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z3/src/smt/theory_sls.cpp

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7.9 KiB
C++

/*++
Copyright (c) 2020 Microsoft Corporation
Module Name:
theory_sls
Abstract:
Interface to Concurrent SLS solver
Author:
Nikolaj Bjorner (nbjorner) 2024-10-24
--*/
#include "smt/smt_context.h"
#include "ast/sls/sls_context.h"
#include "ast/for_each_expr.h"
#include "smt/theory_sls.h"
namespace smt {
theory_sls::theory_sls(smt::context& ctx) :
theory(ctx, ctx.get_manager().mk_family_id("sls"))
{}
#ifndef SINGLE_THREAD
theory_sls::~theory_sls() {
finalize();
}
params_ref theory_sls::get_params() {
return ctx.get_params();
}
void theory_sls::set_value(expr* t, expr* v) {
ctx.user_propagate_initialize_value(t, v);
}
void theory_sls::force_phase(sat::literal lit) {
ctx.force_phase(lit);
}
void theory_sls::set_has_new_best_phase(bool b) {
}
bool theory_sls::get_best_phase(sat::bool_var v) {
return ctx.get_assignment(v) == l_true;
}
expr* theory_sls::bool_var2expr(sat::bool_var v) {
return ctx.bool_var2expr(v);
}
void theory_sls::set_finished() {
ctx.set_internal_completed();
}
bool theory_sls::get_smt_value(expr* v, expr_ref& value) {
if (!ctx.e_internalized(v))
return false;
auto* n = ctx.get_enode(v);
return n && ctx.get_value(n, value);
}
void theory_sls::inc_activity(sat::bool_var v, double inc) {
ctx.inc_bvar_activity(v, inc);
}
unsigned theory_sls::get_num_bool_vars() const {
return ctx.get_num_bool_vars();
}
void theory_sls::init_search_eh() {
m_init_search = true;
}
void theory_sls::finalize() const {
if (!m_smt_plugin)
return;
m_smt_plugin->finalize(m_model, m_st);
m_model = nullptr;
m_smt_plugin = nullptr;
m_init_search = false;
}
void theory_sls::propagate() {
if (!m_init_search)
return;
if (!m_smt_plugin)
m_smt_plugin = alloc(sls::smt_plugin, * this);
if (!m_checking) {
expr_ref_vector fmls(m);
for (unsigned i = 0; i < ctx.get_num_asserted_formulas(); ++i)
fmls.push_back(ctx.get_asserted_formula(i));
m_checking = true;
vector<sat::literal_vector> clauses;
m_smt_plugin->check(fmls, clauses);
m_smt_plugin->get_shared_clauses(m_shared_clauses);
}
else if (m_parallel_mode && m_smt_plugin->completed()) {
m_smt_plugin->finalize(m_model, m_st);
m_smt_plugin = nullptr;
m_init_search = false;
}
else
propagate_local_search();
}
void theory_sls::pop_scope_eh(unsigned n) {
if (!m_smt_plugin)
return;
if (ctx.get_search_level() == ctx.get_scope_level() - n) {
auto& lits = ctx.assigned_literals();
for (; m_trail_lim < lits.size() && ctx.get_assign_level(lits[m_trail_lim]) == ctx.get_search_level(); ++m_trail_lim)
m_smt_plugin->add_unit(lits[m_trail_lim]);
}
check_for_unassigned_clause_after_resolve();
#if 0
if (ctx.has_new_best_phase())
m_smt_plugin->import_phase_from_smt();
#endif
}
//
// hybrid-smt uses a heuristic to determine when to restart local search.
// it is based on when the assignment to shared clauses has a change in literal assignment.
//
void theory_sls::check_for_unassigned_clause_after_resolve() {
if (m_has_unassigned_clause_after_resolve) {
m_after_resolve_decide_count = 0;
if (m_after_resolve_decide_gap >= 16)
m_after_resolve_decide_gap /= 4;
}
else if (!shared_clauses_are_true()) {
m_resolve_count++;
if (m_resolve_count > m_resolve_gap) {
m_resolve_gap++;
m_has_unassigned_clause_after_resolve = true;
m_resolve_count = 0;
m_after_resolve_decide_count = 0;
m_after_resolve_decide_gap = 4;
}
}
}
void theory_sls::update_propagation_scope() {
if (m_propagation_scope > ctx.get_scope_level() && m_propagation_scope == m_max_propagation_scope) {
m_smt_plugin->smt_values_to_sls();
}
m_propagation_scope = ctx.get_scope_level();
m_max_propagation_scope = std::max(m_max_propagation_scope, m_propagation_scope);
}
void theory_sls::propagate_local_search() {
if (!m_has_unassigned_clause_after_resolve)
return;
if (!m_smt_plugin)
return;
++m_after_resolve_decide_count;
if (100 + m_after_resolve_decide_gap > m_after_resolve_decide_count) {
//update_propagation_scope();
return;
}
m_after_resolve_decide_gap *= 2;
if (!shared_clauses_are_true()) {
update_propagation_scope();
return;
}
m_resolve_count = 0;
m_has_unassigned_clause_after_resolve = false;
run_guided_sls();
}
void theory_sls::run_guided_sls() {
m_smt_plugin->smt_values_to_sls();
if (m_parallel_mode)
return;
++m_stats.m_num_guided_sls;
m_smt_plugin->smt_phase_to_sls();
m_smt_plugin->smt_units_to_sls();
bounded_run(m_final_check_ls_steps);
dec_final_check_ls_steps();
if (m_smt_plugin) {
m_smt_plugin->sls_phase_to_smt();
m_smt_plugin->sls_values_to_smt();
if (m_stats.m_num_guided_sls % 20 == 0)
m_smt_plugin->sls_activity_to_smt();
}
}
void theory_sls::init() {
if (m_smt_plugin)
finalize();
smt_params p(ctx.get_fparams());
m_parallel_mode = p.m_sls_parallel;
m_smt_plugin = nullptr;
m_checking = false;
m_init_search = false;
}
void theory_sls::collect_statistics(::statistics& st) const {
finalize();
st.copy(m_st);
st.update("sls-num-guided-search", m_stats.m_num_guided_sls);
st.update("sls-num-restart-search", m_stats.m_num_restart_sls);
}
void theory_sls::restart_eh() {
if (m_parallel_mode || !m_smt_plugin)
return;
if (ctx.m_stats.m_num_restarts >= m_restart_gap + 5) {
m_restart_gap *= 2;
m_smt_plugin->smt_units_to_sls();
++m_stats.m_num_restart_sls;
bounded_run(m_restart_ls_steps);
inc_restart_ls_steps();
if (m_smt_plugin)
m_smt_plugin->sls_activity_to_smt();
}
}
void theory_sls::bounded_run(unsigned num_steps) {
m_smt_plugin->bounded_run(num_steps);
if (m_smt_plugin->result() == l_true) {
m_smt_plugin->finalize(m_model, m_st);
m_smt_plugin = nullptr;
m_init_search = false;
}
}
final_check_status theory_sls::final_check_eh() {
if (!m_smt_plugin)
return FC_DONE;
++m_after_resolve_decide_count;
if (m_after_resolve_decide_gap > m_after_resolve_decide_count)
return FC_DONE;
m_after_resolve_decide_gap *= 2;
run_guided_sls();
return FC_DONE;
}
bool theory_sls::shared_clauses_are_true() const {
#if 0
for (auto const& cl : m_shared_clauses) {
for (auto lit : cl)
verbose_stream() << lit << " : " << ctx.get_assignment(lit);
verbose_stream() << "\n";
}
#endif
for (auto const& cl : m_shared_clauses)
if (all_of(cl, [this](sat::literal lit) { return ctx.get_assignment(lit) != l_true; }))
return false;
return true;
}
void theory_sls::display(std::ostream& out) const {
out << "theory-sls\n";
}
#endif
}