z3-z3-4.13.0.src.solver.simplifier_solver.cpp Maven / Gradle / Ivy
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/*++
Copyright (c) 2023 Microsoft Corporation
Module Name:
simplifier_solver.cpp
Abstract:
Implements a solver with simplifying pre-processing.
Author:
Nikolaj Bjorner (nbjorner) 2023-01-30
Notes:
- add translation for preprocess state.
- If the pre-processors are stateful, they need to be properly translated.
--*/
#include "util/params.h"
#include "ast/ast_util.h"
#include "ast/rewriter/expr_safe_replace.h"
#include "ast/simplifiers/dependent_expr_state.h"
#include "ast/simplifiers/then_simplifier.h"
#include "ast/rewriter/th_rewriter.h"
#include "solver/solver.h"
#include "solver/simplifier_solver.h"
#include "solver/solver_preprocess.h"
class simplifier_solver : public solver {
struct dep_expr_state : public dependent_expr_state {
simplifier_solver& s;
model_reconstruction_trail m_reconstruction_trail;
bool m_updated = false;
dep_expr_state(simplifier_solver& s) :dependent_expr_state(s.m), s(s), m_reconstruction_trail(s.m, m_trail) {}
~dep_expr_state() override {}
unsigned qtail() const override { return s.m_fmls.size(); }
dependent_expr const& operator[](unsigned i) override { return s.m_fmls[i]; }
void update(unsigned i, dependent_expr const& j) override {
SASSERT(j.fml());
check_false(j.fml());
s.m_fmls[i] = j;
m_updated = true;
}
void add(dependent_expr const& j) override { m_updated = true; check_false(j.fml()); s.m_fmls.push_back(j); }
bool inconsistent() override { return s.m_inconsistent; }
bool updated() override { return m_updated; }
void reset_updated() override { m_updated = false; }
model_reconstruction_trail& model_trail() override { return m_reconstruction_trail; }
std::ostream& display(std::ostream& out) const override {
unsigned i = 0;
for (auto const& d : s.m_fmls) {
if (i > 0 && i == qhead())
out << "---- head ---\n";
out << d << "\n";
++i;
}
m_reconstruction_trail.display(out);
return out;
}
void check_false(expr* f) {
if (s.m.is_false(f))
s.set_inconsistent();
}
void replay(unsigned qhead, expr_ref_vector& assumptions) {
m_reconstruction_trail.replay(qhead, assumptions, *this);
th_rewriter rw(s.m);
expr_ref tmp(s.m);
for (unsigned i = 0; i < assumptions.size(); ++i) {
tmp = assumptions.get(i);
rw(tmp);
assumptions[i] = tmp;
}
}
void flatten_suffix() override {
expr_mark seen;
unsigned j = qhead();
expr_ref_vector pinned(s.m);
for (unsigned i = qhead(); i < qtail(); ++i) {
expr* f = s.m_fmls[i].fml(), *g = nullptr;
pinned.push_back(f);
if (seen.is_marked(f))
continue;
seen.mark(f, true);
if (s.m.is_true(f))
continue;
if (s.m.is_and(f)) {
auto* d = s.m_fmls[i].dep();
for (expr* arg : *to_app(f))
add(dependent_expr(s.m, arg, nullptr, d));
continue;
}
if (s.m.is_not(f, g) && s.m.is_or(g)) {
auto* d = s.m_fmls[i].dep();
for (expr* arg : *to_app(g))
add(dependent_expr(s.m, mk_not(s.m, arg), nullptr, d));
continue;
}
if (i != j)
s.m_fmls[j] = s.m_fmls[i];
++j;
}
s.m_fmls.shrink(j);
}
};
ast_manager& m;
solver_ref s;
vector m_fmls;
dep_expr_state m_preprocess_state;
then_simplifier m_preprocess;
expr_ref_vector m_assumptions;
model_converter_ref m_mc;
bool m_inconsistent = false;
expr_safe_replace m_core_replace;
void replace(expr_ref_vector& r) {
expr_ref tmp(m);
for (unsigned i = 0; i < r.size(); ++i) {
m_core_replace(r.get(i), tmp);
r[i] = tmp;
}
}
void flush(expr_ref_vector& assumptions) {
unsigned qhead = m_preprocess_state.qhead();
expr_ref_vector orig_assumptions(assumptions);
m_core_replace.reset();
if (qhead < m_fmls.size()) {
m_preprocess.reduce();
if (!m.inc())
return;
TRACE("solver", tout << "qhead " << qhead << "\n";
m_preprocess_state.display(tout));
m_preprocess_state.advance_qhead();
}
if (!assumptions.empty()) {
m_preprocess_state.replay(m_preprocess_state.qhead(), assumptions);
for (unsigned i = 0; i < assumptions.size(); ++i)
m_core_replace.insert(assumptions.get(i), orig_assumptions.get(i));
}
m_mc = m_preprocess_state.model_trail().get_model_converter();
m_cached_mc = nullptr;
for (; qhead < m_fmls.size(); ++qhead)
add_with_dependency(m_fmls[qhead]);
}
ptr_vector m_deps;
void add_with_dependency(dependent_expr const& de) {
if (!de.dep()) {
s->assert_expr(de.fml());
return;
}
m_deps.reset();
m.linearize(de.dep(), m_deps);
m_assumptions.reset();
for (expr* d : m_deps)
m_assumptions.push_back(d);
s->assert_expr(de.fml(), mk_and(m_assumptions));
}
bool inconsistent() const {
return m_inconsistent;
}
void set_inconsistent() {
if (!m_inconsistent) {
m_preprocess_state.m_trail.push(value_trail(m_inconsistent));
m_inconsistent = true;
}
}
public:
simplifier_solver(solver* s, simplifier_factory* fac) :
solver(s->get_manager()),
m(s->get_manager()),
s(s),
m_preprocess_state(*this),
m_preprocess(m, s->get_params(), m_preprocess_state),
m_assumptions(m),
m_core_replace(m),
m_proof(m)
{
if (fac)
m_preprocess.add_simplifier((*fac)(m, s->get_params(), m_preprocess_state));
else
init_preprocess(m, s->get_params(), m_preprocess, m_preprocess_state);
}
void assert_expr_core2(expr* t, expr* a) override {
m_cached_model = nullptr;
m_cached_mc = nullptr;
proof* pr = m.proofs_enabled() ? m.mk_asserted(t) : nullptr;
m_fmls.push_back(dependent_expr(m, t, pr, m.mk_leaf(a)));
}
void assert_expr_core(expr* t) override {
m_cached_model = nullptr;
m_cached_mc = nullptr;
proof* pr = m.proofs_enabled() ? m.mk_asserted(t) : nullptr;
m_fmls.push_back(dependent_expr(m, t, pr, nullptr));
}
void push() override {
expr_ref_vector none(m);
flush(none);
m_preprocess_state.push();
m_preprocess.push();
m_preprocess_state.m_trail.push(restore_vector(m_fmls));
s->push();
}
void pop(unsigned n) override {
s->pop(n);
m_cached_model = nullptr;
m_preprocess.pop(n);
m_preprocess_state.pop(n);
}
lbool check_sat_core(unsigned num_assumptions, expr* const* assumptions) override {
expr_ref_vector _assumptions(m, num_assumptions, assumptions);
flush(_assumptions);
TRACE("simplifier", tout << _assumptions);
return s->check_sat_core(num_assumptions, _assumptions.data());
}
void collect_statistics(statistics& st) const override {
s->collect_statistics(st);
m_preprocess.collect_statistics(st);
}
model_ref m_cached_model;
void get_model_core(model_ref& m) override {
CTRACE("simplifier", m_mc.get(), m_mc->display(tout));
if (m_cached_model) {
m = m_cached_model;
return;
}
s->get_model(m);
if (m_mc)
(*m_mc)(m);
m_cached_model = m;
}
proof_ref m_proof;
proof* get_proof_core() override {
proof* p = s->get_proof();
m_proof = p;
if (p) {
expr_ref tmp(p, m);
expr_safe_replace sub(m);
for (auto const& d : m_fmls) {
if (d.pr())
sub.insert(m.mk_asserted(d.fml()), d.pr());
}
sub(tmp);
SASSERT(is_app(tmp));
m_proof = to_app(tmp);
}
return m_proof;
}
solver* translate(ast_manager& m, params_ref const& p) override {
solver* new_s = s->translate(m, p);
ast_translation tr(get_manager(), m);
simplifier_solver* result = alloc(simplifier_solver, new_s, nullptr); // factory?
for (dependent_expr const& f : m_fmls)
result->m_fmls.push_back(dependent_expr(tr, f));
if (m_mc)
result->m_mc = dynamic_cast(m_mc->translate(tr));
// copy m_preprocess_state?
return result;
}
void updt_params(params_ref const& p) override {
s->updt_params(p);
m_preprocess.updt_params(p);
}
mutable model_converter_ref m_cached_mc;
model_converter_ref get_model_converter() const override {
if (!m_cached_mc)
m_cached_mc = concat(solver::get_model_converter().get(), m_mc.get(), s->get_model_converter().get());
return m_cached_mc;
}
unsigned get_num_assertions() const override { return s->get_num_assertions(); }
expr* get_assertion(unsigned idx) const override { return s->get_assertion(idx); }
std::string reason_unknown() const override { return s->reason_unknown(); }
void set_reason_unknown(char const* msg) override { s->set_reason_unknown(msg); }
void get_labels(svector& r) override { s->get_labels(r); }
void get_unsat_core(expr_ref_vector& r) override { s->get_unsat_core(r); replace(r); }
ast_manager& get_manager() const override { return s->get_manager(); }
void reset_params(params_ref const& p) override { s->reset_params(p); }
params_ref const& get_params() const override { return s->get_params(); }
void collect_param_descrs(param_descrs& r) override { s->collect_param_descrs(r); }
void push_params() override { s->push_params(); }
void pop_params() override { s->pop_params(); }
void set_produce_models(bool f) override { s->set_produce_models(f); }
void set_phase(expr* e) override { s->set_phase(e); }
void move_to_front(expr* e) override { s->move_to_front(e); }
phase* get_phase() override { return s->get_phase(); }
void set_phase(phase* p) override { s->set_phase(p); }
unsigned get_num_assumptions() const override { return s->get_num_assumptions(); }
expr* get_assumption(unsigned idx) const override { return s->get_assumption(idx); }
unsigned get_scope_level() const override { return s->get_scope_level(); }
void set_progress_callback(progress_callback* callback) override { s->set_progress_callback(callback); }
lbool get_consequences(expr_ref_vector const& asms, expr_ref_vector const& vars, expr_ref_vector& consequences) override {
expr_ref_vector es(m);
es.append(asms);
es.append(vars);
flush(es);
expr_ref_vector asms1(m, asms.size(), es.data());
expr_ref_vector vars1(m, vars.size(), es.data() + asms.size());
lbool r = s->get_consequences(asms1, vars1, consequences);
replace(consequences);
return r;
}
lbool check_sat_cc(expr_ref_vector const& cube, vector const& clauses) override {
expr_ref_vector es(m);
es.append(cube);
for (auto const& c : clauses)
es.append(c);
flush(es);
expr_ref_vector cube1(m, cube.size(), es.data());
vector clauses1;
unsigned offset = cube.size();
for (auto const& c : clauses) {
clauses1.push_back(expr_ref_vector(m, c.size(), es.data() + offset));
offset += c.size();
}
return s->check_sat_cc(cube1, clauses1);
}
lbool find_mutexes(expr_ref_vector const& vars, vector& mutexes) override {
expr_ref_vector vars1(vars);
flush(vars1);
lbool r = s->find_mutexes(vars1, mutexes);
for (auto& mux : mutexes)
replace(mux);
return r;
}
lbool preferred_sat(expr_ref_vector const& asms, vector& cores) override {
expr_ref_vector asms1(asms);
flush(asms1);
lbool r = s->preferred_sat(asms1, cores);
for (auto& c : cores)
replace(c);
return r;
}
// todo flush?
expr_ref_vector cube(expr_ref_vector& vars, unsigned backtrack_level) override {
return s->cube(vars, backtrack_level);
}
expr* congruence_root(expr* e) override { return s->congruence_root(e); }
expr* congruence_next(expr* e) override { return s->congruence_next(e); }
std::ostream& display(std::ostream& out, unsigned n, expr* const* assumptions) const override {
return s->display(out, n, assumptions);
}
void get_units_core(expr_ref_vector& units) override { s->get_units_core(units); }
expr_ref_vector get_trail(unsigned max_level) override { return s->get_trail(max_level); }
void get_levels(ptr_vector const& vars, unsigned_vector& depth) override { s->get_levels(vars, depth); }
void register_on_clause(void* ctx, user_propagator::on_clause_eh_t& on_clause) override {
s->register_on_clause(ctx, on_clause);
}
void user_propagate_init(
void* ctx,
user_propagator::push_eh_t& push_eh,
user_propagator::pop_eh_t& pop_eh,
user_propagator::fresh_eh_t& fresh_eh) override {
s->user_propagate_init(ctx, push_eh, pop_eh, fresh_eh);
}
void user_propagate_register_fixed(user_propagator::fixed_eh_t& fixed_eh) override { s->user_propagate_register_fixed(fixed_eh); }
void user_propagate_register_final(user_propagator::final_eh_t& final_eh) override { s->user_propagate_register_final(final_eh); }
void user_propagate_register_eq(user_propagator::eq_eh_t& eq_eh) override { s->user_propagate_register_eq(eq_eh); }
void user_propagate_register_diseq(user_propagator::eq_eh_t& diseq_eh) override { s->user_propagate_register_diseq(diseq_eh); }
void user_propagate_register_expr(expr* e) override { m_preprocess_state.freeze(e); s->user_propagate_register_expr(e); }
void user_propagate_register_created(user_propagator::created_eh_t& r) override { s->user_propagate_register_created(r); }
void user_propagate_register_decide(user_propagator::decide_eh_t& r) override { s->user_propagate_register_decide(r); }
};
solver* mk_simplifier_solver(solver* s, simplifier_factory* fac) {
return alloc(simplifier_solver, s, fac);
}