/**CFile**************************************************************** FileName [abcRefactor.c] SystemName [ABC: Logic synthesis and verification system.] PackageName [Network and node package.] Synopsis [Resynthesis based on collapsing and refactoring.] Author [Alan Mishchenko] Affiliation [UC Berkeley] Date [Ver. 1.0. Started - June 20, 2005.] Revision [$Id: abcRefactor.c,v 1.00 2005/06/20 00:00:00 alanmi Exp $] ***********************************************************************/ #include "base/abc/abc.h" #include "bool/dec/dec.h" #include "bool/kit/kit.h" ABC_NAMESPACE_IMPL_START //////////////////////////////////////////////////////////////////////// /// DECLARATIONS /// //////////////////////////////////////////////////////////////////////// typedef struct Abc_ManRef_t_ Abc_ManRef_t; struct Abc_ManRef_t_ { // user specified parameters int nNodeSizeMax; // the limit on the size of the supernode int nConeSizeMax; // the limit on the size of the containing cone int fVerbose; // the verbosity flag // internal data structures Vec_Ptr_t * vVars; // truth tables Vec_Ptr_t * vFuncs; // functions Vec_Int_t * vMemory; // memory Vec_Str_t * vCube; // temporary Vec_Int_t * vForm; // temporary Vec_Ptr_t * vVisited; // temporary Vec_Ptr_t * vLeaves; // temporary // node statistics int nLastGain; int nNodesConsidered; int nNodesRefactored; int nNodesGained; int nNodesBeg; int nNodesEnd; // runtime statistics abctime timeCut; abctime timeTru; abctime timeDcs; abctime timeSop; abctime timeFact; abctime timeEval; abctime timeRes; abctime timeNtk; abctime timeTotal; }; //////////////////////////////////////////////////////////////////////// /// FUNCTION DEFINITIONS /// //////////////////////////////////////////////////////////////////////// /**Function************************************************************* Synopsis [Returns function of the cone.] Description [] SideEffects [] SeeAlso [] ***********************************************************************/ word * Abc_NodeConeTruth( Vec_Ptr_t * vVars, Vec_Ptr_t * vFuncs, int nWordsMax, Abc_Obj_t * pRoot, Vec_Ptr_t * vLeaves, Vec_Ptr_t * vVisited ) { Abc_Obj_t * pNode; word * pTruth0, * pTruth1, * pTruth = NULL; int i, k, nWords = Abc_Truth6WordNum( Vec_PtrSize(vLeaves) ); // get nodes in the cut without fanins in the DFS order Abc_NodeConeCollect( &pRoot, 1, vLeaves, vVisited, 0 ); // set elementary functions Vec_PtrForEachEntry( Abc_Obj_t *, vLeaves, pNode, i ) pNode->pCopy = (Abc_Obj_t *)Vec_PtrEntry( vVars, i ); // prepare functions for ( i = Vec_PtrSize(vFuncs); i < Vec_PtrSize(vVisited); i++ ) Vec_PtrPush( vFuncs, ABC_ALLOC(word, nWordsMax) ); // compute functions for the collected nodes Vec_PtrForEachEntry( Abc_Obj_t *, vVisited, pNode, i ) { assert( !Abc_ObjIsPi(pNode) ); pTruth0 = (word *)Abc_ObjFanin0(pNode)->pCopy; pTruth1 = (word *)Abc_ObjFanin1(pNode)->pCopy; pTruth = (word *)Vec_PtrEntry( vFuncs, i ); if ( Abc_ObjFaninC0(pNode) ) { if ( Abc_ObjFaninC1(pNode) ) for ( k = 0; k < nWords; k++ ) pTruth[k] = ~pTruth0[k] & ~pTruth1[k]; else for ( k = 0; k < nWords; k++ ) pTruth[k] = ~pTruth0[k] & pTruth1[k]; } else { if ( Abc_ObjFaninC1(pNode) ) for ( k = 0; k < nWords; k++ ) pTruth[k] = pTruth0[k] & ~pTruth1[k]; else for ( k = 0; k < nWords; k++ ) pTruth[k] = pTruth0[k] & pTruth1[k]; } pNode->pCopy = (Abc_Obj_t *)pTruth; } return pTruth; } int Abc_NodeConeIsConst0( word * pTruth, int nVars ) { int k, nWords = Abc_Truth6WordNum( nVars ); for ( k = 0; k < nWords; k++ ) if ( pTruth[k] ) return 0; return 1; } int Abc_NodeConeIsConst1( word * pTruth, int nVars ) { int k, nWords = Abc_Truth6WordNum( nVars ); for ( k = 0; k < nWords; k++ ) if ( ~pTruth[k] ) return 0; return 1; } /**Function************************************************************* Synopsis [Resynthesizes the node using refactoring.] Description [] SideEffects [] SeeAlso [] ***********************************************************************/ Dec_Graph_t * Abc_NodeRefactor( Abc_ManRef_t * p, Abc_Obj_t * pNode, Vec_Ptr_t * vFanins, int fUpdateLevel, int fUseZeros, int fUseDcs, int fVerbose ) { extern int Dec_GraphToNetworkCount( Abc_Obj_t * pRoot, Dec_Graph_t * pGraph, int NodeMax, int LevelMax ); int fVeryVerbose = 0; int nVars = Vec_PtrSize(vFanins); int nWordsMax = Abc_Truth6WordNum(p->nNodeSizeMax); Dec_Graph_t * pFForm; Abc_Obj_t * pFanin; word * pTruth; abctime clk; int i, nNodesSaved, nNodesAdded, Required; p->nNodesConsidered++; Required = fUpdateLevel? Abc_ObjRequiredLevel(pNode) : ABC_INFINITY; // get the function of the cut clk = Abc_Clock(); pTruth = Abc_NodeConeTruth( p->vVars, p->vFuncs, nWordsMax, pNode, vFanins, p->vVisited ); p->timeTru += Abc_Clock() - clk; if ( pTruth == NULL ) return NULL; // always accept the case of constant node if ( Abc_NodeConeIsConst0(pTruth, nVars) || Abc_NodeConeIsConst1(pTruth, nVars) ) { p->nLastGain = Abc_NodeMffcSize( pNode ); p->nNodesGained += p->nLastGain; p->nNodesRefactored++; return Abc_NodeConeIsConst0(pTruth, nVars) ? Dec_GraphCreateConst0() : Dec_GraphCreateConst1(); } // get the factored form clk = Abc_Clock(); pFForm = (Dec_Graph_t *)Kit_TruthToGraph( (unsigned *)pTruth, nVars, p->vMemory ); p->timeFact += Abc_Clock() - clk; // mark the fanin boundary // (can mark only essential fanins, belonging to bNodeFunc!) Vec_PtrForEachEntry( Abc_Obj_t *, vFanins, pFanin, i ) pFanin->vFanouts.nSize++; // label MFFC with current traversal ID Abc_NtkIncrementTravId( pNode->pNtk ); nNodesSaved = Abc_NodeMffcLabelAig( pNode ); // unmark the fanin boundary and set the fanins as leaves in the form Vec_PtrForEachEntry( Abc_Obj_t *, vFanins, pFanin, i ) { pFanin->vFanouts.nSize--; Dec_GraphNode(pFForm, i)->pFunc = pFanin; } // detect how many new nodes will be added (while taking into account reused nodes) clk = Abc_Clock(); nNodesAdded = Dec_GraphToNetworkCount( pNode, pFForm, nNodesSaved, Required ); p->timeEval += Abc_Clock() - clk; // quit if there is no improvement if ( nNodesAdded == -1 || (nNodesAdded == nNodesSaved && !fUseZeros) ) { Dec_GraphFree( pFForm ); return NULL; } // compute the total gain in the number of nodes p->nLastGain = nNodesSaved - nNodesAdded; p->nNodesGained += p->nLastGain; p->nNodesRefactored++; // report the progress if ( fVeryVerbose ) { printf( "Node %6s : ", Abc_ObjName(pNode) ); printf( "Cone = %2d. ", vFanins->nSize ); printf( "FF = %2d. ", 1 + Dec_GraphNodeNum(pFForm) ); printf( "MFFC = %2d. ", nNodesSaved ); printf( "Add = %2d. ", nNodesAdded ); printf( "GAIN = %2d. ", p->nLastGain ); printf( "\n" ); } return pFForm; } /**Function************************************************************* Synopsis [Starts the resynthesis manager.] Description [] SideEffects [] SeeAlso [] ***********************************************************************/ Abc_ManRef_t * Abc_NtkManRefStart( int nNodeSizeMax, int nConeSizeMax, int fUseDcs, int fVerbose ) { Abc_ManRef_t * p; p = ABC_ALLOC( Abc_ManRef_t, 1 ); memset( p, 0, sizeof(Abc_ManRef_t) ); p->vCube = Vec_StrAlloc( 100 ); p->vVisited = Vec_PtrAlloc( 100 ); p->nNodeSizeMax = nNodeSizeMax; p->nConeSizeMax = nConeSizeMax; p->fVerbose = fVerbose; p->vVars = Vec_PtrAllocTruthTables( Abc_MaxInt(nNodeSizeMax, 6) ); p->vFuncs = Vec_PtrAlloc( 100 ); p->vMemory = Vec_IntAlloc( 1 << 16 ); return p; } /**Function************************************************************* Synopsis [Stops the resynthesis manager.] Description [] SideEffects [] SeeAlso [] ***********************************************************************/ void Abc_NtkManRefStop( Abc_ManRef_t * p ) { Vec_PtrFreeFree( p->vFuncs ); Vec_PtrFree( p->vVars ); Vec_IntFree( p->vMemory ); Vec_PtrFree( p->vVisited ); Vec_StrFree( p->vCube ); ABC_FREE( p ); } /**Function************************************************************* Synopsis [Stops the resynthesis manager.] Description [] SideEffects [] SeeAlso [] ***********************************************************************/ void Abc_NtkManRefPrintStats( Abc_ManRef_t * p ) { printf( "Refactoring statistics:\n" ); printf( "Nodes considered = %8d.\n", p->nNodesConsidered ); printf( "Nodes refactored = %8d.\n", p->nNodesRefactored ); printf( "Gain = %8d. (%6.2f %%).\n", p->nNodesBeg-p->nNodesEnd, 100.0*(p->nNodesBeg-p->nNodesEnd)/p->nNodesBeg ); ABC_PRT( "Cuts ", p->timeCut ); ABC_PRT( "Resynthesis", p->timeRes ); ABC_PRT( " BDD ", p->timeTru ); ABC_PRT( " DCs ", p->timeDcs ); ABC_PRT( " SOP ", p->timeSop ); ABC_PRT( " FF ", p->timeFact ); ABC_PRT( " Eval ", p->timeEval ); ABC_PRT( "AIG update ", p->timeNtk ); ABC_PRT( "TOTAL ", p->timeTotal ); } /**Function************************************************************* Synopsis [Performs incremental resynthesis of the AIG.] Description [Starting from each node, computes a reconvergence-driven cut, derives BDD of the cut function, constructs ISOP, factors the ISOP, and replaces the current implementation of the MFFC of the node by the new factored form, if the number of AIG nodes is reduced and the total number of levels of the AIG network is not increated. Returns the number of AIG nodes saved.] SideEffects [] SeeAlso [] ***********************************************************************/ int Abc_NtkRefactor( Abc_Ntk_t * pNtk, int nNodeSizeMax, int nConeSizeMax, int fUpdateLevel, int fUseZeros, int fUseDcs, int fVerbose ) { extern void Dec_GraphUpdateNetwork( Abc_Obj_t * pRoot, Dec_Graph_t * pGraph, int fUpdateLevel, int nGain ); ProgressBar * pProgress; Abc_ManRef_t * pManRef; Abc_ManCut_t * pManCut; Dec_Graph_t * pFForm; Vec_Ptr_t * vFanins; Abc_Obj_t * pNode; abctime clk, clkStart = Abc_Clock(); int i, nNodes; assert( Abc_NtkIsStrash(pNtk) ); // cleanup the AIG Abc_AigCleanup((Abc_Aig_t *)pNtk->pManFunc); // start the managers pManCut = Abc_NtkManCutStart( nNodeSizeMax, nConeSizeMax, 2, 1000 ); pManRef = Abc_NtkManRefStart( nNodeSizeMax, nConeSizeMax, fUseDcs, fVerbose ); pManRef->vLeaves = Abc_NtkManCutReadCutLarge( pManCut ); // compute the reverse levels if level update is requested if ( fUpdateLevel ) Abc_NtkStartReverseLevels( pNtk, 0 ); // resynthesize each node once pManRef->nNodesBeg = Abc_NtkNodeNum(pNtk); nNodes = Abc_NtkObjNumMax(pNtk); pProgress = Extra_ProgressBarStart( stdout, nNodes ); Abc_NtkForEachNode( pNtk, pNode, i ) { Extra_ProgressBarUpdate( pProgress, i, NULL ); // skip the constant node // if ( Abc_NodeIsConst(pNode) ) // continue; // skip persistant nodes if ( Abc_NodeIsPersistant(pNode) ) continue; // skip the nodes with many fanouts if ( Abc_ObjFanoutNum(pNode) > 1000 ) continue; // stop if all nodes have been tried once if ( i >= nNodes ) break; // compute a reconvergence-driven cut clk = Abc_Clock(); vFanins = Abc_NodeFindCut( pManCut, pNode, fUseDcs ); pManRef->timeCut += Abc_Clock() - clk; // evaluate this cut clk = Abc_Clock(); pFForm = Abc_NodeRefactor( pManRef, pNode, vFanins, fUpdateLevel, fUseZeros, fUseDcs, fVerbose ); pManRef->timeRes += Abc_Clock() - clk; if ( pFForm == NULL ) continue; // acceptable replacement found, update the graph clk = Abc_Clock(); Dec_GraphUpdateNetwork( pNode, pFForm, fUpdateLevel, pManRef->nLastGain ); pManRef->timeNtk += Abc_Clock() - clk; Dec_GraphFree( pFForm ); } Extra_ProgressBarStop( pProgress ); pManRef->timeTotal = Abc_Clock() - clkStart; pManRef->nNodesEnd = Abc_NtkNodeNum(pNtk); // print statistics of the manager if ( fVerbose ) Abc_NtkManRefPrintStats( pManRef ); // delete the managers Abc_NtkManCutStop( pManCut ); Abc_NtkManRefStop( pManRef ); // put the nodes into the DFS order and reassign their IDs Abc_NtkReassignIds( pNtk ); // Abc_AigCheckFaninOrder( pNtk->pManFunc ); // fix the levels if ( fUpdateLevel ) Abc_NtkStopReverseLevels( pNtk ); else Abc_NtkLevel( pNtk ); // check if ( !Abc_NtkCheck( pNtk ) ) { printf( "Abc_NtkRefactor: The network check has failed.\n" ); return 0; } return 1; } //////////////////////////////////////////////////////////////////////// /// END OF FILE /// //////////////////////////////////////////////////////////////////////// ABC_NAMESPACE_IMPL_END