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mirror of https://github.com/Z3Prover/z3 synced 2025-04-15 13:28:47 +00:00
This commit is contained in:
Nikolaj Bjorner 2017-10-19 22:19:12 -07:00
commit 42749e7b22
2 changed files with 30 additions and 5 deletions

View file

@ -340,6 +340,13 @@ namespace sat {
}
bool lookahead::is_unsat() const {
for (unsigned idx = 0; idx < m_binary.size(); ++idx) {
literal l = to_literal(idx);
for (literal lit : m_binary[idx]) {
if (is_true(l) && is_false(lit))
return true;
}
}
// check if there is a clause whose literals are false.
// every clause is terminated by a null-literal.
for (nary* n : m_nary_clauses) {
@ -440,8 +447,21 @@ namespace sat {
bool lookahead::missed_conflict() const {
if (inconsistent()) return false;
for (literal l1 : m_trail) {
for (literal l2 : m_binary[l1.index()]) {
if (is_false(l2))
return true;
}
unsigned sz = m_ternary_count[(~l1).index()];
for (binary b : m_ternary[(~l1).index()]) {
if (sz-- == 0) break;
if ((is_false(b.m_u) && is_false(b.m_v)))
return true;
}
}
for (nary * n : m_nary_clauses) {
if (n->size() == 0) return true;
if (n->size() == 0)
return true;
}
return false;
}
@ -1464,7 +1484,7 @@ namespace sat {
sz = m_nary_count[l.index()];
for (nary* n : m_nary[l.index()]) {
if (sz-- == 0) break;
if (m_stamp[l.var()] > m_stamp[n->get_head().var()]) {
if (get_level(l) > get_level(n->get_head())) {
n->set_head(l);
}
}
@ -1660,6 +1680,7 @@ namespace sat {
num_units += do_double(lit, dl_lvl);
if (dl_lvl > level) {
base = dl_lvl;
SASSERT(get_level(m_trail.back()) == base + m_lookahead[i].m_offset);
}
unsat = inconsistent();
pop_lookahead1(lit, num_units);
@ -1785,11 +1806,12 @@ namespace sat {
base += m_lookahead.size();
unsigned dl_truth = base + m_lookahead.size() * m_config.m_dl_max_iterations;
scoped_level _sl(*this, dl_truth);
SASSERT(get_level(m_trail.back()) == dl_truth);
SASSERT(is_fixed(l));
IF_VERBOSE(2, verbose_stream() << "double: " << l << " depth: " << m_trail_lim.size() << "\n";);
lookahead_backtrack();
assign(l);
propagate();
//SASSERT(!inconsistent());
unsigned old_sz = m_trail.size();
bool change = true;
literal last_changed = null_literal;
@ -1830,6 +1852,8 @@ namespace sat {
base += 2 * m_lookahead.size();
SASSERT(dl_truth >= base);
}
lookahead_backtrack();
SASSERT(get_level(m_trail.back()) == dl_truth);
SASSERT(m_level == dl_truth);
base = dl_truth;
return m_trail.size() - old_sz;
@ -1848,6 +1872,7 @@ namespace sat {
if (is_undef(l)) {
TRACE("sat", tout << "assign: " << l << " @ " << m_level << " " << m_trail_lim.size() << " " << m_search_mode << "\n";);
set_true(l);
SASSERT(m_trail.empty() || get_level(m_trail.back()) >= get_level(l));
m_trail.push_back(l);
if (m_search_mode == lookahead_mode::searching) {
m_stats.m_propagations++;

View file

@ -90,7 +90,7 @@ namespace sat {
m_min_cutoff = 30;
m_preselect = false;
m_level_cand = 600;
m_delta_rho = (double)0.85;
m_delta_rho = (double)0.7;
m_dl_max_iterations = 2;
m_tc1_limit = 10000000;
m_reward_type = ternary_reward;
@ -246,8 +246,8 @@ namespace sat {
inline bool is_true(literal l) const { return is_true_at(l, m_level); }
inline void set_true(literal l) { m_stamp[l.var()] = m_level + l.sign(); }
inline void set_undef(literal l) { m_stamp[l.var()] = 0; }
inline unsigned get_level(literal l) const { return m_stamp[l.var()] & UINT_MAX - 1; }
void set_level(literal d, literal s) { m_stamp[d.var()] = (m_stamp[s.var()] & ~0x1) + d.sign(); }
unsigned get_level(literal d) const { return m_stamp[d.var()]; }
lbool value(literal l) const { return is_undef(l) ? l_undef : is_true(l) ? l_true : l_false; }
// set the level within a scope of the search.