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/**
@file
@ingroup cudd
@brief Functions that translate BDDs to ZDDs.
@author Hyong-kyoon Shin, In-Ho Moon
@copyright@parblock Copyright (c) 1995-2015, 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. @endparblock
*/
#include "util.h"
#include "cuddInt.h"
/*---------------------------------------------------------------------------*/ /* Constant declarations */ /*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/ /* Stucture declarations */ /*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/ /* Type declarations */ /*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/ /* Variable declarations */ /*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/ /* Macro declarations */ /*---------------------------------------------------------------------------*/
/** \cond */
/*---------------------------------------------------------------------------*/ /* Static function prototypes */ /*---------------------------------------------------------------------------*/
static DdNode * zddPortFromBddStep (DdManager *dd, DdNode *B, int expected); static DdNode * zddPortToBddStep (DdManager *dd, DdNode *f, int depth);
/** \endcond */
/*---------------------------------------------------------------------------*/ /* Definition of exported functions */ /*---------------------------------------------------------------------------*/
/**
@brief Converts a %BDD into a %ZDD.
@details This function assumes that there is a one-to-one correspondence between the %BDD variables and the %ZDD variables, and that the variable order is the same for both types of variables. These conditions are established if the %ZDD variables are created by one call to Cudd_zddVarsFromBddVars with multiplicity = 1.
@return a pointer to the resulting %ZDD if successful; NULL otherwise.
@sideeffect None
@see Cudd_zddVarsFromBddVars
*/ DdNode * Cudd_zddPortFromBdd( DdManager * dd, DdNode * B) { DdNode *res;
do { dd->reordered = 0; res = zddPortFromBddStep(dd,B,0); } while (dd->reordered == 1); if (dd->errorCode == CUDD_TIMEOUT_EXPIRED && dd->timeoutHandler) { dd->timeoutHandler(dd, dd->tohArg); }
return(res);
} /* end of Cudd_zddPortFromBdd */
/**
@brief Converts a %ZDD into a %BDD.
@return a pointer to the resulting %ZDD if successful; NULL otherwise.
@sideeffect None
@see Cudd_zddPortFromBdd
*/ DdNode * Cudd_zddPortToBdd( DdManager * dd, DdNode * f) { DdNode *res;
do { dd->reordered = 0; res = zddPortToBddStep(dd,f,0); } while (dd->reordered == 1); if (dd->errorCode == CUDD_TIMEOUT_EXPIRED && dd->timeoutHandler) { dd->timeoutHandler(dd, dd->tohArg); }
return(res);
} /* end of Cudd_zddPortToBdd */
/*---------------------------------------------------------------------------*/ /* Definition of internal functions */ /*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/ /* Definition of static functions */ /*---------------------------------------------------------------------------*/
/**
@brief Performs the recursive step of Cudd_zddPortFromBdd.
@sideeffect None
*/ static DdNode * zddPortFromBddStep( DdManager * dd, DdNode * B, int expected) { DdNode *res, *prevZdd, *t, *e; DdNode *Breg, *Bt, *Be; int id; int level;
statLine(dd); /* Terminal cases. */ if (B == Cudd_Not(DD_ONE(dd))) return(DD_ZERO(dd)); if (B == DD_ONE(dd)) { if (expected >= dd->sizeZ) { return(DD_ONE(dd)); } else { return(dd->univ[expected]); } }
Breg = Cudd_Regular(B);
/* Computed table look-up. */ res = cuddCacheLookup1Zdd(dd,Cudd_zddPortFromBdd,B); if (res != NULL) { level = cuddI(dd,Breg->index); /* Adding DC vars. */ if (expected < level) { /* Add suppressed variables. */ cuddRef(res); for (level--; level >= expected; level--) { prevZdd = res; id = dd->invperm[level]; res = cuddZddGetNode(dd, id, prevZdd, prevZdd); if (res == NULL) { Cudd_RecursiveDerefZdd(dd, prevZdd); return(NULL); } cuddRef(res); Cudd_RecursiveDerefZdd(dd, prevZdd); } cuddDeref(res); } return(res); } /* end of cache look-up */
if (Cudd_IsComplement(B)) { Bt = Cudd_Not(cuddT(Breg)); Be = Cudd_Not(cuddE(Breg)); } else { Bt = cuddT(Breg); Be = cuddE(Breg); }
id = (int) Breg->index; level = cuddI(dd,id); t = zddPortFromBddStep(dd, Bt, level+1); if (t == NULL) return(NULL); cuddRef(t); e = zddPortFromBddStep(dd, Be, level+1); if (e == NULL) { Cudd_RecursiveDerefZdd(dd, t); return(NULL); } cuddRef(e); res = cuddZddGetNode(dd, id, t, e); if (res == NULL) { Cudd_RecursiveDerefZdd(dd, t); Cudd_RecursiveDerefZdd(dd, e); return(NULL); } cuddRef(res); Cudd_RecursiveDerefZdd(dd, t); Cudd_RecursiveDerefZdd(dd, e);
cuddCacheInsert1(dd,Cudd_zddPortFromBdd,B,res);
for (level--; level >= expected; level--) { prevZdd = res; id = dd->invperm[level]; res = cuddZddGetNode(dd, id, prevZdd, prevZdd); if (res == NULL) { Cudd_RecursiveDerefZdd(dd, prevZdd); return(NULL); } cuddRef(res); Cudd_RecursiveDerefZdd(dd, prevZdd); }
cuddDeref(res); return(res);
} /* end of zddPortFromBddStep */
/**
@brief Performs the recursive step of Cudd_zddPortToBdd.
@sideeffect None
*/ static DdNode * zddPortToBddStep( DdManager * dd /* manager */, DdNode * f /* %ZDD to be converted */, int depth /* recursion depth */) { DdNode *one, *zero, *T, *E, *res, *var; int index; int level;
statLine(dd); one = DD_ONE(dd); zero = DD_ZERO(dd); if (f == zero) return(Cudd_Not(one));
if (depth == dd->sizeZ) return(one);
index = dd->invpermZ[depth]; level = cuddIZ(dd,f->index); var = cuddUniqueInter(dd,index,one,Cudd_Not(one)); if (var == NULL) return(NULL); cuddRef(var);
if (level > depth) { E = zddPortToBddStep(dd,f,depth+1); if (E == NULL) { Cudd_RecursiveDeref(dd,var); return(NULL); } cuddRef(E); res = cuddBddIteRecur(dd,var,Cudd_Not(one),E); if (res == NULL) { Cudd_RecursiveDeref(dd,var); Cudd_RecursiveDeref(dd,E); return(NULL); } cuddRef(res); Cudd_RecursiveDeref(dd,var); Cudd_RecursiveDeref(dd,E); cuddDeref(res); return(res); }
res = cuddCacheLookup1(dd,Cudd_zddPortToBdd,f); if (res != NULL) { Cudd_RecursiveDeref(dd,var); return(res); }
T = zddPortToBddStep(dd,cuddT(f),depth+1); if (T == NULL) { Cudd_RecursiveDeref(dd,var); return(NULL); } cuddRef(T); E = zddPortToBddStep(dd,cuddE(f),depth+1); if (E == NULL) { Cudd_RecursiveDeref(dd,var); Cudd_RecursiveDeref(dd,T); return(NULL); } cuddRef(E);
res = cuddBddIteRecur(dd,var,T,E); if (res == NULL) { Cudd_RecursiveDeref(dd,var); Cudd_RecursiveDeref(dd,T); Cudd_RecursiveDeref(dd,E); return(NULL); } cuddRef(res); Cudd_RecursiveDeref(dd,var); Cudd_RecursiveDeref(dd,T); Cudd_RecursiveDeref(dd,E); cuddDeref(res);
cuddCacheInsert1(dd,Cudd_zddPortToBdd,f,res);
return(res);
} /* end of zddPortToBddStep */
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