diff options
Diffstat (limited to 'src/base/abci/abcBalance.c')
| -rw-r--r-- | src/base/abci/abcBalance.c | 613 |
1 files changed, 613 insertions, 0 deletions
diff --git a/src/base/abci/abcBalance.c b/src/base/abci/abcBalance.c new file mode 100644 index 00000000..f9b3384e --- /dev/null +++ b/src/base/abci/abcBalance.c @@ -0,0 +1,613 @@ +/**CFile**************************************************************** + + FileName [abcBalance.c] + + SystemName [ABC: Logic synthesis and verification system.] + + PackageName [Network and node package.] + + Synopsis [Performs global balancing of the AIG by the number of levels.] + + Author [Alan Mishchenko] + + Affiliation [UC Berkeley] + + Date [Ver. 1.0. Started - June 20, 2005.] + + Revision [$Id: abcBalance.c,v 1.00 2005/06/20 00:00:00 alanmi Exp $] + +***********************************************************************/ + +#include "abc.h" + +//////////////////////////////////////////////////////////////////////// +/// DECLARATIONS /// +//////////////////////////////////////////////////////////////////////// + +static void Abc_NtkBalancePerform( Abc_Ntk_t * pNtk, Abc_Ntk_t * pNtkAig, bool fDuplicate, bool fSelective, bool fUpdateLevel ); +static Abc_Obj_t * Abc_NodeBalance_rec( Abc_Ntk_t * pNtkNew, Abc_Obj_t * pNode, Vec_Vec_t * vStorage, int Level, bool fDuplicate, bool fSelective, bool fUpdateLevel ); +static Vec_Ptr_t * Abc_NodeBalanceCone( Abc_Obj_t * pNode, Vec_Vec_t * vSuper, int Level, int fDuplicate, bool fSelective ); +static int Abc_NodeBalanceCone_rec( Abc_Obj_t * pNode, Vec_Ptr_t * vSuper, bool fFirst, bool fDuplicate, bool fSelective ); +static void Abc_NtkMarkCriticalNodes( Abc_Ntk_t * pNtk ); +static Vec_Ptr_t * Abc_NodeBalanceConeExor( Abc_Obj_t * pNode ); + + +//////////////////////////////////////////////////////////////////////// +/// FUNCTION DEFINITIONS /// +//////////////////////////////////////////////////////////////////////// + +/**Function************************************************************* + + Synopsis [Balances the AIG network.] + + Description [] + + SideEffects [] + + SeeAlso [] + +***********************************************************************/ +Abc_Ntk_t * Abc_NtkBalance( Abc_Ntk_t * pNtk, bool fDuplicate, bool fSelective, bool fUpdateLevel ) +{ + extern void Abc_NtkHaigTranfer( Abc_Ntk_t * pNtkOld, Abc_Ntk_t * pNtkNew ); + Abc_Ntk_t * pNtkAig; + assert( Abc_NtkIsStrash(pNtk) ); + // compute the required times + if ( fSelective ) + { + Abc_NtkStartReverseLevels( pNtk, 0 ); + Abc_NtkMarkCriticalNodes( pNtk ); + } + // perform balancing + pNtkAig = Abc_NtkStartFrom( pNtk, ABC_NTK_STRASH, ABC_FUNC_AIG ); + // transfer HAIG + Abc_NtkHaigTranfer( pNtk, pNtkAig ); + // perform balancing + Abc_NtkBalancePerform( pNtk, pNtkAig, fDuplicate, fSelective, fUpdateLevel ); + Abc_NtkFinalize( pNtk, pNtkAig ); + // undo the required times + if ( fSelective ) + { + Abc_NtkStopReverseLevels( pNtk ); + Abc_NtkCleanMarkA( pNtk ); + } + if ( pNtk->pExdc ) + pNtkAig->pExdc = Abc_NtkDup( pNtk->pExdc ); + // make sure everything is okay + if ( !Abc_NtkCheck( pNtkAig ) ) + { + printf( "Abc_NtkBalance: The network check has failed.\n" ); + Abc_NtkDelete( pNtkAig ); + return NULL; + } + return pNtkAig; +} + +/**Function************************************************************* + + Synopsis [Balances the AIG network.] + + Description [] + + SideEffects [] + + SeeAlso [] + +***********************************************************************/ +void Abc_NtkBalancePerform( Abc_Ntk_t * pNtk, Abc_Ntk_t * pNtkAig, bool fDuplicate, bool fSelective, bool fUpdateLevel ) +{ + int fCheck = 1; + ProgressBar * pProgress; + Vec_Vec_t * vStorage; + Abc_Obj_t * pNode, * pDriver; + int i; + + // set the level of PIs of AIG according to the arrival times of the old network + Abc_NtkSetNodeLevelsArrival( pNtk ); + // allocate temporary storage for supergates + vStorage = Vec_VecStart( 10 ); + // perform balancing of POs + pProgress = Extra_ProgressBarStart( stdout, Abc_NtkCoNum(pNtk) ); + Abc_NtkForEachCo( pNtk, pNode, i ) + { + Extra_ProgressBarUpdate( pProgress, i, NULL ); + // strash the driver node + pDriver = Abc_ObjFanin0(pNode); + Abc_NodeBalance_rec( pNtkAig, pDriver, vStorage, 0, fDuplicate, fSelective, fUpdateLevel ); + } + Extra_ProgressBarStop( pProgress ); + Vec_VecFree( vStorage ); +} + +/**Function************************************************************* + + Synopsis [Finds the left bound on the next candidate to be paired.] + + Description [The nodes in the array are in the decreasing order of levels. + The last node in the array has the smallest level. By default it would be paired + with the next node on the left. However, it may be possible to pair it with some + other node on the left, in such a way that the new node is shared. This procedure + finds the index of the left-most node, which can be paired with the last node.] + + SideEffects [] + + SeeAlso [] + +***********************************************************************/ +int Abc_NodeBalanceFindLeft( Vec_Ptr_t * vSuper ) +{ + Abc_Obj_t * pNodeRight, * pNodeLeft; + int Current; + // if two or less nodes, pair with the first + if ( Vec_PtrSize(vSuper) < 3 ) + return 0; + // set the pointer to the one before the last + Current = Vec_PtrSize(vSuper) - 2; + pNodeRight = Vec_PtrEntry( vSuper, Current ); + // go through the nodes to the left of this one + for ( Current--; Current >= 0; Current-- ) + { + // get the next node on the left + pNodeLeft = Vec_PtrEntry( vSuper, Current ); + // if the level of this node is different, quit the loop + if ( Abc_ObjRegular(pNodeLeft)->Level != Abc_ObjRegular(pNodeRight)->Level ) + break; + } + Current++; + // get the node, for which the equality holds + pNodeLeft = Vec_PtrEntry( vSuper, Current ); + assert( Abc_ObjRegular(pNodeLeft)->Level == Abc_ObjRegular(pNodeRight)->Level ); + return Current; +} + +/**Function************************************************************* + + Synopsis [Moves closer to the end the node that is best for sharing.] + + Description [If there is no node with sharing, randomly chooses one of + the legal nodes.] + + SideEffects [] + + SeeAlso [] + +***********************************************************************/ +void Abc_NodeBalancePermute( Abc_Ntk_t * pNtkNew, Vec_Ptr_t * vSuper, int LeftBound ) +{ + Abc_Obj_t * pNode1, * pNode2, * pNode3; + int RightBound, i; + // get the right bound + RightBound = Vec_PtrSize(vSuper) - 2; + assert( LeftBound <= RightBound ); + if ( LeftBound == RightBound ) + return; + // get the two last nodes + pNode1 = Vec_PtrEntry( vSuper, RightBound + 1 ); + pNode2 = Vec_PtrEntry( vSuper, RightBound ); + // find the first node that can be shared + for ( i = RightBound; i >= LeftBound; i-- ) + { + pNode3 = Vec_PtrEntry( vSuper, i ); + if ( Abc_AigAndLookup( pNtkNew->pManFunc, pNode1, pNode3 ) ) + { + if ( pNode3 == pNode2 ) + return; + Vec_PtrWriteEntry( vSuper, i, pNode2 ); + Vec_PtrWriteEntry( vSuper, RightBound, pNode3 ); + return; + } + } +/* + // we did not find the node to share, randomize choice + { + int Choice = rand() % (RightBound - LeftBound + 1); + pNode3 = Vec_PtrEntry( vSuper, LeftBound + Choice ); + if ( pNode3 == pNode2 ) + return; + Vec_PtrWriteEntry( vSuper, LeftBound + Choice, pNode2 ); + Vec_PtrWriteEntry( vSuper, RightBound, pNode3 ); + } +*/ +} + +/**Function************************************************************* + + Synopsis [Rebalances the multi-input node rooted at pNodeOld.] + + Description [] + + SideEffects [] + + SeeAlso [] + +***********************************************************************/ +Abc_Obj_t * Abc_NodeBalance_rec( Abc_Ntk_t * pNtkNew, Abc_Obj_t * pNodeOld, Vec_Vec_t * vStorage, int Level, bool fDuplicate, bool fSelective, bool fUpdateLevel ) +{ + Abc_Aig_t * pMan = pNtkNew->pManFunc; + Abc_Obj_t * pNodeNew, * pNode1, * pNode2; + Vec_Ptr_t * vSuper; + int i, LeftBound; + assert( !Abc_ObjIsComplement(pNodeOld) ); + // return if the result if known + if ( pNodeOld->pCopy ) + return pNodeOld->pCopy; + assert( Abc_ObjIsNode(pNodeOld) ); + // get the implication supergate +// Abc_NodeBalanceConeExor( pNodeOld ); + vSuper = Abc_NodeBalanceCone( pNodeOld, vStorage, Level, fDuplicate, fSelective ); + if ( vSuper->nSize == 0 ) + { // it means that the supergate contains two nodes in the opposite polarity + pNodeOld->pCopy = Abc_ObjNot(Abc_AigConst1(pNtkNew)); + return pNodeOld->pCopy; + } + // for each old node, derive the new well-balanced node + for ( i = 0; i < vSuper->nSize; i++ ) + { + pNodeNew = Abc_NodeBalance_rec( pNtkNew, Abc_ObjRegular(vSuper->pArray[i]), vStorage, Level + 1, fDuplicate, fSelective, fUpdateLevel ); + vSuper->pArray[i] = Abc_ObjNotCond( pNodeNew, Abc_ObjIsComplement(vSuper->pArray[i]) ); + } + if ( vSuper->nSize < 2 ) + printf( "BUG!\n" ); + // sort the new nodes by level in the decreasing order + Vec_PtrSort( vSuper, Abc_NodeCompareLevelsDecrease ); + // balance the nodes + assert( vSuper->nSize > 1 ); + while ( vSuper->nSize > 1 ) + { + // find the left bound on the node to be paired + LeftBound = (!fUpdateLevel)? 0 : Abc_NodeBalanceFindLeft( vSuper ); + // find the node that can be shared (if no such node, randomize choice) + Abc_NodeBalancePermute( pNtkNew, vSuper, LeftBound ); + // pull out the last two nodes + pNode1 = Vec_PtrPop(vSuper); + pNode2 = Vec_PtrPop(vSuper); + Abc_VecObjPushUniqueOrderByLevel( vSuper, Abc_AigAnd(pMan, pNode1, pNode2) ); + } + // make sure the balanced node is not assigned + assert( pNodeOld->pCopy == NULL ); + // mark the old node with the new node + pNodeOld->pCopy = vSuper->pArray[0]; + vSuper->nSize = 0; +// if ( Abc_ObjRegular(pNodeOld->pCopy) == Abc_AigConst1(pNtkNew) ) +// printf( "Constant node\n" ); +// assert( pNodeOld->Level >= Abc_ObjRegular(pNodeOld->pCopy)->Level ); + // update HAIG + if ( Abc_ObjRegular(pNodeOld->pCopy)->pNtk->pHaig ) + Hop_ObjCreateChoice( pNodeOld->pEquiv, Abc_ObjRegular(pNodeOld->pCopy)->pEquiv ); + return pNodeOld->pCopy; +} + +/**Function************************************************************* + + Synopsis [Collects the nodes in the cone delimited by fMarkA==1.] + + Description [Returns -1 if the AND-cone has the same node in both polarities. + Returns 1 if the AND-cone has the same node in the same polarity. Returns 0 + if the AND-cone has no repeated nodes.] + + SideEffects [] + + SeeAlso [] + +***********************************************************************/ +Vec_Ptr_t * Abc_NodeBalanceCone( Abc_Obj_t * pNode, Vec_Vec_t * vStorage, int Level, int fDuplicate, bool fSelective ) +{ + Vec_Ptr_t * vNodes; + int RetValue, i; + assert( !Abc_ObjIsComplement(pNode) ); + // extend the storage + if ( Vec_VecSize( vStorage ) <= Level ) + Vec_VecPush( vStorage, Level, 0 ); + // get the temporary array of nodes + vNodes = Vec_VecEntry( vStorage, Level ); + Vec_PtrClear( vNodes ); + // collect the nodes in the implication supergate + RetValue = Abc_NodeBalanceCone_rec( pNode, vNodes, 1, fDuplicate, fSelective ); + assert( vNodes->nSize > 1 ); + // unmark the visited nodes + for ( i = 0; i < vNodes->nSize; i++ ) + Abc_ObjRegular((Abc_Obj_t *)vNodes->pArray[i])->fMarkB = 0; + // if we found the node and its complement in the same implication supergate, + // return empty set of nodes (meaning that we should use constant-0 node) + if ( RetValue == -1 ) + vNodes->nSize = 0; + return vNodes; +} + + +/**Function************************************************************* + + Synopsis [Collects the nodes in the cone delimited by fMarkA==1.] + + Description [Returns -1 if the AND-cone has the same node in both polarities. + Returns 1 if the AND-cone has the same node in the same polarity. Returns 0 + if the AND-cone has no repeated nodes.] + + SideEffects [] + + SeeAlso [] + +***********************************************************************/ +int Abc_NodeBalanceCone_rec( Abc_Obj_t * pNode, Vec_Ptr_t * vSuper, bool fFirst, bool fDuplicate, bool fSelective ) +{ + int RetValue1, RetValue2, i; + // check if the node is visited + if ( Abc_ObjRegular(pNode)->fMarkB ) + { + // check if the node occurs in the same polarity + for ( i = 0; i < vSuper->nSize; i++ ) + if ( vSuper->pArray[i] == pNode ) + return 1; + // check if the node is present in the opposite polarity + for ( i = 0; i < vSuper->nSize; i++ ) + if ( vSuper->pArray[i] == Abc_ObjNot(pNode) ) + return -1; + assert( 0 ); + return 0; + } + // if the new node is complemented or a PI, another gate begins + if ( !fFirst && (Abc_ObjIsComplement(pNode) || !Abc_ObjIsNode(pNode) || !fDuplicate && !fSelective && (Abc_ObjFanoutNum(pNode) > 1)) ) + { + Vec_PtrPush( vSuper, pNode ); + Abc_ObjRegular(pNode)->fMarkB = 1; + return 0; + } + assert( !Abc_ObjIsComplement(pNode) ); + assert( Abc_ObjIsNode(pNode) ); + // go through the branches + RetValue1 = Abc_NodeBalanceCone_rec( Abc_ObjChild0(pNode), vSuper, 0, fDuplicate, fSelective ); + RetValue2 = Abc_NodeBalanceCone_rec( Abc_ObjChild1(pNode), vSuper, 0, fDuplicate, fSelective ); + if ( RetValue1 == -1 || RetValue2 == -1 ) + return -1; + // return 1 if at least one branch has a duplicate + return RetValue1 || RetValue2; +} + + +/**Function************************************************************* + + Synopsis [] + + Description [] + + SideEffects [] + + SeeAlso [] + +***********************************************************************/ +int Abc_NodeBalanceConeExor_rec( Abc_Obj_t * pNode, Vec_Ptr_t * vSuper, bool fFirst ) +{ + int RetValue1, RetValue2, i; + // check if the node occurs in the same polarity + for ( i = 0; i < vSuper->nSize; i++ ) + if ( vSuper->pArray[i] == pNode ) + return 1; + // if the new node is complemented or a PI, another gate begins + if ( !fFirst && (!pNode->fExor || !Abc_ObjIsNode(pNode)) ) + { + Vec_PtrPush( vSuper, pNode ); + return 0; + } + assert( !Abc_ObjIsComplement(pNode) ); + assert( Abc_ObjIsNode(pNode) ); + assert( pNode->fExor ); + // go through the branches + RetValue1 = Abc_NodeBalanceConeExor_rec( Abc_ObjFanin0(Abc_ObjFanin0(pNode)), vSuper, 0 ); + RetValue2 = Abc_NodeBalanceConeExor_rec( Abc_ObjFanin1(Abc_ObjFanin0(pNode)), vSuper, 0 ); + if ( RetValue1 == -1 || RetValue2 == -1 ) + return -1; + // return 1 if at least one branch has a duplicate + return RetValue1 || RetValue2; +} + +/**Function************************************************************* + + Synopsis [] + + Description [] + + SideEffects [] + + SeeAlso [] + +***********************************************************************/ +Vec_Ptr_t * Abc_NodeBalanceConeExor( Abc_Obj_t * pNode ) +{ + Vec_Ptr_t * vSuper; + if ( !pNode->fExor ) + return NULL; + vSuper = Vec_PtrAlloc( 10 ); + Abc_NodeBalanceConeExor_rec( pNode, vSuper, 1 ); + printf( "%d ", Vec_PtrSize(vSuper) ); + Vec_PtrFree( vSuper ); + return NULL; +} + + + +/**Function************************************************************* + + Synopsis [Collects the nodes in the implication supergate.] + + Description [] + + SideEffects [] + + SeeAlso [] + +***********************************************************************/ +Vec_Ptr_t * Abc_NodeFindCone_rec( Abc_Obj_t * pNode ) +{ + Vec_Ptr_t * vNodes; + Abc_Obj_t * pNodeC, * pNodeT, * pNodeE; + int RetValue, i; + assert( !Abc_ObjIsComplement(pNode) ); + if ( Abc_ObjIsCi(pNode) ) + return NULL; + // start the new array + vNodes = Vec_PtrAlloc( 4 ); + // if the node is the MUX collect its fanins + if ( Abc_NodeIsMuxType(pNode) ) + { + pNodeC = Abc_NodeRecognizeMux( pNode, &pNodeT, &pNodeE ); + Vec_PtrPush( vNodes, Abc_ObjRegular(pNodeC) ); + Vec_PtrPushUnique( vNodes, Abc_ObjRegular(pNodeT) ); + Vec_PtrPushUnique( vNodes, Abc_ObjRegular(pNodeE) ); + } + else + { + // collect the nodes in the implication supergate + RetValue = Abc_NodeBalanceCone_rec( pNode, vNodes, 1, 1, 0 ); + assert( vNodes->nSize > 1 ); + // unmark the visited nodes + Vec_PtrForEachEntry( vNodes, pNode, i ) + Abc_ObjRegular(pNode)->fMarkB = 0; + // if we found the node and its complement in the same implication supergate, + // return empty set of nodes (meaning that we should use constant-0 node) + if ( RetValue == -1 ) + vNodes->nSize = 0; + } + // call for the fanin + Vec_PtrForEachEntry( vNodes, pNode, i ) + { + pNode = Abc_ObjRegular(pNode); + if ( pNode->pCopy ) + continue; + pNode->pCopy = (Abc_Obj_t *)Abc_NodeFindCone_rec( pNode ); + } + return vNodes; +} + +/**Function************************************************************* + + Synopsis [Attaches the implication supergates to internal nodes.] + + Description [] + + SideEffects [] + + SeeAlso [] + +***********************************************************************/ +void Abc_NtkBalanceAttach( Abc_Ntk_t * pNtk ) +{ + Abc_Obj_t * pNode; + int i; + Abc_NtkCleanCopy( pNtk ); + Abc_NtkForEachCo( pNtk, pNode, i ) + { + pNode = Abc_ObjFanin0(pNode); + if ( pNode->pCopy ) + continue; + pNode->pCopy = (Abc_Obj_t *)Abc_NodeFindCone_rec( pNode ); + } +} + +/**Function************************************************************* + + Synopsis [Attaches the implication supergates to internal nodes.] + + Description [] + + SideEffects [] + + SeeAlso [] + +***********************************************************************/ +void Abc_NtkBalanceDetach( Abc_Ntk_t * pNtk ) +{ + Abc_Obj_t * pNode; + int i; + Abc_NtkForEachNode( pNtk, pNode, i ) + if ( pNode->pCopy ) + { + Vec_PtrFree( (Vec_Ptr_t *)pNode->pCopy ); + pNode->pCopy = NULL; + } +} + +/**Function************************************************************* + + Synopsis [Compute levels of implication supergates.] + + Description [] + + SideEffects [] + + SeeAlso [] + +***********************************************************************/ +int Abc_NtkBalanceLevel_rec( Abc_Obj_t * pNode ) +{ + Vec_Ptr_t * vSuper; + Abc_Obj_t * pFanin; + int i, LevelMax; + assert( !Abc_ObjIsComplement(pNode) ); + if ( pNode->Level > 0 ) + return pNode->Level; + if ( Abc_ObjIsCi(pNode) ) + return 0; + vSuper = (Vec_Ptr_t *)pNode->pCopy; + assert( vSuper != NULL ); + LevelMax = 0; + Vec_PtrForEachEntry( vSuper, pFanin, i ) + { + pFanin = Abc_ObjRegular(pFanin); + Abc_NtkBalanceLevel_rec(pFanin); + if ( LevelMax < (int)pFanin->Level ) + LevelMax = pFanin->Level; + } + pNode->Level = LevelMax + 1; + return pNode->Level; +} + + +/**Function************************************************************* + + Synopsis [Compute levels of implication supergates.] + + Description [] + + SideEffects [] + + SeeAlso [] + +***********************************************************************/ +void Abc_NtkBalanceLevel( Abc_Ntk_t * pNtk ) +{ + Abc_Obj_t * pNode; + int i; + Abc_NtkForEachObj( pNtk, pNode, i ) + pNode->Level = 0; + Abc_NtkForEachCo( pNtk, pNode, i ) + Abc_NtkBalanceLevel_rec( Abc_ObjFanin0(pNode) ); +} + + +/**Function************************************************************* + + Synopsis [Marks the nodes on the critical and near critical paths.] + + Description [] + + SideEffects [] + + SeeAlso [] + +***********************************************************************/ +void Abc_NtkMarkCriticalNodes( Abc_Ntk_t * pNtk ) +{ + Abc_Obj_t * pNode; + int i, Counter = 0; + Abc_NtkForEachNode( pNtk, pNode, i ) + if ( Abc_ObjRequiredLevel(pNode) - pNode->Level <= 1 ) + pNode->fMarkA = 1, Counter++; + printf( "The number of nodes on the critical paths = %6d (%5.2f %%)\n", Counter, 100.0 * Counter / Abc_NtkNodeNum(pNtk) ); +} + + +//////////////////////////////////////////////////////////////////////// +/// END OF FILE /// +//////////////////////////////////////////////////////////////////////// + + |