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Instrument fu_malik to use the new SAT solver (WIP)

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This commit is contained in:
Anh-Dung Phan 2013-11-14 19:02:15 -08:00
parent d729e89a7b
commit 4be11f24e1
3 changed files with 73 additions and 19 deletions
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4
src/opt/core_maxsat.cpp
View file

@ -65,7 +65,7 @@ namespace opt {
for (unsigned i = 0; i < ans.size(); ++i) {
tout << mk_pp(ans[i].get(), m) << "\n";
});
IF_VERBOSE(1, verbose_stream() << "(maxsat.core sat: " << ans.size() << "\n";);
IF_VERBOSE(0, verbose_stream() << "(maxsat.core sat with lower bound: " << ans.size() << "\n";);
if (ans.size() > m_answer.size()) {
m_answer.reset();
m_answer.append(ans);
@ -92,7 +92,7 @@ namespace opt {
core_vars.insert(get_not(core[i]));
block_vars.remove(core[i]);
}
IF_VERBOSE(1, verbose_stream() << "(maxsat.core unsat (core size = " << core.size() << ")\n";);
IF_VERBOSE(0, verbose_stream() << "(maxsat.core unsat (core size = " << core.size() << ")\n";);
if (core.empty()) {
m_upper = m_answer.size();
return l_true;

74
src/opt/fu_malik.cpp
View file

@ -18,6 +18,11 @@ Notes:
--*/
#include "fu_malik.h"
#include "smtlogics/qfbv_tactic.h"
#include "tactic2solver.h"
#include "goal.h"
#include "probe.h"
#include "smt_context.h"
/**
\brief Fu & Malik procedure for MaxSAT. This procedure is based on
@ -37,25 +42,29 @@ namespace opt {
struct fu_malik::imp {
ast_manager& m;
solver& s;
ref<solver> m_s;
expr_ref_vector m_soft;
expr_ref_vector m_orig_soft;
expr_ref_vector m_aux;
expr_ref_vector m_assignment;
unsigned m_upper_size;
solver & m_original_solver;
bool m_use_new_bv_solver;
imp(ast_manager& m, solver& s, expr_ref_vector const& soft):
m(m),
s(s),
m_s(&s),
m_soft(soft),
m_orig_soft(soft),
m_aux(m),
m_assignment(m)
m_assignment(m),
m_original_solver(s),
m_use_new_bv_solver(false)
{
m_upper_size = m_soft.size() + 1;
}
solver& s() { return *m_s; }
/**
\brief One step of the Fu&Malik algorithm.
@ -73,18 +82,30 @@ namespace opt {
*/
lbool step() {
IF_VERBOSE(1, verbose_stream() << "(opt.max_sat step)\n";); // add some count, add some information of # of soft constraints still possibly sat.
IF_VERBOSE(0, verbose_stream() << "(opt.max_sat step " << m_soft.size() + 2 - m_upper_size << ")\n";);
expr_ref_vector assumptions(m), block_vars(m);
for (unsigned i = 0; i < m_soft.size(); ++i) {
assumptions.push_back(m.mk_not(m_aux[i].get()));
}
lbool is_sat = s.check_sat(assumptions.size(), assumptions.c_ptr());
lbool is_sat = s().check_sat(assumptions.size(), assumptions.c_ptr());
if (is_sat != l_false) {
return is_sat;
}
ptr_vector<expr> core;
s.get_unsat_core(core);
if (m_use_new_bv_solver) {
unsigned i = 0;
while (s().check_sat(core.size(), core.c_ptr()) != l_false) {
IF_VERBOSE(0, verbose_stream() << "(opt.max_sat get-unsat-core round " << i << ")\n";);
core.push_back(assumptions[i].get());
++i;
}
}
else {
s().get_unsat_core(core);
}
SASSERT(!core.empty());
// Update soft-constraints and aux_vars
for (unsigned i = 0; i < m_soft.size(); ++i) {
@ -101,9 +122,11 @@ namespace opt {
m_aux[i] = m.mk_fresh_const("aux", m.mk_bool_sort());
m_soft[i] = m.mk_or(m_soft[i].get(), block_var);
block_vars.push_back(block_var);
s.assert_expr(m.mk_or(m_soft[i].get(), m_aux[i].get()));
s().assert_expr(m.mk_or(m_soft[i].get(), m_aux[i].get()));
}
SASSERT (!block_vars.empty());
assert_at_most_one(block_vars);
IF_VERBOSE(0, verbose_stream() << "(opt.max_sat # of non-blocked soft constraints: " << m_soft.size() - block_vars.size() << ")\n";);
return l_false;
}
@ -111,7 +134,7 @@ namespace opt {
expr_ref has_one(m), has_zero(m), at_most_one(m);
mk_at_most_one(block_vars.size(), block_vars.c_ptr(), has_one, has_zero);
at_most_one = m.mk_or(has_one, has_zero);
s.assert_expr(at_most_one);
s().assert_expr(at_most_one);
}
void mk_at_most_one(unsigned n, expr* const * vars, expr_ref& has_one, expr_ref& has_zero) {
@ -129,15 +152,40 @@ namespace opt {
has_zero = m.mk_and(has_zero1, has_zero2);
}
}
void set_solver() {
solver& current_solver = s();
goal g(m, true, false);
unsigned num_assertions = current_solver.get_num_assertions();
for (unsigned i = 0; i < num_assertions; ++i) {
g.assert_expr(current_solver.get_assertion(i));
}
probe *p = mk_is_qfbv_probe();
bool all_bv = (*p)(g).is_true();
if (all_bv) {
opt_solver & os = opt_solver::to_opt(m_original_solver);
smt::context & ctx = os.get_context();
tactic* t = mk_qfbv_tactic(m, ctx.get_params());
// The new SAT solver hasn't supported unsat core yet
m_s = mk_tactic2solver(m, t);
SASSERT(m_s != &m_original_solver);
for (unsigned i = 0; i < num_assertions; ++i) {
m_s->assert_expr(current_solver.get_assertion(i));
}
m_use_new_bv_solver = true;
IF_VERBOSE(0, verbose_stream() << "Force to use the new BV solver." << std::endl;);
}
}
// TBD: bug when cancel flag is set, fu_malik returns is_sat == l_true instead of l_undef
lbool operator()() {
lbool is_sat = s.check_sat(0,0);
set_solver();
lbool is_sat = s().check_sat(0,0);
if (!m_soft.empty() && is_sat == l_true) {
solver::scoped_push _sp(s);
solver::scoped_push _sp(s());
for (unsigned i = 0; i < m_soft.size(); ++i) {
m_aux.push_back(m.mk_fresh_const("p", m.mk_bool_sort()));
s.assert_expr(m.mk_or(m_soft[i].get(), m_aux[i].get()));
s().assert_expr(m.mk_or(m_soft[i].get(), m_aux[i].get()));
}
lbool is_sat = l_true;
@ -150,7 +198,7 @@ namespace opt {
if (is_sat == l_true) {
// Get a list of satisfying m_soft
model_ref model;
s.get_model(model);
s().get_model(model);
m_assignment.reset();
for (unsigned i = 0; i < m_orig_soft.size(); ++i) {

14
src/tactic/smtlogics/qfbv_tactic.cpp
View file

@ -31,6 +31,15 @@ Notes:
#define MEMLIMIT 300
tactic * mk_new_sat_tactic(ast_manager & m) {
IF_VERBOSE(0, verbose_stream() << "Try to use the new SAT solver." << std::endl;);
tactic * new_sat = cond(mk_or(mk_produce_proofs_probe(), mk_produce_unsat_cores_probe()),
and_then(mk_simplify_tactic(m),
mk_smt_tactic()),
mk_sat_tactic(m));
return new_sat;
}
tactic * mk_qfbv_tactic(ast_manager & m, params_ref const & p) {
params_ref main_p;
main_p.set_bool("elim_and", true);
@ -85,10 +94,7 @@ tactic * mk_qfbv_tactic(ast_manager & m, params_ref const & p) {
tactic * new_sat = and_then(mk_simplify_tactic(m),
mk_smt_tactic());
#else
tactic * new_sat = cond(mk_or(mk_produce_proofs_probe(), mk_produce_unsat_cores_probe()),
and_then(mk_simplify_tactic(m),
mk_smt_tactic()),
mk_sat_tactic(m));
tactic * new_sat = mk_new_sat_tactic(m);
#endif
tactic * st = using_params(and_then(preamble_st,