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Diffstat (limited to 'src/opt/fret/fretMain.c')
| -rw-r--r-- | src/opt/fret/fretMain.c | 864 |
1 files changed, 864 insertions, 0 deletions
diff --git a/src/opt/fret/fretMain.c b/src/opt/fret/fretMain.c new file mode 100644 index 00000000..4ce78a9b --- /dev/null +++ b/src/opt/fret/fretMain.c @@ -0,0 +1,864 @@ +/**CFile**************************************************************** + + FileName [fretMain.c] + + SystemName [ABC: Logic synthesis and verification system.] + + PackageName [Flow-based retiming package.] + + Synopsis [Main file for retiming package.] + + Author [Aaron Hurst] + + Affiliation [UC Berkeley] + + Date [Ver. 1.0. Started - January 1, 2008.] + + Revision [$Id: fretMain.c,v 1.00 2008/01/01 00:00:00 ahurst Exp $] + +***********************************************************************/ + +#include "abc.h" +#include "vec.h" +#include "fretime.h" + +//////////////////////////////////////////////////////////////////////// +/// DECLARATIONS /// +//////////////////////////////////////////////////////////////////////// + +static void Abc_FlowRetime_AddDummyFanin( Abc_Obj_t * pObj ); + +static void Abc_FlowRetime_MarkBlocks( Abc_Ntk_t * pNtk ); +static void Abc_FlowRetime_MarkReachable_rec( Abc_Obj_t * pObj, char end ); +static int Abc_FlowRetime_PushFlows( Abc_Ntk_t * pNtk ); +static int Abc_FlowRetime_ImplementCut( Abc_Ntk_t * pNtk ); +static void Abc_FlowRetime_RemoveLatchBubbles( Abc_Obj_t * pLatch ); + +static void Abc_FlowRetime_VerifyPathLatencies( Abc_Ntk_t * pNtk ); +static int Abc_FlowRetime_VerifyPathLatencies_rec( Abc_Obj_t * pObj, int markD ); + +extern void Abc_NtkMarkCone_rec( Abc_Obj_t * pObj, int fForward ); +extern Abc_Ntk_t * Abc_NtkRestrash( Abc_Ntk_t * pNtk, bool fCleanup ); + +int fIsForward, fComputeInitState; +int fSinkDistTerminate; +Vec_Int_t *vSinkDistHist; +int maxDelayCon; + +int fPathError = 0; + +//////////////////////////////////////////////////////////////////////// +/// FUNCTION DEFINITIONS /// +//////////////////////////////////////////////////////////////////////// + +/**Function************************************************************* + + Synopsis [Performs minimum-register retiming.] + + Description [] + + SideEffects [] + + SeeAlso [] + +***********************************************************************/ +Abc_Ntk_t * +Abc_FlowRetime_MinReg( Abc_Ntk_t * pNtk, int fVerbose, int fComputeInitState_, + int fForwardOnly, int fBackwardOnly, int nMaxIters, + int maxDelay ) { + + int i, j, nNodes, nLatches, flow, last, cut; + int iteration = 0; + Flow_Data_t *pDataArray; + Abc_Obj_t *pObj, *pNext; + + fComputeInitState = fComputeInitState_; + + printf("Flow-based minimum-register retiming...\n"); + + if (!Abc_NtkHasOnlyLatchBoxes(pNtk)) { + printf("\tERROR: Can not retime with black/white boxes\n"); + return pNtk; + } + + maxDelayCon = maxDelay; + if (maxDelayCon) { + printf("\tmax delay constraint = %d\n", maxDelayCon); + if (maxDelayCon < (i = Abc_NtkLevel(pNtk))) { + printf("ERROR: max delay constraint must be > current max delay (%d)\n", i); + return pNtk; + } + } + + // print info about type of network + printf("\tnetlist type = "); + if (Abc_NtkIsNetlist( pNtk )) printf("netlist/"); + else if (Abc_NtkIsLogic( pNtk )) printf("logic/"); + else if (Abc_NtkIsStrash( pNtk )) printf("strash/"); + else printf("***unknown***/"); + if (Abc_NtkHasSop( pNtk )) printf("sop\n"); + else if (Abc_NtkHasBdd( pNtk )) printf("bdd\n"); + else if (Abc_NtkHasAig( pNtk )) printf("aig\n"); + else if (Abc_NtkHasMapping( pNtk )) printf("mapped\n"); + else printf("***unknown***\n"); + + printf("\tinitial reg count = %d\n", Abc_NtkLatchNum(pNtk)); + + // remove bubbles from latch boxes + Abc_FlowRetime_PrintInitStateInfo(pNtk); + printf("\tpushing bubbles out of latch boxes\n"); + Abc_NtkForEachLatch( pNtk, pObj, i ) + Abc_FlowRetime_RemoveLatchBubbles(pObj); + Abc_FlowRetime_PrintInitStateInfo(pNtk); + + // check for box inputs/outputs + Abc_NtkForEachLatch( pNtk, pObj, i ) { + assert(Abc_ObjFaninNum(pObj) == 1); + assert(Abc_ObjFanoutNum(pObj) == 1); + assert(!Abc_ObjFaninC0(pObj)); + + pNext = Abc_ObjFanin0(pObj); + assert(Abc_ObjIsBi(pNext)); + assert(Abc_ObjFaninNum(pNext) <= 1); + if(Abc_ObjFaninNum(pNext) == 0) // every Bi should have a fanin + Abc_FlowRetime_AddDummyFanin( pNext ); + + pNext = Abc_ObjFanout0(pObj); + assert(Abc_ObjIsBo(pNext)); + assert(Abc_ObjFaninNum(pNext) == 1); + assert(!Abc_ObjFaninC0(pNext)); + } + + nLatches = Abc_NtkLatchNum( pNtk ); + nNodes = Abc_NtkObjNumMax( pNtk )+1; + + // build histogram + vSinkDistHist = Vec_IntStart( nNodes*2+10 ); + + // create Flow_Data structure + pDataArray = (Flow_Data_t *)malloc(sizeof(Flow_Data_t)*nNodes); + memset(pDataArray, 0, sizeof(Flow_Data_t)*nNodes); + Abc_NtkForEachObj( pNtk, pObj, i ) + Abc_ObjSetCopy( pObj, (void *)(&pDataArray[i]) ); + + // (i) forward retiming loop + fIsForward = 1; + + if (!fBackwardOnly) do { + if (iteration == nMaxIters) break; + + printf("\tforward iteration %d\n", iteration); + last = Abc_NtkLatchNum( pNtk ); + + Abc_FlowRetime_MarkBlocks( pNtk ); + flow = Abc_FlowRetime_PushFlows( pNtk ); + cut = Abc_FlowRetime_ImplementCut( pNtk ); + + // clear all + memset(pDataArray, 0, sizeof(Flow_Data_t)*nNodes); + iteration++; + } while( flow != last ); + + // print info about initial states + if (fComputeInitState) + Abc_FlowRetime_PrintInitStateInfo( pNtk ); + + // (ii) backward retiming loop + fIsForward = 0; + iteration = 0; + + if (!fForwardOnly) { + if (fComputeInitState) { + Abc_FlowRetime_SetupBackwardInit( pNtk ); + } + + do { + if (iteration == nMaxIters) break; + + printf("\tbackward iteration %d\n", iteration); + last = Abc_NtkLatchNum( pNtk ); + + Abc_FlowRetime_MarkBlocks( pNtk ); + flow = Abc_FlowRetime_PushFlows( pNtk ); + cut = Abc_FlowRetime_ImplementCut( pNtk ); + + // clear all + memset(pDataArray, 0, sizeof(Flow_Data_t)*nNodes); + iteration++; + + } while( flow != last ); + + // compute initial states + if (fComputeInitState) { + Abc_FlowRetime_SolveBackwardInit( pNtk ); + Abc_FlowRetime_PrintInitStateInfo( pNtk ); + } + } + + // clear pCopy field + Abc_NtkForEachObj( pNtk, pObj, i ) { + Abc_ObjSetCopy( pObj, NULL ); + + // if not computing init state, set all latches to DC + if (!fComputeInitState && Abc_ObjIsLatch(pObj)) + Abc_LatchSetInitDc(pObj); + } + + // restrash if necessary + if (Abc_NtkIsStrash(pNtk)) { + Abc_NtkReassignIds( pNtk ); + pNtk = Abc_NtkRestrash( pNtk, 1 ); + } + +#if defined(DEBUG_CHECK) + Abc_NtkDoCheck( pNtk ); +#endif + + // deallocate space + free(pDataArray); + if (vSinkDistHist) Vec_IntFree(vSinkDistHist); + + printf("\tfinal reg count = %d\n", Abc_NtkLatchNum(pNtk)); + + return pNtk; +} + +/**Function************************************************************* + + Synopsis [Pushes latch bubbles outside of box.] + + Description [If network is an AIG, a fCompl0 is allowed to remain on + the BI node.] + + SideEffects [] + + SeeAlso [] + +***********************************************************************/ +void +Abc_FlowRetime_RemoveLatchBubbles( Abc_Obj_t * pLatch ) { + int i, j, k, bubble = 0; + Abc_Ntk_t *pNtk = Abc_ObjNtk( pLatch ); + Abc_Obj_t *pBi, *pBo, *pInv; + + pBi = Abc_ObjFanin0(pLatch); + pBo = Abc_ObjFanout0(pLatch); + assert(!Abc_ObjIsComplement(pBi)); + assert(!Abc_ObjIsComplement(pBo)); + + // push bubbles on BO into latch box + if (Abc_ObjFaninC0(pBo) && Abc_ObjFanoutNum(pBo) > 0) { + bubble = 1; + if (Abc_LatchIsInit0(pLatch)) Abc_LatchSetInit1(pLatch); + else if (Abc_LatchIsInit1(pLatch)) Abc_LatchSetInit0(pLatch); + } + + // absorb bubbles on BI + pBi->fCompl0 ^= bubble ^ Abc_ObjFaninC0(pLatch); + + // convert bubble to INV if not AIG + if (!Abc_NtkHasAig( pNtk ) && Abc_ObjFaninC0(pBi)) { + pBi->fCompl0 = 0; + pInv = Abc_NtkCreateNodeInv( pNtk, Abc_ObjFanin0(pBi) ); + Abc_ObjPatchFanin( pBi, Abc_ObjFanin0(pBi), pInv ); + } + + pBo->fCompl0 = 0; + pLatch->fCompl0 = 0; +} + + +/**Function************************************************************* + + Synopsis [Marks nodes in TFO/TFI of PI/PO.] + + Description [Sets flow data flag BLOCK appropriately.] + + SideEffects [] + + SeeAlso [] + +***********************************************************************/ +void +Abc_FlowRetime_MarkBlocks( Abc_Ntk_t * pNtk ) { + int i; + Abc_Obj_t *pObj; + + if (fIsForward){ + // mark the frontier + Abc_NtkForEachPo( pNtk, pObj, i ) + pObj->fMarkA = 1; + Abc_NtkForEachLatch( pNtk, pObj, i ) + { + pObj->fMarkA = 1; + } + // mark the nodes reachable from the PIs + Abc_NtkForEachPi( pNtk, pObj, i ) + Abc_NtkMarkCone_rec( pObj, fIsForward ); + } else { + // mark the frontier + Abc_NtkForEachPi( pNtk, pObj, i ) + pObj->fMarkA = 1; + Abc_NtkForEachLatch( pNtk, pObj, i ) + { + pObj->fMarkA = 1; + } + // mark the nodes reachable from the POs + Abc_NtkForEachPo( pNtk, pObj, i ) + Abc_NtkMarkCone_rec( pObj, fIsForward ); + } + + // copy marks + Abc_NtkForEachObj( pNtk, pObj, i ) { + if (pObj->fMarkA) { + pObj->fMarkA = 0; + if (!Abc_ObjIsLatch(pObj) && + !Abc_ObjIsPi(pObj)) + FSET(pObj, BLOCK); + } + } +} + + +/**Function************************************************************* + + Synopsis [Computes maximum flow.] + + Description [] + + SideEffects [Leaves VISITED flags on source-reachable nodes.] + + SeeAlso [] + +***********************************************************************/ +int +Abc_FlowRetime_PushFlows( Abc_Ntk_t * pNtk ) { + int i, j, flow = 0, last, srcDist = 0; + Abc_Obj_t *pObj, *pObj2; + + fSinkDistTerminate = 0; + dfsfast_preorder( pNtk ); + + // (i) fast max-flow computation + while(!fSinkDistTerminate && srcDist < MAX_DIST) { + srcDist = MAX_DIST; + Abc_NtkForEachLatch( pNtk, pObj, i ) + if (FDATA(pObj)->e_dist) + srcDist = MIN(srcDist, FDATA(pObj)->e_dist); + + Abc_NtkForEachLatch( pNtk, pObj, i ) { + if (srcDist == FDATA(pObj)->e_dist && + dfsfast_e( pObj, NULL )) { +#ifdef DEBUG_PRINT_FLOWS + printf("\n\n"); +#endif + flow++; + } + } + } + + printf("\t\tmax-flow1 = %d \t", flow); + + // (ii) complete max-flow computation + // also, marks source-reachable nodes + do { + last = flow; + Abc_NtkForEachLatch( pNtk, pObj, i ) { + if (dfsplain_e( pObj, NULL )) { +#ifdef DEBUG_PRINT_FLOWS + printf("\n\n"); +#endif + flow++; + Abc_NtkForEachObj( pNtk, pObj2, j ) + FUNSET( pObj2, VISITED ); + } + } + } while (flow > last); + + printf("max-flow2 = %d\n", flow); + + return flow; +} + + +/**Function************************************************************* + + Synopsis [Restores latch boxes.] + + Description [Latchless BI/BO nodes are removed. Latch boxes are + restored around remaining latches.] + + SideEffects [Deletes nodes as appropriate.] + + SeeAlso [] + +***********************************************************************/ +void +Abc_FlowRetime_FixLatchBoxes( Abc_Ntk_t *pNtk, Vec_Ptr_t *vBoxIns ) { + int i; + Abc_Obj_t *pObj, *pNext, *pBo = NULL, *pBi = NULL; + Vec_Ptr_t *vFreeBi = Vec_PtrAlloc( 100 ); + Vec_Ptr_t *vFreeBo = Vec_PtrAlloc( 100 ); + Vec_Ptr_t *vNodes; + + // 1. remove empty bi/bo pairs + while(Vec_PtrSize( vBoxIns )) { + pBi = (Abc_Obj_t *)Vec_PtrPop( vBoxIns ); + assert(Abc_ObjIsBi(pBi)); + assert(Abc_ObjFanoutNum(pBi) == 1); + assert(Abc_ObjFaninNum(pBi) == 1); + pBo = Abc_ObjFanout0(pBi); + assert(!Abc_ObjFaninC0(pBo)); + + if (Abc_ObjIsBo(pBo)) { + // an empty bi/bo pair + + Abc_ObjRemoveFanins( pBo ); + // transfer complement from BI, if present + assert(!Abc_ObjIsComplement(Abc_ObjFanin0(pBi))); + Abc_ObjBetterTransferFanout( pBo, Abc_ObjFanin0(pBi), Abc_ObjFaninC0(pBi) ); + + Abc_ObjRemoveFanins( pBi ); + pBi->fCompl0 = 0; + Vec_PtrPush( vFreeBi, pBi ); + Vec_PtrPush( vFreeBo, pBo ); + + // free names + // if (Nm_ManFindNameById(pNtk->pManName, Abc_ObjId(pBi))) + // Nm_ManDeleteIdName( pNtk->pManName, Abc_ObjId(pBi)); + //if (Nm_ManFindNameById(pNtk->pManName, Abc_ObjId(pBo))) + // Nm_ManDeleteIdName( pNtk->pManName, Abc_ObjId(pBo)); + + // check for complete detachment + assert(Abc_ObjFaninNum(pBi) == 0); + assert(Abc_ObjFanoutNum(pBi) == 0); + assert(Abc_ObjFaninNum(pBo) == 0); + assert(Abc_ObjFanoutNum(pBo) == 0); + } else assert(Abc_ObjIsLatch(pBo)); + } + + // 2. add bi/bos as necessary for latches + Abc_NtkForEachLatch( pNtk, pObj, i ) { + assert(Abc_ObjFaninNum(pObj) == 1); + if (Abc_ObjFanoutNum(pObj)) + pBo = Abc_ObjFanout0(pObj); + else pBo = NULL; + pBi = Abc_ObjFanin0(pObj); + + // add BO + if (!pBo || !Abc_ObjIsBo(pBo)) { + pBo = (Abc_Obj_t *)Vec_PtrPop( vFreeBo ); + if (Abc_ObjFanoutNum(pObj)) Abc_ObjTransferFanout( pObj, pBo ); + Abc_ObjAddFanin( pBo, pObj ); + } + // add BI + if (!Abc_ObjIsBi(pBi)) { + pBi = (Abc_Obj_t *)Vec_PtrPop( vFreeBi ); + assert(Abc_ObjFaninNum(pBi) == 0); + Abc_ObjAddFanin( pBi, Abc_ObjFanin0(pObj) ); + pBi->fCompl0 = pObj->fCompl0; + Abc_ObjRemoveFanins( pObj ); + Abc_ObjAddFanin( pObj, pBi ); + } + } + + // delete remaining BIs and BOs + while(Vec_PtrSize( vFreeBi )) { + pObj = (Abc_Obj_t *)Vec_PtrPop( vFreeBi ); + Abc_NtkDeleteObj( pObj ); + } + while(Vec_PtrSize( vFreeBo )) { + pObj = (Abc_Obj_t *)Vec_PtrPop( vFreeBo ); + Abc_NtkDeleteObj( pObj ); + } + +#if defined(DEBUG_CHECK) + Abc_NtkForEachObj( pNtk, pObj, i ) { + if (Abc_ObjIsBo(pObj)) { + assert(Abc_ObjFaninNum(pObj) == 1); + assert(Abc_ObjIsLatch(Abc_ObjFanin0(pObj))); + } + if (Abc_ObjIsBi(pObj)) { + assert(Abc_ObjFaninNum(pObj) == 1); + assert(Abc_ObjFanoutNum(pObj) == 1); + assert(Abc_ObjIsLatch(Abc_ObjFanout0(pObj))); + } + if (Abc_ObjIsLatch(pObj)) { + assert(Abc_ObjFanoutNum(pObj) == 1); + assert(Abc_ObjFaninNum(pObj) == 1); + } + } +#endif + + Vec_PtrFree( vFreeBi ); + Vec_PtrFree( vFreeBo ); +} + + +/**Function************************************************************* + + Synopsis [Checks register count along all combinational paths.] + + Description [] + + SideEffects [] + + SeeAlso [] + +***********************************************************************/ +void +Abc_FlowRetime_VerifyPathLatencies( Abc_Ntk_t * pNtk ) { + int i; + Abc_Obj_t *pObj; + fPathError = 0; + + printf("\t\tVerifying latency along all paths..."); + + Abc_NtkForEachObj( pNtk, pObj, i ) { + if (Abc_ObjIsBo(pObj)) { + Abc_FlowRetime_VerifyPathLatencies_rec( pObj, 0 ); + } else if (!fIsForward && Abc_ObjIsPi(pObj)) { + Abc_FlowRetime_VerifyPathLatencies_rec( pObj, 0 ); + } + + if (fPathError) { + if (Abc_ObjFaninNum(pObj) > 0) { + printf("fanin "); + print_node(Abc_ObjFanin0(pObj)); + } + printf("\n"); + exit(0); + } + } + + printf(" ok\n"); + + Abc_NtkForEachObj( pNtk, pObj, i ) { + pObj->fMarkA = 0; + pObj->fMarkB = 0; + pObj->fMarkC = 0; + } +} + + +int +Abc_FlowRetime_VerifyPathLatencies_rec( Abc_Obj_t * pObj, int markD ) { + int i, j; + Abc_Obj_t *pNext; + int fCare = 0; + int markC = pObj->fMarkC; + + if (!pObj->fMarkB) { + pObj->fMarkB = 1; // visited + + if (Abc_ObjIsLatch(pObj)) + markC = 1; // latch in output + + if (!fIsForward && !Abc_ObjIsPo(pObj) && !Abc_ObjFanoutNum(pObj)) + return -1; // dangling non-PO outputs : don't care what happens + + Abc_ObjForEachFanout( pObj, pNext, i ) { + // reached end of cycle? + if ( Abc_ObjIsBo(pNext) || + (fIsForward && Abc_ObjIsPo(pNext)) ) { + if (!markD && !Abc_ObjIsLatch(pObj)) { + printf("\nERROR: no-latch path (end)\n"); + print_node(pNext); + printf("\n"); + fPathError = 1; + } + } else if (!fIsForward && Abc_ObjIsPo(pNext)) { + if (markD || Abc_ObjIsLatch(pObj)) { + printf("\nERROR: extra-latch path to outputs\n"); + print_node(pNext); + printf("\n"); + fPathError = 1; + } + } else { + j = Abc_FlowRetime_VerifyPathLatencies_rec( pNext, markD || Abc_ObjIsLatch(pObj) ); + if (j >= 0) { + markC |= j; + fCare = 1; + } + } + + if (fPathError) { + print_node(pObj); + printf("\n"); + return 0; + } + } + } + + if (!fCare) return -1; + + if (markC && markD) { + printf("\nERROR: mult-latch path\n"); + print_node(pObj); + printf("\n"); + fPathError = 1; + } + if (!markC && !markD) { + printf("\nERROR: no-latch path (inter)\n"); + print_node(pObj); + printf("\n"); + fPathError = 1; + } + + return (pObj->fMarkC = markC); +} + + +/**Function************************************************************* + + Synopsis [Copies initial state from latches to BO nodes.] + + Description [Initial states are marked on BO nodes with INIT_0 and + INIT_1 flags in their Flow_Data structures.] + + SideEffects [] + + SeeAlso [] + +***********************************************************************/ +void +Abc_FlowRetime_CopyInitState( Abc_Obj_t * pSrc, Abc_Obj_t * pDest ) { + Abc_Obj_t *pObj; + + if (!fComputeInitState) return; + + assert(Abc_ObjIsLatch(pSrc)); + assert(Abc_ObjFanin0(pDest) == pSrc); + assert(!Abc_ObjFaninC0(pDest)); + + FUNSET(pDest, INIT_CARE); + if (Abc_LatchIsInit0(pSrc)) { + FSET(pDest, INIT_0); + } else if (Abc_LatchIsInit1(pSrc)) { + FSET(pDest, INIT_1); + } + + if (!fIsForward) { + pObj = Abc_ObjData(pSrc); + assert(Abc_ObjIsPi(pObj)); + FDATA(pDest)->pInitObj = pObj; + } +} + + +/**Function************************************************************* + + Synopsis [Implements min-cut.] + + Description [Requires source-reachable nodes to be marked VISITED.] + + SideEffects [] + + SeeAlso [] + +***********************************************************************/ +int +Abc_FlowRetime_ImplementCut( Abc_Ntk_t * pNtk ) { + int i, j, cut = 0, unmoved = 0; + Abc_Obj_t *pObj, *pReg, *pNext, *pBo = NULL, *pBi = NULL; + Vec_Ptr_t *vFreeRegs = Vec_PtrAlloc( Abc_NtkLatchNum(pNtk) ); + Vec_Ptr_t *vBoxIns = Vec_PtrAlloc( Abc_NtkLatchNum(pNtk) ); + Vec_Ptr_t *vMove = Vec_PtrAlloc( 100 ); + + // remove latches from netlist + Abc_NtkForEachLatch( pNtk, pObj, i ) { + pBo = Abc_ObjFanout0(pObj); + pBi = Abc_ObjFanin0(pObj); + assert(Abc_ObjIsBo(pBo) && Abc_ObjIsBi(pBi)); + Vec_PtrPush( vBoxIns, pBi ); + + // copy initial state values to BO + Abc_FlowRetime_CopyInitState( pObj, pBo ); + + // re-use latch elsewhere + Vec_PtrPush( vFreeRegs, pObj ); + FSET(pBo, CROSS_BOUNDARY); + + // cut out of netlist + Abc_ObjPatchFanin( pBo, pObj, pBi ); + Abc_ObjRemoveFanins( pObj ); + + // free name + // if (Nm_ManFindNameById(pNtk->pManName, Abc_ObjId(pObj))) + // Nm_ManDeleteIdName( pNtk->pManName, Abc_ObjId(pObj)); + } + + // insert latches into netlist + Abc_NtkForEachObj( pNtk, pObj, i ) { + if (Abc_ObjIsLatch( pObj )) continue; + + // a latch is required on every node that lies across the min-cit + assert(!fIsForward || !FTEST(pObj, VISITED_E) || FTEST(pObj, VISITED_R)); + if (FTEST(pObj, VISITED_R) && !FTEST(pObj, VISITED_E)) { + assert(FTEST(pObj, FLOW)); + + // count size of cut + cut++; + if ((fIsForward && Abc_ObjIsBo(pObj)) || + (!fIsForward && Abc_ObjIsBi(pObj))) + unmoved++; + + // only insert latch between fanouts that lie across min-cut + // some fanout paths may be cut at deeper points + Abc_ObjForEachFanout( pObj, pNext, j ) + if (fIsForward) { + if (!FTEST(pNext, VISITED_R) || + FTEST(pNext, BLOCK) || + FTEST(pNext, CROSS_BOUNDARY) || + Abc_ObjIsLatch(pNext)) + Vec_PtrPush(vMove, pNext); + } else { + if (FTEST(pNext, VISITED_E) || + FTEST(pNext, CROSS_BOUNDARY)) + Vec_PtrPush(vMove, pNext); + } + if (Vec_PtrSize(vMove) == 0) + print_node(pObj); + + assert(Vec_PtrSize(vMove) > 0); + + // insert one of re-useable registers + assert(Vec_PtrSize( vFreeRegs )); + pReg = (Abc_Obj_t *)Vec_PtrPop( vFreeRegs ); + + Abc_ObjAddFanin(pReg, pObj); + while(Vec_PtrSize( vMove )) { + pNext = (Abc_Obj_t *)Vec_PtrPop( vMove ); + Abc_ObjPatchFanin( pNext, pObj, pReg ); + if (Abc_ObjIsBi(pNext)) assert(Abc_ObjFaninNum(pNext) == 1); + + } + if (Abc_ObjIsBi(pObj)) assert(Abc_ObjFaninNum(pObj) == 1); + } + } + +#if defined(DEBUG_CHECK) + Abc_FlowRetime_VerifyPathLatencies( pNtk ); +#endif + + // delete remaining latches + while(Vec_PtrSize( vFreeRegs )) { + pReg = (Abc_Obj_t *)Vec_PtrPop( vFreeRegs ); + Abc_NtkDeleteObj( pReg ); + } + + // update initial states + Abc_FlowRetime_InitState( pNtk ); + + // restore latch boxes + Abc_FlowRetime_FixLatchBoxes( pNtk, vBoxIns ); + + Vec_PtrFree( vFreeRegs ); + Vec_PtrFree( vMove ); + Vec_PtrFree( vBoxIns ); + + printf("\t\tmin-cut = %d (unmoved = %d)\n", cut, unmoved); + return cut; +} + +/**Function************************************************************* + + Synopsis [Adds dummy fanin.] + + Description [] + + SideEffects [] + + SeeAlso [] + +***********************************************************************/ +void +Abc_FlowRetime_AddDummyFanin( Abc_Obj_t * pObj ) { + Abc_Ntk_t *pNtk = Abc_ObjNtk( pObj ); + + if (Abc_NtkHasAig(pNtk)) + Abc_ObjAddFanin(pObj, Abc_AigConst1( pNtk )); + else + Abc_ObjAddFanin(pObj, Abc_NtkCreateNodeConst0( pNtk )); +} + + +/**Function************************************************************* + + Synopsis [Prints information about a node.] + + Description [Debuging.] + + SideEffects [] + + SeeAlso [] + +***********************************************************************/ +void +print_node(Abc_Obj_t *pObj) { + int i; + Abc_Obj_t * pNext; + char m[6]; + + m[0] = 0; + if (pObj->fMarkA) + strcat(m, "A"); + if (pObj->fMarkB) + strcat(m, "B"); + if (pObj->fMarkC) + strcat(m, "C"); + + printf("node %d type=%d (%x%s) fanouts {", Abc_ObjId(pObj), Abc_ObjType(pObj), FDATA(pObj)->mark, m); + Abc_ObjForEachFanout( pObj, pNext, i ) + printf("%d (%d),", Abc_ObjId(pNext), FDATA(pNext)->mark); + printf("} fanins {"); + Abc_ObjForEachFanin( pObj, pNext, i ) + printf("%d (%d),", Abc_ObjId(pNext), FDATA(pNext)->mark); + printf("} "); +} + +void +print_node2(Abc_Obj_t *pObj) { + int i; + Abc_Obj_t * pNext; + char m[6]; + + m[0] = 0; + if (pObj->fMarkA) + strcat(m, "A"); + if (pObj->fMarkB) + strcat(m, "B"); + if (pObj->fMarkC) + strcat(m, "C"); + + printf("node %d type=%d fanouts {", Abc_ObjId(pObj), Abc_ObjType(pObj), m); + Abc_ObjForEachFanout( pObj, pNext, i ) + printf("%d ,", Abc_ObjId(pNext)); + printf("} fanins {"); + Abc_ObjForEachFanin( pObj, pNext, i ) + printf("%d ,", Abc_ObjId(pNext)); + printf("} "); +} + + +/**Function************************************************************* + + Synopsis [Transfers fanout.] + + Description [Does not produce an error if there is no fanout. + Complements as necessary.] + + SideEffects [] + + SeeAlso [] + +***********************************************************************/ +void +Abc_ObjBetterTransferFanout( Abc_Obj_t * pFrom, Abc_Obj_t * pTo, int compl ) { + Abc_Obj_t *pNext; + + while(Abc_ObjFanoutNum(pFrom) > 0) { + pNext = Abc_ObjFanout0(pFrom); + Abc_ObjPatchFanin( pNext, pFrom, Abc_ObjNotCond(pTo, compl) ); + } +} |