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Diffstat (limited to 'src/aig/ivy/ivyRwr.c')
| -rw-r--r-- | src/aig/ivy/ivyRwr.c | 609 |
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 /// +//////////////////////////////////////////////////////////////////////// + + |