/**Function********************************************************************
Synopsis [Performs the recursive step of Cudd_Cofactor.]
Description [Performs the recursive step of Cudd_Cofactor. Returns a
pointer to the cofactor if successful; NULL otherwise.]
SideEffects [None]
SeeAlso [Cudd_Cofactor]
******************************************************************************/
DdNode *
cuddCofactorRecur(
DdManager * dd,
DdNode * f,
DdNode * g)
{
DdNode *one,*zero,*F,*G,*g1,*g0,*f1,*f0,*t,*e,*r;
unsigned int topf,topg;
int comple;
statLine(dd);
F = Cudd_Regular(f);
if (cuddIsConstant(F)) return(f);
one = DD_ONE(dd);
/* The invariant g != 0 is true on entry to this procedure and is
** recursively maintained by it. Therefore it suffices to test g
** against one to make sure it is not constant.
*/
if (g == one) return(f);
/* From now on, f and g are known not to be constants. */
comple = f != F;
r = cuddCacheLookup2(dd,Cudd_Cofactor,F,g);
if (r != NULL) {
return(Cudd_NotCond(r,comple));
}
topf = dd->perm[F->index];
G = Cudd_Regular(g);
topg = dd->perm[G->index];
/* We take the cofactors of F because we are going to rely on
** the fact that the cofactors of the complement are the complements
** of the cofactors to better utilize the cache. Variable comple
** remembers whether we have to complement the result or not.
*/
if (topf <= topg) {
f1 = cuddT(F); f0 = cuddE(F);
} else {
f1 = f0 = F;
}
if (topg <= topf) {
g1 = cuddT(G); g0 = cuddE(G);
if (g != G) { g1 = Cudd_Not(g1); g0 = Cudd_Not(g0); }
} else {
g1 = g0 = g;
}
zero = Cudd_Not(one);
if (topf >= topg) {
if (g0 == zero || g0 == DD_ZERO(dd)) {
r = cuddCofactorRecur(dd, f1, g1);
} else if (g1 == zero || g1 == DD_ZERO(dd)) {
r = cuddCofactorRecur(dd, f0, g0);
} else {
(void) fprintf(dd->out,
"Cudd_Cofactor: Invalid restriction 2\n");
dd->errorCode = CUDD_INVALID_ARG;
return(NULL);
}
if (r == NULL) return(NULL);
} else /* if (topf < topg) */ {
t = cuddCofactorRecur(dd, f1, g);
if (t == NULL) return(NULL);
cuddRef(t);
e = cuddCofactorRecur(dd, f0, g);
if (e == NULL) {
Cudd_RecursiveDeref(dd, t);
return(NULL);
}
cuddRef(e);
if (t == e) {
r = t;
} else if (Cudd_IsComplement(t)) {
r = cuddUniqueInter(dd,(int)F->index,Cudd_Not(t),Cudd_Not(e));
if (r != NULL)
r = Cudd_Not(r);
} else {
r = cuddUniqueInter(dd,(int)F->index,t,e);
}
if (r == NULL) {
Cudd_RecursiveDeref(dd ,e);
Cudd_RecursiveDeref(dd ,t);
return(NULL);
}
cuddDeref(t);
cuddDeref(e);
}
cuddCacheInsert2(dd,Cudd_Cofactor,F,g,r);
return(Cudd_NotCond(r,comple));
} /* end of cuddCofactorRecur */
/**Function********************************************************************
Synopsis [Performs the recursive step for Cudd_addBddBooleanMap.]
Description [Performs the recursive step for Cudd_addBddBooleanMap.
Returns a pointer to the BDD if successful; NULL otherwise.]
SideEffects [None]
SeeAlso [addBddDoStrictThreshold]
******************************************************************************/
static DdNode *
addBddBooleanMap(
DdManager * dd,
DdNode * f)
{
DdNode *res, *T, *E;
DdNode *fv, *fvn;
int v;
statLine(dd);
/* Check terminal case. */
if (cuddIsConstant(f)) {
if ((f != DD_TRUE(dd)) && (f != DD_FALSE(dd))) {
(void)fprintf(dd->err, "Error: Can only convert Add with FALSE or TRUE leaves to Bdd.");
return(NULL);
}
return(Cudd_NotCond(DD_TRUE(dd), f == DD_FALSE(dd)));
}
/* Check cache. */
res = cuddCacheLookup1(dd,addBddBooleanMap,f);
if (res != NULL) return(res);
/* Recursive step. */
v = f->index;
fv = cuddT(f); fvn = cuddE(f);
T = addBddBooleanMap(dd,fv);
if (T == NULL) return(NULL);
cuddRef(T);
E = addBddBooleanMap(dd,fvn);
if (E == NULL) {
Cudd_RecursiveDeref(dd, T);
return(NULL);
}
cuddRef(E);
if (Cudd_IsComplement(T)) {
res = (T == E) ? Cudd_Not(T) : cuddUniqueInter(dd,v,Cudd_Not(T),Cudd_Not(E));
if (res == NULL) {
Cudd_RecursiveDeref(dd, T);
Cudd_RecursiveDeref(dd, E);
return(NULL);
}
res = Cudd_Not(res);
} else {
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. */
cuddCacheInsert1(dd,addBddBooleanMap,f,res);
return(res);
} /* end of addBddBooleanMap */
/**Function********************************************************************
Synopsis [Performs the recursive step for Cudd_addBddIthBit.]
Description [Performs the recursive step for Cudd_addBddIthBit.
Returns a pointer to the BDD if successful; NULL otherwise.]
SideEffects [None]
SeeAlso []
******************************************************************************/
static DdNode *
addBddDoIthBit(
DdManager * dd,
DdNode * f,
DdNode * index)
{
DdNode *res, *T, *E;
DdNode *fv, *fvn;
/* NuSMV: add begin */
ptrint mask, value;
/* WAS: long mask, value; */
/* NuSMV: add end */
int v;
statLine(dd);
/* Check terminal case. */
if (cuddIsConstant(f)) {
/* NuSMV: add begin */
mask = 1 << ((ptrint) cuddV(index));
value = (ptrint) cuddV(f);
/* WAS: mask = 1 << ((long) cuddV(index));
value = (long) cuddV(f); */
/* NuSMV: add end */
return(Cudd_NotCond(DD_TRUE(dd),(value & mask) == 0));
}
/* Check cache. */
res = cuddCacheLookup2(dd,addBddDoIthBit,f,index);
if (res != NULL) return(res);
/* Recursive step. */
v = f->index;
fv = cuddT(f); fvn = cuddE(f);
T = addBddDoIthBit(dd,fv,index);
if (T == NULL) return(NULL);
cuddRef(T);
E = addBddDoIthBit(dd,fvn,index);
if (E == NULL) {
Cudd_RecursiveDeref(dd, T);
return(NULL);
}
cuddRef(E);
if (Cudd_IsComplement(T)) {
res = (T == E) ? Cudd_Not(T) : cuddUniqueInter(dd,v,Cudd_Not(T),Cudd_Not(E));
if (res == NULL) {
Cudd_RecursiveDeref(dd, T);
Cudd_RecursiveDeref(dd, E);
return(NULL);
}
res = Cudd_Not(res);
} else {
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,addBddDoIthBit,f,index,res);
return(res);
} /* end of addBddDoIthBit */
/**Function********************************************************************
Synopsis [Performs the recursive step of Cudd_bddTransfer.]
Description [Performs the recursive step of Cudd_bddTransfer.
Returns a pointer to the result if successful; NULL otherwise.]
SideEffects [None]
SeeAlso [cuddBddTransfer]
******************************************************************************/
static DdNode *
cuddBddTransferRecur(
DdManager * ddS,
DdManager * ddD,
DdNode * f,
st_table * table)
{
DdNode *ft, *fe, *t, *e, *var, *res;
DdNode *one, *zero;
int index;
int comple = 0;
statLine(ddD);
one = DD_TRUE(ddD);
comple = Cudd_IsComplement(f);
/* Trivial cases. */
if (Cudd_IsConstant(f)) return(Cudd_NotCond(one, comple));
/* Make canonical to increase the utilization of the cache. */
f = Cudd_NotCond(f,comple);
/* Now f is a regular pointer to a non-constant node. */
/* Check the cache. */
if(st_lookup(table, f, &res))
return(Cudd_NotCond(res,comple));
/* Recursive step. */
index = f->index;
ft = cuddT(f); fe = cuddE(f);
t = cuddBddTransferRecur(ddS, ddD, ft, table);
if (t == NULL) {
return(NULL);
}
cuddRef(t);
e = cuddBddTransferRecur(ddS, ddD, fe, table);
if (e == NULL) {
Cudd_RecursiveDeref(ddD, t);
return(NULL);
}
cuddRef(e);
zero = Cudd_Not(one);
var = cuddUniqueInter(ddD,index,one,zero);
if (var == NULL) {
Cudd_RecursiveDeref(ddD, t);
Cudd_RecursiveDeref(ddD, e);
return(NULL);
}
res = cuddBddIteRecur(ddD,var,t,e);
if (res == NULL) {
Cudd_RecursiveDeref(ddD, t);
Cudd_RecursiveDeref(ddD, e);
return(NULL);
}
cuddRef(res);
Cudd_RecursiveDeref(ddD, t);
Cudd_RecursiveDeref(ddD, e);
if (st_add_direct(table, (char *) f, (char *) res) == ST_OUT_OF_MEM) {
Cudd_RecursiveDeref(ddD, res);
return(NULL);
}
return(Cudd_NotCond(res,comple));
} /* end of cuddBddTransferRecur */
/**Function********************************************************************
Synopsis [Performs the recursive step for Cudd_addBddPattern.]
Description [Performs the recursive step for Cudd_addBddPattern. Returns a
pointer to the resulting BDD if successful; NULL otherwise.]
SideEffects [None]
SeeAlso []
******************************************************************************/
DdNode *
cuddAddBddDoPattern(
DdManager * dd,
DdNode * f)
{
DdNode *res, *T, *E;
DdNode *fv, *fvn;
int v;
/* NuSMV: begin add */
abort(); /* NOT USED BY NUSMV */
/* NuSMV: begin end */
statLine(dd);
/* Check terminal case. */
if (cuddIsConstant(f)) {
return(Cudd_NotCond(DD_TRUE(dd),f == DD_FALSE(dd)));
}
/* Check cache. */
res = cuddCacheLookup1(dd,Cudd_addBddPattern,f);
if (res != NULL) return(res);
/* Recursive step. */
v = f->index;
fv = cuddT(f); fvn = cuddE(f);
T = cuddAddBddDoPattern(dd,fv);
if (T == NULL) return(NULL);
cuddRef(T);
E = cuddAddBddDoPattern(dd,fvn);
if (E == NULL) {
Cudd_RecursiveDeref(dd, T);
return(NULL);
}
cuddRef(E);
if (Cudd_IsComplement(T)) {
res = (T == E) ? Cudd_Not(T) : cuddUniqueInter(dd,v,Cudd_Not(T),Cudd_Not(E));
if (res == NULL) {
Cudd_RecursiveDeref(dd, T);
Cudd_RecursiveDeref(dd, E);
return(NULL);
}
res = Cudd_Not(res);
} else {
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. */
cuddCacheInsert1(dd,Cudd_addBddPattern,f,res);
return(res);
} /* end of cuddAddBddDoPattern */
/**Function********************************************************************
Synopsis [Performs the recursive step for Cudd_BddTo01Add.]
Description [Performs the recursive step for Cudd_BddTo01Add. Returns a
pointer to the resulting ADD if successful; NULL otherwise.]
SideEffects [None]
SeeAlso []
******************************************************************************/
static DdNode *
ddBddTo01AddRecur(
DdManager * dd,
DdNode * B)
{
DdNode *res, *res1, *T, *E, *Bt, *Be;
int complement = 0;
statLine(dd);
if (B == DD_TRUE(dd)) {
return DD_ONE(dd);
} else if (B == Cudd_Not(DD_TRUE(dd))) {
return DD_ZERO(dd);
}
/* Check visited table */
res = cuddCacheLookup1(dd,ddBddTo01AddRecur,B);
if (res != NULL) return(res);
if (Cudd_IsComplement(B)) {
complement = 1;
Bt = cuddT(Cudd_Regular(B));
Be = cuddE(Cudd_Regular(B));
} else {
Bt = cuddT(B);
Be = cuddE(B);
}
T = ddBddTo01AddRecur(dd, Bt);
if (T == NULL) return(NULL);
cuddRef(T);
E = ddBddTo01AddRecur(dd, Be);
if (E == NULL) {
Cudd_RecursiveDeref(dd, T);
return(NULL);
}
cuddRef(E);
/* No need to check for T == E, because it is guaranteed not to happen. */
res = cuddUniqueInter(dd, (int) Cudd_Regular(B)->index, T, E);
if (res == NULL) {
Cudd_RecursiveDeref(dd ,T);
Cudd_RecursiveDeref(dd ,E);
return(NULL);
}
cuddDeref(T);
cuddDeref(E);
if (complement) {
cuddRef(res);
res1 = cuddAddCmpl01Recur(dd, res);
if (res1 == NULL) {
Cudd_RecursiveDeref(dd, res);
return(NULL);
}
cuddRef(res1);
Cudd_RecursiveDeref(dd, res);
res = res1;
cuddDeref(res);
}
/* Store result. */
cuddCacheInsert1(dd,ddBddTo01AddRecur,B,res);
return(res);
} /* end of ddBddTo01AddRecur */
/**Function********************************************************************
Synopsis [Performs the recursive step of Cudd_bddCompose.]
Description [Performs the recursive step of Cudd_bddCompose.
Exploits the fact that the composition of f' with g
produces the complement of the composition of f with g to better
utilize the cache. Returns the composed BDD if successful; NULL
otherwise.]
SideEffects [None]
SeeAlso [Cudd_bddCompose]
******************************************************************************/
DdNode *
cuddBddComposeRecur(
DdManager * dd,
DdNode * f,
DdNode * g,
DdNode * proj)
{
DdNode *F, *G, *f1, *f0, *g1, *g0, *r, *t, *e;
unsigned int v, topf, topg, topindex;
int comple;
statLine(dd);
v = dd->perm[proj->index];
F = Cudd_Regular(f);
topf = cuddI(dd,F->index);
/* Terminal case. Subsumes the test for constant f. */
if (topf > v) return(f);
/* We solve the problem for a regular pointer, and then complement
** the result if the pointer was originally complemented.
*/
comple = Cudd_IsComplement(f);
/* Check cache. */
r = cuddCacheLookup(dd,DD_BDD_COMPOSE_RECUR_TAG,F,g,proj);
if (r != NULL) {
return(Cudd_NotCond(r,comple));
}
if (topf == v) {
/* Compose. */
f1 = cuddT(F);
f0 = cuddE(F);
r = cuddBddIteRecur(dd, g, f1, f0);
if (r == NULL) return(NULL);
} else {
/* Compute cofactors of f and g. Remember the index of the top
** variable.
*/
G = Cudd_Regular(g);
topg = cuddI(dd,G->index);
if (topf > topg) {
topindex = G->index;
f1 = f0 = F;
} else {
topindex = F->index;
f1 = cuddT(F);
f0 = cuddE(F);
}
if (topg > topf) {
g1 = g0 = g;
} else {
g1 = cuddT(G);
g0 = cuddE(G);
if (g != G) {
g1 = Cudd_Not(g1);
g0 = Cudd_Not(g0);
}
}
/* Recursive step. */
t = cuddBddComposeRecur(dd, f1, g1, proj);
if (t == NULL) return(NULL);
cuddRef(t);
e = cuddBddComposeRecur(dd, f0, g0, proj);
if (e == NULL) {
Cudd_IterDerefBdd(dd, t);
return(NULL);
}
cuddRef(e);
r = cuddBddIteRecur(dd, dd->vars[topindex], t, e);
if (r == NULL) {
Cudd_IterDerefBdd(dd, t);
Cudd_IterDerefBdd(dd, e);
return(NULL);
}
cuddRef(r);
Cudd_IterDerefBdd(dd, t); /* t & e not necessarily part of r */
Cudd_IterDerefBdd(dd, e);
cuddDeref(r);
}
cuddCacheInsert(dd,DD_BDD_COMPOSE_RECUR_TAG,F,g,proj,r);
return(Cudd_NotCond(r,comple));
} /* end of cuddBddComposeRecur */
/**
@brief Takes the exclusive OR of two BDDs and simultaneously abstracts the
variables in cube.
@details The variables are existentially abstracted.
@return a pointer to the result is successful; NULL otherwise.
@sideeffect None
@see Cudd_bddAndAbstract
*/
DdNode *
cuddBddXorExistAbstractRecur(
DdManager * manager,
DdNode * f,
DdNode * g,
DdNode * cube)
{
DdNode *F, *fv, *fnv, *G, *gv, *gnv;
DdNode *one, *zero, *r, *t, *e, *Cube;
int topf, topg, topcube, top;
unsigned int index;
statLine(manager);
one = DD_ONE(manager);
zero = Cudd_Not(one);
/* Terminal cases. */
if (f == g) {
return(zero);
}
if (f == Cudd_Not(g)) {
return(one);
}
if (cube == one) {
return(cuddBddXorRecur(manager, f, g));
}
if (f == one) {
return(cuddBddExistAbstractRecur(manager, Cudd_Not(g), cube));
}
if (g == one) {
return(cuddBddExistAbstractRecur(manager, Cudd_Not(f), cube));
}
if (f == zero) {
return(cuddBddExistAbstractRecur(manager, g, cube));
}
if (g == zero) {
return(cuddBddExistAbstractRecur(manager, f, cube));
}
/* At this point f, g, and cube are not constant. */
if (f > g) { /* Try to increase cache efficiency. */
DdNode *tmp = f;
f = g;
g = tmp;
}
/* Check cache. */
r = cuddCacheLookup(manager, DD_BDD_XOR_EXIST_ABSTRACT_TAG, f, g, cube);
if (r != NULL) {
return(r);
}
checkWhetherToGiveUp(manager);
/* Here we can skip the use of cuddI, because the operands are known
** to be non-constant.
*/
F = Cudd_Regular(f);
topf = manager->perm[F->index];
G = Cudd_Regular(g);
topg = manager->perm[G->index];
top = ddMin(topf, topg);
topcube = manager->perm[cube->index];
if (topcube < top) {
return(cuddBddXorExistAbstractRecur(manager, f, g, cuddT(cube)));
}
/* Now, topcube >= top. */
if (topf == top) {
index = F->index;
fv = cuddT(F);
fnv = cuddE(F);
if (Cudd_IsComplement(f)) {
fv = Cudd_Not(fv);
fnv = Cudd_Not(fnv);
}
} else {
index = G->index;
fv = fnv = f;
}
if (topg == top) {
gv = cuddT(G);
gnv = cuddE(G);
if (Cudd_IsComplement(g)) {
gv = Cudd_Not(gv);
gnv = Cudd_Not(gnv);
}
} else {
gv = gnv = g;
}
if (topcube == top) {
Cube = cuddT(cube);
} else {
Cube = cube;
}
t = cuddBddXorExistAbstractRecur(manager, fv, gv, Cube);
if (t == NULL) return(NULL);
/* Special case: 1 OR anything = 1. Hence, no need to compute
** the else branch if t is 1.
*/
if (t == one && topcube == top) {
cuddCacheInsert(manager, DD_BDD_XOR_EXIST_ABSTRACT_TAG, f, g, cube, one);
return(one);
}
cuddRef(t);
e = cuddBddXorExistAbstractRecur(manager, fnv, gnv, Cube);
if (e == NULL) {
Cudd_IterDerefBdd(manager, t);
return(NULL);
}
cuddRef(e);
if (topcube == top) { /* abstract */
r = cuddBddAndRecur(manager, Cudd_Not(t), Cudd_Not(e));
if (r == NULL) {
Cudd_IterDerefBdd(manager, t);
Cudd_IterDerefBdd(manager, e);
return(NULL);
}
r = Cudd_Not(r);
cuddRef(r);
Cudd_IterDerefBdd(manager, t);
Cudd_IterDerefBdd(manager, e);
cuddDeref(r);
} else if (t == e) {
r = t;
cuddDeref(t);
cuddDeref(e);
} else {
if (Cudd_IsComplement(t)) {
r = cuddUniqueInter(manager,(int)index,Cudd_Not(t),Cudd_Not(e));
if (r == NULL) {
Cudd_IterDerefBdd(manager, t);
Cudd_IterDerefBdd(manager, e);
return(NULL);
}
r = Cudd_Not(r);
} else {
r = cuddUniqueInter(manager,(int)index,t,e);
if (r == NULL) {
Cudd_IterDerefBdd(manager, t);
Cudd_IterDerefBdd(manager, e);
return(NULL);
}
}
cuddDeref(e);
cuddDeref(t);
}
cuddCacheInsert(manager, DD_BDD_XOR_EXIST_ABSTRACT_TAG, f, g, cube, r);
return (r);
} /* end of cuddBddXorExistAbstractRecur */
/**Function********************************************************************
Synopsis [Implements the recursive step of Cudd_SplitSet.]
Description [Implements the recursive step of Cudd_SplitSet. The
procedure recursively traverses the BDD and checks to see if any
node satisfies the minterm requirements as specified by 'n'. At any
node X, n is compared to the number of minterms in the onset of X's
children. If either of the child nodes have exactly n minterms, then
that node is returned; else, if n is greater than the onset of one
of the child nodes, that node is retained and the difference in the
number of minterms is extracted from the other child. In case n
minterms can be extracted from constant 1, the algorithm returns the
result with at most log(n) nodes.]
SideEffects [The array 'varSeen' is updated at every recursive call
to set the variables traversed by the procedure.]
SeeAlso []
******************************************************************************/
DdNode*
cuddSplitSetRecur(
DdManager * manager,
st_table * mtable,
int * varSeen,
DdNode * p,
double n,
double max,
int index)
{
DdNode *one, *zero, *N, *Nv;
DdNode *Nnv, *q, *r, *v;
DdNode *result;
double *dummy, numT, numE;
int variable, positive;
statLine(manager);
one = DD_ONE(manager);
zero = Cudd_Not(one);
/* If p is constant, extract n minterms from constant 1. The procedure by
** construction guarantees that minterms will not be extracted from
** constant 0.
*/
if (Cudd_IsConstant(p)) {
q = selectMintermsFromUniverse(manager,varSeen,n);
return(q);
}
N = Cudd_Regular(p);
/* Set variable as seen. */
variable = N->index;
varSeen[manager->invperm[variable]] = -1;
Nv = cuddT(N);
Nnv = cuddE(N);
if (Cudd_IsComplement(p)) {
Nv = Cudd_Not(Nv);
Nnv = Cudd_Not(Nnv);
}
/* If both the children of 'p' are constants, extract n minterms from a
** constant node.
*/
if (Cudd_IsConstant(Nv) && Cudd_IsConstant(Nnv)) {
q = selectMintermsFromUniverse(manager,varSeen,n);
if (q == NULL) {
return(NULL);
}
cuddRef(q);
r = cuddBddAndRecur(manager,p,q);
if (r == NULL) {
Cudd_RecursiveDeref(manager,q);
return(NULL);
}
cuddRef(r);
Cudd_RecursiveDeref(manager,q);
cuddDeref(r);
return(r);
}
/* Lookup the # of minterms in the onset of the node from the table. */
if (!Cudd_IsConstant(Nv)) {
if (!st_lookup(mtable, (const char *)Nv, (char **)&dummy)) return(NULL);
numT = *dummy/(2*(1<<index));
} else if (Nv == one) {
numT = max/(2*(1<<index));
} else {
numT = 0;
}
if (!Cudd_IsConstant(Nnv)) {
if (!st_lookup(mtable, (const char *)Nnv, (char **)&dummy)) return(NULL);
numE = *dummy/(2*(1<<index));
} else if (Nnv == one) {
numE = max/(2*(1<<index));
} else {
numE = 0;
}
v = cuddUniqueInter(manager,variable,one,zero);
cuddRef(v);
/* If perfect match. */
if (numT == n) {
q = cuddBddAndRecur(manager,v,Nv);
if (q == NULL) {
Cudd_RecursiveDeref(manager,v);
return(NULL);
}
cuddRef(q);
Cudd_RecursiveDeref(manager,v);
cuddDeref(q);
return(q);
}
if (numE == n) {
q = cuddBddAndRecur(manager,Cudd_Not(v),Nnv);
if (q == NULL) {
Cudd_RecursiveDeref(manager,v);
return(NULL);
}
cuddRef(q);
Cudd_RecursiveDeref(manager,v);
cuddDeref(q);
return(q);
}
/* If n is greater than numT, extract the difference from the ELSE child
** and retain the function represented by the THEN branch.
*/
if (numT < n) {
q = cuddSplitSetRecur(manager,mtable,varSeen,
Nnv,(n-numT),max,index+1);
if (q == NULL) {
Cudd_RecursiveDeref(manager,v);
return(NULL);
}
cuddRef(q);
r = cuddBddIteRecur(manager,v,Nv,q);
if (r == NULL) {
Cudd_RecursiveDeref(manager,q);
Cudd_RecursiveDeref(manager,v);
return(NULL);
}
cuddRef(r);
Cudd_RecursiveDeref(manager,q);
Cudd_RecursiveDeref(manager,v);
cuddDeref(r);
return(r);
}
/* If n is greater than numE, extract the difference from the THEN child
** and retain the function represented by the ELSE branch.
*/
if (numE < n) {
q = cuddSplitSetRecur(manager,mtable,varSeen,
Nv, (n-numE),max,index+1);
if (q == NULL) {
Cudd_RecursiveDeref(manager,v);
return(NULL);
}
cuddRef(q);
r = cuddBddIteRecur(manager,v,q,Nnv);
if (r == NULL) {
Cudd_RecursiveDeref(manager,q);
Cudd_RecursiveDeref(manager,v);
return(NULL);
}
cuddRef(r);
Cudd_RecursiveDeref(manager,q);
Cudd_RecursiveDeref(manager,v);
cuddDeref(r);
return(r);
}
/* None of the above cases; (n < numT and n < numE) and either of
** the Nv, Nnv or both are not constants. If possible extract the
** required minterms the constant branch.
*/
if (Cudd_IsConstant(Nv) && !Cudd_IsConstant(Nnv)) {
q = selectMintermsFromUniverse(manager,varSeen,n);
if (q == NULL) {
Cudd_RecursiveDeref(manager,v);
return(NULL);
}
cuddRef(q);
result = cuddBddAndRecur(manager,v,q);
if (result == NULL) {
Cudd_RecursiveDeref(manager,q);
Cudd_RecursiveDeref(manager,v);
return(NULL);
}
cuddRef(result);
Cudd_RecursiveDeref(manager,q);
Cudd_RecursiveDeref(manager,v);
cuddDeref(result);
return(result);
} else if (!Cudd_IsConstant(Nv) && Cudd_IsConstant(Nnv)) {
q = selectMintermsFromUniverse(manager,varSeen,n);
if (q == NULL) {
Cudd_RecursiveDeref(manager,v);
return(NULL);
}
cuddRef(q);
result = cuddBddAndRecur(manager,Cudd_Not(v),q);
if (result == NULL) {
Cudd_RecursiveDeref(manager,q);
Cudd_RecursiveDeref(manager,v);
return(NULL);
}
cuddRef(result);
Cudd_RecursiveDeref(manager,q);
Cudd_RecursiveDeref(manager,v);
cuddDeref(result);
return(result);
}
/* Both Nv and Nnv are not constants. So choose the one which
** has fewer minterms in its onset.
*/
positive = 0;
if (numT < numE) {
q = cuddSplitSetRecur(manager,mtable,varSeen,
Nv,n,max,index+1);
positive = 1;
} else {
q = cuddSplitSetRecur(manager,mtable,varSeen,
Nnv,n,max,index+1);
}
if (q == NULL) {
Cudd_RecursiveDeref(manager,v);
return(NULL);
}
cuddRef(q);
if (positive) {
result = cuddBddAndRecur(manager,v,q);
} else {
result = cuddBddAndRecur(manager,Cudd_Not(v),q);
}
if (result == NULL) {
Cudd_RecursiveDeref(manager,q);
Cudd_RecursiveDeref(manager,v);
return(NULL);
}
cuddRef(result);
Cudd_RecursiveDeref(manager,q);
Cudd_RecursiveDeref(manager,v);
cuddDeref(result);
return(result);
} /* end of cuddSplitSetRecur */
/**Function********************************************************************
Synopsis [Decreases the reference count of BDD node n.]
Description [Enqueues node n for later dereferencing. If the queue
is full decreases the reference count of the oldest node N to make
room for n. If N dies, recursively decreases the reference counts of
its children. It is used to dispose of a BDD that is currently not
needed, but may be useful again in the near future. The dereferencing
proper is done as in Cudd_IterDerefBdd.]
SideEffects [None]
SeeAlso [Cudd_RecursiveDeref Cudd_IterDerefBdd]
******************************************************************************/
void
Cudd_DelayedDerefBdd(
DdManager * table,
DdNode * n)
{
DdNode *N;
int ord;
DdNodePtr *stack;
int SP;
unsigned int live = table->keys - table->dead;
if (live > table->peakLiveNodes) {
table->peakLiveNodes = live;
}
n = Cudd_Regular(n);
#ifdef DD_DEBUG
assert(n->ref != 0);
#endif
#ifdef DD_NO_DEATH_ROW
N = n;
#else
if (cuddIsConstant(n) || n->ref > 1) {
#ifdef DD_DEBUG
assert(n->ref != 1 && (!cuddIsConstant(n) || n == DD_ONE(table)));
#endif
cuddSatDec(n->ref);
return;
}
N = table->deathRow[table->nextDead];
if (N != NULL) {
#endif
#ifdef DD_DEBUG
assert(!Cudd_IsComplement(N));
#endif
stack = table->stack;
SP = 1;
do {
#ifdef DD_DEBUG
assert(N->ref != 0);
#endif
if (N->ref == 1) {
N->ref = 0;
table->dead++;
#ifdef DD_STATS
table->nodesDropped++;
#endif
ord = table->perm[N->index];
stack[SP++] = Cudd_Regular(cuddE(N));
table->subtables[ord].dead++;
N = cuddT(N);
} else {
cuddSatDec(N->ref);
N = stack[--SP];
}
} while (SP != 0);
#ifndef DD_NO_DEATH_ROW
}
table->deathRow[table->nextDead] = n;
/* Udate insertion point. */
table->nextDead++;
table->nextDead &= table->deadMask;
#if 0
if (table->nextDead == table->deathRowDepth) {
if (table->deathRowDepth < table->looseUpTo / 2) {
extern void (*MMoutOfMemory)(long);
void (*saveHandler)(long) = MMoutOfMemory;
DdNodePtr *newRow;
MMoutOfMemory = Cudd_OutOfMem;
newRow = REALLOC(DdNodePtr,table->deathRow,2*table->deathRowDepth);
MMoutOfMemory = saveHandler;
if (newRow == NULL) {
table->nextDead = 0;
} else {
int i;
table->memused += table->deathRowDepth;
i = table->deathRowDepth;
table->deathRowDepth <<= 1;
for (; i < table->deathRowDepth; i++) {
newRow[i] = NULL;
}
table->deadMask = table->deathRowDepth - 1;
table->deathRow = newRow;
}
} else {
table->nextDead = 0;
}
}
#endif
#endif
} /* end of Cudd_DelayedDerefBdd */