Improvements to buffering and sizing.

src/base/abc/abc.h

@@ -205,6 +205,7 @@ struct Abc_Ntk_t_
     void *            pData;         // misc
     Abc_Ntk_t *       pCopy;         // copy of this network
     Vec_Int_t *       vPhases;       // fanins phases in the mapped netlist
+    char *            pWLoadUsed;    // wire load model used
     float *           pLutTimes;     // arrivals/requireds/slacks using LUT-delay model
     Vec_Ptr_t *       vOnehots;      // names of one-hot-encoded registers
     Vec_Int_t *       vObjPerm;      // permutation saved

src/base/abc/abcNtk.c

@@ -325,6 +325,8 @@ void Abc_NtkFinalize( Abc_Ntk_t * pNtk, Abc_Ntk_t * pNtkNew )
         Abc_NtkTimeInitialize( pNtkNew, pNtk );
     if ( pNtk->vPhases )
         Abc_NtkTransferPhases( pNtkNew, pNtk );
+    if ( pNtk->pWLoadUsed )
+        pNtkNew->pWLoadUsed = Abc_UtilStrsav( pNtk->pWLoadUsed );
 }
 
 /**Function*************************************************************
@@ -482,6 +484,8 @@ Abc_Ntk_t * Abc_NtkDup( Abc_Ntk_t * pNtk )
         Abc_NtkTimeInitialize( pNtkNew, pNtk );
     if ( pNtk->vPhases )
         Abc_NtkTransferPhases( pNtkNew, pNtk );
+    if ( pNtk->pWLoadUsed )
+        pNtkNew->pWLoadUsed = Abc_UtilStrsav( pNtk->pWLoadUsed );
     // check correctness
     if ( !Abc_NtkCheck( pNtkNew ) )
         fprintf( stdout, "Abc_NtkDup(): Network check has failed.\n" );
@@ -520,6 +524,8 @@ Abc_Ntk_t * Abc_NtkDupDfs( Abc_Ntk_t * pNtk )
         Abc_NtkTimeInitialize( pNtkNew, pNtk );
     if ( pNtk->vPhases )
         Abc_NtkTransferPhases( pNtkNew, pNtk );
+    if ( pNtk->pWLoadUsed )
+        pNtkNew->pWLoadUsed = Abc_UtilStrsav( pNtk->pWLoadUsed );
     // check correctness
     if ( !Abc_NtkCheck( pNtkNew ) )
         fprintf( stdout, "Abc_NtkDup(): Network check has failed.\n" );
@@ -1346,6 +1352,7 @@ void Abc_NtkDelete( Abc_Ntk_t * pNtk )
             Vec_AttFree( (Vec_Att_t *)pAttrMan, 1 );
         }
     Vec_PtrFree( pNtk->vAttrs );
+    ABC_FREE( pNtk->pWLoadUsed );
     ABC_FREE( pNtk->pName );
     ABC_FREE( pNtk->pSpec );
     ABC_FREE( pNtk->pLutTimes );

src/map/scl/scl.c

@@ -904,13 +904,14 @@ int Scl_CommandUpsize( Abc_Frame_t * pAbc, int argc, char **argv )
     pPars->DelayGap      =    0;
     pPars->TimeOut       =    0;
     pPars->BuffTreeEst   =    0;
+    pPars->BypassFreq    =    0;
     pPars->fUseDept      =    1;
     pPars->fUseWireLoads =    1;
     pPars->fDumpStats    =    0;
     pPars->fVerbose      =    0;
     pPars->fVeryVerbose  =    0;
     Extra_UtilGetoptReset();
-    while ( ( c = Extra_UtilGetopt( argc, argv, "IJWRNDGTXcsdvwh" ) ) != EOF )
+    while ( ( c = Extra_UtilGetopt( argc, argv, "IJWRNDGTXBcsdvwh" ) ) != EOF )
     {
         switch ( c )
         {
@@ -1011,6 +1012,17 @@ int Scl_CommandUpsize( Abc_Frame_t * pAbc, int argc, char **argv )
             if ( pPars->BuffTreeEst < 0 ) 
                 goto usage;
             break;
+        case 'B':
+            if ( globalUtilOptind >= argc )
+            {
+                Abc_Print( -1, "Command line switch \"-B\" should be followed by a positive integer.\n" );
+                goto usage;
+            }
+            pPars->BypassFreq = atoi(argv[globalUtilOptind]);
+            globalUtilOptind++;
+            if ( pPars->BypassFreq < 0 ) 
+                goto usage;
+            break;
         case 'c':
             pPars->fUseWireLoads ^= 1;
             break;
@@ -1058,7 +1070,7 @@ int Scl_CommandUpsize( Abc_Frame_t * pAbc, int argc, char **argv )
     return 0;
 
 usage:
-    fprintf( pAbc->Err, "usage: upsize [-IJWRNDGTX num] [-csdvwh]\n" );
+    fprintf( pAbc->Err, "usage: upsize [-IJWRNDGTXB num] [-csdvwh]\n" );
     fprintf( pAbc->Err, "\t           selectively increases gate sizes on the critical path\n" );
     fprintf( pAbc->Err, "\t-I <num> : the number of upsizing iterations to perform [default = %d]\n", pPars->nIters );
     fprintf( pAbc->Err, "\t-J <num> : the number of iterations without improvement to stop [default = %d]\n", pPars->nIterNoChange );
@@ -1069,6 +1081,7 @@ usage:
     fprintf( pAbc->Err, "\t-G <num> : delay gap during updating, in picoseconds [default = %d]\n", pPars->DelayGap );
     fprintf( pAbc->Err, "\t-T <num> : approximate timeout in seconds [default = %d]\n", pPars->TimeOut );
     fprintf( pAbc->Err, "\t-X <num> : ratio for buffer tree estimation [default = %d]\n", pPars->BuffTreeEst );
+    fprintf( pAbc->Err, "\t-B <num> : frequency of bypass transforms [default = %d]\n", pPars->BypassFreq );
     fprintf( pAbc->Err, "\t-c       : toggle using wire-loads if specified [default = %s]\n", pPars->fUseWireLoads? "yes": "no" );
     fprintf( pAbc->Err, "\t-s       : toggle using slack based on departure times [default = %s]\n", pPars->fUseDept? "yes": "no" );
     fprintf( pAbc->Err, "\t-d       : toggle dumping statistics into a file [default = %s]\n", pPars->fDumpStats? "yes": "no" );

src/map/scl/sclBuffer.c

@@ -113,7 +113,7 @@ static inline int Abc_SclObjIsBufInv( Abc_Obj_t * pObj )
 {
     return Abc_ObjIsNode(pObj) && Abc_ObjFaninNum(pObj) == 1;
 }
-static inline int Abc_SclIsInv( Abc_Obj_t * pObj )
+int Abc_SclIsInv( Abc_Obj_t * pObj )
 {
     assert( Abc_ObjIsNode(pObj) );
     return Mio_GateReadTruth((Mio_Gate_t *)pObj->pData) == ABC_CONST(0x5555555555555555);
@@ -315,7 +315,7 @@ int Abc_SclCheckNtk( Abc_Ntk_t * p, int fVerbose )
   SeeAlso     []
 
 ***********************************************************************/
-void Abc_NodeInvUpdateFanPolarity( Abc_Obj_t * pObj )
+void Abc_NodeInvUpdateFanPolarity( Abc_Obj_t * pObj, int fVerbose )
 {
     Abc_Obj_t * pFanout;
     int i;
@@ -323,12 +323,23 @@ void Abc_NodeInvUpdateFanPolarity( Abc_Obj_t * pObj )
     Abc_ObjForEachFanout( pObj, pFanout, i )
     {
         if ( Abc_SclObjIsBufInv(pFanout) )
-            Abc_NodeInvUpdateFanPolarity( pFanout );
+            Abc_NodeInvUpdateFanPolarity( pFanout, fVerbose );
         else
+        {
             Abc_ObjFaninFlipPhase( pFanout, Abc_NodeFindFanin(pFanout, pObj) );
+//            if ( fVerbose )
+//                printf( "Flipping fanin %d of node %d.\n", Abc_NodeFindFanin(pFanout, pObj), Abc_ObjId(pFanout) );
+        }
     }
 }
-
+void Abc_NodeInvUpdateObjFanoutPolarity( Abc_Obj_t * pObj, Abc_Obj_t * pFanout )
+{
+    if ( Abc_SclObjIsBufInv(pFanout) )
+        Abc_NodeInvUpdateFanPolarity( pFanout, 1 );
+    else
+        Abc_ObjFaninFlipPhase( pFanout, Abc_NodeFindFanin(pFanout, pObj) );
+//    printf( "\n" );
+}
 int Abc_NodeCompareLevels( Abc_Obj_t ** pp1, Abc_Obj_t ** pp2 )
 {
     int Diff = Abc_ObjLevel(*pp1) - Abc_ObjLevel(*pp2);
@@ -402,7 +413,7 @@ Abc_Obj_t * Abc_SclPerformBufferingOne( Abc_Obj_t * pObj, int Degree, int fUseIn
     Abc_ObjAddFanin( pBuffer, pObj );
     pBuffer->Level = Abc_SclComputeReverseLevel( pBuffer );
     if ( fUseInvs )
-        Abc_NodeInvUpdateFanPolarity( pBuffer );
+        Abc_NodeInvUpdateFanPolarity( pBuffer, 0 );
     return pBuffer;
 }
 void Abc_SclPerformBuffering_rec( Abc_Obj_t * pObj, int DegreeR, int Degree, int fUseInvs, int fVerbose )
@@ -440,7 +451,7 @@ void Abc_SclPerformBuffering_rec( Abc_Obj_t * pObj, int DegreeR, int Degree, int
         Abc_ObjAddFanin( pBuffer, pObj );
         pBuffer->Level = Abc_SclComputeReverseLevel( pBuffer );
         if ( fUseInvs )
-            Abc_NodeInvUpdateFanPolarity( pBuffer );
+            Abc_NodeInvUpdateFanPolarity( pBuffer, 0 );
     }
     // compute the new level of the node
     pObj->Level = Abc_SclComputeReverseLevel( pObj );

src/map/scl/sclLib.c

@@ -807,9 +807,25 @@ void Abc_SclLinkCells( SC_Lib * p )
   SeeAlso     []
 
 ***********************************************************************/
-SC_WireLoad * Abc_SclFindWireLoadModel( SC_Lib * p, float Area )
+SC_WireLoad * Abc_SclFetchWireLoadModel( SC_Lib * p, char * pWLoadUsed )
 {
     SC_WireLoad * pWL = NULL;
+    int i;
+    // Get the actual table and reformat it for 'wire_cap' output:
+    assert( pWLoadUsed != NULL );
+    SC_LibForEachWireLoad( p, pWL, i )
+        if ( !strcmp(pWL->pName, pWLoadUsed) )
+            break;
+    if ( i == Vec_PtrSize(p->vWireLoads) )
+    {
+        Abc_Print( -1, "Cannot find wire load model \"%s\".\n", pWLoadUsed );
+        exit(1);
+    }
+//    printf( "Using wireload model \"%s\".\n", pWL->pName );
+    return pWL;
+}
+SC_WireLoad * Abc_SclFindWireLoadModel( SC_Lib * p, float Area )
+{
     char * pWLoadUsed = NULL;
     int i;
     if ( p->default_wire_load_sel && strlen(p->default_wire_load_sel) )
@@ -839,18 +855,7 @@ SC_WireLoad * Abc_SclFindWireLoadModel( SC_Lib * p, float Area )
         Abc_Print( 0, "No wire model given.\n" );
         return NULL;
     }
-    // Get the actual table and reformat it for 'wire_cap' output:
-    assert( pWLoadUsed != NULL );
-    SC_LibForEachWireLoad( p, pWL, i )
-        if ( !strcmp(pWL->pName, pWLoadUsed) )
-            break;
-    if ( i == Vec_PtrSize(p->vWireLoads) )
-    {
-        Abc_Print( -1, "Cannot find wire load model \"%s\".\n", pWLoadUsed );
-        exit(1);
-    }
-//    printf( "Using wireload model \"%s\".\n", pWL->pName );
-    return pWL;
+    return Abc_SclFetchWireLoadModel( p, pWLoadUsed );
 }
 
 /**Function*************************************************************

src/map/scl/sclLib.h

@@ -71,6 +71,7 @@ struct SC_SizePars_
     int        DelayGap;
     int        TimeOut;
     int        BuffTreeEst;      // ratio for buffer tree estimation
+    int        BypassFreq;       // frequency to try bypassing
     int        fUseDept;
     int        fDumpStats;
     int        fUseWireLoads;
@@ -550,6 +551,7 @@ extern int           Abc_SclClassCellNum( SC_Cell * pClass );
 extern void          Abc_SclLinkCells( SC_Lib * p );
 extern void          Abc_SclPrintCells( SC_Lib * p, float Slew, float Gain );
 extern SC_WireLoad * Abc_SclFindWireLoadModel( SC_Lib * p, float Area );
+extern SC_WireLoad * Abc_SclFetchWireLoadModel( SC_Lib * p, char * pName );
 extern void          Abc_SclDumpGenlib( char * pFileName, SC_Lib * p, float Slew, float Gain, int nGatesMin );
 
 ABC_NAMESPACE_HEADER_END

src/map/scl/sclLoad.c

@@ -37,7 +37,7 @@ ABC_NAMESPACE_IMPL_START
 
   Description []
                
-  SideEffects []
+  SideEffects []`
 
   SeeAlso     []
 
@@ -187,6 +187,23 @@ void Abc_SclUpdateLoad( SC_Man * p, Abc_Obj_t * pObj, SC_Cell * pOld, SC_Cell *
         pLoad->fall += pPinNew->fall_cap - pPinOld->fall_cap;
     }
 }
+void Abc_SclUpdateLoadSplit( SC_Man * p, Abc_Obj_t * pBuffer, Abc_Obj_t * pFanout )
+{
+    SC_Pin * pPin;
+    SC_Pair * pLoad;
+    int iFanin = Abc_NodeFindFanin( pFanout, pBuffer );
+    assert( iFanin >= 0 );
+    assert( Abc_ObjFaninNum(pBuffer) == 1 );
+    pPin = SC_CellPin( Abc_SclObjCell(p, pFanout), iFanin );
+    // update load of the buffer
+    pLoad = Abc_SclObjLoad( p, pBuffer );
+    pLoad->rise -= pPin->rise_cap;
+    pLoad->fall -= pPin->fall_cap;
+    // update load of the fanin
+    pLoad = Abc_SclObjLoad( p, Abc_ObjFanin0(pBuffer) );
+    pLoad->rise += pPin->rise_cap;
+    pLoad->fall += pPin->fall_cap;
+}
 
 ////////////////////////////////////////////////////////////////////////
 ///                       END OF FILE                                ///

src/map/scl/sclSize.c

@@ -443,7 +443,15 @@ SC_Man * Abc_SclManStart( SC_Lib * pLib, Abc_Ntk_t * pNtk, int fUseWireLoads, in
     p->vGates = Abc_SclManFindGates( pLib, pNtk );
     Abc_SclManReadSlewAndLoad( p, pNtk );
     if ( fUseWireLoads )
+    {
+        if ( pNtk->pWLoadUsed == NULL )
+        {            
             p->pWLoadUsed = Abc_SclFindWireLoadModel( pLib, Abc_SclGetTotalArea(p) );
+            pNtk->pWLoadUsed = Abc_UtilStrsav( p->pWLoadUsed->pName );
+        }
+        else
+            p->pWLoadUsed = Abc_SclFetchWireLoadModel( pLib, pNtk->pWLoadUsed );
+    }
     Abc_SclTimeNtkRecompute( p, &p->SumArea0, &p->MaxDelay0, fDept, DUser );
     p->SumArea = p->SumArea0;
     return p;

src/map/scl/sclSize.h

@@ -50,9 +50,11 @@ struct SC_Man_
     Vec_Int_t *    vGates;        // mapping of objId into gateId
     Vec_Int_t *    vGatesBest;    // best gate sizes found so far
     Vec_Int_t *    vUpdates;      // sizing updates in this round
+    Vec_Int_t *    vUpdates2;     // sizing updates in this round
     // timing information
     SC_Pair *      pLoads;        // loads for each gate
     SC_Pair *      pLoads2;       // loads for each gate
+    SC_Pair *      pLoads3;       // loads for each gate
     SC_Pair *      pDepts;        // departures for each gate
     SC_Pair *      pTimes;        // arrivals for each gate
     SC_Pair *      pSlews;        // slews for each gate
@@ -60,6 +62,7 @@ struct SC_Man_
     SC_Pair *      pSlews2;       // slews for each gate
     float *        pSlack;        // slacks for each gatt
     float *        pInDrive;      // maximum input drive strength
+    Vec_Int_t *    vBestFans;     // best fanouts
     Vec_Flt_t *    vTimesOut;     // output arrival times
     Vec_Que_t *    vQue;          // outputs by their time
     SC_WireLoad *  pWLoadUsed;    // name of the used WireLoad model
@@ -101,6 +104,7 @@ static inline void      Abc_SclObjSetCell( SC_Man * p, Abc_Obj_t * pObj, SC_Cell
 
 static inline SC_Pair * Abc_SclObjLoad( SC_Man * p, Abc_Obj_t * pObj )              { return p->pLoads + Abc_ObjId(pObj);  }
 static inline SC_Pair * Abc_SclObjLoad2( SC_Man * p, Abc_Obj_t * pObj )             { return p->pLoads2 + Abc_ObjId(pObj); }
+static inline SC_Pair * Abc_SclObjLoad3( SC_Man * p, Abc_Obj_t * pObj )             { return p->pLoads3 + Abc_ObjId(pObj); }
 static inline SC_Pair * Abc_SclObjDept( SC_Man * p, Abc_Obj_t * pObj )              { return p->pDepts + Abc_ObjId(pObj);  }
 static inline SC_Pair * Abc_SclObjTime( SC_Man * p, Abc_Obj_t * pObj )              { return p->pTimes + Abc_ObjId(pObj);  }
 static inline SC_Pair * Abc_SclObjSlew( SC_Man * p, Abc_Obj_t * pObj )              { return p->pSlews + Abc_ObjId(pObj);  }
@@ -150,18 +154,21 @@ static inline SC_Man * Abc_SclManAlloc( SC_Lib * pLib, Abc_Ntk_t * pNtk )
     p->nObjs     = Abc_NtkObjNumMax(pNtk);
     p->pLoads    = ABC_CALLOC( SC_Pair, p->nObjs );
     p->pLoads2   = ABC_CALLOC( SC_Pair, p->nObjs );
+    p->pLoads3   = ABC_CALLOC( SC_Pair, p->nObjs );
     p->pDepts    = ABC_CALLOC( SC_Pair, p->nObjs );
     p->pTimes    = ABC_CALLOC( SC_Pair, p->nObjs );
     p->pSlews    = ABC_CALLOC( SC_Pair, p->nObjs );
     p->pTimes2   = ABC_CALLOC( SC_Pair, p->nObjs );
     p->pSlews2   = ABC_CALLOC( SC_Pair, p->nObjs );
     p->pSlack    = ABC_FALLOC( float, p->nObjs );
+    p->vBestFans = Vec_IntStart( p->nObjs );
     p->vTimesOut = Vec_FltStart( Abc_NtkCoNum(pNtk) );
     p->vQue      = Vec_QueAlloc( Abc_NtkCoNum(pNtk) );
     Vec_QueSetCosts( p->vQue, Vec_FltArrayP(p->vTimesOut) );
     for ( i = 0; i < Abc_NtkCoNum(pNtk); i++ )
         Vec_QuePush( p->vQue, i );
     p->vUpdates  = Vec_IntAlloc( 1000 );
+    p->vUpdates2 = Vec_IntAlloc( 1000 );
     // intermediate data
     p->vNode2Gain  = Vec_FltStart( p->nObjs );
     p->vNode2Gate  = Vec_IntStart( p->nObjs );
@@ -178,14 +185,17 @@ static inline void Abc_SclManFree( SC_Man * p )
     Vec_IntFreeP( &p->vNode2Gate );
     // intermediate data
     Vec_IntFreeP( &p->vUpdates );
+    Vec_IntFreeP( &p->vUpdates2 );
     Vec_IntFreeP( &p->vGatesBest );
 //    Vec_QuePrint( p->vQue );
     Vec_QueCheck( p->vQue );
     Vec_QueFreeP( &p->vQue );
     Vec_FltFreeP( &p->vTimesOut );
     Vec_IntFreeP( &p->vGates );
+    Vec_IntFreeP( &p->vBestFans );
     ABC_FREE( p->pLoads );
     ABC_FREE( p->pLoads2 );
+    ABC_FREE( p->pLoads3 );
     ABC_FREE( p->pDepts );
     ABC_FREE( p->pTimes );
     ABC_FREE( p->pSlews );
@@ -289,6 +299,23 @@ static inline void Abc_SclLoadRestore( SC_Man * p, Abc_Obj_t * pObj )
         *Abc_SclObjLoad(p, pFanin) = *Abc_SclObjLoad2(p, pFanin);
 }
 
+static inline void Abc_SclLoadStore3( SC_Man * p, Abc_Obj_t * pObj )
+{
+    Abc_Obj_t * pFanin;
+    int i;
+    *Abc_SclObjLoad3(p, pObj) = *Abc_SclObjLoad(p, pObj);
+    Abc_ObjForEachFanin( pObj, pFanin, i )
+        *Abc_SclObjLoad3(p, pFanin) = *Abc_SclObjLoad(p, pFanin);
+}
+static inline void Abc_SclLoadRestore3( SC_Man * p, Abc_Obj_t * pObj )
+{
+    Abc_Obj_t * pFanin;
+    int i;
+    *Abc_SclObjLoad(p, pObj) = *Abc_SclObjLoad3(p, pObj);
+    Abc_ObjForEachFanin( pObj, pFanin, i )
+        *Abc_SclObjLoad(p, pFanin) = *Abc_SclObjLoad3(p, pFanin);
+}
+
 /**Function*************************************************************
 
   Synopsis    []
@@ -394,6 +421,8 @@ static inline void Abc_SclDumpStats( SC_Man * p, char * pFileName, abctime Time
 
 
 /*=== sclBuffer.c ===============================================================*/
+extern int           Abc_SclIsInv( Abc_Obj_t * pObj );
+extern void          Abc_NodeInvUpdateObjFanoutPolarity( Abc_Obj_t * pObj, Abc_Obj_t * pFanout );
 extern Abc_Ntk_t *   Abc_SclUnBufferPerform( Abc_Ntk_t * pNtk, int fVerbose );
 extern Abc_Ntk_t *   Abc_SclUnBufferPhase( Abc_Ntk_t * pNtk, int fVerbose );
 extern Abc_Ntk_t *   Abc_SclBufferPhase( Abc_Ntk_t * pNtk, int fVerbose );
@@ -405,6 +434,7 @@ extern void          Abc_SclDnsizePerform( SC_Lib * pLib, Abc_Ntk_t * pNtk, SC_S
 /*=== sclLoad.c ===============================================================*/
 extern void          Abc_SclComputeLoad( SC_Man * p );
 extern void          Abc_SclUpdateLoad( SC_Man * p, Abc_Obj_t * pObj, SC_Cell * pOld, SC_Cell * pNew );
+extern void          Abc_SclUpdateLoadSplit( SC_Man * p, Abc_Obj_t * pBuffer, Abc_Obj_t * pFanout );
 /*=== sclSize.c ===============================================================*/
 extern Abc_Obj_t *   Abc_SclFindCriticalCo( SC_Man * p, int * pfRise );
 extern Abc_Obj_t *   Abc_SclFindMostCriticalFanin( SC_Man * p, int * pfRise, Abc_Obj_t * pNode );