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1080 lines
23 KiB
1080 lines
23 KiB
/**
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@file
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@ingroup cudd
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@brief Set operations on ZDDs.
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@author Hyong-Kyoon Shin, In-Ho Moon
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@copyright@parblock
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Copyright (c) 1995-2015, Regents of the University of Colorado
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All rights reserved.
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions
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are met:
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Redistributions of source code must retain the above copyright
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notice, this list of conditions and the following disclaimer.
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Redistributions in binary form must reproduce the above copyright
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notice, this list of conditions and the following disclaimer in the
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documentation and/or other materials provided with the distribution.
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Neither the name of the University of Colorado nor the names of its
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contributors may be used to endorse or promote products derived from
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this software without specific prior written permission.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
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CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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POSSIBILITY OF SUCH DAMAGE.
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@endparblock
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*/
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#include "util.h"
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#include "cuddInt.h"
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/*---------------------------------------------------------------------------*/
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/* Constant declarations */
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/*---------------------------------------------------------------------------*/
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/*---------------------------------------------------------------------------*/
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/* Stucture declarations */
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/*---------------------------------------------------------------------------*/
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/*---------------------------------------------------------------------------*/
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/* Type declarations */
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/*---------------------------------------------------------------------------*/
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/*---------------------------------------------------------------------------*/
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/* Variable declarations */
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/*---------------------------------------------------------------------------*/
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/*---------------------------------------------------------------------------*/
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/* Macro declarations */
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/*---------------------------------------------------------------------------*/
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/** \cond */
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/*---------------------------------------------------------------------------*/
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/* Static function prototypes */
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/*---------------------------------------------------------------------------*/
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static DdNode * zdd_subset1_aux (DdManager *zdd, DdNode *P, DdNode *zvar);
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static DdNode * zdd_subset0_aux (DdManager *zdd, DdNode *P, DdNode *zvar);
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static void zddVarToConst (DdNode *f, DdNode **gp, DdNode **hp, DdNode *base, DdNode *empty);
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/** \endcond */
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/*---------------------------------------------------------------------------*/
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/* Definition of exported functions */
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/*---------------------------------------------------------------------------*/
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/**
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@brief Computes the ITE of three ZDDs.
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@return a pointer to the result if successful; NULL otherwise.
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@sideeffect None
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*/
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DdNode *
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Cudd_zddIte(
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DdManager * dd,
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DdNode * f,
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DdNode * g,
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DdNode * h)
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{
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DdNode *res;
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do {
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dd->reordered = 0;
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res = cuddZddIte(dd, f, g, h);
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} while (dd->reordered == 1);
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if (dd->errorCode == CUDD_TIMEOUT_EXPIRED && dd->timeoutHandler) {
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dd->timeoutHandler(dd, dd->tohArg);
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}
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return(res);
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} /* end of Cudd_zddIte */
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/**
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@brief Computes the union of two ZDDs.
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@return a pointer to the result if successful; NULL otherwise.
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@sideeffect None
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*/
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DdNode *
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Cudd_zddUnion(
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DdManager * dd,
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DdNode * P,
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DdNode * Q)
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{
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DdNode *res;
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do {
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dd->reordered = 0;
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res = cuddZddUnion(dd, P, Q);
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} while (dd->reordered == 1);
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if (dd->errorCode == CUDD_TIMEOUT_EXPIRED && dd->timeoutHandler) {
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dd->timeoutHandler(dd, dd->tohArg);
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}
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return(res);
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} /* end of Cudd_zddUnion */
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/**
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@brief Computes the intersection of two ZDDs.
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@return a pointer to the result if successful; NULL otherwise.
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@sideeffect None
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*/
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DdNode *
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Cudd_zddIntersect(
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DdManager * dd,
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DdNode * P,
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DdNode * Q)
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{
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DdNode *res;
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do {
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dd->reordered = 0;
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res = cuddZddIntersect(dd, P, Q);
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} while (dd->reordered == 1);
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if (dd->errorCode == CUDD_TIMEOUT_EXPIRED && dd->timeoutHandler) {
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dd->timeoutHandler(dd, dd->tohArg);
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}
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return(res);
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} /* end of Cudd_zddIntersect */
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/**
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@brief Computes the difference of two ZDDs.
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@return a pointer to the result if successful; NULL otherwise.
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@sideeffect None
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*/
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DdNode *
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Cudd_zddDiff(
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DdManager * dd,
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DdNode * P,
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DdNode * Q)
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{
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DdNode *res;
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do {
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dd->reordered = 0;
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res = cuddZddDiff(dd, P, Q);
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} while (dd->reordered == 1);
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if (dd->errorCode == CUDD_TIMEOUT_EXPIRED && dd->timeoutHandler) {
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dd->timeoutHandler(dd, dd->tohArg);
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}
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return(res);
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} /* end of Cudd_zddDiff */
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/**
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@brief Performs the inclusion test for ZDDs (P implies Q).
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@details No new nodes are generated by this procedure.
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@return empty if true; a valid pointer different from empty or
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DD_NON_CONSTANT otherwise.
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@sideeffect None
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@see Cudd_zddDiff
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*/
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DdNode *
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Cudd_zddDiffConst(
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DdManager * zdd,
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DdNode * P,
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DdNode * Q)
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{
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int p_top, q_top;
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DdNode *empty = DD_ZERO(zdd), *t, *res;
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DdManager *table = zdd;
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statLine(zdd);
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if (P == empty)
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return(empty);
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if (Q == empty)
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return(P);
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if (P == Q)
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return(empty);
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/* Check cache. The cache is shared by cuddZddDiff(). */
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res = cuddCacheLookup2Zdd(table, cuddZddDiff, P, Q);
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if (res != NULL)
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return(res);
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if (cuddIsConstant(P))
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p_top = P->index;
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else
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p_top = zdd->permZ[P->index];
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if (cuddIsConstant(Q))
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q_top = Q->index;
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else
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q_top = zdd->permZ[Q->index];
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if (p_top < q_top) {
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res = DD_NON_CONSTANT;
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} else if (p_top > q_top) {
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res = Cudd_zddDiffConst(zdd, P, cuddE(Q));
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} else {
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t = Cudd_zddDiffConst(zdd, cuddT(P), cuddT(Q));
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if (t != empty)
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res = DD_NON_CONSTANT;
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else
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res = Cudd_zddDiffConst(zdd, cuddE(P), cuddE(Q));
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}
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cuddCacheInsert2(table, cuddZddDiff, P, Q, res);
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return(res);
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} /* end of Cudd_zddDiffConst */
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/**
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@brief Computes the positive cofactor of a %ZDD w.r.t. a variable.
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@details In terms of combinations, the result is the set of all
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combinations in which the variable is asserted.
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@return a pointer to the result if successful; NULL otherwise.
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@sideeffect None
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@see Cudd_zddSubset0
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*/
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DdNode *
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Cudd_zddSubset1(
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DdManager * dd,
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DdNode * P,
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int var)
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{
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DdNode *r;
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do {
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dd->reordered = 0;
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r = cuddZddSubset1(dd, P, var);
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} while (dd->reordered == 1);
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if (dd->errorCode == CUDD_TIMEOUT_EXPIRED && dd->timeoutHandler) {
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dd->timeoutHandler(dd, dd->tohArg);
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}
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return(r);
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} /* end of Cudd_zddSubset1 */
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/**
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@brief Computes the negative cofactor of a %ZDD w.r.t. a variable.
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@details In terms of combinations, the result is the set of all
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combinations in which the variable is negated.
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@return a pointer to the result if successful; NULL otherwise.
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@sideeffect None
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@see Cudd_zddSubset1
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*/
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DdNode *
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Cudd_zddSubset0(
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DdManager * dd,
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DdNode * P,
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int var)
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{
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DdNode *r;
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do {
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dd->reordered = 0;
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r = cuddZddSubset0(dd, P, var);
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} while (dd->reordered == 1);
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if (dd->errorCode == CUDD_TIMEOUT_EXPIRED && dd->timeoutHandler) {
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dd->timeoutHandler(dd, dd->tohArg);
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}
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return(r);
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} /* end of Cudd_zddSubset0 */
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/**
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@brief Substitutes a variable with its complement in a %ZDD.
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@return a pointer to the result if successful; NULL otherwise.
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@sideeffect None
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*/
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DdNode *
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Cudd_zddChange(
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DdManager * dd,
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DdNode * P,
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int var)
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{
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DdNode *res;
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if ((unsigned int) var >= CUDD_MAXINDEX - 1) return(NULL);
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do {
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dd->reordered = 0;
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res = cuddZddChange(dd, P, var);
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} while (dd->reordered == 1);
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if (dd->errorCode == CUDD_TIMEOUT_EXPIRED && dd->timeoutHandler) {
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dd->timeoutHandler(dd, dd->tohArg);
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}
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return(res);
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} /* end of Cudd_zddChange */
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/*---------------------------------------------------------------------------*/
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/* Definition of internal functions */
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/*---------------------------------------------------------------------------*/
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/**
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@brief Performs the recursive step of Cudd_zddIte.
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@sideeffect None
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*/
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DdNode *
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cuddZddIte(
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DdManager * dd,
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DdNode * f,
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DdNode * g,
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DdNode * h)
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{
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DdNode *tautology, *empty;
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DdNode *r,*Gv,*Gvn,*Hv,*Hvn,*t,*e;
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int topf,topg,toph,v,top;
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unsigned int index;
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statLine(dd);
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/* Trivial cases. */
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/* One variable cases. */
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if (f == (empty = DD_ZERO(dd))) { /* ITE(0,G,H) = H */
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return(h);
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}
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topf = cuddIZ(dd,f->index);
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topg = cuddIZ(dd,g->index);
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toph = cuddIZ(dd,h->index);
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v = ddMin(topg,toph);
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top = ddMin(topf,v);
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tautology = (top == CUDD_MAXINDEX) ? DD_ONE(dd) : dd->univ[top];
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if (f == tautology) { /* ITE(1,G,H) = G */
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return(g);
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}
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/* From now on, f is known to not be a constant. */
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zddVarToConst(f,&g,&h,tautology,empty);
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/* Check remaining one variable cases. */
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if (g == h) { /* ITE(F,G,G) = G */
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return(g);
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}
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if (g == tautology) { /* ITE(F,1,0) = F */
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if (h == empty) return(f);
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}
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/* Check cache. */
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r = cuddCacheLookupZdd(dd,DD_ZDD_ITE_TAG,f,g,h);
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if (r != NULL) {
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return(r);
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}
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/* Recompute these because they may have changed in zddVarToConst. */
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topg = cuddIZ(dd,g->index);
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toph = cuddIZ(dd,h->index);
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v = ddMin(topg,toph);
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if (topf < v) {
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r = cuddZddIte(dd,cuddE(f),g,h);
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if (r == NULL) return(NULL);
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} else if (topf > v) {
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if (topg > v) {
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Gvn = g;
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index = h->index;
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} else {
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Gvn = cuddE(g);
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index = g->index;
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}
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if (toph > v) {
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Hv = empty; Hvn = h;
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} else {
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Hv = cuddT(h); Hvn = cuddE(h);
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}
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e = cuddZddIte(dd,f,Gvn,Hvn);
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if (e == NULL) return(NULL);
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cuddRef(e);
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r = cuddZddGetNode(dd,index,Hv,e);
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if (r == NULL) {
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Cudd_RecursiveDerefZdd(dd,e);
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return(NULL);
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}
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cuddDeref(e);
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} else {
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index = f->index;
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if (topg > v) {
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Gv = empty; Gvn = g;
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} else {
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Gv = cuddT(g); Gvn = cuddE(g);
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}
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if (toph > v) {
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Hv = empty; Hvn = h;
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} else {
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Hv = cuddT(h); Hvn = cuddE(h);
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}
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e = cuddZddIte(dd,cuddE(f),Gvn,Hvn);
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if (e == NULL) return(NULL);
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cuddRef(e);
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t = cuddZddIte(dd,cuddT(f),Gv,Hv);
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if (t == NULL) {
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Cudd_RecursiveDerefZdd(dd,e);
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return(NULL);
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}
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cuddRef(t);
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r = cuddZddGetNode(dd,index,t,e);
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if (r == NULL) {
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Cudd_RecursiveDerefZdd(dd,e);
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Cudd_RecursiveDerefZdd(dd,t);
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return(NULL);
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}
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cuddDeref(t);
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cuddDeref(e);
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}
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cuddCacheInsert(dd,DD_ZDD_ITE_TAG,f,g,h,r);
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return(r);
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} /* end of cuddZddIte */
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/**
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@brief Performs the recursive step of Cudd_zddUnion.
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@sideeffect None
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*/
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DdNode *
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cuddZddUnion(
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DdManager * zdd,
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DdNode * P,
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DdNode * Q)
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{
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int p_top, q_top;
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DdNode *empty = DD_ZERO(zdd), *t, *e, *res;
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DdManager *table = zdd;
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statLine(zdd);
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if (P == empty)
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return(Q);
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if (Q == empty)
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return(P);
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if (P == Q)
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return(P);
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/* Check cache */
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res = cuddCacheLookup2Zdd(table, cuddZddUnion, P, Q);
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if (res != NULL)
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return(res);
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if (cuddIsConstant(P))
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p_top = P->index;
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else
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p_top = zdd->permZ[P->index];
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if (cuddIsConstant(Q))
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q_top = Q->index;
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else
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q_top = zdd->permZ[Q->index];
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if (p_top < q_top) {
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e = cuddZddUnion(zdd, cuddE(P), Q);
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if (e == NULL) return (NULL);
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cuddRef(e);
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res = cuddZddGetNode(zdd, P->index, cuddT(P), e);
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if (res == NULL) {
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Cudd_RecursiveDerefZdd(table, e);
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return(NULL);
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}
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cuddDeref(e);
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} else if (p_top > q_top) {
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e = cuddZddUnion(zdd, P, cuddE(Q));
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if (e == NULL) return(NULL);
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cuddRef(e);
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res = cuddZddGetNode(zdd, Q->index, cuddT(Q), e);
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if (res == NULL) {
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Cudd_RecursiveDerefZdd(table, e);
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return(NULL);
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}
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cuddDeref(e);
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} else {
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t = cuddZddUnion(zdd, cuddT(P), cuddT(Q));
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if (t == NULL) return(NULL);
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cuddRef(t);
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e = cuddZddUnion(zdd, cuddE(P), cuddE(Q));
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if (e == NULL) {
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Cudd_RecursiveDerefZdd(table, t);
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return(NULL);
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}
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cuddRef(e);
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res = cuddZddGetNode(zdd, P->index, t, e);
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if (res == NULL) {
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Cudd_RecursiveDerefZdd(table, t);
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Cudd_RecursiveDerefZdd(table, e);
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return(NULL);
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}
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cuddDeref(t);
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cuddDeref(e);
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}
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cuddCacheInsert2(table, cuddZddUnion, P, Q, res);
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return(res);
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|
|
|
} /* end of cuddZddUnion */
|
|
|
|
|
|
/**
|
|
@brief Performs the recursive step of Cudd_zddIntersect.
|
|
|
|
@sideeffect None
|
|
|
|
*/
|
|
DdNode *
|
|
cuddZddIntersect(
|
|
DdManager * zdd,
|
|
DdNode * P,
|
|
DdNode * Q)
|
|
{
|
|
int p_top, q_top;
|
|
DdNode *empty = DD_ZERO(zdd), *t, *e, *res;
|
|
DdManager *table = zdd;
|
|
|
|
statLine(zdd);
|
|
if (P == empty)
|
|
return(empty);
|
|
if (Q == empty)
|
|
return(empty);
|
|
if (P == Q)
|
|
return(P);
|
|
|
|
/* Check cache. */
|
|
res = cuddCacheLookup2Zdd(table, cuddZddIntersect, P, Q);
|
|
if (res != NULL)
|
|
return(res);
|
|
|
|
if (cuddIsConstant(P))
|
|
p_top = P->index;
|
|
else
|
|
p_top = zdd->permZ[P->index];
|
|
if (cuddIsConstant(Q))
|
|
q_top = Q->index;
|
|
else
|
|
q_top = zdd->permZ[Q->index];
|
|
if (p_top < q_top) {
|
|
res = cuddZddIntersect(zdd, cuddE(P), Q);
|
|
if (res == NULL) return(NULL);
|
|
} else if (p_top > q_top) {
|
|
res = cuddZddIntersect(zdd, P, cuddE(Q));
|
|
if (res == NULL) return(NULL);
|
|
} else {
|
|
t = cuddZddIntersect(zdd, cuddT(P), cuddT(Q));
|
|
if (t == NULL) return(NULL);
|
|
cuddRef(t);
|
|
e = cuddZddIntersect(zdd, cuddE(P), cuddE(Q));
|
|
if (e == NULL) {
|
|
Cudd_RecursiveDerefZdd(table, t);
|
|
return(NULL);
|
|
}
|
|
cuddRef(e);
|
|
res = cuddZddGetNode(zdd, P->index, t, e);
|
|
if (res == NULL) {
|
|
Cudd_RecursiveDerefZdd(table, t);
|
|
Cudd_RecursiveDerefZdd(table, e);
|
|
return(NULL);
|
|
}
|
|
cuddDeref(t);
|
|
cuddDeref(e);
|
|
}
|
|
|
|
cuddCacheInsert2(table, cuddZddIntersect, P, Q, res);
|
|
|
|
return(res);
|
|
|
|
} /* end of cuddZddIntersect */
|
|
|
|
|
|
/**
|
|
@brief Performs the recursive step of Cudd_zddDiff.
|
|
|
|
@sideeffect None
|
|
|
|
*/
|
|
DdNode *
|
|
cuddZddDiff(
|
|
DdManager * zdd,
|
|
DdNode * P,
|
|
DdNode * Q)
|
|
{
|
|
int p_top, q_top;
|
|
DdNode *empty = DD_ZERO(zdd), *t, *e, *res;
|
|
DdManager *table = zdd;
|
|
|
|
statLine(zdd);
|
|
if (P == empty)
|
|
return(empty);
|
|
if (Q == empty)
|
|
return(P);
|
|
if (P == Q)
|
|
return(empty);
|
|
|
|
/* Check cache. The cache is shared by Cudd_zddDiffConst(). */
|
|
res = cuddCacheLookup2Zdd(table, cuddZddDiff, P, Q);
|
|
if (res != NULL && res != DD_NON_CONSTANT)
|
|
return(res);
|
|
|
|
if (cuddIsConstant(P))
|
|
p_top = P->index;
|
|
else
|
|
p_top = zdd->permZ[P->index];
|
|
if (cuddIsConstant(Q))
|
|
q_top = Q->index;
|
|
else
|
|
q_top = zdd->permZ[Q->index];
|
|
if (p_top < q_top) {
|
|
e = cuddZddDiff(zdd, cuddE(P), Q);
|
|
if (e == NULL) return(NULL);
|
|
cuddRef(e);
|
|
res = cuddZddGetNode(zdd, P->index, cuddT(P), e);
|
|
if (res == NULL) {
|
|
Cudd_RecursiveDerefZdd(table, e);
|
|
return(NULL);
|
|
}
|
|
cuddDeref(e);
|
|
} else if (p_top > q_top) {
|
|
res = cuddZddDiff(zdd, P, cuddE(Q));
|
|
if (res == NULL) return(NULL);
|
|
} else {
|
|
t = cuddZddDiff(zdd, cuddT(P), cuddT(Q));
|
|
if (t == NULL) return(NULL);
|
|
cuddRef(t);
|
|
e = cuddZddDiff(zdd, cuddE(P), cuddE(Q));
|
|
if (e == NULL) {
|
|
Cudd_RecursiveDerefZdd(table, t);
|
|
return(NULL);
|
|
}
|
|
cuddRef(e);
|
|
res = cuddZddGetNode(zdd, P->index, t, e);
|
|
if (res == NULL) {
|
|
Cudd_RecursiveDerefZdd(table, t);
|
|
Cudd_RecursiveDerefZdd(table, e);
|
|
return(NULL);
|
|
}
|
|
cuddDeref(t);
|
|
cuddDeref(e);
|
|
}
|
|
|
|
cuddCacheInsert2(table, cuddZddDiff, P, Q, res);
|
|
|
|
return(res);
|
|
|
|
} /* end of cuddZddDiff */
|
|
|
|
|
|
/**
|
|
@brief Performs the recursive step of Cudd_zddChange.
|
|
|
|
@sideeffect None
|
|
|
|
*/
|
|
DdNode *
|
|
cuddZddChangeAux(
|
|
DdManager * zdd,
|
|
DdNode * P,
|
|
DdNode * zvar)
|
|
{
|
|
int top_var, level;
|
|
DdNode *res, *t, *e;
|
|
DdNode *base = DD_ONE(zdd);
|
|
DdNode *empty = DD_ZERO(zdd);
|
|
|
|
statLine(zdd);
|
|
if (P == empty)
|
|
return(empty);
|
|
if (P == base)
|
|
return(zvar);
|
|
|
|
/* Check cache. */
|
|
res = cuddCacheLookup2Zdd(zdd, cuddZddChangeAux, P, zvar);
|
|
if (res != NULL)
|
|
return(res);
|
|
|
|
top_var = zdd->permZ[P->index];
|
|
level = zdd->permZ[zvar->index];
|
|
|
|
if (top_var > level) {
|
|
res = cuddZddGetNode(zdd, zvar->index, P, DD_ZERO(zdd));
|
|
if (res == NULL) return(NULL);
|
|
} else if (top_var == level) {
|
|
res = cuddZddGetNode(zdd, zvar->index, cuddE(P), cuddT(P));
|
|
if (res == NULL) return(NULL);
|
|
} else {
|
|
t = cuddZddChangeAux(zdd, cuddT(P), zvar);
|
|
if (t == NULL) return(NULL);
|
|
cuddRef(t);
|
|
e = cuddZddChangeAux(zdd, cuddE(P), zvar);
|
|
if (e == NULL) {
|
|
Cudd_RecursiveDerefZdd(zdd, t);
|
|
return(NULL);
|
|
}
|
|
cuddRef(e);
|
|
res = cuddZddGetNode(zdd, P->index, t, e);
|
|
if (res == NULL) {
|
|
Cudd_RecursiveDerefZdd(zdd, t);
|
|
Cudd_RecursiveDerefZdd(zdd, e);
|
|
return(NULL);
|
|
}
|
|
cuddDeref(t);
|
|
cuddDeref(e);
|
|
}
|
|
|
|
cuddCacheInsert2(zdd, cuddZddChangeAux, P, zvar, res);
|
|
|
|
return(res);
|
|
|
|
} /* end of cuddZddChangeAux */
|
|
|
|
|
|
/**
|
|
@brief Computes the positive cofactor of a %ZDD w.r.t. a variable.
|
|
|
|
@details In terms of combinations, the result is the set of all
|
|
combinations in which the variable is asserted. cuddZddSubset1
|
|
performs the same function as Cudd_zddSubset1, but does not restart
|
|
if reordering has taken place. Therefore it can be called from
|
|
within a recursive procedure.
|
|
|
|
@return a pointer to the result if successful; NULL otherwise.
|
|
|
|
@sideeffect None
|
|
|
|
@see cuddZddSubset0 Cudd_zddSubset1
|
|
|
|
*/
|
|
DdNode *
|
|
cuddZddSubset1(
|
|
DdManager * dd,
|
|
DdNode * P,
|
|
int var)
|
|
{
|
|
DdNode *zvar, *r;
|
|
DdNode *base, *empty;
|
|
|
|
base = DD_ONE(dd);
|
|
empty = DD_ZERO(dd);
|
|
|
|
zvar = cuddUniqueInterZdd(dd, var, base, empty);
|
|
if (zvar == NULL) {
|
|
return(NULL);
|
|
} else {
|
|
cuddRef(zvar);
|
|
r = zdd_subset1_aux(dd, P, zvar);
|
|
if (r == NULL) {
|
|
Cudd_RecursiveDerefZdd(dd, zvar);
|
|
return(NULL);
|
|
}
|
|
cuddRef(r);
|
|
Cudd_RecursiveDerefZdd(dd, zvar);
|
|
}
|
|
|
|
cuddDeref(r);
|
|
return(r);
|
|
|
|
} /* end of cuddZddSubset1 */
|
|
|
|
|
|
/**
|
|
@brief Computes the negative cofactor of a %ZDD w.r.t. a variable.
|
|
|
|
@details In terms of combinations, the result is the set of all
|
|
combinations in which the variable is negated. cuddZddSubset0
|
|
performs the same function as Cudd_zddSubset0, but does not restart
|
|
if reordering has taken place. Therefore it can be called from
|
|
within a recursive procedure.
|
|
|
|
@return a pointer to the result if successful; NULL otherwise.
|
|
|
|
@sideeffect None
|
|
|
|
@see cuddZddSubset1 Cudd_zddSubset0
|
|
|
|
*/
|
|
DdNode *
|
|
cuddZddSubset0(
|
|
DdManager * dd,
|
|
DdNode * P,
|
|
int var)
|
|
{
|
|
DdNode *zvar, *r;
|
|
DdNode *base, *empty;
|
|
|
|
base = DD_ONE(dd);
|
|
empty = DD_ZERO(dd);
|
|
|
|
zvar = cuddUniqueInterZdd(dd, var, base, empty);
|
|
if (zvar == NULL) {
|
|
return(NULL);
|
|
} else {
|
|
cuddRef(zvar);
|
|
r = zdd_subset0_aux(dd, P, zvar);
|
|
if (r == NULL) {
|
|
Cudd_RecursiveDerefZdd(dd, zvar);
|
|
return(NULL);
|
|
}
|
|
cuddRef(r);
|
|
Cudd_RecursiveDerefZdd(dd, zvar);
|
|
}
|
|
|
|
cuddDeref(r);
|
|
return(r);
|
|
|
|
} /* end of cuddZddSubset0 */
|
|
|
|
|
|
/**
|
|
@brief Substitutes a variable with its complement in a %ZDD.
|
|
|
|
@details cuddZddChange performs the same function as Cudd_zddChange,
|
|
but does not restart if reordering has taken place. Therefore it can
|
|
be called from within a recursive procedure.
|
|
|
|
@return a pointer to the result if successful; NULL otherwise.
|
|
|
|
@sideeffect None
|
|
|
|
@see Cudd_zddChange
|
|
|
|
*/
|
|
DdNode *
|
|
cuddZddChange(
|
|
DdManager * dd,
|
|
DdNode * P,
|
|
int var)
|
|
{
|
|
DdNode *zvar, *res;
|
|
|
|
zvar = cuddUniqueInterZdd(dd, var, DD_ONE(dd), DD_ZERO(dd));
|
|
if (zvar == NULL) return(NULL);
|
|
cuddRef(zvar);
|
|
|
|
res = cuddZddChangeAux(dd, P, zvar);
|
|
if (res == NULL) {
|
|
Cudd_RecursiveDerefZdd(dd,zvar);
|
|
return(NULL);
|
|
}
|
|
cuddRef(res);
|
|
Cudd_RecursiveDerefZdd(dd,zvar);
|
|
cuddDeref(res);
|
|
return(res);
|
|
|
|
} /* end of cuddZddChange */
|
|
|
|
|
|
/*---------------------------------------------------------------------------*/
|
|
/* Definition of static functions */
|
|
/*---------------------------------------------------------------------------*/
|
|
|
|
|
|
/**
|
|
@brief Performs the recursive step of Cudd_zddSubset1.
|
|
|
|
@sideeffect None
|
|
|
|
*/
|
|
static DdNode *
|
|
zdd_subset1_aux(
|
|
DdManager * zdd,
|
|
DdNode * P,
|
|
DdNode * zvar)
|
|
{
|
|
int top_var, level;
|
|
DdNode *res, *t, *e;
|
|
DdNode *empty;
|
|
|
|
statLine(zdd);
|
|
empty = DD_ZERO(zdd);
|
|
|
|
/* Check cache. */
|
|
res = cuddCacheLookup2Zdd(zdd, zdd_subset1_aux, P, zvar);
|
|
if (res != NULL)
|
|
return(res);
|
|
|
|
if (cuddIsConstant(P)) {
|
|
res = empty;
|
|
cuddCacheInsert2(zdd, zdd_subset1_aux, P, zvar, res);
|
|
return(res);
|
|
}
|
|
|
|
top_var = zdd->permZ[P->index];
|
|
level = zdd->permZ[zvar->index];
|
|
|
|
if (top_var > level) {
|
|
res = empty;
|
|
} else if (top_var == level) {
|
|
res = cuddT(P);
|
|
} else {
|
|
t = zdd_subset1_aux(zdd, cuddT(P), zvar);
|
|
if (t == NULL) return(NULL);
|
|
cuddRef(t);
|
|
e = zdd_subset1_aux(zdd, cuddE(P), zvar);
|
|
if (e == NULL) {
|
|
Cudd_RecursiveDerefZdd(zdd, t);
|
|
return(NULL);
|
|
}
|
|
cuddRef(e);
|
|
res = cuddZddGetNode(zdd, P->index, t, e);
|
|
if (res == NULL) {
|
|
Cudd_RecursiveDerefZdd(zdd, t);
|
|
Cudd_RecursiveDerefZdd(zdd, e);
|
|
return(NULL);
|
|
}
|
|
cuddDeref(t);
|
|
cuddDeref(e);
|
|
}
|
|
|
|
cuddCacheInsert2(zdd, zdd_subset1_aux, P, zvar, res);
|
|
|
|
return(res);
|
|
|
|
} /* end of zdd_subset1_aux */
|
|
|
|
|
|
/**
|
|
@brief Performs the recursive step of Cudd_zddSubset0.
|
|
|
|
@sideeffect None
|
|
|
|
*/
|
|
static DdNode *
|
|
zdd_subset0_aux(
|
|
DdManager * zdd,
|
|
DdNode * P,
|
|
DdNode * zvar)
|
|
{
|
|
int top_var, level;
|
|
DdNode *res, *t, *e;
|
|
|
|
statLine(zdd);
|
|
|
|
/* Check cache. */
|
|
res = cuddCacheLookup2Zdd(zdd, zdd_subset0_aux, P, zvar);
|
|
if (res != NULL)
|
|
return(res);
|
|
|
|
if (cuddIsConstant(P)) {
|
|
res = P;
|
|
cuddCacheInsert2(zdd, zdd_subset0_aux, P, zvar, res);
|
|
return(res);
|
|
}
|
|
|
|
top_var = zdd->permZ[P->index];
|
|
level = zdd->permZ[zvar->index];
|
|
|
|
if (top_var > level) {
|
|
res = P;
|
|
}
|
|
else if (top_var == level) {
|
|
res = cuddE(P);
|
|
}
|
|
else {
|
|
t = zdd_subset0_aux(zdd, cuddT(P), zvar);
|
|
if (t == NULL) return(NULL);
|
|
cuddRef(t);
|
|
e = zdd_subset0_aux(zdd, cuddE(P), zvar);
|
|
if (e == NULL) {
|
|
Cudd_RecursiveDerefZdd(zdd, t);
|
|
return(NULL);
|
|
}
|
|
cuddRef(e);
|
|
res = cuddZddGetNode(zdd, P->index, t, e);
|
|
if (res == NULL) {
|
|
Cudd_RecursiveDerefZdd(zdd, t);
|
|
Cudd_RecursiveDerefZdd(zdd, e);
|
|
return(NULL);
|
|
}
|
|
cuddDeref(t);
|
|
cuddDeref(e);
|
|
}
|
|
|
|
cuddCacheInsert2(zdd, zdd_subset0_aux, P, zvar, res);
|
|
|
|
return(res);
|
|
|
|
} /* end of zdd_subset0_aux */
|
|
|
|
|
|
/**
|
|
@brief Replaces variables with constants if possible (part of
|
|
canonical form).
|
|
|
|
@sideeffect None
|
|
|
|
*/
|
|
static void
|
|
zddVarToConst(
|
|
DdNode * f,
|
|
DdNode ** gp,
|
|
DdNode ** hp,
|
|
DdNode * base,
|
|
DdNode * empty)
|
|
{
|
|
DdNode *g = *gp;
|
|
DdNode *h = *hp;
|
|
|
|
if (f == g) { /* ITE(F,F,H) = ITE(F,1,H) = F + H */
|
|
*gp = base;
|
|
}
|
|
|
|
if (f == h) { /* ITE(F,G,F) = ITE(F,G,0) = F * G */
|
|
*hp = empty;
|
|
}
|
|
|
|
} /* end of zddVarToConst */
|
|
|