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preparing for inf extension of arithmetic

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2013-10-31 02:02:37 -07:00
parent acc7aa1636
commit 0b65aa83e8
6 changed files with 83 additions and 34 deletions
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66
src/opt/optimize_objectives.cpp
View file

@ -43,9 +43,11 @@ Notes:
#include "optimize_objectives.h"
#include "opt_solver.h"
#include "arith_decl_plugin.h"
#include "smt_context.h"
namespace opt {
void optimize_objectives::set_cancel(bool f) {
m_cancel = true;
}
@ -62,50 +64,29 @@ namespace opt {
/*
Enumerate locally optimal assignments until fixedpoint.
*/
lbool optimize_objectives::basic_opt(app_ref_vector& objectives, vector<inf_eps>& values)
{
ast_manager& m = objectives.get_manager();
lbool optimize_objectives::basic_opt(app_ref_vector& objectives) {
arith_util autil(m);
s->reset_objectives();
values.reset();
m_lower.reset();
m_upper.reset();
// First check_sat call to initialize theories
lbool is_sat = s->check_sat(0, 0);
if (is_sat == l_false) {
if (is_sat != l_true) {
return is_sat;
}
opt_solver::scoped_push _push(*s);
opt_solver::toggle_objective _t(*s, true);
for (unsigned i = 0; i < objectives.size(); ++i) {
s->add_objective(objectives[i].get());
values.push_back(inf_eps(rational(-1),inf_rational(0)));
m_lower.push_back(inf_eps(rational(-1),inf_rational(0)));
m_upper.push_back(inf_eps(rational(1), inf_rational(0)));
}
is_sat = s->check_sat(0, 0);
while (is_sat == l_true && !m_cancel) {
set_max(values, s->get_objective_values());
IF_VERBOSE(1,
for (unsigned i = 0; i < values.size(); ++i) {
verbose_stream() << values[i] << " ";
}
verbose_stream() << "\n";);
expr_ref_vector disj(m);
expr_ref constraint(m);
for (unsigned i = 0; i < objectives.size(); ++i) {
inf_eps const& v = values[i];
disj.push_back(s->block_lower_bound(i, v));
}
constraint = m.mk_or(disj.size(), disj.c_ptr());
s->assert_expr(constraint);
is_sat = s->check_sat(0, 0);
is_sat = update_lower();
}
if (m_cancel || is_sat == l_undef) {
return l_undef;
@ -113,13 +94,40 @@ namespace opt {
return l_true;
}
lbool optimize_objectives::update_lower() {
lbool is_sat = s->check_sat(0, 0);
set_max(m_lower, s->get_objective_values());
IF_VERBOSE(1,
for (unsigned i = 0; i < m_lower.size(); ++i) {
verbose_stream() << m_lower[i] << " ";
}
verbose_stream() << "\n";);
expr_ref_vector disj(m);
expr_ref constraint(m);
for (unsigned i = 0; i < m_lower.size(); ++i) {
inf_eps const& v = m_lower[i];
disj.push_back(s->block_lower_bound(i, v));
}
constraint = m.mk_or(disj.size(), disj.c_ptr());
s->assert_expr(constraint);
return is_sat;
}
lbool optimize_objectives::update_upper() {
return l_undef;
}
/**
Takes solver with hard constraints added.
Returns an optimal assignment to objective functions.
*/
lbool optimize_objectives::operator()(opt_solver& solver, app_ref_vector& objectives, vector<inf_eps>& values) {
s = &solver;
return basic_opt(objectives, values);
lbool result = basic_opt(objectives);
values.reset();
values.append(m_lower);
return result;
}
}

8
src/opt/optimize_objectives.h
View file

@ -31,6 +31,8 @@ namespace opt {
ast_manager& m;
opt_solver* s;
volatile bool m_cancel;
vector<inf_eps> m_lower;
vector<inf_eps> m_upper;
public:
optimize_objectives(ast_manager& m): m(m), s(0), m_cancel(false) {}
@ -40,10 +42,14 @@ namespace opt {
private:
lbool basic_opt(app_ref_vector& objectives, vector<inf_eps>& values);
lbool basic_opt(app_ref_vector& objectives);
void set_max(vector<inf_eps>& dst, vector<inf_eps> const& src);
lbool update_lower();
lbool update_upper();
};
};