/**CFile****************************************************************

  FileName    [giaResub.c]

  SystemName  [ABC: Logic synthesis and verification system.]

  PackageName [Scalable AIG package.]

  Synopsis    [Resubstitution.]

  Author      [Alan Mishchenko]
  
  Affiliation [UC Berkeley]

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

  Revision    [$Id: giaResub.c,v 1.00 2005/06/20 00:00:00 alanmi Exp $]

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

#include "gia.h"
#include "misc/vec/vecWec.h"
#include "misc/vec/vecQue.h"
#include "misc/vec/vecHsh.h"

ABC_NAMESPACE_IMPL_START


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

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

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

  Synopsis    [Computes MFFCs of all qualifying nodes.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
int Gia_ObjCheckMffc_rec( Gia_Man_t * p,Gia_Obj_t * pObj, int Limit, Vec_Int_t * vNodes )
{
    int iFanin;
    if ( Gia_ObjIsCi(pObj) )
        return 1;
    assert( Gia_ObjIsAnd(pObj) );
    iFanin = Gia_ObjFaninId0p(p, pObj);
    Vec_IntPush( vNodes, iFanin );
    if ( !Gia_ObjRefDecId(p, iFanin) && (Vec_IntSize(vNodes) > Limit || !Gia_ObjCheckMffc_rec(p, Gia_ObjFanin0(pObj), Limit, vNodes)) )
        return 0;
    iFanin = Gia_ObjFaninId1p(p, pObj);
    Vec_IntPush( vNodes, iFanin );
    if ( !Gia_ObjRefDecId(p, iFanin) && (Vec_IntSize(vNodes) > Limit || !Gia_ObjCheckMffc_rec(p, Gia_ObjFanin1(pObj), Limit, vNodes)) )
        return 0;
    if ( !Gia_ObjIsMux(p, pObj) )
        return 1;
    iFanin = Gia_ObjFaninId2p(p, pObj);
    Vec_IntPush( vNodes, iFanin );
    if ( !Gia_ObjRefDecId(p, iFanin) && (Vec_IntSize(vNodes) > Limit || !Gia_ObjCheckMffc_rec(p, Gia_ObjFanin2(p, pObj), Limit, vNodes)) )
        return 0;
    return 1;
}
static inline int Gia_ObjCheckMffc( Gia_Man_t * p, Gia_Obj_t * pRoot, int Limit, Vec_Int_t * vNodes, Vec_Int_t * vLeaves, Vec_Int_t * vInners )
{
    int RetValue, iObj, i;
    Vec_IntClear( vNodes );
    RetValue = Gia_ObjCheckMffc_rec( p, pRoot, Limit, vNodes );
    if ( RetValue )
    {
        Vec_IntClear( vLeaves );
        Vec_IntClear( vInners );
        Vec_IntSort( vNodes, 0 );
        Vec_IntForEachEntry( vNodes, iObj, i )
            if ( Gia_ObjRefNumId(p, iObj) > 0 || Gia_ObjIsCi(Gia_ManObj(p, iObj)) )
            {
                if ( !Vec_IntSize(vLeaves) || Vec_IntEntryLast(vLeaves) != iObj )
                    Vec_IntPush( vLeaves, iObj );
            }
            else
            {
                if ( !Vec_IntSize(vInners) || Vec_IntEntryLast(vInners) != iObj )
                    Vec_IntPush( vInners, iObj );
            }
        Vec_IntPush( vInners, Gia_ObjId(p, pRoot) );
    }
    Vec_IntForEachEntry( vNodes, iObj, i )
        Gia_ObjRefIncId( p, iObj );
    return RetValue;
}
Vec_Wec_t * Gia_ManComputeMffcs( Gia_Man_t * p, int LimitMin, int LimitMax, int SuppMax, int RatioBest )
{
    Gia_Obj_t * pObj;
    Vec_Wec_t * vMffcs;
    Vec_Int_t * vNodes, * vLeaves, * vInners, * vMffc;
    int i, iPivot;
    assert( p->pMuxes );
    vNodes  = Vec_IntAlloc( 2 * LimitMax );
    vLeaves = Vec_IntAlloc( 2 * LimitMax );
    vInners = Vec_IntAlloc( 2 * LimitMax );
    vMffcs  = Vec_WecAlloc( 1000 );
    Gia_ManCreateRefs( p );
    Gia_ManForEachAnd( p, pObj, i )
    {
        if ( !Gia_ObjRefNum(p, pObj) )
            continue;
        if ( !Gia_ObjCheckMffc(p, pObj, LimitMax, vNodes, vLeaves, vInners) )
            continue;
        if ( Vec_IntSize(vInners) < LimitMin )
            continue;
        if ( Vec_IntSize(vLeaves) > SuppMax )
            continue;
        // improve cut
        // collect cut
        vMffc = Vec_WecPushLevel( vMffcs );
        Vec_IntGrow( vMffc, Vec_IntSize(vLeaves) + Vec_IntSize(vInners) + 20 );
        Vec_IntPush( vMffc, i );
        Vec_IntPush( vMffc, Vec_IntSize(vLeaves) );
        Vec_IntPush( vMffc, Vec_IntSize(vInners) );
        Vec_IntAppend( vMffc, vLeaves );
//        Vec_IntAppend( vMffc, vInners );
        // add last entry equal to the ratio
        Vec_IntPush( vMffc, 1000 * Vec_IntSize(vInners) / Vec_IntSize(vLeaves) );
    }
    Vec_IntFree( vNodes );
    Vec_IntFree( vLeaves );
    Vec_IntFree( vInners );
    // sort MFFCs by their inner/leaf ratio
    Vec_WecSortByLastInt( vMffcs, 1 );
    Vec_WecForEachLevel( vMffcs, vMffc, i )
        Vec_IntPop( vMffc );
    // remove those whose ratio is not good
    iPivot = RatioBest * Vec_WecSize(vMffcs) / 100;
    Vec_WecForEachLevelStart( vMffcs, vMffc, i, iPivot )
        Vec_IntErase( vMffc );
    assert( iPivot <= Vec_WecSize(vMffcs) );
    Vec_WecShrink( vMffcs, iPivot );
    return vMffcs;
}

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

  Synopsis    []

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void Gia_ManPrintDivStats( Gia_Man_t * p, Vec_Wec_t * vMffcs, Vec_Wec_t * vPivots ) 
{
    int fVerbose = 0;
    Vec_Int_t * vMffc;
    int i, nDivs, nDivsAll = 0, nDivs0 = 0;
    Vec_WecForEachLevel( vMffcs, vMffc, i )
    {
        nDivs = Vec_IntSize(vMffc) - 3 - Vec_IntEntry(vMffc, 1) - Vec_IntEntry(vMffc, 2);
        nDivs0 += (nDivs == 0);
        nDivsAll += nDivs;
        if ( !fVerbose )
            continue;
        printf( "%6d : ",      Vec_IntEntry(vMffc, 0) );
        printf( "Leaf =%3d  ", Vec_IntEntry(vMffc, 1) );
        printf( "Mffc =%4d  ", Vec_IntEntry(vMffc, 2) );
        printf( "Divs =%4d  ", nDivs );
        printf( "\n" );
    }
    printf( "Collected %d (%.1f %%) MFFCs and %d (%.1f %%) have no divisors (div ave for others is %.2f).\n", 
        Vec_WecSize(vMffcs), 100.0 * Vec_WecSize(vMffcs) / Gia_ManAndNum(p), 
        nDivs0, 100.0 * nDivs0 / Gia_ManAndNum(p), 
        1.0*nDivsAll/Abc_MaxInt(1, Vec_WecSize(vMffcs) - nDivs0) );
    printf( "Using %.2f MB for MFFCs and %.2f MB for pivots.   ", 
        Vec_WecMemory(vMffcs)/(1<<20), Vec_WecMemory(vPivots)/(1<<20) );
}

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

  Synopsis    [Compute divisors and Boolean functions for the nodes.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void Gia_ManAddDivisors( Gia_Man_t * p, Vec_Wec_t * vMffcs )
{
    Vec_Wec_t * vPivots;
    Vec_Int_t * vMffc, * vPivot, * vPivot0, * vPivot1;
    Vec_Int_t * vCommon, * vCommon2, * vMap;
    Gia_Obj_t * pObj;
    int i, k, iObj, iPivot, iMffc;
//abctime clkStart = Abc_Clock();
    // initialize pivots (mapping of nodes into MFFCs whose leaves they are)
    vMap = Vec_IntStartFull( Gia_ManObjNum(p) );
    vPivots = Vec_WecStart( Gia_ManObjNum(p) );
    Vec_WecForEachLevel( vMffcs, vMffc, i )
    {
        assert( Vec_IntSize(vMffc) == 3 + Vec_IntEntry(vMffc, 1) );
        iPivot = Vec_IntEntry( vMffc, 0 );
        Vec_IntWriteEntry( vMap, iPivot, i );
        // iterate through the MFFC leaves
        Vec_IntForEachEntryStart( vMffc, iObj, k, 3 )
        {
            vPivot = Vec_WecEntry( vPivots, iObj );
            if ( Vec_IntSize(vPivot) == 0 )
                Vec_IntGrow(vPivot, 4);
            Vec_IntPush( vPivot, iPivot );            
        }
    }
    Vec_WecForEachLevel( vPivots, vPivot, i )
        Vec_IntSort( vPivot, 0 );
    // create pivots for internal nodes while growing MFFCs
    vCommon = Vec_IntAlloc( 100 );
    vCommon2 = Vec_IntAlloc( 100 );
    Gia_ManForEachAnd( p, pObj, i )
    {
        // find commont pivots
        // the slow down happens because some PIs have very large sets of pivots
        vPivot0 = Vec_WecEntry( vPivots, Gia_ObjFaninId0(pObj, i) );
        vPivot1 = Vec_WecEntry( vPivots, Gia_ObjFaninId1(pObj, i) );
        Vec_IntTwoFindCommon( vPivot0, vPivot1, vCommon );
        if ( Gia_ObjIsMuxId(p, i) )
        {
            vPivot = Vec_WecEntry( vPivots, Gia_ObjFaninId2(p, i) );
            Vec_IntTwoFindCommon( vPivot, vCommon, vCommon2 );
            ABC_SWAP( Vec_Int_t *, vCommon, vCommon2 );
        }
        if ( Vec_IntSize(vCommon) == 0 )
            continue;
        // add new pivots (this trick increased memory used in vPivots)
        vPivot = Vec_WecEntry( vPivots, i );
        Vec_IntTwoMerge2( vPivot, vCommon, vCommon2 );
        ABC_SWAP( Vec_Int_t, *vPivot, *vCommon2 );
        // grow MFFCs
        Vec_IntForEachEntry( vCommon, iObj, k )
        {
            iMffc = Vec_IntEntry( vMap, iObj );
            assert( iMffc != -1 );
            vMffc = Vec_WecEntry( vMffcs, iMffc );
            Vec_IntPush( vMffc, i );
        }
    }
//Abc_PrintTime( 1, "Time", Abc_Clock() - clkStart );
    Vec_IntFree( vCommon );
    Vec_IntFree( vCommon2 );
    Vec_IntFree( vMap );
    Gia_ManPrintDivStats( p, vMffcs, vPivots );
    Vec_WecFree( vPivots );
    // returns the modified array of MFFCs
}
void Gia_ManResubTest( Gia_Man_t * p )
{
    Vec_Wec_t * vMffcs;
    Gia_Man_t * pNew = Gia_ManDupMuxes( p, 2 );
abctime clkStart = Abc_Clock();
    vMffcs = Gia_ManComputeMffcs( pNew, 4, 100, 8, 100 );
    Gia_ManAddDivisors( pNew, vMffcs );
    Vec_WecFree( vMffcs );
Abc_PrintTime( 1, "Time", Abc_Clock() - clkStart );
    Gia_ManStop( pNew );
}


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

  Synopsis    [Perform resubstitution.]

  Description []
               
  SideEffects []

  SeeAlso     []

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

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


ABC_NAMESPACE_IMPL_END