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/* */
/**
* Calculates \exists variables . a
*/
TASK_IMPL_3(BDD, sylvan_existsRepresentative, BDD, a, BDD, variables, BDDVAR, prev_level)
{
int aIsNegated = (a & sylvan_complement) == ((uint64_t)0) ? 0 : 1;
BDD aRegular = (aIsNegated) ? sylvan_not(a) : a;
if (aRegular == sylvan_false) {
if (aIsNegated) {
if (sylvan_set_isempty(variables)) {
return sylvan_true;
} else {
//printf("return in preprocessing...3\n");
BDD _v = sylvan_set_next(variables);
BDD res = CALL(sylvan_existsRepresentative, a, _v, prev_level);
if (res == sylvan_invalid) {
return sylvan_invalid;
}
sylvan_ref(res);
BDD res1 = sylvan_ite(sylvan_ithvar(bddnode_getvariable(MTBDD_GETNODE(variables))), sylvan_false, res);
if (res1 == sylvan_invalid) {
sylvan_deref(res);
return sylvan_invalid;
}
sylvan_deref(res);
return res1;
}
} else {
return a;
}
} else if (sylvan_set_isempty(variables)) {
return a;
}
BDD result;
if (cache_get3(CACHE_MTBDD_ABSTRACT_REPRESENTATIVE, a, variables, (size_t)2, &result)) {
sylvan_stats_count(MTBDD_ABSTRACT_CACHED);
return result;
}
/* From now on, f and cube are non-constant. */
bddnode_t na = MTBDD_GETNODE(a);
BDDVAR level = bddnode_getvariable(na);
bddnode_t nv = MTBDD_GETNODE(variables);
BDDVAR vv = bddnode_getvariable(nv);
/* Abstract a variable that does not appear in f. */
if (level > vv) {
BDD _v = sylvan_set_next(variables);
BDD res = CALL(sylvan_existsRepresentative, a, _v, level);
if (res == sylvan_invalid) {
return sylvan_invalid;
}
sylvan_ref(res);
BDD res1 = sylvan_ite(sylvan_ithvar(vv), sylvan_false, res);
if (res1 == sylvan_invalid) {
sylvan_deref(res);
return sylvan_invalid;
}
sylvan_deref(res);
return res1;
}
/* Compute the cofactors of a. */
BDD aLow = node_low(a, na); // ELSE
BDD aHigh = node_high(a, na); // THEN
/* If the two indices are the same, so are their levels. */
if (level == vv) {
BDD _v = sylvan_set_next(variables);
BDD res1 = CALL(sylvan_existsRepresentative, aLow, _v, level);
if (res1 == sylvan_invalid) {
return sylvan_invalid;
}
if (res1 == sylvan_true) {
return sylvan_not(variables);
}
sylvan_ref(res1);
BDD res2 = CALL(sylvan_existsRepresentative, aHigh, _v, level);
if (res2 == sylvan_invalid) {
sylvan_deref(res1);
return sylvan_invalid;
}
sylvan_ref(res2);
BDD left = CALL(sylvan_exists, aLow, _v, 0);
if (left == sylvan_invalid) {
sylvan_deref(res1);
sylvan_deref(res2);
return sylvan_invalid;
}
sylvan_ref(left);
BDD res1Inf = sylvan_ite(left, res1, sylvan_false);
if (res1Inf == sylvan_invalid) {
sylvan_deref(res1);
sylvan_deref(res2);
sylvan_deref(left);
return sylvan_invalid;
}
sylvan_ref(res1Inf);
sylvan_deref(res1);
BDD res2Inf = sylvan_ite(left, sylvan_false, res2);
if (res2Inf == sylvan_invalid) {
sylvan_deref(res2);
sylvan_deref(left);
sylvan_deref(res1Inf);
return sylvan_invalid;
}
sylvan_ref(res2Inf);
sylvan_deref(res2);
sylvan_deref(left);
assert(res1Inf != res2Inf);
BDD res = sylvan_ite(sylvan_ithvar(level), res2Inf, res1Inf);
if (res == sylvan_invalid) {
sylvan_deref(res1Inf);
sylvan_deref(res2Inf);
return sylvan_invalid;
}
/* Store in cache */
if (cache_put3(CACHE_MTBDD_ABSTRACT_REPRESENTATIVE, a, variables, (size_t)2, res)) {
sylvan_stats_count(MTBDD_ABSTRACT_CACHEDPUT);
}
sylvan_deref(res1Inf);
sylvan_deref(res2Inf);
return res;
} else { /* if (level == vv) */
BDD res1 = CALL(sylvan_existsRepresentative, aLow, variables, level);
if (res1 == sylvan_invalid){
return sylvan_invalid;
}
sylvan_ref(res1);
BDD res2 = CALL(sylvan_existsRepresentative, aHigh, variables, level);
if (res2 == sylvan_invalid) {
sylvan_deref(res1);
return sylvan_invalid;
}
sylvan_ref(res2);
/* ITE takes care of possible complementation of res1 and of the
** case in which res1 == res2. */
BDD res = sylvan_ite(sylvan_ithvar(level), res2, res1);
if (res == sylvan_invalid) {
sylvan_deref(res1);
sylvan_deref(res2);
return sylvan_invalid;
}
sylvan_deref(res1);
sylvan_deref(res2);
/* Store in cache */
if (cache_put3(CACHE_MTBDD_ABSTRACT_REPRESENTATIVE, a, variables, (size_t)2, res)) {
sylvan_stats_count(MTBDD_ABSTRACT_CACHEDPUT);
}
return res;
}
// Prevent unused variable warning
(void)prev_level;
}