj)->Value );
-            Vec_StrPush( vFixed, (char)0 );
-            Vec_WrdPush( vTruths, Gia_ObjFaninC0(pObj) ? ~s_ElemVar : s_ElemVar );
-            Vec_IntWriteEntry( vId2Mfs, Gia_ObjId(p, pObj), pObj->Value );
-            // transfer to the PI
-            pObjBox = Gia_ManPi( pBoxes, k );
-            pObjBox->Value = pObj->Value;
-            Gia_ObjSetTravIdCurrent( pBoxes, pObjBox );
+            Vec_StrWriteEntry( vFixed, Counter, (char)1 );
+            Vec_StrWriteEntry( vEmpty, Counter, (char)1 );
+            uTruth = Gia_ObjFaninC0(pObj) ? ~uTruthVar: uTruthVar;
+            Vec_WrdWriteEntry( vTruths, Counter, uTruth );
         }
-        if ( !Tim_ManBoxIsBlack(pManTime, i) )
+        Gia_ObjSetCopyArray( p, Gia_ObjId(p, pObj), Counter++ );
+    }
+    assert( Counter == nMfsVars );
+    // add functions of the boxes
+    if ( p->pAigExtra )
+    {
+        Gia_ObjComputeTruthTableStart( p->pAigExtra, 6 );
+        curCi = nRealPis;
+        curCo = 0;
+        for ( i = 0; i < nBoxes; i++ )
         {
-            pObjBox = Gia_ManConst0(pBoxes);
-            pObjBox->Value = Vec_WecSize(vFanins);
-            Vec_WecPushLevel( vFanins );
-            Vec_StrPush( vFixed, (char)0 );
-            Vec_WrdPush( vTruths, (word)0 );
-            Gia_ObjSetTravIdCurrent( pBoxes, pObjBox );
-            // add internal nodes and transfer
-            for ( k = 0; k < Tim_ManBoxOutputNum(pManTime, i); k++ )
+            assert( !Tim_ManBoxIsBlack(pManTime, i) );
+            nBoxIns = Tim_ManBoxInputNum( pManTime, i );
+            nBoxOuts = Tim_ManBoxOutputNum( pManTime, i );
+            // collect truth table leaves
+            Vec_IntClear( vLeaves );
+            for ( k = 0; k < nBoxIns; k++ )
+                Vec_IntPush( vLeaves, Gia_ObjId(p->pAigExtra, Gia_ManCi(p->pAigExtra, k)) );
+            // iterate through box outputs
+            for ( k = 0; k < nBoxOuts; k++ )
             {
-                // build logic
-                pObjBox = Gia_ManPo( pBoxes, curCi - Tim_ManPiNum(pManTime) + k );
-                Gia_ManExtractMfs_rec2( pBoxes, Gia_ObjFaninId0p(pBoxes, pObjBox), vId2Mfs, vFanins, vFixed, vTruths );
-                // add buffer/inverter
-                vArray = Vec_WecPushLevel( vFanins );
-                Vec_IntGrow( vArray, 1 );
-                assert( !~Gia_ObjFanin0(pObjBox)->Value );
-                Vec_IntPush( vArray, Gia_ObjFanin0(pObjBox)->Value );
-                Vec_StrPush( vFixed, (char)1 );
-                Vec_WrdPush( vTruths, Gia_ObjFaninC0(pObjBox) ? ~s_ElemVar : s_ElemVar );
-                // transfer to the PI
-                pObj = Gia_ManPi( p, curCi + k );
-                pObj->Value = pObjBox->Value;
+                // CI corresponding to the box outputs
+                pObj = Gia_ManCi( p, curCi + k );
+                Counter = Gia_ObjCopyArray( p, Gia_ObjId(p, pObj) );
+                //printf( "%d ", Counter );
+                // box output in the extra manager
+                pObjExtra = Gia_ManCo( p->pAigExtra, curCi - nRealPis + k );
+                // compute truth table
+                if ( Gia_ObjFaninId0p(p->pAigExtra, pObjExtra) == 0 )
+                    uTruth = 0;
+                else
+                    uTruth = *Gia_ObjComputeTruthTableCut( p->pAigExtra, Gia_ObjFanin0(pObjExtra), vLeaves );
+                uTruth = Gia_ObjFaninC0(pObjExtra) ? ~uTruth : uTruth;
+                Vec_WrdWriteEntry( vTruths, Counter, uTruth );
+                // add box inputs (POs of the AIG) as fanins
+                vArray = Vec_WecEntry( vFanins, Counter );
+                Vec_IntGrow( vArray, nBoxIns );
+                for ( k = 0; k < nBoxIns; k++ )
+                {
+                    iFan = Gia_ObjId( p, Gia_ManCo(p, curCo + k) );
+                    assert( Gia_ObjCopyArray(p, iFan) >= 0 );
+                    Vec_IntPush( vArray, Gia_ObjCopyArray(p, iFan) );
+                }
+                Vec_StrWriteEntry( vFixed, Counter, (char)1 );
             }
+            // set internal POs pointing directly to internal PIs as no-delay
+            for ( k = 0; k < nBoxIns; k++ )
+            {
+                pObj = Gia_ManCo( p, curCo + k );
+                if ( !Gia_ObjIsCi( Gia_ObjFanin0(pObj) ) )
+                    continue;
+                Counter = Gia_ObjCopyArray( p, Gia_ObjFaninId0p(p, pObj) );
+                Vec_StrWriteEntry( vEmpty, Counter, (char)1 );
+            }
+            curCo += nBoxIns;
+            curCi += nBoxOuts;
         }
-        curCo += Tim_ManBoxInputNum(pManTime, i);
-        curCi += Tim_ManBoxOutputNum(pManTime, i);
-    }
-    // create POs with buffers
-    Gia_ManForEachObjVec( vPoNodes, p, pObj, i )
-    {
-        Gia_ManExtractMfs_rec( p, Gia_ObjFaninId0p(p, pObj), vId2Mfs, vFanins, vFixed, vTruths, vTruthsTemp );
-        pObj->Value = Vec_WecSize(vFanins);
-        // add buffer/inverter
-        vArray = Vec_WecPushLevel( vFanins );
-        Vec_IntGrow( vArray, 1 );
-        assert( !~Gia_ObjFanin0(pObj)->Value );
-        Vec_IntPush( vArray, Gia_ObjFanin0(pObj)->Value );
-        Vec_StrPush( vFixed, (char)0 );
-        Vec_WrdPush( vTruths, Gia_ObjFaninC0(pObj) ? ~s_ElemVar : s_ElemVar );
-        Vec_IntWriteEntry( vId2Mfs, Gia_ObjId(p, pObj), pObj->Value );
+        curCo += nRealPos;
+        Gia_ObjComputeTruthTableStop( p->pAigExtra );
+        // verify counts
+        assert( curCi == Gia_ManCiNum(p) );
+        assert( curCo == Gia_ManCoNum(p) );
+        assert( curCi - nRealPis == Gia_ManCoNum(p->pAigExtra) );
     }
-    Vec_IntFree( vPoNodes );
-    Vec_WrdFree( vTruthsTemp );
-    *pvId2Mfs = vId2Mfs;
-    return Sfm_NtkConstruct( vFanins, nPiNum, nPoNum, vFixed, NULL, vTruths );
+    // finalize 
+    Vec_IntFree( vLeaves );
+    return Sfm_NtkConstruct( vFanins, nRealPis, nRealPos, vFixed, vEmpty, vTruths );
 }
 
 /**Function*************************************************************
@@ -261,72 +189,159 @@ Sfm_Ntk_t * Gia_ManExtractMfs( Gia_Man_t * p, Gia_Man_t * pBoxes, Vec_Int_t ** p
   SeeAlso     []
 
 ***********************************************************************/
-Gia_Man_t * Gia_ManInsertMfs( Gia_Man_t * p, Sfm_Ntk_t * pNtk, Vec_Int_t * vId2Mfs )
+Gia_Man_t * Gia_ManInsertMfs( Gia_Man_t * p, Sfm_Ntk_t * pNtk )
 {
-    Gia_Man_t * pNew;
-    Gia_Obj_t * pObj;
-    Vec_Int_t * vMfsTopo, * vMfs2New, * vArray, * vCover;
-    int i, k, Fanin, iMfsId, iLitNew;
-    word * pTruth;
-    // collect MFS nodes in the topo order
-    vMfsTopo = Sfm_NtkDfs( pNtk );
-    // create mapping from MFS to new GIA literals
-    vMfs2New = Vec_IntStartFull( Vec_IntCap(vMfsTopo) );
+    extern int Gia_ManFromIfLogicCreateLut( Gia_Man_t * pNew, word * pRes, Vec_Int_t * vLeaves, Vec_Int_t * vCover, Vec_Int_t * vMapping, Vec_Int_t * vMapping2 );
+    Gia_Man_t * pNew;  Gia_Obj_t * pObj;
+    Tim_Man_t * pManTime = (Tim_Man_t *)p->pManTime;
+    int nBoxes   = Gia_ManBoxNum(p);
+    int nRealPis = nBoxes ? Tim_ManPiNum(pManTime) : Gia_ManPiNum(p);
+    int nRealPos = nBoxes ? Tim_ManPoNum(pManTime) : Gia_ManPoNum(p);
+    int i, k, Id, curCi, curCo, nBoxIns, nBoxOuts, iLitNew, iMfsId, iGroup, Fanin;
+    int nMfsNodes = 1 + Gia_ManCiNum(p) + Gia_ManLutNum(p) + Gia_ManCoNum(p);
+    word * pTruth, uTruthVar = ABC_CONST(0xAAAAAAAAAAAAAAAA);
+    Vec_Wec_t * vGroups = Vec_WecStart( nBoxes );
+    Vec_Int_t * vMfs2Gia = Vec_IntStartFull( nMfsNodes );
+    Vec_Int_t * vGroupMap = Vec_IntStartFull( nMfsNodes );
+    Vec_Int_t * vMfsTopo, * vCover, * vBoxesLeft;
+    Vec_Int_t * vArray, * vLeaves;
+    Vec_Int_t * vMapping, * vMapping2;
+    // collect nodes
+    curCi = nRealPis;
+    curCo = 0;
+    for ( i = 0; i < nBoxes; i++ )
+    {
+        nBoxIns = Tim_ManBoxInputNum( pManTime, i );
+        nBoxOuts = Tim_ManBoxOutputNum( pManTime, i );
+        vArray = Vec_WecEntry( vGroups, i );
+        for ( k = 0; k < nBoxIns; k++ )
+        {
+            pObj = Gia_ManCo( p, curCo + k );
+            iMfsId = Gia_ObjCopyArray( p, Gia_ObjId(p, pObj) );
+            assert( iMfsId > 0 );
+            Vec_IntPush( vArray, iMfsId );
+            Vec_IntWriteEntry( vGroupMap, iMfsId, Abc_Var2Lit(i,0) );
+        }
+        for ( k = 0; k < nBoxOuts; k++ )
+        {
+            pObj = Gia_ManCi( p, curCi + k );
+            iMfsId = Gia_ObjCopyArray( p, Gia_ObjId(p, pObj) );
+            assert( iMfsId > 0 );
+            Vec_IntPush( vArray, iMfsId );
+            Vec_IntWriteEntry( vGroupMap, iMfsId, Abc_Var2Lit(i,1) );
+        }
+        curCo += nBoxIns;
+        curCi += nBoxOuts;
+    }
+    curCo += nRealPos;
+    assert( curCi == Gia_ManCiNum(p) );
+    assert( curCo == Gia_ManCoNum(p) );
+
+    // collect nodes in the given order
+    vBoxesLeft = Vec_IntAlloc( nBoxes );
+    vMfsTopo = Sfm_NtkDfs( pNtk, vGroups, vGroupMap, vBoxesLeft );
+    assert( Vec_IntSize(vBoxesLeft) <= nBoxes );
+    assert( Vec_IntSize(vMfsTopo) > 0 );
+
     // start new GIA
     pNew = Gia_ManStart( Gia_ManObjNum(p) );
     pNew->pName = Abc_UtilStrsav( p->pName );
     pNew->pSpec = Abc_UtilStrsav( p->pSpec );
+
+    // start mapping
+    vMapping  = Vec_IntStart( Gia_ManObjNum(p) );
+    vMapping2 = Vec_IntStart( 1 );
+    // create const LUT
+    Vec_IntWriteEntry( vMapping, 0, Vec_IntSize(vMapping2) );
+    Vec_IntPush( vMapping2, 0 );
+    Vec_IntPush( vMapping2, 0 );
+
+    // map constant
+    Vec_IntWriteEntry( vMfs2Gia, Gia_ObjCopyArray(p, 0), 0 );
     // map primary inputs
-    Gia_ManForEachCi( p, pObj, i )
-    {
-        iMfsId = Vec_IntEntry( vId2Mfs, Gia_ObjId(p, pObj) );
-        assert( iMfsId >= 0 );
-        Vec_IntWriteEntry( vMfs2New, iMfsId, Gia_ManAppendCi(pNew) );
-    }
+    Gia_ManForEachCiId( p, Id, i )
+        if ( i < nRealPis )
+            Vec_IntWriteEntry( vMfs2Gia, Gia_ObjCopyArray(p, Id), Gia_ManAppendCi(pNew) );
     // map internal nodes
+    vLeaves = Vec_IntAlloc( 6 );
     vCover = Vec_IntAlloc( 1 << 16 );
     Vec_IntForEachEntry( vMfsTopo, iMfsId, i )
     {
-        assert( Sfm_NodeReadUsed(pNtk, iMfsId) );
         pTruth = Sfm_NodeReadTruth( pNtk, iMfsId );
-        if ( pTruth[0] == 0 || ~pTruth[0] == 0 )
-        {
-            Vec_IntWriteEntry( vMfs2New, iMfsId, 0 );
-            continue;
-        }
+        iGroup = Vec_IntEntry( vGroupMap, iMfsId );
         vArray = Sfm_NodeReadFanins( pNtk, iMfsId ); // belongs to pNtk
+        Vec_IntClear( vLeaves );
         Vec_IntForEachEntry( vArray, Fanin, k )
         {
-            iLitNew = Vec_IntEntry( vMfs2New, Fanin );
-            assert( iLitNew >= 0 );
-            Vec_IntWriteEntry( vArray, k, iLitNew );            
+            iLitNew = Vec_IntEntry( vMfs2Gia, Fanin );  assert( iLitNew >= 0 );
+            Vec_IntPush( vLeaves, iLitNew );            
+        }
+        if ( iGroup == -1 ) // internal node
+        {
+            assert( Sfm_NodeReadUsed(pNtk, iMfsId) );
+            iLitNew = Gia_ManFromIfLogicCreateLut( pNew, pTruth, vLeaves, vCover, vMapping, vMapping2 );
         }
-        // derive new function
-        iLitNew = Kit_TruthToGia( pNew, (unsigned *)pTruth, Vec_IntSize(vArray), vCover, vArray, 0 );
-        Vec_IntWriteEntry( vMfs2New, iMfsId, iLitNew );
+        else if ( Abc_LitIsCompl(iGroup) ) // internal CI
+            iLitNew = Gia_ManAppendCi( pNew );
+        else // internal CO
+        {
+            iLitNew = Gia_ManAppendCo( pNew, Abc_LitNotCond(Vec_IntEntry(vLeaves, 0), pTruth[0] == ~uTruthVar) );
+            //printf("Group = %d. po = %d\n", iGroup>>1, iMfsId );
+        }
+        Vec_IntWriteEntry( vMfs2Gia, iMfsId, iLitNew );
     }
     Vec_IntFree( vCover );
-    // map output nodes
+    Vec_IntFree( vLeaves );
+
+    // map primary outputs
     Gia_ManForEachCo( p, pObj, i )
     {
-        iMfsId = Vec_IntEntry( vId2Mfs, Gia_ObjId(p, pObj) );
-        assert( iMfsId >= 0 );
-        vArray = Sfm_NodeReadFanins( pNtk, iMfsId ); // belongs to pNtk
-        assert( Vec_IntSize(vArray) == 1 );
-        // get the fanin
-        iLitNew = Vec_IntEntry( vMfs2New, Vec_IntEntry(vArray, 0) );
+        if ( i < Gia_ManCoNum(p) - nRealPos ) // internal COs
+        {
+            iMfsId = Gia_ObjCopyArray( p, Gia_ObjId(p, pObj) );
+            iGroup = Vec_IntEntry( vGroupMap, iMfsId );
+            if ( Vec_IntFind(vMfsTopo, iGroup) >= 0 )
+            {
+                iLitNew = Vec_IntEntry( vMfs2Gia, iMfsId );
+                assert( iLitNew >= 0 );
+            }
+            continue;
+        }
+        iLitNew = Vec_IntEntry( vMfs2Gia, Gia_ObjCopyArray(p, Gia_ObjFaninId0p(p, pObj)) );
         assert( iLitNew >= 0 );
-        // create CO
-        pTruth = Sfm_NodeReadTruth( pNtk, iMfsId );
-        assert( pTruth[0] == s_ElemVar || ~pTruth[0] == s_ElemVar );
-        Gia_ManAppendCo( pNew, Abc_LitNotCond(iLitNew, (int)(pTruth[0] != s_ElemVar)) );
+        Gia_ManAppendCo( pNew, Abc_LitNotCond(iLitNew, Gia_ObjFaninC0(pObj)) );
     }
-    Vec_IntFree( vMfs2New );
+
+    // finish mapping 
+    if ( Vec_IntSize(vMapping) > Gia_ManObjNum(pNew) )
+        Vec_IntShrink( vMapping, Gia_ManObjNum(pNew) );
+    else
+        Vec_IntFillExtra( vMapping, Gia_ManObjNum(pNew), 0 );
+    assert( Vec_IntSize(vMapping) == Gia_ManObjNum(pNew) );
+    Vec_IntForEachEntry( vMapping, iLitNew, i )
+        if ( iLitNew > 0 )
+            Vec_IntAddToEntry( vMapping, i, Gia_ManObjNum(pNew) );
+    Vec_IntAppend( vMapping, vMapping2 );
+    Vec_IntFree( vMapping2 );
+    assert( pNew->vMapping == NULL );
+    pNew->vMapping = vMapping;
+
+    // create new timing manager and extra AIG
+    if ( pManTime )
+        pNew->pManTime = Gia_ManUpdateTimMan2( p, vBoxesLeft );
+    // update extra STG
+    if ( p->pAigExtra )
+        pNew->pAigExtra = Gia_ManUpdateExtraAig2( p->pManTime, p->pAigExtra, vBoxesLeft );
+
+    // cleanup
+    Vec_WecFree( vGroups );
     Vec_IntFree( vMfsTopo );
+    Vec_IntFree( vGroupMap );
+    Vec_IntFree( vMfs2Gia );
+    Vec_IntFree( vBoxesLeft );
     return pNew;
 }
 
-
 /**Function*************************************************************
 
   Synopsis    []
@@ -341,7 +356,6 @@ Gia_Man_t * Gia_ManInsertMfs( Gia_Man_t * p, Sfm_Ntk_t * pNtk, Vec_Int_t * vId2M
 Gia_Man_t * Gia_ManPerformMfs( Gia_Man_t * p, Sfm_Par_t * pPars )
 {
     Sfm_Ntk_t * pNtk;
-    Vec_Int_t * vId2Mfs;
     Gia_Man_t * pNew;
     int nFaninMax, nNodes;
     assert( Gia_ManRegNum(p) == 0 );
@@ -359,32 +373,29 @@ Gia_Man_t * Gia_ManPerformMfs( Gia_Man_t * p, Sfm_Par_t * pPars )
         return NULL;
     }
     // collect information
-    pNtk = Gia_ManExtractMfs( p, p->pAigExtra, &vId2Mfs );
+    pNtk = Gia_ManExtractMfs( p );
     // perform optimization
     nNodes = Sfm_NtkPerform( pNtk, pPars );
-    // call the fast extract procedure
     if ( nNodes == 0 )
     {
         Abc_Print( 1, "The network is not changed by \"&mfs\".\n" );
         pNew = Gia_ManDup( p );
         pNew->vMapping = Vec_IntDup( p->vMapping );
+        Gia_ManTransferTiming( pNew, p );
     }
     else
     {
-        pNew = Gia_ManInsertMfs( p, pNtk, vId2Mfs );
+        pNew = Gia_ManInsertMfs( p, pNtk );
         if( pPars->fVerbose )
             Abc_Print( 1, "The network has %d nodes changed by \"&mfs\".\n", nNodes );
     }
-    Vec_IntFree( vId2Mfs );
     Sfm_NtkFree( pNtk );
     return pNew;
 }
 
-
 ////////////////////////////////////////////////////////////////////////
 ///                       END OF FILE                                ///
 ////////////////////////////////////////////////////////////////////////
 
-
 ABC_NAMESPACE_IMPL_END
 
diff --git a/src/aig/gia/giaTim.c b/src/aig/gia/giaTim.c
index 156f67b1..c9d55ffc 100644
--- a/src/aig/gia/giaTim.c
+++ b/src/aig/gia/giaTim.c
@@ -35,6 +35,22 @@ ABC_NAMESPACE_IMPL_START
 
 /**Function*************************************************************
 
+  Synopsis    [Returns the number of boxes in the AIG with boxes.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int Gia_ManBoxNum( Gia_Man_t * p )
+{
+    return p->pManTime ? Tim_ManBoxNum((Tim_Man_t *)p->pManTime) : 0;
+}
+
+/**Function*************************************************************
+
   Synopsis    [Returns one if this is a seq AIG with non-trivial boxes.]
 
   Description []
@@ -598,9 +614,16 @@ void * Gia_ManUpdateTimMan( Gia_Man_t * p, Vec_Int_t * vBoxPres )
 {
     Tim_Man_t * pManTime = (Tim_Man_t *)p->pManTime;
     assert( pManTime != NULL );
-    assert( Tim_ManBoxNum(pManTime) == Vec_IntSize(vBoxPres) );
+    assert( Vec_IntSize(vBoxPres) == Tim_ManBoxNum(pManTime) );
     return Tim_ManTrim( pManTime, vBoxPres );
 }
+void * Gia_ManUpdateTimMan2( Gia_Man_t * p, Vec_Int_t * vBoxesLeft )
+{
+    Tim_Man_t * pManTime = (Tim_Man_t *)p->pManTime;
+    assert( pManTime != NULL );
+    assert( Vec_IntSize(vBoxesLeft) <= Tim_ManBoxNum(pManTime) );
+    return Tim_ManReduce( pManTime, vBoxesLeft );
+}
 
 /**Function*************************************************************
 
@@ -615,7 +638,7 @@ void * Gia_ManUpdateTimMan( Gia_Man_t * p, Vec_Int_t * vBoxPres )
 ***********************************************************************/
 Gia_Man_t * Gia_ManUpdateExtraAig( void * pTime, Gia_Man_t * p, Vec_Int_t * vBoxPres )
 {
-    Gia_Man_t * pNew = NULL;
+    Gia_Man_t * pNew;
     Tim_Man_t * pManTime = (Tim_Man_t *)pTime;
     Vec_Int_t * vOutPres = Vec_IntAlloc( 100 );
     int i, k, curPo = 0;
@@ -628,11 +651,32 @@ Gia_Man_t * Gia_ManUpdateExtraAig( void * pTime, Gia_Man_t * p, Vec_Int_t * vBox
         curPo += Tim_ManBoxOutputNum(pManTime, i);
     }
     assert( curPo == Gia_ManCoNum(p) );
-//    if ( Vec_IntSize(vOutPres) > 0 )
-        pNew = Gia_ManDupOutputVec( p, vOutPres );
+    pNew = Gia_ManDupOutputVec( p, vOutPres );
     Vec_IntFree( vOutPres );
     return pNew;
 }
+Gia_Man_t * Gia_ManUpdateExtraAig2( void * pTime, Gia_Man_t * p, Vec_Int_t * vBoxesLeft )
+{
+    Gia_Man_t * pNew;
+    Tim_Man_t * pManTime = (Tim_Man_t *)pTime;
+    int nRealPis = Tim_ManPiNum(pManTime);
+    Vec_Int_t * vOutsLeft;
+    int i, k, iBox, iOutFirst;
+    if ( Vec_IntSize(vBoxesLeft) == Tim_ManBoxNum(pManTime) )
+        return Gia_ManDup( p );
+    assert( Vec_IntSize(vBoxesLeft) < Tim_ManBoxNum(pManTime) );
+    assert( Gia_ManCoNum(p) == Tim_ManCiNum(pManTime) - nRealPis );
+    vOutsLeft = Vec_IntAlloc( 100 );
+    Vec_IntForEachEntry( vBoxesLeft, iBox, i )
+    {
+        iOutFirst = Tim_ManBoxOutputFirst(pManTime, iBox) - nRealPis;
+        for ( k = 0; k < Tim_ManBoxOutputNum(pManTime, iBox); k++ )
+            Vec_IntPush( vOutsLeft, iOutFirst + k );
+    }
+    pNew = Gia_ManDupSelectedOutputs( p, vOutsLeft );
+    Vec_IntFree( vOutsLeft );
+    return pNew;
+}
 
 /**Function*************************************************************
 
diff --git a/src/base/abc/abcDfs.c b/src/base/abc/abcDfs.c
index caeacb8e..4508f334 100644
--- a/src/base/abc/abcDfs.c
+++ b/src/base/abc/abcDfs.c
@@ -1460,8 +1460,6 @@ int Abc_NtkIsAcyclicWithBoxes_rec( Abc_Obj_t * pNode )
     Abc_Obj_t * pFanin;
     int fAcyclic, i;
     assert( !Abc_ObjIsNet(pNode) );
-    if ( Abc_ObjIsBo(pNode) )
-        pNode = Abc_ObjFanin0(pNode);
     if ( Abc_ObjIsPi(pNode) || Abc_ObjIsLatch(pNode) || Abc_ObjIsBlackbox(pNode) )
         return 1;
     assert( Abc_ObjIsNode(pNode) || Abc_ObjIsBox(pNode) );
@@ -1485,8 +1483,6 @@ int Abc_NtkIsAcyclicWithBoxes_rec( Abc_Obj_t * pNode )
         if ( Abc_ObjIsBox(pNode) )
             pFanin = Abc_ObjFanin0(pFanin);
         pFanin = Abc_ObjFanin0Ntk(pFanin);
-        // make sure there is no mixing of networks
-        assert( pFanin->pNtk == pNode->pNtk );
         if ( Abc_ObjIsBo(pFanin) )
             pFanin = Abc_ObjFanin0(pFanin);
         // check if the fanin is visited
@@ -1523,6 +1519,8 @@ int Abc_NtkIsAcyclicWithBoxes( Abc_Ntk_t * pNtk )
     Abc_NtkForEachPo( pNtk, pNode, i )
     {
         pNode = Abc_ObjFanin0Ntk(Abc_ObjFanin0(pNode));
+        if ( Abc_ObjIsBo(pNode) )
+            pNode = Abc_ObjFanin0(pNode);
         if ( Abc_NodeIsTravIdPrevious(pNode) )
             continue;
         // traverse the output logic cone
@@ -1537,6 +1535,8 @@ int Abc_NtkIsAcyclicWithBoxes( Abc_Ntk_t * pNtk )
         Abc_NtkForEachLatchInput( pNtk, pNode, i )
         {
             pNode = Abc_ObjFanin0Ntk(Abc_ObjFanin0(pNode));
+            if ( Abc_ObjIsBo(pNode) )
+                pNode = Abc_ObjFanin0(pNode);
             if ( Abc_NodeIsTravIdPrevious(pNode) )
                 continue;
             // traverse the output logic cone
diff --git a/src/base/abci/abc.c b/src/base/abci/abc.c
index e7bd2a6a..7b08c564 100644
--- a/src/base/abci/abc.c
+++ b/src/base/abci/abc.c
@@ -440,6 +440,7 @@ static int Abc_CommandAbc9Bmci               ( Abc_Frame_t * pAbc, int argc, cha
 static int Abc_CommandAbc9PoXsim             ( Abc_Frame_t * pAbc, int argc, char ** argv );
 static int Abc_CommandAbc9Demiter            ( Abc_Frame_t * pAbc, int argc, char ** argv );
 static int Abc_CommandAbc9Fadds              ( Abc_Frame_t * pAbc, int argc, char ** argv );
+static int Abc_CommandAbc9Mfs                ( Abc_Frame_t * pAbc, int argc, char ** argv );
 //static int Abc_CommandAbc9PoPart2            ( Abc_Frame_t * pAbc, int argc, char ** argv );
 //static int Abc_CommandAbc9CexCut             ( Abc_Frame_t * pAbc, int argc, char ** argv );
 //static int Abc_CommandAbc9CexMerge           ( Abc_Frame_t * pAbc, int argc, char ** argv );
@@ -1042,6 +1043,7 @@ void Abc_Init( Abc_Frame_t * pAbc )
     Cmd_CommandAdd( pAbc, "ABC9",         "&poxsim",       Abc_CommandAbc9PoXsim,       0 );
     Cmd_CommandAdd( pAbc, "ABC9",         "&demiter",      Abc_CommandAbc9Demiter,      0 );
     Cmd_CommandAdd( pAbc, "ABC9",         "&fadds",        Abc_CommandAbc9Fadds,        0 );
+    Cmd_CommandAdd( pAbc, "ABC9",         "&mfs",          Abc_CommandAbc9Mfs,          0 );
 //    Cmd_CommandAdd( pAbc, "ABC9",         "&popart2",      Abc_CommandAbc9PoPart2,      0 );
 //    Cmd_CommandAdd( pAbc, "ABC9",         "&cexcut",       Abc_CommandAbc9CexCut,       0 );
 //    Cmd_CommandAdd( pAbc, "ABC9",         "&cexmerge",     Abc_CommandAbc9CexMerge,     0 );
@@ -36629,6 +36631,162 @@ usage:
   Synopsis    []
 
   Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int Abc_CommandAbc9Mfs( Abc_Frame_t * pAbc, int argc, char ** argv )
+{
+    extern Gia_Man_t * Gia_ManPerformMfs( Gia_Man_t * p, Sfm_Par_t * pPars );
+    Gia_Man_t * pTemp; int c;
+    Sfm_Par_t Pars, * pPars = &Pars;
+    Sfm_ParSetDefault( pPars );
+    pPars->nTfoLevMax  =    5;
+    pPars->nDepthMax   =  100;
+    pPars->nWinSizeMax = 2000; 
+    Extra_UtilGetoptReset();
+    while ( ( c = Extra_UtilGetopt( argc, argv, "WFDMLCNdaevwh" ) ) != EOF )
+    {
+        switch ( c )
+        {
+        case 'W':
+            if ( globalUtilOptind >= argc )
+            {
+                Abc_Print( -1, "Command line switch \"-W\" should be followed by an integer.\n" );
+                goto usage;
+            }
+            pPars->nTfoLevMax = atoi(argv[globalUtilOptind]);
+            globalUtilOptind++;
+            if ( pPars->nTfoLevMax < 0 )
+                goto usage;
+            break;
+        case 'F':
+            if ( globalUtilOptind >= argc )
+            {
+                Abc_Print( -1, "Command line switch \"-F\" should be followed by an integer.\n" );
+                goto usage;
+            }
+            pPars->nFanoutMax = atoi(argv[globalUtilOptind]);
+            globalUtilOptind++;
+            if ( pPars->nFanoutMax < 0 )
+                goto usage;
+            break;
+        case 'D':
+            if ( globalUtilOptind >= argc )
+            {
+                Abc_Print( -1, "Command line switch \"-D\" should be followed by an integer.\n" );
+                goto usage;
+            }
+            pPars->nDepthMax = atoi(argv[globalUtilOptind]);
+            globalUtilOptind++;
+            if ( pPars->nDepthMax < 0 )
+                goto usage;
+            break;
+        case 'M':
+            if ( globalUtilOptind >= argc )
+            {
+                Abc_Print( -1, "Command line switch \"-M\" should be followed by an integer.\n" );
+                goto usage;
+            }
+            pPars->nWinSizeMax = atoi(argv[globalUtilOptind]);
+            globalUtilOptind++;
+            if ( pPars->nWinSizeMax < 0 )
+                goto usage;
+            break;
+        case 'L':
+            if ( globalUtilOptind >= argc )
+            {
+                Abc_Print( -1, "Command line switch \"-L\" should be followed by an integer.\n" );
+                goto usage;
+            }
+            pPars->nGrowthLevel = atoi(argv[globalUtilOptind]);
+            globalUtilOptind++;
+            if ( pPars->nGrowthLevel < 0 || pPars->nGrowthLevel > ABC_INFINITY )
+                goto usage;
+            break;
+        case 'C':
+            if ( globalUtilOptind >= argc )
+            {
+                Abc_Print( -1, "Command line switch \"-C\" should be followed by an integer.\n" );
+                goto usage;
+            }
+            pPars->nBTLimit = atoi(argv[globalUtilOptind]);
+            globalUtilOptind++;
+            if ( pPars->nBTLimit < 0 )
+                goto usage;
+            break;
+        case 'N':
+            if ( globalUtilOptind >= argc )
+            {
+                Abc_Print( -1, "Command line switch \"-N\" should be followed by an integer.\n" );
+                goto usage;
+            }
+            pPars->nNodesMax = atoi(argv[globalUtilOptind]);
+            globalUtilOptind++;
+            if ( pPars->nNodesMax < 0 )
+                goto usage;
+            break;
+        case 'd':
+            pPars->fRrOnly ^= 1;
+            break;
+        case 'a':
+            pPars->fArea ^= 1;
+            break;
+        case 'e':
+            pPars->fMoreEffort ^= 1;
+            break;
+        case 'v':
+            pPars->fVerbose ^= 1;
+            break;
+        case 'w':
+            pPars->fVeryVerbose ^= 1;
+            break;
+        case 'h':
+            goto usage;
+        default:
+            goto usage;
+        }
+    }
+    if ( pAbc->pGia == NULL )
+    {
+        Abc_Print( -1, "Abc_CommandAbc9Mfs(): There is no AIG.\n" );
+        return 0;
+    }
+    if ( !Gia_ManHasMapping(pAbc->pGia) )
+    {
+        Abc_Print( -1, "Abc_CommandAbc9Mfs(): The current AIG has no mapping.\n" );
+        return 0;
+    }
+    pTemp = Gia_ManPerformMfs( pAbc->pGia, pPars );
+    Abc_FrameUpdateGia( pAbc, pTemp );
+    return 0;
+
+usage:
+    Abc_Print( -2, "usage: &mfs [-WFDMLCN <num>] [-daevwh]\n" );
+    Abc_Print( -2, "\t           performs don't-care-based optimization of logic networks\n" );
+    Abc_Print( -2, "\t-W <num> : the number of levels in the TFO cone (0 <= num) [default = %d]\n",             pPars->nTfoLevMax );
+    Abc_Print( -2, "\t-F <num> : the max number of fanouts to skip (1 <= num) [default = %d]\n",                pPars->nFanoutMax );
+    Abc_Print( -2, "\t-D <num> : the max depth nodes to try (0 = no limit) [default = %d]\n",                   pPars->nDepthMax );
+    Abc_Print( -2, "\t-M <num> : the max node count of windows to consider (0 = no limit) [default = %d]\n",    pPars->nWinSizeMax );
+    Abc_Print( -2, "\t-L <num> : the max increase in node level after resynthesis (0 <= num) [default = %d]\n", pPars->nGrowthLevel );
+    Abc_Print( -2, "\t-C <num> : the max number of conflicts in one SAT run (0 = no limit) [default = %d]\n",   pPars->nBTLimit );
+    Abc_Print( -2, "\t-N <num> : the max number of nodes to try (0 = all) [default = %d]\n",                    pPars->nNodesMax );
+    Abc_Print( -2, "\t-d       : toggle performing redundancy removal [default = %s]\n",                        pPars->fRrOnly? "yes": "no" );
+    Abc_Print( -2, "\t-a       : toggle minimizing area or area+edges [default = %s]\n",                        pPars->fArea? "area": "area+edges" );
+    Abc_Print( -2, "\t-e       : toggle high-effort resubstitution [default = %s]\n",                           pPars->fMoreEffort? "yes": "no" );
+    Abc_Print( -2, "\t-v       : toggle printing optimization summary [default = %s]\n",                        pPars->fVerbose? "yes": "no" );
+    Abc_Print( -2, "\t-w       : toggle printing detailed stats for each node [default = %s]\n",                pPars->fVeryVerbose? "yes": "no" );
+    Abc_Print( -2, "\t-h       : print the command usage\n");
+    return 1;
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
 
   SideEffects []
 
diff --git a/src/base/abci/abcMfs.c b/src/base/abci/abcMfs.c
index e6d07993..aab18ed0 100644
--- a/src/base/abci/abcMfs.c
+++ b/src/base/abci/abcMfs.c
@@ -270,7 +270,6 @@ int Abc_NtkPerformMfs( Abc_Ntk_t * pNtk, Sfm_Par_t * pPars )
     p = Abc_NtkExtractMfs( pNtk, pPars->nFirstFixed );
     // perform optimization
     nNodes = Sfm_NtkPerform( p, pPars );
-    // call the fast extract procedure
     if ( nNodes == 0 )
     {
 //        Abc_Print( 1, "The network is not changed by \"mfs\".\n" );
@@ -451,7 +450,6 @@ int Abc_NtkMfsAfterICheck( Abc_Ntk_t * p, int nFrames, int nFramesAdd, Vec_Int_t
     pp = Abc_NtkExtractMfs2( pNtk, iPivot );
     // perform optimization
     nNodes = Sfm_NtkPerform( pp, pPars );
-    // call the fast extract procedure
     if ( nNodes == 0 )
     {
 //        Abc_Print( 1, "The network is not changed by \"mfs\".\n" );
diff --git a/src/misc/tim/tim.h b/src/misc/tim/tim.h
index ba2b1bdb..df69ae36 100644
--- a/src/misc/tim/tim.h
+++ b/src/misc/tim/tim.h
@@ -130,6 +130,7 @@ extern Tim_Man_t *     Tim_ManLoad( Vec_Str_t * p, int fHieOnly );
 extern Tim_Man_t *     Tim_ManStart( int nCis, int nCos );
 extern Tim_Man_t *     Tim_ManDup( Tim_Man_t * p, int fUnitDelay );
 extern Tim_Man_t *     Tim_ManTrim( Tim_Man_t * p, Vec_Int_t * vBoxPres );
+extern Tim_Man_t *     Tim_ManReduce( Tim_Man_t * p, Vec_Int_t * vBoxesLeft );
 extern Vec_Int_t *     Tim_ManAlignTwo( Tim_Man_t * pSpec, Tim_Man_t * pImpl );
 extern void            Tim_ManCreate( Tim_Man_t * p, void * pLib, Vec_Flt_t * vInArrs, Vec_Flt_t * vOutReqs );
 extern float *         Tim_ManGetArrTimes( Tim_Man_t * p );
diff --git a/src/misc/tim/timMan.c b/src/misc/tim/timMan.c
index c3caf4dc..8fcc8eaf 100644
--- a/src/misc/tim/timMan.c
+++ b/src/misc/tim/timMan.c
@@ -239,6 +239,93 @@ Tim_Man_t * Tim_ManTrim( Tim_Man_t * p, Vec_Int_t * vBoxPres )
 
 /**Function*************************************************************
 
+  Synopsis    [Trims the timing manager.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+Tim_Man_t * Tim_ManReduce( Tim_Man_t * p, Vec_Int_t * vBoxesLeft )
+{
+    Tim_Man_t * pNew;
+    Tim_Box_t * pBox;
+    Tim_Obj_t * pObj;
+    float * pDelayTable, * pDelayTableNew;
+    int i, k, iBox, nNewCis, nNewCos, nInputs, nOutputs;
+    if ( Vec_IntSize(vBoxesLeft) == Tim_ManBoxNum(p) )
+        return Tim_ManDup( p, 0 );
+    assert( Vec_IntSize(vBoxesLeft) < Tim_ManBoxNum(p) );
+    // count the number of CIs and COs in the trimmed manager
+    nNewCis = Tim_ManPiNum(p);
+    nNewCos = Tim_ManPoNum(p);
+    Vec_IntForEachEntry( vBoxesLeft, iBox, i )
+    {
+        pBox = Tim_ManBox( p, iBox );
+        nNewCis += pBox->nOutputs;
+        nNewCos += pBox->nInputs;
+    }
+    assert( nNewCis < Tim_ManCiNum(p) );
+    assert( nNewCos < Tim_ManCoNum(p) );
+    // clear traversal IDs
+    Tim_ManForEachCi( p, pObj, i ) 
+        pObj->TravId = 0;          
+    Tim_ManForEachCo( p, pObj, i ) 
+        pObj->TravId = 0;          
+    // create new manager
+    pNew = Tim_ManStart( nNewCis, nNewCos );
+    // copy box connectivity information
+    memcpy( pNew->pCis, p->pCis, sizeof(Tim_Obj_t) * Tim_ManPiNum(p) );
+    memcpy( pNew->pCos + nNewCos - Tim_ManPoNum(p), 
+            p->pCos + Tim_ManCoNum(p) - Tim_ManPoNum(p), 
+            sizeof(Tim_Obj_t) * Tim_ManPoNum(p) );
+    // duplicate delay tables
+    if ( Tim_ManDelayTableNum(p) > 0 )
+    {
+        pNew->vDelayTables = Vec_PtrStart( Vec_PtrSize(p->vDelayTables) );
+        Tim_ManForEachTable( p, pDelayTable, i )
+        {
+            if ( pDelayTable == NULL )
+                continue;
+            assert( i == (int)pDelayTable[0] );
+            nInputs   = (int)pDelayTable[1];
+            nOutputs  = (int)pDelayTable[2];
+            pDelayTableNew = ABC_ALLOC( float, 3 + nInputs * nOutputs );
+            pDelayTableNew[0] = (int)pDelayTable[0];
+            pDelayTableNew[1] = (int)pDelayTable[1];
+            pDelayTableNew[2] = (int)pDelayTable[2];
+            for ( k = 0; k < nInputs * nOutputs; k++ )
+                pDelayTableNew[3+k] = pDelayTable[3+k];
+//            assert( (int)pDelayTableNew[0] == Vec_PtrSize(pNew->vDelayTables) );
+            assert( Vec_PtrEntry(pNew->vDelayTables, i) == NULL );
+            Vec_PtrWriteEntry( pNew->vDelayTables, i, pDelayTableNew );
+        }
+    }
+    // duplicate boxes
+    if ( Tim_ManBoxNum(p) > 0 )
+    {
+        int curPi = Tim_ManPiNum(p);
+        int curPo = 0;
+        pNew->vBoxes = Vec_PtrAlloc( Tim_ManBoxNum(p) );
+        Vec_IntForEachEntry( vBoxesLeft, iBox, i )
+        {
+            pBox = Tim_ManBox( p, iBox );
+            Tim_ManCreateBox( pNew, curPo, pBox->nInputs, curPi, pBox->nOutputs, pBox->iDelayTable );
+            Tim_ManBoxSetCopy( pNew, Tim_ManBoxNum(pNew) - 1, iBox );
+            curPi += pBox->nOutputs;
+            curPo += pBox->nInputs;
+        }
+        curPo += Tim_ManPoNum(p);
+        assert( curPi == Tim_ManCiNum(pNew) );
+        assert( curPo == Tim_ManCoNum(pNew) );
+    }
+    return pNew;
+}
+
+/**Function*************************************************************
+
   Synopsis    [Aligns two sets of boxes using the copy field.]
 
   Description []
diff --git a/src/opt/sfm/sfm.h b/src/opt/sfm/sfm.h
index c8a30030..1d97cd8b 100644
--- a/src/opt/sfm/sfm.h
+++ b/src/opt/sfm/sfm.h
@@ -77,7 +77,7 @@ extern word *       Sfm_NodeReadTruth( Sfm_Ntk_t * p, int i );
 extern int          Sfm_NodeReadFixed( Sfm_Ntk_t * p, int i );
 extern int          Sfm_NodeReadUsed( Sfm_Ntk_t * p, int i );
 /*=== sfmWin.c ==========================================================*/
-extern Vec_Int_t *  Sfm_NtkDfs( Sfm_Ntk_t * p );
+extern Vec_Int_t *  Sfm_NtkDfs( Sfm_Ntk_t * p, Vec_Wec_t * vGroups, Vec_Int_t * vGroupMap, Vec_Int_t * vBoxesLeft );
 
 
 ABC_NAMESPACE_HEADER_END
diff --git a/src/opt/sfm/sfmNtk.c b/src/opt/sfm/sfmNtk.c
index fd04e432..1ded0ede 100644
--- a/src/opt/sfm/sfmNtk.c
+++ b/src/opt/sfm/sfmNtk.c
@@ -54,7 +54,8 @@ void Sfm_CheckConsistency( Vec_Wec_t * vFanins, int nPis, int nPos, Vec_Str_t *
             assert( Vec_IntSize(vArray) == 0 && Vec_StrEntry(vFixed, i) == (char)0 );
         // nodes are in a topo order; POs cannot be fanins
         Vec_IntForEachEntry( vArray, Fanin, k )
-            assert( Fanin < i && Fanin + nPos < Vec_WecSize(vFanins) );
+//            assert( Fanin < i && Fanin + nPos < Vec_WecSize(vFanins) );
+            assert( Fanin + nPos < Vec_WecSize(vFanins) );
         // POs have one fanout
         if ( i + nPos >= Vec_WecSize(vFanins) )
             assert( Vec_IntSize(vArray) == 1 && Vec_StrEntry(vFixed, i) == (char)0 );
diff --git a/src/opt/sfm/sfmWin.c b/src/opt/sfm/sfmWin.c
index 9f91c936..6eab478e 100644
--- a/src/opt/sfm/sfmWin.c
+++ b/src/opt/sfm/sfmWin.c
@@ -125,33 +125,53 @@ static inline int   Sfm_ObjIsTravIdCurrent2( Sfm_Ntk_t * p, int Id )   { return
 
   Synopsis    [Collects used internal nodes in a topological order.]
 
-  Description []
+  Description [Additionally considers objects in groups as a single object
+  and collects them in a topological order together as single entity.]
                
   SideEffects []
 
   SeeAlso     []
 
 ***********************************************************************/
-void Sfm_NtkDfs_rec( Sfm_Ntk_t * p, int iNode, Vec_Int_t * vNodes )
+void Sfm_NtkDfs_rec( Sfm_Ntk_t * p, int iNode, Vec_Int_t * vNodes, Vec_Wec_t * vGroups, Vec_Int_t * vGroupMap, Vec_Int_t * vBoxesLeft )
 {
     int i, iFanin;
     if ( Sfm_ObjIsPi(p, iNode) )
         return;
     if ( Sfm_ObjIsTravIdCurrent(p, iNode) )
         return;
-    Sfm_ObjSetTravIdCurrent(p, iNode);
-    Sfm_ObjForEachFanin( p, iNode, iFanin, i )
-        Sfm_NtkDfs_rec( p, iFanin, vNodes );
-    Vec_IntPush( vNodes, iNode );
+    if ( Vec_IntEntry(vGroupMap, iNode) >= 0 )
+    {
+        int k, iGroup = Abc_Lit2Var( Vec_IntEntry(vGroupMap, iNode) );
+        Vec_Int_t * vGroup = Vec_WecEntry( vGroups, iGroup );
+        Vec_IntForEachEntry( vGroup, iNode, i )
+            assert( Sfm_ObjIsNode(p, iNode) );
+        Vec_IntForEachEntry( vGroup, iNode, i )
+            Sfm_ObjSetTravIdCurrent( p, iNode );
+        Vec_IntForEachEntry( vGroup, iNode, i )
+            Sfm_ObjForEachFanin( p, iNode, iFanin, k )
+                Sfm_NtkDfs_rec( p, iFanin, vNodes, vGroups, vGroupMap, vBoxesLeft );
+        Vec_IntForEachEntry( vGroup, iNode, i )
+            Vec_IntPush( vNodes, iNode );
+        Vec_IntPush( vBoxesLeft, iGroup );
+    }
+    else
+    {
+        Sfm_ObjSetTravIdCurrent(p, iNode);
+        Sfm_ObjForEachFanin( p, iNode, iFanin, i )
+            Sfm_NtkDfs_rec( p, iFanin, vNodes, vGroups, vGroupMap, vBoxesLeft );
+        Vec_IntPush( vNodes, iNode );
+    }
 }
-Vec_Int_t * Sfm_NtkDfs( Sfm_Ntk_t * p )
+Vec_Int_t * Sfm_NtkDfs( Sfm_Ntk_t * p, Vec_Wec_t * vGroups, Vec_Int_t * vGroupMap, Vec_Int_t * vBoxesLeft )
 {
     Vec_Int_t * vNodes;
     int i;
+    Vec_IntClear( vBoxesLeft );
     vNodes = Vec_IntAlloc( p->nObjs );
     Sfm_NtkIncrementTravId( p );
     Sfm_NtkForEachPo( p, i )
-        Sfm_NtkDfs_rec( p, Sfm_ObjFanin(p, i, 0), vNodes );
+        Sfm_NtkDfs_rec( p, Sfm_ObjFanin(p, i, 0), vNodes, vGroups, vGroupMap, vBoxesLeft );
     return vNodes;
 }