src/map/super/superGate.c

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#include "superInt.h"


// the bit masks
#define SUPER_MASK(n)     ((~((unsigned)0)) >> (32-(n)))
#define SUPER_FULL         (~((unsigned)0))
#define SUPER_NO_VAR         (-9999.0)
#define SUPER_EPSILON        (0.001)

// data structure for supergate precomputation
typedef struct Super_ManStruct_t_     Super_Man_t;   // manager
typedef struct Super_GateStruct_t_    Super_Gate_t;  // supergate

struct Super_ManStruct_t_
{
    // parameters
    char *              pName;        // the original genlib file name
    int                 nVarsMax;     // the number of inputs
    int                 nMints;       // the number of minterms
    int                 nLevels;      // the number of logic levels
    float               tDelayMax;    // the max delay of the supergates in the library
    float               tAreaMax;     // the max area of the supergates in the library
    int                 fSkipInv;     // the flag says about skipping inverters
    int                 fWriteOldFormat; // in addition, writes the file in the old format
    int                 fVerbose;

    // supergates
    Super_Gate_t *      pInputs[10];  // the input supergates
    int                 nGates;       // the number of gates in the library
    Super_Gate_t **     pGates;       // the gates themselves
    stmm_table *        tTable;       // mapping of truth tables into gates

    // memory managers
    Extra_MmFixed_t *   pMem;         // memory manager for the supergates
    Extra_MmFlex_t *    pMemFlex;     // memory manager for the fanin arrays

    // statistics
    int                 nTried;       // the total number of tried
    int                 nAdded;       // the number of entries added
    int                 nRemoved;     // the number of entries removed
    int                 nUnique;      // the number of unique gates
    int                 nLookups;     // the number of hash table lookups
    int                 nAliases;     // the number of hash table lookups thrown away due to aliasing

    // runtime
    int                 Time;         // the runtime of the generation procedure
    int                 TimeLimit;    // the runtime limit (in seconds)
    int                 TimeSec;      // the time passed (in seconds)
    int                 TimeStop;     // the time to stop computation (in miliseconds)
    int                 TimePrint;    // the time to print message
};

struct Super_GateStruct_t_
{
    Mio_Gate_t *        pRoot;        // the root gate for this supergate
    unsigned            fVar :     1; // the flag signaling the elementary variable
    unsigned            fSuper :   1; // the flag signaling the elementary variable
    unsigned            nFanins :  6; // the number of fanin gates
    unsigned            Number :  24; // the number assigned in the process
    unsigned            uTruth[2];    // the truth table of this supergate
    Super_Gate_t *      pFanins[6];   // the fanins of the gate
    float               Area;         // the area of this gate
    float               ptDelays[6];  // the pin-to-pin delays for all inputs
    float               tDelayMax;    // the maximum delay
    Super_Gate_t *      pNext;        // the next gate in the table
};


// iterating through the gates in the library
#define Super_ManForEachGate( GateArray, Limit, Index, Gate )    \
    for ( Index = 0;                                             \
          Index < Limit && (Gate = GateArray[Index]);            \
          Index++ )

// static functions
static Super_Man_t *  Super_ManStart();
static void           Super_ManStop( Super_Man_t * pMan );

static void           Super_AddGateToTable( Super_Man_t * pMan, Super_Gate_t * pGate );
static void           Super_First( Super_Man_t * pMan, int nVarsMax );
static Super_Man_t *  Super_Compute( Super_Man_t * pMan, Mio_Gate_t ** ppGates, int nGates, bool fSkipInv );
static Super_Gate_t * Super_CreateGateNew( Super_Man_t * pMan, Mio_Gate_t * pRoot, Super_Gate_t ** pSupers, int nSupers, unsigned uTruth[], float Area, float tPinDelaysRes[], float tDelayMax, int nPins );
static bool           Super_CompareGates( Super_Man_t * pMan, unsigned uTruth[], float Area, float tPinDelaysRes[], int nPins );
static int            Super_DelayCompare( Super_Gate_t ** ppG1, Super_Gate_t ** ppG2 );
static int            Super_AreaCompare( Super_Gate_t ** ppG1, Super_Gate_t ** ppG2 );
static void           Super_TranferGatesToArray( Super_Man_t * pMan );
static int            Super_CheckTimeout( ProgressBar * pPro, Super_Man_t * pMan );
 
static void           Super_Write( Super_Man_t * pMan );
static int            Super_WriteCompare( Super_Gate_t ** ppG1, Super_Gate_t ** ppG2 );
static void           Super_WriteFileHeader( Super_Man_t * pMan, FILE * pFile );

static void           Super_WriteLibrary( Super_Man_t * pMan );
static void           Super_WriteLibraryGate( FILE * pFile, Super_Man_t * pMan, Super_Gate_t * pGate, int Num );
static char *         Super_WriteLibraryGateName( Super_Gate_t * pGate );
static void           Super_WriteLibraryGateName_rec( Super_Gate_t * pGate, char * pBuffer );

static void           Super_WriteLibraryTree( Super_Man_t * pMan );
static void           Super_WriteLibraryTree_rec( FILE * pFile, Super_Man_t * pMan, Super_Gate_t * pSuper, int * pCounter );


void Super_Precompute( Mio_Library_t * pLibGen, int nVarsMax, int nLevels, float tDelayMax, float tAreaMax, int TimeLimit, bool fSkipInv, bool fWriteOldFormat, int fVerbose )
{
    Super_Man_t * pMan;
    Mio_Gate_t ** ppGates;
    int nGates, Level, clk, clockStart;

    assert( nVarsMax < 7 );

    // get the root gates
    ppGates = Mio_CollectRoots( pLibGen, nVarsMax, tDelayMax, 0, &nGates );

    // start the manager
    pMan = Super_ManStart();
    pMan->pName     = Mio_LibraryReadName(pLibGen);
    pMan->fSkipInv  = fSkipInv;
    pMan->tDelayMax = tDelayMax;
    pMan->tAreaMax  = tAreaMax;
    pMan->TimeLimit = TimeLimit; // in seconds
    pMan->TimeStop  = TimeLimit * CLOCKS_PER_SEC + clock(); // in CPU ticks
    pMan->fWriteOldFormat = fWriteOldFormat;
    pMan->fVerbose = fVerbose;

    if ( nGates == 0 )
    {
        fprintf( stderr, "Error: No genlib gates satisfy the limits criteria. Stop.\n");
        fprintf( stderr, "Limits: max delay =  %.2f, max area =  %.2f, time limit = %d sec.\n", 
            pMan->tDelayMax, pMan->tAreaMax, pMan->TimeLimit );

        // stop the manager
        Super_ManStop( pMan );
        free( ppGates );

        return;
    }

    // get the starting supergates
    Super_First( pMan, nVarsMax );

    // perform the computation of supergates
    clockStart = clock();
if ( fVerbose )
{
    printf( "Computing supergates with %d inputs and %d levels.\n", 
        pMan->nVarsMax, nLevels );
    printf( "Limits: max delay =  %.2f, max area =  %.2f, time limit = %d sec.\n", 
        pMan->tDelayMax, pMan->tAreaMax, pMan->TimeLimit );
}

    for ( Level = 1; Level <= nLevels; Level++ )
    {
        if ( clock() > pMan->TimeStop )
            break;
clk = clock();
        Super_Compute( pMan, ppGates, nGates, fSkipInv );
        pMan->nLevels = Level;
if ( fVerbose )
{
        printf( "Lev %d: Try =%12d. Add =%6d. Rem =%5d. Save =%6d. Lookups =%12d. Aliases =%12d. ",
           Level, pMan->nTried, pMan->nAdded, pMan->nRemoved, pMan->nAdded - pMan->nRemoved, pMan->nLookups, pMan->nAliases );
PRT( "Time", clock() - clk );
fflush( stdout );
}
    }
    pMan->Time = clock() - clockStart;

if ( fVerbose )
{
printf( "Writing the output file...\n" );
fflush( stdout );
}
    // write them into a file
    Super_Write( pMan );

    // stop the manager
    Super_ManStop( pMan );
    free( ppGates );
}


void Super_First( Super_Man_t * pMan, int nVarsMax )
{
    Super_Gate_t * pSuper;
    int nMintLimit, nVarLimit;
    int v, m;
    // set the parameters
    pMan->nVarsMax  = nVarsMax;
    pMan->nMints    = (1 << nVarsMax);
    pMan->nLevels   = 0;
    // allocate room for the gates
    pMan->nGates    = nVarsMax;  
    pMan->pGates    = ALLOC( Super_Gate_t *, nVarsMax + 2 ); 
    // create the gates corresponding to the elementary variables
    for ( v = 0; v < nVarsMax; v++ )
    {
        // get a new gate
        pSuper = (Super_Gate_t *)Extra_MmFixedEntryFetch( pMan->pMem );
        memset( pSuper, 0, sizeof(Super_Gate_t) );
        // assign the elementary variable, the truth table, and the delays
        pSuper->fVar = 1;
        pSuper->Number = v;
        for ( m = 0; m < nVarsMax; m++ )
            pSuper->ptDelays[m] = SUPER_NO_VAR;
        pSuper->ptDelays[v] = 0.0;
        // set the gate
        pMan->pGates[v] = pSuper;
        Super_AddGateToTable( pMan, pSuper );
        pMan->pInputs[v] = pSuper;
    }
    // set up their truth tables
    nVarLimit  = (nVarsMax >= 5)? 5 : nVarsMax;
    nMintLimit = (1 << nVarLimit);
    for ( m = 0; m < nMintLimit; m++ )
        for ( v = 0; v < nVarLimit; v++ )
            if ( m & (1 << v) )
                pMan->pGates[v]->uTruth[0] |= (1 << m);
    // make adjustments for the case of 6 variables
    if ( nVarsMax == 6 )
    {
        for ( v = 0; v < 5; v++ )
            pMan->pGates[v]->uTruth[1] = pMan->pGates[v]->uTruth[0];
        pMan->pGates[5]->uTruth[0] = 0;
        pMan->pGates[5]->uTruth[1] = ~((unsigned)0);
    }
    else
    {
        for ( v = 0; v < nVarsMax; v++ )
            pMan->pGates[v]->uTruth[1] = 0;
    }
}

Super_Man_t * Super_Compute( Super_Man_t * pMan, Mio_Gate_t ** ppGates, int nGates, bool fSkipInv )
{
    Super_Gate_t * pSupers[6], * pGate0, * pGate1, * pGate2, * pGate3, * pGate4, * pGate5, * pGateNew;
    float tPinDelaysRes[6], * ptPinDelays[6], tPinDelayMax, tDelayMio;
    float Area, Area0, Area1, Area2, Area3, Area4, AreaMio;
    unsigned uTruth[2], uTruths[6][2];
    int i0, i1, i2, i3, i4, i5; 
    Super_Gate_t ** ppGatesLimit;
    int nFanins, nGatesLimit, k, s, t;
    ProgressBar * pProgress;
    int fTimeOut;
    int fPrune = 1;                     // Shall we prune?
    int iPruneLimit = 3;                // Each of the gates plugged into the root gate will have 
                                        // less than these many fanins
    int iPruneLimitRoot = 4;            // The root gate may have only less than these many fanins

    // put the gates from the unique table into the array
    // the gates from the array will be used to compose other gates
    // the gates in tbe table are used to check uniqueness of collected gates
    Super_TranferGatesToArray( pMan );

    // sort the gates in the increasing order of maximum delay
    if ( pMan->nGates > 10000 )
    {
        printf( "Sorting array of %d supergates...\r", pMan->nGates );
        fflush( stdout );
    }
    qsort( (void *)pMan->pGates, pMan->nGates, sizeof(Super_Gate_t *), 
            (int (*)(const void *, const void *)) Super_DelayCompare );
    assert( Super_DelayCompare( pMan->pGates, pMan->pGates + pMan->nGates - 1 ) <= 0 );
    if ( pMan->nGates > 10000 )
    {
        printf( "                                       \r" );
    }

    pProgress = Extra_ProgressBarStart( stdout, pMan->TimeLimit );
    pMan->TimePrint = clock() + CLOCKS_PER_SEC;
    ppGatesLimit = ALLOC( Super_Gate_t *, pMan->nGates );
    // go through the root gates
    // the root gates are sorted in the increasing gelay
    fTimeOut = 0;
    for ( k = 0; k < nGates; k++ )
    {
        if ( fTimeOut ) break;

        if ( fPrune )
        {
            if ( pMan->nLevels >= 1 )  // First level gates have been computed
            {
                if ( Mio_GateReadInputs(ppGates[k]) >= iPruneLimitRoot )
                    continue;
            }
        }

        // select the subset of gates to be considered with this root gate
        // all the gates past this point will lead to delay larger than the limit
        tDelayMio = (float)Mio_GateReadDelayMax(ppGates[k]);
        for ( s = 0, t = 0; s < pMan->nGates; s++ )
        {
            if ( fPrune && ( pMan->nLevels >= 1 ) && ( ((int)pMan->pGates[s]->nFanins) >= iPruneLimit ))
                continue;
            
            ppGatesLimit[t] = pMan->pGates[s];
            if ( ppGatesLimit[t++]->tDelayMax + tDelayMio > pMan->tDelayMax )
                break;
        }
        nGatesLimit = t;

        if ( pMan->fVerbose )
        {
            printf ("Trying %d choices for %d inputs\n", t, Mio_GateReadInputs(ppGates[k]) );
        }

        // resort part of this range by area
        // now we can prune the search by going up in the list until we reach the limit on area
        // all the gates beyond this point can be skipped because their area can be only larger
        if ( nGatesLimit > 10000 )
            printf( "Sorting array of %d supergates...\r", nGatesLimit );
        qsort( (void *)ppGatesLimit, nGatesLimit, sizeof(Super_Gate_t *), 
                (int (*)(const void *, const void *)) Super_AreaCompare );
        assert( Super_AreaCompare( ppGatesLimit, ppGatesLimit + nGatesLimit - 1 ) <= 0 );
        if ( nGatesLimit > 10000 )
            printf( "                                       \r" );

        // consider the combinations of gates with the root gate on top
        AreaMio = (float)Mio_GateReadArea(ppGates[k]);
        nFanins = Mio_GateReadInputs(ppGates[k]);
        switch ( nFanins )
        {
        case 0: // should not happen
            assert( 0 ); 
            break;
        case 1: // interter root
            Super_ManForEachGate( ppGatesLimit, nGatesLimit, i0, pGate0 )
            {
              if ( fTimeOut ) break;
              fTimeOut = Super_CheckTimeout( pProgress, pMan );
              // skip the inverter as the root gate before the elementary variable
              // as a result, the supergates will not have inverters on the input side
              // but inverters still may occur at the output of or inside complex supergates
              if ( fSkipInv && pGate0->tDelayMax == 0 )
                  continue;
              // compute area
              Area = AreaMio + pGate0->Area;
              if ( Area > pMan->tAreaMax )
                  break;

              pSupers[0] = pGate0;  uTruths[0][0] = pGate0->uTruth[0];  uTruths[0][1] = pGate0->uTruth[1];  ptPinDelays[0] = pGate0->ptDelays; 
              Mio_DeriveGateDelays( ppGates[k], ptPinDelays, nFanins, pMan->nVarsMax, SUPER_NO_VAR, tPinDelaysRes, &tPinDelayMax );
              Mio_DeriveTruthTable( ppGates[k], uTruths, nFanins, pMan->nVarsMax, uTruth );
              if ( !Super_CompareGates( pMan, uTruth, Area, tPinDelaysRes, pMan->nVarsMax ) )
                  continue;
              // create a new gate
              pGateNew = Super_CreateGateNew( pMan, ppGates[k], pSupers, nFanins, uTruth, Area, tPinDelaysRes, tPinDelayMax, pMan->nVarsMax );
              Super_AddGateToTable( pMan, pGateNew );
           }
            break;
        case 2: // two-input root gate
            Super_ManForEachGate( ppGatesLimit, nGatesLimit, i0, pGate0 )
            {
              Area0 = AreaMio + pGate0->Area;
              if ( Area0 > pMan->tAreaMax )
                  break;
              pSupers[0] = pGate0;  uTruths[0][0] = pGate0->uTruth[0];  uTruths[0][1] = pGate0->uTruth[1];  ptPinDelays[0] = pGate0->ptDelays; 
              Super_ManForEachGate( ppGatesLimit, nGatesLimit, i1, pGate1 )
              if ( i1 != i0 )
              {
                if ( fTimeOut ) goto done;
                fTimeOut = Super_CheckTimeout( pProgress, pMan );
                // compute area
                Area = Area0 + pGate1->Area;
                if ( Area > pMan->tAreaMax )
                    break;

                pSupers[1] = pGate1;  uTruths[1][0] = pGate1->uTruth[0];  uTruths[1][1] = pGate1->uTruth[1];  ptPinDelays[1] = pGate1->ptDelays;
                Mio_DeriveGateDelays( ppGates[k], ptPinDelays, nFanins, pMan->nVarsMax, SUPER_NO_VAR, tPinDelaysRes, &tPinDelayMax );
                Mio_DeriveTruthTable( ppGates[k], uTruths, nFanins, pMan->nVarsMax, uTruth );
                if ( !Super_CompareGates( pMan, uTruth, Area, tPinDelaysRes, pMan->nVarsMax ) )
                    continue;
                // create a new gate
                pGateNew = Super_CreateGateNew( pMan, ppGates[k], pSupers, nFanins, uTruth, Area, tPinDelaysRes, tPinDelayMax, pMan->nVarsMax );
                Super_AddGateToTable( pMan, pGateNew );
              }
            }
            break;
        case 3: // three-input root gate
            Super_ManForEachGate( ppGatesLimit, nGatesLimit, i0, pGate0 )
            {
              Area0 = AreaMio + pGate0->Area;
              if ( Area0 > pMan->tAreaMax )
                  break;
              pSupers[0] = pGate0;  uTruths[0][0] = pGate0->uTruth[0];  uTruths[0][1] = pGate0->uTruth[1];  ptPinDelays[0] = pGate0->ptDelays; 

              Super_ManForEachGate( ppGatesLimit, nGatesLimit, i1, pGate1 )
              if ( i1 != i0 )
              {
                Area1 = Area0 + pGate1->Area;
                if ( Area1 > pMan->tAreaMax )
                    break;
                pSupers[1] = pGate1;  uTruths[1][0] = pGate1->uTruth[0];  uTruths[1][1] = pGate1->uTruth[1];  ptPinDelays[1] = pGate1->ptDelays;

                Super_ManForEachGate( ppGatesLimit, nGatesLimit, i2, pGate2 )
                if ( i2 != i0 && i2 != i1 )
                {
                  if ( fTimeOut ) goto done;
                  fTimeOut = Super_CheckTimeout( pProgress, pMan );
                  // compute area
                  Area = Area1 + pGate2->Area;
                  if ( Area > pMan->tAreaMax )
                      break;
                  pSupers[2] = pGate2;  uTruths[2][0] = pGate2->uTruth[0];  uTruths[2][1] = pGate2->uTruth[1];   ptPinDelays[2] = pGate2->ptDelays;

                  Mio_DeriveGateDelays( ppGates[k], ptPinDelays, nFanins, pMan->nVarsMax, SUPER_NO_VAR, tPinDelaysRes, &tPinDelayMax );
                  Mio_DeriveTruthTable( ppGates[k], uTruths, nFanins, pMan->nVarsMax, uTruth );
                  if ( !Super_CompareGates( pMan, uTruth, Area, tPinDelaysRes, pMan->nVarsMax ) )
                      continue;
                  // create a new gate
                  pGateNew = Super_CreateGateNew( pMan, ppGates[k], pSupers, nFanins, uTruth, Area, tPinDelaysRes, tPinDelayMax, pMan->nVarsMax );
                  Super_AddGateToTable( pMan, pGateNew );
                }
              }
            }
            break;
        case 4: // four-input root gate
            Super_ManForEachGate( ppGatesLimit, nGatesLimit, i0, pGate0 )
            {
              Area0 = AreaMio + pGate0->Area;
              if ( Area0 > pMan->tAreaMax )
                  break;
              pSupers[0] = pGate0;  uTruths[0][0] = pGate0->uTruth[0];  uTruths[0][1] = pGate0->uTruth[1];  ptPinDelays[0] = pGate0->ptDelays; 

              Super_ManForEachGate( ppGatesLimit, nGatesLimit, i1, pGate1 )
              if ( i1 != i0 )
              {
                Area1 = Area0 + pGate1->Area;
                if ( Area1 > pMan->tAreaMax )
                    break;
                pSupers[1] = pGate1;  uTruths[1][0] = pGate1->uTruth[0];  uTruths[1][1] = pGate1->uTruth[1];  ptPinDelays[1] = pGate1->ptDelays;

                Super_ManForEachGate( ppGatesLimit, nGatesLimit, i2, pGate2 )
                if ( i2 != i0 && i2 != i1 )
                {
                  Area2 = Area1 + pGate2->Area;
                  if ( Area2 > pMan->tAreaMax )
                      break;
                  pSupers[2] = pGate2;  uTruths[2][0] = pGate2->uTruth[0];  uTruths[2][1] = pGate2->uTruth[1];   ptPinDelays[2] = pGate2->ptDelays;

                  Super_ManForEachGate( ppGatesLimit, nGatesLimit, i3, pGate3 )
                  if ( i3 != i0 && i3 != i1 && i3 != i2 )
                  {
                    if ( fTimeOut ) goto done;
                    fTimeOut = Super_CheckTimeout( pProgress, pMan );
                    // compute area
                    Area = Area2 + pGate3->Area;
                    if ( Area > pMan->tAreaMax )
                        break;
                    pSupers[3] = pGate3;   uTruths[3][0] = pGate3->uTruth[0];  uTruths[3][1] = pGate3->uTruth[1];   ptPinDelays[3] = pGate3->ptDelays;

                    Mio_DeriveGateDelays( ppGates[k], ptPinDelays, nFanins, pMan->nVarsMax, SUPER_NO_VAR, tPinDelaysRes, &tPinDelayMax );
                    Mio_DeriveTruthTable( ppGates[k], uTruths, nFanins, pMan->nVarsMax, uTruth );
                    if ( !Super_CompareGates( pMan, uTruth, Area, tPinDelaysRes, pMan->nVarsMax ) )
                        continue;
                    // create a new gate
                    pGateNew = Super_CreateGateNew( pMan, ppGates[k], pSupers, nFanins, uTruth, Area, tPinDelaysRes, tPinDelayMax, pMan->nVarsMax );
                    Super_AddGateToTable( pMan, pGateNew );
                  }
                }
              }
            }
            break;
        case 5: // five-input root gate
            Super_ManForEachGate( ppGatesLimit, nGatesLimit, i0, pGate0 )
            {
              Area0 = AreaMio + pGate0->Area;
              if ( Area0 > pMan->tAreaMax )
                  break;
              pSupers[0] = pGate0;  uTruths[0][0] = pGate0->uTruth[0];  uTruths[0][1] = pGate0->uTruth[1];  ptPinDelays[0] = pGate0->ptDelays; 

              Super_ManForEachGate( ppGatesLimit, nGatesLimit, i1, pGate1 )
              if ( i1 != i0 )
              {
                Area1 = Area0 + pGate1->Area;
                if ( Area1 > pMan->tAreaMax )
                    break;
                pSupers[1] = pGate1;  uTruths[1][0] = pGate1->uTruth[0];  uTruths[1][1] = pGate1->uTruth[1];  ptPinDelays[1] = pGate1->ptDelays;

                Super_ManForEachGate( ppGatesLimit, nGatesLimit, i2, pGate2 )
                if ( i2 != i0 && i2 != i1 )
                {
                  Area2 = Area1 + pGate2->Area;
                  if ( Area2 > pMan->tAreaMax )
                      break;
                  pSupers[2] = pGate2;  uTruths[2][0] = pGate2->uTruth[0];  uTruths[2][1] = pGate2->uTruth[1];   ptPinDelays[2] = pGate2->ptDelays;

                  Super_ManForEachGate( ppGatesLimit, nGatesLimit, i3, pGate3 )
                  if ( i3 != i0 && i3 != i1 && i3 != i2 )
                  {
                    Area3 = Area2 + pGate3->Area;
                    if ( Area3 > pMan->tAreaMax )
                        break;
                    pSupers[3] = pGate3;   uTruths[3][0] = pGate3->uTruth[0];  uTruths[3][1] = pGate3->uTruth[1];   ptPinDelays[3] = pGate3->ptDelays;

                    Super_ManForEachGate( ppGatesLimit, nGatesLimit, i4, pGate4 )
                    if ( i4 != i0 && i4 != i1 && i4 != i2 && i4 != i3 )
                    {
                      if ( fTimeOut ) goto done;
                      fTimeOut = Super_CheckTimeout( pProgress, pMan );
                      // compute area
                      Area = Area3 + pGate4->Area;
                      if ( Area > pMan->tAreaMax )
                          break;
                      pSupers[4] = pGate4;   uTruths[4][0] = pGate4->uTruth[0];  uTruths[4][1] = pGate4->uTruth[1];  ptPinDelays[4] = pGate4->ptDelays;

                      Mio_DeriveGateDelays( ppGates[k], ptPinDelays, nFanins, pMan->nVarsMax, SUPER_NO_VAR, tPinDelaysRes, &tPinDelayMax );
                      Mio_DeriveTruthTable( ppGates[k], uTruths, nFanins, pMan->nVarsMax, uTruth );
                      if ( !Super_CompareGates( pMan, uTruth, Area, tPinDelaysRes, pMan->nVarsMax ) )
                          continue;
                      // create a new gate
                      pGateNew = Super_CreateGateNew( pMan, ppGates[k], pSupers, nFanins, uTruth, Area, tPinDelaysRes, tPinDelayMax, pMan->nVarsMax );
                      Super_AddGateToTable( pMan, pGateNew );
                    }
                  }
                }
              }
            }
            break;
        case 6: // six-input root gate
            Super_ManForEachGate( ppGatesLimit, nGatesLimit, i0, pGate0 )
            {
              Area0 = AreaMio + pGate0->Area;
              if ( Area0 > pMan->tAreaMax )
                  break;
              pSupers[0] = pGate0;  uTruths[0][0] = pGate0->uTruth[0];  uTruths[0][1] = pGate0->uTruth[1];  ptPinDelays[0] = pGate0->ptDelays; 

              Super_ManForEachGate( ppGatesLimit, nGatesLimit, i1, pGate1 )
              if ( i1 != i0 )
              {
                Area1 = Area0 + pGate1->Area;
                if ( Area1 > pMan->tAreaMax )
                    break;
                pSupers[1] = pGate1;  uTruths[1][0] = pGate1->uTruth[0];  uTruths[1][1] = pGate1->uTruth[1];  ptPinDelays[1] = pGate1->ptDelays;

                Super_ManForEachGate( ppGatesLimit, nGatesLimit, i2, pGate2 )
                if ( i2 != i0 && i2 != i1 )
                {
                  Area2 = Area1 + pGate2->Area;
                  if ( Area2 > pMan->tAreaMax )
                      break;
                  pSupers[2] = pGate2;  uTruths[2][0] = pGate2->uTruth[0];  uTruths[2][1] = pGate2->uTruth[1];   ptPinDelays[2] = pGate2->ptDelays;

                  Super_ManForEachGate( ppGatesLimit, nGatesLimit, i3, pGate3 )
                  if ( i3 != i0 && i3 != i1 && i3 != i2 )
                  {
                    Area3 = Area2 + pGate3->Area;
                    if ( Area3 > pMan->tAreaMax )
                        break;
                    pSupers[3] = pGate3;   uTruths[3][0] = pGate3->uTruth[0];  uTruths[3][1] = pGate3->uTruth[1];   ptPinDelays[3] = pGate3->ptDelays;

                    Super_ManForEachGate( ppGatesLimit, nGatesLimit, i4, pGate4 )
                    if ( i4 != i0 && i4 != i1 && i4 != i2 && i4 != i3 )
                    {
                      if ( fTimeOut ) break;
                      fTimeOut = Super_CheckTimeout( pProgress, pMan );
                      // compute area
                      Area4 = Area3 + pGate4->Area;
                      if ( Area > pMan->tAreaMax )
                          break;
                      pSupers[4] = pGate4;   uTruths[4][0] = pGate4->uTruth[0];  uTruths[4][1] = pGate4->uTruth[1];  ptPinDelays[4] = pGate4->ptDelays;

                      Super_ManForEachGate( ppGatesLimit, nGatesLimit, i5, pGate5 )
                      if ( i5 != i0 && i5 != i1 && i5 != i2 && i5 != i3 && i5 != i4 )
                      {
                        if ( fTimeOut ) goto done;
                        fTimeOut = Super_CheckTimeout( pProgress, pMan );
                        // compute area
                        Area = Area4 + pGate5->Area;
                        if ( Area > pMan->tAreaMax )
                            break;
                        pSupers[5] = pGate5;   uTruths[5][0] = pGate5->uTruth[0];  uTruths[5][1] = pGate5->uTruth[1];  ptPinDelays[5] = pGate5->ptDelays;

                        Mio_DeriveGateDelays( ppGates[k], ptPinDelays, nFanins, pMan->nVarsMax, SUPER_NO_VAR, tPinDelaysRes, &tPinDelayMax );
                        Mio_DeriveTruthTable( ppGates[k], uTruths, nFanins, pMan->nVarsMax, uTruth );
                        if ( !Super_CompareGates( pMan, uTruth, Area, tPinDelaysRes, pMan->nVarsMax ) )
                            continue;
                        // create a new gate
                        pGateNew = Super_CreateGateNew( pMan, ppGates[k], pSupers, nFanins, uTruth, Area, tPinDelaysRes, tPinDelayMax, pMan->nVarsMax );
                        Super_AddGateToTable( pMan, pGateNew );
                      }
                    }
                  }
                }
              }
            }
            break;
        default :
            assert( 0 );
            break;
        }
    }
done: 
    Extra_ProgressBarStop( pProgress );
    free( ppGatesLimit );
    return pMan;
}

int Super_CheckTimeout( ProgressBar * pPro, Super_Man_t * pMan )
{
    int TimeNow = clock();
    if ( TimeNow > pMan->TimePrint )
    {
        Extra_ProgressBarUpdate( pPro, ++pMan->TimeSec, NULL );
        pMan->TimePrint = clock() + CLOCKS_PER_SEC;
    }
    if ( TimeNow > pMan->TimeStop )
    {
        printf ("Timeout!\n");
        return 1;
    }
    pMan->nTried++;
    return 0;
}


void Super_TranferGatesToArray( Super_Man_t * pMan )
{
    stmm_generator * gen;
    Super_Gate_t * pGate, * pList;
    unsigned Key;

    // put the gates fron the table into the array
    free( pMan->pGates );
    pMan->pGates = ALLOC( Super_Gate_t *, pMan->nAdded );
    pMan->nGates = 0;
    stmm_foreach_item( pMan->tTable, gen, (char **)&Key, (char **)&pList )
    {
        for ( pGate = pList; pGate; pGate = pGate->pNext )
            pMan->pGates[ pMan->nGates++ ] = pGate;
    }
//    assert( pMan->nGates == pMan->nAdded - pMan->nRemoved );
}

void Super_AddGateToTable( Super_Man_t * pMan, Super_Gate_t * pGate )
{
    Super_Gate_t ** ppList;
    unsigned Key;
//    Key = pGate->uTruth[0] + 2003 * pGate->uTruth[1];
    Key = pGate->uTruth[0] ^ pGate->uTruth[1];
    if ( !stmm_find_or_add( pMan->tTable, (char *)Key, (char ***)&ppList ) )
        *ppList = NULL;
    pGate->pNext = *ppList;
    *ppList = pGate;
    pMan->nAdded++;
}

bool Super_CompareGates( Super_Man_t * pMan, unsigned uTruth[], float Area, float tPinDelaysRes[], int nPins )
{
    Super_Gate_t ** ppList, * pPrev, * pGate, * pGate2;
    int i, fNewIsBetter, fGateIsBetter;
    unsigned Key;

    // skip constant functions
    if ( pMan->nVarsMax < 6 )
    {
        if ( uTruth[0] == 0 || ~uTruth[0] == 0 )
            return 0;
    }
    else
    {
        if ( ( uTruth[0] == 0 && uTruth[1] == 0 ) || ( ~uTruth[0] == 0 && ~uTruth[1] == 0 ) )
            return 0;
    }

    // get hold of the place where the entry is stored
//    Key = uTruth[0] + 2003 * uTruth[1];
    Key = uTruth[0] ^ uTruth[1];
    if ( !stmm_find( pMan->tTable, (char *)Key, (char ***)&ppList ) )
        return 1; 
    // the entry with this truth table is found
    pPrev = NULL;
    for ( pGate = *ppList, pGate2 = pGate? pGate->pNext: NULL; pGate; 
        pGate = pGate2, pGate2 = pGate? pGate->pNext: NULL )
    {
        pMan->nLookups++;
        if ( pGate->uTruth[0] != uTruth[0] || pGate->uTruth[1] != uTruth[1] )
        {
            pMan->nAliases++;
            continue;
        }
        fGateIsBetter = 0;
        fNewIsBetter  = 0;
        if ( pGate->Area + SUPER_EPSILON < Area )
            fGateIsBetter = 1;
        else if ( pGate->Area > Area + SUPER_EPSILON )
            fNewIsBetter = 1;
        for ( i = 0; i < nPins; i++ )
        {
            if ( pGate->ptDelays[i] == SUPER_NO_VAR || tPinDelaysRes[i] == SUPER_NO_VAR )
                continue;
            if ( pGate->ptDelays[i] + SUPER_EPSILON < tPinDelaysRes[i] )
                fGateIsBetter = 1;
            else if ( pGate->ptDelays[i] > tPinDelaysRes[i] + SUPER_EPSILON )
                fNewIsBetter = 1;
            if ( fGateIsBetter && fNewIsBetter )
                break;
        }
        // consider 4 cases
        if ( fGateIsBetter && fNewIsBetter ) // Pareto points; save both
            pPrev = pGate;
        else if ( fNewIsBetter ) // gate is worse; remove the gate
        {
            if ( pPrev == NULL )
                *ppList = pGate->pNext;
            else
                pPrev->pNext = pGate->pNext;
            Extra_MmFixedEntryRecycle( pMan->pMem, (char *)pGate );
            pMan->nRemoved++;
        }
        else if ( fGateIsBetter ) // new is worse, already dominated no need to see others
            return 0;
        else // if ( !fGateIsBetter && !fNewIsBetter ) // they are identical, no need to see others
            return 0;
    }
    return 1;
}


Super_Gate_t * Super_CreateGateNew( Super_Man_t * pMan, Mio_Gate_t * pRoot, Super_Gate_t ** pSupers, int nSupers, 
    unsigned uTruth[], float Area, float tPinDelaysRes[], float tDelayMax, int nPins )
{
    Super_Gate_t * pSuper;
    pSuper = (Super_Gate_t *)Extra_MmFixedEntryFetch( pMan->pMem );
    memset( pSuper, 0, sizeof(Super_Gate_t) );
    pSuper->pRoot     = pRoot;
    pSuper->uTruth[0] = uTruth[0];
    pSuper->uTruth[1] = uTruth[1];
    memcpy( pSuper->ptDelays, tPinDelaysRes, sizeof(float) * nPins );
    pSuper->Area      = Area;
    pSuper->nFanins   = nSupers;
    memcpy( pSuper->pFanins, pSupers, sizeof(Super_Gate_t *) * nSupers );
    pSuper->pNext     = NULL;
    pSuper->tDelayMax = tDelayMax;
    return pSuper;
}

Super_Man_t * Super_ManStart()
{
    Super_Man_t * pMan;
    pMan = ALLOC( Super_Man_t, 1 );
    memset( pMan, 0, sizeof(Super_Man_t) );
    pMan->pMem     = Extra_MmFixedStart( sizeof(Super_Gate_t) );
    pMan->tTable   = stmm_init_table( st_ptrcmp, st_ptrhash );
    return pMan;
}

void Super_ManStop( Super_Man_t * pMan )
{
    Extra_MmFixedStop( pMan->pMem );
    if ( pMan->tTable ) stmm_free_table( pMan->tTable );
    FREE( pMan->pGates );
    free( pMan );
}





void Super_Write( Super_Man_t * pMan )
{
    Super_Gate_t * pGateRoot, * pGate;
    stmm_generator * gen;
    int fZeroFound, clk, v;
    unsigned Key;

    if ( pMan->nGates < 1 )
    {
        printf( "The generated library is empty. No output file written.\n" );
        return;
    }

    // Filters the supergates by removing those that have fewer inputs than 
    // the given limit, provided that the inputs are not consequtive. 
    // For example, NAND2(a,c) is removed, but NAND2(a,b) is left, 
    // because a and b are consequtive.
    FREE( pMan->pGates );
    pMan->pGates = ALLOC( Super_Gate_t *, pMan->nAdded );
    pMan->nGates = 0;
    stmm_foreach_item( pMan->tTable, gen, (char **)&Key, (char **)&pGateRoot )
    {
        for ( pGate = pGateRoot; pGate; pGate = pGate->pNext )
        {
            // skip the elementary variables
            if ( pGate->pRoot == NULL )
                continue;
            // skip the non-consequtive gates
            fZeroFound = 0;
            for ( v = 0; v < pMan->nVarsMax; v++ )
                if ( pGate->ptDelays[v] < SUPER_NO_VAR + SUPER_EPSILON )
                    fZeroFound = 1;
                else if ( fZeroFound )
                    break;
            if ( v < pMan->nVarsMax )
                continue;
            // save the unique gate
            pMan->pGates[ pMan->nGates++ ] = pGate;
        }
    }

clk = clock();
    // sort the supergates by truth table
    qsort( (void *)pMan->pGates, pMan->nGates, sizeof(Super_Gate_t *), 
            (int (*)(const void *, const void *)) Super_WriteCompare );
    assert( Super_WriteCompare( pMan->pGates, pMan->pGates + pMan->nGates - 1 ) <= 0 );
if ( pMan->fVerbose )
{
PRT( "Sorting", clock() - clk );
}


    // write library in the old format
clk = clock();
    if ( pMan->fWriteOldFormat )
        Super_WriteLibrary( pMan );
if ( pMan->fVerbose )
{
PRT( "Writing old format", clock() - clk );
}

    // write the tree-like structure of supergates
clk = clock();
    Super_WriteLibraryTree( pMan );
if ( pMan->fVerbose )
{
PRT( "Writing new format", clock() - clk );
}
}


void Super_WriteFileHeader( Super_Man_t * pMan, FILE * pFile )
{
    fprintf( pFile, "#\n" );
    fprintf( pFile, "# Supergate library derived for \"%s\" on %s.\n", pMan->pName, Extra_TimeStamp() );
    fprintf( pFile, "#\n" );
    fprintf( pFile, "# Command line: \"super  -i %d  -l %d  -d %.2f  -a %.2f  -t %d  %s  %s\".\n", 
        pMan->nVarsMax, pMan->nLevels, pMan->tDelayMax, pMan->tAreaMax, pMan->TimeLimit, (pMan->fSkipInv? "" : "-s"), pMan->pName );
    fprintf( pFile, "#\n" );
    fprintf( pFile, "# The number of inputs      = %10d.\n", pMan->nVarsMax );
    fprintf( pFile, "# The number of levels      = %10d.\n", pMan->nLevels );
    fprintf( pFile, "# The maximum delay         = %10.2f.\n", pMan->tDelayMax  );
    fprintf( pFile, "# The maximum area          = %10.2f.\n", pMan->tAreaMax );
    fprintf( pFile, "# The maximum runtime (sec) = %10d.\n", pMan->TimeLimit );
    fprintf( pFile, "#\n" );
    fprintf( pFile, "# The number of attempts    = %10d.\n", pMan->nTried  );
    fprintf( pFile, "# The number of supergates  = %10d.\n", pMan->nGates  );
    fprintf( pFile, "# The number of functions   = %10d.\n", pMan->nUnique );
    fprintf( pFile, "# The total functions       = %.0f (2^%d).\n", pow(2,pMan->nMints), pMan->nMints );
    fprintf( pFile, "#\n" );
    fprintf( pFile, "# Generation time (sec)     = %10.2f.\n", (float)(pMan->Time)/(float)(CLOCKS_PER_SEC) );
    fprintf( pFile, "#\n" );
    fprintf( pFile, "%s\n", pMan->pName );
    fprintf( pFile, "%d\n", pMan->nVarsMax );
    fprintf( pFile, "%d\n", pMan->nGates );
}

int Super_WriteCompare( Super_Gate_t ** ppG1, Super_Gate_t ** ppG2 )
{
    unsigned * pTruth1 = (*ppG1)->uTruth;
    unsigned * pTruth2 = (*ppG2)->uTruth;
    if ( pTruth1[1] < pTruth2[1] )
        return -1;
    if ( pTruth1[1] > pTruth2[1] )
        return 1;
    if ( pTruth1[0] < pTruth2[0] )
        return -1;
    if ( pTruth1[0] > pTruth2[0] )
        return 1;
    return 0;
}

int Super_DelayCompare( Super_Gate_t ** ppG1, Super_Gate_t ** ppG2 )
{
    if ( (*ppG1)->tDelayMax < (*ppG2)->tDelayMax )
        return -1;
    if ( (*ppG1)->tDelayMax > (*ppG2)->tDelayMax )
        return 1;
    return 0;
}

int Super_AreaCompare( Super_Gate_t ** ppG1, Super_Gate_t ** ppG2 )
{
    if ( (*ppG1)->Area < (*ppG2)->Area )
        return -1;
    if ( (*ppG1)->Area > (*ppG2)->Area )
        return 1;
    return 0;
}






void Super_WriteLibrary( Super_Man_t * pMan )
{
    Super_Gate_t * pGate, * pGateNext;
    FILE * pFile;
    char FileName[100];
    char * pNameGeneric;
    int i, Counter;

    // get the file name
    pNameGeneric = Extra_FileNameGeneric( pMan->pName );
    sprintf( FileName, "%s.super_old", pNameGeneric );
    free( pNameGeneric );

    // count the number of unique functions
    pMan->nUnique = 1;
    Super_ManForEachGate( pMan->pGates, pMan->nGates, i, pGate )
    {
        if ( i == pMan->nGates - 1 )
            break;
        // print the newline if this gate is different from the following one
        pGateNext = pMan->pGates[i+1];
        if ( pGateNext->uTruth[0] != pGate->uTruth[0] || pGateNext->uTruth[1] != pGate->uTruth[1] )
            pMan->nUnique++;
    }

    // start the file
    pFile = fopen( FileName, "w" );
    Super_WriteFileHeader( pMan, pFile );

    // print the gates
    Counter = 0;
    Super_ManForEachGate( pMan->pGates, pMan->nGates, i, pGate )
    {
        Super_WriteLibraryGate( pFile, pMan, pGate, ++Counter );
        if ( i == pMan->nGates - 1 )
            break;
        // print the newline if this gate is different from the following one
        pGateNext = pMan->pGates[i+1];
        if ( pGateNext->uTruth[0] != pGate->uTruth[0] || pGateNext->uTruth[1] != pGate->uTruth[1] )
            fprintf( pFile, "\n" );
    }
    assert( Counter == pMan->nGates );
    fclose( pFile );

if ( pMan->fVerbose )
{
    printf( "The supergates are written using old format \"%s\" ", FileName );
    printf( "(%0.3f Mb).\n", ((double)Extra_FileSize(FileName))/(1<<20) );
}
}

void Super_WriteLibraryGate( FILE * pFile, Super_Man_t * pMan, Super_Gate_t * pGate, int Num )
{
    int i;
    fprintf( pFile, "%04d  ", Num );                         // the number
    Extra_PrintBinary( pFile, pGate->uTruth, pMan->nMints ); // the truth table
    fprintf( pFile, "   %5.2f", pGate->tDelayMax );          // the max delay
    fprintf( pFile, "  " );                                  
    for ( i = 0; i < pMan->nVarsMax; i++ )                   // the pin-to-pin delays
        fprintf( pFile, " %5.2f", pGate->ptDelays[i]==SUPER_NO_VAR? 0.0 : pGate->ptDelays[i] );  
    fprintf( pFile, "   %5.2f", pGate->Area );               // the area
    fprintf( pFile, "   " );
    fprintf( pFile, "%s", Super_WriteLibraryGateName(pGate) );      // the symbolic expression
    fprintf( pFile, "\n" );
}

char * Super_WriteLibraryGateName( Super_Gate_t * pGate )
{
    static char Buffer[2000];
    Buffer[0] = 0;
    Super_WriteLibraryGateName_rec( pGate, Buffer );
    return Buffer;
}

void Super_WriteLibraryGateName_rec( Super_Gate_t * pGate, char * pBuffer )
{
    char Buffer[10];
    int i;

    if ( pGate->pRoot == NULL )
    {
        sprintf( Buffer, "%c", 'a' + pGate->Number );
        strcat( pBuffer, Buffer );
        return;
    }
    strcat( pBuffer, Mio_GateReadName(pGate->pRoot) );
    strcat( pBuffer, "(" );
    for ( i = 0; i < (int)pGate->nFanins; i++ )
    {
        if ( i )
            strcat( pBuffer, "," );
        Super_WriteLibraryGateName_rec( pGate->pFanins[i], pBuffer );
    }
    strcat( pBuffer, ")" );
}





void Super_WriteLibraryTree( Super_Man_t * pMan )
{
    Super_Gate_t * pSuper;
    FILE * pFile;
    char FileName[100];
    char * pNameGeneric;
    int i, Counter;
    int posStart;

    // get the file name
    pNameGeneric = Extra_FileNameGeneric( pMan->pName );
    sprintf( FileName, "%s.super", pNameGeneric );
    free( pNameGeneric );
 
    // write the elementary variables
    pFile = fopen( FileName, "w" );
    Super_WriteFileHeader( pMan, pFile );
    // write the place holder for the number of lines
    posStart = ftell( pFile );
    fprintf( pFile, "         \n" );
    // mark the real supergates
    Super_ManForEachGate( pMan->pGates, pMan->nGates, i, pSuper )
        pSuper->fSuper = 1;
    // write the supergates
    Counter = pMan->nVarsMax;
    Super_ManForEachGate( pMan->pGates, pMan->nGates, i, pSuper )
        Super_WriteLibraryTree_rec( pFile, pMan, pSuper, &Counter );
    fclose( pFile );
    // write the number of lines
    pFile = fopen( FileName, "rb+" );
    fseek( pFile, posStart, SEEK_SET );
    fprintf( pFile, "%d", Counter );
    fclose( pFile );

if ( pMan->fVerbose )
{
    printf( "The supergates are written using new format \"%s\" ", FileName );
    printf( "(%0.3f Mb).\n", ((double)Extra_FileSize(FileName))/(1<<20) );
}
}

void Super_WriteLibraryTree_rec( FILE * pFile, Super_Man_t * pMan, Super_Gate_t * pSuper, int * pCounter )
{
    int nFanins, i;
    // skip an elementary variable and a gate that was already written
    if ( pSuper->fVar || pSuper->Number > 0 )
        return;
    // write the fanins
    nFanins = Mio_GateReadInputs(pSuper->pRoot);
    for ( i = 0; i < nFanins; i++ )
        Super_WriteLibraryTree_rec( pFile, pMan, pSuper->pFanins[i], pCounter );
    // finally write the gate
    pSuper->Number = (*pCounter)++;
    fprintf( pFile, "%s", pSuper->fSuper? "* " : "" );
    fprintf( pFile, "%s", Mio_GateReadName(pSuper->pRoot) );
    for ( i = 0; i < nFanins; i++ )
        fprintf( pFile, " %d", pSuper->pFanins[i]->Number );
    // write the formula 
    // this step is optional, the resulting library will work in any case
    // however, it may be helpful to for debugging to compare the same library 
    // written in the old format and written in the new format with formulas
//    fprintf( pFile, "    # %s", Super_WriteLibraryGateName( pSuper ) );
    fprintf( pFile, "\n" );
}

---