cuddAddIte.c File Reference

#include "CUDD/util.h"
#include "CUDD/cuddInt.h"

Go to the source code of this file.

Functions
static void	addVarToConst (DdNode *f, DdNode **gp, DdNode **hp, DdNode *one, DdNode *zero)
DdNode *	Cudd_addIte (DdManager *dd, DdNode *f, DdNode *g, DdNode *h)
DdNode *	Cudd_addIteConstant (DdManager *dd, DdNode *f, DdNode *g, DdNode *h)
DdNode *	Cudd_addEvalConst (DdManager *dd, DdNode *f, DdNode *g)
DdNode *	Cudd_addCmpl (DdManager *dd, DdNode *f)
int	Cudd_addLeq (DdManager *dd, DdNode *f, DdNode *g)
DdNode *	cuddAddIteRecur (DdManager *dd, DdNode *f, DdNode *g, DdNode *h)
DdNode *	cuddAddCmplRecur (DdManager *dd, DdNode *f)

Variables
static char rcsid []	DD_UNUSED = "$Id: cuddAddIte.c,v 1.16 2012/02/05 01:07:18 fabio Exp $"

Function Documentation

addVarToConst()

static void addVarToConst ( DdNode *  f, DdNode **  gp, DdNode **  hp, DdNode *  one, DdNode *  zero  )

static

AutomaticStart

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

Synopsis [Replaces variables with constants if possible (part of canonical form).]

Description []

SideEffects [None]

Definition at line 621 of file cuddAddIte.c.

{
    DdNode *g = *gp;
    DdNode *h = *hp;

    if (f == g) { /* ITE(F,F,H) = ITE(F,1,H) = F + H */
    *gp = one;
    }

    if (f == h) { /* ITE(F,G,F) = ITE(F,G,0) = F * G */
    *hp = zero;
    }

} /* end of addVarToConst */

Cudd_addCmpl()

DdNode* Cudd_addCmpl	(	DdManager *	dd,
		DdNode *	f
	)

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

Synopsis [Computes the complement of an ADD a la C language.]

Description [Computes the complement of an ADD a la C language: The complement of 0 is 1 and the complement of everything else is 0. Returns a pointer to the resulting ADD if successful; NULL otherwise.]

SideEffects [None]

SeeAlso [Cudd_addNegate]

Definition at line 343 of file cuddAddIte.c.

{
    DdNode *res;

    do {
    dd->reordered = 0;
    res = cuddAddCmplRecur(dd,f);
    } while (dd->reordered == 1);
    return(res);

} /* end of Cudd_addCmpl */

Cudd_addEvalConst()

DdNode* Cudd_addEvalConst	(	DdManager *	dd,
		DdNode *	f,
		DdNode *	g
	)

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

Synopsis [Checks whether ADD g is constant whenever ADD f is 1.]

Description [Checks whether ADD g is constant whenever ADD f is 1. f must be a 0-1 ADD. Returns a pointer to the resulting ADD (which may or may not be constant) or DD_NON_CONSTANT. If f is identically 0, the check is assumed to be successful, and the background value is returned. No new nodes are created.]

SideEffects [None]

SeeAlso [Cudd_addIteConstant Cudd_addLeq]

Definition at line 256 of file cuddAddIte.c.

{
    DdNode *zero;
    DdNode *Fv,*Fnv,*Gv,*Gnv,*r,*t,*e;
    unsigned int topf,topg;

#ifdef DD_DEBUG
    assert(!Cudd_IsComplement(f));
#endif

    statLine(dd);
    /* Terminal cases. */
    if (f == DD_ONE(dd) || cuddIsConstant(g)) {
        return(g);
    }
    if (f == (zero = DD_ZERO(dd))) {
        return(dd->background);
    }

#ifdef DD_DEBUG
    assert(!cuddIsConstant(f));
#endif
    /* From now on, f and g are known not to be constants. */

    topf = cuddI(dd,f->index);
    topg = cuddI(dd,g->index);

    /* Check cache. */
    r = cuddConstantLookup(dd,DD_ADD_EVAL_CONST_TAG,f,g,g);
    if (r != NULL) {
        return(r);
    }

    /* Compute cofactors. */
    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;
    }
    
    /* Recursive step. */
    if (Fv != zero) {
    t = Cudd_addEvalConst(dd,Fv,Gv);
    if (t == DD_NON_CONSTANT || !cuddIsConstant(t)) {
        cuddCacheInsert2(dd, Cudd_addEvalConst, f, g, DD_NON_CONSTANT);
        return(DD_NON_CONSTANT);
    }
    if (Fnv != zero) {
        e = Cudd_addEvalConst(dd,Fnv,Gnv);
        if (e == DD_NON_CONSTANT || !cuddIsConstant(e) || t != e) {
        cuddCacheInsert2(dd, Cudd_addEvalConst, f, g, DD_NON_CONSTANT);
        return(DD_NON_CONSTANT);
        }
    }
    cuddCacheInsert2(dd,Cudd_addEvalConst,f,g,t);
    return(t);
    } else { /* Fnv must be != zero */
    e = Cudd_addEvalConst(dd,Fnv,Gnv);
    cuddCacheInsert2(dd, Cudd_addEvalConst, f, g, e);
    return(e);
    }

} /* end of Cudd_addEvalConst */

Cudd_addIte()

DdNode* Cudd_addIte	(	DdManager *	dd,
		DdNode *	f,
		DdNode *	g,
		DdNode *	h
	)

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

Synopsis [Implements ITE(f,g,h).]

Description [Implements ITE(f,g,h). This procedure assumes that f is a 0-1 ADD. Returns a pointer to the resulting ADD if successful; NULL otherwise.]

SideEffects [None]

SeeAlso [Cudd_bddIte Cudd_addIteConstant Cudd_addApply]

Definition at line 125 of file cuddAddIte.c.

{
    DdNode *res;

    do {
    dd->reordered = 0;
    res = cuddAddIteRecur(dd,f,g,h);
    } while (dd->reordered == 1);
    return(res);

} /* end of Cudd_addIte */

Cudd_addIteConstant()

DdNode* Cudd_addIteConstant	(	DdManager *	dd,
		DdNode *	f,
		DdNode *	g,
		DdNode *	h
	)

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

Synopsis [Implements ITEconstant for ADDs.]

Description [Implements ITEconstant for ADDs. f must be a 0-1 ADD. Returns a pointer to the resulting ADD (which may or may not be constant) or DD_NON_CONSTANT. No new nodes are created. This function can be used, for instance, to check that g has a constant value (specified by h) whenever f is 1. If the constant value is unknown, then one should use Cudd_addEvalConst.]

SideEffects [None]

SeeAlso [Cudd_addIte Cudd_addEvalConst Cudd_bddIteConstant]

Definition at line 159 of file cuddAddIte.c.

{
    DdNode *one,*zero;
    DdNode *Fv,*Fnv,*Gv,*Gnv,*Hv,*Hnv,*r,*t,*e;
    unsigned int topf,topg,toph,v;

    statLine(dd);
    /* Trivial cases. */
    if (f == (one = DD_ONE(dd))) {  /* ITE(1,G,H) = G */
        return(g);
    }
    if (f == (zero = DD_ZERO(dd))) {    /* ITE(0,G,H) = H */
        return(h);
    }

    /* From now on, f is known not to be a constant. */
    addVarToConst(f,&g,&h,one,zero);

    /* Check remaining one variable cases. */
    if (g == h) {           /* ITE(F,G,G) = G */
        return(g);
    }
    if (cuddIsConstant(g) && cuddIsConstant(h)) {
        return(DD_NON_CONSTANT);
    }

    topf = cuddI(dd,f->index);
    topg = cuddI(dd,g->index);
    toph = cuddI(dd,h->index);
    v = ddMin(topg,toph);

    /* ITE(F,G,H) = (x,G,H) (non constant) if F = (x,1,0), x < top(G,H). */
    if (topf < v && cuddIsConstant(cuddT(f)) && cuddIsConstant(cuddE(f))) {
    return(DD_NON_CONSTANT);
    }

    /* Check cache. */
    r = cuddConstantLookup(dd,DD_ADD_ITE_CONSTANT_TAG,f,g,h);
    if (r != NULL) {
        return(r);
    }

    /* Compute cofactors. */
    if (topf <= v) {
    v = ddMin(topf,v);  /* v = top_var(F,G,H) */
        Fv = cuddT(f); Fnv = cuddE(f);
    } else {
        Fv = Fnv = f;
    }
    if (topg == v) {
        Gv = cuddT(g); Gnv = cuddE(g);
    } else {
        Gv = Gnv = g;
    }
    if (toph == v) {
        Hv = cuddT(h); Hnv = cuddE(h);
    } else {
        Hv = Hnv = h;
    }
    
    /* Recursive step. */
    t = Cudd_addIteConstant(dd,Fv,Gv,Hv);
    if (t == DD_NON_CONSTANT || !cuddIsConstant(t)) {
    cuddCacheInsert(dd, DD_ADD_ITE_CONSTANT_TAG, f, g, h, DD_NON_CONSTANT);
    return(DD_NON_CONSTANT);
    }
    e = Cudd_addIteConstant(dd,Fnv,Gnv,Hnv);
    if (e == DD_NON_CONSTANT || !cuddIsConstant(e) || t != e) {
    cuddCacheInsert(dd, DD_ADD_ITE_CONSTANT_TAG, f, g, h, DD_NON_CONSTANT);
    return(DD_NON_CONSTANT);
    }
    cuddCacheInsert(dd, DD_ADD_ITE_CONSTANT_TAG, f, g, h, t);
    return(t);

} /* end of Cudd_addIteConstant */

Cudd_addLeq()

int Cudd_addLeq	(	DdManager *	dd,
		DdNode *	f,
		DdNode *	g
	)

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

Synopsis [Determines whether f is less than or equal to g.]

Description [Returns 1 if f is less than or equal to g; 0 otherwise. No new nodes are created. This procedure works for arbitrary ADDs. For 0-1 ADDs Cudd_addEvalConst is more efficient.]

SideEffects [None]

SeeAlso [Cudd_addIteConstant Cudd_addEvalConst Cudd_bddLeq]

Definition at line 372 of file cuddAddIte.c.

{
    DdNode *tmp, *fv, *fvn, *gv, *gvn;
    unsigned int topf, topg, res;

    /* Terminal cases. */
    if (f == g) return(1);

    statLine(dd);
    if (cuddIsConstant(f)) {
    if (cuddIsConstant(g)) return(cuddV(f) <= cuddV(g));
    if (f == DD_MINUS_INFINITY(dd)) return(1);
    if (f == DD_PLUS_INFINITY(dd)) return(0); /* since f != g */
    }
    if (g == DD_PLUS_INFINITY(dd)) return(1);
    if (g == DD_MINUS_INFINITY(dd)) return(0); /* since f != g */

    /* Check cache. */
    tmp = cuddCacheLookup2(dd,(DD_CTFP)Cudd_addLeq,f,g);
    if (tmp != NULL) {
    return(tmp == DD_ONE(dd));
    }

    /* Compute cofactors. One of f and g is not constant. */
    topf = cuddI(dd,f->index);
    topg = cuddI(dd,g->index);
    if (topf <= topg) {
    fv = cuddT(f); fvn = cuddE(f);
    } else {
    fv = fvn = f;
    }
    if (topg <= topf) {
    gv = cuddT(g); gvn = cuddE(g);
    } else {
    gv = gvn = g;
    }

    res = Cudd_addLeq(dd,fvn,gvn) && Cudd_addLeq(dd,fv,gv);

    /* Store result in cache and return. */
    cuddCacheInsert2(dd,(DD_CTFP) Cudd_addLeq,f,g,
             Cudd_NotCond(DD_ONE(dd),res==0));
    return(res);

} /* end of Cudd_addLeq */

cuddAddCmplRecur()

DdNode* cuddAddCmplRecur	(	DdManager *	dd,
		DdNode *	f
	)

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

Synopsis [Performs the recursive step of Cudd_addCmpl.]

Description [Performs the recursive step of Cudd_addCmpl. Returns a pointer to the resulting ADD if successful; NULL otherwise.]

SideEffects [None]

SeeAlso [Cudd_addCmpl]

Definition at line 558 of file cuddAddIte.c.

{
    DdNode *one,*zero;
    DdNode *r,*Fv,*Fnv,*t,*e;

    statLine(dd);
    one = DD_ONE(dd);
    zero = DD_ZERO(dd); 

    if (cuddIsConstant(f)) {
        if (f == zero) {
        return(one);
    } else {
        return(zero);
    }
    }
    r = cuddCacheLookup1(dd,Cudd_addCmpl,f);
    if (r != NULL) {
    return(r);
    }
    Fv = cuddT(f);
    Fnv = cuddE(f);
    t = cuddAddCmplRecur(dd,Fv);
    if (t == NULL) return(NULL);
    cuddRef(t);
    e = cuddAddCmplRecur(dd,Fnv);
    if (e == NULL) {
    Cudd_RecursiveDeref(dd,t);
    return(NULL);
    }
    cuddRef(e);
    r = (t == e) ? t : cuddUniqueInter(dd,(int)f->index,t,e);
    if (r == NULL) {
    Cudd_RecursiveDeref(dd, t);
    Cudd_RecursiveDeref(dd, e);
    return(NULL);
    }
    cuddDeref(t);
    cuddDeref(e);
    cuddCacheInsert1(dd,Cudd_addCmpl,f,r);
    return(r);

} /* end of cuddAddCmplRecur */

cuddAddIteRecur()

DdNode* cuddAddIteRecur	(	DdManager *	dd,
		DdNode *	f,
		DdNode *	g,
		DdNode *	h
	)

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

Synopsis [Implements the recursive step of Cudd_addIte(f,g,h).]

Description [Implements the recursive step of Cudd_addIte(f,g,h). Returns a pointer to the resulting ADD if successful; NULL otherwise.]

SideEffects [None]

SeeAlso [Cudd_addIte]

Definition at line 441 of file cuddAddIte.c.

{
    DdNode *one,*zero;
    DdNode *r,*Fv,*Fnv,*Gv,*Gnv,*Hv,*Hnv,*t,*e;
    unsigned int topf,topg,toph,v;
    int index;

    statLine(dd);
    /* Trivial cases. */

    /* One variable cases. */
    if (f == (one = DD_ONE(dd))) {  /* ITE(1,G,H) = G */
        return(g);
    }
    if (f == (zero = DD_ZERO(dd))) {    /* ITE(0,G,H) = H */
        return(h);
    }

    /* From now on, f is known to not be a constant. */
    addVarToConst(f,&g,&h,one,zero);

    /* Check remaining one variable cases. */
    if (g == h) {           /* ITE(F,G,G) = G */
        return(g);
    }

    if (g == one) {         /* ITE(F,1,0) = F */
        if (h == zero) return(f);
    }

    topf = cuddI(dd,f->index);
    topg = cuddI(dd,g->index);
    toph = cuddI(dd,h->index);
    v = ddMin(topg,toph);

    /* A shortcut: ITE(F,G,H) = (x,G,H) if F=(x,1,0), x < top(G,H). */
    if (topf < v && cuddT(f) == one && cuddE(f) == zero) {
    r = cuddUniqueInter(dd,(int)f->index,g,h);
    return(r);
    }
    if (topf < v && cuddT(f) == zero && cuddE(f) == one) {
    r = cuddUniqueInter(dd,(int)f->index,h,g);
    return(r);
    }

    /* Check cache. */
    r = cuddCacheLookup(dd,DD_ADD_ITE_TAG,f,g,h);
    if (r != NULL) {
        return(r);
    }

    /* Compute cofactors. */
    if (topf <= v) {
    v = ddMin(topf,v);  /* v = top_var(F,G,H) */
    index = f->index;
        Fv = cuddT(f); Fnv = cuddE(f);
    } else {
        Fv = Fnv = f;
    }
    if (topg == v) {
    index = g->index;
        Gv = cuddT(g); Gnv = cuddE(g);
    } else {
        Gv = Gnv = g;
    }
    if (toph == v) {
    index = h->index;
        Hv = cuddT(h); Hnv = cuddE(h);
    } else {
        Hv = Hnv = h;
    }
    
    /* Recursive step. */
    t = cuddAddIteRecur(dd,Fv,Gv,Hv);
    if (t == NULL) return(NULL);
    cuddRef(t);

    e = cuddAddIteRecur(dd,Fnv,Gnv,Hnv);
    if (e == NULL) {
    Cudd_RecursiveDeref(dd,t);
    return(NULL);
    }
    cuddRef(e);

    r = (t == e) ? t : cuddUniqueInter(dd,index,t,e);
    if (r == NULL) {
    Cudd_RecursiveDeref(dd,t);
    Cudd_RecursiveDeref(dd,e);
    return(NULL);
    }
    cuddDeref(t);
    cuddDeref(e);

    cuddCacheInsert(dd,DD_ADD_ITE_TAG,f,g,h,r);

    return(r);

} /* end of cuddAddIteRecur */

Variable Documentation

DD_UNUSED

char rcsid [] DD_UNUSED = "$Id: cuddAddIte.c,v 1.16 2012/02/05 01:07:18 fabio Exp $"

static

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

FileName [cuddAddIte.c]

PackageName [cudd]

Synopsis [ADD ITE function and satellites.]

Description [External procedures included in this module:

• Cudd_addIte()
• Cudd_addIteConstant()
• Cudd_addEvalConst()
• Cudd_addCmpl()
• Cudd_addLeq()

Internal procedures included in this module:

• cuddAddIteRecur()
• cuddAddCmplRecur()

Static procedures included in this module:

• addVarToConst()

]

Author [Fabio Somenzi]

Copyright [Copyright (c) 1995-2012, 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 86 of file cuddAddIte.c.