Adding switch 'map -f' to not use large gates for high-fanout nodes (disabled by default).

src/base/abci/abc.c

@@ -14369,9 +14369,10 @@ int Abc_CommandMap( Abc_Frame_t * pAbc, int argc, char ** argv )
     int fRecovery;
     int fSweep;
     int fSwitching;
+    int fSkipFanout;
     int fVerbose;
     int c;
-    extern Abc_Ntk_t * Abc_NtkMap( Abc_Ntk_t * pNtk, double DelayTarget, double AreaMulti, double DelayMulti, float LogFan, float Slew, float Gain, int nGatesMin, int fRecovery, int fSwitching, int fVerbose );
+    extern Abc_Ntk_t * Abc_NtkMap( Abc_Ntk_t * pNtk, double DelayTarget, double AreaMulti, double DelayMulti, float LogFan, float Slew, float Gain, int nGatesMin, int fRecovery, int fSwitching, int fSkipFanout, int fVerbose );
     extern int Abc_NtkFraigSweep( Abc_Ntk_t * pNtk, int fUseInv, int fExdc, int fVerbose, int fVeryVerbose );
 
     pNtk = Abc_FrameReadNtk(pAbc);
@@ -14383,9 +14384,10 @@ int Abc_CommandMap( Abc_Frame_t * pAbc, int argc, char ** argv )
     fRecovery   = 1;
     fSweep      = 0;
     fSwitching  = 0;
+    fSkipFanout = 0;
     fVerbose    = 0;
     Extra_UtilGetoptReset();
-    while ( ( c = Extra_UtilGetopt( argc, argv, "DABFSGMarspvh" ) ) != EOF )
+    while ( ( c = Extra_UtilGetopt( argc, argv, "DABFSGMarspfvh" ) ) != EOF )
     {
         switch ( c )
         {
@@ -14474,6 +14476,9 @@ int Abc_CommandMap( Abc_Frame_t * pAbc, int argc, char ** argv )
         case 'p':
             fSwitching ^= 1;
             break;
+        case 'f':
+            fSkipFanout ^= 1;
+            break;
         case 'v':
             fVerbose ^= 1;
             break;
@@ -14510,7 +14515,7 @@ int Abc_CommandMap( Abc_Frame_t * pAbc, int argc, char ** argv )
         }
         Abc_Print( 0, "The network was strashed and balanced before mapping.\n" );
         // get the new network
-        pNtkRes = Abc_NtkMap( pNtk, DelayTarget, AreaMulti, DelayMulti, LogFan, Slew, Gain, nGatesMin, fRecovery, fSwitching, fVerbose );
+        pNtkRes = Abc_NtkMap( pNtk, DelayTarget, AreaMulti, DelayMulti, LogFan, Slew, Gain, nGatesMin, fRecovery, fSwitching, fSkipFanout, fVerbose );
         if ( pNtkRes == NULL )
         {
             Abc_NtkDelete( pNtk );
@@ -14522,7 +14527,7 @@ int Abc_CommandMap( Abc_Frame_t * pAbc, int argc, char ** argv )
     else
     {
         // get the new network
-        pNtkRes = Abc_NtkMap( pNtk, DelayTarget, AreaMulti, DelayMulti, LogFan, Slew, Gain, nGatesMin, fRecovery, fSwitching, fVerbose );
+        pNtkRes = Abc_NtkMap( pNtk, DelayTarget, AreaMulti, DelayMulti, LogFan, Slew, Gain, nGatesMin, fRecovery, fSwitching, fSkipFanout, fVerbose );
         if ( pNtkRes == NULL )
         {
             Abc_Print( -1, "Mapping has failed.\n" );
@@ -14549,7 +14554,7 @@ usage:
         sprintf(Buffer, "not used" );
     else
         sprintf(Buffer, "%.3f", DelayTarget );
-    Abc_Print( -2, "usage: map [-DABFSG float] [-M num] [-arspvh]\n" );
+    Abc_Print( -2, "usage: map [-DABFSG float] [-M num] [-arspfvh]\n" );
     Abc_Print( -2, "\t           performs standard cell mapping of the current network\n" );
     Abc_Print( -2, "\t-D float : sets the global required times [default = %s]\n", Buffer );
     Abc_Print( -2, "\t-A float : \"area multiplier\" to bias gate selection [default = %.2f]\n", AreaMulti );
@@ -14562,6 +14567,7 @@ usage:
     Abc_Print( -2, "\t-r       : toggles area recovery [default = %s]\n", fRecovery? "yes": "no" );
     Abc_Print( -2, "\t-s       : toggles sweep after mapping [default = %s]\n", fSweep? "yes": "no" );
     Abc_Print( -2, "\t-p       : optimizes power by minimizing switching [default = %s]\n", fSwitching? "yes": "no" );
+    Abc_Print( -2, "\t-f       : do not use large gates to map high-fanout nodes [default = %s]\n", fSkipFanout? "yes": "no" );
     Abc_Print( -2, "\t-v       : toggles verbose output [default = %s]\n", fVerbose? "yes": "no" );
     Abc_Print( -2, "\t-h       : print the command usage\n");
     return 1;

src/base/abci/abcMap.c

@@ -56,7 +56,7 @@ static Abc_Obj_t *  Abc_NodeFromMapSuperChoice_rec( Abc_Ntk_t * pNtkNew, Map_Sup
   SeeAlso     []
 
 ***********************************************************************/
-Abc_Ntk_t * Abc_NtkMap( Abc_Ntk_t * pNtk, double DelayTarget, double AreaMulti, double DelayMulti, float LogFan, float Slew, float Gain, int nGatesMin, int fRecovery, int fSwitching, int fVerbose )
+Abc_Ntk_t * Abc_NtkMap( Abc_Ntk_t * pNtk, double DelayTarget, double AreaMulti, double DelayMulti, float LogFan, float Slew, float Gain, int nGatesMin, int fRecovery, int fSwitching, int fSkipFanout, int fVerbose )
 {
     static int fUseMulti = 0;
     int fShowSwitching = 1;
@@ -132,6 +132,7 @@ Abc_Ntk_t * Abc_NtkMap( Abc_Ntk_t * pNtk, double DelayTarget, double AreaMulti,
         return NULL;
 clk = Abc_Clock();
     Map_ManSetSwitching( pMan, fSwitching );
+    Map_ManSetSkipFanout( pMan, fSkipFanout );
     if ( LogFan != 0 )
         Map_ManCreateNodeDelays( pMan, LogFan );
     if ( !Map_Mapping( pMan ) )

src/map/mapper/mapper.h

@@ -108,6 +108,7 @@ extern void            Map_ManSetChoiceNodeNum( Map_Man_t * p, int nChoiceNodes
 extern void            Map_ManSetChoiceNum( Map_Man_t * p, int nChoices );
 extern void            Map_ManSetVerbose( Map_Man_t * p, int fVerbose );
 extern void            Map_ManSetSwitching( Map_Man_t * p, int fSwitching );
+extern void            Map_ManSetSkipFanout( Map_Man_t * p, int fSkipFanout );
 
 extern Map_Man_t *     Map_NodeReadMan( Map_Node_t * p );
 extern char *          Map_NodeReadData( Map_Node_t * p, int fPhase );

src/map/mapper/mapperCreate.c

@@ -73,6 +73,7 @@ void            Map_ManSetChoiceNodeNum( Map_Man_t * p, int nChoiceNodes ) { p->
 void            Map_ManSetChoiceNum( Map_Man_t * p, int nChoices )         { p->nChoices = nChoices;     }   
 void            Map_ManSetVerbose( Map_Man_t * p, int fVerbose )           { p->fVerbose = fVerbose;     }   
 void            Map_ManSetSwitching( Map_Man_t * p, int fSwitching )       { p->fSwitching = fSwitching; }   
+void            Map_ManSetSkipFanout( Map_Man_t * p, int fSkipFanout )     { p->fSkipFanout = fSkipFanout; }   
 
 /**Function*************************************************************
 

src/map/mapper/mapperInt.h

@@ -120,7 +120,8 @@ struct Map_ManStruct_t_
     int                 fObeyFanoutLimits;// Should mapper try to obey fanout limits or not
     float               DelayTarget;   // the required times set by the user
     int                 nTravIds;      // the traversal counter
-    int                 fSwitching;    // Should mapper try to obey fanout limits or not
+    int                 fSwitching;    // use switching activity
+    int                 fSkipFanout;   // skip large gates when mapping high-fanout nodes
 
     // the supergate library
     Map_SuperLib_t *    pSuperLib;     // the current supergate library

src/map/mapper/mapperMatch.c

@@ -288,7 +288,7 @@ int Map_MatchNodePhase( Map_Man_t * p, Map_Node_t * pNode, int fPhase )
     for ( pCut = pNode->pCuts->pNext; pCut; pCut = pCut->pNext )
     {
         // limit gate sizes based on fanout count
-        if ( (pNode->nRefs > 3 && pCut->nLeaves > 2) || (pNode->nRefs > 1 && pCut->nLeaves > 3) )
+        if ( p->fSkipFanout && (pNode->nRefs > 3 && pCut->nLeaves > 2) || (pNode->nRefs > 1 && pCut->nLeaves > 3) )
             continue;
         pMatch = pCut->M + fPhase;
         if ( pMatch->pSupers == NULL )