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add option for using corr set and use partial cores

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2015-08-30 14:48:24 -07:00
parent 7f219e84de
commit 0ed38ed59b
6 changed files with 84 additions and 18 deletions
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69
src/opt/maxres.cpp
View file

@ -93,6 +93,8 @@ private:
expr_ref_vector m_trail;
strategy_t m_st;
rational m_max_upper;
model_ref m_csmodel;
unsigned m_correction_set_size;
bool m_found_feasible_optimum;
bool m_hill_climb; // prefer large weight soft clauses for cores
unsigned m_last_index; // last index used during hill-climbing
@ -103,6 +105,7 @@ private:
unsigned m_max_correction_set_size;// maximal set of correction set that is tolerated.
bool m_wmax; // Block upper bound using wmax
// this option is disabled if SAT core is used.
bool m_pivot_on_cs; // prefer smaller correction set to core.
bool m_dump_benchmarks; // display benchmarks (into wcnf format)
std::string m_trace_id;
@ -118,6 +121,7 @@ public:
m_mss(c.get_solver(), m),
m_trail(m),
m_st(st),
m_correction_set_size(0),
m_found_feasible_optimum(false),
m_hill_climb(true),
m_last_index(0),
@ -125,7 +129,8 @@ public:
m_max_num_cores(UINT_MAX),
m_max_core_size(3),
m_maximize_assignment(false),
m_max_correction_set_size(3)
m_max_correction_set_size(3),
m_pivot_on_cs(true)
{
switch(st) {
case s_primal:
@ -203,7 +208,12 @@ public:
return l_true;
case l_false:
is_sat = process_unsat();
if (is_sat != l_true) return is_sat;
if (is_sat == l_false) {
m_lower = m_upper;
}
if (is_sat == l_undef) {
return is_sat;
}
break;
case l_undef:
return l_undef;
@ -386,7 +396,6 @@ public:
}
void get_current_correction_set(model* mdl, exprs& cs) {
++m_stats.m_num_cs;
cs.reset();
if (!mdl) return;
for (unsigned i = 0; i < m_asms.size(); ++i) {
@ -428,12 +437,15 @@ public:
}
void process_sat(exprs const& corr_set) {
++m_stats.m_num_cs;
expr_ref fml(m), tmp(m);
TRACE("opt", display_vec(tout << "corr_set: ", corr_set););
remove_core(corr_set);
rational w = split_core(corr_set);
cs_max_resolve(corr_set, w);
IF_VERBOSE(2, verbose_stream() << "(opt.maxres.correction-set " << corr_set.size() << ")\n";);
m_csmodel = 0;
m_correction_set_size = 0;
}
lbool process_unsat() {
@ -464,8 +476,19 @@ public:
process_unsat(cores[i]);
}
}
void update_model(expr* def, expr* value) {
SASSERT(is_uninterp_const(def));
if (m_csmodel) {
expr_ref val(m);
SASSERT(m_csmodel.get());
VERIFY(m_csmodel->eval(value, val));
m_csmodel->register_decl(to_app(def)->get_decl(), val);
}
}
void process_unsat(exprs const& core) {
IF_VERBOSE(3, verbose_stream() << "(maxres cs model valid: " << (m_csmodel.get() != 0) << " cs size:" << m_correction_set_size << " core: " << core.size() << ")\n";);
expr_ref fml(m);
remove_core(core);
SASSERT(!core.empty());
@ -479,7 +502,20 @@ public:
if (m_st == s_primal_dual) {
m_lower = std::min(m_lower, m_upper);
}
if (m_csmodel.get() && m_correction_set_size > 0) {
// this estimate can overshoot for weighted soft constraints.
--m_correction_set_size;
}
trace();
if (m_pivot_on_cs && m_csmodel.get() && m_correction_set_size < core.size()) {
exprs cs;
get_current_correction_set(m_csmodel.get(), cs);
m_correction_set_size = cs.size();
if (m_correction_set_size < core.size()) {
process_sat(cs);
return;
}
}
}
bool get_mus_model(model_ref& mdl) {
@ -601,11 +637,14 @@ public:
fml = m.mk_implies(dd, b_i);
s().assert_expr(fml);
m_defs.push_back(fml);
fml = m.mk_and(d, b_i);
update_model(dd, fml);
d = dd;
}
asum = mk_fresh_bool("a");
cls = m.mk_or(b_i1, d);
fml = m.mk_implies(asum, cls);
update_model(asum, cls);
new_assumption(asum, w);
s().assert_expr(fml);
m_defs.push_back(fml);
@ -638,8 +677,10 @@ public:
if (i > 2) {
d = mk_fresh_bool("d");
fml = m.mk_implies(d, cls);
update_model(d, cls);
s().assert_expr(fml);
m_defs.push_back(fml);
}
else {
d = cls;
@ -652,12 +693,25 @@ public:
s().assert_expr(fml);
m_defs.push_back(fml);
new_assumption(asum, w);
fml = m.mk_and(b_i1, cls);
update_model(asum, fml);
}
fml = m.mk_or(m_B.size(), m_B.c_ptr());
s().assert_expr(fml);
}
void update_assignment(model* mdl) {
unsigned correction_set_size = 0;
for (unsigned i = 0; i < m_asms.size(); ++i) {
if (is_false(mdl, m_asms[i].get())) {
++correction_set_size;
}
}
if (!m_csmodel.get() || correction_set_size < m_correction_set_size) {
m_csmodel = mdl;
m_correction_set_size = correction_set_size;
}
rational upper(0);
expr_ref tmp(m);
for (unsigned i = 0; i < m_soft.size(); ++i) {
@ -665,16 +719,18 @@ public:
upper += m_weights[i];
}
}
if (upper >= m_upper) {
return;
}
m_model = mdl;
for (unsigned i = 0; i < m_soft.size(); ++i) {
m_assignment[i] = is_true(m_soft[i]);
}
m_upper = upper;
DEBUG_CODE(verify_assignment(););
m_upper = upper;
trace();
add_upper_bound_block();
@ -744,6 +800,7 @@ public:
m_max_core_size = _p.maxres_max_core_size();
m_maximize_assignment = _p.maxres_maximize_assignment();
m_max_correction_set_size = _p.maxres_max_correction_set_size();
m_pivot_on_cs = _p.maxres_pivot_on_correction_set();
m_wmax = _p.maxres_wmax();
m_dump_benchmarks = _p.dump_benchmarks();
}
@ -759,6 +816,8 @@ public:
m_found_feasible_optimum = false;
m_last_index = 0;
add_upper_bound_block();
m_csmodel = 0;
m_correction_set_size = 0;
}
virtual void commit_assignment() {

1
src/opt/maxsmt.cpp
View file

@ -94,6 +94,7 @@ namespace opt {
void maxsmt_solver_base::set_mus(bool f) {
params_ref p;
p.set_bool("minimize_core", f);
// p.set_bool("minimize_core_partial", f);
s().updt_params(p);
}

3
src/opt/opt_params.pyg
View file

@ -18,7 +18,8 @@ def_module_params('opt',
('maxres.max_core_size', UINT, 3, 'break batch of generated cores if size reaches this number'),
('maxres.maximize_assignment', BOOL, False, 'find an MSS/MCS to improve current assignment'),
('maxres.max_correction_set_size', UINT, 3, 'allow generating correction set constraints up to maximal size'),
('maxres.wmax', BOOL, False, 'use weighted theory solver to constrain upper bounds')
('maxres.wmax', BOOL, False, 'use weighted theory solver to constrain upper bounds'),
('maxres.pivot_on_correction_set', BOOL, True, 'prefer reducing soft constraints if the current correction set is smaller than current core')
))

14
src/sat/sat_mus.cpp
View file

@ -33,7 +33,7 @@ namespace sat {
m_mus.reset();
m_model.reset();
m_best_value = 0;
m_max_restarts = 10;
m_max_restarts = (s.m_stats.m_restart - m_restart) + 10;
m_restart = s.m_stats.m_restart;
}
@ -59,12 +59,13 @@ namespace sat {
lbool mus::operator()() {
flet<bool> _disable_min(s.m_config.m_minimize_core, false);
flet<bool> _disable_min_partial(s.m_config.m_minimize_core_partial, false);
flet<bool> _disable_opt(s.m_config.m_optimize_model, false);
flet<bool> _is_active(m_is_active, true);
IF_VERBOSE(3, verbose_stream() << "(sat.mus " << s.get_core() << ")\n";);
reset();
return mus1();
lbool r = mus1();
m_restart = s.m_stats.m_restart;
return r;
}
lbool mus::mus1() {
@ -95,6 +96,11 @@ namespace sat {
// IF_VERBOSE(0, verbose_stream() << "num literals: " << core << " " << mus << "\n";);
break;
}
if (s.m_config.m_minimize_core_partial && s.m_stats.m_restart - m_restart > m_max_restarts) {
IF_VERBOSE(1, verbose_stream() << "restart budget exceeded\n";);
set_core();
return l_true;
}
literal lit = core.back();
core.pop_back();
@ -166,7 +172,7 @@ namespace sat {
lbool mus::qx(literal_set& assignment, literal_set& support, bool has_support) {
lbool is_sat = l_true;
if (s.m_stats.m_restart - m_restart > m_max_restarts) {
if (s.m_config.m_minimize_core_partial && s.m_stats.m_restart - m_restart > m_max_restarts) {
IF_VERBOSE(1, verbose_stream() << "restart budget exceeded\n";);
return l_true;
}

3
src/sat/sat_solver.cpp
View file

@ -940,7 +940,6 @@ namespace sat {
bool solver::init_weighted_assumptions(unsigned num_lits, literal const* lits, double const* weights, double max_weight) {
flet<bool> _min1(m_config.m_minimize_core, false);
flet<bool> _min2(m_config.m_minimize_core_partial, false);
m_weight = 0;
m_blocker.reset();
svector<lbool> values;
@ -2017,7 +2016,7 @@ namespace sat {
idx--;
}
reset_unmark(old_size);
if (m_config.m_minimize_core || m_config.m_minimize_core_partial) {
if (m_config.m_minimize_core) {
if (m_min_core_valid && m_min_core.size() < m_core.size()) {
IF_VERBOSE(1, verbose_stream() << "(sat.updating core " << m_min_core.size() << " " << m_core.size() << ")\n";);
m_core.reset();

12
src/smt/theory_arith_aux.h
View file

@ -1592,11 +1592,11 @@ namespace smt {
}
TRACE("opt", tout << "after traversing row:\nx_i: v" << x_i << ", x_j: v" << x_j << ", gain: " << max_gain << "\n";
tout << "best efforts: " << best_efforts << "\n";
display(tout););
tout << "best efforts: " << best_efforts << "\n";);
if (x_j == null_theory_var) {
TRACE("opt", tout << "row is " << (max ? "maximized" : "minimized") << "\n";);
TRACE("opt", tout << "row is " << (max ? "maximized" : "minimized") << "\n";
display_row(tout, r, true););
SASSERT(!maintain_integrality || valid_assignment());
SASSERT(satisfy_bounds());
result = OPTIMIZED;
@ -1772,7 +1772,7 @@ namespace smt {
SASSERT(satisfy_bounds());
SASSERT(!is_quasi_base(v));
if ((max && at_upper(v)) || (!max && at_lower(v))) {
TRACE("opt", tout << "At bound: " << mk_pp(e, get_manager()) << "...\n";);
TRACE("opt", display_var(tout << "At " << (max?"max: ":"min: ") << mk_pp(e, get_manager()) << " \n", v););
return AT_BOUND; // nothing to be done...
}
m_tmp_row.reset();
@ -1796,10 +1796,10 @@ namespace smt {
mk_bound_from_row(v, get_value(v), max ? B_UPPER : B_LOWER, m_tmp_row);
}
else if (r == UNBOUNDED) {
TRACE("opt", tout << "unbounded: " << mk_pp(e, get_manager()) << "...\n";);
TRACE("opt", display_var(tout << "unbounded: " << mk_pp(e, get_manager()) << "\n", v););
}
else {
TRACE("opt", tout << "not optimized: " << mk_pp(e, get_manager()) << "...\n";);
TRACE("opt", display_var(tout << "not optimized: " << mk_pp(e, get_manager()) << "\n", v););
}
return r;
}