retInt.h File Reference

#include "base/abc/abc.h"

Go to the source code of this file.

Functions
ABC_NAMESPACE_HEADER_START int	Abc_NtkRetimeMinArea (Abc_Ntk_t *pNtk, int fForwardOnly, int fBackwardOnly, int fVerbose)
	INCLUDES ///. More...
int	Abc_NtkRetime (Abc_Ntk_t *pNtk, int Mode, int nDelayLim, int fForwardOnly, int fBackwardOnly, int fOneStep, int fVerbose)
	FUNCTION DEFINITIONS ///. More...
int	Abc_NtkRetimeMinDelay (Abc_Ntk_t *pNtk, Abc_Ntk_t *pNtkCopy, int nDelayLim, int nIterLimit, int fForward, int fVerbose)
	FUNCTION DEFINITIONS ///. More...
int	Abc_NtkRetimeIncremental (Abc_Ntk_t *pNtk, int nDelayLim, int fForward, int fMinDelay, int fOneStep, int fVerbose)
	FUNCTION DEFINITIONS ///. More...
void	Abc_NtkRetimeShareLatches (Abc_Ntk_t *pNtk, int fInitial)
int	Abc_NtkRetimeNodeIsEnabled (Abc_Obj_t *pObj, int fForward)
void	Abc_NtkRetimeNode (Abc_Obj_t *pObj, int fForward, int fInitial)
st__table *	Abc_NtkRetimePrepareLatches (Abc_Ntk_t *pNtk)
int	Abc_NtkRetimeFinalizeLatches (Abc_Ntk_t *pNtk, st__table *tLatches, int nIdMaxStart)
void	Abc_NtkMaxFlowTest (Abc_Ntk_t *pNtk)
	FUNCTION DEFINITIONS ///. More...
Vec_Ptr_t *	Abc_NtkMaxFlow (Abc_Ntk_t *pNtk, int fForward, int fVerbose)
Vec_Int_t *	Abc_NtkRetimeInitialValues (Abc_Ntk_t *pNtkSat, Vec_Int_t *vValues, int fVerbose)
	FUNCTION DEFINITIONS ///. More...
int	Abc_ObjSopSimulate (Abc_Obj_t *pObj)
void	Abc_NtkRetimeTranferToCopy (Abc_Ntk_t *pNtk)
void	Abc_NtkRetimeTranferFromCopy (Abc_Ntk_t *pNtk)
Vec_Int_t *	Abc_NtkRetimeCollectLatchValues (Abc_Ntk_t *pNtk)
void	Abc_NtkRetimeInsertLatchValues (Abc_Ntk_t *pNtk, Vec_Int_t *vValues)
Abc_Ntk_t *	Abc_NtkRetimeBackwardInitialStart (Abc_Ntk_t *pNtk)
void	Abc_NtkRetimeBackwardInitialFinish (Abc_Ntk_t *pNtk, Abc_Ntk_t *pNtkNew, Vec_Int_t *vValuesOld, int fVerbose)
int	Abc_NtkRetimeLValue (Abc_Ntk_t *pNtk, int nIterLimit, int fVerbose)
	FUNCTION DEFINITIONS ///. More...

Function Documentation

Vec_Ptr_t* Abc_NtkMaxFlow	(	Abc_Ntk_t *	pNtk,
		int	fForward,
		int	fVerbose
	)

Function*************************************************************

Synopsis [Implementation of max-flow/min-cut computation.]

Description []

SideEffects []

SeeAlso []

Definition at line 143 of file retFlow.c.

{
    Vec_Ptr_t * vMinCut;
    Abc_Obj_t * pLatch;
    int Flow, FlowCur, RetValue, i;
    abctime clk = Abc_Clock();
    int fUseDirectedFlow = 1;

    // find the max-flow
    Abc_NtkCleanCopy( pNtk );
    Flow = 0;
    Abc_NtkIncrementTravId(pNtk);
    Abc_NtkForEachLatch( pNtk, pLatch, i )
    {
        if ( fForward )
        {
//            assert( !Abc_ObjFanout0(pLatch)->fMarkA );
            FlowCur  = Abc_NtkMaxFlowFwdPath2_rec( Abc_ObjFanout0(pLatch) );
//            FlowCur  = Abc_NtkMaxFlowFwdPath3_rec( Abc_ObjFanout0(pLatch), pLatch, 1 );
            Flow    += FlowCur;
        }
        else
        {
            assert( !Abc_ObjFanin0(pLatch)->fMarkA );
            FlowCur  = Abc_NtkMaxFlowBwdPath2_rec( Abc_ObjFanin0(pLatch) );
            Flow    += FlowCur;
        }
        if ( FlowCur )
            Abc_NtkIncrementTravId(pNtk);
    }

    if ( !fUseDirectedFlow )
    {
        Abc_NtkIncrementTravId(pNtk);
        Abc_NtkForEachLatch( pNtk, pLatch, i )
        {
            if ( fForward )
            {
    //            assert( !Abc_ObjFanout0(pLatch)->fMarkA );
                FlowCur  = Abc_NtkMaxFlowFwdPath_rec( Abc_ObjFanout0(pLatch) );
                Flow    += FlowCur;
            }
            else
            {
                assert( !Abc_ObjFanin0(pLatch)->fMarkA );
                FlowCur  = Abc_NtkMaxFlowBwdPath_rec( Abc_ObjFanin0(pLatch) );
                Flow    += FlowCur;
            }
            if ( FlowCur )
                Abc_NtkIncrementTravId(pNtk);
        }
    }
//    Abc_NtkMaxFlowPrintFlow( pNtk, fForward );

    // mark the nodes reachable from the latches
    Abc_NtkIncrementTravId(pNtk);
    Abc_NtkForEachLatch( pNtk, pLatch, i )
    {
        if ( fForward )
        {
//            assert( !Abc_ObjFanout0(pLatch)->fMarkA );
            if ( fUseDirectedFlow )
                RetValue = Abc_NtkMaxFlowFwdPath2_rec( Abc_ObjFanout0(pLatch) );
//                RetValue = Abc_NtkMaxFlowFwdPath3_rec( Abc_ObjFanout0(pLatch), pLatch, 1 );
            else
                RetValue = Abc_NtkMaxFlowFwdPath_rec( Abc_ObjFanout0(pLatch) );
        }
        else
        {
            assert( !Abc_ObjFanin0(pLatch)->fMarkA );
            if ( fUseDirectedFlow )
                RetValue = Abc_NtkMaxFlowBwdPath2_rec( Abc_ObjFanin0(pLatch) );
            else
                RetValue = Abc_NtkMaxFlowBwdPath_rec( Abc_ObjFanin0(pLatch) );
        }
        assert( RetValue == 0 );
    }

    // find the min-cut with the smallest volume
    vMinCut = Abc_NtkMaxFlowMinCut( pNtk, fForward );
    // verify the cut
    if ( !Abc_NtkMaxFlowVerifyCut(pNtk, vMinCut, fForward) )
        printf( "Abc_NtkMaxFlow() error! The computed min-cut is not a cut!\n" );
    // make the cut retimable
    Abc_NtkMaxFlowMinCutUpdate( pNtk, vMinCut, fForward );

    // report the results
    if ( fVerbose )
    {
    printf( "L = %6d. %s max-flow = %6d.  Min-cut = %6d.  ", 
        Abc_NtkLatchNum(pNtk), fForward? "Forward " : "Backward", Flow, Vec_PtrSize(vMinCut) );
ABC_PRT( "Time", Abc_Clock() - clk );
    }

//    Abc_NtkMaxFlowPrintCut( pNtk, vMinCut );
    return vMinCut;
}

void Abc_NtkMaxFlowTest

(

Abc_Ntk_t *

pNtk

)

FUNCTION DEFINITIONS ///.

Function*************************************************************

Synopsis [Test-bench for the max-flow computation.]

Description []

SideEffects []

SeeAlso []

Definition at line 104 of file retFlow.c.

{
    Vec_Ptr_t * vMinCut;
    Abc_Obj_t * pObj;
    int i;

    // forward flow
    Abc_NtkForEachPo( pNtk, pObj, i )
        pObj->fMarkA = 1;
    Abc_NtkForEachLatch( pNtk, pObj, i )
        pObj->fMarkA = Abc_ObjFanin0(pObj)->fMarkA = 1;
//        Abc_ObjFanin0(pObj)->fMarkA = 1;
    vMinCut = Abc_NtkMaxFlow( pNtk, 1, 1 );
    Vec_PtrFree( vMinCut );
    Abc_NtkCleanMarkA( pNtk );

    // backward flow
    Abc_NtkForEachPi( pNtk, pObj, i )
        pObj->fMarkA = 1;
    Abc_NtkForEachLatch( pNtk, pObj, i )
        pObj->fMarkA = Abc_ObjFanout0(pObj)->fMarkA = 1;
//        Abc_ObjFanout0(pObj)->fMarkA = 1;
    vMinCut = Abc_NtkMaxFlow( pNtk, 0, 1 );
    Vec_PtrFree( vMinCut );
    Abc_NtkCleanMarkA( pNtk );

}

int Abc_NtkRetime	(	Abc_Ntk_t *	pNtk,
		int	Mode,
		int	nDelayLim,
		int	fForwardOnly,
		int	fBackwardOnly,
		int	fOneStep,
		int	fVerbose
	)

FUNCTION DEFINITIONS ///.

Function*************************************************************

Synopsis [Implementation of retiming.]

Description []

SideEffects []

SeeAlso []

Definition at line 47 of file retCore.c.

{
    int nLatches = Abc_NtkLatchNum(pNtk);
    int nLevels  = Abc_NtkLevel(pNtk);
    int RetValue = 0;
    abctime clkTotal = Abc_Clock();
    int nNodesOld, nLatchesOld;
    assert( Mode > 0 && Mode < 7 );
    assert( !fForwardOnly || !fBackwardOnly );

    // cleanup the network
    nNodesOld   = Abc_NtkNodeNum(pNtk);
    nLatchesOld = Abc_NtkLatchNum(pNtk);
    Abc_NtkCleanupSeq(pNtk, 0, 0, 0);
    if ( nNodesOld > Abc_NtkNodeNum(pNtk) || nLatchesOld > Abc_NtkLatchNum(pNtk) )
        printf( "Cleanup before retiming removed %d dangling nodes and %d dangling latches.\n",
            nNodesOld - Abc_NtkNodeNum(pNtk), nLatchesOld - Abc_NtkLatchNum(pNtk) );

    // perform retiming
    switch ( Mode )
    {
    case 1: // forward 
        RetValue = Abc_NtkRetimeIncremental( pNtk, nDelayLim, 1, 0, 0, fVerbose );
        break;
    case 2: // backward 
        RetValue = Abc_NtkRetimeIncremental( pNtk, nDelayLim, 0, 0, 0, fVerbose );
        break;
    case 3: // min-area 
        RetValue = Abc_NtkRetimeMinArea( pNtk, fForwardOnly, fBackwardOnly, fVerbose );
        break;
    case 4: // min-delay
        if ( !fBackwardOnly )
            RetValue += Abc_NtkRetimeIncremental( pNtk, nDelayLim, 1, 1, fOneStep, fVerbose );
        if ( !fForwardOnly )
            RetValue += Abc_NtkRetimeIncremental( pNtk, nDelayLim, 0, 1, fOneStep, fVerbose );
        break;
    case 5: // min-area + min-delay
        RetValue  = Abc_NtkRetimeMinArea( pNtk, fForwardOnly, fBackwardOnly, fVerbose );
        if ( !fBackwardOnly )
            RetValue += Abc_NtkRetimeIncremental( pNtk, nDelayLim, 1, 1, 0, fVerbose );
        if ( !fForwardOnly )
            RetValue += Abc_NtkRetimeIncremental( pNtk, nDelayLim, 0, 1, 0, fVerbose );
        break;
    case 6: // Pan's algorithm
        RetValue = Abc_NtkRetimeLValue( pNtk, 500, fVerbose );
        break;
    default:
        printf( "Unknown retiming option.\n" );
        break;
    }
    if ( fVerbose )
    {
        printf( "Reduction in area = %3d. Reduction in delay = %3d. ", 
            nLatches - Abc_NtkLatchNum(pNtk), nLevels - Abc_NtkLevel(pNtk) );
        ABC_PRT( "Total runtime", Abc_Clock() - clkTotal );
    }
    timeRetime = Abc_Clock() - clkTotal;
    return RetValue;
}

void Abc_NtkRetimeBackwardInitialFinish	(	Abc_Ntk_t *	pNtk,
		Abc_Ntk_t *	pNtkNew,
		Vec_Int_t *	vValuesOld,
		int	fVerbose
	)

Function*************************************************************

Synopsis [Transfer latch initial values to pCopy.]

Description []

SideEffects []

SeeAlso []

Definition at line 279 of file retInit.c.

{
    Vec_Int_t * vValuesNew;
    Abc_Obj_t * pObj;
    int i;
    // create PIs corresponding to the initial values
    Abc_NtkForEachObj( pNtk, pObj, i )
        if ( Abc_ObjIsLatch(pObj) )
            Abc_ObjAddFanin( pObj->pCopy, Abc_NtkCreatePi(pNtkNew) );
    // assign dummy node names
    Abc_NtkAddDummyPiNames( pNtkNew );
    Abc_NtkAddDummyPoNames( pNtkNew );
    // check the network
    if ( !Abc_NtkCheck( pNtkNew ) )
        fprintf( stdout, "Abc_NtkRetimeBackwardInitialFinish(): Network check has failed.\n" );
    // derive new initial values
    vValuesNew = Abc_NtkRetimeInitialValues( pNtkNew, vValuesOld, fVerbose );
    // insert new initial values
    Abc_NtkRetimeInsertLatchValues( pNtk, vValuesNew );
    if ( vValuesNew ) Vec_IntFree( vValuesNew );
}

Abc_Ntk_t* Abc_NtkRetimeBackwardInitialStart

(

Abc_Ntk_t *

pNtk

)

Function*************************************************************

Synopsis [Transfer latch initial values to pCopy.]

Description []

SideEffects []

SeeAlso []

Definition at line 254 of file retInit.c.

{
    Abc_Ntk_t * pNtkNew;
    Abc_Obj_t * pObj;
    int i;
    // create the network used for the initial state computation
    pNtkNew = Abc_NtkAlloc( ABC_NTK_LOGIC, ABC_FUNC_SOP, 1 );
    // create POs corresponding to the initial values
    Abc_NtkForEachObj( pNtk, pObj, i )
        if ( Abc_ObjIsLatch(pObj) )
            pObj->pCopy = Abc_NtkCreatePo(pNtkNew);
    return pNtkNew;
}

Vec_Int_t* Abc_NtkRetimeCollectLatchValues

(

Abc_Ntk_t *

pNtk

)

Function*************************************************************

Synopsis [Transfer latch initial values to pCopy.]

Description []

SideEffects []

SeeAlso []

Definition at line 208 of file retInit.c.

{
    Vec_Int_t * vValues;
    Abc_Obj_t * pObj;
    int i;
    vValues = Vec_IntAlloc( Abc_NtkLatchNum(pNtk) );
    Abc_NtkForEachObj( pNtk, pObj, i )
        if ( Abc_ObjIsLatch(pObj) )
            Vec_IntPush( vValues, Abc_LatchIsInit1(pObj) );
    return vValues;
}

int Abc_NtkRetimeFinalizeLatches	(	Abc_Ntk_t *	pNtk,
		st__table *	tLatches,
		int	nIdMaxStart
	)

Function*************************************************************

Synopsis [Finalizes the latches after retiming.]

Description [Reuses the LIs/LOs for old latches.]

SideEffects []

SeeAlso []

Definition at line 146 of file retIncrem.c.

{
    Vec_Ptr_t * vCisOld, * vCosOld, * vBoxesOld, * vCisNew, * vCosNew, * vBoxesNew;
    Abc_Obj_t * pObj, * pLatch, * pLatchIn, * pLatchOut;
    int i, Index;
    // create new arrays
    vCisOld   = pNtk->vCis;    pNtk->vCis   = NULL;  vCisNew   = Vec_PtrAlloc( 100 );
    vCosOld   = pNtk->vCos;    pNtk->vCos   = NULL;  vCosNew   = Vec_PtrAlloc( 100 );  
    vBoxesOld = pNtk->vBoxes;  pNtk->vBoxes = NULL;  vBoxesNew = Vec_PtrAlloc( 100 );
    // copy boxes and their CIs/COs
    Vec_PtrForEachEntryStop( Abc_Obj_t *, vCisOld, pObj, i, Vec_PtrSize(vCisOld) - st__count(tLatches) )
        Vec_PtrPush( vCisNew, pObj );
    Vec_PtrForEachEntryStop( Abc_Obj_t *, vCosOld, pObj, i, Vec_PtrSize(vCosOld) - st__count(tLatches) )
        Vec_PtrPush( vCosNew, pObj );
    Vec_PtrForEachEntryStop( Abc_Obj_t *, vBoxesOld, pObj, i, Vec_PtrSize(vBoxesOld) - st__count(tLatches) )
        Vec_PtrPush( vBoxesNew, pObj );
    // go through the latches
    Abc_NtkForEachObj( pNtk, pLatch, i )
    {
        if ( !Abc_ObjIsLatch(pLatch) )
            continue;
        if ( Abc_ObjId(pLatch) >= (unsigned)nIdMaxStart )
        {
            // this is a new latch 
            pLatchIn  = Abc_NtkCreateBi(pNtk);
            pLatchOut = Abc_NtkCreateBo(pNtk);
            Abc_ObjAssignName( pLatchOut, Abc_ObjName(pLatch), "_out" );
            Abc_ObjAssignName( pLatchIn,  Abc_ObjName(pLatch), "_in" );
        }
        else
        {
            // this is an old latch 
            // get its number in the original order
            if ( ! st__lookup( tLatches, (char *)pLatch, (char **)&Index ) )
            {
                printf( "Abc_NtkRetimeFinalizeLatches(): Internal error.\n" );
                return 0;
            }
            assert( pLatch == Vec_PtrEntry(vBoxesOld, Vec_PtrSize(vBoxesOld) - st__count(tLatches) + Index) );
            // reconnect with the old LIs/LOs
            pLatchIn  = (Abc_Obj_t *)Vec_PtrEntry( vCosOld, Vec_PtrSize(vCosOld) - st__count(tLatches) + Index );
            pLatchOut = (Abc_Obj_t *)Vec_PtrEntry( vCisOld, Vec_PtrSize(vCisOld) - st__count(tLatches) + Index );
        }
        // connect
        Abc_ObjAddFanin( pLatchIn, Abc_ObjFanin0(pLatch) );
        Abc_ObjPatchFanin( pLatch, Abc_ObjFanin0(pLatch), pLatchIn );
        if ( Abc_ObjFanoutNum(pLatch) > 0 )
            Abc_ObjTransferFanout( pLatch, pLatchOut );
        Abc_ObjAddFanin( pLatchOut, pLatch );
        // add to the arrays
        Vec_PtrPush( vCisNew, pLatchOut );
        Vec_PtrPush( vCosNew, pLatchIn );
        Vec_PtrPush( vBoxesNew, pLatch );
    }
    // free useless Cis/Cos
    Vec_PtrForEachEntry( Abc_Obj_t *, vCisOld, pObj, i )
        if ( !Abc_ObjIsPi(pObj) && Abc_ObjFaninNum(pObj) == 0 && Abc_ObjFanoutNum(pObj) == 0 )
            Abc_NtkDeleteObj(pObj);
    Vec_PtrForEachEntry( Abc_Obj_t *, vCosOld, pObj, i )
        if ( !Abc_ObjIsPo(pObj) && Abc_ObjFaninNum(pObj) == 0 && Abc_ObjFanoutNum(pObj) == 0 )
            Abc_NtkDeleteObj(pObj);
    // set the new arrays
    pNtk->vCis   = vCisNew;   Vec_PtrFree( vCisOld );
    pNtk->vCos   = vCosNew;   Vec_PtrFree( vCosOld );
    pNtk->vBoxes = vBoxesNew; Vec_PtrFree( vBoxesOld );
    return 1;
}

int Abc_NtkRetimeIncremental	(	Abc_Ntk_t *	pNtk,
		int	nDelayLim,
		int	fForward,
		int	fMinDelay,
		int	fOneStep,
		int	fVerbose
	)

FUNCTION DEFINITIONS ///.

Function*************************************************************

Synopsis [Performs retiming in one direction.]

Description [Currently does not retime over black boxes.]

SideEffects []

SeeAlso []

Definition at line 47 of file retIncrem.c.

{
    Abc_Ntk_t * pNtkCopy = NULL;
    Vec_Ptr_t * vBoxes;
    st__table * tLatches;
    int nLatches = Abc_NtkLatchNum(pNtk);
    int nIdMaxStart = Abc_NtkObjNumMax(pNtk);
    int RetValue;
    int nIterLimit = -1; // Suppress "might be used uninitialized"
    if ( Abc_NtkNodeNum(pNtk) == 0 )
        return 0;
    // reorder CI/CO/latch inputs
    Abc_NtkOrderCisCos( pNtk );
    if ( fMinDelay ) 
    {
        nIterLimit = fOneStep? 1 : 2 * Abc_NtkLevel(pNtk);
        pNtkCopy = Abc_NtkDup( pNtk );
        tLatches = Abc_NtkRetimePrepareLatches( pNtkCopy );
        st__free_table( tLatches );
    }
    // collect latches and remove CIs/COs
    tLatches = Abc_NtkRetimePrepareLatches( pNtk );
    // share the latches
    Abc_NtkRetimeShareLatches( pNtk, 0 );    
    // save boxes
    vBoxes = pNtk->vBoxes;  pNtk->vBoxes = NULL;
    // perform the retiming
    if ( fMinDelay )
        Abc_NtkRetimeMinDelay( pNtk, pNtkCopy, nDelayLim, nIterLimit, fForward, fVerbose );
    else
        Abc_NtkRetimeOneWay( pNtk, fForward, fVerbose );
    if ( fMinDelay ) 
        Abc_NtkDelete( pNtkCopy );
    // share the latches
    Abc_NtkRetimeShareLatches( pNtk, 0 );    
    // restore boxes
    pNtk->vBoxes = vBoxes;
    // finalize the latches
    RetValue = Abc_NtkRetimeFinalizeLatches( pNtk, tLatches, nIdMaxStart );
    st__free_table( tLatches );
    if ( RetValue == 0 )
        return 0;
    // fix the COs
//    Abc_NtkLogicMakeSimpleCos( pNtk, 0 );
    // check for correctness
    if ( !Abc_NtkCheck( pNtk ) )
        fprintf( stdout, "Abc_NtkRetimeForward(): Network check has failed.\n" );
    // return the number of latches saved
    return nLatches - Abc_NtkLatchNum(pNtk);
}

Vec_Int_t* Abc_NtkRetimeInitialValues	(	Abc_Ntk_t *	pNtkCone,
		Vec_Int_t *	vValues,
		int	fVerbose
	)

FUNCTION DEFINITIONS ///.

Function*************************************************************

Synopsis [Computes initial values of the new latches.]

Description []

SideEffects []

SeeAlso []

Definition at line 47 of file retInit.c.

{
    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;
}

void Abc_NtkRetimeInsertLatchValues	(	Abc_Ntk_t *	pNtk,
		Vec_Int_t *	vValues
	)

Function*************************************************************

Synopsis [Transfer latch initial values from pCopy.]

Description []

SideEffects []

SeeAlso []

Definition at line 231 of file retInit.c.

{
    Abc_Obj_t * pObj;
    int i, Counter = 0;
    Abc_NtkForEachObj( pNtk, pObj, i )
        if ( Abc_ObjIsLatch(pObj) )
            pObj->pCopy = (Abc_Obj_t *)(ABC_PTRUINT_T)Counter++;
    Abc_NtkForEachObj( pNtk, pObj, i )
        if ( Abc_ObjIsLatch(pObj) )
            pObj->pData = (Abc_Obj_t *)(ABC_PTRUINT_T)(vValues? (Vec_IntEntry(vValues,(int)(ABC_PTRUINT_T)pObj->pCopy)? ABC_INIT_ONE : ABC_INIT_ZERO) : ABC_INIT_DC);
}

int Abc_NtkRetimeLValue	(	Abc_Ntk_t *	pNtk,
		int	nIterLimit,
		int	fVerbose
	)

FUNCTION DEFINITIONS ///.

Function*************************************************************

Synopsis [Implements Pan's retiming algorithm.]

Description []

SideEffects []

SeeAlso []

Definition at line 61 of file retLvalue.c.

{
    Vec_Int_t * vLags;
    int nLatches = Abc_NtkLatchNum(pNtk);
    assert( Abc_NtkIsLogic( pNtk ) );
    // get the lags
    vLags = Abc_NtkRetimeGetLags( pNtk, nIterLimit, fVerbose );
    // compute the retiming
//    Abc_NtkRetimeUsingLags( pNtk, vLags, fVerbose );
    Vec_IntFree( vLags );
    // fix the COs
//    Abc_NtkLogicMakeSimpleCos( pNtk, 0 );
    // check for correctness
    if ( !Abc_NtkCheck( pNtk ) )
        fprintf( stdout, "Abc_NtkRetimeLValue(): Network check has failed.\n" );
    // return the number of latches saved
    return nLatches - Abc_NtkLatchNum(pNtk);
}

ABC_NAMESPACE_HEADER_START int Abc_NtkRetimeMinArea	(	Abc_Ntk_t *	pNtk,
		int	fForwardOnly,
		int	fBackwardOnly,
		int	fVerbose
	)

INCLUDES ///.

CFile****************************************************************

FileName [retInt.h]

SystemName [ABC: Logic synthesis and verification system.]

PackageName [Retiming package.]

Synopsis [Internal declarations.]

Author [Alan Mishchenko]

Affiliation [UC Berkeley]

Date [Ver. 1.0. Started - Oct 31, 2006.]

Revision [

Id:

retInt.h,v 1.00 2006/10/31 00:00:00 alanmi Exp

]PARAMETERS ///STRUCTURE DEFINITIONS ///MACRO DEFINITIONS ///FUNCTION DECLARATIONS ///

INCLUDES ///.

Function*************************************************************

Synopsis [Performs min-area retiming.]

Description [Returns the number of latches reduced.]

SideEffects []

SeeAlso []

Definition at line 53 of file retArea.c.

{
    Abc_Ntk_t * pNtkTotal = NULL, * pNtkBottom;
    Vec_Int_t * vValuesNew = NULL, * vValues;
    int nLatches = Abc_NtkLatchNum(pNtk);
    int fOneFrame = 0;
    assert( !fForwardOnly || !fBackwardOnly );
    // there should not be black boxes
    assert( Abc_NtkIsSopLogic(pNtk) );
    assert( Abc_NtkLatchNum(pNtk) == Vec_PtrSize(pNtk->vBoxes) );
    // reorder CI/CO/latch inputs
    Abc_NtkOrderCisCos( pNtk );
    // perform forward retiming
    if ( !fBackwardOnly )
    {
        if ( fOneFrame )
            Abc_NtkRetimeMinAreaOne( pNtk, 1, fVerbose );
        else
            while ( Abc_NtkRetimeMinAreaOne( pNtk, 1, fVerbose ) );
    }
    // remember initial values
    vValues = Abc_NtkCollectLatchValues( pNtk );
    // perform backward retiming
    if ( !fForwardOnly )
    {
        if ( fOneFrame )
            pNtkTotal = Abc_NtkRetimeMinAreaOne( pNtk, 0, fVerbose );
        else
            while ( (pNtkBottom = Abc_NtkRetimeMinAreaOne( pNtk, 0, fVerbose )) )
                pNtkTotal = Abc_NtkAttachBottom( pNtkTotal, pNtkBottom );  
    }
    // compute initial values
    vValuesNew = Abc_NtkRetimeInitialValues( pNtkTotal, vValues, fVerbose );
    if ( pNtkTotal ) Abc_NtkDelete( pNtkTotal );
    // insert new initial values
    Abc_NtkInsertLatchValues( pNtk, vValuesNew );
    if ( vValuesNew ) Vec_IntFree( vValuesNew );
    if ( vValues )    Vec_IntFree( vValues );
    // fix the COs (this changes the circuit structure)
//    Abc_NtkLogicMakeSimpleCos( pNtk, 0 );
    // check for correctness
    if ( !Abc_NtkCheck( pNtk ) )
        fprintf( stdout, "Abc_NtkRetimeMinArea(): Network check has failed.\n" );
    // return the number of latches saved
    return nLatches - Abc_NtkLatchNum(pNtk);
}

int Abc_NtkRetimeMinDelay	(	Abc_Ntk_t *	pNtk,
		Abc_Ntk_t *	pNtkCopy,
		int	nDelayLim,
		int	nIterLimit,
		int	fForward,
		int	fVerbose
	)

FUNCTION DEFINITIONS ///.

Function*************************************************************

Synopsis [Retimes incrementally for minimum delay.]

Description [This procedure cannot be called in the application code because it assumes that the network is preprocessed by removing LIs/LOs.]

SideEffects []

SeeAlso []

Definition at line 50 of file retDelay.c.

{
    int IterBest, DelayBest;
    int IterBest2, DelayBest2;
    // try to find the best delay iteration on a copy
    DelayBest = Abc_NtkRetimeMinDelayTry( pNtkCopy, nDelayLim, fForward, 0, nIterLimit, &IterBest, fVerbose );
    if ( IterBest == 0 )
        return 1;
    // perform the given number of iterations on the original network
    DelayBest2 = Abc_NtkRetimeMinDelayTry( pNtk, nDelayLim, fForward, 1, IterBest, &IterBest2, fVerbose );
    assert( DelayBest == DelayBest2 );
    assert( IterBest == IterBest2 );
    return 1;
}

void Abc_NtkRetimeNode	(	Abc_Obj_t *	pObj,
		int	fForward,
		int	fInitial
	)

Function*************************************************************

Synopsis [Retimes the node backward or forward.]

Description []

SideEffects []

SeeAlso []

Definition at line 315 of file retIncrem.c.

{
    Abc_Ntk_t * pNtkNew = NULL;
    Vec_Ptr_t * vNodes;
    Abc_Obj_t * pNext, * pLatch;
    int i;
    vNodes = Vec_PtrAlloc( 10 );
    if ( fForward ) 
    {
        // compute the initial value
        if ( fInitial )
            pObj->pCopy = (Abc_Obj_t *)(ABC_PTRUINT_T)Abc_ObjSopSimulate( pObj );
        // collect fanins
        Abc_NodeCollectFanins( pObj, vNodes );
        // make the node point to the fanins fanins
        Vec_PtrForEachEntry( Abc_Obj_t *, vNodes, pNext, i )
        {
            assert( Abc_ObjIsLatch(pNext) );
            Abc_ObjPatchFanin( pObj, pNext, Abc_ObjFanin0(pNext) );
            if ( Abc_ObjFanoutNum(pNext) == 0 )
                Abc_NtkDeleteObj(pNext);            
        }
        // add a new latch on top
        pNext = Abc_NtkCreateLatch(pObj->pNtk);
        if ( Abc_ObjFanoutNum(pObj) > 0 )
            Abc_ObjTransferFanout( pObj, pNext );
        Abc_ObjAddFanin( pNext, pObj );
        // set the initial value
        if ( fInitial )
            pNext->pCopy = pObj->pCopy;
    }
    else
    {
        // compute the initial value
        if ( fInitial )
        {
            pNtkNew = Abc_ObjFanout0(pObj)->pCopy->pNtk;
            Abc_NtkDupObj( pNtkNew, pObj, 0 );
            Abc_ObjForEachFanout( pObj, pNext, i )
            {
                assert( Abc_ObjFaninNum(pNext->pCopy) == 0 );
                Abc_ObjAddFanin( pNext->pCopy, pObj->pCopy );
            }
        }
        // collect fanouts
        Abc_NodeCollectFanouts( pObj, vNodes );
        // make the fanouts fanouts point to the node
        Vec_PtrForEachEntry( Abc_Obj_t *, vNodes, pNext, i )
        {
            assert( Abc_ObjIsLatch(pNext) );
            Abc_ObjTransferFanout( pNext, pObj );
            Abc_NtkDeleteObj( pNext );  
        }
        // add new latches to the fanins
        Abc_ObjForEachFanin( pObj, pNext, i )
        {
            pLatch = Abc_NtkCreateLatch(pObj->pNtk);
            Abc_ObjPatchFanin( pObj, pNext, pLatch );
            Abc_ObjAddFanin( pLatch, pNext );
            // create buffer isomorphic to this latch
            if ( fInitial )
            {
                pLatch->pCopy = Abc_NtkCreateNodeBuf( pNtkNew, NULL );
                Abc_ObjAddFanin( pObj->pCopy, pLatch->pCopy );
            }
        }
    }
    Vec_PtrFree( vNodes );
}

int Abc_NtkRetimeNodeIsEnabled	(	Abc_Obj_t *	pObj,
		int	fForward
	)

Function*************************************************************

Synopsis [Returns 1 if retiming forward/backward is possible.]

Description []

SideEffects []

SeeAlso []

Definition at line 284 of file retIncrem.c.

{
    Abc_Obj_t * pNext;
    int i;
    assert( Abc_ObjIsNode(pObj) );
    if ( fForward )
    {
        Abc_ObjForEachFanin( pObj, pNext, i )
            if ( !Abc_ObjIsLatch(pNext) )
                return 0;
    }
    else
    {
        Abc_ObjForEachFanout( pObj, pNext, i )
            if ( !Abc_ObjIsLatch(pNext) )
                return 0;
    }
    return 1;
}

st__table* Abc_NtkRetimePrepareLatches

(

Abc_Ntk_t *

pNtk

)

Function*************************************************************

Synopsis [Prepares the network for retiming.]

Description [Hash latches into their number in the original network.]

SideEffects []

SeeAlso []

Definition at line 109 of file retIncrem.c.

{
    st__table * tLatches;
    Abc_Obj_t * pLatch, * pLatchIn, * pLatchOut, * pFanin;
    int i, nOffSet = Abc_NtkBoxNum(pNtk) - Abc_NtkLatchNum(pNtk);
    // collect latches and remove CIs/COs
    tLatches = st__init_table( st__ptrcmp, st__ptrhash );
    Abc_NtkForEachLatch( pNtk, pLatch, i )
    {
        // map latch into its true number
        st__insert( tLatches, (char *)(ABC_PTRUINT_T)pLatch, (char *)(ABC_PTRUINT_T)(i-nOffSet) );
        // disconnect LI     
        pLatchIn = Abc_ObjFanin0(pLatch);
        pFanin = Abc_ObjFanin0(pLatchIn);
        Abc_ObjTransferFanout( pLatchIn, pFanin );
        Abc_ObjDeleteFanin( pLatchIn, pFanin );
        // disconnect LO     
        pLatchOut = Abc_ObjFanout0(pLatch);
        pFanin = Abc_ObjFanin0(pLatchOut);
        if ( Abc_ObjFanoutNum(pLatchOut) > 0 )
            Abc_ObjTransferFanout( pLatchOut, pFanin );
        Abc_ObjDeleteFanin( pLatchOut, pFanin );
    }
    return tLatches;
}

void Abc_NtkRetimeShareLatches	(	Abc_Ntk_t *	pNtk,
		int	fInitial
	)

Function*************************************************************

Synopsis [Retimes the node backward or forward.]

Description []

SideEffects []

SeeAlso []

Definition at line 426 of file retIncrem.c.

{
    Vec_Ptr_t * vNodes;
    Abc_Obj_t * pFanin, * pLatchTop, * pLatchCur;
    int i, k;
    vNodes = Vec_PtrAlloc( 10 );
    // consider latch fanins
    Abc_NtkForEachObj( pNtk, pFanin, i )
    {
        if ( Abc_NtkRetimeCheckCompatibleLatchFanouts(pFanin) <= 1 )
            continue;
        // get the first latch
        pLatchTop = NULL;
        Abc_ObjForEachFanout( pFanin, pLatchTop, k )
            if ( Abc_ObjIsLatch(pLatchTop) )
                break;
        assert( pLatchTop && Abc_ObjIsLatch(pLatchTop) );
        // redirect compatible fanout latches to the first latch
        Abc_NodeCollectFanouts( pFanin, vNodes );
        Vec_PtrForEachEntry( Abc_Obj_t *, vNodes, pLatchCur, k )
        {
            if ( !Abc_ObjIsLatch(pLatchCur) )
                continue;
            if ( pLatchCur == pLatchTop )
                continue;
            if ( pLatchCur->pData != pLatchTop->pData )
                continue;
            // connect the initial state
            if ( fInitial )
                Abc_ObjAddFanin( pLatchCur->pCopy, pLatchTop->pCopy );
            // redirect the fanouts
            Abc_ObjTransferFanout( pLatchCur, pLatchTop );
            Abc_NtkDeleteObj(pLatchCur);
        }
    }
    Vec_PtrFree( vNodes );
}

void Abc_NtkRetimeTranferFromCopy

(

Abc_Ntk_t *

pNtk

)

Function*************************************************************

Synopsis [Transfer latch initial values from pCopy.]

Description []

SideEffects []

SeeAlso []

Definition at line 188 of file retInit.c.

{
    Abc_Obj_t * pObj;
    int i;
    Abc_NtkForEachObj( pNtk, pObj, i )
        if ( Abc_ObjIsLatch(pObj) )
            pObj->pData = (void *)(ABC_PTRUINT_T)(pObj->pCopy? ABC_INIT_ONE : ABC_INIT_ZERO);
}

void Abc_NtkRetimeTranferToCopy

(

Abc_Ntk_t *

pNtk

)

Function*************************************************************

Synopsis [Transfer latch initial values to pCopy.]

Description []

SideEffects []

SeeAlso []

Definition at line 168 of file retInit.c.

{
    Abc_Obj_t * pObj;
    int i;
    Abc_NtkForEachObj( pNtk, pObj, i )
        if ( Abc_ObjIsLatch(pObj) )
            pObj->pCopy = (Abc_Obj_t *)(ABC_PTRUINT_T)Abc_LatchIsInit1(pObj);
}

int Abc_ObjSopSimulate

(

Abc_Obj_t *

pObj

)

Function*************************************************************

Synopsis [Computes the results of simulating one node.]

Description [Assumes that fanins have pCopy set to the input values.]

SideEffects []

SeeAlso []

Definition at line 93 of file retInit.c.

{
    char * pCube, * pSop = (char *)pObj->pData;
    int nVars, Value, v, ResOr, ResAnd, ResVar;
    assert( pSop && !Abc_SopIsExorType(pSop) );
    // simulate the SOP of the node
    ResOr = 0;
    nVars = Abc_SopGetVarNum(pSop);
    Abc_SopForEachCube( pSop, nVars, pCube )
    {
        ResAnd = 1;
        Abc_CubeForEachVar( pCube, Value, v )
        {
            if ( Value == '0' )
                ResVar = 1 ^ ((int)(ABC_PTRUINT_T)Abc_ObjFanin(pObj, v)->pCopy);
            else if ( Value == '1' )
                ResVar = (int)(ABC_PTRUINT_T)Abc_ObjFanin(pObj, v)->pCopy;
            else
                continue;
            ResAnd &= ResVar;
        }
        ResOr |= ResAnd;
    }
    // complement the result if necessary
    if ( !Abc_SopGetPhase(pSop) )
        ResOr ^= 1;
    return ResOr;
}