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flip literals in ATEs produced using RI

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2018-04-06 08:38:01 -07:00
parent 528dc8a3f8
commit a954ab7d8d
7 changed files with 224 additions and 85 deletions

View file

@ -939,16 +939,21 @@ namespace sat {
bool operator==(clause_ante const& a) const {
return a.m_lit1 == m_lit1 && a.m_lit2 == m_lit2 && a.m_clause == m_clause;
}
std::ostream& display(std::ostream& out) const {
std::ostream& display(std::ostream& out, literal lit) const {
if (cls()) {
out << *cls() << " ";
}
else {
out << "(" << ~lit;
}
if (lit1() != null_literal) {
out << lit1() << " ";
out << " " << lit1();
}
if (lit2() != null_literal) {
out << lit2() << " ";
out << " " << lit2();
}
if (!cls()) out << ")";
if (from_ri()) out << "ri";
out << "\n";
return out;
}
@ -978,7 +983,7 @@ namespace sat {
simplifier & s;
int m_counter;
model_converter & mc;
model_converter & m_mc;
queue m_queue;
literal_vector m_covered_clause; // covered clause
@ -987,7 +992,6 @@ namespace sat {
literal_vector m_tautology; // literals that are used in blocking tautology
literal_vector m_new_intersection;
svector<bool> m_in_intersection;
sat::model_converter::elim_stackv m_elim_stack;
unsigned m_ala_qhead;
clause_wrapper m_clause;
@ -995,7 +999,7 @@ namespace sat {
vector<watch_list> & wlist):
s(_s),
m_counter(limit),
mc(_mc),
m_mc(_mc),
m_queue(l, wlist),
m_clause(null_literal, null_literal) {
m_in_intersection.resize(s.s.num_vars() * 2, false);
@ -1069,6 +1073,7 @@ namespace sat {
m_tautology.reset();
if (!process_var(l.var())) return false;
bool first = true;
VERIFY(s.value(l) == l_undef);
for (watched & w : s.get_wlist(l)) {
// when adding a blocked clause, then all non-learned clauses have to be considered for the
// resolution intersection.
@ -1184,18 +1189,18 @@ namespace sat {
if (m_covered_antecedent[i] == clause_ante()) s.mark_visited(lit);
if (s.is_marked(lit)) idx = i;
}
if (false && _blocked.var() == 16774) {
if (false) {
IF_VERBOSE(0, verbose_stream() << "covered: " << m_covered_clause << "\n";
verbose_stream() << "tautology: " << m_tautology << "\n";
verbose_stream() << "index: " << idx << "\n";
for (unsigned i = idx; i > 0; --i) {
m_covered_antecedent[i].display(verbose_stream() << "ante " << m_covered_clause[i] << ":");
m_covered_antecedent[i].display(verbose_stream(), m_covered_clause[i]);
});
}
for (unsigned i = idx; i > 0; --i) {
literal lit = m_covered_clause[i];
s.mark_visited(lit);
continue;
//s.mark_visited(lit);
//continue;
if (!s.is_marked(lit)) continue;
clause_ante const& ante = m_covered_antecedent[i];
if (ante.cls()) {
@ -1222,13 +1227,16 @@ namespace sat {
clause_ante const& ante = m_covered_antecedent[i];
if (ante.from_ri() && blocked != ante.lit1()) {
blocked = ante.lit1();
m_elim_stack.push_back(std::make_pair(j, blocked));
VERIFY(s.value(blocked) == l_undef);
m_mc.stackv().push_back(std::make_pair(j, blocked));
}
m_covered_clause[j++] = lit;
s.unmark_visited(lit);
}
}
for (literal l : m_covered_clause) VERIFY(!s.is_marked(l));
for (bool_var v = 0; v < s.s.num_vars(); ++v) VERIFY(!s.is_marked(literal(v, true)) && !s.is_marked(literal(v, false)));
// unsigned sz0 = m_covered_clause.size();
m_covered_clause.resize(j);
VERIFY(j >= m_clause.size());
@ -1263,6 +1271,7 @@ namespace sat {
return true;
}
if (!s.is_marked(~lit)) {
// if (m_covered_clause[0].var() == 10219) IF_VERBOSE(0, verbose_stream() << "ala: " << l << " " << lit << "\n");
m_covered_clause.push_back(~lit);
m_covered_antecedent.push_back(clause_ante(l, false));
s.mark_visited(~lit);
@ -1292,6 +1301,7 @@ namespace sat {
if (lit1 == null_literal) {
return true;
}
// if (m_covered_clause[0].var() == 10219) IF_VERBOSE(0, verbose_stream() << "ala: " << c << " " << lit1 << "\n");
m_covered_clause.push_back(~lit1);
m_covered_antecedent.push_back(clause_ante(c));
s.mark_visited(~lit1);
@ -1332,13 +1342,17 @@ namespace sat {
return sz0 * 400 < m_covered_clause.size();
}
void reset_mark() {
for (literal l : m_covered_clause) s.unmark_visited(l);
}
template<elim_type et>
elim_type cce(literal& blocked, model_converter::kind& k) {
bool is_tautology = false, first = true;
bool first = true;
unsigned sz = 0, sz0 = m_covered_clause.size();
for (literal l : m_covered_clause) s.mark_visited(l);
shuffle<literal>(m_covered_clause.size(), m_covered_clause.c_ptr(), s.s.m_rand);
m_elim_stack.reset();
m_mc.stackv().reset();
m_ala_qhead = 0;
switch (et) {
@ -1349,7 +1363,7 @@ namespace sat {
k = model_converter::ACCE;
break;
default:
k = model_converter::BLOCK_LIT;
k = model_converter::BCE;
break;
}
@ -1361,48 +1375,77 @@ namespace sat {
* and then check if any of the first sz0 literals are blocked.
*/
while (!is_tautology && m_covered_clause.size() > sz && !above_threshold(sz0)) {
SASSERT(!is_tautology);
if (et == ate_t) {
bool ala = add_ala();
reset_mark();
m_covered_clause.shrink(sz0);
return ala ? ate_t : no_t;
}
if ((et == abce_t || et == acce_t || et == ate_t) && add_ala()) {
for (literal l : m_covered_clause) s.unmark_visited(l);
while (m_covered_clause.size() > sz && !above_threshold(sz0)) {
if ((et == abce_t || et == acce_t) && add_ala()) {
reset_mark();
if (first) {
m_covered_clause.shrink(sz0);
}
else {
/*
* tautology depends on resolution intersection.
* literals used for resolution intersection may have to be flipped.
*/
m_tautology.reset();
for (literal l : m_covered_clause) {
m_tautology.push_back(l);
s.mark_visited(l);
}
minimize_covered_clause(m_covered_clause.size()-1);
}
return ate_t;
}
if (et == ate_t) {
for (literal l : m_covered_clause) s.unmark_visited(l);
return no_t;
}
if (first) {
for (unsigned i = 0; i < sz0; ++i) {
if (check_abce_tautology(m_covered_clause[i])) {
blocked = m_covered_clause[i];
is_tautology = true;
break;
reset_mark();
#if 0
if (sz0 == 3 && blocked.var() == 10219) {
IF_VERBOSE(0, verbose_stream() << "abce: " << m_covered_clause << "\n";
for (literal l : m_covered_clause) verbose_stream() << s.value(l) << "\n";
);
literal l = blocked;
clause_use_list & neg_occs = s.m_use_list.get(~l);
for (auto it = neg_occs.mk_iterator(); !it.at_end(); it.next()) {
clause & c = it.curr();
IF_VERBOSE(0, verbose_stream() << c << "\n");
}
}
#endif
m_covered_clause.shrink(sz0);
if (et == bce_t) return bce_t;
k = model_converter::ABCE;
return abce_t;
}
}
first = false;
}
first = false;
if (is_tautology || et == abce_t || et == bce_t) {
for (literal l : m_covered_clause) s.unmark_visited(l);
m_covered_clause.shrink(sz0);
if (!is_tautology) return no_t;
if (et == bce_t) return bce_t;
return abce_t;
if (et == abce_t || et == bce_t) {
break;
}
/*
* Add resolution intersection while checking if the clause becomes a tautology.
*/
sz = m_covered_clause.size();
if (et == cce_t || et == acce_t) {
is_tautology = add_cla(blocked);
if ((et == cce_t || et == acce_t) && add_cla(blocked)) {
reset_mark();
return et;
}
}
for (literal l : m_covered_clause) s.unmark_visited(l);
return is_tautology ? et : no_t;
reset_mark();
return no_t;
}
// perform covered clause elimination.
@ -1463,13 +1506,14 @@ namespace sat {
case ate_t:
w.set_learned(true);
s.s.set_learned1(l2, l, true);
m_mc.add_ate(m_covered_clause);
break;
case no_t:
break;
default:
block_covered_binary(w, l, blocked, k);
w.set_learned(true);
s.s.set_learned1(l2, l, true);
block_covered_binary(w, l, blocked, k);
break;
}
}
@ -1487,7 +1531,8 @@ namespace sat {
inc_bc(r);
switch (r) {
case ate_t:
s.set_learned(c);
m_mc.add_ate(m_covered_clause);
s.set_learned(c);
break;
case no_t:
break;
@ -1518,32 +1563,33 @@ namespace sat {
}
void block_covered_clause(clause& c, literal l, model_converter::kind k) {
if (false && l.var() == 39021) {
if (false) {
IF_VERBOSE(0, verbose_stream() << "blocked: " << l << " @ " << c << " :covered " << m_covered_clause << "\n";
s.m_use_list.display(verbose_stream() << "use " << l << ":", l);
s.m_use_list.display(verbose_stream() << "use " << ~l << ":", ~l);
/*s.s.display(verbose_stream());*/
display_watch_list(verbose_stream() << ~l << ": ", s.s.m_cls_allocator, s.get_wlist(l)) << "\n";
display_watch_list(verbose_stream() << l << ": ", s.s.m_cls_allocator, s.get_wlist(~l)) << "\n";
);
}
TRACE("blocked_clause", tout << "new blocked clause: " << c << "\n";);
SASSERT(!s.is_external(l));
model_converter::entry& new_entry = mc.mk(k, l.var());
model_converter::entry& new_entry = m_mc.mk(k, l.var());
for (literal lit : c) {
if (lit != l && process_var(lit.var())) {
m_queue.decreased(~lit);
}
}
mc.insert(new_entry, m_covered_clause, m_elim_stack);
m_mc.insert(new_entry, m_covered_clause);
}
void block_covered_binary(watched const& w, literal l1, literal blocked, model_converter::kind k) {
SASSERT(!s.is_external(blocked));
model_converter::entry& new_entry = mc.mk(k, blocked.var());
model_converter::entry& new_entry = m_mc.mk(k, blocked.var());
literal l2 = w.get_literal();
TRACE("blocked_clause", tout << "new blocked clause: " << l2 << " " << l1 << "\n";);
s.set_learned(l1, l2);
mc.insert(new_entry, m_covered_clause, m_elim_stack);
m_mc.insert(new_entry, m_covered_clause);
m_queue.decreased(~l2);
}
@ -1571,6 +1617,13 @@ namespace sat {
for (literal l2 : m_intersection) {
watched* w = find_binary_watch(s.get_wlist(~l), ~l2);
if (!w) {
#if 0
IF_VERBOSE(0, verbose_stream() << "bca " << l << " " << ~l2 << "\n");
if (l.var() == 10219 && l2.var() == 10202) {
IF_VERBOSE(0, s.s.display(verbose_stream()));
exit(0);
}
#endif
s.s.mk_bin_clause(l, ~l2, true);
++s.m_num_bca;
}
@ -1777,13 +1830,19 @@ namespace sat {
}
void simplifier::save_clauses(model_converter::entry & mc_entry, clause_wrapper_vector const & cs) {
model_converter & mc = s.m_mc;
for (auto & e : cs) {
mc.insert(mc_entry, e);
s.m_mc.insert(mc_entry, e);
}
}
void simplifier::add_non_learned_binary_clause(literal l1, literal l2) {
#if 0
if ((l1.var() == 2039 || l2.var() == 2039) &&
(l1.var() == 27042 || l2.var() == 27042)) {
IF_VERBOSE(1, verbose_stream() << "add_bin: " << l1 << " " << l2 << "\n");
}
#endif
#if 0
watched* w;
watch_list & wlist1 = get_wlist(~l1);
watch_list & wlist2 = get_wlist(~l2);
@ -1804,6 +1863,9 @@ namespace sat {
else {
wlist2.push_back(watched(l1, false));
}
#else
s.mk_bin_clause(l1, l2, false);
#endif
}
/**
@ -1820,6 +1882,11 @@ namespace sat {
watch_list::iterator end2 = wlist2.end();
for (; it2 != end2; ++it2) {
if (it2->is_binary_clause() && it2->get_literal() == l) {
if ((l.var() == 2039 || l2.var() == 2039) &&
(l.var() == 27042 || l2.var() == 27042)) {
IF_VERBOSE(1, verbose_stream() << "remove_bin: " << l << " " << l2 << "\n");
}
TRACE("bin_clause_bug", tout << "removing: " << l << " " << it2->get_literal() << "\n";);
m_sub_bin_todo.erase(bin_clause(l2, l, it2->is_learned()));
continue;
@ -1920,6 +1987,13 @@ namespace sat {
m_elim_counter -= num_pos * num_neg + before_lits;
if (false) {
literal l(v, false);
IF_VERBOSE(0,
verbose_stream() << "elim: " << l << "\n";
display_watch_list(verbose_stream() << ~l << ": ", s.m_cls_allocator, get_wlist(l)) << "\n";
display_watch_list(verbose_stream() << l << ": ", s.m_cls_allocator, get_wlist(~l)) << "\n";);
}
// eliminate variable
++s.m_stats.m_elim_var_res;
VERIFY(!is_external(v));
@ -1936,12 +2010,14 @@ namespace sat {
m_elim_counter -= num_pos * num_neg + before_lits;
for (auto & c1 : m_pos_cls) {
for (auto & c2 : m_neg_cls) {
m_new_cls.reset();
if (!resolve(c1, c2, pos_l, m_new_cls))
continue;
// if (v == 39063) IF_VERBOSE(0, verbose_stream() << "elim: " << c1 << " + " << c2 << " -> " << m_new_cls << "\n");
if (false && v == 27041) IF_VERBOSE(0, verbose_stream() << "elim: " << c1 << " + " << c2 << " -> " << m_new_cls << "\n");
TRACE("resolution_new_cls", tout << c1 << "\n" << c2 << "\n-->\n" << m_new_cls << "\n";);
if (cleanup_clause(m_new_cls))
continue; // clause is already satisfied.
@ -2053,7 +2129,7 @@ namespace sat {
m_subsumption = p.subsumption();
m_subsumption_limit = p.subsumption_limit();
m_elim_vars = p.elim_vars();
m_elim_vars_bdd = false && p.elim_vars_bdd(); // buggy
m_elim_vars_bdd = false && p.elim_vars_bdd(); // buggy?
m_elim_vars_bdd_delay = p.elim_vars_bdd_delay();
m_incremental_mode = s.get_config().m_incremental && !p.override_incremental();
}