src/sat/fraig/fraigNode.c

Go to the documentation of this file.

#include "fraigInt.h"


// returns the complemented attribute of the node
#define Fraig_NodeIsSimComplement(p) (Fraig_IsComplement(p)? !(Fraig_Regular(p)->fInv) : (p)->fInv)


Fraig_Node_t * Fraig_NodeCreateConst( Fraig_Man_t * p )
{
    Fraig_Node_t * pNode;

    // create the node
    pNode = (Fraig_Node_t *)Fraig_MemFixedEntryFetch( p->mmNodes );
    memset( pNode, 0, sizeof(Fraig_Node_t) );

    // assign the number and add to the array of nodes
    pNode->Num   = p->vNodes->nSize;
    Fraig_NodeVecPush( p->vNodes,  pNode );
    pNode->NumPi = -1;  // this is not a PI, so its number is -1
    pNode->Level =  0;  // just like a PI, it has 0 level
    pNode->nRefs =  1;  // it is a persistent node, which comes referenced
    pNode->fInv  =  1;  // the simulation info is complemented

    // create the simulation info
    pNode->puSimR = (unsigned *)Fraig_MemFixedEntryFetch( p->mmSims );
    pNode->puSimD = pNode->puSimR + p->nWordsRand;
    memset( pNode->puSimR, 0, sizeof(unsigned) * p->nWordsRand );
    memset( pNode->puSimD, 0, sizeof(unsigned) * p->nWordsDyna );

    // count the number of ones in the simulation vector
    pNode->nOnes = p->nWordsRand * sizeof(unsigned) * 8;

    // insert it into the hash table
    Fraig_HashTableLookupF0( p, pNode );
    return pNode;
}

Fraig_Node_t * Fraig_NodeCreatePi( Fraig_Man_t * p )
{
    Fraig_Node_t * pNode, * pNodeRes;
    int i, clk;

    // create the node
    pNode = (Fraig_Node_t *)Fraig_MemFixedEntryFetch( p->mmNodes );
    memset( pNode, 0, sizeof(Fraig_Node_t) );
    pNode->puSimR = (unsigned *)Fraig_MemFixedEntryFetch( p->mmSims );
    pNode->puSimD = pNode->puSimR + p->nWordsRand;
    memset( pNode->puSimD, 0, sizeof(unsigned) * p->nWordsDyna );

    // assign the number and add to the array of nodes
    pNode->Num   = p->vNodes->nSize;
    Fraig_NodeVecPush( p->vNodes,  pNode );

    // assign the PI number and add to the array of primary inputs
    pNode->NumPi = p->vInputs->nSize;   
    Fraig_NodeVecPush( p->vInputs, pNode );

    pNode->Level =  0;  // PI has 0 level
    pNode->nRefs =  1;  // it is a persistent node, which comes referenced
    pNode->fInv  =  0;  // the simulation info of the PI is not complemented

    // derive the simulation info for the new node
clk = clock();
    // set the random simulation info for the primary input
    pNode->uHashR = 0;
    for ( i = 0; i < p->nWordsRand; i++ )
    {
        // generate the simulation info
        pNode->puSimR[i] = FRAIG_RANDOM_UNSIGNED;
        // for reasons that take very long to explain, it makes sense to have (0000000...) 
        // pattern in the set (this helps if we need to return the counter-examples)
        if ( i == 0 )
            pNode->puSimR[i] <<= 1;
        // compute the hash key
        pNode->uHashR ^= pNode->puSimR[i] * s_FraigPrimes[i];
    }
    // count the number of ones in the simulation vector
    pNode->nOnes = Fraig_BitStringCountOnes( pNode->puSimR, p->nWordsRand );

    // set the systematic simulation info for the primary input
    pNode->uHashD = 0;
    for ( i = 0; i < p->iWordStart; i++ )
    {
        // generate the simulation info
        pNode->puSimD[i] = FRAIG_RANDOM_UNSIGNED;
        // compute the hash key
        pNode->uHashD ^= pNode->puSimD[i] * s_FraigPrimes[i];
    }
p->timeSims += clock() - clk;

    // insert it into the hash table
    pNodeRes = Fraig_HashTableLookupF( p, pNode );
    assert( pNodeRes == NULL );
    // add to the runtime of simulation
    return pNode;
}

Fraig_Node_t * Fraig_NodeCreate( Fraig_Man_t * p, Fraig_Node_t * p1, Fraig_Node_t * p2 )
{
    Fraig_Node_t * pNode;
    int clk;

    // create the node
    pNode = (Fraig_Node_t *)Fraig_MemFixedEntryFetch( p->mmNodes );
    memset( pNode, 0, sizeof(Fraig_Node_t) );

    // assign the children
    pNode->p1  = p1;  Fraig_Ref(p1);  Fraig_Regular(p1)->nRefs++;
    pNode->p2  = p2;  Fraig_Ref(p2);  Fraig_Regular(p2)->nRefs++;

    // assign the number and add to the array of nodes
    pNode->Num = p->vNodes->nSize;
    Fraig_NodeVecPush( p->vNodes,  pNode );

    // assign the PI number
    pNode->NumPi = -1;

    // compute the level of this node
    pNode->Level = 1 + FRAIG_MAX(Fraig_Regular(p1)->Level, Fraig_Regular(p2)->Level);
    pNode->fInv  = Fraig_NodeIsSimComplement(p1) & Fraig_NodeIsSimComplement(p2);
    pNode->fFailTfo = Fraig_Regular(p1)->fFailTfo | Fraig_Regular(p2)->fFailTfo;

    // derive the simulation info 
clk = clock();
    // allocate memory for the simulation info
    pNode->puSimR = (unsigned *)Fraig_MemFixedEntryFetch( p->mmSims );
    pNode->puSimD = pNode->puSimR + p->nWordsRand;
    // derive random simulation info
    pNode->uHashR = 0;
    Fraig_NodeSimulate( pNode, 0, p->nWordsRand, 1 );
    // derive dynamic simulation info
    pNode->uHashD = 0;
    Fraig_NodeSimulate( pNode, 0, p->iWordStart, 0 );
    // count the number of ones in the random simulation info
    pNode->nOnes = Fraig_BitStringCountOnes( pNode->puSimR, p->nWordsRand );
    if ( pNode->fInv )
        pNode->nOnes = p->nWordsRand * 32 - pNode->nOnes;
    // add to the runtime of simulation
p->timeSims += clock() - clk;

#ifdef FRAIG_ENABLE_FANOUTS
    // create the fanout info
    Fraig_NodeAddFaninFanout( Fraig_Regular(p1), pNode );
    Fraig_NodeAddFaninFanout( Fraig_Regular(p2), pNode );
#endif
    return pNode;
}


void Fraig_NodeSimulate( Fraig_Node_t * pNode, int iWordStart, int iWordStop, int fUseRand )
{
    unsigned * pSims, * pSims1, * pSims2;
    unsigned uHash;
    int fCompl, fCompl1, fCompl2, i;

    assert( !Fraig_IsComplement(pNode) );

    // get hold of the simulation information
    pSims  = fUseRand? pNode->puSimR                    : pNode->puSimD;
    pSims1 = fUseRand? Fraig_Regular(pNode->p1)->puSimR : Fraig_Regular(pNode->p1)->puSimD;
    pSims2 = fUseRand? Fraig_Regular(pNode->p2)->puSimR : Fraig_Regular(pNode->p2)->puSimD;

    // get complemented attributes of the children using their random info
    fCompl  = pNode->fInv;
    fCompl1 = Fraig_NodeIsSimComplement(pNode->p1);
    fCompl2 = Fraig_NodeIsSimComplement(pNode->p2);

    // simulate
    uHash = 0;
    if ( fCompl1 && fCompl2 )
    {
        if ( fCompl )
            for ( i = iWordStart; i < iWordStop; i++ )
            {
                pSims[i] = (pSims1[i] | pSims2[i]);
                uHash ^= pSims[i] * s_FraigPrimes[i];
            }
        else
            for ( i = iWordStart; i < iWordStop; i++ )
            {
                pSims[i] = ~(pSims1[i] | pSims2[i]);
                uHash ^= pSims[i] * s_FraigPrimes[i];
            }
    }
    else if ( fCompl1 && !fCompl2 )
    {
        if ( fCompl )
            for ( i = iWordStart; i < iWordStop; i++ )
            {
                pSims[i] = (pSims1[i] | ~pSims2[i]);
                uHash ^= pSims[i] * s_FraigPrimes[i];
            }
        else
            for ( i = iWordStart; i < iWordStop; i++ )
            {
                pSims[i] = (~pSims1[i] & pSims2[i]);
                uHash ^= pSims[i] * s_FraigPrimes[i];
            }
    }
    else if ( !fCompl1 && fCompl2 )
    {
        if ( fCompl )
            for ( i = iWordStart; i < iWordStop; i++ )
            {
                pSims[i] = (~pSims1[i] | pSims2[i]);
                uHash ^= pSims[i] * s_FraigPrimes[i];
            }
        else
            for ( i = iWordStart; i < iWordStop; i++ )
            {
                pSims[i] = (pSims1[i] & ~pSims2[i]);
                uHash ^= pSims[i] * s_FraigPrimes[i];
            }
    }
    else // if ( !fCompl1 && !fCompl2 )
    {
        if ( fCompl )
            for ( i = iWordStart; i < iWordStop; i++ )
            {
                pSims[i] = ~(pSims1[i] & pSims2[i]);
                uHash ^= pSims[i] * s_FraigPrimes[i];
            }
        else
            for ( i = iWordStart; i < iWordStop; i++ )
            {
                pSims[i] = (pSims1[i] & pSims2[i]);
                uHash ^= pSims[i] * s_FraigPrimes[i];
            }
    }

    if ( fUseRand )
        pNode->uHashR ^= uHash;
    else
        pNode->uHashD ^= uHash;
}

---