Version abc80130_2

1 files changed, 609 insertions, 0 deletions

diff --git a/src/aig/ivy/ivyRwr.c b/src/aig/ivy/ivyRwr.c
new file mode 100644
index 00000000..3f8720ba
--- /dev/null
+++ b/src/aig/ivy/ivyRwr.c
@@ -0,0 +1,609 @@
+/**CFile****************************************************************
+
+  FileName    [ivyRwt.c]
+
+  SystemName  [ABC: Logic synthesis and verification system.]
+
+  PackageName [And-Inverter Graph package.]
+
+  Synopsis    [Rewriting based on precomputation.]
+
+  Author      [Alan Mishchenko]
+  
+  Affiliation [UC Berkeley]
+
+  Date        [Ver. 1.0. Started - May 11, 2006.]
+
+  Revision    [$Id: ivyRwt.c,v 1.00 2006/05/11 00:00:00 alanmi Exp $]
+
+***********************************************************************/
+
+#include "ivy.h"
+#include "deco.h"
+#include "rwt.h"
+
+////////////////////////////////////////////////////////////////////////
+///                        DECLARATIONS                              ///
+////////////////////////////////////////////////////////////////////////
+
+static unsigned Ivy_NodeGetTruth( Ivy_Obj_t * pObj, int * pNums, int nNums );
+static int Ivy_NodeRewrite( Ivy_Man_t * pMan, Rwt_Man_t * p, Ivy_Obj_t * pNode, int fUpdateLevel, int fUseZeroCost );
+static Dec_Graph_t * Rwt_CutEvaluate( Ivy_Man_t * pMan, Rwt_Man_t * p, Ivy_Obj_t * pRoot, 
+    Vec_Ptr_t * vFaninsCur, int nNodesSaved, int LevelMax, int * pGainBest, unsigned uTruth );
+
+static int Ivy_GraphToNetworkCount( Ivy_Man_t * p, Ivy_Obj_t * pRoot, Dec_Graph_t * pGraph, int NodeMax, int LevelMax );
+static void Ivy_GraphUpdateNetwork( Ivy_Man_t * p, Ivy_Obj_t * pRoot, Dec_Graph_t * pGraph, int fUpdateLevel, int nGain );
+
+////////////////////////////////////////////////////////////////////////
+///                     FUNCTION DEFINITIONS                         ///
+////////////////////////////////////////////////////////////////////////
+
+/**Function*************************************************************
+
+  Synopsis    [Performs incremental rewriting of the AIG.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int Ivy_ManRewritePre( Ivy_Man_t * p, int fUpdateLevel, int fUseZeroCost, int fVerbose )
+{
+    Rwt_Man_t * pManRwt;
+    Ivy_Obj_t * pNode;
+    int i, nNodes, nGain;
+    int clk, clkStart = clock();
+    // start the rewriting manager
+    pManRwt = Rwt_ManStart( 0 );
+    p->pData = pManRwt;
+    if ( pManRwt == NULL )
+        return 0; 
+    // create fanouts
+    if ( fUpdateLevel && p->fFanout == 0 )
+        Ivy_ManStartFanout( p );
+    // compute the reverse levels if level update is requested
+    if ( fUpdateLevel )
+        Ivy_ManRequiredLevels( p );
+    // set the number of levels
+//    p->nLevelMax = Ivy_ManLevels( p );
+    // resynthesize each node once
+    nNodes = Ivy_ManObjIdMax(p);
+    Ivy_ManForEachNode( p, pNode, i )
+    {
+        // fix the fanin buffer problem
+        Ivy_NodeFixBufferFanins( p, pNode, 1 );
+        if ( Ivy_ObjIsBuf(pNode) )
+            continue;
+        // stop if all nodes have been tried once
+        if ( i > nNodes )
+            break;
+        // for each cut, try to resynthesize it
+        nGain = Ivy_NodeRewrite( p, pManRwt, pNode, fUpdateLevel, fUseZeroCost );
+        if ( nGain > 0 || nGain == 0 && fUseZeroCost )
+        {
+            Dec_Graph_t * pGraph = Rwt_ManReadDecs(pManRwt);
+            int fCompl           = Rwt_ManReadCompl(pManRwt);
+/*
+            {
+                Ivy_Obj_t * pObj;
+                int i;
+                printf( "USING: (" );
+                Vec_PtrForEachEntry( Rwt_ManReadLeaves(pManRwt), pObj, i )
+                    printf( "%d ", Ivy_ObjFanoutNum(Ivy_Regular(pObj)) );
+                printf( ")   Gain = %d.\n", nGain );
+            }
+            if ( nGain > 0 )
+            { // print stats on the MFFC
+                extern void Ivy_NodeMffsConeSuppPrint( Ivy_Obj_t * pNode );
+                printf( "Node %6d : Gain = %4d  ", pNode->Id, nGain );
+                Ivy_NodeMffsConeSuppPrint( pNode );
+            }
+*/
+            // complement the FF if needed
+clk = clock();
+            if ( fCompl ) Dec_GraphComplement( pGraph );
+            Ivy_GraphUpdateNetwork( p, pNode, pGraph, fUpdateLevel, nGain );
+            if ( fCompl ) Dec_GraphComplement( pGraph );
+Rwt_ManAddTimeUpdate( pManRwt, clock() - clk );
+        }
+    }
+Rwt_ManAddTimeTotal( pManRwt, clock() - clkStart );
+    // print stats
+    if ( fVerbose )
+        Rwt_ManPrintStats( pManRwt );
+    // delete the managers
+    Rwt_ManStop( pManRwt );
+    p->pData = NULL;
+    // fix the levels
+    if ( fUpdateLevel )
+        Vec_IntFree( p->vRequired ), p->vRequired = NULL;
+    else
+        Ivy_ManResetLevels( p );
+    // check
+    if ( i = Ivy_ManCleanup(p) )
+        printf( "Cleanup after rewriting removed %d dangling nodes.\n", i );
+    if ( !Ivy_ManCheck(p) )
+        printf( "Ivy_ManRewritePre(): The check has failed.\n" );
+    return 1;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Performs rewriting for one node.]
+
+  Description [This procedure considers all the cuts computed for the node
+  and tries to rewrite each of them using the "forest" of different AIG
+  structures precomputed and stored in the RWR manager. 
+  Determines the best rewriting and computes the gain in the number of AIG
+  nodes in the final network. In the end, p->vFanins contains information 
+  about the best cut that can be used for rewriting, while p->pGraph gives 
+  the decomposition dag (represented using decomposition graph data structure).
+  Returns gain in the number of nodes or -1 if node cannot be rewritten.]
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int Ivy_NodeRewrite( Ivy_Man_t * pMan, Rwt_Man_t * p, Ivy_Obj_t * pNode, int fUpdateLevel, int fUseZeroCost )
+{
+    int fVeryVerbose = 0;
+    Dec_Graph_t * pGraph;
+    Ivy_Store_t * pStore;
+    Ivy_Cut_t * pCut;
+    Ivy_Obj_t * pFanin;
+    unsigned uPhase, uTruthBest, uTruth;
+    char * pPerm;
+    int Required, nNodesSaved, nNodesSaveCur;
+    int i, c, GainCur, GainBest = -1;
+    int clk, clk2;
+
+    p->nNodesConsidered++;
+    // get the required times
+    Required = fUpdateLevel? Vec_IntEntry( pMan->vRequired, pNode->Id ) : 1000000;
+    // get the node's cuts
+clk = clock();
+    pStore = Ivy_NodeFindCutsAll( pMan, pNode, 5 );
+p->timeCut += clock() - clk;
+
+    // go through the cuts
+clk = clock();
+    for ( c = 1; c < pStore->nCuts; c++ )
+    {
+        pCut = pStore->pCuts + c;
+        // consider only 4-input cuts
+        if ( pCut->nSize != 4 )
+            continue;
+        // skip the cuts with buffers
+        for ( i = 0; i < (int)pCut->nSize; i++ )
+            if ( Ivy_ObjIsBuf( Ivy_ManObj(pMan, pCut->pArray[i]) ) )
+                break;
+        if ( i != pCut->nSize )
+        {
+            p->nCutsBad++;
+            continue;
+        }
+        p->nCutsGood++;
+        // get the fanin permutation
+clk2 = clock();
+        uTruth = 0xFFFF & Ivy_NodeGetTruth( pNode, pCut->pArray, pCut->nSize );  // truth table
+p->timeTruth += clock() - clk2;
+        pPerm = p->pPerms4[ p->pPerms[uTruth] ];
+        uPhase = p->pPhases[uTruth];
+        // collect fanins with the corresponding permutation/phase
+        Vec_PtrClear( p->vFaninsCur );
+        Vec_PtrFill( p->vFaninsCur, (int)pCut->nSize, 0 );
+        for ( i = 0; i < (int)pCut->nSize; i++ )
+        {
+            pFanin = Ivy_ManObj( pMan, pCut->pArray[pPerm[i]] );
+            assert( Ivy_ObjIsNode(pFanin) || Ivy_ObjIsCi(pFanin) );
+            pFanin = Ivy_NotCond(pFanin, ((uPhase & (1<<i)) > 0) );
+            Vec_PtrWriteEntry( p->vFaninsCur, i, pFanin );
+        }
+clk2 = clock();
+/*
+        printf( "Considering: (" );
+        Vec_PtrForEachEntry( p->vFaninsCur, pFanin, i )
+            printf( "%d ", Ivy_ObjFanoutNum(Ivy_Regular(pFanin)) );
+        printf( ")\n" );
+*/
+        // mark the fanin boundary 
+        Vec_PtrForEachEntry( p->vFaninsCur, pFanin, i )
+            Ivy_ObjRefsInc( Ivy_Regular(pFanin) );
+        // label MFFC with current ID
+        Ivy_ManIncrementTravId( pMan );
+        nNodesSaved = Ivy_ObjMffcLabel( pMan, pNode );
+        // unmark the fanin boundary
+        Vec_PtrForEachEntry( p->vFaninsCur, pFanin, i )
+            Ivy_ObjRefsDec( Ivy_Regular(pFanin) );
+p->timeMffc += clock() - clk2;
+
+        // evaluate the cut
+clk2 = clock();
+        pGraph = Rwt_CutEvaluate( pMan, p, pNode, p->vFaninsCur, nNodesSaved, Required, &GainCur, uTruth );
+p->timeEval += clock() - clk2;
+
+        // check if the cut is better than the current best one
+        if ( pGraph != NULL && GainBest < GainCur )
+        {
+            // save this form
+            nNodesSaveCur = nNodesSaved;
+            GainBest  = GainCur;
+            p->pGraph  = pGraph;
+            p->fCompl = ((uPhase & (1<<4)) > 0);
+            uTruthBest = uTruth;
+            // collect fanins in the
+            Vec_PtrClear( p->vFanins );
+            Vec_PtrForEachEntry( p->vFaninsCur, pFanin, i )
+                Vec_PtrPush( p->vFanins, pFanin );
+        }
+    }
+p->timeRes += clock() - clk;
+
+    if ( GainBest == -1 )
+        return -1;
+
+//    printf( "%d", nNodesSaveCur - GainBest );
+/*
+    if ( GainBest > 0 )
+    {
+        if ( Rwt_CutIsintean( pNode, p->vFanins ) )
+            printf( "b" );
+        else
+        {
+            printf( "Node %d : ", pNode->Id );
+            Vec_PtrForEachEntry( p->vFanins, pFanin, i )
+                printf( "%d ", Ivy_Regular(pFanin)->Id );
+            printf( "a" );
+        }
+    }
+*/
+/*
+    if ( GainBest > 0 )
+        if ( p->fCompl )
+            printf( "c" );
+        else
+            printf( "." );
+*/
+
+    // copy the leaves
+    Vec_PtrForEachEntry( p->vFanins, pFanin, i )
+        Dec_GraphNode(p->pGraph, i)->pFunc = pFanin;
+
+    p->nScores[p->pMap[uTruthBest]]++;
+    p->nNodesGained += GainBest;
+    if ( fUseZeroCost || GainBest > 0 )
+        p->nNodesRewritten++;
+
+    // report the progress
+    if ( fVeryVerbose && GainBest > 0 )
+    {
+        printf( "Node %6d :   ", Ivy_ObjId(pNode) );
+        printf( "Fanins = %d. ", p->vFanins->nSize );
+        printf( "Save = %d.  ", nNodesSaveCur );
+        printf( "Add = %d.  ",  nNodesSaveCur-GainBest );
+        printf( "GAIN = %d.  ", GainBest );
+        printf( "Cone = %d.  ", p->pGraph? Dec_GraphNodeNum(p->pGraph) : 0 );
+        printf( "Class = %d.  ", p->pMap[uTruthBest] );
+        printf( "\n" );
+    }
+    return GainBest;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Computes the truth table.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+unsigned Ivy_NodeGetTruth_rec( Ivy_Obj_t * pObj, int * pNums, int nNums )
+{
+    static unsigned uMasks[5] = { 0xAAAAAAAA, 0xCCCCCCCC, 0xF0F0F0F0, 0xFF00FF00, 0xFFFF0000 };
+    unsigned uTruth0, uTruth1;
+    int i;
+    for ( i = 0; i < nNums; i++ )
+        if ( pObj->Id == pNums[i] )
+            return uMasks[i];
+    assert( Ivy_ObjIsNode(pObj) || Ivy_ObjIsBuf(pObj) );
+    uTruth0 = Ivy_NodeGetTruth_rec( Ivy_ObjFanin0(pObj), pNums, nNums );
+    if ( Ivy_ObjFaninC0(pObj) )
+        uTruth0 = ~uTruth0;
+    if ( Ivy_ObjIsBuf(pObj) )
+        return uTruth0;
+    uTruth1 = Ivy_NodeGetTruth_rec( Ivy_ObjFanin1(pObj), pNums, nNums );
+    if ( Ivy_ObjFaninC1(pObj) )
+        uTruth1 = ~uTruth1;
+    return uTruth0 & uTruth1;
+}
+
+
+/**Function*************************************************************
+
+  Synopsis    [Computes the truth table.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+unsigned Ivy_NodeGetTruth( Ivy_Obj_t * pObj, int * pNums, int nNums )
+{
+    assert( nNums < 6 );
+    return Ivy_NodeGetTruth_rec( pObj, pNums, nNums );
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Evaluates the cut.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+Dec_Graph_t * Rwt_CutEvaluate( Ivy_Man_t * pMan, Rwt_Man_t * p, Ivy_Obj_t * pRoot, Vec_Ptr_t * vFaninsCur, int nNodesSaved, int LevelMax, int * pGainBest, unsigned uTruth )
+{
+    Vec_Ptr_t * vSubgraphs;
+    Dec_Graph_t * pGraphBest, * pGraphCur;
+    Rwt_Node_t * pNode, * pFanin;
+    int nNodesAdded, GainBest, i, k;
+    // find the matching class of subgraphs
+    vSubgraphs = Vec_VecEntry( p->vClasses, p->pMap[uTruth] );
+    p->nSubgraphs += vSubgraphs->nSize;
+    // determine the best subgraph
+    GainBest = -1;
+    Vec_PtrForEachEntry( vSubgraphs, pNode, i )
+    {
+        // get the current graph
+        pGraphCur = (Dec_Graph_t *)pNode->pNext;
+        // copy the leaves
+        Vec_PtrForEachEntry( vFaninsCur, pFanin, k )
+            Dec_GraphNode(pGraphCur, k)->pFunc = pFanin;
+        // detect how many unlabeled nodes will be reused
+        nNodesAdded = Ivy_GraphToNetworkCount( pMan, pRoot, pGraphCur, nNodesSaved, LevelMax );
+        if ( nNodesAdded == -1 )
+            continue;
+        assert( nNodesSaved >= nNodesAdded );
+        // count the gain at this node
+        if ( GainBest < nNodesSaved - nNodesAdded )
+        {
+            GainBest   = nNodesSaved - nNodesAdded;
+            pGraphBest = pGraphCur;
+        }
+    }
+    if ( GainBest == -1 )
+        return NULL;
+    *pGainBest = GainBest;
+    return pGraphBest;
+}
+
+
+/**Function*************************************************************
+
+  Synopsis    [Counts the number of new nodes added when using this graph.]
+
+  Description [AIG nodes for the fanins should be assigned to pNode->pFunc 
+  of the leaves of the graph before calling this procedure. 
+  Returns -1 if the number of nodes and levels exceeded the given limit or 
+  the number of levels exceeded the maximum allowed level.]
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int Ivy_GraphToNetworkCount( Ivy_Man_t * p, Ivy_Obj_t * pRoot, Dec_Graph_t * pGraph, int NodeMax, int LevelMax )
+{
+    Dec_Node_t * pNode, * pNode0, * pNode1;
+    Ivy_Obj_t * pAnd, * pAnd0, * pAnd1;
+    int i, Counter, LevelNew, LevelOld;
+    // check for constant function or a literal
+    if ( Dec_GraphIsConst(pGraph) || Dec_GraphIsVar(pGraph) )
+        return 0;
+    // set the levels of the leaves
+    Dec_GraphForEachLeaf( pGraph, pNode, i )
+        pNode->Level = Ivy_Regular(pNode->pFunc)->Level;
+    // compute the AIG size after adding the internal nodes
+    Counter = 0;
+    Dec_GraphForEachNode( pGraph, pNode, i )
+    {
+        // get the children of this node
+        pNode0 = Dec_GraphNode( pGraph, pNode->eEdge0.Node );
+        pNode1 = Dec_GraphNode( pGraph, pNode->eEdge1.Node );
+        // get the AIG nodes corresponding to the children 
+        pAnd0 = pNode0->pFunc; 
+        pAnd1 = pNode1->pFunc; 
+        if ( pAnd0 && pAnd1 )
+        {
+            // if they are both present, find the resulting node
+            pAnd0 = Ivy_NotCond( pAnd0, pNode->eEdge0.fCompl );
+            pAnd1 = Ivy_NotCond( pAnd1, pNode->eEdge1.fCompl );
+            pAnd  = Ivy_TableLookup( p, Ivy_ObjCreateGhost(p, pAnd0, pAnd1, IVY_AND, IVY_INIT_NONE) );
+            // return -1 if the node is the same as the original root
+            if ( Ivy_Regular(pAnd) == pRoot )
+                return -1;
+        }
+        else
+            pAnd = NULL;
+        // count the number of added nodes
+        if ( pAnd == NULL || Ivy_ObjIsTravIdCurrent(p, Ivy_Regular(pAnd)) )
+        {
+            if ( ++Counter > NodeMax )
+                return -1;
+        }
+        // count the number of new levels
+        LevelNew = 1 + RWT_MAX( pNode0->Level, pNode1->Level );
+        if ( pAnd )
+        {
+            if ( Ivy_Regular(pAnd) == p->pConst1 )
+                LevelNew = 0;
+            else if ( Ivy_Regular(pAnd) == Ivy_Regular(pAnd0) )
+                LevelNew = (int)Ivy_Regular(pAnd0)->Level;
+            else if ( Ivy_Regular(pAnd) == Ivy_Regular(pAnd1) )
+                LevelNew = (int)Ivy_Regular(pAnd1)->Level;
+            LevelOld = (int)Ivy_Regular(pAnd)->Level;
+//            assert( LevelNew == LevelOld );
+        }
+        if ( LevelNew > LevelMax )
+            return -1;
+        pNode->pFunc = pAnd;
+        pNode->Level = LevelNew;
+    }
+    return Counter;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Transforms the decomposition graph into the AIG.]
+
+  Description [AIG nodes for the fanins should be assigned to pNode->pFunc
+  of the leaves of the graph before calling this procedure.]
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+Ivy_Obj_t * Ivy_GraphToNetwork( Ivy_Man_t * p, Dec_Graph_t * pGraph )
+{
+    Ivy_Obj_t * pAnd0, * pAnd1;
+    Dec_Node_t * pNode;
+    int i;
+    // check for constant function
+    if ( Dec_GraphIsConst(pGraph) )
+        return Ivy_NotCond( Ivy_ManConst1(p), Dec_GraphIsComplement(pGraph) );
+    // check for a literal
+    if ( Dec_GraphIsVar(pGraph) )
+        return Ivy_NotCond( Dec_GraphVar(pGraph)->pFunc, Dec_GraphIsComplement(pGraph) );
+    // build the AIG nodes corresponding to the AND gates of the graph
+    Dec_GraphForEachNode( pGraph, pNode, i )
+    {
+        pAnd0 = Ivy_NotCond( Dec_GraphNode(pGraph, pNode->eEdge0.Node)->pFunc, pNode->eEdge0.fCompl ); 
+        pAnd1 = Ivy_NotCond( Dec_GraphNode(pGraph, pNode->eEdge1.Node)->pFunc, pNode->eEdge1.fCompl ); 
+        pNode->pFunc = Ivy_And( p, pAnd0, pAnd1 );
+    }
+    // complement the result if necessary
+    return Ivy_NotCond( pNode->pFunc, Dec_GraphIsComplement(pGraph) );
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Replaces MFFC of the node by the new factored form.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Ivy_GraphUpdateNetwork( Ivy_Man_t * p, Ivy_Obj_t * pRoot, Dec_Graph_t * pGraph, int fUpdateLevel, int nGain )
+{
+    Ivy_Obj_t * pRootNew;
+    int nNodesNew, nNodesOld, Required;
+    Required = fUpdateLevel? Vec_IntEntry( p->vRequired, pRoot->Id ) : 1000000;
+    nNodesOld = Ivy_ManNodeNum(p);
+    // create the new structure of nodes
+    pRootNew = Ivy_GraphToNetwork( p, pGraph );
+    assert( (int)Ivy_Regular(pRootNew)->Level <= Required );
+//    if ( Ivy_Regular(pRootNew)->Level == Required )
+//        printf( "Difference %d.\n", Ivy_Regular(pRootNew)->Level - Required );
+    // remove the old nodes
+//    Ivy_AigReplace( pMan->pManFunc, pRoot, pRootNew, fUpdateLevel );
+/*
+    if ( Ivy_IsComplement(pRootNew) )
+        printf( "c" );
+    else
+        printf( "d" );
+    if ( Ivy_ObjRefs(Ivy_Regular(pRootNew)) > 0 )
+        printf( "%d", Ivy_ObjRefs(Ivy_Regular(pRootNew)) );
+    printf( " " );
+*/
+    Ivy_ObjReplace( p, pRoot, pRootNew, 1, 0, 1 );
+    // compare the gains
+    nNodesNew = Ivy_ManNodeNum(p);
+    assert( nGain <= nNodesOld - nNodesNew );
+    // propagate the buffer
+    Ivy_ManPropagateBuffers( p, 1 );
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Replaces MFFC of the node by the new factored form.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Ivy_GraphUpdateNetwork3( Ivy_Man_t * p, Ivy_Obj_t * pRoot, Dec_Graph_t * pGraph, int fUpdateLevel, int nGain )
+{
+    Ivy_Obj_t * pRootNew, * pFanin;
+    int nNodesNew, nNodesOld, i, nRefsOld;
+    nNodesOld = Ivy_ManNodeNum(p);
+
+//printf( "Before = %d. ", Ivy_ManNodeNum(p) );
+    // mark the cut
+    Vec_PtrForEachEntry( ((Rwt_Man_t *)p->pData)->vFanins, pFanin, i )
+        Ivy_ObjRefsInc( Ivy_Regular(pFanin) );
+    // deref the old cone
+    nRefsOld = pRoot->nRefs;  
+    pRoot->nRefs = 0;
+    Ivy_ObjDelete_rec( p, pRoot, 0 );
+    pRoot->nRefs = nRefsOld;
+    // unmark the cut
+    Vec_PtrForEachEntry( ((Rwt_Man_t *)p->pData)->vFanins, pFanin, i )
+        Ivy_ObjRefsDec( Ivy_Regular(pFanin) );
+//printf( "Deref = %d. ", Ivy_ManNodeNum(p) );
+ 
+    // create the new structure of nodes
+    pRootNew = Ivy_GraphToNetwork( p, pGraph );
+//printf( "Create = %d. ", Ivy_ManNodeNum(p) );
+    // remove the old nodes
+//    Ivy_AigReplace( pMan->pManFunc, pRoot, pRootNew, fUpdateLevel );
+/*
+    if ( Ivy_IsComplement(pRootNew) )
+        printf( "c" );
+    else
+        printf( "d" );
+    if ( Ivy_ObjRefs(Ivy_Regular(pRootNew)) > 0 )
+        printf( "%d", Ivy_ObjRefs(Ivy_Regular(pRootNew)) );
+    printf( " " );
+*/
+    Ivy_ObjReplace( p, pRoot, pRootNew, 0, 0, 1 );
+//printf( "Replace = %d. ", Ivy_ManNodeNum(p) );
+
+    // delete remaining dangling nodes
+    Vec_PtrForEachEntry( ((Rwt_Man_t *)p->pData)->vFanins, pFanin, i )
+    {
+        pFanin = Ivy_Regular(pFanin);
+        if ( !Ivy_ObjIsNone(pFanin) && Ivy_ObjRefs(pFanin) == 0 )
+            Ivy_ObjDelete_rec( p, pFanin, 1 );
+    }
+//printf( "Deref = %d. ", Ivy_ManNodeNum(p) );
+//printf( "\n" );
+
+    // compare the gains
+    nNodesNew = Ivy_ManNodeNum(p);
+    assert( nGain <= nNodesOld - nNodesNew );
+}
+
+
+////////////////////////////////////////////////////////////////////////
+///                       END OF FILE                                ///
+////////////////////////////////////////////////////////////////////////
+
+