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/**CFile****************************************************************
FileName [mfsResub.c]
SystemName [ABC: Logic synthesis and verification system.]
PackageName [The good old minimization with complete don't-cares.]
Synopsis [Procedures to perform resubstitution.]
Author [Alan Mishchenko]
Affiliation [UC Berkeley]
Date [Ver. 1.0. Started - June 20, 2005.]
Revision [$Id: mfsResub.c,v 1.00 2005/06/20 00:00:00 alanmi Exp $]
***********************************************************************/
#include "mfsInt.h"
////////////////////////////////////////////////////////////////////////
/// DECLARATIONS ///
////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////
/// FUNCTION DEFINITIONS ///
////////////////////////////////////////////////////////////////////////
/**Function*************************************************************
Synopsis [Updates the network after resubstitution.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Abc_NtkMfsUpdateNetwork( Mfs_Man_t * p, Abc_Obj_t * pObj, Vec_Ptr_t * vFanins, Hop_Obj_t * pFunc )
{
Abc_Obj_t * pObjNew, * pFanin;
int k;
// create the new node
pObjNew = Abc_NtkCreateNode( pObj->pNtk );
pObjNew->pData = pFunc;
Vec_PtrForEachEntry( vFanins, pFanin, k )
Abc_ObjAddFanin( pObjNew, pFanin );
// replace the old node by the new node
//printf( "Replacing node " ); Abc_ObjPrint( stdout, pObj );
//printf( "Inserting node " ); Abc_ObjPrint( stdout, pObjNew );
// update the level of the node
Abc_NtkUpdate( pObj, pObjNew, p->vLevels );
}
/**Function*************************************************************
Synopsis [Tries resubstitution.]
Description [Returns 1 if it is feasible, or 0 if c-ex is found.]
SideEffects []
SeeAlso []
***********************************************************************/
int Abc_NtkMfsTryResubOnce( Mfs_Man_t * p, int * pCands, int nCands )
{
unsigned * pData, * pDataTot;
int RetValue, iVar, i;
p->nSatCalls++;
RetValue = sat_solver_solve( p->pSat, pCands, pCands + nCands, (sint64)0, (sint64)0, (sint64)0, (sint64)0 );
assert( RetValue == l_False || RetValue == l_True );
if ( RetValue == l_False )
return 1;
p->nSatCexes++;
// store the counter-example
pData = Vec_PtrEntry( p->vDivCexes, p->nCexes++ );
assert( pData[0] == 0 );
Vec_IntForEachEntry( p->vProjVars, iVar, i )
{
if ( sat_solver_var_value( p->pSat, iVar ) )
Aig_InfoSetBit( pData, i );
}
// AND the result with the previous ones
pDataTot = Vec_PtrEntry( p->vDivCexes, Vec_PtrSize(p->vDivs) );
for ( i = 0; i < p->nDivWords; i++ )
pDataTot[i] &= pData[i];
return 0;
}
/**Function*************************************************************
Synopsis [Performs resubstitution for the node.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int Abc_NtkMfsSolveSatResub( Mfs_Man_t * p, Abc_Obj_t * pNode, int iFanin, int fOnlyRemove )
{
int fVeryVerbose = p->pPars->fVeryVerbose && Vec_PtrSize(p->vDivs) < 80;
unsigned * pData;
int pCands[MFS_FANIN_MAX];
int iVar, i, nCands, clk;
Abc_Obj_t * pFanin;
Hop_Obj_t * pFunc;
assert( iFanin >= 0 );
// clean simulation info
Vec_PtrCleanSimInfo( p->vDivCexes, 0, p->nDivWords );
pData = Vec_PtrEntry( p->vDivCexes, Vec_PtrSize(p->vDivs) );
memset( pData, 0xFF, sizeof(unsigned) * p->nDivWords );
p->nCexes = 0;
if ( fVeryVerbose )
{
printf( "\n" );
printf( "Node %5d : Level = %2d. Divs = %3d. Fanin = %d (out of %d). MFFC = %d\n",
pNode->Id, pNode->Level, Vec_PtrSize(p->vDivs)-Abc_ObjFaninNum(pNode),
iFanin, Abc_ObjFaninNum(pNode),
Abc_ObjFanoutNum(Abc_ObjFanin(pNode, iFanin)) == 1 ? Abc_NodeMffcLabel(Abc_ObjFanin(pNode, iFanin)) : 0 );
}
// try fanins without the critical fanin
nCands = 0;
Vec_PtrClear( p->vFanins );
Abc_ObjForEachFanin( pNode, pFanin, i )
{
if ( i == iFanin )
continue;
Vec_PtrPush( p->vFanins, pFanin );
iVar = Vec_PtrSize(p->vDivs) - Abc_ObjFaninNum(pNode) + i;
pCands[nCands++] = toLitCond( Vec_IntEntry( p->vProjVars, iVar ), 1 );
}
if ( Abc_NtkMfsTryResubOnce( p, pCands, nCands ) )
{
if ( fVeryVerbose )
printf( "Node %d: Fanin %d can be removed.\n", pNode->Id, iFanin );
p->nNodesResub++;
// p->nNodesGained += Abc_NodeMffcLabel(pNode);
clk = clock();
// derive the function
pFunc = Abc_NtkMfsInterplate( p, pCands, nCands );
// update the network
Abc_NtkMfsUpdateNetwork( p, pNode, p->vFanins, pFunc );
p->timeInt += clock() - clk;
return 1;
}
if ( fOnlyRemove )
return 0;
// shift variables by 1
for ( i = Vec_PtrSize(p->vFanins); i > 0; i-- )
p->vFanins->pArray[i] = p->vFanins->pArray[i-1];
p->vFanins->nSize++;
if ( fVeryVerbose )
{
for ( i = 0; i < 8; i++ )
printf( " " );
for ( i = 0; i < Vec_PtrSize(p->vDivs)-Abc_ObjFaninNum(pNode); i++ )
printf( "%d", i % 10 );
for ( i = 0; i < Abc_ObjFaninNum(pNode); i++ )
if ( i == iFanin )
printf( "*" );
else
printf( "%c", 'a' + i );
printf( "\n" );
}
iVar = -1;
while ( 1 )
{
if ( fVeryVerbose )
{
printf( "%3d: %2d ", p->nCexes, iVar );
pData = Vec_PtrEntry( p->vDivCexes, p->nCexes-1 );
// Extra_PrintBinary( stdout, pData, Vec_PtrSize(p->vDivs) );
for ( i = 0; i < Vec_PtrSize(p->vDivs); i++ )
printf( "%d", Aig_InfoHasBit(pData, i) );
printf( "\n" );
}
// find the next divisor to try
pData = Vec_PtrEntry( p->vDivCexes, Vec_PtrSize(p->vDivs) );
for ( iVar = 0; iVar < Vec_PtrSize(p->vDivs)-Abc_ObjFaninNum(pNode); iVar++ )
if ( Aig_InfoHasBit( pData, iVar ) )
break;
if ( iVar == Vec_PtrSize(p->vDivs)-Abc_ObjFaninNum(pNode) )
return 0;
pCands[nCands] = toLitCond( Vec_IntEntry(p->vProjVars, iVar), 1 );
if ( Abc_NtkMfsTryResubOnce( p, pCands, nCands+1 ) )
{
if ( fVeryVerbose )
printf( "Node %d: Fanin %d can be replaced by divisor %d.\n", pNode->Id, iFanin, iVar );
p->nNodesResub++;
// p->nNodesGained += Abc_NodeMffcLabel(pNode);
clk = clock();
// derive the function
pFunc = Abc_NtkMfsInterplate( p, pCands, nCands+1 );
// update the network
// Vec_PtrPush( p->vFanins, Vec_PtrEntry(p->vDivs, iVar) );
Vec_PtrWriteEntry( p->vFanins, 0, Vec_PtrEntry(p->vDivs, iVar) );
Abc_NtkMfsUpdateNetwork( p, pNode, p->vFanins, pFunc );
p->timeInt += clock() - clk;
return 1;
}
}
return 0;
}
/**Function*************************************************************
Synopsis [Performs resubstitution for the node.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int Abc_NtkMfsResubArea( Mfs_Man_t * p, Abc_Obj_t * pNode )
{
Abc_Obj_t * pFanin;
int i;
Abc_ObjForEachFanin( pNode, pFanin, i )
if ( !Abc_ObjIsCi(pFanin) && Abc_ObjFanoutNum(pFanin) == 1 )
{
if ( Abc_NtkMfsSolveSatResub( p, pNode, i, 0 ) )
return 1;
}
return 0;
}
/**Function*************************************************************
Synopsis [Performs resubstitution for the node.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int Abc_NtkMfsResubEdge( Mfs_Man_t * p, Abc_Obj_t * pNode )
{
Abc_Obj_t * pFanin;
int i;
Abc_ObjForEachFanin( pNode, pFanin, i )
if ( !Abc_ObjIsCi(pFanin) && Abc_ObjFanoutNum(pFanin) == 1 )
{
if ( Abc_NtkMfsSolveSatResub( p, pNode, i, 0 ) )
return 1;
}
Abc_ObjForEachFanin( pNode, pFanin, i )
if ( !Abc_ObjIsCi(pFanin) && Abc_ObjFanoutNum(pFanin) != 1 )
{
if ( Abc_NtkMfsSolveSatResub( p, pNode, i, 1 ) )
return 1;
}
return 0;
}
////////////////////////////////////////////////////////////////////////
/// END OF FILE ///
////////////////////////////////////////////////////////////////////////
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