Logic restruturing after mapping.

src/base/acb/acbPush.c

+/**CFile****************************************************************
+
+  FileName    [acbPush.c]
+
+  SystemName  [ABC: Logic synthesis and verification system.]
+
+  PackageName [Hierarchical word-level netlist.]
+
+  Synopsis    [Implementation of logic pushing.]
+
+  Author      [Alan Mishchenko]
+  
+  Affiliation [UC Berkeley]
+
+  Date        [Ver. 1.0. Started - July 21, 2015.]
+
+  Revision    [$Id: acbPush.c,v 1.00 2014/11/29 00:00:00 alanmi Exp $]
+
+***********************************************************************/
+
+#include "acb.h"
+#include "misc/util/utilTruth.h"
+
+ABC_NAMESPACE_IMPL_START
+
+////////////////////////////////////////////////////////////////////////
+///                        DECLARATIONS                              ///
+////////////////////////////////////////////////////////////////////////
+
+////////////////////////////////////////////////////////////////////////
+///                     FUNCTION DEFINITIONS                         ///
+////////////////////////////////////////////////////////////////////////
+
+/**Function*************************************************************
+
+  Synopsis    [Check if the node can have its logic pushed.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int Acb_ObjCheckFaninDsd( Acb_Ntk_t * p, int iObj, int iFanIndex )
+{
+    int k, iFanin, * pFanins;
+    Acb_ObjForEachFaninFast( p, iObj, pFanins, iFanin, k )
+        if ( Abc_TtCheckDsdAnd(Acb_ObjTruth(p, iObj), iFanIndex, k, NULL) >= 0 )
+            return 1;
+    return 0;
+}
+int Acb_ObjCountFaninAbsorb( Acb_Ntk_t * p, int iObj, int iFanin, int iFanIndex, int nLutSize )
+{
+    if ( Acb_ObjSetTravIdCur(p, iFanin) )
+        return 0;
+    if ( Acb_ObjIsCi(p, iFanin) )
+        return 0;
+    if ( Acb_ObjFanoutNum(p, iFanin) > 1 )
+        return 0;
+    if ( !Acb_ObjCheckFaninDsd(p, iObj, iFanIndex) ) 
+        return 0;
+    if ( Acb_ObjFaninNum(p, iFanin) == nLutSize )
+        return 0;
+    return 1;
+}
+int Acb_NtkObjPushEstimate( Acb_Ntk_t * p, int iObj, int nLutSize )
+{
+    int k, iFanin, * pFanins;
+    int Count = Acb_ObjFaninNum(p, iObj);
+    Acb_NtkIncTravId( p );
+    Acb_ObjForEachFaninFast( p, iObj, pFanins, iFanin, k )
+    {
+        Count -= Acb_ObjCountFaninAbsorb( p, iObj, iFanin, k, nLutSize );
+        if ( Count <= 0 )
+            return 1;
+    }
+    if ( Acb_ObjFanoutNum(p, iObj) > 1 )
+        return 0;
+    Acb_ObjForEachFaninFast( p, iObj, pFanins, iFanin, k )
+        if ( Abc_TtCheckOutAnd(Acb_ObjTruth(p, iObj), k, NULL) )
+            break;
+    if ( k == Acb_ObjFaninNum(p, iFanin) )
+        return 0;
+    iFanin = Vec_IntEntry( Acb_ObjFanout(p, iObj), 0 );
+    if ( Acb_ObjFaninNum(p, iFanin) == nLutSize )
+        return 0;
+    return 1;
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Acb_NtkPushLogic( Acb_Ntk_t * p, int nLutSize, int fVerbose )
+{
+    //Vec_Bit_t * vVisited = Vec_BitStart( Acb_NtkObjNumMax(p) );
+    int n = 0, iObj, nNodes = 0;
+    Acb_NtkCreateFanout( p );  // fanout data structure
+    for ( n = 2; n <= nLutSize; n++ )
+        Acb_NtkForEachNode( p, iObj )
+        {
+            if ( !Acb_NtkObjPushEstimate(p, iObj, nLutSize) )
+                continue;
+            nNodes++;
+        }
+    printf( "Performed optimization at %d nodes.\n", nNodes );
+    //Vec_BitFree( vVisited );
+}
+
+////////////////////////////////////////////////////////////////////////
+///                       END OF FILE                                ///
+////////////////////////////////////////////////////////////////////////
+
+
+ABC_NAMESPACE_IMPL_END
+