Experiments with support minimization.

1 files changed, 338 insertions, 0 deletions

diff --git a/src/aig/gia/giaSupp.c b/src/aig/gia/giaSupp.c
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+/**CFile****************************************************************
+
+  FileName    [giaSupp.c]
+
+  SystemName  [ABC: Logic synthesis and verification system.]
+
+  PackageName [Scalable AIG package.]
+
+  Synopsis    [Support minimization for AIGs.]
+
+  Author      [Alan Mishchenko]
+  
+  Affiliation [UC Berkeley]
+
+  Date        [Ver. 1.0. Started - June 20, 2005.]
+
+  Revision    [$Id: giaSupp.c,v 1.00 2005/06/20 00:00:00 alanmi Exp $]
+
+***********************************************************************/
+
+#include "gia.h"
+
+#ifdef ABC_USE_CUDD
+#include "bdd/extrab/extraBdd.h"
+#endif
+
+ABC_NAMESPACE_IMPL_START
+
+////////////////////////////////////////////////////////////////////////
+///                        DECLARATIONS                              ///
+////////////////////////////////////////////////////////////////////////
+
+#ifdef ABC_USE_CUDD
+
+struct Gia_ManMin_t_ 
+{
+    // problem formulation
+    Gia_Man_t *     pGia;
+    int             iLits[2];
+    // structural information
+    Vec_Int_t *     vCis[2];
+    Vec_Int_t *     vObjs[2];
+    Vec_Int_t *     vCleared;  
+    // intermediate functions
+    DdManager *     dd;
+    Vec_Ptr_t *     vFuncs;
+    Vec_Int_t *     vSupp;
+};
+
+////////////////////////////////////////////////////////////////////////
+///                     FUNCTION DEFINITIONS                         ///
+////////////////////////////////////////////////////////////////////////
+
+/**Function*************************************************************
+
+  Synopsis    [Create/delete the data representation manager.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+Gia_ManMin_t * Gia_ManSuppStart( Gia_Man_t * pGia )
+{
+    Gia_ManMin_t * p;
+    p = ABC_CALLOC( Gia_ManMin_t, 1 );
+    p->pGia     = pGia;
+    p->vCis[0]  = Vec_IntAlloc( 512 );
+    p->vCis[1]  = Vec_IntAlloc( 512 );
+    p->vObjs[0] = Vec_IntAlloc( 512 );
+    p->vObjs[1] = Vec_IntAlloc( 512 );
+    p->vCleared = Vec_IntAlloc( 512 );
+    p->dd = Cudd_Init( 0, 0, CUDD_UNIQUE_SLOTS, CUDD_CACHE_SLOTS, 0 );
+//    Cudd_AutodynEnable( p->dd,  CUDD_REORDER_SYMM_SIFT );
+    Cudd_AutodynDisable( p->dd );
+    p->vFuncs   = Vec_PtrAlloc( 10000 );
+    p->vSupp    = Vec_IntAlloc( 10000 );
+    return p;
+}
+void Gia_ManSuppStop( Gia_ManMin_t * p )
+{
+    Vec_IntFreeP( &p->vCis[0] );
+    Vec_IntFreeP( &p->vCis[1] );
+    Vec_IntFreeP( &p->vObjs[0] );
+    Vec_IntFreeP( &p->vObjs[1] );
+    Vec_IntFreeP( &p->vCleared );
+    Vec_PtrFreeP( &p->vFuncs );
+    Vec_IntFreeP( &p->vSupp );
+    printf( "Refs = %d. \n", Cudd_CheckZeroRef( p->dd ) );
+    Cudd_Quit( p->dd );
+    ABC_FREE( p );
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Compute variables, which are not in the support.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int Gia_ManFindRemoved( Gia_ManMin_t * p ) 
+{
+    extern void ddSupportStep2( DdNode * f, int * support );
+    extern void ddClearFlag2( DdNode * f );
+
+    //int fVerbose = 1;
+    int nBddLimit = 100000;
+    int nPart0 = Vec_IntSize(p->vCis[0]);
+    int n, i, iObj, nVars = 0;
+    DdNode * bFunc0, * bFunc1, * bFunc;
+    Vec_PtrFillExtra( p->vFuncs, Gia_ManObjNum(p->pGia), NULL );
+    // assign variables
+    for ( n = 0; n < 2; n++ )
+        Vec_IntForEachEntry( p->vCis[n], iObj, i )
+            Vec_PtrWriteEntry( p->vFuncs, iObj, Cudd_bddIthVar(p->dd, nVars++) );
+    // create nodes
+    for ( n = 0; n < 2; n++ )
+        Vec_IntForEachEntry( p->vObjs[n], iObj, i )
+        {
+            Gia_Obj_t * pObj = Gia_ManObj( p->pGia, iObj );
+            bFunc0 = Cudd_NotCond( (DdNode *)Vec_PtrEntry(p->vFuncs, Gia_ObjFaninId0(pObj, iObj)), Gia_ObjFaninC0(pObj) );
+            bFunc1 = Cudd_NotCond( (DdNode *)Vec_PtrEntry(p->vFuncs, Gia_ObjFaninId1(pObj, iObj)), Gia_ObjFaninC1(pObj) );
+            bFunc  = Cudd_bddAndLimit( p->dd, bFunc0, bFunc1, nBddLimit );  
+            assert( bFunc != NULL );
+            Cudd_Ref( bFunc );
+            Vec_PtrWriteEntry( p->vFuncs, iObj, bFunc );
+        }
+    // create new node
+    bFunc0 = Cudd_NotCond( (DdNode *)Vec_PtrEntry(p->vFuncs, Abc_Lit2Var(p->iLits[0])), Abc_LitIsCompl(p->iLits[0]) );
+    bFunc1 = Cudd_NotCond( (DdNode *)Vec_PtrEntry(p->vFuncs, Abc_Lit2Var(p->iLits[1])), Abc_LitIsCompl(p->iLits[1]) );
+    bFunc  = Cudd_bddAndLimit( p->dd, bFunc0, bFunc1, nBddLimit );  
+    assert( bFunc != NULL );
+    Cudd_Ref( bFunc );
+    //if ( fVerbose ) Extra_bddPrint( p->dd, bFunc ), printf( "\n" );
+    // collect support
+    Vec_IntFill( p->vSupp, nVars, 0 );
+    ddSupportStep2( Cudd_Regular(bFunc), Vec_IntArray(p->vSupp) );
+    ddClearFlag2( Cudd_Regular(bFunc) );
+    // find variables not present in the support
+    Vec_IntClear( p->vCleared );
+    for ( i = 0; i < nVars; i++ )
+        if ( Vec_IntEntry(p->vSupp, i) == 0 )
+            Vec_IntPush( p->vCleared, i < nPart0 ? Vec_IntEntry(p->vCis[0], i) : Vec_IntEntry(p->vCis[1], i-nPart0) );
+    //printf( "%d(%d)%d  ", Cudd_SupportSize(p->dd, bFunc), Vec_IntSize(p->vCleared), Cudd_DagSize(bFunc) );
+    // deref results
+    Cudd_RecursiveDeref( p->dd, bFunc );
+    for ( n = 0; n < 2; n++ )
+        Vec_IntForEachEntry( p->vObjs[n], iObj, i )
+            Cudd_RecursiveDeref( p->dd, (DdNode *)Vec_PtrEntry(p->vFuncs, iObj) );
+    //Vec_IntPrint( p->vCleared );
+    return Vec_IntSize(p->vCleared);
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Compute variables, which are not in the support.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int Gia_ManRebuildOne( Gia_ManMin_t * p, int n ) 
+{
+    int i, iObj, iGiaLitNew = -1;
+    Vec_Int_t * vTempIns = p->vCis[n]; 
+    Vec_Int_t * vTempNds = p->vObjs[n];
+    Vec_Int_t * vCopies  = &p->pGia->vCopies;
+    Vec_IntFillExtra( vCopies, Gia_ManObjNum(p->pGia), -1 );
+    assert( p->iLits[n] >= 2 );
+    // process inputs
+    Vec_IntForEachEntry( vTempIns, iObj, i )
+        Vec_IntWriteEntry( vCopies, iObj, Abc_Var2Lit(iObj, 0) );
+    // process constants
+    assert( Vec_IntSize(p->vCleared) > 0 );
+    Vec_IntForEachEntry( p->vCleared, iObj, i )
+        Vec_IntWriteEntry( vCopies, iObj, 0 );
+    if ( Vec_IntSize(vTempNds) == 0 )
+        iGiaLitNew = Vec_IntEntry( vCopies, Abc_Lit2Var(p->iLits[n]) );
+    else
+    {
+        Vec_IntForEachEntry( vTempNds, iObj, i )
+        {
+            Gia_Obj_t * pObj = Gia_ManObj( p->pGia, iObj );
+            int iGiaLit0 = Vec_IntEntry( vCopies, Gia_ObjFaninId0p(p->pGia, pObj) );
+            int iGiaLit1 = Vec_IntEntry( vCopies, Gia_ObjFaninId1p(p->pGia, pObj) );
+            iGiaLit0   = Abc_LitNotCond( iGiaLit0, Gia_ObjFaninC0(pObj) );
+            iGiaLit1   = Abc_LitNotCond( iGiaLit1, Gia_ObjFaninC1(pObj) );
+            iGiaLitNew = Gia_ManHashAnd( p->pGia, iGiaLit0, iGiaLit1 );
+            Vec_IntWriteEntry( vCopies, iObj, iGiaLitNew );
+        }
+        assert( Abc_Lit2Var(p->iLits[n]) == iObj );
+    }
+    return Abc_LitNotCond( iGiaLitNew, Abc_LitIsCompl(p->iLits[n]) );
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Collect nodes.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline int Gia_ManGatherSupp_rec( Gia_Man_t * p, int iObj, Vec_Int_t * vCis, Vec_Int_t * vObjs )
+{
+    int Val0, Val1;
+    Gia_Obj_t * pObj;
+    if ( Gia_ObjIsTravIdPreviousId(p, iObj) )
+        return 1;
+    if ( Gia_ObjIsTravIdCurrentId(p, iObj) )
+        return 0;
+    Gia_ObjSetTravIdCurrentId(p, iObj);
+    pObj = Gia_ManObj( p, iObj );
+    if ( Gia_ObjIsCi(pObj) )
+    {
+        Vec_IntPush( vCis, iObj );
+        return 0;
+    }
+    assert( Gia_ObjIsAnd(pObj) );
+    Val0 = Gia_ManGatherSupp_rec( p, Gia_ObjFaninId0(pObj, iObj), vCis, vObjs );
+    Val1 = Gia_ManGatherSupp_rec( p, Gia_ObjFaninId1(pObj, iObj), vCis, vObjs );
+    Vec_IntPush( vObjs, iObj );
+    return Val0 || Val1;
+}
+int Gia_ManGatherSupp( Gia_ManMin_t * p )
+{
+    int n, Overlap = 0;
+    Gia_ManIncrementTravId( p->pGia );
+    for ( n = 0; n < 2; n++ )
+    {
+        Vec_IntClear( p->vCis[n] );
+        Vec_IntClear( p->vObjs[n] );
+        Gia_ManIncrementTravId( p->pGia );
+        Overlap = Gia_ManGatherSupp_rec( p->pGia, Abc_Lit2Var(p->iLits[n]), p->vCis[n], p->vObjs[n] );
+        assert( n || !Overlap );
+    }
+    return Overlap;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Takes a literal and returns a support-minized literal.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int Gia_ManSupportAnd( Gia_ManMin_t * p, int iLit0, int iLit1 )
+{
+    int iLitNew0, iLitNew1;
+    p->iLits[0] = iLit0;
+    p->iLits[1] = iLit1;
+    if ( iLit0 < 2 || iLit1 < 2 || !Gia_ManGatherSupp(p) || !Gia_ManFindRemoved(p) )
+        return Gia_ManHashAnd( p->pGia, iLit0, iLit1 );
+    iLitNew0 = Gia_ManRebuildOne( p, 0 );
+    iLitNew1 = Gia_ManRebuildOne( p, 1 );
+    return Gia_ManHashAnd( p->pGia, iLitNew0, iLitNew1 );
+}
+
+
+#else
+
+Gia_ManMin_t * Gia_ManSuppStart( Gia_Man_t * pGia )              { return NULL; }
+int Gia_ManSupportAnd( Gia_ManMin_t * p, int iLit0, int iLit1 )  { return 0;    }
+void Gia_ManSuppStop( Gia_ManMin_t * p )                         {}
+
+#endif
+
+
+/**Function*************************************************************
+
+  Synopsis    [Testbench.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+Gia_Man_t * Gia_ManSupportAndTest( Gia_Man_t * pGia )
+{
+    Gia_ManMin_t * pMan;
+    Gia_Man_t * pNew, * pTemp;
+    Gia_Obj_t * pObj;
+    int i;
+    Gia_ManFillValue( pGia );
+    pNew = Gia_ManStart( Gia_ManObjNum(pGia) );
+    pNew->pName = Abc_UtilStrsav( pGia->pName );
+    pNew->pSpec = Abc_UtilStrsav( pGia->pSpec );
+    Gia_ManHashAlloc( pNew );
+    Gia_ManConst0(pGia)->Value = 0;
+    pMan = Gia_ManSuppStart( pNew );
+    Gia_ManForEachObj1( pGia, pObj, i )
+    {
+        if ( Gia_ObjIsAnd(pObj) )
+        {
+//            pObj->Value = Gia_ManAppendAnd( pNew, Gia_ObjFanin0Copy(pObj), Gia_ObjFanin1Copy(pObj) );
+            pObj->Value = Gia_ManSupportAnd( pMan, Gia_ObjFanin0Copy(pObj), Gia_ObjFanin1Copy(pObj) );
+        }
+        else if ( Gia_ObjIsCi(pObj) )
+            pObj->Value = Gia_ManAppendCi( pNew );
+        else if ( Gia_ObjIsCo(pObj) )
+            pObj->Value = Gia_ManAppendCo( pNew, Gia_ObjFanin0Copy(pObj) );
+        else assert( 0 );
+
+        if ( i % 10000 == 0 )
+            printf( "%d\n", i );
+    }
+    Gia_ManSuppStop( pMan );
+    Gia_ManSetRegNum( pNew, Gia_ManRegNum(pGia) );
+    pNew = Gia_ManCleanup( pTemp = pNew );
+    Gia_ManStop( pTemp );
+    return pNew;
+}
+
+////////////////////////////////////////////////////////////////////////
+///                       END OF FILE                                ///
+////////////////////////////////////////////////////////////////////////
+
+
+ABC_NAMESPACE_IMPL_END
+