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enable pb solver

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2017-05-07 18:03:38 -07:00
parent b915f78281
commit c49550ff2d
5 changed files with 154 additions and 7 deletions
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3
src/sat/card_extension.cpp
View file

@ -49,6 +49,9 @@ namespace sat {
m_max_sum(0) {
for (unsigned i = 0; i < wlits.size(); ++i) {
m_wlits[i] = wlits[i];
if (m_max_sum + wlits[i].first < m_max_sum) {
throw default_exception("addition of pb coefficients overflows");
}
m_max_sum += wlits[i].first;
}
}

1
src/sat/sat_params.pyg
View file

@ -27,6 +27,7 @@ def_module_params('sat',
('drat.file', SYMBOL, '', 'file to dump DRAT proofs'),
('drat.check', BOOL, False, 'build up internal proof and check'),
('cardinality.solver', BOOL, False, 'use cardinality solver'),
('pb.solver', BOOL, False, 'use pb solver'),
('xor.solver', BOOL, False, 'use xor solver'),
('local_search_threads', UINT, 0, 'number of local search threads to find satisfiable solution'),
('local_search', BOOL, False, 'use local search instead of CDCL'),

3
src/sat/sat_solver/inc_sat_solver.cpp
View file

@ -216,7 +216,8 @@ public:
m_params.append(p);
sat_params p1(p);
m_params.set_bool("elim_vars", false);
m_params.set_bool("keep_cardinality_constraints", p1.cardinality_solver());
m_params.set_bool("keep_cardinality_constraints", p1.pb_solver() || p1.cardinality_solver());
m_params.set_bool("keep_pb_constraints", p1.pb_solver());
m_params.set_bool("xor_solver", p1.xor_solver());
m_solver.updt_params(m_params);
m_optimize_model = m_params.get_bool("optimize_model", false);

121
src/sat/tactic/goal2sat.cpp
View file

@ -419,6 +419,103 @@ struct goal2sat::imp {
}
}
typedef std::pair<unsigned, sat::literal> wliteral;
void check_unsigned(rational const& c) {
if (!c.is_unsigned()) {
throw default_exception("unsigned coefficient expected");
}
}
void convert_to_wlits(app* t, sat::literal_vector const& lits, svector<wliteral>& wlits) {
for (unsigned i = 0; i < lits.size(); ++i) {
rational c = pb.get_coeff(t, i);
check_unsigned(c);
wlits.push_back(std::make_pair(c.get_unsigned(), lits[i]));
}
}
void convert_pb_args(app* t, svector<wliteral>& wlits) {
sat::literal_vector lits;
convert_pb_args(t->get_num_args(), lits);
convert_to_wlits(t, lits, wlits);
}
void convert_pb_ge(app* t, bool root, bool sign) {
rational k = pb.get_k(t);
check_unsigned(k);
svector<wliteral> wlits;
convert_pb_args(t, wlits);
unsigned sz = m_result_stack.size();
if (root) {
m_result_stack.reset();
m_ext->add_pb_ge(sat::null_bool_var, wlits, k.get_unsigned());
}
else {
sat::bool_var v = m_solver.mk_var(true);
sat::literal lit(v, sign);
m_ext->add_pb_ge(v, wlits, k.get_unsigned());
TRACE("goal2sat", tout << "root: " << root << " lit: " << lit << "\n";);
m_result_stack.shrink(sz - t->get_num_args());
m_result_stack.push_back(lit);
}
}
void convert_pb_le(app* t, bool root, bool sign) {
rational k = pb.get_k(t);
k.neg();
svector<wliteral> wlits;
convert_pb_args(t, wlits);
for (unsigned i = 0; i < wlits.size(); ++i) {
wlits[i].second.neg();
k += rational(wlits[i].first);
}
check_unsigned(k);
unsigned sz = m_result_stack.size();
if (root) {
m_result_stack.reset();
m_ext->add_pb_ge(sat::null_bool_var, wlits, k.get_unsigned());
}
else {
sat::bool_var v = m_solver.mk_var(true);
sat::literal lit(v, sign);
m_ext->add_pb_ge(v, wlits, k.get_unsigned());
TRACE("goal2sat", tout << "root: " << root << " lit: " << lit << "\n";);
m_result_stack.shrink(sz - t->get_num_args());
m_result_stack.push_back(lit);
}
}
void convert_pb_eq(app* t, bool root, bool sign) {
rational k = pb.get_k(t);
SASSERT(k.is_unsigned());
svector<wliteral> wlits;
convert_pb_args(t, wlits);
sat::bool_var v1 = root ? sat::null_bool_var : m_solver.mk_var(true);
sat::bool_var v2 = root ? sat::null_bool_var : m_solver.mk_var(true);
m_ext->add_pb_ge(v1, wlits, k.get_unsigned());
k.neg();
for (unsigned i = 0; i < wlits.size(); ++i) {
wlits[i].second.neg();
k += rational(wlits[i].first);
}
check_unsigned(k);
m_ext->add_pb_ge(v2, wlits, k.get_unsigned());
if (root) {
m_result_stack.reset();
}
else {
sat::literal l1(v1, false), l2(v2, false);
sat::bool_var v = m_solver.mk_var();
sat::literal l(v, false);
mk_clause(~l, l1);
mk_clause(~l, l2);
mk_clause(~l1, ~l2, l);
m_result_stack.shrink(m_result_stack.size() - t->get_num_args());
m_result_stack.push_back(l);
}
}
void convert_at_least_k(app* t, rational k, bool root, bool sign) {
SASSERT(k.is_unsigned());
sat::literal_vector lits;
@ -529,16 +626,28 @@ struct goal2sat::imp {
convert_at_least_k(t, pb.get_k(t), root, sign);
break;
case OP_PB_LE:
SASSERT(pb.has_unit_coefficients(t));
convert_at_most_k(t, pb.get_k(t), root, sign);
if (pb.has_unit_coefficients(t)) {
convert_at_most_k(t, pb.get_k(t), root, sign);
}
else {
convert_pb_le(t, root, sign);
}
break;
case OP_PB_GE:
SASSERT(pb.has_unit_coefficients(t));
convert_at_least_k(t, pb.get_k(t), root, sign);
if (pb.has_unit_coefficients(t)) {
convert_at_least_k(t, pb.get_k(t), root, sign);
}
else {
convert_pb_ge(t, root, sign);
}
break;
case OP_PB_EQ:
SASSERT(pb.has_unit_coefficients(t));
convert_eq_k(t, pb.get_k(t), root, sign);
if (pb.has_unit_coefficients(t)) {
convert_eq_k(t, pb.get_k(t), root, sign);
}
else {
convert_pb_eq(t, root, sign);
}
break;
default:
UNREACHABLE();