Added buffering based on combinational merging.

10 files changed, 376 insertions, 18 deletions

diff --git a/abclib.dsp b/abclib.dsp
index b13edf9e..b96fc9bf 100644
--- a/abclib.dsp
+++ b/abclib.dsp
@@ -2355,6 +2355,10 @@ SOURCE=.\src\map\scl\scl.h
 # End Source File
 # Begin Source File
 
+SOURCE=.\src\map\scl\sclBuff.c
+# End Source File
+# Begin Source File
+
 SOURCE=.\src\map\scl\sclFile.c
 # End Source File
 # Begin Source File
diff --git a/src/base/abc/abc.h b/src/base/abc/abc.h
index 9ed546e6..0d34ef2f 100644
--- a/src/base/abc/abc.h
+++ b/src/base/abc/abc.h
@@ -705,6 +705,7 @@ extern ABC_DLL void               Abc_NtkFinalize( Abc_Ntk_t * pNtk, Abc_Ntk_t *
 extern ABC_DLL Abc_Ntk_t *        Abc_NtkStartRead( char * pName );
 extern ABC_DLL void               Abc_NtkFinalizeRead( Abc_Ntk_t * pNtk );
 extern ABC_DLL Abc_Ntk_t *        Abc_NtkDup( Abc_Ntk_t * pNtk );
+extern ABC_DLL Abc_Ntk_t *        Abc_NtkDupDfs( Abc_Ntk_t * pNtk );
 extern ABC_DLL Abc_Ntk_t *        Abc_NtkDupTransformMiter( Abc_Ntk_t * pNtk );
 extern ABC_DLL Abc_Ntk_t *        Abc_NtkCreateCone( Abc_Ntk_t * pNtk, Abc_Obj_t * pNode, char * pNodeName, int fUseAllCis );
 extern ABC_DLL Abc_Ntk_t *        Abc_NtkCreateConeArray( Abc_Ntk_t * pNtk, Vec_Ptr_t * vRoots, int fUseAllCis );
diff --git a/src/base/abc/abcNtk.c b/src/base/abc/abcNtk.c
index 2f28f54c..5f9c0f0d 100644
--- a/src/base/abc/abcNtk.c
+++ b/src/base/abc/abcNtk.c
@@ -350,9 +350,6 @@ Abc_Ntk_t * Abc_NtkDup( Abc_Ntk_t * pNtk )
         return NULL;
     // start the network
     pNtkNew = Abc_NtkStartFrom( pNtk, pNtk->ntkType, pNtk->ntkFunc );
-    // transfer level
-    Abc_NtkForEachCi( pNtk, pObj, i )
-        pObj->pCopy->Level = pObj->Level;
     // copy the internal nodes
     if ( Abc_NtkIsStrash(pNtk) )
     {
@@ -406,6 +403,42 @@ Abc_Ntk_t * Abc_NtkDup( Abc_Ntk_t * pNtk )
     pNtk->pCopy = pNtkNew;
     return pNtkNew;
 }
+Abc_Ntk_t * Abc_NtkDupDfs( Abc_Ntk_t * pNtk )
+{
+    Vec_Ptr_t * vNodes;
+    Abc_Ntk_t * pNtkNew; 
+    Abc_Obj_t * pObj, * pFanin;
+    int i, k;
+    if ( pNtk == NULL )
+        return NULL;
+    assert( !Abc_NtkIsStrash(pNtk) && !Abc_NtkIsNetlist(pNtk) );
+    // start the network
+    pNtkNew = Abc_NtkStartFrom( pNtk, pNtk->ntkType, pNtk->ntkFunc );
+    // copy the internal nodes
+    vNodes = Abc_NtkDfs( pNtk, 0 );
+    Vec_PtrForEachEntry( Abc_Obj_t *, vNodes, pObj, i )
+        Abc_NtkDupObj( pNtkNew, pObj, 0 );
+    Vec_PtrFree( vNodes );
+    // reconnect all objects (no need to transfer attributes on edges)
+    Abc_NtkForEachObj( pNtk, pObj, i )
+        if ( !Abc_ObjIsBox(pObj) && !Abc_ObjIsBo(pObj) )
+            Abc_ObjForEachFanin( pObj, pFanin, k )
+                if ( pObj->pCopy && pFanin->pCopy )
+                    Abc_ObjAddFanin( pObj->pCopy, pFanin->pCopy );
+    // duplicate the EXDC Ntk
+    if ( pNtk->pExdc )
+        pNtkNew->pExdc = Abc_NtkDup( pNtk->pExdc );
+    if ( pNtk->pExcare )
+        pNtkNew->pExcare = Abc_NtkDup( (Abc_Ntk_t *)pNtk->pExcare );
+    // duplicate timing manager
+    if ( pNtk->pManTime )
+        Abc_NtkTimeInitialize( pNtkNew, pNtk );
+    // check correctness
+    if ( !Abc_NtkCheck( pNtkNew ) )
+        fprintf( stdout, "Abc_NtkDup(): Network check has failed.\n" );
+    pNtk->pCopy = pNtkNew;
+    return pNtkNew;
+}
 
 /**Function*************************************************************
 
diff --git a/src/base/abci/abc.c b/src/base/abci/abc.c
index 9c1bd720..c192b809 100644
--- a/src/base/abci/abc.c
+++ b/src/base/abci/abc.c
@@ -9385,14 +9385,17 @@ int Abc_CommandTest( Abc_Frame_t * pAbc, int argc, char ** argv )
     extern Aig_Man_t * Abc_NtkToDarBmc( Abc_Ntk_t * pNtk, Vec_Int_t ** pvMap );
     extern void Abc2_NtkTestGia( char * pFileName, int fVerbose );
     extern void Saig_ManBmcTerSimTestPo( Aig_Man_t * p );
+    extern int Abc_SclCheckNtk( Abc_Ntk_t * p );
+    extern void Abc_SclPerformBuffering( Abc_Ntk_t * p, int Degree );
 
     if ( pNtk )
     {
-
+/*
         Aig_Man_t * pAig = Abc_NtkToDar( pNtk, 0, 1 );
         Saig_ManBmcTerSimTestPo( pAig );
         Aig_ManStop( pAig );
-
+*/
+        Abc_SclPerformBuffering( pNtk, nDecMax );
 /*
         extern Abc_Ntk_t * Abc_NtkShareXor( Abc_Ntk_t * pNtk );
         Abc_Ntk_t * pNtkRes = Abc_NtkShareXor( pNtk );
diff --git a/src/map/scl/module.make b/src/map/scl/module.make
index d6731980..1e926e4b 100644
--- a/src/map/scl/module.make
+++ b/src/map/scl/module.make
@@ -1,4 +1,5 @@
 SRC +=  src/map/scl/scl.c \
+    src/map/scl/sclBuff.c \
     src/map/scl/sclFile.c \
     src/map/scl/sclSize.c \
     src/map/scl/sclTime.c \
diff --git a/src/map/scl/scl.c b/src/map/scl/scl.c
index 73cd6552..cbe7b3aa 100644
--- a/src/map/scl/scl.c
+++ b/src/map/scl/scl.c
@@ -27,11 +27,12 @@ ABC_NAMESPACE_IMPL_START
 ///                        DECLARATIONS                              ///
 ////////////////////////////////////////////////////////////////////////
 
-static int Scl_CommandRead ( Abc_Frame_t * pAbc, int argc, char **argv );
-static int Scl_CommandWrite( Abc_Frame_t * pAbc, int argc, char **argv );
-static int Scl_CommandPrint( Abc_Frame_t * pAbc, int argc, char **argv );
-static int Scl_CommandStime( Abc_Frame_t * pAbc, int argc, char **argv );
-static int Scl_CommandGsize( Abc_Frame_t * pAbc, int argc, char **argv );
+static int Scl_CommandRead  ( Abc_Frame_t * pAbc, int argc, char **argv );
+static int Scl_CommandWrite ( Abc_Frame_t * pAbc, int argc, char **argv );
+static int Scl_CommandPrint ( Abc_Frame_t * pAbc, int argc, char **argv );
+static int Scl_CommandStime ( Abc_Frame_t * pAbc, int argc, char **argv );
+static int Scl_CommandGsize ( Abc_Frame_t * pAbc, int argc, char **argv );
+static int Scl_CommandBuffer( Abc_Frame_t * pAbc, int argc, char **argv );
 
 ////////////////////////////////////////////////////////////////////////
 ///                     FUNCTION DEFINITIONS                         ///
@@ -50,11 +51,12 @@ static int Scl_CommandGsize( Abc_Frame_t * pAbc, int argc, char **argv );
 ***********************************************************************/
 void Scl_Init( Abc_Frame_t * pAbc )
 {
-    Cmd_CommandAdd( pAbc, "SC mapping",  "read_scl",   Scl_CommandRead,  0 ); 
-    Cmd_CommandAdd( pAbc, "SC mapping",  "write_scl",  Scl_CommandWrite, 0 ); 
-    Cmd_CommandAdd( pAbc, "SC mapping",  "print_scl",  Scl_CommandPrint, 0 ); 
-    Cmd_CommandAdd( pAbc, "SC mapping",  "stime",      Scl_CommandStime, 0 ); 
-    Cmd_CommandAdd( pAbc, "SC mapping",  "gsize",      Scl_CommandGsize, 1 ); 
+    Cmd_CommandAdd( pAbc, "SC mapping",  "read_scl",   Scl_CommandRead,   0 ); 
+    Cmd_CommandAdd( pAbc, "SC mapping",  "write_scl",  Scl_CommandWrite,  0 ); 
+    Cmd_CommandAdd( pAbc, "SC mapping",  "print_scl",  Scl_CommandPrint,  0 ); 
+    Cmd_CommandAdd( pAbc, "SC mapping",  "stime",      Scl_CommandStime,  0 ); 
+    Cmd_CommandAdd( pAbc, "SC mapping",  "gsize",      Scl_CommandGsize,  1 ); 
+    Cmd_CommandAdd( pAbc, "SC mapping",  "buffer",     Scl_CommandBuffer, 1 ); 
 }
 void Scl_End( Abc_Frame_t * pAbc )
 {
@@ -321,6 +323,83 @@ usage:
     return 1;
 }
 
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int Scl_CommandBuffer( Abc_Frame_t * pAbc, int argc, char ** argv )
+{
+    extern Abc_Ntk_t * Abc_SclPerformBuffering( Abc_Ntk_t * p, int Degree, int fVerbose );
+    Abc_Ntk_t * pNtk = Abc_FrameReadNtk(pAbc);
+    Abc_Ntk_t * pNtkRes;
+    int Degree;
+    int c, fVerbose;
+    Degree   = 3;
+    fVerbose = 0;
+    Extra_UtilGetoptReset();
+    while ( ( c = Extra_UtilGetopt( argc, argv, "Nvh" ) ) != EOF )
+    {
+        switch ( c )
+        {
+        case 'N':
+            if ( globalUtilOptind >= argc )
+            {
+                Abc_Print( -1, "Command line switch \"-N\" should be followed by a positive integer.\n" );
+                goto usage;
+            }
+            Degree = atoi(argv[globalUtilOptind]);
+            globalUtilOptind++;
+            if ( Degree < 0 ) 
+                goto usage;
+            break;
+        case 'v':
+            fVerbose ^= 1;
+            break;
+        case 'h':
+            goto usage;
+        default:
+            goto usage;
+        }
+    }
+
+    if ( pNtk == NULL )
+    {
+        Abc_Print( -1, "Empty network.\n" );
+        return 1;
+    }
+    if ( !Abc_NtkIsLogic(pNtk) )
+    {
+        Abc_Print( -1, "This command can only be applied to a logic network.\n" );
+        return 1;
+    }
+
+    // modify the current network
+    pNtkRes = Abc_SclPerformBuffering( pNtk, Degree, fVerbose );
+    if ( pNtkRes == NULL )
+    {
+        Abc_Print( -1, "The command has failed.\n" );
+        return 1;
+    }
+    // replace the current network
+    Abc_FrameReplaceCurrentNetwork( pAbc, pNtkRes );
+    return 0;
+
+usage:
+    Abc_Print( -2, "usage: buffer [-N num] [-vh]\n" );
+    Abc_Print( -2, "\t           performs buffering of the mapped network\n" );
+    Abc_Print( -2, "\t-N <num> : the number of refinement iterations [default = %d]\n", Degree );
+    Abc_Print( -2, "\t-v       : toggle printing optimization summary [default = %s]\n", fVerbose? "yes": "no" );
+    Abc_Print( -2, "\t-h       : print the command usage\n");
+    return 1;
+} 
+
 
 ////////////////////////////////////////////////////////////////////////
 ///                       END OF FILE                                ///
diff --git a/src/map/scl/sclBuff.c b/src/map/scl/sclBuff.c
new file mode 100644
index 00000000..d435ae92
--- /dev/null
+++ b/src/map/scl/sclBuff.c
@@ -0,0 +1,219 @@
+/**CFile****************************************************************
+
+  FileName    [sclBuff.c]
+
+  SystemName  [ABC: Logic synthesis and verification system.]
+
+  Synopsis    [Standard-cell library representation.]
+
+  Author      [Alan Mishchenko, Niklas Een]
+  
+  Affiliation [UC Berkeley]
+
+  Date        [Ver. 1.0. Started - August 24, 2012.]
+
+  Revision    [$Id: sclBuff.c,v 1.0 2012/08/24 00:00:00 alanmi Exp $]
+
+***********************************************************************/
+
+#include "base/abc/abc.h"
+#include "map/mio/mio.h"
+#include "sclInt.h"
+
+ABC_NAMESPACE_IMPL_START
+
+
+////////////////////////////////////////////////////////////////////////
+///                        DECLARATIONS                              ///
+////////////////////////////////////////////////////////////////////////
+
+////////////////////////////////////////////////////////////////////////
+///                     FUNCTION DEFINITIONS                         ///
+////////////////////////////////////////////////////////////////////////
+
+/**Function*************************************************************
+
+  Synopsis    [Make sure the network has no dangling nodes.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int Abc_SclCheckNtk( Abc_Ntk_t * p, int fVerbose )
+{
+    Abc_Obj_t * pObj, * pFanin;
+    int i, k, fFlag = 0;
+    Abc_NtkIncrementTravId( p );        
+    Abc_NtkForEachCi( p, pObj, i )
+        Abc_NodeSetTravIdCurrent( pObj );
+    Abc_NtkForEachNode( p, pObj, i )
+    {
+        Abc_ObjForEachFanin( pObj, pFanin, k )
+            if ( !Abc_NodeIsTravIdCurrent( pFanin ) )
+                printf( "obj %d and its fanin %d are not in the topo order\n", Abc_ObjId(pObj), Abc_ObjId(pFanin) ), fFlag = 1;
+        Abc_NodeSetTravIdCurrent( pObj );
+        if ( Abc_ObjFanoutNum(pObj) == 0 )
+            printf( "node %d has no fanout\n", Abc_ObjId(pObj) ), fFlag = 1;
+    }
+    if ( !fFlag && fVerbose )
+        printf( "The network is in topo order and no dangling nodes.\n" );
+    return 1;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Make sure the network has no dangling nodes.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int Abc_SclCheckNtk2( Abc_Ntk_t * p )
+{
+    Abc_Obj_t * pObj, * pFanout;
+    int i, k, fFlag = 0;
+    Abc_NtkStartReverseLevels( p, 0 );
+    Abc_NtkForEachNode( p, pObj, i )
+    {
+        if ( Abc_ObjFanoutNum(pObj) <= 3 )
+            continue;
+        printf( "Node %5d (%2d) : fans = %3d  ", i, Abc_ObjLevel(pObj), Abc_ObjFanoutNum(pObj) );
+        Abc_ObjForEachFanout( pObj, pFanout, k )
+            printf( "%d ", Abc_ObjReverseLevel(pFanout) );
+        printf( "\n" );
+    }
+    return 1;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Performs buffering of the mapped network.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int Abc_NodeCompareLevels( Abc_Obj_t ** pp1, Abc_Obj_t ** pp2 )
+{
+    int Diff = Abc_ObjLevel(*pp1) - Abc_ObjLevel(*pp2);
+    if ( Diff < 0 )
+        return -1;
+    if ( Diff > 0 ) 
+        return 1;
+    Diff = (*pp1)->Id - (*pp2)->Id;
+    if ( Diff < 0 )
+        return -1;
+    if ( Diff > 0 ) 
+        return 1;
+    return 0; 
+}
+int Abc_SclComputeReverseLevel( Abc_Obj_t * pObj )
+{
+    Abc_Obj_t * pFanout;
+    int i, Level = 0;
+    Abc_ObjForEachFanout( pObj, pFanout, i )
+        Level = Abc_MaxInt( Level, pFanout->Level );
+    return Level + 1;
+}
+Abc_Obj_t * Abc_SclPerformBufferingOne( Abc_Obj_t * pObj, int Degree, int fVerbose )
+{
+    Vec_Ptr_t * vFanouts;
+    Abc_Obj_t * pBuffer, * pFanout;
+    int i, Degree0 = Degree;
+    assert( Abc_ObjFanoutNum(pObj) > Degree );
+    // collect fanouts and sort by reverse level
+    vFanouts = Vec_PtrAlloc( Abc_ObjFanoutNum(pObj) );
+    Abc_NodeCollectFanouts( pObj, vFanouts );
+    Vec_PtrSort( vFanouts, Abc_NodeCompareLevels );
+    // select the first Degree fanouts
+    pBuffer = Abc_NtkCreateNodeBuf( pObj->pNtk, NULL );
+    // check if it is possible to not increase level
+    if ( Vec_PtrSize(vFanouts) < 2 * Degree )
+    {
+        Abc_Obj_t * pFanPrev = (Abc_Obj_t *)Vec_PtrEntry(vFanouts, Vec_PtrSize(vFanouts)-1-Degree);
+        Abc_Obj_t * pFanThis = (Abc_Obj_t *)Vec_PtrEntry(vFanouts, Degree-1);
+        Abc_Obj_t * pFanLast = (Abc_Obj_t *)Vec_PtrEntryLast(vFanouts);
+        if ( Abc_ObjLevel(pFanThis) == Abc_ObjLevel(pFanLast) &&
+             Abc_ObjLevel(pFanPrev) <  Abc_ObjLevel(pFanThis) )
+        {
+            // find the first one whose level is the same as last
+            Vec_PtrForEachEntry( Abc_Obj_t *, vFanouts, pFanout, i )
+                if ( Abc_ObjLevel(pFanout) == Abc_ObjLevel(pFanLast) )
+                    break;
+            assert( i < Vec_PtrSize(vFanouts) );
+            if ( i > 1 )
+                Degree = i;
+        }
+        // make the last two more well-balanced
+        if ( Degree == Degree0 && Degree > Vec_PtrSize(vFanouts) - Degree )
+            Degree = Vec_PtrSize(vFanouts)/2 + (Vec_PtrSize(vFanouts) & 1);
+        assert( Degree <= Degree0 );
+    }
+    // select fanouts
+    Vec_PtrForEachEntryStop( Abc_Obj_t *, vFanouts, pFanout, i, Degree )
+        Abc_ObjPatchFanin( pFanout, pObj, pBuffer );
+    if ( fVerbose )
+    {
+        printf( "%5d : ", Abc_ObjId(pObj) );
+        Vec_PtrForEachEntry( Abc_Obj_t *, vFanouts, pFanout, i )
+            printf( "%d%s ", Abc_ObjLevel(pFanout), i == Degree-1 ? "  " : "" );
+        printf( "\n" );
+    }
+    Vec_PtrFree( vFanouts );
+    Abc_ObjAddFanin( pBuffer, pObj );
+    pBuffer->Level = Abc_SclComputeReverseLevel( pBuffer );
+    return pBuffer;
+}
+void Abc_SclPerformBuffering_rec( Abc_Obj_t * pObj, int Degree, int fVerbose )
+{
+    Abc_Obj_t * pFanout;
+    int i;
+    if ( Abc_NodeIsTravIdCurrent( pObj ) )
+        return;
+    Abc_NodeSetTravIdCurrent( pObj );
+    pObj->Level = 0;
+    if ( Abc_ObjIsCo(pObj) )
+        return;
+    assert( Abc_ObjIsCi(pObj) || Abc_ObjIsNode(pObj) );
+    // buffer fanouts and collect reverse levels
+    Abc_ObjForEachFanout( pObj, pFanout, i )
+        Abc_SclPerformBuffering_rec( pFanout, Degree, fVerbose );
+    // perform buffering as long as needed
+    while ( Abc_ObjFanoutNum(pObj) > Degree )
+        Abc_SclPerformBufferingOne( pObj, Degree, fVerbose );
+    // compute the new level of the node
+    pObj->Level = Abc_SclComputeReverseLevel( pObj );
+}
+Abc_Ntk_t * Abc_SclPerformBuffering( Abc_Ntk_t * p, int Degree, int fVerbose )
+{
+    Abc_Ntk_t * pNew;
+    Abc_Obj_t * pObj;
+    int i;
+    assert( Abc_NtkHasMapping(p) );
+    Abc_NtkIncrementTravId( p );        
+    Abc_NtkForEachCi( p, pObj, i )
+        Abc_SclPerformBuffering_rec( pObj, Degree, fVerbose );
+    Abc_NtkLevel( p );
+    // duplication in topo order
+    pNew = Abc_NtkDupDfs( p );
+    Abc_SclCheckNtk( pNew, fVerbose );
+//    Abc_NtkDelete( pNew );
+    return pNew;
+}
+
+////////////////////////////////////////////////////////////////////////
+///                       END OF FILE                                ///
+////////////////////////////////////////////////////////////////////////
+
+
+ABC_NAMESPACE_IMPL_END
+
diff --git a/src/map/scl/sclInt.h b/src/map/scl/sclInt.h
index 8b9b0eec..b9a78f75 100644
--- a/src/map/scl/sclInt.h
+++ b/src/map/scl/sclInt.h
@@ -385,7 +385,6 @@ extern int      Abc_SclCellFind( SC_Lib * p, char * pName );
 extern void     Abc_SclLinkCells( SC_Lib * p );
 extern void     Abc_SclPrintCells( SC_Lib * p );
 
-
 ABC_NAMESPACE_HEADER_END
 
 #endif
diff --git a/src/map/scl/sclSize.c b/src/map/scl/sclSize.c
index 8270bcea..850a2501 100644
--- a/src/map/scl/sclSize.c
+++ b/src/map/scl/sclSize.c
@@ -1,6 +1,6 @@
 /**CFile****************************************************************
 
-  FileName    [sclIo.c]
+  FileName    [sclSize.c]
 
   SystemName  [ABC: Logic synthesis and verification system.]
 
@@ -12,7 +12,7 @@
 
   Date        [Ver. 1.0. Started - August 24, 2012.]
 
-  Revision    [$Id: sclIo.c,v 1.0 2012/08/24 00:00:00 alanmi Exp $]
+  Revision    [$Id: sclSize.c,v 1.0 2012/08/24 00:00:00 alanmi Exp $]
 
 ***********************************************************************/
 
diff --git a/src/map/scl/sclTime.c b/src/map/scl/sclTime.c
index 45eb4ee5..160478c2 100644
--- a/src/map/scl/sclTime.c
+++ b/src/map/scl/sclTime.c
@@ -259,6 +259,23 @@ Abc_Obj_t * Abc_SclFindMostCritical( SC_Man * p, int * pfRise, Vec_Ptr_t * vNode
     assert( pPivot != NULL );
     return pPivot;
 }
+Abc_Obj_t * Abc_SclFindMostCriticalFanin( SC_Man * p, int * pfRise, Abc_Obj_t * pNode )
+{
+    Abc_Obj_t * pObj, * pPivot = NULL;
+    float fMaxArr = 0;
+    int i;
+    Abc_ObjForEachFanin( pNode, pObj, i )
+    {
+        SC_Pair * pArr = Abc_SclObjArr( p, pObj );
+        if ( fMaxArr < pArr->rise )  fMaxArr = pArr->rise, *pfRise = 1, pPivot = pObj;
+        if ( fMaxArr < pArr->fall )  fMaxArr = pArr->fall, *pfRise = 0, pPivot = pObj;
+    }
+    assert( pPivot != NULL );
+    return pPivot;
+}
+void Abc_SclCriticalPathPrint( SC_Man * p, Vec_Ptr_t * vNodes )
+{
+}
 void Abc_SclTimeNtkPrint( SC_Man * p, Vec_Ptr_t * vNodes )
 {
 /*
@@ -385,6 +402,7 @@ void Abc_SclTimeNtk( SC_Man * p )
     Vec_PtrFree( vNodes );
 }
 
+
 /**Function*************************************************************
 
   Synopsis    []
@@ -399,6 +417,7 @@ void Abc_SclTimeNtk( SC_Man * p )
 void Abc_SclTimePerform( SC_Lib * pLib, void * pNtk )
 {
     SC_Man * p;
+
     p = Abc_SclManAlloc( pLib, (Abc_Ntk_t *)pNtk );
     Abc_SclTimeNtk( p );
     Abc_SclManFree( p );