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

Data Structures
struct	hashEntry

Typedefs
typedef ABC_NAMESPACE_IMPL_START struct hashEntry	HashEntry

Functions
static double	bddCorrelationAux (DdManager dd, DdNode f, DdNode g, st__table table)

static double	bddCorrelationWeightsAux (DdManager dd, DdNode f, DdNode g, double prob, st__table *table)

static int	CorrelCompare (const char key1, const char key2)

static int	CorrelHash (const char *key, int modulus)

static enum st__retval	CorrelCleanUp (char key, char value, char *arg)

double	Cudd_bddCorrelation (DdManager manager, DdNode f, DdNode *g)

double	Cudd_bddCorrelationWeights (DdManager manager, DdNode f, DdNode g, double prob)

Variables
static char rcsid[]	DD_UNUSED = "$Id: cuddBddCorr.c,v 1.14 2004/08/13 18:04:46 fabio Exp $"

Typedef Documentation

typedef ABC_NAMESPACE_IMPL_START struct hashEntry HashEntry

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

FileName [cuddBddCorr.c]

PackageName [cudd]

Synopsis [Correlation between BDDs.]

Description [External procedures included in this module:

Static procedures included in this module:

]

Author [Fabio Somenzi]

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.]

Function Documentation

static double bddCorrelationAux	(	DdManager *	dd,
		DdNode *	f,
		DdNode *	g,
		st__table *	table
	)

static

AutomaticStart

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

Synopsis [Performs the recursive step of Cudd_bddCorrelation.]

Description [Performs the recursive step of Cudd_bddCorrelation. Returns the fraction of minterms in the ON-set of the EXNOR of f and g.]

SideEffects [None]

SeeAlso [bddCorrelationWeightsAux]

Definition at line 237 of file cuddBddCorr.c.

 {
     DdNode      *Fv, *Fnv, *G, *Gv, *Gnv;
     double      min, *pmin, min1, min2, *dummy;
     HashEntry   *entry;
     unsigned int topF, topG;
 
     statLine(dd);
 #ifdef CORREL_STATS
     num_calls++;
 #endif
 
     /* Terminal cases: only work for BDDs. */
     if (f == g) return(1.0);
     if (f == Cudd_Not(g)) return(0.0);
 
     /* Standardize call using the following properties:
     **     (f EXNOR g)   = (g EXNOR f)
     **     (f' EXNOR g') = (f EXNOR g).
     */
     if (cuddF2L(f) > cuddF2L(g)) {
         DdNode *tmp = f;
         f = g; g = tmp;
     }
     if (Cudd_IsComplement(f)) {
         f = Cudd_Not(f);
         g = Cudd_Not(g);
     }
     /* From now on, f is regular. */
     
     entry = ABC_ALLOC(HashEntry,1);
     if (entry == NULL) {
         dd->errorCode = CUDD_MEMORY_OUT;
         return(CUDD_OUT_OF_MEM);
     }
     entry->f = f; entry->g = g;
 
     /* We do not use the fact that
     ** correlation(f,g') = 1 - correlation(f,g)
     ** to minimize the risk of cancellation.
     */
     if ( st__lookup(table, (const char *)entry, (char **)&dummy)) {
         min = *dummy;
         ABC_FREE(entry);
         return(min);
     }
 
     G = Cudd_Regular(g);
     topF = cuddI(dd,f->index); topG = cuddI(dd,G->index);
     if (topF <= topG) { Fv = cuddT(f); Fnv = cuddE(f); } else { Fv = Fnv = f; }
     if (topG <= topF) { Gv = cuddT(G); Gnv = cuddE(G); } else { Gv = Gnv = G; }
 
     if (g != G) {
         Gv = Cudd_Not(Gv);
         Gnv = Cudd_Not(Gnv);
     }
 
     min1 = bddCorrelationAux(dd, Fv, Gv, table) / 2.0;
     if (min1 == (double)CUDD_OUT_OF_MEM) {
         ABC_FREE(entry);
         return(CUDD_OUT_OF_MEM);
     }
     min2 = bddCorrelationAux(dd, Fnv, Gnv, table) / 2.0; 
     if (min2 == (double)CUDD_OUT_OF_MEM) {
         ABC_FREE(entry);
         return(CUDD_OUT_OF_MEM);
     }
     min = (min1+min2);
     
     pmin = ABC_ALLOC(double,1);
     if (pmin == NULL) {
         dd->errorCode = CUDD_MEMORY_OUT;
         return((double)CUDD_OUT_OF_MEM);
     }
     *pmin = min;
 
     if ( st__insert(table,(char *)entry, (char *)pmin) == st__OUT_OF_MEM) {
         ABC_FREE(entry);
         ABC_FREE(pmin);
         return((double)CUDD_OUT_OF_MEM);
     }
     return(min);
 
 } /* end of bddCorrelationAux */

static double bddCorrelationWeightsAux	(	DdManager *	dd,
		DdNode *	f,
		DdNode *	g,
		double *	prob,
		st__table *	table
	)

static

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

Synopsis [Performs the recursive step of Cudd_bddCorrelationWeigths.]

Description []

SideEffects [None]

SeeAlso [bddCorrelationAux]

Definition at line 339 of file cuddBddCorr.c.

 {
     DdNode      *Fv, *Fnv, *G, *Gv, *Gnv;
     double      min, *pmin, min1, min2, *dummy;
     HashEntry   *entry;
     int         topF, topG, index;
 
     statLine(dd);
 #ifdef CORREL_STATS
     num_calls++;
 #endif
 
     /* Terminal cases: only work for BDDs. */
     if (f == g) return(1.0);
     if (f == Cudd_Not(g)) return(0.0);
 
     /* Standardize call using the following properties:
     **     (f EXNOR g)   = (g EXNOR f)
     **     (f' EXNOR g') = (f EXNOR g).
     */
     if (cuddF2L(f) > cuddF2L(g)) {
         DdNode *tmp = f;
         f = g; g = tmp;
     }
     if (Cudd_IsComplement(f)) {
         f = Cudd_Not(f);
         g = Cudd_Not(g);
     }
     /* From now on, f is regular. */
     
     entry = ABC_ALLOC(HashEntry,1);
     if (entry == NULL) {
         dd->errorCode = CUDD_MEMORY_OUT;
         return((double)CUDD_OUT_OF_MEM);
     }
     entry->f = f; entry->g = g;
 
     /* We do not use the fact that
     ** correlation(f,g') = 1 - correlation(f,g)
     ** to minimize the risk of cancellation.
     */
     if ( st__lookup(table, (const char *)entry, (char **)&dummy)) {
         min = *dummy;
         ABC_FREE(entry);
         return(min);
     }
 
     G = Cudd_Regular(g);
     topF = cuddI(dd,f->index); topG = cuddI(dd,G->index);
     if (topF <= topG) {
         Fv = cuddT(f); Fnv = cuddE(f);
         index = f->index;
     } else {
         Fv = Fnv = f;
         index = G->index;
     }
     if (topG <= topF) { Gv = cuddT(G); Gnv = cuddE(G); } else { Gv = Gnv = G; }
 
     if (g != G) {
         Gv = Cudd_Not(Gv);
         Gnv = Cudd_Not(Gnv);
     }
 
     min1 = bddCorrelationWeightsAux(dd, Fv, Gv, prob, table) * prob[index];
     if (min1 == (double)CUDD_OUT_OF_MEM) {
         ABC_FREE(entry);
         return((double)CUDD_OUT_OF_MEM);
     }
     min2 = bddCorrelationWeightsAux(dd, Fnv, Gnv, prob, table) * (1.0 - prob[index]); 
     if (min2 == (double)CUDD_OUT_OF_MEM) {
         ABC_FREE(entry);
         return((double)CUDD_OUT_OF_MEM);
     }
     min = (min1+min2);
     
     pmin = ABC_ALLOC(double,1);
     if (pmin == NULL) {
         dd->errorCode = CUDD_MEMORY_OUT;
         return((double)CUDD_OUT_OF_MEM);
     }
     *pmin = min;
 
     if ( st__insert(table,(char *)entry, (char *)pmin) == st__OUT_OF_MEM) {
         ABC_FREE(entry);
         ABC_FREE(pmin);
         return((double)CUDD_OUT_OF_MEM);
     }
     return(min);
 
 } /* end of bddCorrelationWeightsAux */

static enum st__retval CorrelCleanUp	(	char *	key,
		char *	value,
		char *	arg
	)

static

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

Synopsis [Frees memory associated with hash table.]

Description [Frees memory associated with hash table. Returns st__CONTINUE.]

SideEffects [None]

Definition at line 504 of file cuddBddCorr.c.

 {
     double      *d;
     HashEntry *entry;
 
     entry = (HashEntry *) key;
     ABC_FREE(entry);
     d = (double *)value;
     ABC_FREE(d);
     return st__CONTINUE;
 
 } /* end of CorrelCleanUp */

static int CorrelCompare	(	const char *	key1,
		const char *	key2
	)

static

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

Synopsis [Compares two hash table entries.]

Description [Compares two hash table entries. Returns 0 if they are identical; 1 otherwise.]

SideEffects [None]

Definition at line 447 of file cuddBddCorr.c.

 {
     HashEntry *entry1;
     HashEntry *entry2;
 
     entry1 = (HashEntry *) key1;
     entry2 = (HashEntry *) key2;
     if (entry1->f != entry2->f || entry1->g != entry2->g) return(1);
 
     return(0);
 
 } /* end of CorrelCompare */

static int CorrelHash	(	const char *	key,
		int	modulus
	)

static

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

Synopsis [Hashes a hash table entry.]

Description [Hashes a hash table entry. It is patterned after st__strhash. Returns a value between 0 and modulus.]

SideEffects [None]

Definition at line 474 of file cuddBddCorr.c.

 {
     HashEntry *entry;
     int val = 0;
 
     entry = (HashEntry *) key;
 #if SIZEOF_VOID_P == 8 && SIZEOF_INT == 4
     val = ((int) ((long)entry->f))*997 + ((int) ((long)entry->g));
 #else
     val = ((int) entry->f)*997 + ((int) entry->g);
 #endif
 
     return ((val < 0) ? -val : val) % modulus;
 
 } /* end of CorrelHash */

double Cudd_bddCorrelation	(	DdManager *	manager,
		DdNode *	f,
		DdNode *	g
	)

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

Synopsis [Computes the correlation of f and g.]

Description [Computes the correlation of f and g. If f == g, their correlation is 1. If f == g', their correlation is 0. Returns the fraction of minterms in the ON-set of the EXNOR of f and g. If it runs out of memory, returns (double)CUDD_OUT_OF_MEM.]

SideEffects [None]

SeeAlso [Cudd_bddCorrelationWeights]

Definition at line 147 of file cuddBddCorr.c.

 {
 
     st__table    *table;
     double      correlation;
 
 #ifdef CORREL_STATS
     num_calls = 0;
 #endif
 
     table = st__init_table(CorrelCompare,CorrelHash);
     if (table == NULL) return((double)CUDD_OUT_OF_MEM);
     correlation = bddCorrelationAux(manager,f,g,table);
     st__foreach(table, CorrelCleanUp, NIL(char));
     st__free_table(table);
     return(correlation);
 
 } /* end of Cudd_bddCorrelation */

double Cudd_bddCorrelationWeights	(	DdManager *	manager,
		DdNode *	f,
		DdNode *	g,
		double *	prob
	)

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

Synopsis [Computes the correlation of f and g for given input probabilities.]

Description [Computes the correlation of f and g for given input probabilities. On input, prob[i] is supposed to contain the probability of the i-th input variable to be 1. If f == g, their correlation is 1. If f == g', their correlation is 0. Returns the probability that f and g have the same value. If it runs out of memory, returns (double)CUDD_OUT_OF_MEM. The correlation of f and the constant one gives the probability of f.]

SideEffects [None]

SeeAlso [Cudd_bddCorrelation]

Definition at line 189 of file cuddBddCorr.c.

 {
 
     st__table    *table;
     double      correlation;
 
 #ifdef CORREL_STATS
     num_calls = 0;
 #endif
 
     table = st__init_table(CorrelCompare,CorrelHash);
     if (table == NULL) return((double)CUDD_OUT_OF_MEM);
     correlation = bddCorrelationWeightsAux(manager,f,g,prob,table);
     st__foreach(table, CorrelCleanUp, NIL(char));
     st__free_table(table);
     return(correlation);
 
 } /* end of Cudd_bddCorrelationWeights */

Variable Documentation

char rcsid [] DD_UNUSED = "$Id: cuddBddCorr.c,v 1.14 2004/08/13 18:04:46 fabio Exp $"

static

Definition at line 93 of file cuddBddCorr.c.

Data Structures

Typedefs

Functions

Variables

Typedef Documentation

Function Documentation

Variable Documentation