cuddZddFuncs.c File Reference

#include "misc/util/util_hack.h"
#include "cuddInt.h"

Go to the source code of this file.

Functions
DdNode *	Cudd_zddProduct (DdManager *dd, DdNode *f, DdNode *g)
DdNode *	Cudd_zddUnateProduct (DdManager *dd, DdNode *f, DdNode *g)
DdNode *	Cudd_zddWeakDiv (DdManager *dd, DdNode *f, DdNode *g)
DdNode *	Cudd_zddDivide (DdManager *dd, DdNode *f, DdNode *g)
DdNode *	Cudd_zddWeakDivF (DdManager *dd, DdNode *f, DdNode *g)
DdNode *	Cudd_zddDivideF (DdManager *dd, DdNode *f, DdNode *g)
DdNode *	Cudd_zddComplement (DdManager *dd, DdNode *node)
DdNode *	cuddZddProduct (DdManager *dd, DdNode *f, DdNode *g)
DdNode *	cuddZddUnateProduct (DdManager *dd, DdNode *f, DdNode *g)
DdNode *	cuddZddWeakDiv (DdManager *dd, DdNode *f, DdNode *g)
DdNode *	cuddZddWeakDivF (DdManager *dd, DdNode *f, DdNode *g)
DdNode *	cuddZddDivide (DdManager *dd, DdNode *f, DdNode *g)
DdNode *	cuddZddDivideF (DdManager *dd, DdNode *f, DdNode *g)
int	cuddZddGetCofactors3 (DdManager *dd, DdNode *f, int v, DdNode **f1, DdNode **f0, DdNode **fd)
int	cuddZddGetCofactors2 (DdManager *dd, DdNode *f, int v, DdNode **f1, DdNode **f0)
DdNode *	cuddZddComplement (DdManager *dd, DdNode *node)
int	cuddZddGetPosVarIndex (DdManager *dd, int index)
int	cuddZddGetNegVarIndex (DdManager *dd, int index)
int	cuddZddGetPosVarLevel (DdManager *dd, int index)
int	cuddZddGetNegVarLevel (DdManager *dd, int index)

Variables
static ABC_NAMESPACE_IMPL_START char rcsid[]	DD_UNUSED = "$Id: cuddZddFuncs.c,v 1.16 2008/04/25 07:39:33 fabio Exp $"

Function Documentation

DdNode* Cudd_zddComplement	(	DdManager *	dd,
		DdNode *	node
	)

Function********************************************************************

Synopsis [Computes a complement cover for a ZDD node.]

Description [Computes a complement cover for a ZDD node. For lack of a better method, we first extract the function BDD from the ZDD cover, then make the complement of the ZDD cover from the complement of the BDD node by using ISOP. Returns a pointer to the resulting cover if successful; NULL otherwise. The result depends on current variable order.]

SideEffects [The result depends on current variable order.]

SeeAlso []

Definition at line 332 of file cuddZddFuncs.c.

{
    DdNode      *b, *isop, *zdd_I;

    /* Check cache */
    zdd_I = cuddCacheLookup1Zdd(dd, cuddZddComplement, node);
    if (zdd_I)
        return(zdd_I);

    b = Cudd_MakeBddFromZddCover(dd, node);
    if (!b)
        return(NULL);
    Cudd_Ref(b);
    isop = Cudd_zddIsop(dd, Cudd_Not(b), Cudd_Not(b), &zdd_I);
    if (!isop) {
        Cudd_RecursiveDeref(dd, b);
        return(NULL);
    }
    Cudd_Ref(isop);
    Cudd_Ref(zdd_I);
    Cudd_RecursiveDeref(dd, b);
    Cudd_RecursiveDeref(dd, isop);

    cuddCacheInsert1(dd, cuddZddComplement, node, zdd_I);
    Cudd_Deref(zdd_I);
    return(zdd_I);
} /* end of Cudd_zddComplement */

DdNode* Cudd_zddDivide	(	DdManager *	dd,
		DdNode *	f,
		DdNode *	g
	)

Function********************************************************************

Synopsis [Computes the quotient of two unate covers.]

Description [Computes the quotient of two unate covers represented by ZDDs. Unate covers use one ZDD variable for each BDD variable. Returns a pointer to the resulting ZDD if successful; NULL otherwise.]

SideEffects [None]

SeeAlso [Cudd_zddWeakDiv]

Definition at line 241 of file cuddZddFuncs.c.

{
    DdNode      *res;

    do {
        dd->reordered = 0;
        res = cuddZddDivide(dd, f, g);
    } while (dd->reordered == 1);
    return(res);

} /* end of Cudd_zddDivide */

DdNode* Cudd_zddDivideF	(	DdManager *	dd,
		DdNode *	f,
		DdNode *	g
	)

Function********************************************************************

Synopsis [Modified version of Cudd_zddDivide.]

Description [Modified version of Cudd_zddDivide. This function may disappear in future releases.]

SideEffects [None]

SeeAlso []

Definition at line 299 of file cuddZddFuncs.c.

{
    DdNode      *res;

    do {
        dd->reordered = 0;
        res = cuddZddDivideF(dd, f, g);
    } while (dd->reordered == 1);
    return(res);

} /* end of Cudd_zddDivideF */

DdNode* Cudd_zddProduct	(	DdManager *	dd,
		DdNode *	f,
		DdNode *	g
	)

AutomaticStart AutomaticEnd Function********************************************************************

Synopsis [Computes the product of two covers represented by ZDDs.]

Description [Computes the product of two covers represented by ZDDs. The result is also a ZDD. Returns a pointer to the result if successful; NULL otherwise. The covers on which Cudd_zddProduct operates use two ZDD variables for each function variable (one ZDD variable for each literal of the variable). Those two ZDD variables should be adjacent in the order.]

SideEffects [None]

SeeAlso [Cudd_zddUnateProduct]

Definition at line 145 of file cuddZddFuncs.c.

{
    DdNode      *res;

    do {
        dd->reordered = 0;
        res = cuddZddProduct(dd, f, g);
    } while (dd->reordered == 1);
    return(res);

} /* end of Cudd_zddProduct */

DdNode* Cudd_zddUnateProduct	(	DdManager *	dd,
		DdNode *	f,
		DdNode *	g
	)

Function********************************************************************

Synopsis [Computes the product of two unate covers.]

Description [Computes the product of two unate covers represented as ZDDs. Unate covers use one ZDD variable for each BDD variable. Returns a pointer to the result if successful; NULL otherwise.]

SideEffects [None]

SeeAlso [Cudd_zddProduct]

Definition at line 176 of file cuddZddFuncs.c.

{
    DdNode      *res;

    do {
        dd->reordered = 0;
        res = cuddZddUnateProduct(dd, f, g);
    } while (dd->reordered == 1);
    return(res);

} /* end of Cudd_zddUnateProduct */

DdNode* Cudd_zddWeakDiv	(	DdManager *	dd,
		DdNode *	f,
		DdNode *	g
	)

Function********************************************************************

Synopsis [Applies weak division to two covers.]

Description [Applies weak division to two ZDDs representing two covers. Returns a pointer to the ZDD representing the result if successful; NULL otherwise. The result of weak division depends on the variable order. The covers on which Cudd_zddWeakDiv operates use two ZDD variables for each function variable (one ZDD variable for each literal of the variable). Those two ZDD variables should be adjacent in the order.]

SideEffects [None]

SeeAlso [Cudd_zddDivide]

Definition at line 210 of file cuddZddFuncs.c.

{
    DdNode      *res;

    do {
        dd->reordered = 0;
        res = cuddZddWeakDiv(dd, f, g);
    } while (dd->reordered == 1);
    return(res);

} /* end of Cudd_zddWeakDiv */

DdNode* Cudd_zddWeakDivF	(	DdManager *	dd,
		DdNode *	f,
		DdNode *	g
	)

Function********************************************************************

Synopsis [Modified version of Cudd_zddWeakDiv.]

Description [Modified version of Cudd_zddWeakDiv. This function may disappear in future releases.]

SideEffects [None]

SeeAlso [Cudd_zddWeakDiv]

Definition at line 270 of file cuddZddFuncs.c.

{
    DdNode      *res;

    do {
        dd->reordered = 0;
        res = cuddZddWeakDivF(dd, f, g);
    } while (dd->reordered == 1);
    return(res);

} /* end of Cudd_zddWeakDivF */

DdNode* cuddZddComplement	(	DdManager *	dd,
		DdNode *	node
	)

Function********************************************************************

Synopsis [Computes a complement of a ZDD node.]

Description [Computes the complement of a ZDD node. So far, since we couldn't find a direct way to get the complement of a ZDD cover, we first convert a ZDD cover to a BDD, then make the complement of the ZDD cover from the complement of the BDD node by using ISOP.]

SideEffects [The result depends on current variable order.]

SeeAlso []

Definition at line 1522 of file cuddZddFuncs.c.

{
    DdNode      *b, *isop, *zdd_I;

    /* Check cache */
    zdd_I = cuddCacheLookup1Zdd(dd, cuddZddComplement, node);
    if (zdd_I)
        return(zdd_I);

    b = cuddMakeBddFromZddCover(dd, node);
    if (!b)
        return(NULL);
    cuddRef(b);
    isop = cuddZddIsop(dd, Cudd_Not(b), Cudd_Not(b), &zdd_I);
    if (!isop) {
        Cudd_RecursiveDeref(dd, b);
        return(NULL);
    }
    cuddRef(isop);
    cuddRef(zdd_I);
    Cudd_RecursiveDeref(dd, b);
    Cudd_RecursiveDeref(dd, isop);

    cuddCacheInsert1(dd, cuddZddComplement, node, zdd_I);
    cuddDeref(zdd_I);
    return(zdd_I);
} /* end of cuddZddComplement */

DdNode* cuddZddDivide	(	DdManager *	dd,
		DdNode *	f,
		DdNode *	g
	)

Function********************************************************************

Synopsis [Performs the recursive step of Cudd_zddDivide.]

Description []

SideEffects [None]

SeeAlso [Cudd_zddDivide]

Definition at line 1159 of file cuddZddFuncs.c.

{
    int         v;
    DdNode      *one = DD_ONE(dd);
    DdNode      *zero = DD_ZERO(dd);
    DdNode      *f0, *f1, *g0, *g1;
    DdNode      *q, *r, *tmp;
    int         flag;

    statLine(dd);
    if (g == one)
        return(f);
    if (f == zero || f == one)
        return(zero);
    if (f == g)
        return(one);

    /* Check cache. */
    r = cuddCacheLookup2Zdd(dd, cuddZddDivide, f, g);
    if (r)
        return(r);

    v = g->index;

    flag = cuddZddGetCofactors2(dd, f, v, &f1, &f0);
    if (flag == 1)
        return(NULL);
    Cudd_Ref(f1);
    Cudd_Ref(f0);
    flag = cuddZddGetCofactors2(dd, g, v, &g1, &g0);    /* g1 != zero */
    if (flag == 1) {
        Cudd_RecursiveDerefZdd(dd, f1);
        Cudd_RecursiveDerefZdd(dd, f0);
        return(NULL);
    }
    Cudd_Ref(g1);
    Cudd_Ref(g0);

    r = cuddZddDivide(dd, f1, g1);
    if (r == NULL) {
        Cudd_RecursiveDerefZdd(dd, f1);
        Cudd_RecursiveDerefZdd(dd, f0);
        Cudd_RecursiveDerefZdd(dd, g1);
        Cudd_RecursiveDerefZdd(dd, g0);
        return(NULL);
    }
    Cudd_Ref(r);

    if (r != zero && g0 != zero) {
        tmp = r;
        q = cuddZddDivide(dd, f0, g0);
        if (q == NULL) {
            Cudd_RecursiveDerefZdd(dd, f1);
            Cudd_RecursiveDerefZdd(dd, f0);
            Cudd_RecursiveDerefZdd(dd, g1);
            Cudd_RecursiveDerefZdd(dd, g0);
            return(NULL);
        }
        Cudd_Ref(q);
        r = cuddZddIntersect(dd, r, q);
        if (r == NULL) {
            Cudd_RecursiveDerefZdd(dd, f1);
            Cudd_RecursiveDerefZdd(dd, f0);
            Cudd_RecursiveDerefZdd(dd, g1);
            Cudd_RecursiveDerefZdd(dd, g0);
            Cudd_RecursiveDerefZdd(dd, q);
            return(NULL);
        }
        Cudd_Ref(r);
        Cudd_RecursiveDerefZdd(dd, q);
        Cudd_RecursiveDerefZdd(dd, tmp);
    }

    Cudd_RecursiveDerefZdd(dd, f1);
    Cudd_RecursiveDerefZdd(dd, f0);
    Cudd_RecursiveDerefZdd(dd, g1);
    Cudd_RecursiveDerefZdd(dd, g0);
    
    cuddCacheInsert2(dd, cuddZddDivide, f, g, r);
    Cudd_Deref(r);
    return(r);

} /* end of cuddZddDivide */

DdNode* cuddZddDivideF	(	DdManager *	dd,
		DdNode *	f,
		DdNode *	g
	)

Function********************************************************************

Synopsis [Performs the recursive step of Cudd_zddDivideF.]

Description []

SideEffects [None]

SeeAlso [Cudd_zddDivideF]

Definition at line 1259 of file cuddZddFuncs.c.

{
    int         v;
    DdNode      *one = DD_ONE(dd);
    DdNode      *zero = DD_ZERO(dd);
    DdNode      *f0, *f1, *g0, *g1;
    DdNode      *q, *r, *tmp;
    int         flag;

    statLine(dd);
    if (g == one)
        return(f);
    if (f == zero || f == one)
        return(zero);
    if (f == g)
        return(one);

    /* Check cache. */
    r = cuddCacheLookup2Zdd(dd, cuddZddDivideF, f, g);
    if (r)
        return(r);

    v = g->index;

    flag = cuddZddGetCofactors2(dd, f, v, &f1, &f0);
    if (flag == 1)
        return(NULL);
    Cudd_Ref(f1);
    Cudd_Ref(f0);
    flag = cuddZddGetCofactors2(dd, g, v, &g1, &g0);    /* g1 != zero */
    if (flag == 1) {
        Cudd_RecursiveDerefZdd(dd, f1);
        Cudd_RecursiveDerefZdd(dd, f0);
        return(NULL);
    }
    Cudd_Ref(g1);
    Cudd_Ref(g0);

    r = cuddZddDivideF(dd, f1, g1);
    if (r == NULL) {
        Cudd_RecursiveDerefZdd(dd, f1);
        Cudd_RecursiveDerefZdd(dd, f0);
        Cudd_RecursiveDerefZdd(dd, g1);
        Cudd_RecursiveDerefZdd(dd, g0);
        return(NULL);
    }
    Cudd_Ref(r);

    if (r != zero && g0 != zero) {
        tmp = r;
        q = cuddZddDivideF(dd, f0, g0);
        if (q == NULL) {
            Cudd_RecursiveDerefZdd(dd, f1);
            Cudd_RecursiveDerefZdd(dd, f0);
            Cudd_RecursiveDerefZdd(dd, g1);
            Cudd_RecursiveDerefZdd(dd, g0);
            return(NULL);
        }
        Cudd_Ref(q);
        r = cuddZddIntersect(dd, r, q);
        if (r == NULL) {
            Cudd_RecursiveDerefZdd(dd, f1);
            Cudd_RecursiveDerefZdd(dd, f0);
            Cudd_RecursiveDerefZdd(dd, g1);
            Cudd_RecursiveDerefZdd(dd, g0);
            Cudd_RecursiveDerefZdd(dd, q);
            return(NULL);
        }
        Cudd_Ref(r);
        Cudd_RecursiveDerefZdd(dd, q);
        Cudd_RecursiveDerefZdd(dd, tmp);
    }

    Cudd_RecursiveDerefZdd(dd, f1);
    Cudd_RecursiveDerefZdd(dd, f0);
    Cudd_RecursiveDerefZdd(dd, g1);
    Cudd_RecursiveDerefZdd(dd, g0);
    
    cuddCacheInsert2(dd, cuddZddDivideF, f, g, r);
    Cudd_Deref(r);
    return(r);

} /* end of cuddZddDivideF */

int cuddZddGetCofactors2	(	DdManager *	dd,
		DdNode *	f,
		int	v,
		DdNode **	f1,
		DdNode **	f0
	)

Function********************************************************************

Synopsis [Computes the two-way decomposition of f w.r.t. v.]

Description []

SideEffects [The results are returned in f1 and f0.]

SeeAlso [cuddZddGetCofactors3]

Definition at line 1487 of file cuddZddFuncs.c.

{
    *f1 = cuddZddSubset1(dd, f, v);
    if (*f1 == NULL)
        return(1);
    *f0 = cuddZddSubset0(dd, f, v);
    if (*f0 == NULL) {
        Cudd_RecursiveDerefZdd(dd, *f1);
        return(1);
    }
    return(0);

} /* end of cuddZddGetCofactors2 */

int cuddZddGetCofactors3	(	DdManager *	dd,
		DdNode *	f,
		int	v,
		DdNode **	f1,
		DdNode **	f0,
		DdNode **	fd
	)

Function********************************************************************

Synopsis [Computes the three-way decomposition of f w.r.t. v.]

Description [Computes the three-way decomposition of function f (represented by a ZDD) wit respect to variable v. Returns 0 if successful; 1 otherwise.]

SideEffects [The results are returned in f1, f0, and fd.]

SeeAlso [cuddZddGetCofactors2]

Definition at line 1360 of file cuddZddFuncs.c.

{
    DdNode      *pc, *nc;
    DdNode      *zero = DD_ZERO(dd);
    int         top, hv, ht, pv, nv;
    int         level;

    top = dd->permZ[f->index];
    level = dd->permZ[v];
    hv = level >> 1;
    ht = top >> 1;

    if (hv < ht) {
        *f1 = zero;
        *f0 = zero;
        *fd = f;
    }
    else {
        pv = cuddZddGetPosVarIndex(dd, v);
        nv = cuddZddGetNegVarIndex(dd, v);

        /* not to create intermediate ZDD node */
        if (cuddZddGetPosVarLevel(dd, v) < cuddZddGetNegVarLevel(dd, v)) {
            pc = cuddZddSubset1(dd, f, pv);
            if (pc == NULL)
                return(1);
            Cudd_Ref(pc);
            nc = cuddZddSubset0(dd, f, pv);
            if (nc == NULL) {
                Cudd_RecursiveDerefZdd(dd, pc);
                return(1);
            }
            Cudd_Ref(nc);

            *f1 = cuddZddSubset0(dd, pc, nv);
            if (*f1 == NULL) {
                Cudd_RecursiveDerefZdd(dd, pc);
                Cudd_RecursiveDerefZdd(dd, nc);
                return(1);
            }
            Cudd_Ref(*f1);
            *f0 = cuddZddSubset1(dd, nc, nv);
            if (*f0 == NULL) {
                Cudd_RecursiveDerefZdd(dd, pc);
                Cudd_RecursiveDerefZdd(dd, nc);
                Cudd_RecursiveDerefZdd(dd, *f1);
                return(1);
            }
            Cudd_Ref(*f0);

            *fd = cuddZddSubset0(dd, nc, nv);
            if (*fd == NULL) {
                Cudd_RecursiveDerefZdd(dd, pc);
                Cudd_RecursiveDerefZdd(dd, nc);
                Cudd_RecursiveDerefZdd(dd, *f1);
                Cudd_RecursiveDerefZdd(dd, *f0);
                return(1);
            }
            Cudd_Ref(*fd);
        } else {
            pc = cuddZddSubset1(dd, f, nv);
            if (pc == NULL)
                return(1);
            Cudd_Ref(pc);
            nc = cuddZddSubset0(dd, f, nv);
            if (nc == NULL) {
                Cudd_RecursiveDerefZdd(dd, pc);
                return(1);
            }
            Cudd_Ref(nc);

            *f0 = cuddZddSubset0(dd, pc, pv);
            if (*f0 == NULL) {
                Cudd_RecursiveDerefZdd(dd, pc);
                Cudd_RecursiveDerefZdd(dd, nc);
                return(1);
            }
            Cudd_Ref(*f0);
            *f1 = cuddZddSubset1(dd, nc, pv);
            if (*f1 == NULL) {
                Cudd_RecursiveDerefZdd(dd, pc);
                Cudd_RecursiveDerefZdd(dd, nc);
                Cudd_RecursiveDerefZdd(dd, *f0);
                return(1);
            }
            Cudd_Ref(*f1);

            *fd = cuddZddSubset0(dd, nc, pv);
            if (*fd == NULL) {
                Cudd_RecursiveDerefZdd(dd, pc);
                Cudd_RecursiveDerefZdd(dd, nc);
                Cudd_RecursiveDerefZdd(dd, *f1);
                Cudd_RecursiveDerefZdd(dd, *f0);
                return(1);
            }
            Cudd_Ref(*fd);
        }

        Cudd_RecursiveDerefZdd(dd, pc);
        Cudd_RecursiveDerefZdd(dd, nc);
        Cudd_Deref(*f1);
        Cudd_Deref(*f0);
        Cudd_Deref(*fd);
    }
    return(0);

} /* end of cuddZddGetCofactors3 */

int cuddZddGetNegVarIndex	(	DdManager *	dd,
		int	index
	)

Function********************************************************************

Synopsis [Returns the index of negative ZDD variable.]

Description [Returns the index of negative ZDD variable.]

SideEffects []

SeeAlso []

Definition at line 1586 of file cuddZddFuncs.c.

{
    int nv = index | 0x1;
    return(nv);
} /* end of cuddZddGetPosVarIndex */

int cuddZddGetNegVarLevel	(	DdManager *	dd,
		int	index
	)

Function********************************************************************

Synopsis [Returns the level of negative ZDD variable.]

Description [Returns the level of negative ZDD variable.]

SideEffects []

SeeAlso []

Definition at line 1628 of file cuddZddFuncs.c.

{
    int nv = cuddZddGetNegVarIndex(dd, index);
    return(dd->permZ[nv]);
} /* end of cuddZddGetNegVarLevel */

int cuddZddGetPosVarIndex	(	DdManager *	dd,
		int	index
	)

Function********************************************************************

Synopsis [Returns the index of positive ZDD variable.]

Description [Returns the index of positive ZDD variable.]

SideEffects []

SeeAlso []

Definition at line 1565 of file cuddZddFuncs.c.

{
    int pv = (index >> 1) << 1;
    return(pv);
} /* end of cuddZddGetPosVarIndex */

int cuddZddGetPosVarLevel	(	DdManager *	dd,
		int	index
	)

Function********************************************************************

Synopsis [Returns the level of positive ZDD variable.]

Description [Returns the level of positive ZDD variable.]

SideEffects []

SeeAlso []

Definition at line 1607 of file cuddZddFuncs.c.

{
    int pv = cuddZddGetPosVarIndex(dd, index);
    return(dd->permZ[pv]);
} /* end of cuddZddGetPosVarLevel */

DdNode* cuddZddProduct	(	DdManager *	dd,
		DdNode *	f,
		DdNode *	g
	)

Function********************************************************************

Synopsis [Performs the recursive step of Cudd_zddProduct.]

Description []

SideEffects [None]

SeeAlso [Cudd_zddProduct]

Definition at line 380 of file cuddZddFuncs.c.

{
    int         v, top_f, top_g;
    DdNode      *tmp, *term1, *term2, *term3;
    DdNode      *f0, *f1, *fd, *g0, *g1, *gd;
    DdNode      *R0, *R1, *Rd, *N0, *N1;
    DdNode      *r;
    DdNode      *one = DD_ONE(dd);
    DdNode      *zero = DD_ZERO(dd);
    int         flag;
    int         pv, nv;

    statLine(dd);
    if (f == zero || g == zero)
        return(zero);
    if (f == one)
        return(g);
    if (g == one)
        return(f);

    top_f = dd->permZ[f->index];
    top_g = dd->permZ[g->index];

    if (top_f > top_g)
        return(cuddZddProduct(dd, g, f));

    /* Check cache */
    r = cuddCacheLookup2Zdd(dd, cuddZddProduct, f, g);
    if (r)
        return(r);

    v = f->index;       /* either yi or zi */
    flag = cuddZddGetCofactors3(dd, f, v, &f1, &f0, &fd);
    if (flag == 1)
        return(NULL);
    Cudd_Ref(f1);
    Cudd_Ref(f0);
    Cudd_Ref(fd);
    flag = cuddZddGetCofactors3(dd, g, v, &g1, &g0, &gd);
    if (flag == 1) {
        Cudd_RecursiveDerefZdd(dd, f1);
        Cudd_RecursiveDerefZdd(dd, f0);
        Cudd_RecursiveDerefZdd(dd, fd);
        return(NULL);
    }
    Cudd_Ref(g1);
    Cudd_Ref(g0);
    Cudd_Ref(gd);
    pv = cuddZddGetPosVarIndex(dd, v);
    nv = cuddZddGetNegVarIndex(dd, v);

    Rd = cuddZddProduct(dd, fd, gd);
    if (Rd == NULL) {
        Cudd_RecursiveDerefZdd(dd, f1);
        Cudd_RecursiveDerefZdd(dd, f0);
        Cudd_RecursiveDerefZdd(dd, fd);
        Cudd_RecursiveDerefZdd(dd, g1);
        Cudd_RecursiveDerefZdd(dd, g0);
        Cudd_RecursiveDerefZdd(dd, gd);
        return(NULL);
    }
    Cudd_Ref(Rd);

    term1 = cuddZddProduct(dd, f0, g0);
    if (term1 == NULL) {
        Cudd_RecursiveDerefZdd(dd, f1);
        Cudd_RecursiveDerefZdd(dd, f0);
        Cudd_RecursiveDerefZdd(dd, fd);
        Cudd_RecursiveDerefZdd(dd, g1);
        Cudd_RecursiveDerefZdd(dd, g0);
        Cudd_RecursiveDerefZdd(dd, gd);
        Cudd_RecursiveDerefZdd(dd, Rd);
        return(NULL);
    }
    Cudd_Ref(term1);
    term2 = cuddZddProduct(dd, f0, gd);
    if (term2 == NULL) {
        Cudd_RecursiveDerefZdd(dd, f1);
        Cudd_RecursiveDerefZdd(dd, f0);
        Cudd_RecursiveDerefZdd(dd, fd);
        Cudd_RecursiveDerefZdd(dd, g1);
        Cudd_RecursiveDerefZdd(dd, g0);
        Cudd_RecursiveDerefZdd(dd, gd);
        Cudd_RecursiveDerefZdd(dd, Rd);
        Cudd_RecursiveDerefZdd(dd, term1);
        return(NULL);
    }
    Cudd_Ref(term2);
    term3 = cuddZddProduct(dd, fd, g0);
    if (term3 == NULL) {
        Cudd_RecursiveDerefZdd(dd, f1);
        Cudd_RecursiveDerefZdd(dd, f0);
        Cudd_RecursiveDerefZdd(dd, fd);
        Cudd_RecursiveDerefZdd(dd, g1);
        Cudd_RecursiveDerefZdd(dd, g0);
        Cudd_RecursiveDerefZdd(dd, gd);
        Cudd_RecursiveDerefZdd(dd, Rd);
        Cudd_RecursiveDerefZdd(dd, term1);
        Cudd_RecursiveDerefZdd(dd, term2);
        return(NULL);
    }
    Cudd_Ref(term3);
    Cudd_RecursiveDerefZdd(dd, f0);
    Cudd_RecursiveDerefZdd(dd, g0);
    tmp = cuddZddUnion(dd, term1, term2);
    if (tmp == NULL) {
        Cudd_RecursiveDerefZdd(dd, f1);
        Cudd_RecursiveDerefZdd(dd, fd);
        Cudd_RecursiveDerefZdd(dd, g1);
        Cudd_RecursiveDerefZdd(dd, gd);
        Cudd_RecursiveDerefZdd(dd, Rd);
        Cudd_RecursiveDerefZdd(dd, term1);
        Cudd_RecursiveDerefZdd(dd, term2);
        Cudd_RecursiveDerefZdd(dd, term3);
        return(NULL);
    }
    Cudd_Ref(tmp);
    Cudd_RecursiveDerefZdd(dd, term1);
    Cudd_RecursiveDerefZdd(dd, term2);
    R0 = cuddZddUnion(dd, tmp, term3);
    if (R0 == NULL) {
        Cudd_RecursiveDerefZdd(dd, f1);
        Cudd_RecursiveDerefZdd(dd, fd);
        Cudd_RecursiveDerefZdd(dd, g1);
        Cudd_RecursiveDerefZdd(dd, gd);
        Cudd_RecursiveDerefZdd(dd, Rd);
        Cudd_RecursiveDerefZdd(dd, term3);
        Cudd_RecursiveDerefZdd(dd, tmp);
        return(NULL);
    }
    Cudd_Ref(R0);
    Cudd_RecursiveDerefZdd(dd, tmp);
    Cudd_RecursiveDerefZdd(dd, term3);
    N0 = cuddZddGetNode(dd, nv, R0, Rd); /* nv = zi */
    if (N0 == NULL) {
        Cudd_RecursiveDerefZdd(dd, f1);
        Cudd_RecursiveDerefZdd(dd, fd);
        Cudd_RecursiveDerefZdd(dd, g1);
        Cudd_RecursiveDerefZdd(dd, gd);
        Cudd_RecursiveDerefZdd(dd, Rd);
        Cudd_RecursiveDerefZdd(dd, R0);
        return(NULL);
    }
    Cudd_Ref(N0);
    Cudd_RecursiveDerefZdd(dd, R0);
    Cudd_RecursiveDerefZdd(dd, Rd);

    term1 = cuddZddProduct(dd, f1, g1);
    if (term1 == NULL) {
        Cudd_RecursiveDerefZdd(dd, f1);
        Cudd_RecursiveDerefZdd(dd, fd);
        Cudd_RecursiveDerefZdd(dd, g1);
        Cudd_RecursiveDerefZdd(dd, gd);
        Cudd_RecursiveDerefZdd(dd, N0);
        return(NULL);
    }
    Cudd_Ref(term1);
    term2 = cuddZddProduct(dd, f1, gd);
    if (term2 == NULL) {
        Cudd_RecursiveDerefZdd(dd, f1);
        Cudd_RecursiveDerefZdd(dd, fd);
        Cudd_RecursiveDerefZdd(dd, g1);
        Cudd_RecursiveDerefZdd(dd, gd);
        Cudd_RecursiveDerefZdd(dd, N0);
        Cudd_RecursiveDerefZdd(dd, term1);
        return(NULL);
    }
    Cudd_Ref(term2);
    term3 = cuddZddProduct(dd, fd, g1);
    if (term3 == NULL) {
        Cudd_RecursiveDerefZdd(dd, f1);
        Cudd_RecursiveDerefZdd(dd, fd);
        Cudd_RecursiveDerefZdd(dd, g1);
        Cudd_RecursiveDerefZdd(dd, gd);
        Cudd_RecursiveDerefZdd(dd, N0);
        Cudd_RecursiveDerefZdd(dd, term1);
        Cudd_RecursiveDerefZdd(dd, term2);
        return(NULL);
    }
    Cudd_Ref(term3);
    Cudd_RecursiveDerefZdd(dd, f1);
    Cudd_RecursiveDerefZdd(dd, g1);
    Cudd_RecursiveDerefZdd(dd, fd);
    Cudd_RecursiveDerefZdd(dd, gd);
    tmp = cuddZddUnion(dd, term1, term2);
    if (tmp == NULL) {
        Cudd_RecursiveDerefZdd(dd, N0);
        Cudd_RecursiveDerefZdd(dd, term1);
        Cudd_RecursiveDerefZdd(dd, term2);
        Cudd_RecursiveDerefZdd(dd, term3);
        return(NULL);
    }
    Cudd_Ref(tmp);
    Cudd_RecursiveDerefZdd(dd, term1);
    Cudd_RecursiveDerefZdd(dd, term2);
    R1 = cuddZddUnion(dd, tmp, term3);
    if (R1 == NULL) {
        Cudd_RecursiveDerefZdd(dd, N0);
        Cudd_RecursiveDerefZdd(dd, term3);
        Cudd_RecursiveDerefZdd(dd, tmp);
        return(NULL);
    }
    Cudd_Ref(R1);
    Cudd_RecursiveDerefZdd(dd, tmp);
    Cudd_RecursiveDerefZdd(dd, term3);
    N1 = cuddZddGetNode(dd, pv, R1, N0); /* pv = yi */
    if (N1 == NULL) {
        Cudd_RecursiveDerefZdd(dd, N0);
        Cudd_RecursiveDerefZdd(dd, R1);
        return(NULL);
    }
    Cudd_Ref(N1);
    Cudd_RecursiveDerefZdd(dd, R1);
    Cudd_RecursiveDerefZdd(dd, N0);

    cuddCacheInsert2(dd, cuddZddProduct, f, g, N1);
    Cudd_Deref(N1);
    return(N1);

} /* end of cuddZddProduct */

DdNode* cuddZddUnateProduct	(	DdManager *	dd,
		DdNode *	f,
		DdNode *	g
	)

Function********************************************************************

Synopsis [Performs the recursive step of Cudd_zddUnateProduct.]

Description []

SideEffects [None]

SeeAlso [Cudd_zddUnateProduct]

Definition at line 617 of file cuddZddFuncs.c.

{
    int         v, top_f, top_g;
    DdNode      *term1, *term2, *term3, *term4;
    DdNode      *sum1, *sum2;
    DdNode      *f0, *f1, *g0, *g1;
    DdNode      *r;
    DdNode      *one = DD_ONE(dd);
    DdNode      *zero = DD_ZERO(dd);
    int         flag;

    statLine(dd);
    if (f == zero || g == zero)
        return(zero);
    if (f == one)
        return(g);
    if (g == one)
        return(f);

    top_f = dd->permZ[f->index];
    top_g = dd->permZ[g->index];

    if (top_f > top_g)
        return(cuddZddUnateProduct(dd, g, f));

    /* Check cache */
    r = cuddCacheLookup2Zdd(dd, cuddZddUnateProduct, f, g);
    if (r)
        return(r);

    v = f->index;       /* either yi or zi */
    flag = cuddZddGetCofactors2(dd, f, v, &f1, &f0);
    if (flag == 1)
        return(NULL);
    Cudd_Ref(f1);
    Cudd_Ref(f0);
    flag = cuddZddGetCofactors2(dd, g, v, &g1, &g0);
    if (flag == 1) {
        Cudd_RecursiveDerefZdd(dd, f1);
        Cudd_RecursiveDerefZdd(dd, f0);
        return(NULL);
    }
    Cudd_Ref(g1);
    Cudd_Ref(g0);

    term1 = cuddZddUnateProduct(dd, f1, g1);
    if (term1 == NULL) {
        Cudd_RecursiveDerefZdd(dd, f1);
        Cudd_RecursiveDerefZdd(dd, f0);
        Cudd_RecursiveDerefZdd(dd, g1);
        Cudd_RecursiveDerefZdd(dd, g0);
        return(NULL);
    }
    Cudd_Ref(term1);
    term2 = cuddZddUnateProduct(dd, f1, g0);
    if (term2 == NULL) {
        Cudd_RecursiveDerefZdd(dd, f1);
        Cudd_RecursiveDerefZdd(dd, f0);
        Cudd_RecursiveDerefZdd(dd, g1);
        Cudd_RecursiveDerefZdd(dd, g0);
        Cudd_RecursiveDerefZdd(dd, term1);
        return(NULL);
    }
    Cudd_Ref(term2);
    term3 = cuddZddUnateProduct(dd, f0, g1);
    if (term3 == NULL) {
        Cudd_RecursiveDerefZdd(dd, f1);
        Cudd_RecursiveDerefZdd(dd, f0);
        Cudd_RecursiveDerefZdd(dd, g1);
        Cudd_RecursiveDerefZdd(dd, g0);
        Cudd_RecursiveDerefZdd(dd, term1);
        Cudd_RecursiveDerefZdd(dd, term2);
        return(NULL);
    }
    Cudd_Ref(term3);
    term4 = cuddZddUnateProduct(dd, f0, g0);
    if (term4 == NULL) {
        Cudd_RecursiveDerefZdd(dd, f1);
        Cudd_RecursiveDerefZdd(dd, f0);
        Cudd_RecursiveDerefZdd(dd, g1);
        Cudd_RecursiveDerefZdd(dd, g0);
        Cudd_RecursiveDerefZdd(dd, term1);
        Cudd_RecursiveDerefZdd(dd, term2);
        Cudd_RecursiveDerefZdd(dd, term3);
        return(NULL);
    }
    Cudd_Ref(term4);
    Cudd_RecursiveDerefZdd(dd, f1);
    Cudd_RecursiveDerefZdd(dd, f0);
    Cudd_RecursiveDerefZdd(dd, g1);
    Cudd_RecursiveDerefZdd(dd, g0);
    sum1 = cuddZddUnion(dd, term1, term2);
    if (sum1 == NULL) {
        Cudd_RecursiveDerefZdd(dd, term1);
        Cudd_RecursiveDerefZdd(dd, term2);
        Cudd_RecursiveDerefZdd(dd, term3);
        Cudd_RecursiveDerefZdd(dd, term4);
        return(NULL);
    }
    Cudd_Ref(sum1);
    Cudd_RecursiveDerefZdd(dd, term1);
    Cudd_RecursiveDerefZdd(dd, term2);
    sum2 = cuddZddUnion(dd, sum1, term3);
    if (sum2 == NULL) {
        Cudd_RecursiveDerefZdd(dd, term3);
        Cudd_RecursiveDerefZdd(dd, term4);
        Cudd_RecursiveDerefZdd(dd, sum1);
        return(NULL);
    }
    Cudd_Ref(sum2);
    Cudd_RecursiveDerefZdd(dd, sum1);
    Cudd_RecursiveDerefZdd(dd, term3);
    r = cuddZddGetNode(dd, v, sum2, term4);
    if (r == NULL) {
        Cudd_RecursiveDerefZdd(dd, term4);
        Cudd_RecursiveDerefZdd(dd, sum2);
        return(NULL);
    }
    Cudd_Ref(r);
    Cudd_RecursiveDerefZdd(dd, sum2);
    Cudd_RecursiveDerefZdd(dd, term4);

    cuddCacheInsert2(dd, cuddZddUnateProduct, f, g, r);
    Cudd_Deref(r);
    return(r);

} /* end of cuddZddUnateProduct */

DdNode* cuddZddWeakDiv	(	DdManager *	dd,
		DdNode *	f,
		DdNode *	g
	)

Function********************************************************************

Synopsis [Performs the recursive step of Cudd_zddWeakDiv.]

Description []

SideEffects [None]

SeeAlso [Cudd_zddWeakDiv]

Definition at line 761 of file cuddZddFuncs.c.

{
    int         v;
    DdNode      *one = DD_ONE(dd);
    DdNode      *zero = DD_ZERO(dd);
    DdNode      *f0, *f1, *fd, *g0, *g1, *gd;
    DdNode      *q, *tmp;
    DdNode      *r;
    int         flag;

    statLine(dd);
    if (g == one)
        return(f);
    if (f == zero || f == one)
        return(zero);
    if (f == g)
        return(one);

    /* Check cache. */
    r = cuddCacheLookup2Zdd(dd, cuddZddWeakDiv, f, g);
    if (r)
        return(r);

    v = g->index;

    flag = cuddZddGetCofactors3(dd, f, v, &f1, &f0, &fd);
    if (flag == 1)
        return(NULL);
    Cudd_Ref(f1);
    Cudd_Ref(f0);
    Cudd_Ref(fd);
    flag = cuddZddGetCofactors3(dd, g, v, &g1, &g0, &gd);
    if (flag == 1) {
        Cudd_RecursiveDerefZdd(dd, f1);
        Cudd_RecursiveDerefZdd(dd, f0);
        Cudd_RecursiveDerefZdd(dd, fd);
        return(NULL);
    }
    Cudd_Ref(g1);
    Cudd_Ref(g0);
    Cudd_Ref(gd);

    q = g;

    if (g0 != zero) {
        q = cuddZddWeakDiv(dd, f0, g0);
        if (q == NULL) {
            Cudd_RecursiveDerefZdd(dd, f1);
            Cudd_RecursiveDerefZdd(dd, f0);
            Cudd_RecursiveDerefZdd(dd, fd);
            Cudd_RecursiveDerefZdd(dd, g1);
            Cudd_RecursiveDerefZdd(dd, g0);
            Cudd_RecursiveDerefZdd(dd, gd);
            return(NULL);
        }
        Cudd_Ref(q);
    }
    else
        Cudd_Ref(q);
    Cudd_RecursiveDerefZdd(dd, f0);
    Cudd_RecursiveDerefZdd(dd, g0);

    if (q == zero) {
        Cudd_RecursiveDerefZdd(dd, f1);
        Cudd_RecursiveDerefZdd(dd, g1);
        Cudd_RecursiveDerefZdd(dd, fd);
        Cudd_RecursiveDerefZdd(dd, gd);
        cuddCacheInsert2(dd, cuddZddWeakDiv, f, g, zero);
        Cudd_Deref(q);
        return(zero);
    }

    if (g1 != zero) {
        Cudd_RecursiveDerefZdd(dd, q);
        tmp = cuddZddWeakDiv(dd, f1, g1);
        if (tmp == NULL) {
            Cudd_RecursiveDerefZdd(dd, f1);
            Cudd_RecursiveDerefZdd(dd, g1);
            Cudd_RecursiveDerefZdd(dd, fd);
            Cudd_RecursiveDerefZdd(dd, gd);
            return(NULL);
        }
        Cudd_Ref(tmp);
        Cudd_RecursiveDerefZdd(dd, f1);
        Cudd_RecursiveDerefZdd(dd, g1);
        if (q == g)
            q = tmp;
        else {
            q = cuddZddIntersect(dd, q, tmp);
            if (q == NULL) {
                Cudd_RecursiveDerefZdd(dd, fd);
                Cudd_RecursiveDerefZdd(dd, gd);
                return(NULL);
            }
            Cudd_Ref(q);
            Cudd_RecursiveDerefZdd(dd, tmp);
        }
    }
    else {
        Cudd_RecursiveDerefZdd(dd, f1);
        Cudd_RecursiveDerefZdd(dd, g1);
    }

    if (q == zero) {
        Cudd_RecursiveDerefZdd(dd, fd);
        Cudd_RecursiveDerefZdd(dd, gd);
        cuddCacheInsert2(dd, cuddZddWeakDiv, f, g, zero);
        Cudd_Deref(q);
        return(zero);
    }

    if (gd != zero) {
        Cudd_RecursiveDerefZdd(dd, q);
        tmp = cuddZddWeakDiv(dd, fd, gd);
        if (tmp == NULL) {
            Cudd_RecursiveDerefZdd(dd, fd);
            Cudd_RecursiveDerefZdd(dd, gd);
            return(NULL);
        }
        Cudd_Ref(tmp);
        Cudd_RecursiveDerefZdd(dd, fd);
        Cudd_RecursiveDerefZdd(dd, gd);
        if (q == g)
            q = tmp;
        else {
            q = cuddZddIntersect(dd, q, tmp);
            if (q == NULL) {
                Cudd_RecursiveDerefZdd(dd, tmp);
                return(NULL);
            }
            Cudd_Ref(q);
            Cudd_RecursiveDerefZdd(dd, tmp);
        }
    }
    else {
        Cudd_RecursiveDerefZdd(dd, fd);
        Cudd_RecursiveDerefZdd(dd, gd);
    }

    cuddCacheInsert2(dd, cuddZddWeakDiv, f, g, q);
    Cudd_Deref(q);
    return(q);

} /* end of cuddZddWeakDiv */

DdNode* cuddZddWeakDivF	(	DdManager *	dd,
		DdNode *	f,
		DdNode *	g
	)

Function********************************************************************

Synopsis [Performs the recursive step of Cudd_zddWeakDivF.]

Description []

SideEffects [None]

SeeAlso [Cudd_zddWeakDivF]

Definition at line 922 of file cuddZddFuncs.c.

{
    int         v, top_f, top_g, vf, vg;
    DdNode      *one = DD_ONE(dd);
    DdNode      *zero = DD_ZERO(dd);
    DdNode      *f0, *f1, *fd, *g0, *g1, *gd;
    DdNode      *q, *tmp;
    DdNode      *r;
    DdNode      *term1, *term0, *termd;
    int         flag;
    int         pv, nv;

    statLine(dd);
    if (g == one)
        return(f);
    if (f == zero || f == one)
        return(zero);
    if (f == g)
        return(one);

    /* Check cache. */
    r = cuddCacheLookup2Zdd(dd, cuddZddWeakDivF, f, g);
    if (r)
        return(r);

    top_f = dd->permZ[f->index];
    top_g = dd->permZ[g->index];
    vf = top_f >> 1;
    vg = top_g >> 1;
    v = ddMin(top_f, top_g);

    if (v == top_f && vf < vg) {
        v = f->index;
        flag = cuddZddGetCofactors3(dd, f, v, &f1, &f0, &fd);
        if (flag == 1)
            return(NULL);
        Cudd_Ref(f1);
        Cudd_Ref(f0);
        Cudd_Ref(fd);

        pv = cuddZddGetPosVarIndex(dd, v);
        nv = cuddZddGetNegVarIndex(dd, v);

        term1 = cuddZddWeakDivF(dd, f1, g);
        if (term1 == NULL) {
            Cudd_RecursiveDerefZdd(dd, f1);
            Cudd_RecursiveDerefZdd(dd, f0);
            Cudd_RecursiveDerefZdd(dd, fd);
            return(NULL);
        }
        Cudd_Ref(term1);
        Cudd_RecursiveDerefZdd(dd, f1);
        term0 = cuddZddWeakDivF(dd, f0, g);
        if (term0 == NULL) {
            Cudd_RecursiveDerefZdd(dd, f0);
            Cudd_RecursiveDerefZdd(dd, fd);
            Cudd_RecursiveDerefZdd(dd, term1);
            return(NULL);
        }
        Cudd_Ref(term0);
        Cudd_RecursiveDerefZdd(dd, f0);
        termd = cuddZddWeakDivF(dd, fd, g);
        if (termd == NULL) {
            Cudd_RecursiveDerefZdd(dd, fd);
            Cudd_RecursiveDerefZdd(dd, term1);
            Cudd_RecursiveDerefZdd(dd, term0);
            return(NULL);
        }
        Cudd_Ref(termd);
        Cudd_RecursiveDerefZdd(dd, fd);

        tmp = cuddZddGetNode(dd, nv, term0, termd); /* nv = zi */
        if (tmp == NULL) {
            Cudd_RecursiveDerefZdd(dd, term1);
            Cudd_RecursiveDerefZdd(dd, term0);
            Cudd_RecursiveDerefZdd(dd, termd);
            return(NULL);
        }
        Cudd_Ref(tmp);
        Cudd_RecursiveDerefZdd(dd, term0);
        Cudd_RecursiveDerefZdd(dd, termd);
        q = cuddZddGetNode(dd, pv, term1, tmp); /* pv = yi */
        if (q == NULL) {
            Cudd_RecursiveDerefZdd(dd, term1);
            Cudd_RecursiveDerefZdd(dd, tmp);
            return(NULL);
        }
        Cudd_Ref(q);
        Cudd_RecursiveDerefZdd(dd, term1);
        Cudd_RecursiveDerefZdd(dd, tmp);

        cuddCacheInsert2(dd, cuddZddWeakDivF, f, g, q);
        Cudd_Deref(q);
        return(q);
    }

    if (v == top_f)
        v = f->index;
    else
        v = g->index;

    flag = cuddZddGetCofactors3(dd, f, v, &f1, &f0, &fd);
    if (flag == 1)
        return(NULL);
    Cudd_Ref(f1);
    Cudd_Ref(f0);
    Cudd_Ref(fd);
    flag = cuddZddGetCofactors3(dd, g, v, &g1, &g0, &gd);
    if (flag == 1) {
        Cudd_RecursiveDerefZdd(dd, f1);
        Cudd_RecursiveDerefZdd(dd, f0);
        Cudd_RecursiveDerefZdd(dd, fd);
        return(NULL);
    }
    Cudd_Ref(g1);
    Cudd_Ref(g0);
    Cudd_Ref(gd);

    q = g;

    if (g0 != zero) {
        q = cuddZddWeakDivF(dd, f0, g0);
        if (q == NULL) {
            Cudd_RecursiveDerefZdd(dd, f1);
            Cudd_RecursiveDerefZdd(dd, f0);
            Cudd_RecursiveDerefZdd(dd, fd);
            Cudd_RecursiveDerefZdd(dd, g1);
            Cudd_RecursiveDerefZdd(dd, g0);
            Cudd_RecursiveDerefZdd(dd, gd);
            return(NULL);
        }
        Cudd_Ref(q);
    }
    else
        Cudd_Ref(q);
    Cudd_RecursiveDerefZdd(dd, f0);
    Cudd_RecursiveDerefZdd(dd, g0);

    if (q == zero) {
        Cudd_RecursiveDerefZdd(dd, f1);
        Cudd_RecursiveDerefZdd(dd, g1);
        Cudd_RecursiveDerefZdd(dd, fd);
        Cudd_RecursiveDerefZdd(dd, gd);
        cuddCacheInsert2(dd, cuddZddWeakDivF, f, g, zero);
        Cudd_Deref(q);
        return(zero);
    }

    if (g1 != zero) {
        Cudd_RecursiveDerefZdd(dd, q);
        tmp = cuddZddWeakDivF(dd, f1, g1);
        if (tmp == NULL) {
            Cudd_RecursiveDerefZdd(dd, f1);
            Cudd_RecursiveDerefZdd(dd, g1);
            Cudd_RecursiveDerefZdd(dd, fd);
            Cudd_RecursiveDerefZdd(dd, gd);
            return(NULL);
        }
        Cudd_Ref(tmp);
        Cudd_RecursiveDerefZdd(dd, f1);
        Cudd_RecursiveDerefZdd(dd, g1);
        if (q == g)
            q = tmp;
        else {
            q = cuddZddIntersect(dd, q, tmp);
            if (q == NULL) {
                Cudd_RecursiveDerefZdd(dd, fd);
                Cudd_RecursiveDerefZdd(dd, gd);
                return(NULL);
            }
            Cudd_Ref(q);
            Cudd_RecursiveDerefZdd(dd, tmp);
        }
    }
    else {
        Cudd_RecursiveDerefZdd(dd, f1);
        Cudd_RecursiveDerefZdd(dd, g1);
    }

    if (q == zero) {
        Cudd_RecursiveDerefZdd(dd, fd);
        Cudd_RecursiveDerefZdd(dd, gd);
        cuddCacheInsert2(dd, cuddZddWeakDivF, f, g, zero);
        Cudd_Deref(q);
        return(zero);
    }

    if (gd != zero) {
        Cudd_RecursiveDerefZdd(dd, q);
        tmp = cuddZddWeakDivF(dd, fd, gd);
        if (tmp == NULL) {
            Cudd_RecursiveDerefZdd(dd, fd);
            Cudd_RecursiveDerefZdd(dd, gd);
            return(NULL);
        }
        Cudd_Ref(tmp);
        Cudd_RecursiveDerefZdd(dd, fd);
        Cudd_RecursiveDerefZdd(dd, gd);
        if (q == g)
            q = tmp;
        else {
            q = cuddZddIntersect(dd, q, tmp);
            if (q == NULL) {
                Cudd_RecursiveDerefZdd(dd, tmp);
                return(NULL);
            }
            Cudd_Ref(q);
            Cudd_RecursiveDerefZdd(dd, tmp);
        }
    }
    else {
        Cudd_RecursiveDerefZdd(dd, fd);
        Cudd_RecursiveDerefZdd(dd, gd);
    }

    cuddCacheInsert2(dd, cuddZddWeakDivF, f, g, q);
    Cudd_Deref(q);
    return(q);

} /* end of cuddZddWeakDivF */

Variable Documentation

ABC_NAMESPACE_IMPL_START char rcsid [] DD_UNUSED = "$Id: cuddZddFuncs.c,v 1.16 2008/04/25 07:39:33 fabio Exp $"

static

CFile***********************************************************************

FileName [cuddZddFuncs.c]

PackageName [cudd]

Synopsis [Functions to manipulate covers represented as ZDDs.]

Description [External procedures included in this module:

• Cudd_zddProduct();
• Cudd_zddUnateProduct();
• Cudd_zddWeakDiv();
• Cudd_zddWeakDivF();
• Cudd_zddDivide();
• Cudd_zddDivideF();
• Cudd_zddComplement();

Internal procedures included in this module:

• cuddZddProduct();
• cuddZddUnateProduct();
• cuddZddWeakDiv();
• cuddZddWeakDivF();
• cuddZddDivide();
• cuddZddDivideF();
• cuddZddGetCofactors3()
• cuddZddGetCofactors2()
• cuddZddComplement();
• cuddZddGetPosVarIndex();
• cuddZddGetNegVarIndex();
• cuddZddGetPosVarLevel();
• cuddZddGetNegVarLevel();

Static procedures included in this module:

]

SeeAlso []

Author [In-Ho Moon]

Copyright [Copyright (c) 1995-2004, Regents of the University of Colorado

All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

Neither the name of the University of Colorado nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.]

Definition at line 105 of file cuddZddFuncs.c.