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update empty cube case for sat/undef cases

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2018-10-01 20:22:02 -07:00
parent be8a9c611e
commit 9d0aa4d02d
4 changed files with 30 additions and 18 deletions
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20
src/sat/sat_lookahead.cpp
View file

@ -2057,6 +2057,15 @@ namespace sat {
return h;
}
bool lookahead::should_cutoff(unsigned depth) {
return depth > 0 &&
((m_config.m_cube_cutoff == depth_cutoff && depth == m_config.m_cube_depth) ||
(m_config.m_cube_cutoff == freevars_cutoff && m_freevars.size() <= m_init_freevars * m_config.m_cube_freevars) ||
(m_config.m_cube_cutoff == psat_cutoff && psat_heur() >= m_config.m_cube_psat_trigger) ||
(m_config.m_cube_cutoff == adaptive_freevars_cutoff && m_freevars.size() < m_cube_state.m_freevars_threshold) ||
(m_config.m_cube_cutoff == adaptive_psat_cutoff && psat_heur() >= m_cube_state.m_psat_threshold));
}
lbool lookahead::cube(bool_var_vector& vars, literal_vector& lits, unsigned backtrack_level) {
scoped_ext _scoped_ext(*this);
lits.reset();
@ -2102,22 +2111,13 @@ namespace sat {
}
backtrack_level = UINT_MAX;
depth = m_cube_state.m_cube.size();
if ((m_config.m_cube_cutoff == depth_cutoff && depth == m_config.m_cube_depth) ||
(m_config.m_cube_cutoff == freevars_cutoff && m_freevars.size() <= m_init_freevars * m_config.m_cube_freevars) ||
(m_config.m_cube_cutoff == psat_cutoff && psat_heur() >= m_config.m_cube_psat_trigger) ||
(m_config.m_cube_cutoff == adaptive_freevars_cutoff && m_freevars.size() < m_cube_state.m_freevars_threshold) ||
(m_config.m_cube_cutoff == adaptive_psat_cutoff && psat_heur() >= m_cube_state.m_psat_threshold)) {
if (should_cutoff(depth)) {
double dec = (1.0 - pow(m_config.m_cube_fraction, depth));
m_cube_state.m_freevars_threshold *= dec;
m_cube_state.m_psat_threshold *= 2.0 - dec;
set_conflict();
m_cube_state.inc_cutoff();
#if 0
// return cube of all literals, not just the ones in the main cube
lits.append(m_trail.size() - init_trail, m_trail.c_ptr() + init_trail);
#else
lits.append(m_cube_state.m_cube);
#endif
vars.reset();
for (auto v : m_freevars) if (in_reduced_clause(v)) vars.push_back(v);
backtrack(m_cube_state.m_cube, m_cube_state.m_is_decision);

2
src/sat/sat_lookahead.h
View file

@ -558,6 +558,8 @@ namespace sat {
double psat_heur();
bool should_cutoff(unsigned depth);
public:
lookahead(solver& s) :
m_s(s),

1
src/sat/sat_solver.cpp
View file

@ -1030,6 +1030,7 @@ namespace sat {
}
break;
case l_true: {
lits.reset();
pop_to_base_level();
model const& mdl = m_cuber->get_model();
for (bool_var v = 0; v < mdl.size(); ++v) {

25
src/sat/sat_solver/inc_sat_solver.cpp
View file

@ -308,6 +308,12 @@ public:
return nullptr;
}
expr_ref_vector last_cube() {
expr_ref_vector result(m);
result.push_back(m.mk_false());
return result;
}
expr_ref_vector cube(expr_ref_vector& vs, unsigned backtrack_level) override {
if (!is_internalized()) {
lbool r = internalize_formulas();
@ -326,15 +332,18 @@ public:
}
sat::literal_vector lits;
lbool result = m_solver.cube(vars, lits, backtrack_level);
if (result == l_false || lits.empty()) {
expr_ref_vector result(m);
result.push_back(m.mk_false());
return result;
}
if (result == l_true) {
IF_VERBOSE(1, verbose_stream() << "formulas are SAT\n");
switch (result) {
case l_true:
return expr_ref_vector(m);
}
case l_false:
return last_cube();
default:
SASSERT(!lits.empty());
if (lits.empty()) {
IF_VERBOSE(0, verbose_stream() << "empty cube for undef\n";);
}
break;
}
expr_ref_vector fmls(m);
expr_ref_vector lit2expr(m);
lit2expr.resize(m_solver.num_vars() * 2);