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use variable id as level, separate cut-set updates, add missing reset in pdd

This commit is contained in:
Nikolaj Bjorner 2020-01-08 02:15:45 -08:00
parent 55554215ac
commit 57846e50fa
8 changed files with 158 additions and 126 deletions

View file

@ -49,8 +49,9 @@ namespace dd {
m_nodes.reset();
m_free_nodes.reset();
m_pdd_stack.reset();
m_mpq_table.reset();
m_values.reset();
m_free_values.reset();
m_mpq_table.reset();
init_nodes(level2var);
}

View file

@ -83,12 +83,12 @@ namespace sat {
std::function<void (literal_vector const&)> on_xor =
[&,this](literal_vector const& xors) {
SASSERT(xors.size() > 1);
unsigned max_level = s.def_level(xors.back().var());
unsigned max_level = xors.back().var();
unsigned index = xors.size() - 1;
for (unsigned i = index; i-- > 0; ) {
literal l = xors[i];
if (s.def_level(l.var()) > max_level) {
max_level = s.def_level(l.var());
if (l.var() > max_level) {
max_level = l.var();
index = i;
}
}
@ -227,109 +227,138 @@ namespace sat {
vector<cut_set> aig_cuts::get_cuts(unsigned max_cut_size, unsigned max_cutset_size) {
unsigned_vector sorted = top_sort();
vector<cut_set> cuts;
cuts.resize(m_aig.size());
max_cut_size = std::min(cut().max_cut_size, max_cut_size);
cut_set cut_set2;
cut_set2.init(m_region, max_cutset_size + 1);
vector<cut_set> cuts(m_aig.size());
m_max_cut_size = std::min(cut().max_cut_size, max_cut_size);
m_max_cutset_size = max_cutset_size;
m_cut_set1.init(m_region, m_max_cutset_size + 1);
m_cut_set2.init(m_region, m_max_cutset_size + 1);
unsigned j = 0;
for (unsigned id : sorted) {
node const& n = m_aig[id];
if (!n.is_valid()) {
continue;
if (n.is_valid()) {
auto& cut_set = cuts[id];
cut_set.init(m_region, m_max_cutset_size + 1);
cut_set.push_back(cut(id));
sorted[j++] = id;
}
}
sorted.shrink(j);
augment(sorted, cuts);
return cuts;
}
void aig_cuts::augment(unsigned_vector const& ids, vector<cut_set>& cuts) {
for (unsigned id : ids) {
node const& n = m_aig[id];
SASSERT(n.is_valid());
auto& cut_set = cuts[id];
cut_set.init(m_region, max_cutset_size + 1);
if (n.is_var()) {
SASSERT(!n.sign());
}
else if (n.is_ite()) {
literal l1 = child(n, 0);
literal l2 = child(n, 1);
literal l3 = child(n, 2);
for (auto const& a : cuts[l1.var()]) {
for (auto const& b : cuts[l2.var()]) {
cut ab;
if (!ab.merge(a, b, max_cut_size)) {
continue;
}
for (auto const& c : cuts[l3.var()]) {
cut abc;
if (!abc.merge(ab, c, max_cut_size)) {
continue;
}
if (cut_set.size() >= max_cutset_size) break;
uint64_t t1 = a.shift_table(abc);
uint64_t t2 = b.shift_table(abc);
uint64_t t3 = c.shift_table(abc);
if (l1.sign()) t1 = ~t1;
if (l2.sign()) t2 = ~t2;
if (l3.sign()) t3 = ~t3;
abc.set_table((t1 & t2) | (~t1 & t3));
if (n.sign()) abc.negate();
// extract tree size: abc.m_tree_size = a.m_tree_size + b.m_tree_size + c.m_tree_size + 1;
cut_set.insert(abc);
}
}
}
augment_ite(n, cut_set, cuts);
}
else if (n.num_children() == 2) {
SASSERT(n.is_and() || n.is_xor());
literal l1 = child(n, 0);
literal l2 = child(n, 1);
for (auto const& a : cuts[l1.var()]) {
for (auto const& b : cuts[l2.var()]) {
if (cut_set.size() >= max_cutset_size) break;
cut c;
if (c.merge(a, b, max_cut_size)) {
uint64_t t1 = a.shift_table(c);
uint64_t t2 = b.shift_table(c);
if (l1.sign()) t1 = ~t1;
if (l2.sign()) t2 = ~t2;
uint64_t t3 = n.is_and() ? t1 & t2 : t1 ^ t2;
c.set_table(t3);
if (n.sign()) c.negate();
cut_set.insert(c);
}
}
if (cut_set.size() >= max_cutset_size) break;
}
augment_aig2(n, cut_set, cuts);
}
else if (n.num_children() < max_cut_size) {
SASSERT(n.is_and() || n.is_xor());
literal lit = child(n, 0);
for (auto const& a : cuts[lit.var()]) {
cut_set.push_back(a);
if (lit.sign()) {
cut_set.back().negate();
}
}
for (unsigned i = 1; i < n.num_children(); ++i) {
cut_set2.reset();
literal lit = child(n, i);
for (auto const& a : cut_set) {
for (auto const& b : cuts[lit.var()]) {
cut c;
if (cut_set2.size() >= max_cutset_size)
break;
if (c.merge(a, b, max_cut_size)) {
uint64_t t1 = a.shift_table(c);
uint64_t t2 = b.shift_table(c);
if (lit.sign()) t2 = ~t2;
uint64_t t3 = n.is_and() ? t1 & t2 : t1 ^ t2;
c.set_table(t3);
if (i + 1 == n.num_children() && n.sign()) c.negate();
cut_set2.insert(c);
}
}
if (cut_set2.size() >= max_cutset_size)
break;
}
cut_set.swap(cut_set2);
}
else if (n.num_children() < m_max_cut_size && cut_set.size() < m_max_cutset_size) {
augment_aigN(n, cut_set, cuts);
}
cut_set.push_back(cut(id));
}
return cuts;
}
void aig_cuts::augment_ite(node const& n, cut_set& cs, vector<cut_set>& cuts) {
literal l1 = child(n, 0);
literal l2 = child(n, 1);
literal l3 = child(n, 2);
for (auto const& a : cuts[l1.var()]) {
for (auto const& b : cuts[l2.var()]) {
cut ab;
if (!ab.merge(a, b, m_max_cut_size)) {
continue;
}
for (auto const& c : cuts[l3.var()]) {
cut abc;
if (!abc.merge(ab, c, m_max_cut_size)) {
continue;
}
if (cs.size() >= m_max_cutset_size) break;
uint64_t t1 = a.shift_table(abc);
uint64_t t2 = b.shift_table(abc);
uint64_t t3 = c.shift_table(abc);
if (l1.sign()) t1 = ~t1;
if (l2.sign()) t2 = ~t2;
if (l3.sign()) t3 = ~t3;
abc.set_table((t1 & t2) | (~t1 & t3));
if (n.sign()) abc.negate();
// extract tree size: abc.m_tree_size = a.m_tree_size + b.m_tree_size + c.m_tree_size + 1;
cs.insert(abc);
}
}
}
}
void aig_cuts::augment_aig2(node const& n, cut_set& cs, vector<cut_set>& cuts) {
SASSERT(n.is_and() || n.is_xor());
literal l1 = child(n, 0);
literal l2 = child(n, 1);
for (auto const& a : cuts[l1.var()]) {
for (auto const& b : cuts[l2.var()]) {
if (cs.size() >= m_max_cutset_size) break;
cut c;
if (c.merge(a, b, m_max_cut_size)) {
uint64_t t1 = a.shift_table(c);
uint64_t t2 = b.shift_table(c);
if (l1.sign()) t1 = ~t1;
if (l2.sign()) t2 = ~t2;
uint64_t t3 = n.is_and() ? t1 & t2 : t1 ^ t2;
c.set_table(t3);
if (n.sign()) c.negate();
cs.insert(c);
}
}
if (cs.size() >= m_max_cutset_size)
break;
}
}
void aig_cuts::augment_aigN(node const& n, cut_set& cs, vector<cut_set>& cuts) {
m_cut_set1.reset();
SASSERT(n.is_and() || n.is_xor());
literal lit = child(n, 0);
for (auto const& a : cuts[lit.var()]) {
m_cut_set1.push_back(a);
if (lit.sign()) {
m_cut_set1.back().negate();
}
}
for (unsigned i = 1; i < n.num_children(); ++i) {
m_cut_set2.reset();
literal lit = child(n, i);
for (auto const& a : m_cut_set1) {
for (auto const& b : cuts[lit.var()]) {
cut c;
if (m_cut_set2.size() + cs.size() >= m_max_cutset_size)
break;
if (c.merge(a, b, m_max_cut_size)) {
uint64_t t1 = a.shift_table(c);
uint64_t t2 = b.shift_table(c);
if (lit.sign()) t2 = ~t2;
uint64_t t3 = n.is_and() ? t1 & t2 : t1 ^ t2;
c.set_table(t3);
if (i + 1 == n.num_children() && n.sign()) c.negate();
m_cut_set2.insert(c);
}
}
if (m_cut_set2.size() + cs.size() >= m_max_cutset_size)
break;
}
m_cut_set1.swap(m_cut_set2);
}
for (auto & cut : m_cut_set1) {
cs.insert(cut);
}
}
void aig_cuts::add_var(unsigned v) {

View file

@ -32,7 +32,7 @@ namespace sat {
};
class aig_cuts {
// encodes one of var, n1 & n2 & .. & nk, !(n1 & n2 & .. & nk)
// encodes one of var, and, !and, xor, !xor, ite, !ite.
class node {
bool m_sign;
bool_op m_op;
@ -54,11 +54,20 @@ namespace sat {
unsigned num_children() const { SASSERT(!is_var()); return m_num_children; }
unsigned offset() const { return m_offset; }
};
svector<node> m_aig; // vector of aig nodes.
svector<node> m_aig; // vector of main aig nodes.
vector<svector<node>> m_aux_aig; // vector of auxiliary aig nodes.
literal_vector m_literals;
region m_region;
unsigned m_max_cut_size;
unsigned m_max_cutset_size;
cut_set m_cut_set1, m_cut_set2;
unsigned_vector top_sort();
void augment(unsigned_vector const& ids, vector<cut_set>& cuts);
void augment_ite(node const& n, cut_set& cs, vector<cut_set>& cuts);
void augment_aig2(node const& n, cut_set& cs, vector<cut_set>& cuts);
void augment_aigN(node const& n, cut_set& cs, vector<cut_set>& cuts);
public:
void add_var(unsigned v);
void add_node(literal head, bool_op op, unsigned sz, literal const* args);

View file

@ -353,7 +353,7 @@ namespace sat {
/**
assign levels to variables.
use s.def_level as a primary source for the level of a variable.
use variable id as a primary source for the level of a variable.
secondarily, sort variables randomly (each variable is assigned
a random, unique, id).
*/
@ -365,7 +365,7 @@ namespace sat {
for (unsigned i = 0; i < nv; ++i) var2id[i] = i;
shuffle(var2id.size(), var2id.c_ptr(), s.rand());
for (unsigned i = 0; i < nv; ++i) id2var[var2id[i]] = i;
for (unsigned i = 0; i < nv; ++i) vl[i] = std::make_pair(s.def_level(i), var2id[i]);
for (unsigned i = 0; i < nv; ++i) vl[i] = std::make_pair(i, var2id[i]);
std::sort(vl.begin(), vl.end());
for (unsigned i = 0; i < nv; ++i) l2v[i] = id2var[vl[i].second];

View file

@ -151,7 +151,6 @@ namespace sat {
m_phase[v] = src.m_phase[v];
m_best_phase[v] = src.m_best_phase[v];
m_prev_phase[v] = src.m_prev_phase[v];
m_level[v] = src.m_level[v];
// inherit activity:
m_activity[v] = src.m_activity[v];
@ -239,7 +238,7 @@ namespace sat {
//
// -----------------------
bool_var solver::mk_var(bool ext, bool dvar, unsigned level) {
bool_var solver::mk_var(bool ext, bool dvar) {
m_model_is_current = false;
m_stats.m_mk_var++;
bool_var v = m_justification.size();
@ -251,7 +250,6 @@ namespace sat {
m_decision.push_back(dvar);
m_eliminated.push_back(false);
m_external.push_back(ext);
m_level.push_back(level);
m_touched.push_back(0);
m_activity.push_back(0);
m_mark.push_back(false);
@ -3859,7 +3857,6 @@ namespace sat {
m_decision.shrink(v);
m_eliminated.shrink(v);
m_external.shrink(v);
m_level.shrink(v);
m_touched.shrink(v);
m_activity.shrink(v);
m_mark.shrink(v);

View file

@ -122,7 +122,6 @@ namespace sat {
svector<bool> m_lit_mark;
svector<bool> m_eliminated;
svector<bool> m_external;
unsigned_vector m_level;
unsigned_vector m_touched;
unsigned m_touch_index;
literal_vector m_replay_assign;
@ -248,9 +247,9 @@ namespace sat {
//
// -----------------------
void add_clause(unsigned num_lits, literal * lits, bool learned) override { mk_clause(num_lits, lits, learned); }
bool_var add_var(bool ext, unsigned level = 0) override { return mk_var(ext, true, level); }
bool_var add_var(bool ext) override { return mk_var(ext, true); }
bool_var mk_var(bool ext = false, bool dvar = true, unsigned level = 0);
bool_var mk_var(bool ext = false, bool dvar = true);
clause* mk_clause(literal_vector const& lits, bool learned = false) { return mk_clause(lits.size(), lits.c_ptr(), learned); }
clause* mk_clause(unsigned num_lits, literal * lits, bool learned = false);
@ -335,7 +334,6 @@ namespace sat {
bool was_eliminated(bool_var v) const { return m_eliminated[v]; }
void set_eliminated(bool_var v, bool f) override;
bool was_eliminated(literal l) const { return was_eliminated(l.var()); }
unsigned def_level(bool_var v) const { return m_level[v]; }
unsigned scope_lvl() const { return m_scope_lvl; }
unsigned search_lvl() const { return m_search_lvl; }
bool at_search_lvl() const { return m_scope_lvl == m_search_lvl; }

View file

@ -63,9 +63,7 @@ namespace sat {
add_clause(3, lits, is_redundant);
}
// create boolean variable, tagged as external (= true) or internal (can be eliminated).
// the level indicates the depth in an ast the variable comes from.
// variables of higher levels are outputs gates relative to lower levels
virtual bool_var add_var(bool ext, unsigned level = 0) = 0;
virtual bool_var add_var(bool ext) = 0;
// update parameters
virtual void updt_params(params_ref const& p) {}

View file

@ -121,7 +121,7 @@ struct goal2sat::imp {
sat::literal mk_true() {
if (m_true == sat::null_literal) {
// create fake variable to represent true;
m_true = sat::literal(m_solver.add_var(false, 0), false);
m_true = sat::literal(m_solver.add_var(false), false);
mk_clause(m_true); // v is true
}
return m_true;
@ -140,7 +140,7 @@ struct goal2sat::imp {
}
else {
bool ext = m_default_external || !is_uninterp_const(t) || m_interface_vars.contains(t);
sat::bool_var v = m_solver.add_var(ext, get_depth(t));
sat::bool_var v = m_solver.add_var(ext);
m_map.insert(t, v);
l = sat::literal(v, sign);
TRACE("sat", tout << "new_var: " << v << ": " << mk_bounded_pp(t, m, 2) << "\n";);
@ -248,7 +248,7 @@ struct goal2sat::imp {
}
else {
SASSERT(num <= m_result_stack.size());
sat::bool_var k = m_solver.add_var(false, get_depth(t));
sat::bool_var k = m_solver.add_var(false);
sat::literal l(k, false);
m_cache.insert(t, l);
sat::literal * lits = m_result_stack.end() - num;
@ -287,7 +287,7 @@ struct goal2sat::imp {
}
else {
SASSERT(num <= m_result_stack.size());
sat::bool_var k = m_solver.add_var(false, get_depth(t));
sat::bool_var k = m_solver.add_var(false);
sat::literal l(k, false);
m_cache.insert(t, l);
// l => /\ lits
@ -330,7 +330,7 @@ struct goal2sat::imp {
m_result_stack.reset();
}
else {
sat::bool_var k = m_solver.add_var(false, get_depth(n));
sat::bool_var k = m_solver.add_var(false);
sat::literal l(k, false);
m_cache.insert(n, l);
mk_clause(~l, ~c, t);
@ -367,7 +367,7 @@ struct goal2sat::imp {
m_result_stack.reset();
}
else {
sat::bool_var k = m_solver.add_var(false, get_depth(t));
sat::bool_var k = m_solver.add_var(false);
sat::literal l(k, false);
m_cache.insert(t, l);
mk_clause(~l, l1, ~l2);
@ -391,7 +391,7 @@ struct goal2sat::imp {
return;
}
sat::literal_vector lits;
sat::bool_var v = m_solver.add_var(true, get_depth(t));
sat::bool_var v = m_solver.add_var(true);
lits.push_back(sat::literal(v, true));
convert_pb_args(num, lits);
// ensure that = is converted to xor
@ -473,7 +473,7 @@ struct goal2sat::imp {
m_ext->add_pb_ge(sat::null_bool_var, wlits, k1);
}
else {
sat::bool_var v = m_solver.add_var(true, get_depth(t));
sat::bool_var v = m_solver.add_var(true);
sat::literal lit(v, sign);
m_ext->add_pb_ge(v, wlits, k.get_unsigned());
TRACE("goal2sat", tout << "root: " << root << " lit: " << lit << "\n";);
@ -504,7 +504,7 @@ struct goal2sat::imp {
m_ext->add_pb_ge(sat::null_bool_var, wlits, k1);
}
else {
sat::bool_var v = m_solver.add_var(true, get_depth(t));
sat::bool_var v = m_solver.add_var(true);
sat::literal lit(v, sign);
m_ext->add_pb_ge(v, wlits, k.get_unsigned());
TRACE("goal2sat", tout << "root: " << root << " lit: " << lit << "\n";);
@ -518,8 +518,8 @@ struct goal2sat::imp {
svector<wliteral> wlits;
convert_pb_args(t, wlits);
bool base_assert = (root && !sign && m_solver.num_user_scopes() == 0);
sat::bool_var v1 = base_assert ? sat::null_bool_var : m_solver.add_var(true, get_depth(t));
sat::bool_var v2 = base_assert ? sat::null_bool_var : m_solver.add_var(true, get_depth(t));
sat::bool_var v1 = base_assert ? sat::null_bool_var : m_solver.add_var(true);
sat::bool_var v2 = base_assert ? sat::null_bool_var : m_solver.add_var(true);
m_ext->add_pb_ge(v1, wlits, k.get_unsigned());
k.neg();
for (wliteral& wl : wlits) {
@ -533,7 +533,7 @@ struct goal2sat::imp {
}
else {
sat::literal l1(v1, false), l2(v2, false);
sat::bool_var v = m_solver.add_var(false, get_depth(t));
sat::bool_var v = m_solver.add_var(false);
sat::literal l(v, false);
mk_clause(~l, l1);
mk_clause(~l, l2);
@ -558,7 +558,7 @@ struct goal2sat::imp {
m_ext->add_at_least(sat::null_bool_var, lits, k2);
}
else {
sat::bool_var v = m_solver.add_var(true, get_depth(t));
sat::bool_var v = m_solver.add_var(true);
sat::literal lit(v, false);
m_ext->add_at_least(v, lits, k.get_unsigned());
m_cache.insert(t, lit);
@ -585,7 +585,7 @@ struct goal2sat::imp {
m_ext->add_at_least(sat::null_bool_var, lits, k2);
}
else {
sat::bool_var v = m_solver.add_var(true, get_depth(t));
sat::bool_var v = m_solver.add_var(true);
sat::literal lit(v, false);
m_ext->add_at_least(v, lits, k2);
m_cache.insert(t, lit);
@ -598,8 +598,8 @@ struct goal2sat::imp {
SASSERT(k.is_unsigned());
sat::literal_vector lits;
convert_pb_args(t->get_num_args(), lits);
sat::bool_var v1 = (root && !sign) ? sat::null_bool_var : m_solver.add_var(true, get_depth(t));
sat::bool_var v2 = (root && !sign) ? sat::null_bool_var : m_solver.add_var(true, get_depth(t));
sat::bool_var v1 = (root && !sign) ? sat::null_bool_var : m_solver.add_var(true);
sat::bool_var v2 = (root && !sign) ? sat::null_bool_var : m_solver.add_var(true);
m_ext->add_at_least(v1, lits, k.get_unsigned());
for (sat::literal& l : lits) {
l.neg();
@ -612,7 +612,7 @@ struct goal2sat::imp {
}
else {
sat::literal l1(v1, false), l2(v2, false);
sat::bool_var v = m_solver.add_var(false, get_depth(t));
sat::bool_var v = m_solver.add_var(false);
sat::literal l(v, false);
mk_clause(~l, l1);
mk_clause(~l, l2);