src/base/abci/abcSymm.c

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#include "abc.h"

 
static void Abc_NtkSymmetriesUsingBdds( Abc_Ntk_t * pNtk, int fNaive, int fReorder, int fVerbose );
static void Abc_NtkSymmetriesUsingSandS( Abc_Ntk_t * pNtk, int fVerbose );
static void Ntk_NetworkSymmsBdd( DdManager * dd, Abc_Ntk_t * pNtk, int fNaive, int fVerbose );
static void Ntk_NetworkSymmsPrint( Abc_Ntk_t * pNtk, Extra_SymmInfo_t * pSymms );


void Abc_NtkSymmetries( Abc_Ntk_t * pNtk, int fUseBdds, int fNaive, int fReorder, int fVerbose )
{
    if ( fUseBdds || fNaive )
        Abc_NtkSymmetriesUsingBdds( pNtk, fNaive, fReorder, fVerbose );
    else
        Abc_NtkSymmetriesUsingSandS( pNtk, fVerbose );
}

void Abc_NtkSymmetriesUsingSandS( Abc_Ntk_t * pNtk, int fVerbose )
{
    extern int Sim_ComputeTwoVarSymms( Abc_Ntk_t * pNtk, int fVerbose );
    int nSymms = Sim_ComputeTwoVarSymms( pNtk, fVerbose );
    printf( "The total number of symmetries is %d.\n", nSymms );
}

void Abc_NtkSymmetriesUsingBdds( Abc_Ntk_t * pNtk, int fNaive, int fReorder, int fVerbose )
{
    DdManager * dd;
    int clk, clkBdd, clkSym;
    int fGarbCollect = 1;

    // compute the global functions
clk = clock();
    dd = Abc_NtkBuildGlobalBdds( pNtk, 10000000, 1, fReorder, fVerbose );
    printf( "Shared BDD size = %d nodes.\n", Abc_NtkSizeOfGlobalBdds(pNtk) ); 
    Cudd_AutodynDisable( dd );
    if ( !fGarbCollect )
        Cudd_DisableGarbageCollection( dd );
    Cudd_zddVarsFromBddVars( dd, 2 );
clkBdd = clock() - clk;
    // create the collapsed network
clk = clock();
    Ntk_NetworkSymmsBdd( dd, pNtk, fNaive, fVerbose );
clkSym = clock() - clk;
    // undo the global functions
    Abc_NtkFreeGlobalBdds( pNtk, 1 );
printf( "Statistics of BDD-based symmetry detection:\n" );
printf( "Algorithm = %s. Reordering = %s. Garbage collection = %s.\n", 
       fNaive? "naive" : "fast", fReorder? "yes" : "no", fGarbCollect? "yes" : "no" );
PRT( "Constructing BDDs", clkBdd );
PRT( "Computing symms  ", clkSym );
PRT( "TOTAL            ", clkBdd + clkSym );
}

void Ntk_NetworkSymmsBdd( DdManager * dd, Abc_Ntk_t * pNtk, int fNaive, int fVerbose )
{
    Extra_SymmInfo_t * pSymms;
    Abc_Obj_t * pNode;
    DdNode * bFunc;
    int nSymms = 0;
    int nSupps = 0;
    int i;

    // compute symmetry info for each PO
    Abc_NtkForEachCo( pNtk, pNode, i )
    {
//      bFunc = pNtk->vFuncsGlob->pArray[i];
        bFunc = Abc_ObjGlobalBdd( pNode );
        nSupps += Cudd_SupportSize( dd, bFunc );
        if ( Cudd_IsConstant(bFunc) )
            continue;
        if ( fNaive )
            pSymms = Extra_SymmPairsComputeNaive( dd, bFunc );
        else
            pSymms = Extra_SymmPairsCompute( dd, bFunc );
        nSymms += pSymms->nSymms;
        if ( fVerbose )
        {
            printf( "Output %6s (%d): ", Abc_ObjName(pNode), pSymms->nSymms );
            Ntk_NetworkSymmsPrint( pNtk, pSymms );
        }
//Extra_SymmPairsPrint( pSymms );
        Extra_SymmPairsDissolve( pSymms );
    }
    printf( "Total number of vars in functional supports = %8d.\n", nSupps );
    printf( "Total number of two-variable symmetries     = %8d.\n", nSymms );
}

void Ntk_NetworkSymmsPrint( Abc_Ntk_t * pNtk, Extra_SymmInfo_t * pSymms )
{
    char ** pInputNames;
    int * pVarTaken;
    int i, k, nVars, nSize, fStart;

    // get variable names
    nVars = Abc_NtkCiNum(pNtk);
    pInputNames = Abc_NtkCollectCioNames( pNtk, 0 );

    // alloc the array of marks
    pVarTaken = ALLOC( int, nVars );
    memset( pVarTaken, 0, sizeof(int) * nVars );

    // print the groups
    fStart = 1;
    nSize = pSymms->nVars;
    for ( i = 0; i < nSize; i++ )
    {
        // skip the variable already considered
        if ( pVarTaken[i] )
            continue;
        // find all the vars symmetric with this one
        for ( k = 0; k < nSize; k++ )
        {
            if ( k == i )
                continue;
            if ( pSymms->pSymms[i][k] == 0 )
                continue;
            // vars i and k are symmetric
            assert( pVarTaken[k] == 0 );
            // there is a new symmetry pair 
            if ( fStart == 1 )
            {  // start a new symmetry class
                fStart = 0;
                printf( "  { %s", pInputNames[ pSymms->pVars[i] ] );
                // mark the var as taken
                pVarTaken[i] = 1;
            }
            printf( " %s", pInputNames[ pSymms->pVars[k] ] );
            // mark the var as taken
            pVarTaken[k] = 1;
        }
        if ( fStart == 0 )
        {
            printf( " }" );
            fStart = 1; 
        }   
    }   
    printf( "\n" );

    free( pInputNames );
    free( pVarTaken );
}

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