mirror of
https://github.com/Z3Prover/z3
synced 2025-04-13 20:38:43 +00:00
testing bdd for elim-vars
Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner
parent
6155362571
commit
dc6ed64da1
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@ -23,6 +23,8 @@ Revision History:
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namespace sat {
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bdd_manager::bdd_manager(unsigned num_vars) {
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m_cost_metric = bdd_cost;
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m_cost_bdd = 0;
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for (BDD a = 0; a < 2; ++a) {
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for (BDD b = 0; b < 2; ++b) {
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for (unsigned op = bdd_and_op; op < bdd_not_op; ++op) {
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@ -58,6 +60,7 @@ namespace sat {
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m_alloc.deallocate(sizeof(*m_spare_entry), m_spare_entry);
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}
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for (auto* e : m_op_cache) {
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VERIFY(e != m_spare_entry);
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m_alloc.deallocate(sizeof(*e), e);
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}
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}
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@ -78,16 +81,21 @@ namespace sat {
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bdd_manager::BDD bdd_manager::apply(BDD arg1, BDD arg2, bdd_op op) {
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bool first = true;
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SASSERT(well_formed());
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while (true) {
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try {
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return apply_rec(arg1, arg2, op);
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}
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catch (mem_out) {
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throw;
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#if 0
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try_reorder();
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if (!first) throw;
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first = false;
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#endif
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}
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}
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SASSERT(well_formed());
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}
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@ -101,17 +109,20 @@ namespace sat {
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bool bdd_manager::check_result(op_entry*& e1, op_entry const* e2, BDD a, BDD b, BDD c) {
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// std::cout << a << " " << b << " " << c << " " << e1 << " " << e2 << "\n";
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if (e1 != e2) {
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VERIFY(e2->m_result != -1);
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push_entry(e1);
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if (e2->m_bdd1 == a && e2->m_bdd2 == b && e2->m_op == c) {
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return true;
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}
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e1 = const_cast<op_entry*>(e2);
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e1 = nullptr;
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return true;
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}
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else {
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e1->m_bdd1 = a;
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e1->m_bdd2 = b;
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e1->m_op = c;
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VERIFY(e1->m_result == -1);
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return false;
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}
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e1->m_bdd1 = a;
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e1->m_bdd2 = b;
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e1->m_op = c;
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return false;
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}
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bdd_manager::BDD bdd_manager::apply_rec(BDD a, BDD b, bdd_op op) {
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@ -143,8 +154,10 @@ namespace sat {
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op_entry * e1 = pop_entry(a, b, op);
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op_entry const* e2 = m_op_cache.insert_if_not_there(e1);
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if (check_result(e1, e2, a, b, op)) {
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SASSERT(!m_free_nodes.contains(e2->m_result));
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return e2->m_result;
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}
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// VERIFY(well_formed());
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BDD r;
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if (level(a) == level(b)) {
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push(apply_rec(lo(a), lo(b), op));
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@ -163,6 +176,8 @@ namespace sat {
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}
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pop(2);
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e1->m_result = r;
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// VERIFY(well_formed());
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SASSERT(!m_free_nodes.contains(r));
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return r;
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}
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@ -190,6 +205,7 @@ namespace sat {
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else {
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void * mem = m_alloc.allocate(sizeof(op_entry));
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result = new (mem) op_entry(l, r, op);
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// std::cout << "alloc: " << result << "\n";
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}
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result->m_result = -1;
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return result;
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@ -200,16 +216,22 @@ namespace sat {
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m_spare_entry = e;
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}
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bdd_manager::BDD bdd_manager::make_node(unsigned level, BDD l, BDD r) {
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bdd_manager::BDD bdd_manager::make_node(unsigned lvl, BDD l, BDD h) {
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m_is_new_node = false;
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if (l == r) {
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if (l == h) {
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return l;
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}
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if (!is_const(l) && level(l) >= lvl) {
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display(std::cout << l << " level: " << level(l) << " lvl: " << lvl << "\n");
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}
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VERIFY(is_const(l) || level(l) < lvl);
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VERIFY(is_const(h) || level(h) < lvl);
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bdd_node n(level, l, r);
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bdd_node n(lvl, l, h);
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node_table::entry* e = m_node_table.insert_if_not_there2(n);
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if (e->get_data().m_index != 0) {
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return e->get_data().m_index;
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unsigned result = e->get_data().m_index;
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return result;
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}
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e->get_data().m_refcount = 0;
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bool do_gc = m_free_nodes.empty();
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@ -226,25 +248,50 @@ namespace sat {
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}
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SASSERT(!m_free_nodes.empty());
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e->get_data().m_index = m_free_nodes.back();
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m_nodes[e->get_data().m_index] = e->get_data();
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m_free_nodes.pop_back();
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m_is_new_node = true;
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return e->get_data().m_index;
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unsigned result = m_free_nodes.back();
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m_free_nodes.pop_back();
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e->get_data().m_index = result;
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m_nodes[result] = e->get_data();
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m_is_new_node = true;
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SASSERT(!m_free_nodes.contains(result));
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SASSERT(m_nodes[result].m_index == result);
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return result;
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}
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void bdd_manager::try_cnf_reorder(bdd const& b) {
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m_cost_bdd = b.root;
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m_cost_metric = cnf_cost;
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try_reorder();
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m_cost_metric = bdd_cost;
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m_cost_bdd = 0;
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}
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void bdd_manager::try_reorder() {
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gc();
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for (auto* e : m_op_cache) {
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m_alloc.deallocate(sizeof(*e), e);
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}
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m_op_cache.reset();
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init_reorder();
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for (unsigned i = 0; i < m_var2level.size(); ++i) {
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sift_var(i);
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}
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SASSERT(m_op_cache.empty());
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SASSERT(well_formed());
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}
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double bdd_manager::current_cost() {
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#if 0
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#endif
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return m_nodes.size() - m_free_nodes.size();
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switch (m_cost_metric) {
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case bdd_cost:
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return m_nodes.size() - m_free_nodes.size();
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case cnf_cost:
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return cnf_size(m_cost_bdd);
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case dnf_cost:
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return dnf_size(m_cost_bdd);
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default:
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UNREACHABLE();
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return 0;
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}
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}
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bool bdd_manager::is_bad_cost(double current_cost, double best_cost) const {
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@ -306,9 +353,11 @@ namespace sat {
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void bdd_manager::sift_up(unsigned lvl) {
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if (m_level2nodes[lvl].empty()) return;
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// VERIFY(well_formed());
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// exchange level and level + 1.
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m_S.reset();
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m_T.reset();
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m_to_free.reset();
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m_disable_gc = true;
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for (unsigned n : m_level2nodes[lvl + 1]) {
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@ -320,6 +369,8 @@ namespace sat {
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m_S.push_back(n);
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}
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else {
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reorder_decref(l);
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reorder_decref(h);
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m_T.push_back(n);
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}
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TRACE("bdd", tout << "remove " << n << "\n";);
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@ -331,14 +382,12 @@ namespace sat {
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for (unsigned n : m_level2nodes[lvl]) {
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bdd_node& node = m_nodes[n];
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m_node_table.remove(node);
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if (m_max_parent[n] == lvl + 1 && node.m_refcount == 0) {
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TRACE("bdd", tout << "free " << n << "\n";);
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node.set_internal();
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m_free_nodes.push_back(n);
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node.m_level = lvl + 1;
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if (m_reorder_rc[n] == 0) {
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m_to_free.push_back(n);
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}
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else {
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TRACE("bdd", tout << "set level " << n << " to " << lvl + 1 << "\n";);
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node.m_level = lvl + 1;
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m_node_table.insert(node);
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m_level2nodes[lvl + 1].push_back(n);
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}
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@ -352,19 +401,18 @@ namespace sat {
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}
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for (unsigned n : m_T) {
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TRACE("bdd", tout << "transform " << n << "\n";);
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BDD l = lo(n);
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BDD h = hi(n);
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if (l == 0 && h == 0) continue;
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BDD a, b, c, d;
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if (level(l) == lvl) {
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if (level(l) == lvl + 1) {
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a = lo(l);
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b = hi(l);
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}
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else {
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a = b = l;
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}
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if (level(h) == lvl) {
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if (level(h) == lvl + 1) {
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c = lo(h);
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d = hi(h);
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}
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@ -375,15 +423,22 @@ namespace sat {
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unsigned ac = make_node(lvl, a, c);
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if (is_new_node()) {
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m_level2nodes[lvl].push_back(ac);
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m_max_parent.setx(ac, lvl + 1, 0);
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m_reorder_rc.reserve(ac+1);
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reorder_incref(a);
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reorder_incref(c);
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}
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unsigned bd = make_node(lvl, b, d);
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if (is_new_node()) {
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m_level2nodes[lvl].push_back(bd);
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m_max_parent.setx(bd, lvl + 1, 0);
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m_reorder_rc.reserve(bd+1);
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reorder_incref(b);
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reorder_incref(d);
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}
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m_nodes[n].m_lo = ac;
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m_nodes[n].m_hi = bd;
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reorder_incref(ac);
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reorder_incref(bd);
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TRACE("bdd", tout << "transform " << n << " " << " " << a << " " << b << " " << c << " " << d << " " << ac << " " << bd << "\n";);
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m_node_table.insert(m_nodes[n]);
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}
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unsigned v = m_level2var[lvl];
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@ -391,6 +446,30 @@ namespace sat {
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std::swap(m_level2var[lvl], m_level2var[lvl+1]);
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std::swap(m_var2level[v], m_var2level[w]);
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m_disable_gc = false;
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// add orphaned nodes to free-list
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for (unsigned i = 0; i < m_to_free.size(); ++i) {
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unsigned n = m_to_free[i];
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bdd_node& node = m_nodes[n];
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if (!node.is_internal()) {
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VERIFY(!m_free_nodes.contains(n));
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VERIFY(node.m_refcount == 0);
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m_free_nodes.push_back(n);
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m_node_table.remove(node);
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BDD l = lo(n);
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BDD h = hi(n);
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node.set_internal();
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reorder_decref(l);
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if (!m_nodes[l].is_internal() && m_reorder_rc[l] == 0) {
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m_to_free.push_back(l);
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}
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reorder_decref(h);
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if (!m_nodes[h].is_internal() && m_reorder_rc[h] == 0) {
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m_to_free.push_back(h);
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}
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}
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}
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TRACE("bdd", tout << "sift " << lvl << "\n"; display(tout); );
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DEBUG_CODE(
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for (unsigned i = 0; i < m_level2nodes.size(); ++i) {
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@ -399,12 +478,24 @@ namespace sat {
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SASSERT(node.m_level == i);
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}
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});
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TRACE("bdd",
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for (unsigned i = 0; i < m_nodes.size(); ++i) {
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if (m_reorder_rc[i] != 0) {
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tout << i << " " << m_reorder_rc[i] << "\n";
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}});
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// VERIFY(well_formed());
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}
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void bdd_manager::init_reorder() {
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m_level2nodes.reset();
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unsigned sz = m_nodes.size();
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m_max_parent.fill(sz, 0);
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m_reorder_rc.fill(sz, 0);
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for (unsigned i = 0; i < sz; ++i) {
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if (m_nodes[i].m_refcount > 0)
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m_reorder_rc[i] = UINT_MAX;
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}
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for (unsigned i = 0; i < sz; ++i) {
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bdd_node const& n = m_nodes[i];
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if (n.is_internal()) continue;
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@ -412,8 +503,8 @@ namespace sat {
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SASSERT(i == m_nodes[i].m_index);
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m_level2nodes.reserve(lvl + 1);
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m_level2nodes[lvl].push_back(i);
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m_max_parent[n.m_lo] = std::max(m_max_parent[n.m_lo], lvl);
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m_max_parent[n.m_hi] = std::max(m_max_parent[n.m_hi], lvl);
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reorder_incref(n.m_lo);
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reorder_incref(n.m_hi);
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}
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TRACE("bdd",
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display(tout);
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@ -421,11 +512,19 @@ namespace sat {
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bdd_node const& n = m_nodes[i];
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if (n.is_internal()) continue;
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unsigned lvl = n.m_level;
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tout << "lvl: " << lvl << " parent: " << m_max_parent[i] << " lo " << n.m_lo << " hi " << n.m_hi << "\n";
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tout << i << " lvl: " << lvl << " rc: " << m_reorder_rc[i] << " lo " << n.m_lo << " hi " << n.m_hi << "\n";
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}
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);
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}
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void bdd_manager::reorder_incref(unsigned n) {
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if (m_reorder_rc[n] != UINT_MAX) m_reorder_rc[n]++;
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}
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void bdd_manager::reorder_decref(unsigned n) {
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if (m_reorder_rc[n] != UINT_MAX) m_reorder_rc[n]--;
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}
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void bdd_manager::reserve_var(unsigned i) {
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while (m_var2level.size() <= i) {
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unsigned v = m_var2level.size();
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@ -455,9 +554,12 @@ namespace sat {
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return bdd(mk_not_rec(b.root), this);
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}
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catch (mem_out) {
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throw;
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#if 0
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try_reorder();
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if (!first) throw;
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first = false;
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#endif
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}
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}
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}
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@ -532,12 +634,13 @@ namespace sat {
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push(mk_ite_rec(a1, b1, c1));
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push(mk_ite_rec(a2, b2, c2));
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r = make_node(lvl, read(2), read(1));
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pop(2);
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pop(2);
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e1->m_result = r;
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return r;
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}
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bdd bdd_manager::mk_exists(unsigned n, unsigned const* vars, bdd const& b) {
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// VERIFY(well_formed());
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return bdd(mk_quant(n, vars, b.root, bdd_or_op), this);
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}
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@ -570,9 +673,11 @@ namespace sat {
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bdd_op q_op = op == bdd_and_op ? bdd_and_proj_op : bdd_or_proj_op;
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op_entry * e1 = pop_entry(a, b, q_op);
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op_entry const* e2 = m_op_cache.insert_if_not_there(e1);
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if (check_result(e1, e2, a, b, q_op))
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if (check_result(e1, e2, a, b, q_op)) {
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r = e2->m_result;
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}
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else {
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VERIFY(e1->m_result == -1);
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push(mk_quant_rec(l, lo(b), op));
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push(mk_quant_rec(l, hi(b), op));
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r = make_node(lvl, read(2), read(1));
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@ -580,26 +685,29 @@ namespace sat {
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e1->m_result = r;
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}
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}
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VERIFY(r != UINT_MAX);
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return r;
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}
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double bdd_manager::count(bdd const& b, unsigned z) {
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double bdd_manager::count(BDD b, unsigned z) {
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init_mark();
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m_count.resize(m_nodes.size());
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m_count[0] = z;
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m_count[1] = 1-z;
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set_mark(0);
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set_mark(1);
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m_todo.push_back(b.root);
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m_todo.push_back(b);
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while (!m_todo.empty()) {
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BDD r = m_todo.back();
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if (is_marked(r)) {
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m_todo.pop_back();
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}
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else if (!is_marked(lo(r))) {
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VERIFY (is_const(r) || r != lo(r));
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m_todo.push_back(lo(r));
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}
|
||||
else if (!is_marked(hi(r))) {
|
||||
VERIFY (is_const(r) || r != hi(r));
|
||||
m_todo.push_back(hi(r));
|
||||
}
|
||||
else {
|
||||
|
|
@ -608,7 +716,7 @@ namespace sat {
|
|||
m_todo.pop_back();
|
||||
}
|
||||
}
|
||||
return m_count[b.root];
|
||||
return m_count[b];
|
||||
}
|
||||
|
||||
unsigned bdd_manager::bdd_size(bdd const& b) {
|
||||
|
|
@ -644,8 +752,8 @@ namespace sat {
|
|||
}
|
||||
|
||||
void bdd_manager::gc() {
|
||||
m_free_nodes.reset();
|
||||
IF_VERBOSE(3, verbose_stream() << "(bdd :gc " << m_nodes.size() << ")\n";);
|
||||
SASSERT(m_free_nodes.empty());
|
||||
svector<bool> reachable(m_nodes.size(), false);
|
||||
for (unsigned i = m_bdd_stack.size(); i-- > 0; ) {
|
||||
reachable[m_bdd_stack[i]] = true;
|
||||
|
|
@ -674,6 +782,7 @@ namespace sat {
|
|||
for (unsigned i = m_nodes.size(); i-- > 2; ) {
|
||||
if (!reachable[i]) {
|
||||
m_nodes[i].set_internal();
|
||||
VERIFY(m_nodes[i].m_refcount == 0);
|
||||
m_free_nodes.push_back(i);
|
||||
}
|
||||
}
|
||||
|
|
@ -681,10 +790,25 @@ namespace sat {
|
|||
std::sort(m_free_nodes.begin(), m_free_nodes.end());
|
||||
m_free_nodes.reverse();
|
||||
|
||||
for (auto* e : m_op_cache) {
|
||||
m_alloc.deallocate(sizeof(*e), e);
|
||||
ptr_vector<op_entry> to_delete, to_keep;
|
||||
for (auto* e : m_op_cache) {
|
||||
// std::cout << "check: " << e << "\n";
|
||||
if (!reachable[e->m_bdd1] || !reachable[e->m_bdd2] || !reachable[e->m_op] || (e->m_result != -1 && !reachable[e->m_result])) {
|
||||
to_delete.push_back(e);
|
||||
}
|
||||
else {
|
||||
to_keep.push_back(e);
|
||||
}
|
||||
}
|
||||
m_op_cache.reset();
|
||||
for (op_entry* e : to_delete) {
|
||||
// std::cout << "erase: " << e << "\n";
|
||||
m_alloc.deallocate(sizeof(*e), e);
|
||||
}
|
||||
for (op_entry* e : to_keep) {
|
||||
m_op_cache.insert(e);
|
||||
}
|
||||
|
||||
m_node_table.reset();
|
||||
// re-populate node cache
|
||||
for (unsigned i = m_nodes.size(); i-- > 2; ) {
|
||||
|
|
@ -693,6 +817,7 @@ namespace sat {
|
|||
m_node_table.insert(m_nodes[i]);
|
||||
}
|
||||
}
|
||||
SASSERT(well_formed());
|
||||
}
|
||||
|
||||
void bdd_manager::init_mark() {
|
||||
|
|
@ -707,6 +832,7 @@ namespace sat {
|
|||
std::ostream& bdd_manager::display(std::ostream& out, bdd const& b) {
|
||||
init_mark();
|
||||
m_todo.push_back(b.root);
|
||||
m_reorder_rc.reserve(m_nodes.size());
|
||||
while (!m_todo.empty()) {
|
||||
BDD r = m_todo.back();
|
||||
if (is_marked(r)) {
|
||||
|
|
@ -723,7 +849,7 @@ namespace sat {
|
|||
m_todo.push_back(hi(r));
|
||||
}
|
||||
else {
|
||||
out << r << " : " << var(r) << " " << lo(r) << " " << hi(r) << "\n";
|
||||
out << r << " : " << var(r) << " @ " << level(r) << " " << lo(r) << " " << hi(r) << " " << m_reorder_rc[r] << "\n";
|
||||
set_mark(r);
|
||||
m_todo.pop_back();
|
||||
}
|
||||
|
|
@ -731,30 +857,52 @@ namespace sat {
|
|||
return out;
|
||||
}
|
||||
|
||||
void bdd_manager::well_formed() {
|
||||
bool bdd_manager::well_formed() {
|
||||
for (unsigned n : m_free_nodes) {
|
||||
VERIFY(lo(n) == 0 && hi(n) == 0 && m_nodes[n].m_refcount == 0);
|
||||
if (!(lo(n) == 0 && hi(n) == 0 && m_nodes[n].m_refcount == 0)) {
|
||||
std::cout << "free node is not internal " << n << " " << lo(n) << " " << hi(n) << " " << m_nodes[n].m_refcount << "\n";
|
||||
display(std::cout);
|
||||
UNREACHABLE();
|
||||
}
|
||||
}
|
||||
for (bdd_node const& n : m_nodes) {
|
||||
if (n.is_internal()) continue;
|
||||
unsigned lvl = n.m_level;
|
||||
BDD lo = n.m_lo;
|
||||
BDD hi = n.m_hi;
|
||||
if (!is_const(lo) && level(lo) >= lvl) {
|
||||
std::cout << n.m_index << " lo: " << lo << "\n";
|
||||
display(std::cout);
|
||||
}
|
||||
VERIFY(is_const(lo) || level(lo) < lvl);
|
||||
if (!is_const(hi) && level(hi) >= lvl) {
|
||||
std::cout << n.m_index << " hi: " << hi << "\n";
|
||||
display(std::cout);
|
||||
}
|
||||
VERIFY(is_const(hi) || level(hi) < lvl);
|
||||
if (!is_const(lo) && m_nodes[lo].is_internal()) {
|
||||
std::cout << n.m_index << " lo: " << lo << "\n";
|
||||
display(std::cout);
|
||||
}
|
||||
if (!is_const(hi) && m_nodes[hi].is_internal()) {
|
||||
std::cout << n.m_index << " hi: " << hi << "\n";
|
||||
display(std::cout);
|
||||
}
|
||||
VERIFY(is_const(lo) || !m_nodes[lo].is_internal());
|
||||
VERIFY(is_const(hi) || !m_nodes[hi].is_internal());
|
||||
}
|
||||
return true;
|
||||
}
|
||||
|
||||
std::ostream& bdd_manager::display(std::ostream& out) {
|
||||
m_reorder_rc.reserve(m_nodes.size());
|
||||
for (unsigned i = 0; i < m_nodes.size(); ++i) {
|
||||
bdd_node const& n = m_nodes[i];
|
||||
if (n.is_internal()) continue;
|
||||
out << i << " : " << m_level2var[n.m_level] << " " << n.m_lo << " " << n.m_hi << "\n";
|
||||
out << i << " : v" << m_level2var[n.m_level] << " " << n.m_lo << " " << n.m_hi << " rc " << m_reorder_rc[i] << "\n";
|
||||
}
|
||||
for (unsigned i = 0; i < m_level2nodes.size(); ++i) {
|
||||
out << i << " : ";
|
||||
for (unsigned l : m_level2nodes[i]) out << l << " ";
|
||||
out << "\n";
|
||||
out << "level: " << i << " : " << m_level2nodes[i] << "\n";
|
||||
}
|
||||
return out;
|
||||
}
|
||||
|
|
|
|||
|
|
@ -50,7 +50,7 @@ namespace sat {
|
|||
m_hi(hi),
|
||||
m_index(0)
|
||||
{}
|
||||
bdd_node(): m_level(0), m_lo(0), m_hi(0), m_index(0) {}
|
||||
bdd_node(): m_refcount(0), m_level(0), m_lo(0), m_hi(0), m_index(0) {}
|
||||
unsigned m_refcount : 10;
|
||||
unsigned m_level : 22;
|
||||
BDD m_lo;
|
||||
|
|
@ -58,7 +58,13 @@ namespace sat {
|
|||
unsigned m_index;
|
||||
unsigned hash() const { return mk_mix(m_level, m_lo, m_hi); }
|
||||
bool is_internal() const { return m_lo == 0 && m_hi == 0; }
|
||||
void set_internal() { m_lo = m_hi = 0; }
|
||||
void set_internal() { m_lo = 0; m_hi = 0; }
|
||||
};
|
||||
|
||||
enum cost_metric {
|
||||
cnf_cost,
|
||||
dnf_cost,
|
||||
bdd_cost
|
||||
};
|
||||
|
||||
struct hash_node {
|
||||
|
|
@ -94,7 +100,7 @@ namespace sat {
|
|||
|
||||
struct eq_entry {
|
||||
bool operator()(op_entry * a, op_entry * b) const {
|
||||
return a->hash() == b->hash();
|
||||
return a->m_bdd1 == b->m_bdd2 && a->m_bdd2 == b->m_bdd2 && a->m_op == b->m_op;
|
||||
}
|
||||
};
|
||||
|
||||
|
|
@ -117,9 +123,11 @@ namespace sat {
|
|||
bool m_disable_gc;
|
||||
bool m_is_new_node;
|
||||
unsigned m_max_num_bdd_nodes;
|
||||
unsigned_vector m_S, m_T; // used for reordering
|
||||
unsigned_vector m_S, m_T, m_to_free; // used for reordering
|
||||
vector<unsigned_vector> m_level2nodes;
|
||||
unsigned_vector m_max_parent;
|
||||
unsigned_vector m_reorder_rc;
|
||||
cost_metric m_cost_metric;
|
||||
BDD m_cost_bdd;
|
||||
|
||||
BDD make_node(unsigned level, BDD l, BDD r);
|
||||
bool is_new_node() const { return m_is_new_node; }
|
||||
|
|
@ -141,15 +149,16 @@ namespace sat {
|
|||
void push_entry(op_entry* e);
|
||||
bool check_result(op_entry*& e1, op_entry const* e2, BDD a, BDD b, BDD c);
|
||||
|
||||
double count(bdd const& b, unsigned z);
|
||||
double count(BDD b, unsigned z);
|
||||
|
||||
void gc();
|
||||
void alloc_free_nodes(unsigned n);
|
||||
void init_mark();
|
||||
void set_mark(unsigned i) { m_mark[i] = m_mark_level; }
|
||||
bool is_marked(unsigned i) { return m_mark[i] == m_mark_level; }
|
||||
|
||||
void init_reorder();
|
||||
void reorder_incref(unsigned n);
|
||||
void reorder_decref(unsigned n);
|
||||
void sift_up(unsigned level);
|
||||
void sift_var(unsigned v);
|
||||
double current_cost();
|
||||
|
|
@ -166,12 +175,12 @@ namespace sat {
|
|||
inline unsigned var(BDD b) const { return m_level2var[level(b)]; }
|
||||
inline BDD lo(BDD b) const { return m_nodes[b].m_lo; }
|
||||
inline BDD hi(BDD b) const { return m_nodes[b].m_hi; }
|
||||
inline void inc_ref(BDD b) { if (m_nodes[b].m_refcount != max_rc) m_nodes[b].m_refcount++; }
|
||||
inline void dec_ref(BDD b) { if (m_nodes[b].m_refcount != max_rc) m_nodes[b].m_refcount--; }
|
||||
inline void inc_ref(BDD b) { if (m_nodes[b].m_refcount != max_rc) m_nodes[b].m_refcount++; VERIFY(!m_free_nodes.contains(b)); }
|
||||
inline void dec_ref(BDD b) { if (m_nodes[b].m_refcount != max_rc) m_nodes[b].m_refcount--; VERIFY(!m_free_nodes.contains(b)); }
|
||||
inline BDD level2bdd(unsigned l) const { return m_var2bdd[m_level2var[l]]; }
|
||||
|
||||
double dnf_size(bdd const& b) { return count(b, 0); }
|
||||
double cnf_size(bdd const& b) { return count(b, 1); }
|
||||
double dnf_size(BDD b) { return count(b, 0); }
|
||||
double cnf_size(BDD b) { return count(b, 1); }
|
||||
unsigned bdd_size(bdd const& b);
|
||||
|
||||
bdd mk_not(bdd b);
|
||||
|
|
@ -180,7 +189,7 @@ namespace sat {
|
|||
bdd mk_xor(bdd const& a, bdd const& b);
|
||||
|
||||
void reserve_var(unsigned v);
|
||||
void well_formed();
|
||||
bool well_formed();
|
||||
|
||||
public:
|
||||
struct mem_out {};
|
||||
|
|
@ -205,7 +214,9 @@ namespace sat {
|
|||
std::ostream& display(std::ostream& out);
|
||||
std::ostream& display(std::ostream& out, bdd const& b);
|
||||
|
||||
void gc();
|
||||
void try_reorder();
|
||||
void try_cnf_reorder(bdd const& b);
|
||||
};
|
||||
|
||||
class bdd {
|
||||
|
|
@ -234,8 +245,8 @@ namespace sat {
|
|||
std::ostream& display(std::ostream& out) const { return m->display(out, *this); }
|
||||
bool operator==(bdd const& other) const { return root == other.root; }
|
||||
bool operator!=(bdd const& other) const { return root != other.root; }
|
||||
double cnf_size() const { return m->cnf_size(*this); }
|
||||
double dnf_size() const { return m->dnf_size(*this); }
|
||||
double cnf_size() const { return m->cnf_size(root); }
|
||||
double dnf_size() const { return m->dnf_size(root); }
|
||||
unsigned bdd_size() const { return m->bdd_size(*this); }
|
||||
};
|
||||
|
||||
|
|
|
|||
|
|
@ -26,6 +26,7 @@ namespace sat{
|
|||
elim_vars::elim_vars(simplifier& s) : simp(s), s(s.s), m(20) {
|
||||
m_mark_lim = 0;
|
||||
m_max_literals = 11;
|
||||
m_miss = 0;
|
||||
}
|
||||
|
||||
bool elim_vars::operator()(bool_var v) {
|
||||
|
|
@ -57,10 +58,11 @@ namespace sat{
|
|||
double sz1 = b1.cnf_size();
|
||||
if (sz1 > 2*clause_size) {
|
||||
return false;
|
||||
}
|
||||
}
|
||||
if (sz1 <= clause_size) {
|
||||
return elim_var(v, b1);
|
||||
}
|
||||
|
||||
m_vars.reverse();
|
||||
bdd b2 = elim_var(v);
|
||||
double sz2 = b2.cnf_size();
|
||||
|
|
@ -73,6 +75,11 @@ namespace sat{
|
|||
if (sz3 <= clause_size) {
|
||||
return elim_var(v, b3);
|
||||
}
|
||||
#if 0
|
||||
m.try_cnf_reorder(b3);
|
||||
sz3 = b3.cnf_size();
|
||||
if (sz3 <= clause_size) ++m_miss;
|
||||
#endif
|
||||
return false;
|
||||
}
|
||||
|
||||
|
|
|
|||
|
|
@ -40,6 +40,7 @@ namespace sat {
|
|||
unsigned m_mark_lim;
|
||||
unsigned_vector m_var2index;
|
||||
unsigned_vector m_occ;
|
||||
unsigned m_miss;
|
||||
|
||||
unsigned m_max_literals;
|
||||
|
||||
|
|
@ -61,6 +62,7 @@ namespace sat {
|
|||
public:
|
||||
elim_vars(simplifier& s);
|
||||
bool operator()(bool_var v);
|
||||
unsigned miss() const { return m_miss; }
|
||||
};
|
||||
|
||||
};
|
||||
|
|
|
|||
|
|
@ -412,11 +412,17 @@ namespace sat {
|
|||
for (literal l1 : m_trail) {
|
||||
SASSERT(is_true(l1));
|
||||
for (literal l2 : m_binary[l1.index()]) {
|
||||
VERIFY(is_true(l2));
|
||||
if (is_undef(l2)) return true;
|
||||
}
|
||||
unsigned sz = m_ternary_count[(~l1).index()];
|
||||
for (binary b : m_ternary[(~l1).index()]) {
|
||||
if (sz-- == 0) break;
|
||||
if (!(is_true(b.m_u) || is_true(b.m_v) || (is_undef(b.m_v) && is_undef(b.m_u)))) {
|
||||
std::cout << b.m_u << " " << b.m_v << "\n";
|
||||
std::cout << get_level(b.m_u) << " " << get_level(b.m_v) << " level: " << m_level << "\n";
|
||||
UNREACHABLE();
|
||||
}
|
||||
if ((is_false(b.m_u) && is_undef(b.m_v)) || (is_false(b.m_v) && is_undef(b.m_u)))
|
||||
return true;
|
||||
}
|
||||
|
|
@ -424,6 +430,7 @@ namespace sat {
|
|||
for (nary * n : m_nary_clauses) {
|
||||
if (n->size() == 1 && !is_true(n->get_head())) {
|
||||
for (literal lit : *n) {
|
||||
VERIFY(!is_undef(lit));
|
||||
if (is_undef(lit)) return true;
|
||||
}
|
||||
}
|
||||
|
|
@ -1743,74 +1750,10 @@ namespace sat {
|
|||
|
||||
bool lookahead::check_autarky(literal l, unsigned level) {
|
||||
return false;
|
||||
#if 0
|
||||
// no propagations are allowed to reduce clauses.
|
||||
for (nary * cp : m_nary[(~l).index()]) {
|
||||
clause& c = *cp;
|
||||
unsigned sz = c.size();
|
||||
bool found = false;
|
||||
for (unsigned i = 0; !found && i < sz; ++i) {
|
||||
found = is_true(c[i]);
|
||||
if (found) {
|
||||
TRACE("sat", tout << c[i] << " is true in " << c << "\n";);
|
||||
}
|
||||
}
|
||||
IF_VERBOSE(2, verbose_stream() << "skip autarky " << l << "\n";);
|
||||
if (!found) return false;
|
||||
}
|
||||
//
|
||||
// bail out if there is a pending binary propagation.
|
||||
// In general, we would have to check, recursively that
|
||||
// a binary propagation does not create reduced clauses.
|
||||
//
|
||||
literal_vector const& lits = m_binary[l.index()];
|
||||
TRACE("sat", tout << l << ": " << lits << "\n";);
|
||||
for (unsigned i = 0; i < lits.size(); ++i) {
|
||||
literal l2 = lits[i];
|
||||
if (is_true(l2)) continue;
|
||||
SASSERT(!is_false(l2));
|
||||
return false;
|
||||
}
|
||||
|
||||
return true;
|
||||
#endif
|
||||
}
|
||||
|
||||
|
||||
void lookahead::update_lookahead_reward(literal l, unsigned level) {
|
||||
if (m_lookahead_reward == 0) {
|
||||
if (!check_autarky(l, level)) {
|
||||
// skip
|
||||
}
|
||||
else if (get_lookahead_reward(l) == 0) {
|
||||
++m_stats.m_autarky_propagations;
|
||||
IF_VERBOSE(1, verbose_stream() << "(sat.lookahead autarky " << l << ")\n";);
|
||||
|
||||
TRACE("sat", tout << "autarky: " << l << " @ " << m_stamp[l.var()]
|
||||
<< " "
|
||||
<< (!m_binary[l.index()].empty() || m_nary_count[l.index()] != 0) << "\n";);
|
||||
lookahead_backtrack();
|
||||
assign(l);
|
||||
propagate();
|
||||
}
|
||||
else {
|
||||
++m_stats.m_autarky_equivalences;
|
||||
// l => p is known, but p => l is possibly not.
|
||||
// add p => l.
|
||||
// justification: any consequence of l
|
||||
// that is not a consequence of p does not
|
||||
// reduce the clauses.
|
||||
literal p = get_parent(l);
|
||||
SASSERT(p != null_literal);
|
||||
if (m_stamp[p.var()] > m_stamp[l.var()]) {
|
||||
TRACE("sat", tout << "equivalence " << l << " == " << p << "\n"; display(tout););
|
||||
IF_VERBOSE(1, verbose_stream() << "(sat.lookahead equivalence " << l << " == " << p << ")\n";);
|
||||
add_binary(~l, p);
|
||||
set_level(l, p);
|
||||
}
|
||||
}
|
||||
}
|
||||
else {
|
||||
void lookahead::update_lookahead_reward(literal l, unsigned level) {
|
||||
if (m_lookahead_reward != 0) {
|
||||
inc_lookahead_reward(l, m_lookahead_reward);
|
||||
}
|
||||
}
|
||||
|
|
@ -1852,7 +1795,6 @@ namespace sat {
|
|||
literal last_changed = null_literal;
|
||||
unsigned num_iterations = 0;
|
||||
while (change && num_iterations < m_config.m_dl_max_iterations && !inconsistent()) {
|
||||
change = false;
|
||||
num_iterations++;
|
||||
for (unsigned i = 0; !inconsistent() && i < m_lookahead.size(); ++i) {
|
||||
literal lit = m_lookahead[i].m_lit;
|
||||
|
|
|
|||
|
|
@ -247,6 +247,7 @@ namespace sat {
|
|||
inline void set_true(literal l) { m_stamp[l.var()] = m_level + l.sign(); }
|
||||
inline void set_undef(literal l) { m_stamp[l.var()] = 0; }
|
||||
void set_level(literal d, literal s) { m_stamp[d.var()] = (m_stamp[s.var()] & ~0x1) + d.sign(); }
|
||||
unsigned get_level(literal d) const { return m_stamp[d.var()]; }
|
||||
lbool value(literal l) const { return is_undef(l) ? l_undef : is_true(l) ? l_true : l_false; }
|
||||
|
||||
// set the level within a scope of the search.
|
||||
|
|
|
|||
|
|
@ -1657,6 +1657,7 @@ namespace sat {
|
|||
bool_var_vector vars;
|
||||
order_vars_for_elim(vars);
|
||||
sat::elim_vars elim_bdd(*this);
|
||||
unsigned bdd_vars = 0;
|
||||
|
||||
for (bool_var v : vars) {
|
||||
checkpoint();
|
||||
|
|
@ -1665,10 +1666,13 @@ namespace sat {
|
|||
if (try_eliminate(v)) {
|
||||
m_num_elim_vars++;
|
||||
}
|
||||
else if (elim_bdd(v)) {
|
||||
else if (false && elim_bdd(v)) {
|
||||
m_num_elim_vars++;
|
||||
++bdd_vars;
|
||||
}
|
||||
}
|
||||
std::cout << "bdd elim: " << bdd_vars << "\n";
|
||||
std::cout << "bdd miss: " << elim_bdd.miss() << "\n";
|
||||
|
||||
m_pos_cls.finalize();
|
||||
m_neg_cls.finalize();
|
||||
|
|
|
|||
|
|
@ -67,6 +67,7 @@ namespace sat {
|
|||
std::cout << "before reorder:\n";
|
||||
std::cout << c1 << "\n";
|
||||
std::cout << c1.bdd_size() << "\n";
|
||||
m.gc();
|
||||
m.try_reorder();
|
||||
std::cout << "after reorder:\n";
|
||||
std::cout << c1 << "\n";
|
||||
|
|
|
|||
|
|
@ -472,6 +472,11 @@ typedef svector<char> char_vector;
|
|||
typedef svector<signed char> signed_char_vector;
|
||||
typedef svector<double> double_vector;
|
||||
|
||||
inline std::ostream& operator<<(std::ostream& out, unsigned_vector const& v) {
|
||||
for (unsigned u : v) out << u << " ";
|
||||
return out;
|
||||
}
|
||||
|
||||
template<typename Hash, typename Vec>
|
||||
struct vector_hash_tpl {
|
||||
Hash m_hash;
|
||||
|
|
|
|||
Loading…
Reference in a new issue