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fix non-termination bug with retained clauses

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2017-10-25 15:40:11 -07:00
parent 32711790e8
commit ac0202630e
6 changed files with 36 additions and 77 deletions
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3
src/ast/ast.cpp
View file

@ -2254,9 +2254,10 @@ func_decl * ast_manager::mk_fresh_func_decl(symbol const & prefix, symbol const
}
else {
string_buffer<64> buffer;
buffer << prefix;
if (prefix == symbol::null)
buffer << "sk";
else
buffer << prefix;
buffer << "!";
if (suffix != symbol::null)
buffer << suffix << "!";

2
src/ast/bv_decl_plugin.cpp
View file

@ -717,7 +717,7 @@ void bv_decl_plugin::get_op_names(svector<builtin_name> & op_names, symbol const
op_names.push_back(builtin_name("rotate_left",OP_ROTATE_LEFT));
op_names.push_back(builtin_name("rotate_right",OP_ROTATE_RIGHT));
if (logic == symbol::null) {
if (logic == symbol::null || logic == "QF_FD") {
op_names.push_back(builtin_name("bvumul_noovfl",OP_BUMUL_NO_OVFL));
op_names.push_back(builtin_name("bvsmul_noovfl",OP_BSMUL_NO_OVFL));
op_names.push_back(builtin_name("bvsmul_noudfl",OP_BSMUL_NO_UDFL));

17
src/sat/sat_elim_vars.cpp
View file

@ -302,17 +302,16 @@ namespace sat{
}
bdd elim_vars::make_clauses(clause_use_list & occs) {
bdd result = m.mk_true();
clause_use_list::iterator it = occs.mk_iterator();
while (!it.at_end()) {
bdd result = m.mk_true();
for (auto it = occs.mk_iterator(); !it.at_end(); it.next()) {
clause const& c = it.curr();
if (c.is_blocked()) continue;
bdd cl = m.mk_false();
for (literal l : c) {
cl |= mk_literal(l);
if (!c.is_blocked()) {
bdd cl = m.mk_false();
for (literal l : c) {
cl |= mk_literal(l);
}
result &= cl;
}
it.next();
result &= cl;
}
return result;
}

88
src/sat/sat_simplifier.cpp
View file

@ -418,8 +418,7 @@ namespace sat {
literal target) {
if (c1.is_blocked()) return;
clause_use_list const & cs = m_use_list.get(target);
clause_use_list::iterator it = cs.mk_iterator();
while (!it.at_end()) {
for (auto it = cs.mk_iterator(); !it.at_end(); it.next()) {
clause & c2 = it.curr();
CTRACE("resolution_bug", c2.was_removed(), tout << "clause has been removed:\n" << c2 << "\n";);
SASSERT(!c2.was_removed());
@ -433,7 +432,6 @@ namespace sat {
out_lits.push_back(l);
}
}
it.next();
}
}
@ -532,7 +530,7 @@ namespace sat {
if (c1.is_blocked()) return;
clause_use_list const & cs = m_use_list.get(target);
clause_use_list::iterator it = cs.mk_iterator();
while (!it.at_end()) {
for (; !it.at_end(); it.next()) {
clause & c2 = it.curr();
SASSERT(!c2.was_removed());
if (&c2 != &c1 &&
@ -543,7 +541,6 @@ namespace sat {
out.push_back(&c2);
}
}
it.next();
}
}
@ -652,29 +649,16 @@ namespace sat {
unsigned new_trail_sz = s.m_trail.size();
for (unsigned i = old_trail_sz; i < new_trail_sz; i++) {
literal l = s.m_trail[i];
{
// put clauses with literals assigned to false back into todo-list
clause_use_list & cs = m_use_list.get(~l);
clause_use_list::iterator it = cs.mk_iterator();
while (!it.at_end()) {
clause & c = it.curr();
it.next();
m_sub_todo.insert(c);
}
// put clauses with literals assigned to false back into todo-list
for (auto it = m_use_list.get(~l).mk_iterator(); !it.at_end(); it.next()) {
m_sub_todo.insert(it.curr());
}
{
// erase satisfied clauses
clause_use_list & cs = m_use_list.get(l);
{
clause_use_list::iterator it = cs.mk_iterator();
while (!it.at_end()) {
clause & c = it.curr();
it.next();
remove_clause(c, l);
}
}
cs.reset();
clause_use_list& cs = m_use_list.get(l);
for (auto it = cs.mk_iterator(); !it.at_end(); it.next()) {
clause & c = it.curr();
remove_clause(c, l);
}
cs.reset();
}
}
@ -1338,12 +1322,8 @@ namespace sat {
}
if (!found) {
IF_VERBOSE(100, verbose_stream() << "bca " << l << " " << l2 << "\n";);
watched w(l2, false);
w.set_blocked();
s.get_wlist(~l).push_back(w);
w = watched(l, false);
w.set_blocked();
s.get_wlist(~l2).push_back(w);
s.get_wlist(~l).push_back(watched(l2, true));
s.get_wlist(~l2).push_back(watched(l, true));
++s.m_num_bca;
}
}
@ -1473,29 +1453,18 @@ namespace sat {
void simplifier::collect_clauses(literal l, clause_wrapper_vector & r, bool include_blocked) {
clause_use_list const & cs = m_use_list.get(l);
clause_use_list::iterator it = cs.mk_iterator();
while (!it.at_end()) {
for (; !it.at_end(); it.next()) {
if (!it.curr().is_blocked() || include_blocked) {
r.push_back(clause_wrapper(it.curr()));
SASSERT(r.back().size() == it.curr().size());
}
it.next();
}
watch_list & wlist = get_wlist(~l);
if (include_blocked) {
for (auto & w : wlist) {
if (w.is_binary_non_learned_clause2()) {
r.push_back(clause_wrapper(l, w.get_literal()));
SASSERT(r.back().size() == 2);
}
}
}
else {
for (auto & w : wlist) {
if (w.is_binary_unblocked_clause()) {
r.push_back(clause_wrapper(l, w.get_literal()));
SASSERT(r.back().size() == 2);
}
for (auto & w : wlist) {
if (include_blocked ? w.is_binary_non_learned_clause() : w.is_binary_unblocked_clause()) {
r.push_back(clause_wrapper(l, w.get_literal()));
SASSERT(r.back().size() == 2);
}
}
}
@ -1607,8 +1576,7 @@ namespace sat {
\brief Eliminate the clauses where the variable being eliminated occur.
*/
void simplifier::remove_clauses(clause_use_list const & cs, literal l) {
clause_use_list::iterator it = cs.mk_iterator();
while (!it.at_end()) {
for (auto it = cs.mk_iterator(); !it.at_end(); ) {
clause & c = it.curr();
it.next();
SASSERT(c.contains(l));
@ -1641,22 +1609,14 @@ namespace sat {
unsigned before_lits = num_bin_pos*2 + num_bin_neg*2;
{
clause_use_list::iterator it = pos_occs.mk_iterator();
while (!it.at_end()) {
if (!it.curr().is_blocked())
before_lits += it.curr().size();
it.next();
}
for (auto it = pos_occs.mk_iterator(); !it.at_end(); it.next()) {
if (!it.curr().is_blocked())
before_lits += it.curr().size();
}
{
clause_use_list::iterator it2 = neg_occs.mk_iterator();
while (!it2.at_end()) {
if (!it2.curr().is_blocked())
before_lits += it2.curr().size();
it2.next();
}
for (auto it = neg_occs.mk_iterator(); !it.at_end(); it.next()) {
if (!it.curr().is_blocked())
before_lits += it.curr().size();
}
TRACE("resolution", tout << v << " num_pos: " << num_pos << " neg_pos: " << num_neg << " before_lits: " << before_lits << "\n";);

2
src/sat/sat_watched.h
View file

@ -88,7 +88,7 @@ namespace sat {
bool is_binary_unblocked_clause() const { return m_val2 == 0; }
bool is_binary_learned_clause() const { return is_binary_clause() && is_learned(); }
bool is_binary_non_learned_clause2() const { return is_binary_clause() && !is_learned(); }
bool is_binary_non_learned_clause() const { return is_binary_clause() && !is_learned(); }
void mark_not_learned() { SASSERT(is_learned()); m_val2 = static_cast<unsigned>(BINARY); SASSERT(!is_learned()); }
void set_blocked() { SASSERT(is_binary_clause()); SASSERT(!is_learned()); m_val2 |= (1 << 3); }

1
src/sat/tactic/goal2sat.cpp
View file

@ -1110,7 +1110,6 @@ struct sat2goal::imp {
r.assert_expr(m.mk_false());
return;
}
IF_VERBOSE(1, verbose_stream() << "solver2goal " << s.num_vars() << " " << s.clauses().size() << "\n";);
init_lit2expr(s, map, mc, r.models_enabled());
// collect units
unsigned num_vars = s.num_vars();