src/cuBdd/cuddSign.c File Reference

#include "util.h"
#include "cuddInt.h"

Include dependency graph for cuddSign.c:

Go to the source code of this file.

Functions
static double *	ddCofMintermAux (DdManager *dd, DdNode *node, st_table *table)
double *	Cudd_CofMinterm (DdManager *dd, DdNode *node)
Variables
static char rcsid[]	DD_UNUSED = "$Id: cuddSign.c,v 1.22 2009/02/20 02:14:58 fabio Exp $"
static int	size

---

Function Documentation

double* Cudd_CofMinterm	(	DdManager *	dd,
		DdNode *	node
	)

AutomaticEnd Function********************************************************************

Synopsis [Computes the fraction of minterms in the on-set of all the positive cofactors of a BDD or ADD.]

Description [Computes the fraction of minterms in the on-set of all the positive cofactors of DD. Returns the pointer to an array of doubles if successful; NULL otherwise. The array has as many positions as there are BDD variables in the manager plus one. The last position of the array contains the fraction of the minterms in the ON-set of the function represented by the BDD or ADD. The other positions of the array hold the variable signatures.]

SideEffects [None]

Definition at line 127 of file cuddSign.c.

{
    st_table    *table;
    double      *values;
    double      *result = NULL;
    int         i, firstLevel;

#ifdef DD_STATS
    long startTime;
    startTime = util_cpu_time();
    num_calls = 0;
    table_mem = sizeof(st_table);
#endif

    table = st_init_table(st_ptrcmp, st_ptrhash);
    if (table == NULL) {
        (void) fprintf(dd->err,
                       "out-of-memory, couldn't measure DD cofactors.\n");
        dd->errorCode = CUDD_MEMORY_OUT;
        return(NULL);
    }
    size = dd->size;
    values = ddCofMintermAux(dd, node, table);
    if (values != NULL) {
        result = ALLOC(double,size + 1);
        if (result != NULL) {
#ifdef DD_STATS
            table_mem += (size + 1) * sizeof(double);
#endif
            if (Cudd_IsConstant(node))
                firstLevel = 1;
            else
                firstLevel = cuddI(dd,Cudd_Regular(node)->index);
            for (i = 0; i < size; i++) {
                if (i >= cuddI(dd,Cudd_Regular(node)->index)) {
                    result[dd->invperm[i]] = values[i - firstLevel];
                } else {
                    result[dd->invperm[i]] = values[size - firstLevel];
                }
            }
            result[size] = values[size - firstLevel];
        } else {
            dd->errorCode = CUDD_MEMORY_OUT;
        }
    }

#ifdef DD_STATS
    table_mem += table->num_bins * sizeof(st_table_entry *);
#endif
    if (Cudd_Regular(node)->ref == 1) FREE(values);
    st_foreach(table, cuddStCountfree, NULL);
    st_free_table(table);
#ifdef DD_STATS
    (void) fprintf(dd->out,"Number of calls: %d\tTable memory: %d bytes\n",
                  num_calls, table_mem);
    (void) fprintf(dd->out,"Time to compute measures: %s\n",
                  util_print_time(util_cpu_time() - startTime));
#endif
    if (result == NULL) {
        (void) fprintf(dd->out,
                       "out-of-memory, couldn't measure DD cofactors.\n");
        dd->errorCode = CUDD_MEMORY_OUT;
    }
    return(result);

} /* end of Cudd_CofMinterm */

static double * ddCofMintermAux	(	DdManager *	dd,
		DdNode *	node,
		st_table *	table
	)			[static]

AutomaticStart

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

Synopsis [Recursive Step for Cudd_CofMinterm function.]

Description [Traverses the DD node and computes the fraction of minterms in the on-set of all positive cofactors simultaneously. It allocates an array with two more entries than there are variables below the one labeling the node. One extra entry (the first in the array) is for the variable labeling the node. The other entry (the last one in the array) holds the fraction of minterms of the function rooted at node. Each other entry holds the value for one cofactor. The array is put in a symbol table, to avoid repeated computation, and its address is returned by the procedure, for use by the caller. Returns a pointer to the array of cofactor measures.]

SideEffects [None]

SeeAlso []

Definition at line 228 of file cuddSign.c.

{
    DdNode      *N;             /* regular version of node */
    DdNode      *Nv, *Nnv;
    double      *values;
    double      *valuesT, *valuesE;
    int         i;
    int         localSize, localSizeT, localSizeE;
    double      vT, vE;

    statLine(dd);
#ifdef DD_STATS
    num_calls++;
#endif

    if (st_lookup(table, node, &values)) {
        return(values);
    }

    N = Cudd_Regular(node);
    if (cuddIsConstant(N)) {
        localSize = 1;
    } else {
        localSize = size - cuddI(dd,N->index) + 1;
    }
    values = ALLOC(double, localSize);
    if (values == NULL) {
        dd->errorCode = CUDD_MEMORY_OUT;
        return(NULL);
    }

    if (cuddIsConstant(N)) {
        if (node == DD_ZERO(dd) || node == Cudd_Not(DD_ONE(dd))) {
            values[0] = 0.0;
        } else {
            values[0] = 1.0;
        }
    } else {
        Nv = Cudd_NotCond(cuddT(N),N!=node);
        Nnv = Cudd_NotCond(cuddE(N),N!=node);

        valuesT = ddCofMintermAux(dd, Nv, table);
        if (valuesT == NULL) return(NULL);
        valuesE = ddCofMintermAux(dd, Nnv, table);
        if (valuesE == NULL) return(NULL);

        if (Cudd_IsConstant(Nv)) {
            localSizeT = 1;
        } else {
            localSizeT = size - cuddI(dd,Cudd_Regular(Nv)->index) + 1;
        }
        if (Cudd_IsConstant(Nnv)) {
            localSizeE = 1;
        } else {
            localSizeE = size - cuddI(dd,Cudd_Regular(Nnv)->index) + 1;
        }
        values[0] = valuesT[localSizeT - 1];
        for (i = 1; i < localSize; i++) {
            if (i >= cuddI(dd,Cudd_Regular(Nv)->index) - cuddI(dd,N->index)) {
                vT = valuesT[i - cuddI(dd,Cudd_Regular(Nv)->index) +
                            cuddI(dd,N->index)];
            } else {
                vT = valuesT[localSizeT - 1];
            }
            if (i >= cuddI(dd,Cudd_Regular(Nnv)->index) - cuddI(dd,N->index)) {
                vE = valuesE[i - cuddI(dd,Cudd_Regular(Nnv)->index) +
                            cuddI(dd,N->index)];
            } else {
                vE = valuesE[localSizeE - 1];
            }
            values[i] = (vT + vE) / 2.0;
        }
        if (Cudd_Regular(Nv)->ref == 1) FREE(valuesT);
        if (Cudd_Regular(Nnv)->ref == 1) FREE(valuesE);
    }

    if (N->ref > 1) {
        if (st_add_direct(table, (char *) node, (char *) values) == ST_OUT_OF_MEM) {
            FREE(values);
            return(NULL);
        }
#ifdef DD_STATS
        table_mem += localSize * sizeof(double) + sizeof(st_table_entry);
#endif
    }
    return(values);

} /* end of ddCofMintermAux */

---

Variable Documentation

char rcsid [] DD_UNUSED = "$Id: cuddSign.c,v 1.22 2009/02/20 02:14:58 fabio Exp $" [static]

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

FileName [cuddSign.c]

PackageName [cudd]

Synopsis [Computation of signatures.]

Description [External procedures included in this module:

• Cudd_CofMinterm();

Static procedures included in this module:

• ddCofMintermAux()

]

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.]

Definition at line 79 of file cuddSign.c.

int size [static]

Definition at line 82 of file cuddSign.c.