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reorg sls

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This commit is contained in:
Nikolaj Bjorner 2024-07-05 16:16:01 -07:00
parent 8e482df62a
commit 5ebcc3e447
25 changed files with 1923 additions and 1107 deletions
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103
src/sat/sat_ddfw.cpp
View file

@ -33,8 +33,6 @@
namespace sat {
ddfw::~ddfw() {
for (auto& ci : m_clauses)
m_alloc.del_clause(ci.m_clause);
}
lbool ddfw::check(unsigned sz, literal const* assumptions, parallel* p) {
@ -63,13 +61,12 @@ namespace sat {
m_plugin->init_search();
m_steps_since_progress = 0;
unsigned steps = 0;
while (m_min_sz > 0 && m_steps_since_progress++ <= 1500000) {
save_best_values();
while (m_min_sz != 0 && m_steps_since_progress++ <= 1500000) {
if (should_reinit_weights()) do_reinit_weights();
else if (steps % 5000 == 0) shift_weights(), m_plugin->on_rescale();
else if (should_restart()) do_restart(), m_plugin->on_restart();
else if (do_flip<true>());
else if (do_literal_flip<true>());
else if (should_parallel_sync()) do_parallel_sync();
else shift_weights(), m_plugin->on_rescale();
++steps;
}
@ -78,7 +75,7 @@ namespace sat {
void ddfw::log() {
double sec = m_stopwatch.get_current_seconds();
double kflips_per_sec = (m_flips - m_last_flips) / (1000.0 * sec);
double kflips_per_sec = sec > 0 ? (m_flips - m_last_flips) / (1000.0 * sec) : 0.0;
if (m_last_flips == 0) {
IF_VERBOSE(1, verbose_stream() << "(sat.ddfw :unsat :models :kflips/sec :flips :restarts :reinits :unsat_vars :shifts";
if (m_par) verbose_stream() << " :par";
@ -112,10 +109,7 @@ namespace sat {
return false;
if (reward > 0 || (reward == 0 && m_rand(100) <= m_config.m_use_reward_zero_pct)) {
if (uses_plugin && is_external(v))
m_plugin->flip(v);
else
flip(v);
flip(v);
if (m_unsat.size() <= m_min_sz)
save_best_values();
return true;
@ -154,67 +148,36 @@ namespace sat {
return m_unsat_vars.elem_at(m_rand(m_unsat_vars.size()));
}
template<bool uses_plugin>
bool ddfw::do_literal_flip() {
double reward = 1;
return apply_flip<uses_plugin>(pick_literal_var<uses_plugin>(), reward);
}
/*
* Pick a random false literal from a satisfied clause such that
* the literal has zero break count and positive reward.
*/
template<bool uses_plugin>
bool_var ddfw::pick_literal_var() {
#if false
unsigned sz = m_clauses.size();
unsigned start = rand();
for (unsigned i = 0; i < 100; ++i) {
unsigned cl = (i + start) % sz;
if (m_unsat.contains(cl))
continue;
for (auto lit : *m_clauses[cl].m_clause) {
if (is_true(lit))
continue;
double r = uses_plugin ? plugin_reward(lit.var()) : reward(lit.var());
if (r < 0)
continue;
//verbose_stream() << "false " << r << " " << lit << "\n";
return lit.var();
}
}
#endif
return null_bool_var;
}
void ddfw::add(unsigned n, literal const* c) {
clause* cls = m_alloc.mk_clause(n, c, false);
unsigned idx = m_clauses.size();
m_clauses.push_back(clause_info(cls, m_config.m_init_clause_weight));
for (literal lit : *cls) {
m_clauses.push_back(clause_info(n, c, m_config.m_init_clause_weight));
for (literal lit : m_clauses.back().m_clause) {
m_use_list.reserve(2*(lit.var()+1));
m_vars.reserve(lit.var()+1);
m_use_list[lit.index()].push_back(idx);
}
}
sat::bool_var ddfw::add_var(bool is_internal) {
auto v = m_vars.size();
m_vars.reserve(v + 1);
m_vars[v].m_internal = is_internal;
return v;
}
/**
* Remove the last clause that was added
*/
void ddfw::del() {
auto& info = m_clauses.back();
for (literal lit : *info.m_clause)
for (literal lit : info.m_clause)
m_use_list[lit.index()].pop_back();
m_alloc.del_clause(info.m_clause);
m_clauses.pop_back();
if (m_unsat.contains(m_clauses.size()))
m_unsat.remove(m_clauses.size());
}
void ddfw::add(solver const& s) {
for (auto& ci : m_clauses)
m_alloc.del_clause(ci.m_clause);
m_clauses.reset();
m_use_list.reset();
m_num_non_binary_clauses = 0;
@ -295,6 +258,12 @@ namespace sat {
flatten_use_list();
}
void ddfw::reinit() {
add_assumptions();
init_clause_data();
flatten_use_list();
}
void ddfw::flatten_use_list() {
m_use_list_index.reset();
m_flat_use_list.reset();
@ -310,7 +279,7 @@ namespace sat {
literal lit = literal(v, !value(v));
literal nlit = ~lit;
SASSERT(is_true(lit));
for (unsigned cls_idx : use_list(*this, lit)) {
for (unsigned cls_idx : use_list(lit)) {
clause_info& ci = m_clauses[cls_idx];
ci.del(lit);
double w = ci.m_weight;
@ -318,7 +287,7 @@ namespace sat {
switch (ci.m_num_trues) {
case 0: {
m_unsat.insert_fresh(cls_idx);
clause const& c = get_clause(cls_idx);
auto const& c = get_clause(cls_idx);
for (literal l : c) {
inc_reward(l, w);
inc_make(l);
@ -333,7 +302,7 @@ namespace sat {
break;
}
}
for (unsigned cls_idx : use_list(*this, nlit)) {
for (unsigned cls_idx : use_list(nlit)) {
clause_info& ci = m_clauses[cls_idx];
double w = ci.m_weight;
// the clause used to have a single true (pivot) literal, now it has two.
@ -341,7 +310,7 @@ namespace sat {
switch (ci.m_num_trues) {
case 0: {
m_unsat.remove(cls_idx);
clause const& c = get_clause(cls_idx);
auto const& c = get_clause(cls_idx);
for (literal l : c) {
dec_reward(l, w);
dec_make(l);
@ -388,13 +357,13 @@ namespace sat {
for (unsigned v = 0; v < num_vars(); ++v) {
make_count(v) = 0;
reward(v) = 0;
}
}
m_unsat_vars.reset();
m_unsat.reset();
unsigned sz = m_clauses.size();
for (unsigned i = 0; i < sz; ++i) {
auto& ci = m_clauses[i];
clause const& c = get_clause(i);
auto const& c = get_clause(i);
ci.m_trues = 0;
ci.m_num_trues = 0;
for (literal lit : c)
@ -475,7 +444,7 @@ namespace sat {
void ddfw::save_best_values() {
if (m_unsat.size() < m_min_sz) {
if (m_unsat.size() < m_min_sz || m_unsat.empty()) {
m_steps_since_progress = 0;
if (m_unsat.size() < 50 || m_min_sz * 10 > m_unsat.size() * 11)
save_model();
@ -538,11 +507,11 @@ namespace sat {
unsigned ddfw::select_max_same_sign(unsigned cf_idx) {
auto& ci = m_clauses[cf_idx];
unsigned cl = UINT_MAX; // clause pointer to same sign, max weight satisfied clause.
clause const& c = *ci.m_clause;
auto const& c = ci.m_clause;
double max_weight = m_init_weight;
unsigned n = 1;
for (literal lit : c) {
for (unsigned cn_idx : use_list(*this, lit)) {
for (unsigned cn_idx : use_list(lit)) {
auto& cn = m_clauses[cn_idx];
if (select_clause(max_weight, cn, n)) {
cl = cn_idx;
@ -608,17 +577,15 @@ namespace sat {
std::ostream& ddfw::display(std::ostream& out) const {
unsigned num_cls = m_clauses.size();
for (unsigned i = 0; i < num_cls; ++i) {
out << get_clause(i) << " ";
out << get_clause(i) << " nt: ";
auto const& ci = m_clauses[i];
out << ci.m_num_trues << " " << ci.m_weight << "\n";
}
for (unsigned v = 0; v < num_vars(); ++v) {
out << v << ": " << reward(v) << "\n";
out << ci.m_num_trues << " w: " << ci.m_weight << "\n";
}
for (unsigned v = 0; v < num_vars(); ++v)
out << (is_true(literal(v, false)) ? "" : "-") << v << " rw: " << get_reward(v) << "\n";
out << "unsat vars: ";
for (bool_var v : m_unsat_vars) {
out << v << " ";
}
for (bool_var v : m_unsat_vars)
out << v << " ";
out << "\n";
return out;
}

73
src/sat/sat_ddfw.h
View file

@ -24,6 +24,7 @@
#include "util/rlimit.h"
#include "util/params.h"
#include "util/ema.h"
#include "util/sat_sls.h"
#include "sat/sat_clause.h"
#include "sat/sat_types.h"
@ -40,7 +41,6 @@ namespace sat {
virtual ~local_search_plugin() {}
virtual void init_search() = 0;
virtual void finish_search() = 0;
virtual void flip(bool_var v) = 0;
virtual double reward(bool_var v) = 0;
virtual void on_rescale() = 0;
virtual void on_save_model() = 0;
@ -48,30 +48,6 @@ namespace sat {
};
class ddfw : public i_local_search {
friend class arith::sls;
public:
struct clause_info {
clause_info(clause* cl, double init_weight): m_weight(init_weight), m_clause(cl) {}
double m_weight; // weight of clause
unsigned m_trues = 0; // set of literals that are true
unsigned m_num_trues = 0; // size of true set
clause* m_clause;
bool is_true() const { return m_num_trues > 0; }
void add(literal lit) { ++m_num_trues; m_trues += lit.index(); }
void del(literal lit) { SASSERT(m_num_trues > 0); --m_num_trues; m_trues -= lit.index(); }
};
class use_list {
ddfw& p;
unsigned i;
public:
use_list(ddfw& p, literal lit) :
p(p), i(lit.index()) {}
unsigned const* begin() { return p.m_flat_use_list.data() + p.m_use_list_index[i]; }
unsigned const* end() { return p.m_flat_use_list.data() + p.m_use_list_index[i + 1]; }
unsigned size() const { return p.m_use_list_index[i + 1] - p.m_use_list_index[i]; }
};
protected:
struct config {
@ -96,6 +72,7 @@ namespace sat {
struct var_info {
var_info() {}
bool m_internal = false;
bool m_value = false;
double m_reward = 0;
double m_last_reward = 0;
@ -107,8 +84,7 @@ namespace sat {
config m_config;
reslimit m_limit;
clause_allocator m_alloc;
svector<clause_info> m_clauses;
vector<clause_info> m_clauses;
literal_vector m_assumptions;
svector<var_info> m_vars; // var -> info
svector<double> m_probs; // var -> probability of flipping
@ -132,7 +108,7 @@ namespace sat {
stopwatch m_stopwatch;
parallel* m_par;
local_search_plugin* m_plugin = nullptr;
scoped_ptr<local_search_plugin> m_plugin = nullptr;
void flatten_use_list();
@ -142,17 +118,13 @@ namespace sat {
*/
inline double score(double r) { return r; }
inline unsigned num_vars() const { return m_vars.size(); }
inline unsigned& make_count(bool_var v) { return m_vars[v].m_make_count; }
inline bool& value(bool_var v) { return m_vars[v].m_value; }
inline bool value(bool_var v) const { return m_vars[v].m_value; }
inline double& reward(bool_var v) { return m_vars[v].m_reward; }
inline double reward(bool_var v) const { return m_vars[v].m_reward; }
inline double& reward(bool_var v) { return m_vars[v].m_reward; }
inline double plugin_reward(bool_var v) { return is_external(v) ? (m_vars[v].m_last_reward = m_plugin->reward(v)) : reward(v); }
@ -166,7 +138,7 @@ namespace sat {
inline bool is_true(literal lit) const { return value(lit.var()) != lit.sign(); }
inline clause const& get_clause(unsigned idx) const { return *m_clauses[idx].m_clause; }
inline sat::literal_vector const& get_clause(unsigned idx) const { return m_clauses[idx].m_clause; }
inline double get_weight(unsigned idx) const { return m_clauses[idx].m_weight; }
@ -203,11 +175,6 @@ namespace sat {
template<bool uses_plugin>
bool apply_flip(bool_var v, double reward);
template<bool uses_plugin>
bool do_literal_flip();
template<bool uses_plugin>
bool_var pick_literal_var();
void save_best_values();
void save_model();
@ -241,7 +208,7 @@ namespace sat {
void invariant();
void add(unsigned sz, literal const* c);
void del();
@ -257,7 +224,7 @@ namespace sat {
~ddfw() override;
void set(local_search_plugin* p) { m_plugin = p; }
void set_plugin(local_search_plugin* p) { m_plugin = p; }
lbool check(unsigned sz, literal const* assumptions, parallel* p) override;
@ -286,7 +253,7 @@ namespace sat {
// access clause information and state of Boolean search
indexed_uint_set& unsat_set() { return m_unsat; }
unsigned num_clauses() const { return m_clauses.size(); }
vector<clause_info> const& clauses() const { return m_clauses; }
clause_info& get_clause_info(unsigned idx) { return m_clauses[idx]; }
@ -294,7 +261,27 @@ namespace sat {
void flip(bool_var v);
use_list get_use_list(literal lit) { return use_list(*this, lit); }
inline double get_reward(bool_var v) const { return m_vars[v].m_reward; }
void add(unsigned sz, literal const* c);
sat::bool_var add_var(bool is_internal = true);
// is this a variable that was added during initialization?
bool is_initial_var(sat::bool_var v) const {
return m_vars.size() > v && !m_vars[v].m_internal;
}
void reinit();
inline unsigned num_vars() const { return m_vars.size(); }
std::initializer_list<unsigned> use_list(literal lit) {
unsigned i = lit.index();
auto const* b = m_flat_use_list.data() + m_use_list_index[i];
auto const* e = m_flat_use_list.data() + m_use_list_index[i + 1];
return std::initializer_list(b, e);
}
};
}

5
src/sat/sat_solver/sat_smt_solver.cpp
View file

@ -581,8 +581,9 @@ private:
void add_assumption(expr* a) {
init_goal2sat();
m_dep.insert(a, m_goal2sat.internalize(a));
get_euf()->add_assertion(a);
auto lit = m_goal2sat.internalize(a);
m_dep.insert(a, lit);
get_euf()->add_clause(1, &lit);
}
void internalize_assumptions(expr_ref_vector const& asms) {

2
src/sat/smt/CMakeLists.txt
View file

@ -3,7 +3,6 @@ z3_add_component(sat_smt
arith_axioms.cpp
arith_diagnostics.cpp
arith_internalize.cpp
arith_sls.cpp
arith_solver.cpp
arith_value.cpp
array_axioms.cpp
@ -22,7 +21,6 @@ z3_add_component(sat_smt
euf_ackerman.cpp
euf_internalize.cpp
euf_invariant.cpp
euf_local_search.cpp
euf_model.cpp
euf_proof.cpp
euf_proof_checker.cpp

642
src/sat/smt/arith_sls.cpp
View file

@ -1,642 +0,0 @@
/*++
Copyright (c) 2023 Microsoft Corporation
Module Name:
arith_local_search.cpp
Abstract:
Local search dispatch for SMT
Author:
Nikolaj Bjorner (nbjorner) 2023-02-07
--*/
#include "sat/sat_solver.h"
#include "sat/smt/arith_solver.h"
namespace arith {
sls::sls(solver& s):
s(s), m(s.m) {}
void sls::reset() {
m_bool_vars.reset();
m_vars.reset();
m_terms.reset();
}
void sls::save_best_values() {
for (unsigned v = 0; v < s.get_num_vars(); ++v)
m_vars[v].m_best_value = m_vars[v].m_value;
check_ineqs();
if (unsat().size() == 1) {
auto idx = *unsat().begin();
verbose_stream() << idx << "\n";
auto const& c = *m_bool_search->m_clauses[idx].m_clause;
verbose_stream() << c << "\n";
for (auto lit : c) {
bool_var bv = lit.var();
ineq* i = atom(bv);
if (i)
verbose_stream() << lit << ": " << *i << "\n";
}
verbose_stream() << "\n";
}
}
void sls::store_best_values() {
// first compute assignment to terms
// then update non-basic variables in tableau.
if (!unsat().empty())
return;
for (auto const& [t,v] : m_terms) {
int64_t val = 0;
lp::lar_term const& term = s.lp().get_term(t);
for (lp::lar_term::ival const& arg : term) {
auto t2 = arg.j();
auto w = s.lp().local_to_external(t2);
val += to_numeral(arg.coeff()) * m_vars[w].m_best_value;
}
m_vars[v].m_best_value = val;
}
for (unsigned v = 0; v < s.get_num_vars(); ++v) {
if (s.is_bool(v))
continue;
if (!s.lp().external_is_used(v))
continue;
int64_t new_value = m_vars[v].m_best_value;
s.ensure_column(v);
lp::lpvar vj = s.lp().external_to_local(v);
SASSERT(vj != lp::null_lpvar);
if (!s.lp().is_base(vj)) {
rational new_value_(new_value, rational::i64());
lp::impq val(new_value_, rational::zero());
s.lp().set_value_for_nbasic_column(vj, val);
}
}
lbool r = s.make_feasible();
VERIFY (!unsat().empty() || r == l_true);
#if 0
if (unsat().empty())
s.m_num_conflicts = s.get_config().m_arith_propagation_threshold;
#endif
auto check_bool_var = [&](sat::bool_var bv) {
auto* ineq = m_bool_vars.get(bv, nullptr);
if (!ineq)
return;
api_bound* b = nullptr;
s.m_bool_var2bound.find(bv, b);
if (!b)
return;
auto bound = b->get_value();
theory_var v = b->get_var();
if (s.get_phase(bv) == m_bool_search->get_model()[bv])
return;
switch (b->get_bound_kind()) {
case lp_api::lower_t:
verbose_stream() << "v" << v << " " << bound << " <= " << s.get_value(v) << " " << m_vars[v].m_best_value << "\n";
break;
case lp_api::upper_t:
verbose_stream() << "v" << v << " " << bound << " >= " << s.get_value(v) << " " << m_vars[v].m_best_value << "\n";
break;
}
int64_t value = 0;
for (auto const& [coeff, v] : ineq->m_args) {
value += coeff * m_vars[v].m_best_value;
}
ineq->m_args_value = value;
verbose_stream() << *ineq << " dtt " << dtt(false, *ineq) << " phase " << s.get_phase(bv) << " model " << m_bool_search->get_model()[bv] << "\n";
for (auto const& [coeff, v] : ineq->m_args)
verbose_stream() << "v" << v << " := " << m_vars[v].m_best_value << "\n";
s.display(verbose_stream());
display(verbose_stream());
UNREACHABLE();
exit(0);
};
if (unsat().empty()) {
for (bool_var v = 0; v < s.s().num_vars(); ++v)
check_bool_var(v);
}
}
void sls::set(sat::ddfw* d) {
m_bool_search = d;
reset();
m_bool_vars.reserve(s.s().num_vars());
add_vars();
for (unsigned i = 0; i < d->num_clauses(); ++i)
for (sat::literal lit : *d->get_clause_info(i).m_clause)
init_bool_var(lit.var());
for (unsigned v = 0; v < s.s().num_vars(); ++v)
init_bool_var_assignment(v);
d->set(this);
}
// distance to true
int64_t sls::dtt(bool sign, int64_t args, ineq const& ineq) const {
switch (ineq.m_op) {
case ineq_kind::LE:
if (sign) {
if (args <= ineq.m_bound)
return ineq.m_bound - args + 1;
return 0;
}
if (args <= ineq.m_bound)
return 0;
return args - ineq.m_bound;
case ineq_kind::EQ:
if (sign) {
if (args == ineq.m_bound)
return 1;
return 0;
}
if (args == ineq.m_bound)
return 0;
return 1;
case ineq_kind::NE:
if (sign) {
if (args == ineq.m_bound)
return 0;
return 1;
}
if (args == ineq.m_bound)
return 1;
return 0;
case ineq_kind::LT:
if (sign) {
if (args < ineq.m_bound)
return ineq.m_bound - args;
return 0;
}
if (args < ineq.m_bound)
return 0;
return args - ineq.m_bound + 1;
default:
UNREACHABLE();
return 0;
}
}
//
// dtt is high overhead. It walks ineq.m_args
// m_vars[w].m_value can be computed outside and shared among calls
// different data-structures for storing coefficients
//
int64_t sls::dtt(bool sign, ineq const& ineq, var_t v, int64_t new_value) const {
for (auto const& [coeff, w] : ineq.m_args)
if (w == v)
return dtt(sign, ineq.m_args_value + coeff * (new_value - m_vars[v].m_value), ineq);
return 1;
}
int64_t sls::dtt(bool sign, ineq const& ineq, int64_t coeff, int64_t old_value, int64_t new_value) const {
return dtt(sign, ineq.m_args_value + coeff * (new_value - old_value), ineq);
}
bool sls::cm(bool old_sign, ineq const& ineq, var_t v, int64_t& new_value) {
for (auto const& [coeff, w] : ineq.m_args)
if (w == v)
return cm(old_sign, ineq, v, coeff, new_value);
return false;
}
bool sls::cm(bool old_sign, ineq const& ineq, var_t v, int64_t coeff, int64_t& new_value) {
SASSERT(ineq.is_true() != old_sign);
VERIFY(ineq.is_true() != old_sign);
auto bound = ineq.m_bound;
auto argsv = ineq.m_args_value;
bool solved = false;
int64_t delta = argsv - bound;
auto make_eq = [&]() {
SASSERT(delta != 0);
if (delta < 0)
new_value = value(v) + (abs(delta) + abs(coeff) - 1) / coeff;
else
new_value = value(v) - (delta + abs(coeff) - 1) / coeff;
solved = argsv + coeff * (new_value - value(v)) == bound;
if (!solved && abs(coeff) == 1) {
verbose_stream() << "did not solve equality " << ineq << " for " << v << "\n";
verbose_stream() << new_value << " " << value(v) << " delta " << delta << " lhs " << (argsv + coeff * (new_value - value(v))) << " bound " << bound << "\n";
UNREACHABLE();
}
return solved;
};
auto make_diseq = [&]() {
if (delta >= 0)
delta++;
else
delta--;
new_value = value(v) + (abs(delta) + abs(coeff) - 1) / coeff;
VERIFY(argsv + coeff * (new_value - value(v)) != bound);
return true;
};
if (!old_sign) {
switch (ineq.m_op) {
case ineq_kind::LE:
// args <= bound -> args > bound
SASSERT(argsv <= bound);
SASSERT(delta <= 0);
--delta;
new_value = value(v) + (abs(delta) + abs(coeff) - 1) / coeff;
VERIFY(argsv + coeff * (new_value - value(v)) > bound);
return true;
case ineq_kind::LT:
// args < bound -> args >= bound
SASSERT(argsv <= ineq.m_bound);
SASSERT(delta <= 0);
new_value = value(v) + (abs(delta) + abs(coeff) - 1) / coeff;
VERIFY(argsv + coeff * (new_value - value(v)) >= bound);
return true;
case ineq_kind::EQ:
return make_diseq();
case ineq_kind::NE:
return make_eq();
default:
UNREACHABLE();
break;
}
}
else {
switch (ineq.m_op) {
case ineq_kind::LE:
SASSERT(argsv > ineq.m_bound);
SASSERT(delta > 0);
new_value = value(v) - (delta + abs(coeff) - 1) / coeff;
VERIFY(argsv + coeff * (new_value - value(v)) <= bound);
return true;
case ineq_kind::LT:
SASSERT(argsv >= ineq.m_bound);
SASSERT(delta >= 0);
++delta;
new_value = value(v) - (abs(delta) + abs(coeff) - 1) / coeff;
VERIFY(argsv + coeff * (new_value - value(v)) < bound);
return true;
case ineq_kind::NE:
return make_diseq();
case ineq_kind::EQ:
return make_eq();
default:
UNREACHABLE();
break;
}
}
return false;
}
// flip on the first positive score
// it could be changed to flip on maximal positive score
// or flip on maximal non-negative score
// or flip on first non-negative score
bool sls::flip(bool sign, ineq const& ineq) {
int64_t new_value;
auto v = ineq.m_var_to_flip;
if (v == UINT_MAX) {
IF_VERBOSE(1, verbose_stream() << "no var to flip\n");
return false;
}
if (!cm(sign, ineq, v, new_value)) {
verbose_stream() << "no critical move for " << v << "\n";
return false;
}
update(v, new_value);
return true;
}
//
// dscore(op) = sum_c (dts(c,alpha) - dts(c,alpha_after)) * weight(c)
// TODO - use cached dts instead of computed dts
// cached dts has to be updated when the score of literals are updated.
//
double sls::dscore(var_t v, int64_t new_value) const {
double score = 0;
auto const& vi = m_vars[v];
for (auto const& [coeff, bv] : vi.m_bool_vars) {
sat::literal lit(bv, false);
for (auto cl : m_bool_search->get_use_list(lit))
score += (compute_dts(cl) - dts(cl, v, new_value)) * m_bool_search->get_weight(cl);
for (auto cl : m_bool_search->get_use_list(~lit))
score += (compute_dts(cl) - dts(cl, v, new_value)) * m_bool_search->get_weight(cl);
}
return score;
}
//
// cm_score is costly. It involves several cache misses.
// Note that
// - m_bool_search->get_use_list(lit).size() is "often" 1 or 2
// - dtt_old can be saved
//
int sls::cm_score(var_t v, int64_t new_value) {
int score = 0;
auto& vi = m_vars[v];
int64_t old_value = vi.m_value;
for (auto const& [coeff, bv] : vi.m_bool_vars) {
auto const& ineq = *atom(bv);
bool old_sign = sign(bv);
int64_t dtt_old = dtt(old_sign, ineq);
int64_t dtt_new = dtt(old_sign, ineq, coeff, old_value, new_value);
if ((dtt_old == 0) == (dtt_new == 0))
continue;
sat::literal lit(bv, old_sign);
if (dtt_old == 0)
// flip from true to false
lit.neg();
// lit flips form false to true:
for (auto cl : m_bool_search->get_use_list(lit)) {
auto const& clause = get_clause_info(cl);
if (!clause.is_true())
++score;
}
// ignore the situation where clause contains multiple literals using v
for (auto cl : m_bool_search->get_use_list(~lit)) {
auto const& clause = get_clause_info(cl);
if (clause.m_num_trues == 1)
--score;
}
}
return score;
}
int64_t sls::compute_dts(unsigned cl) const {
int64_t d(1), d2;
bool first = true;
for (auto a : get_clause(cl)) {
auto const* ineq = atom(a.var());
if (!ineq)
continue;
d2 = dtt(a.sign(), *ineq);
if (first)
d = d2, first = false;
else
d = std::min(d, d2);
if (d == 0)
break;
}
return d;
}
int64_t sls::dts(unsigned cl, var_t v, int64_t new_value) const {
int64_t d(1), d2;
bool first = true;
for (auto lit : get_clause(cl)) {
auto const* ineq = atom(lit.var());
if (!ineq)
continue;
d2 = dtt(lit.sign(), *ineq, v, new_value);
if (first)
d = d2, first = false;
else
d = std::min(d, d2);
if (d == 0)
break;
}
return d;
}
void sls::update(var_t v, int64_t new_value) {
auto& vi = m_vars[v];
auto old_value = vi.m_value;
for (auto const& [coeff, bv] : vi.m_bool_vars) {
auto& ineq = *atom(bv);
bool old_sign = sign(bv);
sat::literal lit(bv, old_sign);
SASSERT(is_true(lit));
ineq.m_args_value += coeff * (new_value - old_value);
int64_t dtt_new = dtt(old_sign, ineq);
if (dtt_new != 0)
m_bool_search->flip(bv);
SASSERT(dtt(sign(bv), ineq) == 0);
}
vi.m_value = new_value;
}
void sls::add_vars() {
SASSERT(m_vars.empty());
for (unsigned v = 0; v < s.get_num_vars(); ++v) {
int64_t value = s.is_registered_var(v) ? to_numeral(s.get_ivalue(v).x) : 0;
auto k = s.is_int(v) ? sls::var_kind::INT : sls::var_kind::REAL;
m_vars.push_back({ value, value, k, {} });
}
}
sls::ineq& sls::new_ineq(ineq_kind op, int64_t const& bound) {
auto* i = alloc(ineq);
i->m_bound = bound;
i->m_op = op;
return *i;
}
void sls::add_arg(sat::bool_var bv, ineq& ineq, int64_t const& c, var_t v) {
ineq.m_args.push_back({ c, v });
ineq.m_args_value += c * value(v);
m_vars[v].m_bool_vars.push_back({ c, bv});
}
int64_t sls::to_numeral(rational const& r) {
if (r.is_int64())
return r.get_int64();
return 0;
}
void sls::add_args(sat::bool_var bv, ineq& ineq, lp::lpvar t, theory_var v, int64_t sign) {
if (s.lp().column_has_term(t)) {
lp::lar_term const& term = s.lp().get_term(t);
m_terms.push_back({t,v});
for (lp::lar_term::ival arg : term) {
auto t2 = arg.j();
auto w = s.lp().local_to_external(t2);
add_arg(bv, ineq, sign * to_numeral(arg.coeff()), w);
}
}
else
add_arg(bv, ineq, sign, s.lp().local_to_external(t));
}
void sls::init_bool_var(sat::bool_var bv) {
if (m_bool_vars.get(bv, nullptr))
return;
api_bound* b = nullptr;
s.m_bool_var2bound.find(bv, b);
if (b) {
auto t = b->column_index();
rational bound = b->get_value();
bool should_minus = false;
sls::ineq_kind op;
should_minus = b->get_bound_kind() == lp_api::bound_kind::lower_t;
op = sls::ineq_kind::LE;
if (should_minus)
bound.neg();
auto& ineq = new_ineq(op, to_numeral(bound));
add_args(bv, ineq, t, b->get_var(), should_minus ? -1 : 1);
m_bool_vars.set(bv, &ineq);
m_bool_search->set_external(bv);
return;
}
expr* e = s.bool_var2expr(bv);
expr* l = nullptr, * r = nullptr;
if (e && m.is_eq(e, l, r) && s.a.is_int_real(l)) {
theory_var u = s.get_th_var(l);
theory_var v = s.get_th_var(r);
lp::lpvar tu = s.get_column(u);
lp::lpvar tv = s.get_column(v);
auto& ineq = new_ineq(sls::ineq_kind::EQ, 0);
add_args(bv, ineq, tu, u, 1);
add_args(bv, ineq, tv, v, -1);
m_bool_vars.set(bv, &ineq);
m_bool_search->set_external(bv);
return;
}
}
void sls::init_bool_var_assignment(sat::bool_var v) {
auto* ineq = m_bool_vars.get(v, nullptr);
if (ineq && is_true(sat::literal(v, false)) != (dtt(false, *ineq) == 0))
m_bool_search->flip(v);
}
void sls::init_search() {
on_restart();
}
void sls::finish_search() {
store_best_values();
}
void sls::flip(sat::bool_var v) {
sat::literal lit(v, !sign(v));
SASSERT(!is_true(lit));
auto const* ineq = atom(v);
if (!ineq)
IF_VERBOSE(0, verbose_stream() << "no inequality for variable " << v << "\n");
if (!ineq)
return;
SASSERT(ineq->is_true() == lit.sign());
flip(sign(v), *ineq);
}
double sls::reward(sat::bool_var v) {
if (m_dscore_mode)
return dscore_reward(v);
else
return dtt_reward(v);
}
double sls::dtt_reward(sat::bool_var bv0) {
bool sign0 = sign(bv0);
auto* ineq = atom(bv0);
if (!ineq)
return -1;
int64_t new_value;
double max_result = -1;
for (auto const & [coeff, x] : ineq->m_args) {
if (!cm(sign0, *ineq, x, coeff, new_value))
continue;
double result = 0;
auto old_value = m_vars[x].m_value;
for (auto const& [coeff, bv] : m_vars[x].m_bool_vars) {
result += m_bool_search->reward(bv);
continue;
bool old_sign = sign(bv);
auto dtt_old = dtt(old_sign, *atom(bv));
auto dtt_new = dtt(old_sign, *atom(bv), coeff, old_value, new_value);
if ((dtt_new == 0) != (dtt_old == 0))
result += m_bool_search->reward(bv);
}
if (result > max_result) {
max_result = result;
ineq->m_var_to_flip = x;
}
}
return max_result;
}
double sls::dscore_reward(sat::bool_var bv) {
m_dscore_mode = false;
bool old_sign = sign(bv);
sat::literal litv(bv, old_sign);
auto* ineq = atom(bv);
if (!ineq)
return 0;
SASSERT(ineq->is_true() != old_sign);
int64_t new_value;
for (auto const& [coeff, v] : ineq->m_args) {
double result = 0;
if (cm(old_sign, *ineq, v, coeff, new_value))
result = dscore(v, new_value);
// just pick first positive, or pick a max?
if (result > 0) {
ineq->m_var_to_flip = v;
return result;
}
}
return 0;
}
// switch to dscore mode
void sls::on_rescale() {
m_dscore_mode = true;
}
void sls::on_save_model() {
save_best_values();
}
void sls::on_restart() {
for (unsigned v = 0; v < s.s().num_vars(); ++v)
init_bool_var_assignment(v);
check_ineqs();
}
void sls::check_ineqs() {
auto check_bool_var = [&](sat::bool_var bv) {
auto const* ineq = atom(bv);
if (!ineq)
return;
int64_t d = dtt(sign(bv), *ineq);
sat::literal lit(bv, sign(bv));
if (is_true(lit) != (d == 0)) {
verbose_stream() << "invalid assignment " << bv << " " << *ineq << "\n";
}
VERIFY(is_true(lit) == (d == 0));
};
for (unsigned v = 0; v < s.get_num_vars(); ++v)
check_bool_var(v);
}
std::ostream& sls::display(std::ostream& out) const {
for (bool_var bv = 0; bv < s.s().num_vars(); ++bv) {
auto const* ineq = atom(bv);
if (!ineq)
continue;
out << bv << " " << *ineq << "\n";
}
for (unsigned v = 0; v < s.get_num_vars(); ++v) {
if (s.is_bool(v))
continue;
out << "v" << v << " := " << m_vars[v].m_value << " " << m_vars[v].m_best_value << "\n";
}
return out;
}
}

170
src/sat/smt/arith_sls.h
View file

@ -1,170 +0,0 @@
/*++
Copyright (c) 2020 Microsoft Corporation
Module Name:
arith_local_search.h
Abstract:
Theory plugin for arithmetic local search
Author:
Nikolaj Bjorner (nbjorner) 2020-09-08
--*/
#pragma once
#include "util/obj_pair_set.h"
#include "ast/ast_trail.h"
#include "ast/arith_decl_plugin.h"
#include "math/lp/indexed_value.h"
#include "math/lp/lar_solver.h"
#include "math/lp/nla_solver.h"
#include "math/lp/lp_types.h"
#include "math/lp/lp_api.h"
#include "math/polynomial/algebraic_numbers.h"
#include "math/polynomial/polynomial.h"
#include "sat/smt/sat_th.h"
#include "sat/sat_ddfw.h"
namespace arith {
class solver;
// local search portion for arithmetic
class sls : public sat::local_search_plugin {
enum class ineq_kind { EQ, LE, LT, NE };
enum class var_kind { INT, REAL };
typedef unsigned var_t;
typedef unsigned atom_t;
struct config {
double cb = 0.0;
unsigned L = 20;
unsigned t = 45;
unsigned max_no_improve = 500000;
double sp = 0.0003;
};
struct stats {
unsigned m_num_flips = 0;
};
public:
// encode args <= bound, args = bound, args < bound
struct ineq {
vector<std::pair<int64_t, var_t>> m_args;
ineq_kind m_op = ineq_kind::LE;
int64_t m_bound;
int64_t m_args_value;
unsigned m_var_to_flip = UINT_MAX;
bool is_true() const {
switch (m_op) {
case ineq_kind::LE:
return m_args_value <= m_bound;
case ineq_kind::EQ:
return m_args_value == m_bound;
case ineq_kind::NE:
return m_args_value != m_bound;
default:
return m_args_value < m_bound;
}
}
std::ostream& display(std::ostream& out) const {
bool first = true;
for (auto const& [c, v] : m_args)
out << (first ? "" : " + ") << c << " * v" << v, first = false;
switch (m_op) {
case ineq_kind::LE:
return out << " <= " << m_bound << "(" << m_args_value << ")";
case ineq_kind::EQ:
return out << " == " << m_bound << "(" << m_args_value << ")";
case ineq_kind::NE:
return out << " != " << m_bound << "(" << m_args_value << ")";
default:
return out << " < " << m_bound << "(" << m_args_value << ")";
}
}
};
private:
struct var_info {
int64_t m_value;
int64_t m_best_value;
var_kind m_kind = var_kind::INT;
svector<std::pair<int64_t, sat::bool_var>> m_bool_vars;
};
solver& s;
ast_manager& m;
sat::ddfw* m_bool_search = nullptr;
stats m_stats;
config m_config;
scoped_ptr_vector<ineq> m_bool_vars;
vector<var_info> m_vars;
svector<std::pair<lp::lpvar, euf::theory_var>> m_terms;
bool m_dscore_mode = false;
indexed_uint_set& unsat() { return m_bool_search->unsat_set(); }
unsigned num_clauses() const { return m_bool_search->num_clauses(); }
sat::clause& get_clause(unsigned idx) { return *get_clause_info(idx).m_clause; }
sat::clause const& get_clause(unsigned idx) const { return *get_clause_info(idx).m_clause; }
sat::ddfw::clause_info& get_clause_info(unsigned idx) { return m_bool_search->get_clause_info(idx); }
sat::ddfw::clause_info const& get_clause_info(unsigned idx) const { return m_bool_search->get_clause_info(idx); }
bool is_true(sat::literal lit) { return lit.sign() != m_bool_search->get_value(lit.var()); }
bool sign(sat::bool_var v) const { return !m_bool_search->get_value(v); }
void reset();
ineq* atom(sat::bool_var bv) const { return m_bool_vars[bv]; }
bool flip(bool sign, ineq const& ineq);
int64_t dtt(bool sign, ineq const& ineq) const { return dtt(sign, ineq.m_args_value, ineq); }
int64_t dtt(bool sign, int64_t args_value, ineq const& ineq) const;
int64_t dtt(bool sign, ineq const& ineq, var_t v, int64_t new_value) const;
int64_t dtt(bool sign, ineq const& ineq, int64_t coeff, int64_t old_value, int64_t new_value) const;
int64_t dts(unsigned cl, var_t v, int64_t new_value) const;
int64_t compute_dts(unsigned cl) const;
bool cm(bool sign, ineq const& ineq, var_t v, int64_t& new_value);
bool cm(bool sign, ineq const& ineq, var_t v, int64_t coeff, int64_t& new_value);
int cm_score(var_t v, int64_t new_value);
void update(var_t v, int64_t new_value);
double dscore_reward(sat::bool_var v);
double dtt_reward(sat::bool_var v);
double dscore(var_t v, int64_t new_value) const;
void save_best_values();
void store_best_values();
void add_vars();
sls::ineq& new_ineq(ineq_kind op, int64_t const& bound);
void add_arg(sat::bool_var bv, ineq& ineq, int64_t const& c, var_t v);
void add_args(sat::bool_var bv, ineq& ineq, lp::lpvar j, euf::theory_var v, int64_t sign);
void init_bool_var(sat::bool_var v);
void init_bool_var_assignment(sat::bool_var v);
int64_t value(var_t v) const { return m_vars[v].m_value; }
int64_t to_numeral(rational const& r);
void check_ineqs();
std::ostream& display(std::ostream& out) const;
public:
sls(solver& s);
~sls() override {}
void set(sat::ddfw* d);
void init_search() override;
void finish_search() override;
void flip(sat::bool_var v) override;
double reward(sat::bool_var v) override;
void on_rescale() override;
void on_save_model() override;
void on_restart() override;
};
inline std::ostream& operator<<(std::ostream& out, sls::ineq const& ineq) {
return ineq.display(out);
}
}

1
src/sat/smt/arith_solver.cpp
View file

@ -24,7 +24,6 @@ namespace arith {
solver::solver(euf::solver& ctx, theory_id id) :
th_euf_solver(ctx, symbol("arith"), id),
m_model_eqs(DEFAULT_HASHTABLE_INITIAL_CAPACITY, var_value_hash(*this), var_value_eq(*this)),
m_local_search(*this),
m_resource_limit(*this),
m_bp(*this, m_implied_bounds),
a(m),

5
src/sat/smt/arith_solver.h
View file

@ -28,7 +28,6 @@ Author:
#include "math/polynomial/algebraic_numbers.h"
#include "math/polynomial/polynomial.h"
#include "sat/smt/sat_th.h"
#include "sat/smt/arith_sls.h"
#include "sat/sat_ddfw.h"
namespace euf {
@ -186,8 +185,6 @@ namespace arith {
coeffs().pop_back();
}
};
sls m_local_search;
typedef vector<std::pair<rational, lpvar>> var_coeffs;
vector<rational> m_columns;
@ -518,8 +515,6 @@ namespace arith {
bool enable_ackerman_axioms(euf::enode* n) const override { return !a.is_add(n->get_expr()); }
bool has_unhandled() const override { return m_not_handled != nullptr; }
void set_bool_search(sat::ddfw* ddfw) override { m_local_search.set(ddfw); }
// bounds and equality propagation callbacks
lp::lar_solver& lp() { return *m_solver; }
lp::lar_solver const& lp() const { return *m_solver; }

6
src/sat/smt/euf_internalize.cpp
View file

@ -525,8 +525,8 @@ namespace euf {
return n;
}
void solver::add_assertion(expr* f) {
m_assertions.push_back(f);
m_trail.push(push_back_vector(m_assertions));
void solver::add_clause(unsigned n, sat::literal const* lits) {
m_top_level_clauses.push_back(sat::literal_vector(n, lits));
m_trail.push(push_back_vector(m_top_level_clauses));
}
}

50
src/sat/smt/euf_local_search.cpp
View file

@ -1,50 +0,0 @@
/*++
Copyright (c) 2020 Microsoft Corporation
Module Name:
euf_local_search.cpp
Abstract:
Local search dispatch for SMT
Author:
Nikolaj Bjorner (nbjorner) 2023-02-07
--*/
#include "sat/sat_solver.h"
#include "sat/sat_ddfw.h"
#include "sat/smt/euf_solver.h"
namespace euf {
lbool solver::local_search(bool_vector& phase) {
scoped_limits scoped_rl(m.limit());
sat::ddfw bool_search;
bool_search.reinit(s(), phase);
bool_search.updt_params(s().params());
bool_search.set_seed(rand());
scoped_rl.push_child(&(bool_search.rlimit()));
for (auto* th : m_solvers)
th->set_bool_search(&bool_search);
bool_search.check(0, nullptr, nullptr);
auto const& mdl = bool_search.get_model();
for (unsigned i = 0; i < mdl.size(); ++i)
phase[i] = mdl[i] == l_true;
if (bool_search.unsat_set().empty()) {
enable_trace("arith");
enable_trace("sat");
enable_trace("euf");
TRACE("sat", s().display(tout));
}
return bool_search.unsat_set().empty() ? l_true : l_undef;
}
}

1
src/sat/smt/euf_solver.cpp
View file

@ -55,7 +55,6 @@ namespace euf {
m_smt_proof_checker(m, p),
m_clause(m),
m_expr_args(m),
m_assertions(m),
m_values(m)
{
updt_params(p);

19
src/sat/smt/euf_solver.h
View file

@ -100,15 +100,6 @@ namespace euf {
scope(unsigned l) : m_var_lim(l) {}
};
struct local_search_config {
double cb = 0.0;
unsigned L = 20;
unsigned t = 45;
unsigned max_no_improve = 500000;
double sp = 0.0003;
};
size_t* to_ptr(sat::literal l) { return TAG(size_t*, reinterpret_cast<size_t*>((size_t)(l.index() << 4)), 1); }
size_t* to_ptr(size_t jst) { return TAG(size_t*, reinterpret_cast<size_t*>(jst), 2); }
bool is_literal(size_t* p) const { return GET_TAG(p) == 1; }
@ -127,7 +118,6 @@ namespace euf {
sat::sat_internalizer& si;
relevancy m_relevancy;
smt_params m_config;
local_search_config m_ls_config;
euf::egraph m_egraph;
trail_stack m_trail;
stats m_stats;
@ -174,7 +164,7 @@ namespace euf {
symbol m_smt = symbol("smt");
expr_ref_vector m_clause;
expr_ref_vector m_expr_args;
expr_ref_vector m_assertions;
vector<sat::literal_vector> m_top_level_clauses;
// internalization
@ -356,7 +346,6 @@ namespace euf {
void add_assumptions(sat::literal_set& assumptions) override;
bool tracking_assumptions() override;
std::string reason_unknown() override { return m_reason_unknown; }
lbool local_search(bool_vector& phase) override;
void propagate(literal lit, ext_justification_idx idx);
bool propagate(enode* a, enode* b, ext_justification_idx idx);
@ -485,8 +474,10 @@ namespace euf {
bool enable_ackerman_axioms(expr* n) const;
bool is_fixed(euf::enode* n, expr_ref& val, sat::literal_vector& explain);
void add_assertion(expr* f);
expr_ref_vector const& get_assertions() { return m_assertions; }
// void add_assertion(expr* f);
// expr_ref_vector const& get_assertions() { return m_assertions; }
void add_clause(unsigned n, sat::literal const* lits);
vector <sat::literal_vector> const& top_level_clauses() const { return m_top_level_clauses; }
model_ref get_sls_model();
// relevancy

232
src/sat/smt/sls_solver.cpp
View file

@ -17,8 +17,7 @@ Author:
#include "sat/smt/sls_solver.h"
#include "sat/smt/euf_solver.h"
#include "ast/sls/sls_smt.h"
namespace sls {
@ -38,14 +37,14 @@ namespace sls {
}
void solver::finalize() {
if (!m_completed && m_sls) {
m_sls->cancel();
m_thread.join();
m_sls->collect_statistics(m_st);
m_sls = nullptr;
m_shared = nullptr;
if (!m_completed && m_ddfw) {
m_ddfw->rlimit().cancel();
m_thread.join();
m_ddfw->collect_statistics(m_st);
m_ddfw = nullptr;
m_slsm = nullptr;
m_units = nullptr;
m_smt_plugin = nullptr;
m_units.reset();
}
}
@ -59,107 +58,162 @@ namespace sls {
return false;
}
bool solver::is_unit(expr* e) {
if (!e)
return false;
m.is_not(e, e);
if (is_uninterp_const(e))
return true;
bv_util bu(m);
expr* s;
if (bu.is_bit2bool(e, s))
return is_uninterp_const(s);
return false;
}
void solver::pop_core(unsigned n) {
for (; m_trail_lim < s().init_trail_size(); ++m_trail_lim) {
auto lit = s().trail_literal(m_trail_lim);
auto e = ctx.literal2expr(lit);
if (is_unit(e)) {
// IF_VERBOSE(1, verbose_stream() << "add unit " << mk_pp(e, m) << "\n");
std::lock_guard<std::mutex> lock(m_mutex);
ast_translation tr(m, *m_shared);
m_units->push_back(tr(e.get()));
m_has_units = true;
}
std::lock_guard<std::mutex> lock(m_mutex);
m_units.push_back(lit);
m_has_units = true;
}
}
class solver::smt_plugin : public sat::local_search_plugin, public sls::sat_solver_context {
ast_manager& m;
sat::ddfw* m_ddfw;
solver& s;
sls::context m_context;
bool m_new_clause_added = false;
public:
smt_plugin(ast_manager& m, solver& s, sat::ddfw* d) :
m(m), s(s), m_ddfw(d), m_context(m, *this) {}
void init_search() override {}
void finish_search() override {}
void on_rescale() override {}
void on_restart() override {
if (!s.m_has_units)
return;
{
std::lock_guard<std::mutex> lock(s.m_mutex);
for (auto lit : s.m_units)
if (m_ddfw->is_initial_var(lit.var()))
m_ddfw->add(1, &lit);
s.m_has_units = false;
s.m_units.reset();
}
m_ddfw->reinit();
}
void on_save_model() override {
TRACE("sls", display(tout));
while (unsat().empty()) {
m_context.check();
if (!m_new_clause_added)
break;
m_ddfw->reinit();
m_new_clause_added = false;
}
}
void on_model(model_ref& mdl) override {
IF_VERBOSE(1, verbose_stream() << "on-model " << "\n");
s.m_sls_model = mdl;
}
void register_atom(sat::bool_var v, expr* e) {
m_context.register_atom(v, e);
}
std::ostream& display(std::ostream& out) {
m_ddfw->display(out);
m_context.display(out);
return out;
}
vector<sat::clause_info> const& clauses() const override { return m_ddfw->clauses(); }
sat::clause_info const& get_clause(unsigned idx) const override { return m_ddfw->get_clause_info(idx); }
std::initializer_list<unsigned> get_use_list(sat::literal lit) override { return m_ddfw->use_list(lit); }
void flip(sat::bool_var v) override { m_ddfw->flip(v); }
double reward(sat::bool_var v) override { return m_ddfw->get_reward(v); }
double get_weigth(unsigned clause_idx) override { return m_ddfw->get_clause_info(clause_idx).m_weight; }
bool is_true(sat::literal lit) override { return m_ddfw->get_value(lit.var()) != lit.sign(); }
unsigned num_vars() const override { return m_ddfw->num_vars(); }
indexed_uint_set const& unsat() const override { return m_ddfw->unsat_set(); }
sat::bool_var add_var() override { return m_ddfw->add_var(); }
void add_clause(unsigned n, sat::literal const* lits) override {
m_ddfw->add(n, lits);
m_new_clause_added = true;
}
};
void solver::init_search() {
if (m_sls) {
m_sls->cancel();
if (m_ddfw) {
m_ddfw->rlimit().cancel();
m_thread.join();
m_result = l_undef;
m_completed = false;
m_has_units = false;
m_model = nullptr;
m_units = nullptr;
}
// set up state for local search solver here
m_shared = alloc(ast_manager);
m_slsm = alloc(ast_manager);
m_units = alloc(expr_ref_vector, *m_shared);
ast_translation tr(m, *m_slsm);
m_completed = false;
m_result = l_undef;
m_completed = false;
m_slsm = alloc(ast_manager);
m_units.reset();
m_has_units = false;
m_model = nullptr;
m_sls = alloc(bv::sls, *m_slsm, s().params());
for (expr* a : ctx.get_assertions())
m_sls->assert_expr(tr(a));
m_sls_model = nullptr;
m_ddfw = alloc(sat::ddfw);
ast_translation tr(m, *m_slsm);
scoped_limits scoped_limits(m.limit());
scoped_limits.push_child(&m_slsm->limit());
scoped_limits.push_child(&m_ddfw->rlimit());
m_smt_plugin = alloc(smt_plugin, *m_slsm, *this, m_ddfw.get());
m_ddfw->set_plugin(m_smt_plugin);
m_ddfw->updt_params(s().params());
for (auto const& clause : ctx.top_level_clauses())
m_ddfw->add(clause.size(), clause.data());
for (sat::bool_var v = 0; v < s().num_vars(); ++v) {
expr* e = ctx.bool_var2expr(v);
if (e)
m_smt_plugin->register_atom(v, tr(e));
}
std::function<bool(expr*, unsigned)> eval = [&](expr* e, unsigned r) {
return false;
};
m_sls->init();
m_sls->init_eval(eval);
m_sls->updt_params(s().params());
m_sls->init_unit([&]() {
if (!m_has_units)
return expr_ref(*m_slsm);
expr_ref e(*m_slsm);
{
std::lock_guard<std::mutex> lock(m_mutex);
if (m_units->empty())
return expr_ref(*m_slsm);
ast_translation tr(*m_shared, *m_slsm);
e = tr(m_units->back());
m_units->pop_back();
}
return e;
});
m_sls->set_model([&](model& mdl) {
std::lock_guard<std::mutex> lock(m_mutex);
ast_translation tr(*m_shared, m);
m_model = mdl.translate(tr);
});
m_thread = std::thread([this]() { run_local_search(); });
run_local_search_sync();
// m_thread = std::thread([this]() { run_local_search_async(); });
}
void solver::sample_local_search() {
if (!m_completed)
return;
m_thread.join();
m_completed = false;
m_sls->collect_statistics(m_st);
if (m_result == l_true) {
IF_VERBOSE(2, verbose_stream() << "(sat.sls :model-completed)\n";);
auto mdl = m_sls->get_model();
ast_translation tr(*m_slsm, m);
m_model = mdl->translate(tr);
s().set_canceled();
}
m_sls = nullptr;
local_search_done();
}
void solver::run_local_search() {
m_result = (*m_sls)();
m_completed = true;
void solver::local_search_done() {
m_completed = false;
CTRACE("sls", m_smt_plugin, m_smt_plugin->display(tout));
if (m_ddfw)
m_ddfw->collect_statistics(m_st);
TRACE("sls", tout << "result " << m_result << "\n");
if (m_result == l_true && m_sls_model) {
ast_translation tr(*m_slsm, m);
m_model = m_sls_model->translate(tr);
TRACE("sls", tout << "model: " << *m_sls_model << "\n";);
s().set_canceled();
}
m_ddfw = nullptr;
m_smt_plugin = nullptr;
m_sls_model = nullptr;
}
void solver::run_local_search_async() {
if (m_ddfw) {
m_result = m_ddfw->check(0, nullptr, nullptr);
m_completed = true;
}
}
void solver::run_local_search_sync() {
m_result = m_ddfw->check(0, nullptr, nullptr);
local_search_done();
}
std::ostream& solver::display(std::ostream& out) const {
out << "sls-solver\n";
return out;
}
#endif

22
src/sat/smt/sls_solver.h
View file

@ -20,6 +20,7 @@ Author:
#include "util/rlimit.h"
#include "ast/sls/bv_sls.h"
#include "sat/smt/sat_th.h"
#include "sat/sat_ddfw.h"
#ifdef SINGLE_THREAD
@ -62,23 +63,28 @@ namespace euf {
namespace sls {
class solver : public euf::th_euf_solver {
class smt_plugin;
std::atomic<lbool> m_result;
std::atomic<bool> m_completed, m_has_units;
std::thread m_thread;
std::mutex m_mutex;
// m is accessed by the main thread
// m_slsm is accessed by the sls thread
// m_shared is only accessed at synchronization points
scoped_ptr<ast_manager> m_shared, m_slsm;
scoped_ptr<bv::sls> m_sls;
scoped_ptr<expr_ref_vector> m_units;
model_ref m_model;
scoped_ptr<ast_manager> m_slsm;
scoped_ptr<sat::ddfw> m_ddfw;
sat::literal_vector m_units;
smt_plugin* m_smt_plugin = nullptr;
model_ref m_model, m_sls_model;
unsigned m_trail_lim = 0;
statistics m_st;
void run_local_search();
void run_local_search_async();
void run_local_search_sync();
void sample_local_search();
bool is_unit(expr*);
void local_search_done();
public:
solver(euf::solver& ctx);
@ -98,7 +104,7 @@ namespace sls {
void internalize(expr* e) override { UNREACHABLE(); }
void get_antecedents(sat::literal l, sat::ext_justification_idx idx, sat::literal_vector & r, bool probing) override { UNREACHABLE(); }
sat::check_result check() override;
std::ostream & display(std::ostream & out) const override { return out; }
std::ostream& display(std::ostream& out) const override;
std::ostream & display_justification(std::ostream & out, sat::ext_justification_idx idx) const override { UNREACHABLE(); return out; }
std::ostream & display_constraint(std::ostream & out, sat::ext_constraint_idx idx) const override { UNREACHABLE(); return out; }

13
src/sat/tactic/goal2sat.cpp
View file

@ -139,10 +139,6 @@ struct goal2sat::imp : public sat::sat_internalizer {
return m_euf && ensure_euf()->relevancy_enabled();
}
bool top_level_relevant() {
return m_top_level && relevancy_enabled();
}
void mk_clause(sat::literal l1, sat::literal l2, euf::th_proof_hint* ph) {
sat::literal lits[2] = { l1, l2 };
mk_clause(2, lits, ph);
@ -158,6 +154,7 @@ struct goal2sat::imp : public sat::sat_internalizer {
if (relevancy_enabled())
ensure_euf()->add_aux(n, lits);
m_solver.add_clause(n, lits, mk_status(ph));
add_top_level_clause(n, lits);
}
void mk_root_clause(sat::literal l) {
@ -179,6 +176,7 @@ struct goal2sat::imp : public sat::sat_internalizer {
if (relevancy_enabled())
ensure_euf()->add_root(n, lits);
m_solver.add_clause(n, lits, ph ? mk_status(ph) : sat::status::input());
add_top_level_clause(n, lits);
}
sat::bool_var add_var(bool is_ext, expr* n) {
@ -895,7 +893,6 @@ struct goal2sat::imp : public sat::sat_internalizer {
process(n, true);
CTRACE("goal2sat", !m_result_stack.empty(), tout << m_result_stack << "\n";);
SASSERT(m_result_stack.empty());
add_assertion(n);
}
void insert_dep(expr* dep0, expr* dep, bool sign) {
@ -990,10 +987,12 @@ struct goal2sat::imp : public sat::sat_internalizer {
}
}
void add_assertion(expr* f) {
void add_top_level_clause(unsigned n, sat::literal const* lits) {
if (!m_top_level)
return;
auto* ext = dynamic_cast<euf::solver*>(m_solver.get_extension());
if (ext)
ext->add_assertion(f);
ext->add_clause(n, lits);
}
void update_model(model_ref& mdl) {