/**CFile**************************************************************** FileName [mapperMatch.c] PackageName [MVSIS 1.3: Multi-valued logic synthesis system.] Synopsis [Generic technology mapping engine.] Author [MVSIS Group] Affiliation [UC Berkeley] Date [Ver. 2.0. Started - June 1, 2004.] Revision [$Id: mapperMatch.c,v 1.7 2004/09/30 21:18:10 satrajit Exp $] ***********************************************************************/ #include "mapperInt.h" #include "misc/util/utilNam.h" #include "map/scl/sclCon.h" ABC_NAMESPACE_IMPL_START /* A potential improvement: When an internal node is not used in the mapping, its required times are set to be +infinity. So when we recover area, we try to find the best match for area and completely disregard the delay for the nodes that are not currently used in the mapping because any match whose arrival times are less than the required times (+infinity) can be used. It may be possible to develop a better approach to recover area for the nodes that are not currently used in the mapping... */ //////////////////////////////////////////////////////////////////////// /// DECLARATIONS /// //////////////////////////////////////////////////////////////////////// //////////////////////////////////////////////////////////////////////// /// FUNCTION DEFINITIONS /// //////////////////////////////////////////////////////////////////////// /**Function************************************************************* Synopsis [Cleans the match.] Description [] SideEffects [] SeeAlso [] ***********************************************************************/ void Map_MatchClean( Map_Match_t * pMatch ) { memset( pMatch, 0, sizeof(Map_Match_t) ); pMatch->AreaFlow = MAP_FLOAT_LARGE; // unassigned pMatch->tArrive.Rise = MAP_FLOAT_LARGE; // unassigned pMatch->tArrive.Fall = MAP_FLOAT_LARGE; // unassigned pMatch->tArrive.Worst = MAP_FLOAT_LARGE; // unassigned } /**Function************************************************************* Synopsis [Compares two matches.] Description [Returns 1 if the second match is better. Otherwise returns 0.] SideEffects [] SeeAlso [] ***********************************************************************/ int Map_MatchCompare( Map_Man_t * pMan, Map_Match_t * pM1, Map_Match_t * pM2, int fDoingArea ) { if ( !fDoingArea ) { // compare the arrival times if ( pM1->tArrive.Worst < pM2->tArrive.Worst - pMan->fEpsilon ) return 0; if ( pM1->tArrive.Worst > pM2->tArrive.Worst + pMan->fEpsilon ) return 1; // compare the areas or area flows if ( pM1->AreaFlow < pM2->AreaFlow - pMan->fEpsilon ) return 0; if ( pM1->AreaFlow > pM2->AreaFlow + pMan->fEpsilon ) return 1; // compare the fanout limits if ( pM1->pSuperBest->nFanLimit > pM2->pSuperBest->nFanLimit ) return 0; if ( pM1->pSuperBest->nFanLimit < pM2->pSuperBest->nFanLimit ) return 1; // compare the number of leaves if ( pM1->pSuperBest->nFanins < pM2->pSuperBest->nFanins ) return 0; if ( pM1->pSuperBest->nFanins > pM2->pSuperBest->nFanins ) return 1; // otherwise prefer the old cut return 0; } else { // compare the areas or area flows if ( pM1->AreaFlow < pM2->AreaFlow - pMan->fEpsilon ) return 0; if ( pM1->AreaFlow > pM2->AreaFlow + pMan->fEpsilon ) return 1; // compare the arrival times if ( pM1->tArrive.Worst < pM2->tArrive.Worst - pMan->fEpsilon ) return 0; if ( pM1->tArrive.Worst > pM2->tArrive.Worst + pMan->fEpsilon ) return 1; // compare the fanout limits if ( pM1->pSuperBest->nFanLimit > pM2->pSuperBest->nFanLimit ) return 0; if ( pM1->pSuperBest->nFanLimit < pM2->pSuperBest->nFanLimit ) return 1; // compare the number of leaves if ( pM1->pSuperBest->nFanins < pM2->pSuperBest->nFanins ) return 0; if ( pM1->pSuperBest->nFanins > pM2->pSuperBest->nFanins ) return 1; // otherwise prefer the old cut return 0; } } /**Function************************************************************* Synopsis [Find the best matching of the cut.] Description [The parameters: the node (pNode), the cut (pCut), the phase to be matched (fPhase), and the upper bound on the arrival times of the cut (fWorstLimit). This procedure goes through the matching supergates up to the phase assignment, and selects the best supergate, which will be used to map the cut. As a result of calling this procedure the matching information is written into pMatch.] SideEffects [] SeeAlso [] ***********************************************************************/ int Map_MatchNodeCut( Map_Man_t * p, Map_Node_t * pNode, Map_Cut_t * pCut, int fPhase, float fWorstLimit ) { Map_Match_t MatchBest, * pMatch = pCut->M + fPhase; Map_Super_t * pSuper; int i, Counter; // save the current match of the cut MatchBest = *pMatch; // go through the supergates for ( pSuper = pMatch->pSupers, Counter = 0; pSuper; pSuper = pSuper->pNext, Counter++ ) { p->nMatches++; // this is an attempt to reduce the runtime of matching and area // at the cost of rare and very minor increase in delay // (the supergates are sorted by increasing area) if ( Counter == 30 ) break; // go through different phases of the given match and supergate pMatch->pSuperBest = pSuper; for ( i = 0; i < (int)pSuper->nPhases; i++ ) { p->nPhases++; // find the overall phase of this match pMatch->uPhaseBest = pMatch->uPhase ^ pSuper->uPhases[i]; if ( p->fMappingMode == 0 ) { // get the arrival time Map_TimeCutComputeArrival( pNode, pCut, fPhase, fWorstLimit ); // skip the cut if the arrival times exceed the required times if ( pMatch->tArrive.Worst > fWorstLimit + p->fEpsilon ) continue; // get the area (area flow) pMatch->AreaFlow = Map_CutGetAreaFlow( pCut, fPhase ); } else { // get the area (area flow) if ( p->fMappingMode == 2 || p->fMappingMode == 3 ) pMatch->AreaFlow = Map_CutGetAreaDerefed( pCut, fPhase ); else if ( p->fMappingMode == 4 ) pMatch->AreaFlow = Map_SwitchCutGetDerefed( pNode, pCut, fPhase ); else pMatch->AreaFlow = Map_CutGetAreaFlow( pCut, fPhase ); // skip if the cut is too large if ( pMatch->AreaFlow > MatchBest.AreaFlow + p->fEpsilon ) continue; // get the arrival time Map_TimeCutComputeArrival( pNode, pCut, fPhase, fWorstLimit ); // skip the cut if the arrival times exceed the required times if ( pMatch->tArrive.Worst > fWorstLimit + p->fEpsilon ) continue; } // if the cut is non-trivial, compare it if ( Map_MatchCompare( p, &MatchBest, pMatch, p->fMappingMode ) ) { MatchBest = *pMatch; // if we are mapping for delay, the worst-case limit should be reduced if ( p->fMappingMode == 0 ) fWorstLimit = MatchBest.tArrive.Worst; } } } // set the best match *pMatch = MatchBest; // recompute the arrival time and area (area flow) of this cut if ( pMatch->pSuperBest ) { Map_TimeCutComputeArrival( pNode, pCut, fPhase, MAP_FLOAT_LARGE ); if ( p->fMappingMode == 2 || p->fMappingMode == 3 ) pMatch->AreaFlow = Map_CutGetAreaDerefed( pCut, fPhase ); else if ( p->fMappingMode == 4 ) pMatch->AreaFlow = Map_SwitchCutGetDerefed( pNode, pCut, fPhase ); else pMatch->AreaFlow = Map_CutGetAreaFlow( pCut, fPhase ); } return 1; } /**Function************************************************************* Synopsis [Find the matching of one polarity of the node.] Description [] SideEffects [] SeeAlso [] ***********************************************************************/ int Map_MatchNodePhase( Map_Man_t * p, Map_Node_t * pNode, int fPhase ) { Map_Match_t MatchBest, * pMatch; Map_Cut_t * pCut, * pCutBest; float Area1 = 0.0; // Suppress "might be used uninitialized float Area2, fWorstLimit; // skip the cuts that have been unassigned during area recovery pCutBest = pNode->pCutBest[fPhase]; if ( p->fMappingMode != 0 && pCutBest == NULL ) return 1; // recompute the arrival times of the current best match // because the arrival times of the fanins may have changed // as a result of remapping fanins in the topological order if ( p->fMappingMode != 0 ) { Map_TimeCutComputeArrival( pNode, pCutBest, fPhase, MAP_FLOAT_LARGE ); // make sure that the required times are met // assert( pCutBest->M[fPhase].tArrive.Rise < pNode->tRequired[fPhase].Rise + p->fEpsilon ); // assert( pCutBest->M[fPhase].tArrive.Fall < pNode->tRequired[fPhase].Fall + p->fEpsilon ); } // recompute the exact area of the current best match // because the exact area of the fanins may have changed // as a result of remapping fanins in the topological order if ( p->fMappingMode == 2 || p->fMappingMode == 3 ) { pMatch = pCutBest->M + fPhase; if ( pNode->nRefAct[fPhase] > 0 || (pNode->pCutBest[!fPhase] == NULL && pNode->nRefAct[!fPhase] > 0) ) pMatch->AreaFlow = Area1 = Map_CutDeref( pCutBest, fPhase ); else pMatch->AreaFlow = Area1 = Map_CutGetAreaDerefed( pCutBest, fPhase ); } else if ( p->fMappingMode == 4 ) { pMatch = pCutBest->M + fPhase; if ( pNode->nRefAct[fPhase] > 0 || (pNode->pCutBest[!fPhase] == NULL && pNode->nRefAct[!fPhase] > 0) ) pMatch->AreaFlow = Area1 = Map_SwitchCutDeref( pNode, pCutBest, fPhase ); else pMatch->AreaFlow = Area1 = Map_SwitchCutGetDerefed( pNode, pCutBest, fPhase ); } // save the old mapping if ( pCutBest ) MatchBest = pCutBest->M[fPhase]; else Map_MatchClean( &MatchBest ); // select the new best cut fWorstLimit = pNode->tRequired[fPhase].Worst; for ( pCut = pNode->pCuts->pNext; pCut; pCut = pCut->pNext ) { // limit gate sizes based on fanout count if ( p->fSkipFanout && ((pNode->nRefs > 3 && pCut->nLeaves > 2) || (pNode->nRefs > 1 && pCut->nLeaves > 3)) ) continue; pMatch = pCut->M + fPhase; if ( pMatch->pSupers == NULL ) continue; // find the matches for the cut Map_MatchNodeCut( p, pNode, pCut, fPhase, fWorstLimit ); if ( pMatch->pSuperBest == NULL || pMatch->tArrive.Worst > fWorstLimit + p->fEpsilon ) continue; // if the cut can be matched compare the matchings if ( Map_MatchCompare( p, &MatchBest, pMatch, p->fMappingMode ) ) { pCutBest = pCut; MatchBest = *pMatch; // if we are mapping for delay, the worst-case limit should be tightened if ( p->fMappingMode == 0 ) fWorstLimit = MatchBest.tArrive.Worst; } } if ( pCutBest == NULL ) return 1; // set the new mapping pNode->pCutBest[fPhase] = pCutBest; pCutBest->M[fPhase] = MatchBest; // reference the new cut if it used if ( p->fMappingMode >= 2 && (pNode->nRefAct[fPhase] > 0 || (pNode->pCutBest[!fPhase] == NULL && pNode->nRefAct[!fPhase] > 0)) ) { if ( p->fMappingMode == 2 || p->fMappingMode == 3 ) Area2 = Map_CutRef( pNode->pCutBest[fPhase], fPhase ); else if ( p->fMappingMode == 4 ) Area2 = Map_SwitchCutRef( pNode, pNode->pCutBest[fPhase], fPhase ); else assert( 0 ); // assert( Area2 < Area1 + p->fEpsilon ); } // make sure that the requited times are met // assert( MatchBest.tArrive.Rise < pNode->tRequired[fPhase].Rise + p->fEpsilon ); // assert( MatchBest.tArrive.Fall < pNode->tRequired[fPhase].Fall + p->fEpsilon ); return 1; } /**Function************************************************************* Synopsis [Sets the PI arrival times.] Description [] SideEffects [] SeeAlso [] ***********************************************************************/ void Map_MappingSetPiArrivalTimes( Map_Man_t * p ) { Map_Node_t * pNode; int i; for ( i = 0; i < p->nInputs; i++ ) { pNode = p->pInputs[i]; // set the arrival time of the positive phase if ( Scl_ConIsRunning() ) { float Time = Scl_ConGetInArrFloat( i ); pNode->tArrival[1].Fall = Time; pNode->tArrival[1].Rise = Time; pNode->tArrival[1].Worst = Time; } else pNode->tArrival[1] = p->pInputArrivals[i]; pNode->tArrival[1].Rise += p->pNodeDelays ? p->pNodeDelays[pNode->Num] : 0; pNode->tArrival[1].Fall += p->pNodeDelays ? p->pNodeDelays[pNode->Num] : 0; pNode->tArrival[1].Worst += p->pNodeDelays ? p->pNodeDelays[pNode->Num] : 0; // set the arrival time of the negative phase pNode->tArrival[0].Rise = pNode->tArrival[1].Fall + p->pSuperLib->tDelayInv.Rise; pNode->tArrival[0].Fall = pNode->tArrival[1].Rise + p->pSuperLib->tDelayInv.Fall; pNode->tArrival[0].Worst = MAP_MAX(pNode->tArrival[0].Rise, pNode->tArrival[0].Fall); } } /**function************************************************************* synopsis [Computes the exact area associated with the cut.] description [] sideeffects [] seealso [] ***********************************************************************/ float Map_TimeMatchWithInverter( Map_Man_t * p, Map_Match_t * pMatch ) { Map_Time_t tArrInv; tArrInv.Fall = pMatch->tArrive.Rise + p->pSuperLib->tDelayInv.Fall; tArrInv.Rise = pMatch->tArrive.Fall + p->pSuperLib->tDelayInv.Rise; tArrInv.Worst = MAP_MAX( tArrInv.Rise, tArrInv.Fall ); return tArrInv.Worst; } /**Function************************************************************* Synopsis [Attempts dropping one phase of the node.] Description [] SideEffects [] SeeAlso [] ***********************************************************************/ void Map_NodeTryDroppingOnePhase( Map_Man_t * p, Map_Node_t * pNode ) { Map_Match_t * pMatchBest0, * pMatchBest1; float tWorst0Using1, tWorst1Using0; int fUsePhase1, fUsePhase0; // nothing to do if one of the phases is already dropped if ( pNode->pCutBest[0] == NULL || pNode->pCutBest[1] == NULL ) return; // do not drop while recovering area flow if ( p->fMappingMode == 1 )//|| p->fMappingMode == 2 ) return; // get the pointers to the matches of the best cuts pMatchBest0 = pNode->pCutBest[0]->M + 0; pMatchBest1 = pNode->pCutBest[1]->M + 1; // get the worst arrival times of each phase // implemented using the other phase with inverter added tWorst0Using1 = Map_TimeMatchWithInverter( p, pMatchBest1 ); tWorst1Using0 = Map_TimeMatchWithInverter( p, pMatchBest0 ); // consider the case of mapping for delay if ( p->fMappingMode == 0 && p->DelayTarget < ABC_INFINITY ) { // if the arrival time of a phase is larger than the arrival time // of the opposite phase plus the inverter, drop this phase if ( pMatchBest0->tArrive.Worst > tWorst0Using1 + p->fEpsilon ) pNode->pCutBest[0] = NULL; else if ( pMatchBest1->tArrive.Worst > tWorst1Using0 + p->fEpsilon ) pNode->pCutBest[1] = NULL; return; } // do not perform replacement if one of the phases is unused if ( pNode->nRefAct[0] == 0 || pNode->nRefAct[1] == 0 ) return; // check if replacement of each phase is possible using required times fUsePhase0 = fUsePhase1 = 0; if ( p->fMappingMode == 2 ) { fUsePhase0 = (pNode->tRequired[1].Worst > tWorst1Using0 + 3*p->pSuperLib->tDelayInv.Worst + p->fEpsilon); fUsePhase1 = (pNode->tRequired[0].Worst > tWorst0Using1 + 3*p->pSuperLib->tDelayInv.Worst + p->fEpsilon); } else if ( p->fMappingMode == 3 || p->fMappingMode == 4 ) { fUsePhase0 = (pNode->tRequired[1].Worst > tWorst1Using0 + p->fEpsilon); fUsePhase1 = (pNode->tRequired[0].Worst > tWorst0Using1 + p->fEpsilon); } if ( !fUsePhase0 && !fUsePhase1 ) return; // if replacement is possible both ways, use the one that works better if ( fUsePhase0 && fUsePhase1 ) { if ( pMatchBest0->AreaFlow < pMatchBest1->AreaFlow ) fUsePhase1 = 0; else fUsePhase0 = 0; } // only one phase should be used assert( fUsePhase0 ^ fUsePhase1 ); // set the corresponding cut to NULL if ( fUsePhase0 ) { // deref phase 1 cut if necessary if ( p->fMappingMode >= 2 && pNode->nRefAct[1] > 0 ) Map_CutDeref( pNode->pCutBest[1], 1 ); // get rid of the cut pNode->pCutBest[1] = NULL; // ref phase 0 cut if necessary if ( p->fMappingMode >= 2 && pNode->nRefAct[0] == 0 ) Map_CutRef( pNode->pCutBest[0], 0 ); } else { // deref phase 0 cut if necessary if ( p->fMappingMode >= 2 && pNode->nRefAct[0] > 0 ) Map_CutDeref( pNode->pCutBest[0], 0 ); // get rid of the cut pNode->pCutBest[0] = NULL; // ref phase 1 cut if necessary if ( p->fMappingMode >= 2 && pNode->nRefAct[1] == 0 ) Map_CutRef( pNode->pCutBest[1], 1 ); } } /**Function************************************************************* Synopsis [Transfers the arrival times from the best cuts to the node.] Description [] SideEffects [] SeeAlso [] ***********************************************************************/ void Map_NodeTransferArrivalTimes( Map_Man_t * p, Map_Node_t * pNode ) { // if both phases are available, set their arrival times if ( pNode->pCutBest[0] && pNode->pCutBest[1] ) { pNode->tArrival[0] = pNode->pCutBest[0]->M[0].tArrive; pNode->tArrival[1] = pNode->pCutBest[1]->M[1].tArrive; } // if only one phase is available, compute the arrival time of other phase else if ( pNode->pCutBest[0] ) { pNode->tArrival[0] = pNode->pCutBest[0]->M[0].tArrive; pNode->tArrival[1].Rise = pNode->tArrival[0].Fall + p->pSuperLib->tDelayInv.Rise; pNode->tArrival[1].Fall = pNode->tArrival[0].Rise + p->pSuperLib->tDelayInv.Fall; pNode->tArrival[1].Worst = MAP_MAX(pNode->tArrival[1].Rise, pNode->tArrival[1].Fall); } else if ( pNode->pCutBest[1] ) { pNode->tArrival[1] = pNode->pCutBest[1]->M[1].tArrive; pNode->tArrival[0].Rise = pNode->tArrival[1].Fall + p->pSuperLib->tDelayInv.Rise; pNode->tArrival[0].Fall = pNode->tArrival[1].Rise + p->pSuperLib->tDelayInv.Fall; pNode->tArrival[0].Worst = MAP_MAX(pNode->tArrival[0].Rise, pNode->tArrival[0].Fall); } else { assert( 0 ); } // assert( pNode->tArrival[0].Rise < pNode->tRequired[0].Rise + p->fEpsilon ); // assert( pNode->tArrival[0].Fall < pNode->tRequired[0].Fall + p->fEpsilon ); // assert( pNode->tArrival[1].Rise < pNode->tRequired[1].Rise + p->fEpsilon ); // assert( pNode->tArrival[1].Fall < pNode->tRequired[1].Fall + p->fEpsilon ); } /**Function************************************************************* Synopsis [Computes the best matches of the nodes.] Description [Uses parameter p->fMappingMode to decide how to assign the matches for both polarities of the node. While the matches are being assigned, one of them may turn out to be better than the other (in terms of delay, for example). In this case, the worse match can be permanently dropped, and the corresponding pointer set to NULL.] SideEffects [] SeeAlso [] ***********************************************************************/ int Map_MappingMatches( Map_Man_t * p ) { ProgressBar * pProgress; Map_Node_t * pNode; int i; assert( p->fMappingMode >= 0 && p->fMappingMode <= 4 ); // use the externally given PI arrival times if ( p->fMappingMode == 0 ) Map_MappingSetPiArrivalTimes( p ); // estimate the fanouts if ( p->fMappingMode == 0 ) Map_MappingEstimateRefsInit( p ); else if ( p->fMappingMode == 1 ) Map_MappingEstimateRefs( p ); // the PI cuts are matched in the cut computation package // in the loop below we match the internal nodes pProgress = Extra_ProgressBarStart( stdout, p->vMapObjs->nSize ); for ( i = 0; i < p->vMapObjs->nSize; i++ ) { pNode = p->vMapObjs->pArray[i]; if ( Map_NodeIsBuf(pNode) ) { assert( pNode->p2 == NULL ); pNode->tArrival[0] = Map_Regular(pNode->p1)->tArrival[ Map_IsComplement(pNode->p1)]; pNode->tArrival[1] = Map_Regular(pNode->p1)->tArrival[!Map_IsComplement(pNode->p1)]; continue; } // skip primary inputs and secondary nodes if mapping with choices if ( !Map_NodeIsAnd( pNode ) || pNode->pRepr ) continue; // make sure that at least one non-trival cut is present if ( pNode->pCuts->pNext == NULL ) { Extra_ProgressBarStop( pProgress ); printf( "\nError: A node in the mapping graph does not have feasible cuts.\n" ); return 0; } // match negative phase if ( !Map_MatchNodePhase( p, pNode, 0 ) ) { Extra_ProgressBarStop( pProgress ); return 0; } // match positive phase if ( !Map_MatchNodePhase( p, pNode, 1 ) ) { Extra_ProgressBarStop( pProgress ); return 0; } // make sure that at least one phase is mapped if ( pNode->pCutBest[0] == NULL && pNode->pCutBest[1] == NULL ) { printf( "\nError: Could not match both phases of AIG node %d.\n", pNode->Num ); printf( "Please make sure that the supergate library has equivalents of AND2 or NAND2.\n" ); printf( "If such supergates exist in the library, report a bug.\n" ); Extra_ProgressBarStop( pProgress ); return 0; } // if both phases are assigned, check if one of them can be dropped Map_NodeTryDroppingOnePhase( p, pNode ); // set the arrival times of the node using the best cuts Map_NodeTransferArrivalTimes( p, pNode ); // update the progress bar Extra_ProgressBarUpdate( pProgress, i, "Matches ..." ); } Extra_ProgressBarStop( pProgress ); return 1; } //////////////////////////////////////////////////////////////////////// /// END OF FILE /// //////////////////////////////////////////////////////////////////////// ABC_NAMESPACE_IMPL_END