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-rw-r--r--src/base/abcs/abcRetime.c203
-rw-r--r--src/base/abcs/abcSeq.c644
-rw-r--r--src/base/abcs/abc_.c47
-rw-r--r--src/base/abcs/module.make2
4 files changed, 896 insertions, 0 deletions
diff --git a/src/base/abcs/abcRetime.c b/src/base/abcs/abcRetime.c
new file mode 100644
index 00000000..13b8a926
--- /dev/null
+++ b/src/base/abcs/abcRetime.c
@@ -0,0 +1,203 @@
+/**CFile****************************************************************
+
+ FileName [abcSeqRetime.c]
+
+ SystemName [ABC: Logic synthesis and verification system.]
+
+ PackageName [Network and node package.]
+
+ Synopsis [Peforms retiming for optimal clock cycle.]
+
+ Author [Alan Mishchenko]
+
+ Affiliation [UC Berkeley]
+
+ Date [Ver. 1.0. Started - June 20, 2005.]
+
+ Revision [$Id: abcSeqRetime.c,v 1.00 2005/06/20 00:00:00 alanmi Exp $]
+
+***********************************************************************/
+
+#include "abc.h"
+
+////////////////////////////////////////////////////////////////////////
+/// DECLARATIONS ///
+////////////////////////////////////////////////////////////////////////
+
+// storing arrival times in the nodes
+static inline int Abc_NodeReadLValue( Abc_Obj_t * pNode ) { return Vec_IntEntry( (pNode)->pNtk->pData, (pNode)->Id ); }
+static inline void Abc_NodeSetLValue( Abc_Obj_t * pNode, int Value ) { Vec_IntWriteEntry( (pNode)->pNtk->pData, (pNode)->Id, (Value) ); }
+
+// the internal procedures
+static int Abc_NtkRetimeSearch_rec( Abc_Ntk_t * pNtk, int FiMin, int FiMax );
+static int Abc_NtkRetimeForPeriod( Abc_Ntk_t * pNtk, int Fi );
+static int Abc_NodeUpdateLValue( Abc_Obj_t * pObj, int Fi );
+
+// node status after updating its arrival time
+enum { ABC_UPDATE_FAIL, ABC_UPDATE_NO, ABC_UPDATE_YES };
+
+////////////////////////////////////////////////////////////////////////
+/// FUNCTION DEFITIONS ///
+////////////////////////////////////////////////////////////////////////
+
+/**Function*************************************************************
+
+ Synopsis [Retimes AIG for optimal delay.]
+
+ Description []
+
+ SideEffects []
+
+ SeeAlso []
+
+***********************************************************************/
+void Abc_NtkSeqRetimeDelay( Abc_Ntk_t * pNtk )
+{
+ int FiMax, FiBest;
+ assert( Abc_NtkIsSeq( pNtk ) );
+
+ // start storage for sequential arrival times
+ assert( pNtk->pData == NULL );
+ pNtk->pData = Vec_IntAlloc( 0 );
+
+ // get the maximum possible clock
+ FiMax = Abc_NtkNodeNum(pNtk);
+
+ // make sure this clock period is feasible
+ assert( Abc_NtkRetimeForPeriod( pNtk, FiMax ) );
+
+ // search for the optimal clock period between 0 and nLevelMax
+ FiBest = Abc_NtkRetimeSearch_rec( pNtk, 0, FiMax );
+ // print the result
+ printf( "The best clock period is %3d.\n", FiBest );
+
+ // free storage
+ Vec_IntFree( pNtk->pData );
+ pNtk->pData = NULL;
+}
+
+/**Function*************************************************************
+
+ Synopsis [Performs binary search for the optimal clock period.]
+
+ Description [Assumes that FiMin is infeasible while FiMax is feasible.]
+
+ SideEffects []
+
+ SeeAlso []
+
+***********************************************************************/
+int Abc_NtkRetimeSearch_rec( Abc_Ntk_t * pNtk, int FiMin, int FiMax )
+{
+ int Median;
+
+ assert( FiMin < FiMax );
+ if ( FiMin + 1 == FiMax )
+ return FiMax;
+
+ Median = FiMin + (FiMax - FiMin)/2;
+
+ if ( Abc_NtkRetimeForPeriod( pNtk, Median ) )
+ return Abc_NtkRetimeSearch_rec( pNtk, FiMin, Median ); // Median is feasible
+ else
+ return Abc_NtkRetimeSearch_rec( pNtk, Median, FiMax ); // Median is infeasible
+}
+
+/**Function*************************************************************
+
+ Synopsis [Returns 1 if retiming with this clock period is feasible.]
+
+ Description []
+
+ SideEffects []
+
+ SeeAlso []
+
+***********************************************************************/
+int Abc_NtkRetimeForPeriod( Abc_Ntk_t * pNtk, int Fi )
+{
+ Vec_Ptr_t * vFrontier;
+ Abc_Obj_t * pObj, * pFanout;
+ int RetValue, i, k;
+
+ // set l-values of all nodes to be minus infinity
+ Vec_IntFill( pNtk->pData, Abc_NtkObjNumMax(pNtk), -ABC_INFINITY );
+
+ // start the frontier by including PI fanouts
+ vFrontier = Vec_PtrAlloc( 100 );
+ Abc_NtkForEachPi( pNtk, pObj, i )
+ {
+ Abc_NodeSetLValue( pObj, 0 );
+ Abc_ObjForEachFanout( pObj, pFanout, k )
+ if ( pFanout->fMarkA == 0 )
+ {
+ Vec_PtrPush( vFrontier, pFanout );
+ pFanout->fMarkA = 1;
+ }
+ }
+
+ // iterate until convergence
+ Vec_PtrForEachEntry( vFrontier, pObj, i )
+ {
+ RetValue = Abc_NodeUpdateLValue( pObj, Fi );
+ if ( RetValue == ABC_UPDATE_FAIL )
+ break;
+ // unmark the node as processed
+ pObj->fMarkA = 0;
+ if ( RetValue == ABC_UPDATE_NO )
+ continue;
+ assert( RetValue == ABC_UPDATE_YES );
+ // arrival times have changed - add fanouts to the frontier
+ Abc_ObjForEachFanout( pObj, pFanout, k )
+ if ( pFanout->fMarkA == 0 )
+ {
+ Vec_PtrPush( vFrontier, pFanout );
+ pFanout->fMarkA = 1;
+ }
+ }
+ // clean the nodes
+ Vec_PtrForEachEntryStart( vFrontier, pObj, k, i )
+ pObj->fMarkA = 0;
+
+ // report the results
+ if ( RetValue == ABC_UPDATE_FAIL )
+ printf( "Period = %3d. Updated nodes = %6d. Infeasible\n", Fi, vFrontier->nSize );
+ else
+ printf( "Period = %3d. Updated nodes = %6d. Feasible\n", Fi, vFrontier->nSize );
+ Vec_PtrFree( vFrontier );
+ return RetValue != ABC_UPDATE_FAIL;
+}
+
+/**Function*************************************************************
+
+ Synopsis [Computes the l-value of the node.]
+
+ Description []
+
+ SideEffects []
+
+ SeeAlso []
+
+***********************************************************************/
+int Abc_NodeUpdateLValue( Abc_Obj_t * pObj, int Fi )
+{
+ int lValueNew, lValue0, lValue1;
+ assert( !Abc_ObjIsPi(pObj) );
+ lValue0 = Abc_NodeReadLValue(Abc_ObjFanin0(pObj)) - Fi * Abc_ObjFaninL0(pObj);
+ if ( Abc_ObjFaninNum(pObj) == 2 )
+ lValue1 = Abc_NodeReadLValue(Abc_ObjFanin1(pObj)) - Fi * Abc_ObjFaninL1(pObj);
+ else
+ lValue1 = -ABC_INFINITY;
+ lValueNew = 1 + ABC_MAX( lValue0, lValue1 );
+ if ( Abc_ObjIsPo(pObj) && lValueNew > Fi )
+ return ABC_UPDATE_FAIL;
+ if ( lValueNew == Abc_NodeReadLValue(pObj) )
+ return ABC_UPDATE_NO;
+ Abc_NodeSetLValue( pObj, lValueNew );
+ return ABC_UPDATE_YES;
+}
+
+////////////////////////////////////////////////////////////////////////
+/// END OF FILE ///
+////////////////////////////////////////////////////////////////////////
+
diff --git a/src/base/abcs/abcSeq.c b/src/base/abcs/abcSeq.c
new file mode 100644
index 00000000..d6b1b8e5
--- /dev/null
+++ b/src/base/abcs/abcSeq.c
@@ -0,0 +1,644 @@
+/**CFile****************************************************************
+
+ FileName [abcSeq.c]
+
+ SystemName [ABC: Logic synthesis and verification system.]
+
+ PackageName [Network and node package.]
+
+ Synopsis []
+
+ Author [Alan Mishchenko]
+
+ Affiliation [UC Berkeley]
+
+ Date [Ver. 1.0. Started - June 20, 2005.]
+
+ Revision [$Id: abcSeq.c,v 1.00 2005/06/20 00:00:00 alanmi Exp $]
+
+***********************************************************************/
+
+#include "abc.h"
+
+/*
+ A sequential network is an AIG whose edges have number-of-latches attributes,
+ in addition to the complemented attibutes.
+
+ The sets of PIs/POs remain the same as in logic network.
+ Constant 1 node can only be used as a fanin of a PO node and the reset node.
+ The reset node produces sequence (01111...). It is used to create the
+ initialization logic of all latches.
+ The latches do not have explicit initial state but they are implicitly
+ reset by the reset node.
+
+*/
+
+////////////////////////////////////////////////////////////////////////
+/// DECLARATIONS ///
+////////////////////////////////////////////////////////////////////////
+
+static Vec_Int_t * Abc_NtkSeqCountLatches( Abc_Ntk_t * pNtk );
+static void Abc_NodeSeqCountLatches( Abc_Obj_t * pObj, Vec_Int_t * vNumbers );
+
+static void Abc_NtkSeqCreateLatches( Abc_Ntk_t * pNtk, Abc_Ntk_t * pNtkNew );
+static void Abc_NodeSeqCreateLatches( Abc_Obj_t * pObj, int nLatches );
+
+////////////////////////////////////////////////////////////////////////
+/// FUNCTION DEFITIONS ///
+////////////////////////////////////////////////////////////////////////
+
+/**Function*************************************************************
+
+ Synopsis [Converts a normal AIG into a sequential AIG.]
+
+ Description []
+
+ SideEffects []
+
+ SeeAlso []
+
+***********************************************************************/
+Abc_Ntk_t * Abc_NtkAigToSeq( Abc_Ntk_t * pNtk )
+{
+ int fCheck = 1;
+ Abc_Ntk_t * pNtkNew;
+ Abc_Aig_t * pManNew;
+ Vec_Ptr_t * vNodes;
+ Abc_Obj_t * pObj, * pConst, * pFanout, * pFaninNew, * pLatch;
+ int i, k, fChange, Counter;
+
+ assert( Abc_NtkIsStrash(pNtk) );
+ // start the network
+ pNtkNew = Abc_NtkStartFrom( pNtk, ABC_TYPE_SEQ, ABC_FUNC_AIG );
+ pManNew = pNtkNew->pManFunc;
+
+ // set mapping of the constant nodes
+ Abc_AigConst1(pNtk->pManFunc)->pCopy = Abc_AigConst1( pManNew );
+ Abc_AigReset(pNtk->pManFunc)->pCopy = Abc_AigReset( pManNew );
+
+ // get rid of initial states
+ Abc_NtkForEachLatch( pNtk, pObj, i )
+ {
+ pObj->pNext = pObj->pCopy;
+ if ( Abc_LatchIsInit0(pObj) )
+ pObj->pCopy = Abc_AigAnd( pManNew, pObj->pCopy, Abc_AigReset(pManNew) );
+ else if ( Abc_LatchIsInit1(pObj) )
+ pObj->pCopy = Abc_AigOr( pManNew, pObj->pCopy, Abc_ObjNot( Abc_AigReset(pManNew) ) );
+ }
+
+ // copy internal nodes
+ vNodes = Abc_AigDfs( pNtk, 1, 0 );
+ Vec_PtrForEachEntry( vNodes, pObj, i )
+ if ( Abc_ObjFaninNum(pObj) == 2 )
+ pObj->pCopy = Abc_AigAnd( pManNew, Abc_ObjChild0Copy(pObj), Abc_ObjChild1Copy(pObj) );
+ Vec_PtrFree( vNodes );
+
+ // relink the CO nodes
+ Abc_NtkForEachPo( pNtk, pObj, i )
+ Abc_ObjAddFanin( pObj->pCopy, Abc_ObjChild0Copy(pObj) );
+ Abc_NtkForEachLatch( pNtk, pObj, i )
+ Abc_ObjAddFanin( pObj->pNext, Abc_ObjChild0Copy(pObj) );
+
+ // propagate constant input latches in the new network
+ Counter = 0;
+ fChange = 1;
+ while ( fChange )
+ {
+ fChange = 0;
+ Abc_NtkForEachLatch( pNtkNew, pLatch, i )
+ {
+ if ( Abc_ObjFanoutNum(pLatch) == 0 )
+ continue;
+ pFaninNew = Abc_ObjFanin0(pLatch);
+ if ( Abc_ObjIsCi(pFaninNew) || !Abc_NodeIsConst(pFaninNew) )
+ continue;
+ pConst = Abc_ObjNotCond( Abc_AigConst1(pManNew), Abc_ObjFaninC0(pLatch) );
+ Abc_AigReplace( pManNew, pLatch, pConst );
+ fChange = 1;
+ Counter++;
+ }
+ }
+ if ( Counter )
+ fprintf( stdout, "Latch sweeping removed %d latches (out of %d).\n", Counter, Abc_NtkLatchNum(pNtk) );
+
+ // redirect fanouts of each latch to the latch fanins
+ vNodes = Vec_PtrAlloc( 100 );
+ Abc_NtkForEachLatch( pNtkNew, pLatch, i )
+ {
+//printf( "Latch %s. Fanouts = %d.\n", Abc_ObjName(pLatch), Abc_ObjFanoutNum(pLatch) );
+
+ Abc_NodeCollectFanouts( pLatch, vNodes );
+ Vec_PtrForEachEntry( vNodes, pFanout, k )
+ {
+ if ( Abc_ObjFaninId0(pFanout) == Abc_ObjFaninId1(pFanout))
+ printf( " ******* Identical fanins!!! ******* \n" );
+
+ if ( Abc_ObjFaninId0(pFanout) == (int)pLatch->Id )
+ {
+// pFaninNew = Abc_ObjNotCond( Abc_ObjChild0(pLatch), Abc_ObjFaninC0(pFanout) );
+ pFaninNew = Abc_ObjChild0(pLatch);
+ Abc_ObjPatchFanin( pFanout, pLatch, pFaninNew );
+ Abc_ObjAddFaninL0( pFanout, 1 );
+ }
+ else if ( Abc_ObjFaninId1(pFanout) == (int)pLatch->Id )
+ {
+// pFaninNew = Abc_ObjNotCond( Abc_ObjChild0(pLatch), Abc_ObjFaninC1(pFanout) );
+ pFaninNew = Abc_ObjChild0(pLatch);
+ Abc_ObjPatchFanin( pFanout, pLatch, pFaninNew );
+ Abc_ObjAddFaninL1( pFanout, 1 );
+ }
+ else
+ assert( 0 );
+ }
+ assert( Abc_ObjFanoutNum(pLatch) == 0 );
+ Abc_NtkDeleteObj( pLatch );
+ }
+ Vec_PtrFree( vNodes );
+ // get rid of latches altogether
+// Abc_NtkForEachLatch( pNtkNew, pObj, i )
+// Abc_NtkDeleteObj( pObj );
+ assert( pNtkNew->nLatches == 0 );
+ Vec_PtrClear( pNtkNew->vLats );
+ Vec_PtrShrink( pNtkNew->vCis, pNtk->nPis );
+ Vec_PtrShrink( pNtkNew->vCos, pNtk->nPos );
+
+/*
+/////////////////////////////////////////////
+Abc_NtkForEachNode( pNtkNew, pObj, i )
+ if ( !Abc_NodeIsConst(pObj) )
+ if ( Abc_ObjFaninL0(pObj) + Abc_ObjFaninL1(pObj) > 20 )
+ printf( "(%d,%d) ", Abc_ObjFaninL0(pObj), Abc_ObjFaninL1(pObj) );
+Abc_NtkForEachCo( pNtkNew, pObj, i )
+ printf( "(%d) ", Abc_ObjFaninL0(pObj) );
+/////////////////////////////////////////////
+printf( "\n" );
+*/
+
+ if ( pNtk->pExdc )
+ fprintf( stdout, "Warning: EXDC is dropped when converting to sequential AIG.\n" );
+ if ( fCheck && !Abc_NtkCheck( pNtkNew ) )
+ fprintf( stdout, "Abc_NtkAigToSeq(): Network check has failed.\n" );
+ return pNtkNew;
+}
+
+/**Function*************************************************************
+
+ Synopsis [Converts a sequential AIG into a logic SOP network.]
+
+ Description []
+
+ SideEffects []
+
+ SeeAlso []
+
+***********************************************************************/
+Abc_Ntk_t * Abc_NtkSeqToLogicSop( Abc_Ntk_t * pNtk )
+{
+ int fCheck = 1;
+ Abc_Ntk_t * pNtkNew;
+ Abc_Obj_t * pObj, * pFanin, * pFaninNew;
+ int i, k, c;
+ assert( Abc_NtkIsSeq(pNtk) );
+ // start the network
+ pNtkNew = Abc_NtkStartFrom( pNtk, ABC_TYPE_LOGIC, ABC_FUNC_SOP );
+ // create the constant and reset nodes
+ Abc_NtkDupConst1( pNtk, pNtkNew );
+ Abc_NtkDupReset( pNtk, pNtkNew );
+ // duplicate the nodes, create node functions and latches
+ Abc_NtkForEachNode( pNtk, pObj, i )
+ {
+ if ( Abc_NodeIsConst(pObj) )
+ continue;
+ Abc_NtkDupObj(pNtkNew, pObj);
+ pObj->pCopy->pData = Abc_SopCreateAnd2( pNtkNew->pManFunc, Abc_ObjFaninC0(pObj), Abc_ObjFaninC1(pObj) );
+ }
+ // create latches for the new nodes
+ Abc_NtkSeqCreateLatches( pNtk, pNtkNew );
+ // connect the objects
+ Abc_NtkForEachObj( pNtk, pObj, i )
+ Abc_ObjForEachFanin( pObj, pFanin, k )
+ {
+ // find the fanin
+ pFaninNew = pFanin->pCopy;
+ for ( c = 0; c < Abc_ObjFaninL(pObj, k); c++ )
+ pFaninNew = pFaninNew->pCopy;
+ Abc_ObjAddFanin( pObj->pCopy, pFaninNew );
+ }
+ // set the complemented attributed of CO edges (to be fixed by making simple COs)
+ Abc_NtkForEachPo( pNtk, pObj, i )
+ if ( Abc_ObjFaninC0(pObj) )
+ Abc_ObjSetFaninC( pObj->pCopy, 0 );
+ // fix the problem with complemented and duplicated CO edges
+ Abc_NtkLogicMakeSimpleCos( pNtkNew, 0 );
+ // duplicate the EXDC network
+ if ( pNtk->pExdc )
+ fprintf( stdout, "Warning: EXDC network is not copied.\n" );
+ if ( fCheck && !Abc_NtkCheck( pNtkNew ) )
+ fprintf( stdout, "Abc_NtkSeqToLogic(): Network check has failed.\n" );
+ return pNtkNew;
+}
+
+
+
+
+/**Function*************************************************************
+
+ Synopsis [Finds max number of latches on the fanout edges of each node.]
+
+ Description []
+
+ SideEffects []
+
+ SeeAlso []
+
+***********************************************************************/
+Vec_Int_t * Abc_NtkSeqCountLatches( Abc_Ntk_t * pNtk )
+{
+ Vec_Int_t * vNumbers;
+ Abc_Obj_t * pObj;
+ int i;
+ assert( Abc_NtkIsSeq( pNtk ) );
+ // start the array of counters
+ vNumbers = Vec_IntAlloc( 0 );
+ Vec_IntFill( vNumbers, Abc_NtkObjNumMax(pNtk), 0 );
+ // count for each edge
+ Abc_NtkForEachObj( pNtk, pObj, i )
+ Abc_NodeSeqCountLatches( pObj, vNumbers );
+ return vNumbers;
+}
+
+/**Function*************************************************************
+
+ Synopsis [Countes the latch numbers due to the fanins edges of the given node.]
+
+ Description []
+
+ SideEffects []
+
+ SeeAlso []
+
+***********************************************************************/
+void Abc_NodeSeqCountLatches( Abc_Obj_t * pObj, Vec_Int_t * vNumbers )
+{
+ Abc_Obj_t * pFanin;
+ int k, nLatches;
+ // go through each fanin edge
+ Abc_ObjForEachFanin( pObj, pFanin, k )
+ {
+ nLatches = Abc_ObjFaninL( pObj, k );
+ if ( nLatches == 0 )
+ continue;
+ if ( Vec_IntEntry( vNumbers, pFanin->Id ) < nLatches )
+ Vec_IntWriteEntry( vNumbers, pFanin->Id, nLatches );
+ }
+}
+
+
+
+/**Function*************************************************************
+
+ Synopsis [Creates latches.]
+
+ Description []
+
+ SideEffects []
+
+ SeeAlso []
+
+***********************************************************************/
+void Abc_NtkSeqCreateLatches( Abc_Ntk_t * pNtk, Abc_Ntk_t * pNtkNew )
+{
+ Vec_Int_t * vNumbers;
+ Abc_Obj_t * pObj;
+ int i;
+ assert( Abc_NtkIsSeq( pNtk ) );
+ // create latches for each new object according to the counters
+ vNumbers = Abc_NtkSeqCountLatches( pNtk );
+ Abc_NtkForEachObj( pNtk, pObj, i )
+ {
+ if ( pObj->pCopy == NULL )
+ continue;
+ Abc_NodeSeqCreateLatches( pObj->pCopy, Vec_IntEntry(vNumbers, (int)pObj->Id) );
+ }
+ Vec_IntFree( vNumbers );
+ // add latch to the PI/PO lists, create latch names
+ Abc_NtkFinalizeLatches( pNtkNew );
+}
+
+/**Function*************************************************************
+
+ Synopsis [Creates the given number of latches for this object.]
+
+ Description [The latches are attached to the node and to each other
+ through the pCopy field.]
+
+ SideEffects []
+
+ SeeAlso []
+
+***********************************************************************/
+void Abc_NodeSeqCreateLatches( Abc_Obj_t * pObj, int nLatches )
+{
+ Abc_Ntk_t * pNtk = pObj->pNtk;
+ Abc_Obj_t * pLatch, * pFanin;
+ int i;
+ pFanin = pObj;
+ for ( i = 0, pFanin = pObj; i < nLatches; pFanin = pLatch, i++ )
+ {
+ pLatch = Abc_NtkCreateLatch( pNtk );
+ Abc_LatchSetInitDc(pLatch);
+ Abc_ObjAddFanin( pLatch, pFanin );
+ pFanin->pCopy = pLatch;
+ }
+}
+
+/**Function*************************************************************
+
+ Synopsis [Counters the number of latches in the sequential AIG.]
+
+ Description []
+
+ SideEffects []
+
+ SeeAlso []
+
+***********************************************************************/
+int Abc_NtkSeqLatchNum( Abc_Ntk_t * pNtk )
+{
+ Vec_Int_t * vNumbers;
+ Abc_Obj_t * pObj;
+ int i, Counter;
+ assert( Abc_NtkIsSeq( pNtk ) );
+ // create latches for each new object according to the counters
+ Counter = 0;
+ vNumbers = Abc_NtkSeqCountLatches( pNtk );
+ Abc_NtkForEachPi( pNtk, pObj, i )
+ {
+ assert( Abc_ObjFanoutLMax(pObj) == Vec_IntEntry(vNumbers, (int)pObj->Id) );
+ Counter += Vec_IntEntry(vNumbers, (int)pObj->Id);
+ }
+ Abc_NtkForEachNode( pNtk, pObj, i )
+ {
+ if ( Abc_NodeIsConst(pObj) )
+ continue;
+ assert( Abc_ObjFanoutLMax(pObj) == Vec_IntEntry(vNumbers, (int)pObj->Id) );
+ Counter += Vec_IntEntry(vNumbers, (int)pObj->Id);
+ }
+ Vec_IntFree( vNumbers );
+ if ( Abc_ObjFanoutNum( Abc_AigReset(pNtk->pManFunc) ) > 0 )
+ Counter++;
+ return Counter;
+}
+
+
+
+
+
+
+/**Function*************************************************************
+
+ Synopsis [Performs forward retiming of the sequential AIG.]
+
+ Description []
+
+ SideEffects []
+
+ SeeAlso []
+
+***********************************************************************/
+void Abc_NtkSeqRetimeForward( Abc_Ntk_t * pNtk )
+{
+ Vec_Ptr_t * vNodes;
+ Abc_Obj_t * pNode, * pFanout;
+ int i, k, nLatches;
+ assert( Abc_NtkIsSeq( pNtk ) );
+ // assume that all nodes can be retimed
+ vNodes = Vec_PtrAlloc( 100 );
+ Abc_NtkForEachNode( pNtk, pNode, i )
+ {
+ if ( Abc_NodeIsConst(pNode) )
+ continue;
+ Vec_PtrPush( vNodes, pNode );
+ pNode->fMarkA = 1;
+ }
+ // process the nodes
+ Vec_PtrForEachEntry( vNodes, pNode, i )
+ {
+// printf( "(%d,%d) ", Abc_ObjFaninL0(pNode), Abc_ObjFaninL0(pNode) );
+ // get the number of latches to retime
+ nLatches = Abc_ObjFaninLMin(pNode);
+ if ( nLatches == 0 )
+ continue;
+ assert( nLatches > 0 );
+ // subtract these latches on the fanin side
+ Abc_ObjAddFaninL0( pNode, -nLatches );
+ Abc_ObjAddFaninL1( pNode, -nLatches );
+ // add these latches on the fanout size
+ Abc_ObjForEachFanout( pNode, pFanout, k )
+ {
+ Abc_ObjAddFanoutL( pNode, pFanout, nLatches );
+ if ( pFanout->fMarkA == 0 )
+ { // schedule the node for updating
+ Vec_PtrPush( vNodes, pFanout );
+ pFanout->fMarkA = 1;
+ }
+ }
+ // unmark the node as processed
+ pNode->fMarkA = 0;
+ }
+ Vec_PtrFree( vNodes );
+ // clean the marks
+ Abc_NtkForEachNode( pNtk, pNode, i )
+ {
+ pNode->fMarkA = 0;
+ if ( Abc_NodeIsConst(pNode) )
+ continue;
+ assert( Abc_ObjFaninLMin(pNode) == 0 );
+ }
+}
+
+/**Function*************************************************************
+
+ Synopsis [Performs forward retiming of the sequential AIG.]
+
+ Description []
+
+ SideEffects []
+
+ SeeAlso []
+
+***********************************************************************/
+void Abc_NtkSeqRetimeBackward( Abc_Ntk_t * pNtk )
+{
+ Vec_Ptr_t * vNodes;
+ Abc_Obj_t * pNode, * pFanin, * pFanout;
+ int i, k, nLatches;
+ assert( Abc_NtkIsSeq( pNtk ) );
+ // assume that all nodes can be retimed
+ vNodes = Vec_PtrAlloc( 100 );
+ Abc_NtkForEachNode( pNtk, pNode, i )
+ {
+ if ( Abc_NodeIsConst(pNode) )
+ continue;
+ Vec_PtrPush( vNodes, pNode );
+ pNode->fMarkA = 1;
+ }
+ // process the nodes
+ Vec_PtrForEachEntry( vNodes, pNode, i )
+ {
+ // get the number of latches to retime
+ nLatches = Abc_ObjFanoutLMin(pNode);
+ if ( nLatches == 0 )
+ continue;
+ assert( nLatches > 0 );
+ // subtract these latches on the fanout side
+ Abc_ObjForEachFanout( pNode, pFanout, k )
+ Abc_ObjAddFanoutL( pNode, pFanout, -nLatches );
+ // add these latches on the fanin size
+ Abc_ObjForEachFanin( pNode, pFanin, k )
+ {
+ Abc_ObjAddFaninL( pNode, k, nLatches );
+ if ( Abc_ObjIsPi(pFanin) || Abc_NodeIsConst(pFanin) )
+ continue;
+ if ( pFanin->fMarkA == 0 )
+ { // schedule the node for updating
+ Vec_PtrPush( vNodes, pFanin );
+ pFanin->fMarkA = 1;
+ }
+ }
+ // unmark the node as processed
+ pNode->fMarkA = 0;
+ }
+ Vec_PtrFree( vNodes );
+ // clean the marks
+ Abc_NtkForEachNode( pNtk, pNode, i )
+ {
+ pNode->fMarkA = 0;
+ if ( Abc_NodeIsConst(pNode) )
+ continue;
+// assert( Abc_ObjFanoutLMin(pNode) == 0 );
+ }
+}
+
+
+
+
+/**Function*************************************************************
+
+ Synopsis [Returns the latch number of the fanout.]
+
+ Description []
+
+ SideEffects []
+
+ SeeAlso []
+
+***********************************************************************/
+int Abc_ObjFanoutL( Abc_Obj_t * pObj, Abc_Obj_t * pFanout )
+{
+ assert( Abc_NtkIsSeq(pObj->pNtk) );
+ if ( Abc_ObjFaninId0(pFanout) == (int)pObj->Id )
+ return Abc_ObjFaninL0(pFanout);
+ else if ( Abc_ObjFaninId1(pFanout) == (int)pObj->Id )
+ return Abc_ObjFaninL1(pFanout);
+ else
+ assert( 0 );
+ return 0;
+}
+
+/**Function*************************************************************
+
+ Synopsis [Sets the latch number of the fanout.]
+
+ Description []
+
+ SideEffects []
+
+ SeeAlso []
+
+***********************************************************************/
+void Abc_ObjSetFanoutL( Abc_Obj_t * pObj, Abc_Obj_t * pFanout, int nLats )
+{
+ assert( Abc_NtkIsSeq(pObj->pNtk) );
+ if ( Abc_ObjFaninId0(pFanout) == (int)pObj->Id )
+ Abc_ObjSetFaninL0(pFanout, nLats);
+ else if ( Abc_ObjFaninId1(pFanout) == (int)pObj->Id )
+ Abc_ObjSetFaninL1(pFanout, nLats);
+ else
+ assert( 0 );
+}
+
+/**Function*************************************************************
+
+ Synopsis [Adds to the latch number of the fanout.]
+
+ Description []
+
+ SideEffects []
+
+ SeeAlso []
+
+***********************************************************************/
+void Abc_ObjAddFanoutL( Abc_Obj_t * pObj, Abc_Obj_t * pFanout, int nLats )
+{
+ assert( Abc_NtkIsSeq(pObj->pNtk) );
+ if ( Abc_ObjFaninId0(pFanout) == (int)pObj->Id )
+ Abc_ObjAddFaninL0(pFanout, nLats);
+ else if ( Abc_ObjFaninId1(pFanout) == (int)pObj->Id )
+ Abc_ObjAddFaninL1(pFanout, nLats);
+ else
+ assert( 0 );
+}
+
+/**Function*************************************************************
+
+ Synopsis [Returns the latch number of the fanout.]
+
+ Description []
+
+ SideEffects []
+
+ SeeAlso []
+
+***********************************************************************/
+int Abc_ObjFanoutLMax( Abc_Obj_t * pObj )
+{
+ Abc_Obj_t * pFanout;
+ int i, nLatch, nLatchRes;
+ nLatchRes = 0;
+ Abc_ObjForEachFanout( pObj, pFanout, i )
+ if ( nLatchRes < (nLatch = Abc_ObjFanoutL(pObj, pFanout)) )
+ nLatchRes = nLatch;
+ assert( nLatchRes >= 0 );
+ return nLatchRes;
+}
+
+/**Function*************************************************************
+
+ Synopsis [Returns the latch number of the fanout.]
+
+ Description []
+
+ SideEffects []
+
+ SeeAlso []
+
+***********************************************************************/
+int Abc_ObjFanoutLMin( Abc_Obj_t * pObj )
+{
+ Abc_Obj_t * pFanout;
+ int i, nLatch, nLatchRes;
+ nLatchRes = ABC_INFINITY;
+ Abc_ObjForEachFanout( pObj, pFanout, i )
+ if ( nLatchRes > (nLatch = Abc_ObjFanoutL(pObj, pFanout)) )
+ nLatchRes = nLatch;
+ assert( nLatchRes < ABC_INFINITY );
+ return nLatchRes;
+}
+
+
+////////////////////////////////////////////////////////////////////////
+/// END OF FILE ///
+////////////////////////////////////////////////////////////////////////
+
+
diff --git a/src/base/abcs/abc_.c b/src/base/abcs/abc_.c
new file mode 100644
index 00000000..bef3836f
--- /dev/null
+++ b/src/base/abcs/abc_.c
@@ -0,0 +1,47 @@
+/**CFile****************************************************************
+
+ FileName [abc_.c]
+
+ SystemName [ABC: Logic synthesis and verification system.]
+
+ PackageName [Network and node package.]
+
+ Synopsis []
+
+ Author [Alan Mishchenko]
+
+ Affiliation [UC Berkeley]
+
+ Date [Ver. 1.0. Started - June 20, 2005.]
+
+ Revision [$Id: abc_.c,v 1.00 2005/06/20 00:00:00 alanmi Exp $]
+
+***********************************************************************/
+
+#include "abc.h"
+
+////////////////////////////////////////////////////////////////////////
+/// DECLARATIONS ///
+////////////////////////////////////////////////////////////////////////
+
+////////////////////////////////////////////////////////////////////////
+/// FUNCTION DEFITIONS ///
+////////////////////////////////////////////////////////////////////////
+
+/**Function*************************************************************
+
+ Synopsis []
+
+ Description []
+
+ SideEffects []
+
+ SeeAlso []
+
+***********************************************************************/
+
+////////////////////////////////////////////////////////////////////////
+/// END OF FILE ///
+////////////////////////////////////////////////////////////////////////
+
+
diff --git a/src/base/abcs/module.make b/src/base/abcs/module.make
new file mode 100644
index 00000000..ad084bb8
--- /dev/null
+++ b/src/base/abcs/module.make
@@ -0,0 +1,2 @@
+SRC += src/base/abcs/abcRetime.c \
+ src/base/abcs/abcSeq.c