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/**CFile****************************************************************
FileName [seqShare.c]
SystemName [ABC: Logic synthesis and verification system.]
PackageName [Construction and manipulation of sequential AIGs.]
Synopsis [Latch sharing at the fanout stems.]
Author [Alan Mishchenko]
Affiliation [UC Berkeley]
Date [Ver. 1.0. Started - June 20, 2005.]
Revision [$Id: seqShare.c,v 1.00 2005/06/20 00:00:00 alanmi Exp $]
***********************************************************************/
#include "seqInt.h"
////////////////////////////////////////////////////////////////////////
/// DECLARATIONS ///
////////////////////////////////////////////////////////////////////////
static void Seq_NodeShareFanouts( Abc_Obj_t * pNode, Vec_Ptr_t * vNodes );
static void Seq_NodeShareOne( Abc_Obj_t * pNode, Abc_InitType_t Init, Vec_Ptr_t * vNodes );
////////////////////////////////////////////////////////////////////////
/// FUNCTION DEFINITIONS ///
////////////////////////////////////////////////////////////////////////
/**Function*************************************************************
Synopsis [Transforms the sequential AIG to take fanout sharing into account.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Seq_NtkShareFanouts( Abc_Ntk_t * pNtk )
{
Vec_Ptr_t * vNodes;
Abc_Obj_t * pObj;
int i;
vNodes = Vec_PtrAlloc( 10 );
// share the PI latches
Abc_NtkForEachPi( pNtk, pObj, i )
Seq_NodeShareFanouts( pObj, vNodes );
// share the node latches
Abc_NtkForEachNode( pNtk, pObj, i )
Seq_NodeShareFanouts( pObj, vNodes );
Vec_PtrFree( vNodes );
}
/**Function*************************************************************
Synopsis [Transforms the node to take fanout sharing into account.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Seq_NodeShareFanouts( Abc_Obj_t * pNode, Vec_Ptr_t * vNodes )
{
Abc_Obj_t * pFanout;
Abc_InitType_t Type;
int nLatches[4], i;
// skip the node with only one fanout
if ( Abc_ObjFanoutNum(pNode) < 2 )
return;
// clean the the fanout counters
for ( i = 0; i < 4; i++ )
nLatches[i] = 0;
// find the number of fanouts having latches of each type
Abc_ObjForEachFanout( pNode, pFanout, i )
{
if ( Seq_ObjFanoutL(pNode, pFanout) == 0 )
continue;
Type = Seq_NodeGetInitLast( pFanout, Abc_ObjFanoutEdgeNum(pNode, pFanout) );
nLatches[Type]++;
}
// decide what to do
if ( nLatches[ABC_INIT_ZERO] > 1 && nLatches[ABC_INIT_ONE] > 1 ) // 0-group and 1-group
{
Seq_NodeShareOne( pNode, ABC_INIT_ZERO, vNodes ); // shares 0 and DC
Seq_NodeShareOne( pNode, ABC_INIT_ONE, vNodes ); // shares 1 and DC
}
else if ( nLatches[ABC_INIT_ZERO] > 1 ) // 0-group
Seq_NodeShareOne( pNode, ABC_INIT_ZERO, vNodes ); // shares 0 and DC
else if ( nLatches[ABC_INIT_ONE] > 1 ) // 1-group
Seq_NodeShareOne( pNode, ABC_INIT_ONE, vNodes ); // shares 1 and DC
else if ( nLatches[ABC_INIT_DC] > 1 ) // DC-group
{
if ( nLatches[ABC_INIT_ZERO] > 0 )
Seq_NodeShareOne( pNode, ABC_INIT_ZERO, vNodes ); // shares 0 and DC
else
Seq_NodeShareOne( pNode, ABC_INIT_ONE, vNodes ); // shares 1 and DC
}
}
/**Function*************************************************************
Synopsis [Transforms the node to take fanout sharing into account.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Seq_NodeShareOne( Abc_Obj_t * pNode, Abc_InitType_t Init, Vec_Ptr_t * vNodes )
{
Vec_Int_t * vNums = Seq_ObjLNums( pNode );
Vec_Ptr_t * vInits = Seq_NodeLats( pNode );
Abc_Obj_t * pFanout, * pBuffer;
Abc_InitType_t Type, InitNew;
int i;
// collect the fanouts that satisfy the property (have initial value Init or DC)
InitNew = ABC_INIT_DC;
Vec_PtrClear( vNodes );
Abc_ObjForEachFanout( pNode, pFanout, i )
{
if ( Seq_ObjFanoutL(pNode, pFanout) == 0 )
continue;
Type = Seq_NodeGetInitLast( pFanout, Abc_ObjFanoutEdgeNum(pNode, pFanout) );
if ( Type == Init )
InitNew = Init;
if ( Type == Init || Type == ABC_INIT_DC )
{
Vec_PtrPush( vNodes, pFanout );
Seq_NodeDeleteLast( pFanout, Abc_ObjFanoutEdgeNum(pNode, pFanout) );
}
}
// create the new buffer
pBuffer = Abc_NtkCreateNode( pNode->pNtk );
Abc_ObjAddFanin( pBuffer, pNode );
// grow storage for initial states
Vec_PtrGrow( vInits, 2 * pBuffer->Id + 2 );
for ( i = Vec_PtrSize(vInits); i < 2 * (int)pBuffer->Id + 2; i++ )
Vec_PtrPush( vInits, NULL );
// grow storage for numbers of latches
Vec_IntGrow( vNums, 2 * pBuffer->Id + 2 );
for ( i = Vec_IntSize(vNums); i < 2 * (int)pBuffer->Id + 2; i++ )
Vec_IntPush( vNums, 0 );
// insert the new latch
Seq_NodeInsertFirst( pBuffer, 0, InitNew );
// redirect the fanouts
Vec_PtrForEachEntry( vNodes, pFanout, i )
Abc_ObjPatchFanin( pFanout, pNode, pBuffer );
}
/**Function*************************************************************
Synopsis [Maps virtual latches into real latches.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
static inline unsigned Seq_NtkShareLatchesKey( Abc_Obj_t * pObj, Abc_InitType_t Init )
{
return (pObj->Id << 2) | Init;
}
/**Function*************************************************************
Synopsis [Maps virtual latches into real latches.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
Abc_Obj_t * Seq_NtkShareLatches_rec( Abc_Ntk_t * pNtk, Abc_Obj_t * pObj, Seq_Lat_t * pRing, int nLatch, stmm_table * tLatchMap )
{
Abc_Obj_t * pLatch, * pFanin;
Abc_InitType_t Init;
unsigned Key;
if ( nLatch == 0 )
return pObj;
assert( pRing->pLatch == NULL );
// get the latch on the previous level
pFanin = Seq_NtkShareLatches_rec( pNtk, pObj, Seq_LatNext(pRing), nLatch - 1, tLatchMap );
// get the initial state
Init = Seq_LatInit( pRing );
// check if the latch with this initial state exists
Key = Seq_NtkShareLatchesKey( pFanin, Init );
if ( stmm_lookup( tLatchMap, (char *)Key, (char **)&pLatch ) )
return pRing->pLatch = pLatch;
// does not exist
if ( Init != ABC_INIT_DC )
{
// check if the don't-care exists
Key = Seq_NtkShareLatchesKey( pFanin, ABC_INIT_DC );
if ( stmm_lookup( tLatchMap, (char *)Key, (char **)&pLatch ) ) // yes
{
// update the table
stmm_delete( tLatchMap, (char **)&Key, (char **)&pLatch );
Key = Seq_NtkShareLatchesKey( pFanin, Init );
stmm_insert( tLatchMap, (char *)Key, (char *)pLatch );
// change don't-care to the given value
pLatch->pData = (void *)Init;
return pRing->pLatch = pLatch;
}
// add the latch with this value
pLatch = Abc_NtkCreateLatch( pNtk );
pLatch->pData = (void *)Init;
Abc_ObjAddFanin( pLatch, pFanin );
// add it to the table
Key = Seq_NtkShareLatchesKey( pFanin, Init );
stmm_insert( tLatchMap, (char *)Key, (char *)pLatch );
return pRing->pLatch = pLatch;
}
// the init value is the don't-care
// check if care values exist
Key = Seq_NtkShareLatchesKey( pFanin, ABC_INIT_ZERO );
if ( stmm_lookup( tLatchMap, (char *)Key, (char **)&pLatch ) )
{
Seq_LatSetInit( pRing, ABC_INIT_ZERO );
return pRing->pLatch = pLatch;
}
Key = Seq_NtkShareLatchesKey( pFanin, ABC_INIT_ONE );
if ( stmm_lookup( tLatchMap, (char *)Key, (char **)&pLatch ) )
{
Seq_LatSetInit( pRing, ABC_INIT_ONE );
return pRing->pLatch = pLatch;
}
// create the don't-care latch
pLatch = Abc_NtkCreateLatch( pNtk );
pLatch->pData = (void *)ABC_INIT_DC;
Abc_ObjAddFanin( pLatch, pFanin );
// add it to the table
Key = Seq_NtkShareLatchesKey( pFanin, ABC_INIT_DC );
stmm_insert( tLatchMap, (char *)Key, (char *)pLatch );
return pRing->pLatch = pLatch;
}
/**Function*************************************************************
Synopsis [Maps virtual latches into real latches.]
Description [Creates new latches and assigns them to virtual latches
on the edges of a sequential AIG. The nodes of the new network should
be created before this procedure is called.]
SideEffects []
SeeAlso []
***********************************************************************/
void Seq_NtkShareLatches( Abc_Ntk_t * pNtkNew, Abc_Ntk_t * pNtk )
{
Abc_Obj_t * pObj, * pFanin;
stmm_table * tLatchMap;
int i;
assert( Abc_NtkIsSeq( pNtk ) );
tLatchMap = stmm_init_table( stmm_ptrcmp, stmm_ptrhash );
Abc_AigForEachAnd( pNtk, pObj, i )
{
pFanin = Abc_ObjFanin0(pObj);
Seq_NtkShareLatches_rec( pNtkNew, pFanin->pCopy, Seq_NodeGetRing(pObj,0), Seq_NodeCountLats(pObj,0), tLatchMap );
pFanin = Abc_ObjFanin1(pObj);
Seq_NtkShareLatches_rec( pNtkNew, pFanin->pCopy, Seq_NodeGetRing(pObj,1), Seq_NodeCountLats(pObj,1), tLatchMap );
}
Abc_NtkForEachPo( pNtk, pObj, i )
Seq_NtkShareLatches_rec( pNtkNew, Abc_ObjFanin0(pObj)->pCopy, Seq_NodeGetRing(pObj,0), Seq_NodeCountLats(pObj,0), tLatchMap );
stmm_free_table( tLatchMap );
}
/**Function*************************************************************
Synopsis [Maps virtual latches into real latches.]
Description [Creates new latches and assigns them to virtual latches
on the edges of a sequential AIG. The nodes of the new network should
be created before this procedure is called.]
SideEffects []
SeeAlso []
***********************************************************************/
void Seq_NtkShareLatchesMapping( Abc_Ntk_t * pNtkNew, Abc_Ntk_t * pNtk, Vec_Ptr_t * vMapAnds, int fFpga )
{
Seq_Match_t * pMatch;
Abc_Obj_t * pObj, * pFanout;
stmm_table * tLatchMap;
Vec_Ptr_t * vNodes;
int i, k;
assert( Abc_NtkIsSeq( pNtk ) );
// start the table
tLatchMap = stmm_init_table( stmm_ptrcmp, stmm_ptrhash );
// create the array of all nodes with sharable fanouts
vNodes = Vec_PtrAlloc( 100 );
Vec_PtrPush( vNodes, Abc_NtkConst1(pNtk) );
Abc_NtkForEachPi( pNtk, pObj, i )
Vec_PtrPush( vNodes, pObj );
if ( fFpga )
{
Vec_PtrForEachEntry( vMapAnds, pObj, i )
Vec_PtrPush( vNodes, pObj );
}
else
{
Vec_PtrForEachEntry( vMapAnds, pMatch, i )
Vec_PtrPush( vNodes, pMatch->pAnd );
}
// process nodes used in the mapping
Vec_PtrForEachEntry( vNodes, pObj, i )
{
// make sure the label is clean
Abc_ObjForEachFanout( pObj, pFanout, k )
assert( pFanout->fMarkC == 0 );
Abc_ObjForEachFanout( pObj, pFanout, k )
{
if ( pFanout->fMarkC )
continue;
pFanout->fMarkC = 1;
if ( Abc_ObjFaninId0(pFanout) == pObj->Id )
Seq_NtkShareLatches_rec( pNtkNew, pObj->pCopy, Seq_NodeGetRing(pFanout,0), Seq_NodeCountLats(pFanout,0), tLatchMap );
if ( Abc_ObjFaninId1(pFanout) == pObj->Id )
Seq_NtkShareLatches_rec( pNtkNew, pObj->pCopy, Seq_NodeGetRing(pFanout,1), Seq_NodeCountLats(pFanout,1), tLatchMap );
}
// clean the label
Abc_ObjForEachFanout( pObj, pFanout, k )
pFanout->fMarkC = 0;
}
stmm_free_table( tLatchMap );
// return to the old array
Vec_PtrFree( vNodes );
}
/**Function*************************************************************
Synopsis [Clean the latches after sharing them.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Seq_NtkShareLatchesClean( Abc_Ntk_t * pNtk )
{
Abc_Obj_t * pObj;
int i;
assert( Abc_NtkIsSeq( pNtk ) );
Abc_AigForEachAnd( pNtk, pObj, i )
{
Seq_NodeCleanLats( pObj, 0 );
Seq_NodeCleanLats( pObj, 1 );
}
Abc_NtkForEachPo( pNtk, pObj, i )
Seq_NodeCleanLats( pObj, 0 );
}
////////////////////////////////////////////////////////////////////////
/// END OF FILE ///
////////////////////////////////////////////////////////////////////////
|
