/**CFile***********************************************************************
FileName [cuddAddFind.c]
PackageName [cudd]
Synopsis [Functions to find maximum and minimum in an ADD and to
extract the i-th bit.]
Description [External procedures included in this module:
<ul>
<li> Cudd_addFindMax()
<li> Cudd_addFindMin()
<li> Cudd_addIthBit()
</ul>
Static functions included in this module:
<ul>
<li> addDoIthBit()
</ul>]
Author [Fabio Somenzi]
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.]
******************************************************************************/
#include "misc/util/util_hack.h"
#include "cuddInt.h"
ABC_NAMESPACE_IMPL_START
/*---------------------------------------------------------------------------*/
/* Constant declarations */
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
/* Stucture declarations */
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
/* Type declarations */
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
/* Variable declarations */
/*---------------------------------------------------------------------------*/
#ifndef lint
static char rcsid[] DD_UNUSED = "$Id: cuddAddFind.c,v 1.8 2004/08/13 18:04:45 fabio Exp $";
#endif
/*---------------------------------------------------------------------------*/
/* Macro declarations */
/*---------------------------------------------------------------------------*/
/**AutomaticStart*************************************************************/
/*---------------------------------------------------------------------------*/
/* Static function prototypes */
/*---------------------------------------------------------------------------*/
static DdNode * addDoIthBit (DdManager *dd, DdNode *f, DdNode *index);
/**AutomaticEnd***************************************************************/
/*---------------------------------------------------------------------------*/
/* Definition of exported functions */
/*---------------------------------------------------------------------------*/
/**Function********************************************************************
Synopsis [Finds the maximum discriminant of f.]
Description [Returns a pointer to a constant ADD.]
SideEffects [None]
******************************************************************************/
DdNode *
Cudd_addFindMax(
DdManager * dd,
DdNode * f)
{
DdNode *t, *e, *res;
statLine(dd);
if (cuddIsConstant(f)) {
return(f);
}
res = cuddCacheLookup1(dd,Cudd_addFindMax,f);
if (res != NULL) {
return(res);
}
t = Cudd_addFindMax(dd,cuddT(f));
if (t == DD_PLUS_INFINITY(dd)) return(t);
e = Cudd_addFindMax(dd,cuddE(f));
res = (cuddV(t) >= cuddV(e)) ? t : e;
cuddCacheInsert1(dd,Cudd_addFindMax,f,res);
return(res);
} /* end of Cudd_addFindMax */
/**Function********************************************************************
Synopsis [Finds the minimum discriminant of f.]
Description [Returns a pointer to a constant ADD.]
SideEffects [None]
******************************************************************************/
DdNode *
Cudd_addFindMin(
DdManager * dd,
DdNode * f)
{
DdNode *t, *e, *res;
statLine(dd);
if (cuddIsConstant(f)) {
return(f);
}
res = cuddCacheLookup1(dd,Cudd_addFindMin,f);
if (res != NULL) {
return(res);
}
t = Cudd_addFindMin(dd,cuddT(f));
if (t == DD_MINUS_INFINITY(dd)) return(t);
e = Cudd_addFindMin(dd,cuddE(f));
res = (cuddV(t) <= cuddV(e)) ? t : e;
cuddCacheInsert1(dd,Cudd_addFindMin,f,res);
return(res);
} /* end of Cudd_addFindMin */
/**Function********************************************************************
Synopsis [Extracts the i-th bit from an ADD.]
Description [Produces an ADD from another ADD by replacing all
discriminants whose i-th bit is equal to 1 with 1, and all other
discriminants with 0. The i-th bit refers to the integer
representation of the leaf value. If the value is has a fractional
part, it is ignored. Repeated calls to this procedure allow one to
transform an integer-valued ADD into an array of ADDs, one for each
bit of the leaf values. Returns a pointer to the resulting ADD if
successful; NULL otherwise.]
SideEffects [None]
SeeAlso [Cudd_addBddIthBit]
******************************************************************************/
DdNode *
Cudd_addIthBit(
DdManager * dd,
DdNode * f,
int bit)
{
DdNode *res;
DdNode *index;
/* Use a constant node to remember the bit, so that we can use the
** global cache.
*/
index = cuddUniqueConst(dd,(CUDD_VALUE_TYPE) bit);
if (index == NULL) return(NULL);
cuddRef(index);
do {
dd->reordered = 0;
res = addDoIthBit(dd, f, index);
} while (dd->reordered == 1);
if (res == NULL) {
Cudd_RecursiveDeref(dd, index);
return(NULL);
}
cuddRef(res);
Cudd_RecursiveDeref(dd, index);
cuddDeref(res);
return(res);
} /* end of Cudd_addIthBit */
/*---------------------------------------------------------------------------*/
/* Definition of internal functions */
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
/* Definition of static functions */
/*---------------------------------------------------------------------------*/
/**Function********************************************************************
Synopsis [Performs the recursive step for Cudd_addIthBit.]
Description [Performs the recursive step for Cudd_addIthBit.
Returns a pointer to the BDD if successful; NULL otherwise.]
SideEffects [None]
SeeAlso []
******************************************************************************/
static DdNode *
addDoIthBit(
DdManager * dd,
DdNode * f,
DdNode * index)
{
DdNode *res, *T, *E;
DdNode *fv, *fvn;
int mask, value;
int v;
statLine(dd);
/* Check terminal case. */
if (cuddIsConstant(f)) {
mask = 1 << ((int) cuddV(index));
value = (int) cuddV(f);
return((value & mask) == 0 ? DD_ZERO(dd) : DD_ONE(dd));
}
/* Check cache. */
res = cuddCacheLookup2(dd,addDoIthBit,f,index);
if (res != NULL) return(res);
/* Recursive step. */
v = f->index;
fv = cuddT(f); fvn = cuddE(f);
T = addDoIthBit(dd,fv,index);
if (T == NULL) return(NULL);
cuddRef(T);
E = addDoIthBit(dd,fvn,index);
if (E == NULL) {
Cudd_RecursiveDeref(dd, T);
return(NULL);
}
cuddRef(E);
res = (T == E) ? T : cuddUniqueInter(dd,v,T,E);
if (res == NULL) {
Cudd_RecursiveDeref(dd, T);
Cudd_RecursiveDeref(dd, E);
return(NULL);
}
cuddDeref(T);
cuddDeref(E);
/* Store result. */
cuddCacheInsert2(dd,addDoIthBit,f,index,res);
return(res);
} /* end of addDoIthBit */
ABC_NAMESPACE_IMPL_END