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adding maxlex, delay mk_true() calls in goal2sat

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2019-01-24 21:36:40 -08:00
parent b4f4a1f316
commit d3d392da41
2 changed files with 100 additions and 16 deletions
src
opt
maxlex.cpp
sat/tactic
goal2sat.cpp

115
src/opt/maxlex.cpp
View file

@ -26,6 +26,10 @@ Author:
namespace opt {
bool is_maxlex(weights_t & _ws) {
// disable for now
#if true
return false;
#else
vector<rational> ws(_ws);
std::sort(ws.begin(), ws.end());
ws.reverse();
@ -38,6 +42,7 @@ namespace opt {
sum -= w;
}
return true;
#endif
}
class maxlex : public maxsmt_solver_base {
@ -131,21 +136,7 @@ namespace opt {
update_assignment(mdl);
}
public:
maxlex(maxsat_context& c, unsigned id, weights_t & ws, expr_ref_vector const& s):
maxsmt_solver_base(c, ws, s),
m(c.get_manager()),
m_c(c) {
// ensure that soft constraints are sorted with largest soft constraints first.
cmp_soft cmp;
std::sort(m_soft.begin(), m_soft.end(), cmp);
}
lbool operator()() override {
init();
lbool maxlex1() {
for (auto & soft : m_soft) {
if (soft.value == l_true) {
continue;
@ -169,6 +160,100 @@ namespace opt {
return l_true;
}
// try two literals per round.
// doesn't seem to make a difference based on sample test.
lbool maxlex2() {
unsigned sz = m_soft.size();
for (unsigned i = 0; i < sz; ++i) {
auto& soft = m_soft[i];
if (soft.value != l_undef) {
continue;
}
SASSERT(soft.value() == l_undef);
if (i + 1 == sz) {
expr* a = soft.s;
lbool is_sat = s().check_sat(1, &a);
switch (is_sat) {
case l_false:
set_value(soft, l_false);
update_bounds();
break;
case l_true:
update_assignment();
SASSERT(soft.value == l_true);
break;
case l_undef:
return l_undef;
}
}
else {
auto& soft2 = m_soft[i+1];
expr_ref_vector core(m);
expr* a = soft.s;
expr* b = soft2.s;
expr* asms[2] = { a, b };
lbool is_sat = s().check_sat(2, asms);
switch (is_sat) {
case l_true:
update_assignment();
SASSERT(soft.value == l_true);
SASSERT(soft2.value == l_true);
break;
case l_false:
s().get_unsat_core(core);
if (core.contains(b)) {
expr_ref not_b(mk_not(m, b), m);
asms[1] = not_b;
switch (s().check_sat(2, asms)) {
case l_true:
// a, b is unsat, a, not b is sat.
set_value(soft2, l_false);
update_assignment();
SASSERT(soft.value == l_true);
SASSERT(soft2.value == l_false);
break;
case l_false:
// a, b is unsat, a, not b is unsat -> a is unsat
// b is unsat, a, not b is unsat -> not a, not b
set_value(soft, l_false);
if (!core.contains(a)) {
set_value(soft2, l_false);
}
update_bounds();
break;
case l_undef:
return l_undef;
}
}
else {
set_value(soft, l_false);
update_bounds();
}
break;
case l_undef:
return l_undef;
}
}
}
return l_true;
}
public:
maxlex(maxsat_context& c, unsigned id, weights_t & ws, expr_ref_vector const& s):
maxsmt_solver_base(c, ws, s),
m(c.get_manager()),
m_c(c) {
// ensure that soft constraints are sorted with largest soft constraints first.
cmp_soft cmp;
std::sort(m_soft.begin(), m_soft.end(), cmp);
}
lbool operator()() override {
init();
return maxlex1();
}
void commit_assignment() override {
for (auto & soft : m_soft) {

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

@ -82,7 +82,6 @@ struct goal2sat::imp {
m_is_lemma(false) {
updt_params(p);
m_true = sat::null_bool_var;
mk_true();
}
void updt_params(params_ref const & p) {