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adding clause sharing to par mode

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2017-02-05 22:24:20 -08:00
parent 15283e4e7c
commit 7aeaf11ee4
7 changed files with 249 additions and 91 deletions

View file

@ -181,35 +181,6 @@ namespace sat {
s().set_conflict(justification::mk_ext_justification(c.index()), ~lit);
SASSERT(s().inconsistent());
}
literal card_extension::last_false_literal(card& c) {
while (!m_active_var_set.empty()) m_active_var_set.erase();
reset_coeffs();
for (unsigned i = 0; i < c.size(); ++i) {
bool_var v = c[i].var();
m_active_var_set.insert(v);
m_active_vars.push_back(v);
m_coeffs.setx(v, c[i].sign() ? -1 : 1, 0);
}
literal_vector const& lits = s().m_trail;
for (unsigned i = lits.size(); i > 0; ) {
--i;
literal lit = lits[i];
bool_var v = lit.var();
if (m_active_var_set.contains(v) &&
(m_coeffs[v] > 0 == lits[i].sign())) {
//std::cout << "last literal: " << lit << "\n";
for (unsigned j = 0; j < c.size(); ++j) {
if (~lit == c[j] && j != c.k()-1) {
// std::cout << "POSITION " << j << " bound " << c.k() << "\n";
}
}
return ~lit;
}
}
UNREACHABLE();
return null_literal;
}
void card_extension::normalize_active_coeffs() {
while (!m_active_var_set.empty()) m_active_var_set.erase();
@ -252,11 +223,9 @@ namespace sat {
}
// reduce coefficient to be no larger than bound.
if (coeff1 > m_bound) {
//if (m_bound > 1) std::cout << m_bound << " " << coeff1 << "\n";
m_coeffs[v] = m_bound;
}
else if (coeff1 < 0 && -coeff1 > m_bound) {
//if (m_bound > 1) std::cout << m_bound << " " << coeff1 << "\n";
m_coeffs[v] = -m_bound;
}
}
@ -302,19 +271,19 @@ namespace sat {
DEBUG_CODE(active2pb(m_A););
do {
// TRACE("sat", display(tout, m_A););
if (offset == 0) {
goto process_next_resolvent;
}
// TBD: need proper check for overflow.
if (offset > (1 << 12)) {
// std::cout << "offset: " << offset << "\n";
goto bail_out;
}
++num_steps;
// TRACE("sat", display(tout, m_A););
TRACE("sat", tout << "process consequent: " << consequent << ":\n"; s().display_justification(tout, js) << "\n";);
SASSERT(offset > 0);
SASSERT(m_bound >= 0);
@ -366,7 +335,7 @@ namespace sat {
card& c = *m_constraints[index];
m_bound += offset * c.k();
if (!process_card(c, offset)) {
std::cout << "failed to process card\n";
TRACE("sat", tout << "failed to process card\n";);
goto bail_out;
}
break;
@ -378,11 +347,13 @@ namespace sat {
SASSERT(validate_lemma());
DEBUG_CODE(
active2pb(m_C);
SASSERT(validate_resolvent());
//SASSERT(validate_resolvent());
m_A = m_C;);
TRACE("sat", display(tout << "conflict:\n", m_A););
// cut();
process_next_resolvent:
@ -404,31 +375,32 @@ namespace sat {
--m_num_marks;
js = s().m_justification[v];
offset = get_abs_coeff(v);
if (offset > m_bound) {
m_coeffs[v] = (get_coeff(v) < 0) ? -m_bound : m_bound;
offset = m_bound;
// TBD: also adjust coefficient in m_A.
}
SASSERT(value(consequent) == l_true);
}
while (m_num_marks > 0);
std::cout << m_num_propagations_since_pop << " " << num_steps << " " << num_card << "\n";
// std::cout << consequent << "\n";
DEBUG_CODE(for (bool_var i = 0; i < static_cast<bool_var>(s().num_vars()); ++i) SASSERT(!s().is_marked(i)););
SASSERT(validate_lemma());
normalize_active_coeffs();
if (consequent == null_literal) {
return false;
}
int slack = -m_bound;
for (unsigned i = 0; i < m_active_vars.size(); ++i) {
bool_var v = m_active_vars[i];
slack += get_abs_coeff(v);
}
TRACE("sat", display(tout, m_A););
++idx;
consequent = null_literal;
// std::cout << c.size() << " >= " << c.k() << "\n";
// std::cout << m_active_vars.size() << ": " << slack + m_bound << " >= " << m_bound << "\n";
++idx;
while (0 <= slack) {
literal lit = lits[idx];
@ -450,6 +422,11 @@ namespace sat {
}
else {
m_lemma.push_back(~lit);
if (lvl(lit) == m_conflict_lvl) {
TRACE("sat", tout << "Bail out on no progress " << lit << "\n";);
IF_VERBOSE(1, verbose_stream() << "bail cardinality lemma\n";);
return false;
}
}
}
}
@ -460,7 +437,6 @@ namespace sat {
SASSERT(slack < 0);
if (consequent == null_literal) {
std::cout << "null literal: " << m_lemma.empty() << "\n";
if (!m_lemma.empty()) return false;
}
else {
@ -473,8 +449,7 @@ namespace sat {
svector<drat::premise> ps; // TBD fill in
s().m_drat.add(m_lemma, ps);
}
// std::cout << m_lemma << "\n";
s().m_lemma.reset();
s().m_lemma.append(m_lemma);
for (unsigned i = 1; i < m_lemma.size(); ++i) {
@ -575,7 +550,6 @@ namespace sat {
}
SASSERT(found););
// std::cout << "antecedents: " << idx << ": " << l << " " << c.size() - c.k() + 1 << "\n";
r.push_back(c.lit());
SASSERT(value(c.lit()) == l_true);
for (unsigned i = c.k(); i < c.size(); ++i) {
@ -788,17 +762,12 @@ namespace sat {
}
std::ostream& card_extension::display_justification(std::ostream& out, ext_justification_idx idx) const {
if (idx == 0) {
out << "conflict: " << m_lemma;
}
else {
card& c = *m_constraints[idx];
out << "bound " << c.lit() << ": ";
for (unsigned i = c.k(); i < c.size(); ++i) {
out << c[i] << " ";
}
out << ">= " << c.k();
card& c = *m_constraints[idx];
out << "bound " << c.lit() << ": ";
for (unsigned i = 0; i < c.size(); ++i) {
out << c[i] << " ";
}
out << ">= " << c.k();
return out;
}
@ -932,22 +901,29 @@ namespace sat {
literal lit = m_C.m_lits[i];
unsigned coeff;
if (coeffs.find(lit.index(), coeff)) {
SASSERT(coeff <= m_C.m_coeffs[i] || m_C.m_coeffs[i] == m_C.m_k);
if (coeff > m_C.m_coeffs[i] && m_C.m_coeffs[i] < m_C.m_k) {
std::cout << i << ": " << m_C.m_coeffs[i] << " " << m_C.m_k << "\n";
goto violated;
}
coeffs.remove(lit.index());
}
}
if (!coeffs.empty() || m_C.m_k > k) {
display(std::cout, m_A);
display(std::cout, m_B);
display(std::cout, m_C);
u_map<unsigned>::iterator it = coeffs.begin(), end = coeffs.end();
for (; it != end; ++it) {
std::cout << to_literal(it->m_key) << ": " << it->m_value << "\n";
}
}
if (!coeffs.empty()) goto violated;
if (m_C.m_k > k) goto violated;
SASSERT(coeffs.empty());
SASSERT(m_C.m_k <= k);
return true;
violated:
display(std::cout, m_A);
display(std::cout, m_B);
display(std::cout, m_C);
u_map<unsigned>::iterator it = coeffs.begin(), end = coeffs.end();
for (; it != end; ++it) {
std::cout << to_literal(it->m_key) << ": " << it->m_value << "\n";
}
return false;
}
bool card_extension::validate_conflict(literal_vector const& lits, ineq& p) {

View file

@ -105,7 +105,6 @@ namespace sat {
lbool add_assign(card& c, literal lit);
void watch_literal(card& c, literal lit);
void set_conflict(card& c, literal lit);
literal last_false_literal(card& c);
void clear_watch(card& c);
void reset_coeffs();

View file

@ -198,13 +198,13 @@ namespace sat {
size_t size = clause::get_obj_size(num_lits);
void * mem = m_allocator.allocate(size);
clause * cls = new (mem) clause(m_id_gen.mk(), num_lits, lits, learned);
TRACE("sat", tout << "alloc: " << cls->id() << " " << *cls << " " << (learned?"l":"a") << "\n";);
TRACE("sat_clause", tout << "alloc: " << cls->id() << " " << *cls << " " << (learned?"l":"a") << "\n";);
SASSERT(!learned || cls->is_learned());
return cls;
}
void clause_allocator::del_clause(clause * cls) {
TRACE("sat", tout << "delete: " << cls->id() << " " << *cls << "\n";);
TRACE("sat_clause", tout << "delete: " << cls->id() << " " << *cls << "\n";);
m_id_gen.recycle(cls->id());
#if defined(_AMD64_)
#if defined(Z3DEBUG)

View file

@ -17,13 +17,84 @@ Revision History:
--*/
#include "sat_par.h"
#include "sat_clause.h"
#include "sat_solver.h"
namespace sat {
void par::vector_pool::next(unsigned& index) {
SASSERT(index < m_size);
unsigned n = index + 2 + get_length(index);
if (n >= m_size) {
index = 0;
}
else {
index = n;
}
}
void par::vector_pool::reserve(unsigned num_threads, unsigned sz) {
m_vectors.reset();
m_vectors.resize(sz, 0);
m_heads.reset();
m_heads.resize(num_threads, 0);
m_tail = 0;
m_size = sz;
}
void par::vector_pool::begin_add_vector(unsigned owner, unsigned n) {
unsigned capacity = n + 2;
m_vectors.reserve(m_size + capacity, 0);
IF_VERBOSE(3, verbose_stream() << owner << ": begin-add " << n << " tail: " << m_tail << " size: " << m_size << "\n";);
if (m_tail >= m_size) {
// move tail to the front.
for (unsigned i = 0; i < m_heads.size(); ++i) {
while (m_heads[i] < capacity) {
next(m_heads[i]);
}
IF_VERBOSE(3, verbose_stream() << owner << ": head: " << m_heads[i] << "\n";);
}
m_tail = 0;
}
else {
for (unsigned i = 0; i < m_heads.size(); ++i) {
while (m_tail < m_heads[i] && m_heads[i] < m_tail + capacity) {
next(m_heads[i]);
}
IF_VERBOSE(3, verbose_stream() << owner << ": head: " << m_heads[i] << "\n";);
}
}
m_vectors[m_tail++] = owner;
m_vectors[m_tail++] = n;
}
void par::vector_pool::add_vector_elem(unsigned e) {
m_vectors[m_tail++] = e;
}
bool par::vector_pool::get_vector(unsigned owner, unsigned& n, unsigned const*& ptr) {
unsigned head = m_heads[owner];
SASSERT(head < m_size);
while (head != m_tail) {
IF_VERBOSE(3, verbose_stream() << owner << ": head: " << head << " tail: " << m_tail << "\n";);
bool is_self = owner == get_owner(head);
next(m_heads[owner]);
if (!is_self) {
n = get_length(head);
ptr = get_ptr(head);
return true;
}
head = m_heads[owner];
}
return false;
}
par::par() {}
void par::exchange(literal_vector const& in, unsigned& limit, literal_vector& out) {
void par::exchange(solver& s, literal_vector const& in, unsigned& limit, literal_vector& out) {
if (s.m_par_syncing_clauses) return;
flet<bool> _disable_sync_clause(s.m_par_syncing_clauses, true);
#pragma omp critical (par_solver)
{
if (limit < m_units.size()) {
@ -40,6 +111,64 @@ namespace sat {
limit = m_units.size();
}
}
void par::share_clause(solver& s, literal l1, literal l2) {
if (s.m_par_syncing_clauses) return;
flet<bool> _disable_sync_clause(s.m_par_syncing_clauses, true);
#pragma omp critical (par_solver)
{
IF_VERBOSE(3, verbose_stream() << s.m_par_id << ": share " << l1 << " " << l2 << "\n";);
m_pool.begin_add_vector(s.m_par_id, 2);
m_pool.add_vector_elem(l1.index());
m_pool.add_vector_elem(l2.index());
}
}
void par::share_clause(solver& s, clause const& c) {
if (s.m_par_syncing_clauses) return;
flet<bool> _disable_sync_clause(s.m_par_syncing_clauses, true);
unsigned n = c.size();
unsigned owner = s.m_par_id;
#pragma omp critical (par_solver)
{
if (enable_add(c)) {
IF_VERBOSE(3, verbose_stream() << owner << ": share " << c << "\n";);
m_pool.begin_add_vector(owner, n);
for (unsigned i = 0; i < n; ++i) {
m_pool.add_vector_elem(c[i].index());
}
}
}
}
void par::get_clauses(solver& s) {
if (s.m_par_syncing_clauses) return;
flet<bool> _disable_sync_clause(s.m_par_syncing_clauses, true);
#pragma omp critical (par_solver)
{
_get_clauses(s);
}
}
void par::_get_clauses(solver& s) {
unsigned n;
unsigned const* ptr;
unsigned owner = s.m_par_id;
while (m_pool.get_vector(owner, n, ptr)) {
m_lits.reset();
for (unsigned i = 0; i < n; ++i) {
m_lits.push_back(to_literal(ptr[i]));
}
IF_VERBOSE(3, verbose_stream() << s.m_par_id << ": retrieve " << m_lits << "\n";);
SASSERT(n >= 2);
s.mk_clause_core(m_lits.size(), m_lits.c_ptr(), true);
}
}
bool par::enable_add(clause const& c) const {
// plingeling, glucose heuristic:
return (c.size() <= 40 && c.glue() <= 8) || c.glue() <= 2;
}
};

View file

@ -26,12 +26,50 @@ Revision History:
namespace sat {
class par {
// shared pool of learned clauses.
class vector_pool {
unsigned_vector m_vectors;
unsigned m_size;
unsigned m_tail;
unsigned_vector m_heads;
void next(unsigned& index);
unsigned get_owner(unsigned index) const { return m_vectors[index]; }
unsigned get_length(unsigned index) const { return m_vectors[index+1]; }
unsigned const* get_ptr(unsigned index) const { return m_vectors.c_ptr() + index + 2; }
public:
vector_pool() {}
void reserve(unsigned num_owners, unsigned sz);
void begin_add_vector(unsigned owner, unsigned n);
void add_vector_elem(unsigned e);
bool get_vector(unsigned owner, unsigned& n, unsigned const*& ptr);
};
bool enable_add(clause const& c) const;
void _get_clauses(solver& s);
typedef hashtable<unsigned, u_hash, u_eq> index_set;
literal_vector m_units;
index_set m_unit_set;
literal_vector m_lits;
vector_pool m_pool;
public:
par();
void exchange(literal_vector const& in, unsigned& limit, literal_vector& out);
// reserve space
void reserve(unsigned num_owners, unsigned sz) { m_pool.reserve(num_owners, sz); }
// exchange unit literals
void exchange(solver& s, literal_vector const& in, unsigned& limit, literal_vector& out);
// add clause to shared clause pool
void share_clause(solver& s, clause const& c);
void share_clause(solver& s, literal l1, literal l2);
// receive clauses from shared clause pool
void get_clauses(solver& s);
};
};

View file

@ -36,6 +36,8 @@ namespace sat {
m_config(p),
m_ext(ext),
m_par(0),
m_par_syncing_clauses(false),
m_par_id(0),
m_cleaner(*this),
m_simplifier(*this, p),
m_scc(*this, p),
@ -234,6 +236,7 @@ namespace sat {
return 0;
case 2:
mk_bin_clause(lits[0], lits[1], learned);
if (learned && m_par) m_par->share_clause(*this, lits[0], lits[1]);
return 0;
case 3:
return mk_ter_clause(lits, learned);
@ -836,6 +839,7 @@ namespace sat {
vector<reslimit> rlims(num_extra_solvers);
ptr_vector<sat::solver> solvers(num_extra_solvers);
sat::par par;
par.reserve(num_threads, 1 << 9);
symbol saved_phase = m_params.get_sym("phase", symbol("caching"));
for (int i = 0; i < num_extra_solvers; ++i) {
m_params.set_uint("random_seed", m_rand());
@ -844,10 +848,10 @@ namespace sat {
}
solvers[i] = alloc(sat::solver, m_params, rlims[i], 0);
solvers[i]->copy(*this);
solvers[i]->set_par(&par);
solvers[i]->set_par(&par, i);
scoped_rlimit.push_child(&solvers[i]->rlimit());
}
set_par(&par);
set_par(&par, num_extra_solvers);
m_params.set_sym("phase", saved_phase);
int finished_id = -1;
std::string ex_msg;
@ -901,7 +905,7 @@ namespace sat {
}
}
}
set_par(0);
set_par(0, 0);
if (finished_id != -1 && finished_id < num_extra_solvers) {
m_stats = solvers[finished_id]->m_stats;
}
@ -923,7 +927,9 @@ namespace sat {
\brief import lemmas/units from parallel sat solvers.
*/
void solver::exchange_par() {
if (m_par) {
if (m_par && at_base_lvl()) m_par->get_clauses(*this);
if (m_par && at_base_lvl()) {
// std::cout << scope_lvl() << " " << search_lvl() << "\n";
SASSERT(scope_lvl() == search_lvl());
// TBD: import also dependencies of assumptions.
unsigned sz = init_trail_size();
@ -937,7 +943,7 @@ namespace sat {
}
}
m_par_limit_out = sz;
m_par->exchange(out, m_par_limit_in, in);
m_par->exchange(*this, out, m_par_limit_in, in);
for (unsigned i = 0; !inconsistent() && i < in.size(); ++i) {
literal lit = in[i];
SASSERT(lit.var() < m_par_num_vars);
@ -952,11 +958,13 @@ namespace sat {
}
}
void solver::set_par(par* p) {
void solver::set_par(par* p, unsigned id) {
m_par = p;
m_par_num_vars = num_vars();
m_par_limit_in = 0;
m_par_limit_out = 0;
m_par_id = id;
m_par_syncing_clauses = false;
}
bool_var solver::next_var() {
@ -1855,10 +1863,11 @@ namespace sat {
unsigned glue = num_diff_levels(m_lemma.size(), m_lemma.c_ptr());
pop_reinit(m_scope_lvl - new_scope_lvl);
TRACE("sat_conflict_detail", display(tout); tout << "assignment:\n"; display_assignment(tout););
TRACE("sat_conflict_detail", tout << new_scope_lvl << "\n"; display(tout););
clause * lemma = mk_clause_core(m_lemma.size(), m_lemma.c_ptr(), true);
if (lemma) {
lemma->set_glue(glue);
if (m_par) m_par->share_clause(*this, *lemma);
}
decay_activity();
updt_phase_counters();
@ -1881,8 +1890,7 @@ namespace sat {
TRACE("sat", tout << "processing consequent: ";
if (consequent == null_literal) tout << "null\n";
else tout << consequent << "\n";
display_justification(tout << "js kind: ", js);
tout << "\n";);
display_justification(tout << "js kind: ", js) << "\n";);
switch (js.get_kind()) {
case justification::NONE:
break;
@ -1962,8 +1970,7 @@ namespace sat {
if (m_not_l != null_literal) {
justification js = m_justification[m_not_l.var()];
TRACE("sat", tout << "not_l: " << m_not_l << "\n";
display_justification(tout, js);
tout << "\n";);
display_justification(tout, js) << "\n";);
process_antecedent_for_unsat_core(m_not_l);
if (is_assumption(~m_not_l)) {
@ -2774,10 +2781,15 @@ namespace sat {
void solver::display_units(std::ostream & out) const {
unsigned end = m_trail.size(); // init_trail_size();
unsigned level = 0;
for (unsigned i = 0; i < end; i++) {
out << m_trail[i] << " ";
display_justification(out, m_justification[m_trail[i].var()]);
out << "\n";
literal lit = m_trail[i];
if (lvl(lit) > level) {
level = lvl(lit);
out << "level: " << level << " - ";
}
out << lit << " ";
display_justification(out, m_justification[lit.var()]) << "\n";
}
//if (end != 0)
// out << "\n";
@ -2794,7 +2806,7 @@ namespace sat {
out << ")\n";
}
void solver::display_justification(std::ostream & out, justification const& js) const {
std::ostream& solver::display_justification(std::ostream & out, justification const& js) const {
out << js;
if (js.is_clause()) {
out << *(m_cls_allocator.get_clause(js.get_clause_offset()));
@ -2802,6 +2814,7 @@ namespace sat {
else if (js.is_ext_justification() && m_ext) {
m_ext->display_justification(out << " ", js.get_ext_justification_idx());
}
return out;
}
unsigned solver::num_clauses() const {

View file

@ -134,9 +134,11 @@ namespace sat {
literal_set m_assumption_set; // set of enabled assumptions
literal_vector m_core; // unsat core
unsigned m_par_id;
unsigned m_par_limit_in;
unsigned m_par_limit_out;
unsigned m_par_num_vars;
bool m_par_syncing_clauses;
void del_clauses(clause * const * begin, clause * const * end);
@ -151,6 +153,7 @@ namespace sat {
friend class mus;
friend class drat;
friend class card_extension;
friend class par;
friend struct mk_stat;
public:
solver(params_ref const & p, reslimit& l, extension * ext);
@ -257,7 +260,7 @@ namespace sat {
m_num_checkpoints = 0;
if (memory::get_allocation_size() > m_config.m_max_memory) throw solver_exception(Z3_MAX_MEMORY_MSG);
}
void set_par(par* p);
void set_par(par* p, unsigned id);
bool canceled() { return !m_rlimit.inc(); }
config const& get_config() { return m_config; }
extension* get_extension() const { return m_ext.get(); }
@ -525,7 +528,7 @@ namespace sat {
void display_dimacs(std::ostream & out) const;
void display_wcnf(std::ostream & out, unsigned sz, literal const* lits, unsigned const* weights) const;
void display_assignment(std::ostream & out) const;
void display_justification(std::ostream & out, justification const& j) const;
std::ostream& display_justification(std::ostream & out, justification const& j) const;
protected:
void display_binary(std::ostream & out) const;