llb1Hint.c 6.8 KB
Newer Older
1 2
/**CFile****************************************************************

3
  FileName    [llb1Hint.c]
4 5 6 7 8 9 10 11 12 13 14 15 16

  SystemName  [ABC: Logic synthesis and verification system.]

  PackageName [BDD based reachability.]

  Synopsis    [Cofactors the circuit w.r.t. the high-fanout variables.]

  Author      [Alan Mishchenko]
  
  Affiliation [UC Berkeley]

  Date        [Ver. 1.0. Started - June 20, 2005.]

17
  Revision    [$Id: llb1Hint.c,v 1.00 2005/06/20 00:00:00 alanmi Exp $]
18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48

***********************************************************************/

#include "llbInt.h"

ABC_NAMESPACE_IMPL_START


////////////////////////////////////////////////////////////////////////
///                        DECLARATIONS                              ///
////////////////////////////////////////////////////////////////////////

////////////////////////////////////////////////////////////////////////
///                     FUNCTION DEFINITIONS                         ///
////////////////////////////////////////////////////////////////////////

/**Function*************************************************************

  Synopsis    [Returns CI index with the largest number of fanouts.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
int Llb_ManMaxFanoutCi( Aig_Man_t * pAig )
{
    Aig_Obj_t * pObj; 
    int i, WeightMax = -ABC_INFINITY, iInput = -1;
49
    Aig_ManForEachCi( pAig, pObj, i )
50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105
        if ( WeightMax < Aig_ObjRefs(pObj) )
        {
            WeightMax = Aig_ObjRefs(pObj);
            iInput = i;
        }
    assert( iInput >= 0 );
    return iInput;
}

/**Function*************************************************************

  Synopsis    [Derives AIG whose PI is substituted by a constant.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
Aig_Man_t * Llb_ManPerformHints( Aig_Man_t * pAig, int nHintDepth )
{
    Aig_Man_t * pNew, * pTemp;
    int i, iInput;
    pNew = Aig_ManDupDfs( pAig );
    for ( i = 0; i < nHintDepth; i++ )
    {
        iInput = Llb_ManMaxFanoutCi( pNew );
        Abc_Print( 1, "%d %3d\n", i, iInput );
        pNew = Aig_ManDupCof( pTemp = pNew, iInput, 1 );
        Aig_ManStop( pTemp );
    }
    return pNew;
}

/**Function*************************************************************

  Synopsis    [Returns CI index with the largest number of fanouts.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
Vec_Int_t * Llb_ManCollectHighFanoutObjects( Aig_Man_t * pAig, int nCandMax, int fCisOnly )
{
    Vec_Int_t * vFanouts, * vResult;
    Aig_Obj_t * pObj; 
    int i, fChanges, PivotValue;
//    int Entry;
    // collect fanout counts
    vFanouts = Vec_IntAlloc( 100 );
    Aig_ManForEachObj( pAig, pObj, i )
    {
106
//        if ( !Aig_ObjIsCi(pObj) && (fCisOnly || !Aig_ObjIsNode(pObj)) )
107 108 109 110 111 112
        if ( !Saig_ObjIsLo(pAig,pObj) && (fCisOnly || !Aig_ObjIsNode(pObj)) )
            continue;
        Vec_IntPush( vFanouts, Aig_ObjRefs(pObj) );
    }
    Vec_IntSort( vFanouts, 1 );
    // pick the separator
113
    nCandMax = Abc_MinInt( nCandMax, Vec_IntSize(vFanouts) - 1 );
114 115 116 117 118 119
    PivotValue = Vec_IntEntry( vFanouts, nCandMax );
    Vec_IntFree( vFanouts );
    // collect obj satisfying the constraints
    vResult = Vec_IntAlloc( 100 );
    Aig_ManForEachObj( pAig, pObj, i )
    {
120
//        if ( !Aig_ObjIsCi(pObj) && (fCisOnly || !Aig_ObjIsNode(pObj)) )
121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167
        if ( !Saig_ObjIsLo(pAig,pObj) && (fCisOnly || !Aig_ObjIsNode(pObj)) )
            continue;
        if ( Aig_ObjRefs(pObj) < PivotValue )
            continue;
        Vec_IntPush( vResult, Aig_ObjId(pObj) );
    }
    assert( Vec_IntSize(vResult) >= nCandMax );
    // order in the decreasing order of fanouts
    do
    {
        fChanges = 0;
        for ( i = 0; i < Vec_IntSize(vResult) - 1; i++ )
            if ( Aig_ObjRefs(Aig_ManObj(pAig, Vec_IntEntry(vResult, i))) < 
                 Aig_ObjRefs(Aig_ManObj(pAig, Vec_IntEntry(vResult, i+1))) )
            {
                int Temp = Vec_IntEntry( vResult, i );
                Vec_IntWriteEntry( vResult, i, Vec_IntEntry(vResult, i+1) );
                Vec_IntWriteEntry( vResult, i+1, Temp );
                fChanges = 1;
            }
    }
    while ( fChanges );
/*
    Vec_IntForEachEntry( vResult, Entry, i )
        printf( "%d ", Aig_ObjRefs(Aig_ManObj(pAig, Entry)) );
printf( "\n" );
*/
    return vResult;
}

/**Function*************************************************************

  Synopsis    [Derives AIG whose PI is substituted by a constant.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
int Llb_ManModelCheckAigWithHints( Aig_Man_t * pAigGlo, Gia_ParLlb_t * pPars )
{
    DdManager * ddGlo = NULL;
    Vec_Int_t * vHints;
    Vec_Int_t * vHFCands;
    int i, Entry, RetValue = -1;
168
    abctime clk = Abc_Clock();
169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207
    assert( pPars->nHintDepth > 0 );
/*
    // perform reachability without hints
    RetValue = Llb_ManModelCheckAig( pAigGlo, pPars, NULL, NULL );
    if ( RetValue >= 0 )
        return RetValue;
*/
    // create hints representation
    vHFCands = Llb_ManCollectHighFanoutObjects( pAigGlo, pPars->nHintDepth+pPars->HintFirst, 1 );
    vHints   = Vec_IntStartFull( Aig_ManObjNumMax(pAigGlo) );
    // add one hint at a time till the problem is solved
    Vec_IntForEachEntryStart( vHFCands, Entry, i, pPars->HintFirst )
    {
        Vec_IntWriteEntry( vHints, Entry, 1 );   // change to 1 to start from zero cof!!!
        // solve under hints
        RetValue = Llb_ManModelCheckAig( pAigGlo, pPars, vHints, &ddGlo );
        if ( RetValue == 0 )
            goto Finish;
        if ( RetValue == 1 )
            break;
    }
    if ( RetValue == -1 )
        goto Finish;
    // undo the hints one at a time
    for ( ; i >= pPars->HintFirst; i-- )
    {
        Entry = Vec_IntEntry( vHFCands, i );
        Vec_IntWriteEntry( vHints, Entry, -1 );        
        // solve under relaxed hints
        RetValue = Llb_ManModelCheckAig( pAigGlo, pPars, vHints, &ddGlo );
        if ( RetValue == 0 )
            goto Finish;
        if ( RetValue == 1 )
            continue;
        break;
    }
Finish:
    if ( ddGlo )
    {
208 209
        if ( ddGlo->bFunc )
            Cudd_RecursiveDeref( ddGlo, ddGlo->bFunc ); 
210 211 212 213 214
        Extra_StopManager( ddGlo );
    }
    Vec_IntFreeP( &vHFCands );
    Vec_IntFreeP( &vHints );
    if ( pPars->fVerbose )
215
        Abc_PrintTime( 1, "Total runtime", Abc_Clock() - clk );
216 217 218 219 220 221 222 223 224 225 226
    return RetValue;
}


////////////////////////////////////////////////////////////////////////
///                       END OF FILE                                ///
////////////////////////////////////////////////////////////////////////


ABC_NAMESPACE_IMPL_END