src/aig/ivy/ivyTable.c

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#include "ivy.h"


// hashing the node
static unsigned Ivy_Hash( Ivy_Obj_t * pObj, int TableSize ) 
{
    unsigned Key = Ivy_ObjIsExor(pObj) * 1699;
    Key ^= Ivy_ObjFaninId0(pObj) * 7937;
    Key ^= Ivy_ObjFaninId1(pObj) * 2971;
    Key ^= Ivy_ObjFaninC0(pObj) * 911;
    Key ^= Ivy_ObjFaninC1(pObj) * 353;
    Key ^= Ivy_ObjInit(pObj) * 911;
    return Key % TableSize;
}

// returns the place where this node is stored (or should be stored)
static int * Ivy_TableFind( Ivy_Man_t * p, Ivy_Obj_t * pObj )
{
    int i;
    assert( Ivy_ObjIsHash(pObj) );
    for ( i = Ivy_Hash(pObj, p->nTableSize); p->pTable[i]; i = (i+1) % p->nTableSize )
        if ( p->pTable[i] == pObj->Id )
            break;
    return p->pTable + i;
}

static void         Ivy_TableResize( Ivy_Man_t * p );
static unsigned int Cudd_PrimeAig( unsigned int  p );

 
Ivy_Obj_t * Ivy_TableLookup( Ivy_Man_t * p, Ivy_Obj_t * pObj )
{
    Ivy_Obj_t * pEntry;
    int i;
    assert( !Ivy_IsComplement(pObj) );
    if ( !Ivy_ObjIsHash(pObj) )
        return NULL;
    assert( Ivy_ObjIsLatch(pObj) || Ivy_ObjFaninId0(pObj) > 0 );
    assert( Ivy_ObjFaninId1(pObj) == 0 || Ivy_ObjFaninId0(pObj) < Ivy_ObjFaninId1(pObj) );
    if ( Ivy_ObjFanin0(pObj)->nRefs == 0 || (Ivy_ObjChild1(pObj) && Ivy_ObjFanin1(pObj)->nRefs == 0) )
        return NULL;
    for ( i = Ivy_Hash(pObj, p->nTableSize); p->pTable[i]; i = (i+1) % p->nTableSize )
    {
        pEntry = Ivy_ManObj( p, p->pTable[i] );
        if ( Ivy_ObjChild0(pEntry) == Ivy_ObjChild0(pObj) && 
             Ivy_ObjChild1(pEntry) == Ivy_ObjChild1(pObj) && 
             Ivy_ObjInit(pEntry) == Ivy_ObjInit(pObj) && 
             Ivy_ObjType(pEntry) == Ivy_ObjType(pObj) )
            return pEntry;
    }
    return NULL;
}

void Ivy_TableInsert( Ivy_Man_t * p, Ivy_Obj_t * pObj )
{
    int * pPlace;
    assert( !Ivy_IsComplement(pObj) );
    if ( !Ivy_ObjIsHash(pObj) )
        return;
    if ( (pObj->Id & 63) == 0 )
    {
        if ( p->nTableSize < 2 * Ivy_ManHashObjNum(p) )
            Ivy_TableResize( p );
    }
    pPlace = Ivy_TableFind( p, pObj );
    assert( *pPlace == 0 );
    *pPlace = pObj->Id;
}

void Ivy_TableDelete( Ivy_Man_t * p, Ivy_Obj_t * pObj )
{
    Ivy_Obj_t * pEntry;
    int i, * pPlace;
    assert( !Ivy_IsComplement(pObj) );
    if ( !Ivy_ObjIsHash(pObj) )
        return;
    pPlace = Ivy_TableFind( p, pObj );
    assert( *pPlace == pObj->Id ); // node should be in the table
    *pPlace = 0;
    // rehash the adjacent entries
    i = pPlace - p->pTable;
    for ( i = (i+1) % p->nTableSize; p->pTable[i]; i = (i+1) % p->nTableSize )
    {
        pEntry = Ivy_ManObj( p, p->pTable[i] );
        p->pTable[i] = 0;
        Ivy_TableInsert( p, pEntry );
    }
}

void Ivy_TableUpdate( Ivy_Man_t * p, Ivy_Obj_t * pObj, int ObjIdNew )
{
    int * pPlace;
    assert( !Ivy_IsComplement(pObj) );
    if ( !Ivy_ObjIsHash(pObj) )
        return;
    pPlace = Ivy_TableFind( p, pObj );
    assert( *pPlace == pObj->Id ); // node should be in the table
    *pPlace = ObjIdNew; 
}

int Ivy_TableCountEntries( Ivy_Man_t * p )
{
    int i, Counter = 0;
    for ( i = 0; i < p->nTableSize; i++ )
        Counter += (p->pTable[i] != 0);
    return Counter;
}

void Ivy_TableResize( Ivy_Man_t * p )
{
    int * pTableOld, * pPlace;
    int nTableSizeOld, Counter, nEntries, e, clk;
clk = clock();
    // save the old table
    pTableOld = p->pTable;
    nTableSizeOld = p->nTableSize;
    // get the new table
    p->nTableSize = Cudd_PrimeAig( 5 * Ivy_ManHashObjNum(p) ); 
    p->pTable = ALLOC( int, p->nTableSize );
    memset( p->pTable, 0, sizeof(int) * p->nTableSize );
    // rehash the entries from the old table
    Counter = 0;
    for ( e = 0; e < nTableSizeOld; e++ )
    {
        if ( pTableOld[e] == 0 )
            continue;
        Counter++;
        // get the place where this entry goes in the table table
        pPlace = Ivy_TableFind( p, Ivy_ManObj(p, pTableOld[e]) );
        assert( *pPlace == 0 ); // should not be in the table
        *pPlace = pTableOld[e];
    }
    nEntries = Ivy_ManHashObjNum(p);
//    assert( Counter == nEntries );
//    printf( "Increasing the structural table size from %6d to %6d. ", nTableSizeOld, p->nTableSize );
//    PRT( "Time", clock() - clk );
    // replace the table and the parameters
    free( pTableOld );
}

void Ivy_TableProfile( Ivy_Man_t * p )
{
    int i, Counter = 0;
    for ( i = 0; i < p->nTableSize; i++ )
    {
        if ( p->pTable[i] )
            Counter++;
        else if ( Counter )
        {
            printf( "%d ", Counter );
            Counter = 0;
        }
    }
}

unsigned int Cudd_PrimeAig( unsigned int  p)
{
    int i,pn;

    p--;
    do {
        p++;
        if (p&1) {
            pn = 1;
            i = 3;
            while ((unsigned) (i * i) <= p) {
                if (p % i == 0) {
                    pn = 0;
                    break;
                }
                i += 2;
            }
        } else {
            pn = 0;
        }
    } while (!pn);
    return(p);

} /* end of Cudd_Prime */

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