/**Function*************************************************************
Synopsis [Computes initial values of the new latches.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
Vec_Int_t * Abc_NtkRetimeInitialValues( Abc_Ntk_t * pNtkCone, Vec_Int_t * vValues, int fVerbose )
{
Vec_Int_t * vSolution;
Abc_Ntk_t * pNtkMiter, * pNtkLogic;
int RetValue;
abctime clk;
if ( pNtkCone == NULL )
return Vec_IntDup( vValues );
// convert the target network to AIG
pNtkLogic = Abc_NtkDup( pNtkCone );
Abc_NtkToAig( pNtkLogic );
// get the miter
pNtkMiter = Abc_NtkCreateTarget( pNtkLogic, pNtkLogic->vCos, vValues );
if ( fVerbose )
printf( "The miter for initial state computation has %d AIG nodes. ", Abc_NtkNodeNum(pNtkMiter) );
// solve the miter
clk = Abc_Clock();
RetValue = Abc_NtkMiterSat( pNtkMiter, (ABC_INT64_T)500000, (ABC_INT64_T)50000000, 0, NULL, NULL );
if ( fVerbose )
{ ABC_PRT( "SAT solving time", Abc_Clock() - clk ); }
// analyze the result
if ( RetValue == 1 )
printf( "Abc_NtkRetimeInitialValues(): The problem is unsatisfiable. DC latch values are used.\n" );
else if ( RetValue == -1 )
printf( "Abc_NtkRetimeInitialValues(): The SAT problem timed out. DC latch values are used.\n" );
else if ( !Abc_NtkRetimeVerifyModel( pNtkCone, vValues, pNtkMiter->pModel ) )
printf( "Abc_NtkRetimeInitialValues(): The computed counter-example is incorrect.\n" );
// set the values of the latches
vSolution = RetValue? NULL : Vec_IntAllocArray( pNtkMiter->pModel, Abc_NtkPiNum(pNtkLogic) );
pNtkMiter->pModel = NULL;
Abc_NtkDelete( pNtkMiter );
Abc_NtkDelete( pNtkLogic );
return vSolution;
}
/**Function*************************************************************
Synopsis [Implements the given retiming on the sequential AIG.]
Description [Returns 0 of initial state computation fails.]
SideEffects []
SeeAlso []
***********************************************************************/
int Seq_NtkImplementRetimingBackward( Abc_Ntk_t * pNtk, Vec_Ptr_t * vMoves, int fVerbose )
{
Seq_RetEdge_t RetEdge;
stmm_table * tTable;
stmm_generator * gen;
Vec_Int_t * vValues;
Abc_Ntk_t * pNtkProb, * pNtkMiter, * pNtkCnf;
Abc_Obj_t * pNode, * pNodeNew;
int * pModel, RetValue, i, clk;
// return if the retiming is trivial
if ( Vec_PtrSize(vMoves) == 0 )
return 1;
// create the network for the initial state computation
// start the table and the array of PO values
pNtkProb = Abc_NtkAlloc( ABC_NTK_LOGIC, ABC_FUNC_SOP, 1 );
tTable = stmm_init_table( stmm_numcmp, stmm_numhash );
vValues = Vec_IntAlloc( 100 );
// perform the backward moves and build the network for initial state computation
RetValue = 0;
Vec_PtrForEachEntry( vMoves, pNode, i )
RetValue |= Abc_ObjRetimeBackward( pNode, pNtkProb, tTable, vValues );
// add the PIs corresponding to the white spots
stmm_foreach_item( tTable, gen, (char **)&RetEdge, (char **)&pNodeNew )
Abc_ObjAddFanin( pNodeNew, Abc_NtkCreatePi(pNtkProb) );
// add the PI/PO names
Abc_NtkAddDummyPiNames( pNtkProb );
Abc_NtkAddDummyPoNames( pNtkProb );
Abc_NtkAddDummyAssertNames( pNtkProb );
// make sure everything is okay with the network structure
if ( !Abc_NtkDoCheck( pNtkProb ) )
{
printf( "Seq_NtkImplementRetimingBackward: The internal network check has failed.\n" );
Abc_NtkRetimeSetInitialValues( pNtk, tTable, NULL );
Abc_NtkDelete( pNtkProb );
stmm_free_table( tTable );
Vec_IntFree( vValues );
return 0;
}
// check if conflict is found
if ( RetValue )
{
printf( "Seq_NtkImplementRetimingBackward: A top level conflict is detected. DC latch values are used.\n" );
Abc_NtkRetimeSetInitialValues( pNtk, tTable, NULL );
Abc_NtkDelete( pNtkProb );
stmm_free_table( tTable );
Vec_IntFree( vValues );
return 0;
}
// get the miter cone
pNtkMiter = Abc_NtkCreateTarget( pNtkProb, pNtkProb->vCos, vValues );
Abc_NtkDelete( pNtkProb );
Vec_IntFree( vValues );
if ( fVerbose )
printf( "The number of ANDs in the AIG = %5d.\n", Abc_NtkNodeNum(pNtkMiter) );
// transform the miter into a logic network for efficient CNF construction
// pNtkCnf = Abc_Ntk_Renode( pNtkMiter, 0, 100, 1, 0, 0 );
// Abc_NtkDelete( pNtkMiter );
pNtkCnf = pNtkMiter;
// solve the miter
clk = clock();
// RetValue = Abc_NtkMiterSat_OldAndRusty( pNtkCnf, 30, 0 );
RetValue = Abc_NtkMiterSat( pNtkCnf, (sint64)500000, (sint64)50000000, 0, 0, NULL, NULL );
if ( fVerbose )
if ( clock() - clk > 100 )
{
PRT( "SAT solving time", clock() - clk );
}
pModel = pNtkCnf->pModel; pNtkCnf->pModel = NULL;
Abc_NtkDelete( pNtkCnf );
// analyze the result
if ( RetValue == -1 || RetValue == 1 )
{
Abc_NtkRetimeSetInitialValues( pNtk, tTable, NULL );
if ( RetValue == 1 )
printf( "Seq_NtkImplementRetimingBackward: The problem is unsatisfiable. DC latch values are used.\n" );
else
printf( "Seq_NtkImplementRetimingBackward: The SAT problem timed out. DC latch values are used.\n" );
stmm_free_table( tTable );
return 0;
}
// set the values of the latches
Abc_NtkRetimeSetInitialValues( pNtk, tTable, pModel );
stmm_free_table( tTable );
free( pModel );
return 1;
}
