Improvements and tuning of CBA with buffering/sizing.

13 files changed, 142 insertions, 85 deletions

diff --git a/src/base/abc/abc.h b/src/base/abc/abc.h
index c23a711a..bf84226b 100644
--- a/src/base/abc/abc.h
+++ b/src/base/abc/abc.h
@@ -358,7 +358,7 @@ static inline int         Abc_ObjIsLatch( Abc_Obj_t * pObj )         { return pO
 static inline int         Abc_ObjIsBox( Abc_Obj_t * pObj )           { return pObj->Type == ABC_OBJ_LATCH || pObj->Type == ABC_OBJ_WHITEBOX || pObj->Type == ABC_OBJ_BLACKBOX; }
 static inline int         Abc_ObjIsWhitebox( Abc_Obj_t * pObj )      { return pObj->Type == ABC_OBJ_WHITEBOX;}
 static inline int         Abc_ObjIsBlackbox( Abc_Obj_t * pObj )      { return pObj->Type == ABC_OBJ_BLACKBOX;}
-static inline int         Abc_ObjIsBarBuf( Abc_Obj_t * pObj )        { return Abc_NtkIsLogic(pObj->pNtk) && Abc_ObjIsNode(pObj) && Vec_IntSize(&pObj->vFanins) == 1 && pObj->pData == NULL;  }
+static inline int         Abc_ObjIsBarBuf( Abc_Obj_t * pObj )        { return Abc_NtkHasMapping(pObj->pNtk) && Abc_ObjIsNode(pObj) && Vec_IntSize(&pObj->vFanins) == 1 && pObj->pData == NULL;  }
 static inline void        Abc_ObjBlackboxToWhitebox( Abc_Obj_t * pObj ) { assert( Abc_ObjIsBlackbox(pObj) ); pObj->Type = ABC_OBJ_WHITEBOX; pObj->pNtk->nObjCounts[ABC_OBJ_BLACKBOX]--; pObj->pNtk->nObjCounts[ABC_OBJ_WHITEBOX]++; }
 
 // working with fanin/fanout edges
diff --git a/src/base/abc/abcDfs.c b/src/base/abc/abcDfs.c
index 9dd2b4bf..811a6929 100644
--- a/src/base/abc/abcDfs.c
+++ b/src/base/abc/abcDfs.c
@@ -87,14 +87,17 @@ Vec_Ptr_t * Abc_NtkDfs( Abc_Ntk_t * pNtk, int fCollectAll )
     Abc_NtkIncrementTravId( pNtk );
     // start the array of nodes
     vNodes = Vec_PtrAlloc( 100 );
-    Abc_NtkForEachObj( pNtk, pObj, i )
+    if ( pNtk->nBarBufs2 > 0 )
+    Abc_NtkForEachBarBuf( pNtk, pObj, i )
+    {
+        Abc_NodeSetTravIdCurrent( pObj );
+        Abc_NtkDfs_rec( Abc_ObjFanin0Ntk(Abc_ObjFanin0(pObj)), vNodes );
+        Vec_PtrPush( vNodes, pObj );
+    }
+    Abc_NtkForEachCo( pNtk, pObj, i )
     {
-        if ( !Abc_ObjIsCo(pObj) && !Abc_ObjIsBarBuf(pObj) )
-            continue;
         Abc_NodeSetTravIdCurrent( pObj );
         Abc_NtkDfs_rec( Abc_ObjFanin0Ntk(Abc_ObjFanin0(pObj)), vNodes );
-        if ( Abc_ObjIsBarBuf(pObj) )
-            Vec_PtrPush( vNodes, pObj );
     }
     // collect dangling nodes if asked to
     if ( fCollectAll )
diff --git a/src/base/abc/abcFunc.c b/src/base/abc/abcFunc.c
index 782091d7..6e9e3d09 100644
--- a/src/base/abc/abcFunc.c
+++ b/src/base/abc/abcFunc.c
@@ -1081,7 +1081,6 @@ int Abc_NtkMapToSop( Abc_Ntk_t * pNtk )
     // update the functionality manager
     assert( pNtk->pManFunc == Abc_FrameReadLibGen() );
     pNtk->pManFunc = Mem_FlexStart();
-    pNtk->ntkFunc  = ABC_FUNC_SOP;
     // update the nodes
     Abc_NtkForEachNode( pNtk, pNode, i )
     {
@@ -1091,6 +1090,7 @@ int Abc_NtkMapToSop( Abc_Ntk_t * pNtk )
         assert( Abc_SopGetVarNum(pSop) == Abc_ObjFaninNum(pNode) );
         pNode->pData = Abc_SopRegister( (Mem_Flex_t *)pNtk->pManFunc, pSop );
     }
+    pNtk->ntkFunc  = ABC_FUNC_SOP;
     return 1;
 }
 
diff --git a/src/base/abc/abcObj.c b/src/base/abc/abcObj.c
index 94a5f0bb..91d89026 100644
--- a/src/base/abc/abcObj.c
+++ b/src/base/abc/abcObj.c
@@ -377,7 +377,7 @@ Abc_Obj_t * Abc_NtkDupObj( Abc_Ntk_t * pNtkNew, Abc_Obj_t * pObj, int fCopyName
             else if ( Abc_NtkHasAig(pNtkNew) )
                 pObjNew->pData = Hop_Transfer((Hop_Man_t *)pObj->pNtk->pManFunc, (Hop_Man_t *)pNtkNew->pManFunc, (Hop_Obj_t *)pObj->pData, Abc_ObjFaninNum(pObj));
             else if ( Abc_NtkHasMapping(pNtkNew) )
-                pObjNew->pData = pObj->pData;
+                pObjNew->pData = pObj->pData, pNtkNew->nBarBufs2 += !pObj->pData;
             else assert( 0 );
         }
     }
diff --git a/src/base/abci/abcPrint.c b/src/base/abci/abcPrint.c
index 02c06e65..361f1e99 100644
--- a/src/base/abci/abcPrint.c
+++ b/src/base/abci/abcPrint.c
@@ -1073,7 +1073,7 @@ void Abc_NtkPrintGates( Abc_Ntk_t * pNtk, int fUseLibrary )
 
         // count the gates by name
         CounterTotal = 0;
-        Abc_NtkForEachNode( pNtk, pObj, i )
+        Abc_NtkForEachNodeNotBarBuf( pNtk, pObj, i )
         {
             if ( i == 0 ) continue;
             Mio_GateSetValue( (Mio_Gate_t *)pObj->pData, 1 + Mio_GateReadValue((Mio_Gate_t *)pObj->pData) );
@@ -1128,7 +1128,7 @@ void Abc_NtkPrintGates( Abc_Ntk_t * pNtk, int fUseLibrary )
 
     // get hold of the SOP of the node
     CountConst = CountBuf = CountInv = CountAnd = CountOr = CountOther = CounterTotal = 0;
-    Abc_NtkForEachNode( pNtk, pObj, i )
+    Abc_NtkForEachNodeNotBarBuf( pNtk, pObj, i )
     {
         if ( i == 0 ) continue;
         if ( Abc_NtkHasMapping(pNtk) )
diff --git a/src/base/cba/cba.h b/src/base/cba/cba.h
index f1b94390..2ac3ed35 100644
--- a/src/base/cba/cba.h
+++ b/src/base/cba/cba.h
@@ -157,10 +157,10 @@ struct Cba_Man_t_
     int          nNtks;    // number of current networks
     Cba_Ntk_t *  pNtks;    // networks
     // user data
-    Vec_Int_t *  vBuf2RootNtk;
-    Vec_Int_t *  vBuf2RootObj;
-    Vec_Int_t *  vBuf2LeafNtk;
-    Vec_Int_t *  vBuf2LeafObj;
+    Vec_Int_t    vBuf2RootNtk;
+    Vec_Int_t    vBuf2RootObj;
+    Vec_Int_t    vBuf2LeafNtk;
+    Vec_Int_t    vBuf2LeafObj;
     void *       pMioLib;
     void **      ppGraphs;
     int          ElemGates[4];
@@ -574,10 +574,10 @@ static inline void Cba_ManFree( Cba_Man_t * p )
     Cba_Ntk_t * pNtk; int i;
     Cba_ManForEachNtk( p, pNtk, i )
         Cba_NtkFree( pNtk );
-    Vec_IntFreeP( &p->vBuf2LeafNtk );
-    Vec_IntFreeP( &p->vBuf2LeafObj );
-    Vec_IntFreeP( &p->vBuf2RootNtk );
-    Vec_IntFreeP( &p->vBuf2RootObj );
+    Vec_IntErase( &p->vBuf2LeafNtk );
+    Vec_IntErase( &p->vBuf2LeafObj );
+    Vec_IntErase( &p->vBuf2RootNtk );
+    Vec_IntErase( &p->vBuf2RootObj );
     Abc_NamDeref( p->pStrs );
     Abc_NamDeref( p->pMods );
     ABC_FREE( p->pName );
diff --git a/src/base/cba/cbaBlast.c b/src/base/cba/cbaBlast.c
index 2f955241..aff8799a 100644
--- a/src/base/cba/cbaBlast.c
+++ b/src/base/cba/cbaBlast.c
@@ -90,12 +90,12 @@ int Cba_ManAddBarbuf( Gia_Man_t * pNew, int iRes, Cba_Man_t * p, int iLNtk, int
         return iRes;
     assert( iRes > 0 );
     if ( vMap && Abc_Lit2Var(iRes) < Vec_IntSize(vMap) && (iIdLit = Vec_IntEntry(vMap, Abc_Lit2Var(iRes))) >= 0 && 
-        Vec_IntEntry(p->vBuf2LeafNtk, Abc_Lit2Var(iIdLit)) == iLNtk && Vec_IntEntry(p->vBuf2RootNtk, Abc_Lit2Var(iIdLit)) == iRNtk )
+        Vec_IntEntry(&p->vBuf2LeafNtk, Abc_Lit2Var(iIdLit)) == iLNtk && Vec_IntEntry(&p->vBuf2RootNtk, Abc_Lit2Var(iIdLit)) == iRNtk )
         return Abc_LitNotCond( Vec_IntEntry(pNew->vBarBufs, Abc_Lit2Var(iIdLit)), Abc_LitIsCompl(iRes) ^ Abc_LitIsCompl(iIdLit) );
-    Vec_IntPush( p->vBuf2LeafNtk, iLNtk );
-    Vec_IntPush( p->vBuf2LeafObj, iLObj );
-    Vec_IntPush( p->vBuf2RootNtk, iRNtk );
-    Vec_IntPush( p->vBuf2RootObj, iRObj );
+    Vec_IntPush( &p->vBuf2LeafNtk, iLNtk );
+    Vec_IntPush( &p->vBuf2LeafObj, iLObj );
+    Vec_IntPush( &p->vBuf2RootNtk, iRNtk );
+    Vec_IntPush( &p->vBuf2RootObj, iRObj );
     iBufLit = Gia_ManAppendBuf( pNew, iRes );
     if ( vMap )
     {
@@ -196,14 +196,10 @@ Gia_Man_t * Cba_ManExtract( Cba_Man_t * p, int fBuffers, int fVerbose )
     Vec_Int_t * vMap = NULL;
     int i, iObj;
 
-    Vec_IntFreeP( &p->vBuf2LeafNtk );
-    Vec_IntFreeP( &p->vBuf2LeafObj );
-    Vec_IntFreeP( &p->vBuf2RootNtk );
-    Vec_IntFreeP( &p->vBuf2RootObj );
-    p->vBuf2LeafNtk = Vec_IntAlloc( 1000 );
-    p->vBuf2LeafObj = Vec_IntAlloc( 1000 );
-    p->vBuf2RootNtk = Vec_IntAlloc( 1000 );
-    p->vBuf2RootObj = Vec_IntAlloc( 1000 );
+    Vec_IntClear( &p->vBuf2LeafNtk );
+    Vec_IntClear( &p->vBuf2LeafObj );
+    Vec_IntClear( &p->vBuf2RootNtk );
+    Vec_IntClear( &p->vBuf2RootObj );
 
     Cba_ManForEachNtk( p, pNtk, i )
         Cba_NtkStartCopies(pNtk);
@@ -231,7 +227,7 @@ Gia_Man_t * Cba_ManExtract( Cba_Man_t * p, int fBuffers, int fVerbose )
     // primary outputs
     Cba_NtkForEachPo( pRoot, iObj, i )
         Gia_ManAppendCo( pNew, Cba_ObjCopy(pRoot, iObj) );
-    assert( Vec_IntSize(p->vBuf2LeafNtk) == pNew->nBufs );
+    assert( Vec_IntSize(&p->vBuf2LeafNtk) == pNew->nBufs );
 
     // cleanup
     pNew = Gia_ManCleanup( pTemp = pNew );
@@ -254,14 +250,14 @@ Gia_Man_t * Cba_ManExtract( Cba_Man_t * p, int fBuffers, int fVerbose )
 void Cba_ManMarkNodesGia( Cba_Man_t * p, Gia_Man_t * pGia )
 {
     Gia_Obj_t * pObj; int i, Count = 0;
-    assert( Vec_IntSize(p->vBuf2LeafNtk) == Gia_ManBufNum(pGia) );
+    assert( Vec_IntSize(&p->vBuf2LeafNtk) == Gia_ManBufNum(pGia) );
     Gia_ManConst0(pGia)->Value = 0;
     Gia_ManForEachPi( pGia, pObj, i )
         pObj->Value = 0;
     Gia_ManForEachAnd( pGia, pObj, i )
     {
         if ( Gia_ObjIsBuf(pObj) )
-            pObj->Value = Vec_IntEntry( p->vBuf2LeafNtk, Count++ );
+            pObj->Value = Vec_IntEntry( &p->vBuf2LeafNtk, Count++ );
         else
         {
             pObj->Value = Gia_ObjFanin0(pObj)->Value;
@@ -278,21 +274,21 @@ void Cba_ManMarkNodesGia( Cba_Man_t * p, Gia_Man_t * pGia )
 void Cba_ManRemapBarbufs( Cba_Man_t * pNew, Cba_Man_t * p )
 {
     Cba_Ntk_t * pNtk;  int Entry, i;
-    assert( p->vBuf2RootNtk != NULL );
-    assert( pNew->vBuf2RootNtk == NULL );
-    pNew->vBuf2RootNtk = Vec_IntDup( p->vBuf2RootNtk );
-    pNew->vBuf2RootObj = Vec_IntDup( p->vBuf2RootObj );
-    pNew->vBuf2LeafNtk = Vec_IntDup( p->vBuf2LeafNtk );
-    pNew->vBuf2LeafObj = Vec_IntDup( p->vBuf2LeafObj );
-    Vec_IntForEachEntry( p->vBuf2LeafObj, Entry, i )
+    assert( Vec_IntSize(&p->vBuf2RootNtk) );
+    assert( !Vec_IntSize(&pNew->vBuf2RootNtk) );
+    Vec_IntAppend( &pNew->vBuf2RootNtk, &p->vBuf2RootNtk );
+    Vec_IntAppend( &pNew->vBuf2RootObj, &p->vBuf2RootObj );
+    Vec_IntAppend( &pNew->vBuf2LeafNtk, &p->vBuf2LeafNtk );
+    Vec_IntAppend( &pNew->vBuf2LeafObj, &p->vBuf2LeafObj );
+    Vec_IntForEachEntry( &p->vBuf2LeafObj, Entry, i )
     {
-        pNtk = Cba_ManNtk( p, Vec_IntEntry(p->vBuf2LeafNtk, i) );
-        Vec_IntWriteEntry( pNew->vBuf2LeafObj, i, Cba_ObjCopy(pNtk, Entry) );
+        pNtk = Cba_ManNtk( p, Vec_IntEntry(&p->vBuf2LeafNtk, i) );
+        Vec_IntWriteEntry( &pNew->vBuf2LeafObj, i, Cba_ObjCopy(pNtk, Entry) );
     }
-    Vec_IntForEachEntry( p->vBuf2RootObj, Entry, i )
+    Vec_IntForEachEntry( &p->vBuf2RootObj, Entry, i )
     {
-        pNtk = Cba_ManNtk( p, Vec_IntEntry(p->vBuf2RootNtk, i) );
-        Vec_IntWriteEntry( pNew->vBuf2RootObj, i, Cba_ObjCopy(pNtk, Entry) );
+        pNtk = Cba_ManNtk( p, Vec_IntEntry(&p->vBuf2RootNtk, i) );
+        Vec_IntWriteEntry( &pNew->vBuf2RootObj, i, Cba_ObjCopy(pNtk, Entry) );
     }
 }
 void Cba_NtkCreateAndConnectBuffer( Gia_Man_t * pGia, Gia_Obj_t * pObj, Cba_Ntk_t * p, int iTerm )
@@ -326,13 +322,13 @@ void Cba_NtkInsertGia( Cba_Man_t * p, Gia_Man_t * pGia )
     {
         if ( Gia_ObjIsBuf(pObj) )
         {
-            pNtk = Cba_ManNtk( p, Vec_IntEntry(p->vBuf2RootNtk, Count) );
-            iTerm = Vec_IntEntry( p->vBuf2RootObj, Count );
+            pNtk = Cba_ManNtk( p, Vec_IntEntry(&p->vBuf2RootNtk, Count) );
+            iTerm = Vec_IntEntry( &p->vBuf2RootObj, Count );
             assert( Cba_ObjIsCo(pNtk, iTerm) );
             if ( Cba_ObjFanin(pNtk, iTerm) == -1 ) // not a feedthrough
                 Cba_NtkCreateAndConnectBuffer( pGia, pObj, pNtk, iTerm );
             // prepare leaf
-            pObj->Value = Vec_IntEntry( p->vBuf2LeafObj, Count++ );
+            pObj->Value = Vec_IntEntry( &p->vBuf2LeafObj, Count++ );
         }
         else
         {
@@ -424,13 +420,13 @@ static inline int Abc_NodeIsSeriousGate( Abc_Obj_t * p )
 void Cba_ManMarkNodesAbc( Cba_Man_t * p, Abc_Ntk_t * pNtk )
 {
     Abc_Obj_t * pObj, * pFanin; int i, k, Count = 0;
-    assert( Vec_IntSize(p->vBuf2LeafNtk) == pNtk->nBarBufs2 );
+    assert( Vec_IntSize(&p->vBuf2LeafNtk) == pNtk->nBarBufs2 );
     Abc_NtkForEachPi( pNtk, pObj, i )
         pObj->iTemp = 0;
     Abc_NtkForEachNode( pNtk, pObj, i )
     {
         if ( Abc_ObjIsBarBuf(pObj) )
-            pObj->iTemp = Vec_IntEntry( p->vBuf2LeafNtk, Count++ );
+            pObj->iTemp = Vec_IntEntry( &p->vBuf2LeafNtk, Count++ );
         else if ( Abc_NodeIsSeriousGate(pObj) )
         {
             pObj->iTemp = Abc_ObjFanin0(pObj)->iTemp;
@@ -505,13 +501,13 @@ void Cba_NtkInsertNtk( Cba_Man_t * p, Abc_Ntk_t * pNtk )
     {
         if ( Abc_ObjIsBarBuf(pObj) )
         {
-            pCbaNtk = Cba_ManNtk( p, Vec_IntEntry(p->vBuf2RootNtk, Count) );
-            iTerm = Vec_IntEntry( p->vBuf2RootObj, Count );
+            pCbaNtk = Cba_ManNtk( p, Vec_IntEntry(&p->vBuf2RootNtk, Count) );
+            iTerm = Vec_IntEntry( &p->vBuf2RootObj, Count );
             assert( Cba_ObjIsCo(pCbaNtk, iTerm) );
             if ( Cba_ObjFanin(pCbaNtk, iTerm) == -1 ) // not a feedthrough
                 Cba_NtkCreateOrConnectFanin( Abc_ObjFanin0(pObj), pCbaNtk, iTerm );
             // prepare leaf
-            pObj->iTemp = Vec_IntEntry( p->vBuf2LeafObj, Count++ );
+            pObj->iTemp = Vec_IntEntry( &p->vBuf2LeafObj, Count++ );
         }
         else if ( Abc_NodeIsSeriousGate(pObj) )
         {
diff --git a/src/base/io/ioWriteBlif.c b/src/base/io/ioWriteBlif.c
index 65546c01..88544d9f 100644
--- a/src/base/io/ioWriteBlif.c
+++ b/src/base/io/ioWriteBlif.c
@@ -615,9 +615,18 @@ int Io_NtkWriteNode( FILE * pFile, Abc_Obj_t * pNode, int Length )
     if ( Abc_NtkHasMapping(pNode->pNtk) )
     {
         // write the .gate line
-        fprintf( pFile, ".gate" );
-        RetValue = Io_NtkWriteNodeGate( pFile, pNode, Length );
-        fprintf( pFile, "\n" );
+        if ( Abc_ObjIsBarBuf(pNode) )
+        {
+            fprintf( pFile, ".barbuf " );
+            fprintf( pFile, "%s %s", Abc_ObjName(Abc_ObjFanin0(pNode)), Abc_ObjName(Abc_ObjFanout0(pNode)) );
+            fprintf( pFile, "\n" );
+        }
+        else
+        {
+            fprintf( pFile, ".gate" );
+            RetValue = Io_NtkWriteNodeGate( pFile, pNode, Length );
+            fprintf( pFile, "\n" );
+        }
     }
     else
     {
diff --git a/src/map/scl/sclBufSize.c b/src/map/scl/sclBufSize.c
index 96b00af1..7707704d 100644
--- a/src/map/scl/sclBufSize.c
+++ b/src/map/scl/sclBufSize.c
@@ -172,8 +172,6 @@ static inline float Abc_NtkComputeEdgeDept( Abc_Obj_t * pFanout, int iFanin, flo
     float Load = Bus_SclObjLoad( pFanout );
     float Dept = Bus_SclObjDept( pFanout );
     float Edge = Scl_LibPinArrivalEstimate( Abc_SclObjCell(pFanout), iFanin, Slew, Load );
-//if ( Abc_ObjFaninNum(pFanout) == 0 )
-//printf( "Edge = %.2f\n", Edge );
     assert( Edge > 0 );
     return Dept + Edge;
 }
@@ -183,8 +181,12 @@ float Abc_NtkComputeNodeDeparture( Abc_Obj_t * pObj, float Slew )
     int i;
     assert( Bus_SclObjDept(pObj) == 0 );
     Abc_ObjForEachFanout( pObj, pFanout, i )
-        if ( !Abc_ObjIsCo(pFanout) ) // add required times here
+    {
+        if ( Abc_ObjIsBarBuf(pFanout) )
+            Bus_SclObjUpdateDept( pObj, Bus_SclObjDept(pFanout) );
+        else if ( !Abc_ObjIsCo(pFanout) ) // add required times here
             Bus_SclObjUpdateDept( pObj, Abc_NtkComputeEdgeDept(pFanout, Abc_NodeFindFanin(pFanout, pObj), Slew) );
+    }
     return Bus_SclObjDept( pObj );
 }
 void Abc_NtkComputeFanoutInfo( Abc_Obj_t * pObj, float Slew )
@@ -192,12 +194,19 @@ void Abc_NtkComputeFanoutInfo( Abc_Obj_t * pObj, float Slew )
     Abc_Obj_t * pFanout;
     int i;
     Abc_ObjForEachFanout( pObj, pFanout, i )
-        if ( !Abc_ObjIsCo(pFanout) )
+    {
+        if ( Abc_ObjIsBarBuf(pFanout) )
+        {
+            Bus_SclObjSetETime( pFanout, Bus_SclObjDept(pFanout) );
+            Bus_SclObjSetCin( pFanout, Bus_SclObjLoad(pFanout) );
+        }
+        else if ( !Abc_ObjIsCo(pFanout) )
         {
             int iFanin = Abc_NodeFindFanin(pFanout, pObj);
             Bus_SclObjSetETime( pFanout, Abc_NtkComputeEdgeDept(pFanout, iFanin, Slew) );
             Bus_SclObjSetCin( pFanout, SC_CellPinCap( Abc_SclObjCell(pFanout), iFanin ) );
         }
+    }
 }
 float Abc_NtkComputeNodeLoad( Bus_Man_t * p, Abc_Obj_t * pObj )
 {
@@ -407,10 +416,12 @@ void Abc_SclBufSize( Bus_Man_t * p, float Gain )
         Abc_NtkComputeFanoutInfo( pObj, p->pPars->Slew );
         Load = Abc_NtkComputeNodeLoad( p, pObj );
         // consider the gate
-        if ( Abc_ObjIsCi(pObj) )
+        if ( Abc_ObjIsCi(pObj) || Abc_ObjIsBarBuf(pObj) )
         {
             pCell = p->pPiDrive;
-            Cin = SC_CellPinCapAve( pCell );
+            // if PI driver is not given, assume Cin to be equal to Load
+            // this way, buffering of the PIs is performed
+            Cin = pCell ? SC_CellPinCapAve(pCell) : Load;
         }
         else
         {
@@ -418,7 +429,7 @@ void Abc_SclBufSize( Bus_Man_t * p, float Gain )
             Cin = SC_CellPinCapAve( pCell->pAve );
 //        Cin = SC_CellPinCapAve( pCell->pRepr->pNext );
         }
-        // consider upsizing the gate
+        // consider buffering this gate
         if ( !p->pPars->fSizeOnly && (Abc_ObjFanoutNum(pObj) > p->pPars->nDegree || Load > GainGate * Cin) )
         {
             // add one or more inverters
@@ -448,6 +459,8 @@ void Abc_SclBufSize( Bus_Man_t * p, float Gain )
         if ( Abc_ObjIsCi(pObj) )
             continue;
         Abc_NtkComputeNodeDeparture( pObj, p->pPars->Slew );
+        if ( Abc_ObjIsBarBuf(pObj) )
+            continue;
         // create cell
         pCellNew = Abc_SclFindSmallestGate( pCell, Load / GainGate );
         Abc_SclObjSetCell( pObj, pCellNew );
diff --git a/src/map/scl/sclDnsize.c b/src/map/scl/sclDnsize.c
index c4bfc0b9..6060385e 100644
--- a/src/map/scl/sclDnsize.c
+++ b/src/map/scl/sclDnsize.c
@@ -239,7 +239,7 @@ void Abc_SclDnsizePrint( SC_Man * p, int Iter, int nAttempts, int nOverlaps, int
   SeeAlso     []
 
 ***********************************************************************/
-void Abc_SclDnsizePerform( SC_Lib * pLib, Abc_Ntk_t * pNtk, SC_SizePars * pPars )
+void Abc_SclDnsizePerformInt( SC_Lib * pLib, Abc_Ntk_t * pNtk, SC_SizePars * pPars )
 {
     SC_Man * p;
     Abc_Obj_t * pObj;
@@ -346,6 +346,29 @@ void Abc_SclDnsizePerform( SC_Lib * pLib, Abc_Ntk_t * pNtk, SC_SizePars * pPars
 //    Abc_NtkCleanMarkAB( pNtk );
 }
 
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Abc_SclDnsizePerform( SC_Lib * pLib, Abc_Ntk_t * pNtk, SC_SizePars * pPars )
+{
+    Abc_Ntk_t * pNtkNew = pNtk;
+    if ( pNtk->nBarBufs2 > 0 )
+        pNtkNew = Abc_NtkDupDfsNoBarBufs( pNtk );
+    Abc_SclDnsizePerformInt( pLib, pNtkNew, pPars );
+    if ( pNtk->nBarBufs2 > 0 )
+        Abc_SclTransferGates( pNtk, pNtkNew );
+    if ( pNtk->nBarBufs2 > 0 )
+        Abc_NtkDelete( pNtkNew );
+}
+
 ////////////////////////////////////////////////////////////////////////
 ///                       END OF FILE                                ///
 ////////////////////////////////////////////////////////////////////////
diff --git a/src/map/scl/sclSize.c b/src/map/scl/sclSize.c
index affe0652..d323df8b 100644
--- a/src/map/scl/sclSize.c
+++ b/src/map/scl/sclSize.c
@@ -668,7 +668,7 @@ SC_Man * Abc_SclManStart( SC_Lib * pLib, Abc_Ntk_t * pNtk, int fUseWireLoads, in
   SeeAlso     []
 
 ***********************************************************************/
-void Abc_SclTimePerform( SC_Lib * pLib, Abc_Ntk_t * pNtk, int nTreeCRatio, int fUseWireLoads, int fShowAll, int fPrintPath, int fDumpStats )
+void Abc_SclTimePerformInt( SC_Lib * pLib, Abc_Ntk_t * pNtk, int nTreeCRatio, int fUseWireLoads, int fShowAll, int fPrintPath, int fDumpStats )
 {
     SC_Man * p;
     p = Abc_SclManStart( pLib, pNtk, fUseWireLoads, 1, 0, nTreeCRatio );
@@ -678,6 +678,27 @@ void Abc_SclTimePerform( SC_Lib * pLib, Abc_Ntk_t * pNtk, int nTreeCRatio, int f
     Abc_SclManFree( p );
 }
 
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Abc_SclTimePerform( SC_Lib * pLib, Abc_Ntk_t * pNtk, int nTreeCRatio, int fUseWireLoads, int fShowAll, int fPrintPath, int fDumpStats )
+{
+    Abc_Ntk_t * pNtkNew = pNtk;
+    if ( pNtk->nBarBufs2 > 0 )
+        pNtkNew = Abc_NtkDupDfsNoBarBufs( pNtk );
+    Abc_SclTimePerformInt( pLib, pNtkNew, nTreeCRatio, fUseWireLoads, fShowAll, fPrintPath, fDumpStats );
+    if ( pNtk->nBarBufs2 > 0 )
+        Abc_NtkDelete( pNtkNew );
+}
+
 
 
 /**Function*************************************************************
diff --git a/src/map/scl/sclSize.h b/src/map/scl/sclSize.h
index 78c1f2f2..3ec0d83e 100644
--- a/src/map/scl/sclSize.h
+++ b/src/map/scl/sclSize.h
@@ -430,7 +430,7 @@ static inline int Abc_SclGetBufInvCount( Abc_Ntk_t * pNtk )
 {
     Abc_Obj_t * pObj;
     int i, Count = 0;
-    Abc_NtkForEachNode( pNtk, pObj, i )
+    Abc_NtkForEachNodeNotBarBuf1( pNtk, pObj, i )
         Count += (Abc_ObjFaninNum(pObj) == 1);
     return Count;
 }
@@ -439,7 +439,7 @@ static inline float Abc_SclGetAverageSize( Abc_Ntk_t * pNtk )
     Abc_Obj_t * pObj;
     double Total = 0;
     int i, Count = 0;
-    Abc_NtkForEachNode1( pNtk, pObj, i )
+    Abc_NtkForEachNodeNotBarBuf1( pNtk, pObj, i )
         Count++, Total += 100.0*Abc_SclObjCell(pObj)->Order/Abc_SclObjCell(pObj)->nGates;
     return (float)(Total / Count);
 }
@@ -448,7 +448,7 @@ static inline float Abc_SclGetTotalArea( Abc_Ntk_t * pNtk )
     double Area = 0;
     Abc_Obj_t * pObj;
     int i;
-    Abc_NtkForEachNode1( pNtk, pObj, i )
+    Abc_NtkForEachNodeNotBarBuf1( pNtk, pObj, i )
         Area += Abc_SclObjCell(pObj)->area;
     return Area;
 }
diff --git a/src/map/scl/sclUtil.c b/src/map/scl/sclUtil.c
index 5af1b88b..de33d50a 100644
--- a/src/map/scl/sclUtil.c
+++ b/src/map/scl/sclUtil.c
@@ -59,12 +59,9 @@ void Abc_SclMioGates2SclGates( SC_Lib * pLib, Abc_Ntk_t * p )
     // remap cells
     assert( p->vGates == NULL );
     p->vGates = Vec_IntStartFull( Abc_NtkObjNumMax(p) );
-    Abc_NtkForEachNode1( p, pObj, i )
+    Abc_NtkForEachNodeNotBarBuf1( p, pObj, i )
     {
-        if ( Abc_ObjIsBarBuf(pObj) )
-            gateId = bufferId;
-        else
-            gateId = Abc_SclCellFind( pLib, Mio_GateReadName((Mio_Gate_t *)pObj->pData) );
+        gateId = Abc_SclCellFind( pLib, Mio_GateReadName((Mio_Gate_t *)pObj->pData) );
         assert( gateId >= 0 );
         Vec_IntWriteEntry( p->vGates, i, gateId );
     }
@@ -76,14 +73,11 @@ void Abc_SclSclGates2MioGates( SC_Lib * pLib, Abc_Ntk_t * p )
     SC_Cell * pCell;
     int i, Counter = 0, CounterAll = 0;
     assert( p->vGates != NULL );
-    Abc_NtkForEachNode1( p, pObj, i )
+    Abc_NtkForEachNodeNotBarBuf1( p, pObj, i )
     {
         pCell = Abc_SclObjCell(pObj);
         assert( pCell->n_inputs == Abc_ObjFaninNum(pObj) );
-        if ( Abc_ObjIsBarBuf(pObj) )
-            pObj->pData = NULL;
-        else
-            pObj->pData = Mio_LibraryReadGateByName( (Mio_Library_t *)p->pManFunc, pCell->pName, NULL );
+        pObj->pData = Mio_LibraryReadGateByName( (Mio_Library_t *)p->pManFunc, pCell->pName, NULL );
         Counter += (pObj->pData == NULL);
         assert( pObj->fMarkA == 0 && pObj->fMarkB == 0 );
         CounterAll++;
@@ -110,12 +104,10 @@ void Abc_SclTransferGates( Abc_Ntk_t * pOld, Abc_Ntk_t * pNew )
     Abc_Obj_t * pObj; int i;
     assert( pOld->nBarBufs2 > 0 );
     assert( pNew->nBarBufs2 == 0 );
-    Abc_NtkForEachNode( pOld, pObj, i )
+    Abc_NtkForEachNodeNotBarBuf( pOld, pObj, i )
     {
         if ( pObj->pCopy == NULL )
             continue;
-        if ( Abc_ObjIsBarBuf(pObj) )
-            continue;
         assert( Abc_ObjNtk(pObj->pCopy) == pNew );
         pObj->pData = pObj->pCopy->pData;
     }
@@ -139,7 +131,7 @@ void Abc_SclManPrintGateSizes( SC_Lib * pLib, Abc_Ntk_t * p, Vec_Int_t * vGates
     SC_Cell * pCell;
     int i, nGates = 0, Counters[ABC_SCL_MAX_SIZE] = {0};
     double TotArea = 0, Areas[ABC_SCL_MAX_SIZE] = {0};
-    Abc_NtkForEachNode1( p, pObj, i )
+    Abc_NtkForEachNodeNotBarBuf1( p, pObj, i )
     {
         pCell = SC_LibCell( pLib, Vec_IntEntry(vGates, Abc_ObjId(pObj)) );
         assert( pCell->Order < ABC_SCL_MAX_SIZE );
@@ -216,7 +208,7 @@ void Abc_SclMinsizePerform( SC_Lib * pLib, Abc_Ntk_t * p, int fUseMax, int fVerb
     int i, gateId;
     vMinCells = Abc_SclFindMinAreas( pLib, fUseMax );
     Abc_SclMioGates2SclGates( pLib, p );
-    Abc_NtkForEachNode1( p, pObj, i )
+    Abc_NtkForEachNodeNotBarBuf1( p, pObj, i )
     {
         gateId = Vec_IntEntry( p->vGates, i );
         assert( gateId >= 0 && gateId < Vec_PtrSize(pLib->vCells) );
@@ -233,7 +225,7 @@ int Abc_SclCountMinSize( SC_Lib * pLib, Abc_Ntk_t * p, int fUseMax )
     Abc_Obj_t * pObj;
     int i, gateId, Counter = 0;
     vMinCells = Abc_SclFindMinAreas( pLib, fUseMax );
-    Abc_NtkForEachNode1( p, pObj, i )
+    Abc_NtkForEachNodeNotBarBuf1( p, pObj, i )
     {
         gateId = Vec_IntEntry( p->vGates, i );
         Counter += ( gateId == Vec_IntEntry(vMinCells, gateId) );