mirror of
https://github.com/Z3Prover/z3
synced 2025-04-15 13:28:47 +00:00
Merge branch 'opt' of https://github.com/nikolajbjorner/z3 into opt
This commit is contained in:
commit
6155362571
|
@ -18,6 +18,7 @@ Revision History:
|
|||
--*/
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#include "sat/sat_bdd.h"
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#include "util/trace.h"
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namespace sat {
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|
@ -48,12 +49,7 @@ namespace sat {
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// add variables
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for (unsigned i = 0; i < num_vars; ++i) {
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m_var2bdd.push_back(make_node(i, false_bdd, true_bdd));
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m_var2bdd.push_back(make_node(i, true_bdd, false_bdd));
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m_nodes[m_var2bdd[2*i]].m_refcount = max_rc;
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m_nodes[m_var2bdd[2*i+1]].m_refcount = max_rc;
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m_var2level.push_back(i);
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m_level2var.push_back(i);
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reserve_var(i);
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}
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}
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@ -73,8 +69,8 @@ namespace sat {
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return (a == true_bdd && b == true_bdd) ? true_bdd : false_bdd;
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case bdd_or_op:
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return (a == true_bdd || b == true_bdd) ? true_bdd : false_bdd;
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case bdd_iff_op:
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return (a == b) ? true_bdd : false_bdd;
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case bdd_xor_op:
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return (a == b) ? false_bdd : true_bdd;
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default:
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return false_bdd;
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}
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@ -99,7 +95,7 @@ namespace sat {
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bdd bdd_manager::mk_false() { return bdd(false_bdd, this); }
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bdd bdd_manager::mk_and(bdd const& a, bdd const& b) { return bdd(apply(a.root, b.root, bdd_and_op), this); }
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bdd bdd_manager::mk_or(bdd const& a, bdd const& b) { return bdd(apply(a.root, b.root, bdd_or_op), this); }
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bdd bdd_manager::mk_iff(bdd const& a, bdd const& b) { return bdd(apply(a.root, b.root, bdd_iff_op), this); }
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bdd bdd_manager::mk_xor(bdd const& a, bdd const& b) { return bdd(apply(a.root, b.root, bdd_xor_op), this); }
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bdd bdd_manager::mk_exists(unsigned v, bdd const& b) { return mk_exists(1, &v, b); }
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bdd bdd_manager::mk_forall(unsigned v, bdd const& b) { return mk_forall(1, &v, b); }
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@ -132,10 +128,10 @@ namespace sat {
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if (is_false(b)) return a;
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if (is_true(a) || is_true(b)) return true_bdd;
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break;
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case bdd_iff_op:
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if (a == b) return true_bdd;
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if (is_true(a)) return b;
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if (is_true(b)) return a;
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case bdd_xor_op:
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if (a == b) return false_bdd;
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if (is_false(a)) return b;
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if (is_false(b)) return a;
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break;
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default:
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UNREACHABLE();
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@ -265,9 +261,9 @@ namespace sat {
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goto go_down;
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}
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go_up:
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TRACE("bdd", tout << "sift up " << lvl << "\n";);
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while (lvl < max_lvl) {
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sift_up(lvl);
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++lvl;
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sift_up(lvl++);
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double cost = current_cost();
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if (is_bad_cost(cost, best_cost)) break;
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best_cost = std::min(cost, best_cost);
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@ -275,22 +271,20 @@ namespace sat {
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if (first) {
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first = false;
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while (lvl != start) {
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sift_up(lvl-1);
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--lvl;
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sift_up(--lvl);
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}
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goto go_down;
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}
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else {
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while (current_cost() != best_cost) {
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sift_up(lvl-1);
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--lvl;
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sift_up(--lvl);
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}
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return;
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}
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go_down:
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TRACE("bdd", tout << "sift down " << lvl << "\n";);
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while (lvl > 0) {
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sift_up(lvl-1);
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--lvl;
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sift_up(--lvl);
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double cost = current_cost();
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if (is_bad_cost(cost, best_cost)) break;
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best_cost = std::min(cost, best_cost);
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|
@ -298,15 +292,13 @@ namespace sat {
|
|||
if (first) {
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first = false;
|
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while (lvl != start) {
|
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sift_up(lvl);
|
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++lvl;
|
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sift_up(lvl++);
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}
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goto go_up;
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}
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else {
|
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while (current_cost() != best_cost) {
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sift_up(lvl);
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++lvl;
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sift_up(lvl++);
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}
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return;
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}
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|
@ -330,30 +322,37 @@ namespace sat {
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else {
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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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m_node_table.remove(m_nodes[n]);
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}
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m_level2nodes[lvl + 1].reset();
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m_level2nodes[lvl + 1].append(m_T);
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|
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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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}
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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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}
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m_level2nodes[lvl].reset();
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m_level2nodes[lvl].append(m_S);
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|
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for (unsigned n : m_S) {
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m_nodes[n].m_level = lvl;
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m_node_table.insert(m_nodes[n]);
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}
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std::swap(m_level2nodes[lvl], m_level2nodes[lvl + 1]);
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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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|
@ -392,6 +391,14 @@ 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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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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for (unsigned n : m_level2nodes[i]) {
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bdd_node const& node = m_nodes[n];
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SASSERT(node.m_level == i);
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}
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});
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}
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void bdd_manager::init_reorder() {
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|
@ -403,18 +410,41 @@ namespace sat {
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if (n.is_internal()) continue;
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unsigned lvl = n.m_level;
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SASSERT(i == m_nodes[i].m_index);
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while (m_level2nodes.size() <= lvl) m_level2nodes.push_back(unsigned_vector());
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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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}
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TRACE("bdd",
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display(tout);
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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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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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}
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);
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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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m_var2bdd.push_back(make_node(v, false_bdd, true_bdd));
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m_var2bdd.push_back(make_node(v, true_bdd, false_bdd));
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m_nodes[m_var2bdd[2*v]].m_refcount = max_rc;
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m_nodes[m_var2bdd[2*v+1]].m_refcount = max_rc;
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m_var2level.push_back(v);
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m_level2var.push_back(v);
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}
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}
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|
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bdd bdd_manager::mk_var(unsigned i) {
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reserve_var(i);
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return bdd(m_var2bdd[2*i], this);
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}
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bdd bdd_manager::mk_nvar(unsigned i) {
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reserve_var(i);
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return bdd(m_var2bdd[2*i+1], this);
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}
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|
@ -581,6 +611,29 @@ namespace sat {
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return m_count[b.root];
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}
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unsigned bdd_manager::bdd_size(bdd const& b) {
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init_mark();
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set_mark(0);
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set_mark(1);
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unsigned sz = 0;
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m_todo.push_back(b.root);
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while (!m_todo.empty()) {
|
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BDD r = m_todo.back();
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m_todo.pop_back();
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if (!is_marked(r)) {
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++sz;
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set_mark(r);
|
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if (!is_marked(lo(r))) {
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m_todo.push_back(lo(r));
|
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}
|
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if (!is_marked(hi(r))) {
|
||||
m_todo.push_back(hi(r));
|
||||
}
|
||||
}
|
||||
}
|
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return sz;
|
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}
|
||||
|
||||
void bdd_manager::alloc_free_nodes(unsigned n) {
|
||||
for (unsigned i = 0; i < n; ++i) {
|
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m_free_nodes.push_back(m_nodes.size());
|
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|
@ -678,31 +731,35 @@ namespace sat {
|
|||
return out;
|
||||
}
|
||||
|
||||
void bdd_manager::well_formed() {
|
||||
for (unsigned n : m_free_nodes) {
|
||||
VERIFY(lo(n) == 0 && hi(n) == 0 && m_nodes[n].m_refcount == 0);
|
||||
}
|
||||
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;
|
||||
VERIFY(is_const(lo) || level(lo) < lvl);
|
||||
VERIFY(is_const(hi) || level(hi) < lvl);
|
||||
}
|
||||
}
|
||||
|
||||
std::ostream& bdd_manager::display(std::ostream& out) {
|
||||
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";
|
||||
}
|
||||
for (unsigned i = 0; i < m_level2nodes.size(); ++i) {
|
||||
out << i << " : ";
|
||||
for (unsigned l : m_level2nodes[i]) out << l << " ";
|
||||
out << "\n";
|
||||
}
|
||||
return out;
|
||||
}
|
||||
|
||||
bdd::bdd(unsigned root, bdd_manager* m): root(root), m(m) { m->inc_ref(root); }
|
||||
bdd::bdd(bdd & other): root(other.root), m(other.m) { m->inc_ref(root); }
|
||||
bdd::bdd(bdd && other): root(0), m(other.m) { std::swap(root, other.root); }
|
||||
bdd::~bdd() { m->dec_ref(root); }
|
||||
bdd bdd::lo() const { return bdd(m->lo(root), m); }
|
||||
bdd bdd::hi() const { return bdd(m->hi(root), m); }
|
||||
unsigned bdd::var() const { return m->var(root); }
|
||||
bool bdd::is_true() const { return root == bdd_manager::true_bdd; }
|
||||
bool bdd::is_false() const { return root == bdd_manager::false_bdd; }
|
||||
bdd bdd::operator!() { return m->mk_not(*this); }
|
||||
bdd bdd::operator&&(bdd const& other) { return m->mk_and(*this, other); }
|
||||
bdd bdd::operator||(bdd const& other) { return m->mk_or(*this, other); }
|
||||
bdd& bdd::operator=(bdd const& other) { unsigned r1 = root; root = other.root; m->inc_ref(root); m->dec_ref(r1); return *this; }
|
||||
std::ostream& bdd::display(std::ostream& out) const { return m->display(out, *this); }
|
||||
std::ostream& operator<<(std::ostream& out, bdd const& b) { return b.display(out); }
|
||||
double bdd::cnf_size() const { return m->cnf_size(*this); }
|
||||
double bdd::dnf_size() const { return m->dnf_size(*this); }
|
||||
|
||||
}
|
||||
|
|
|
@ -35,7 +35,7 @@ namespace sat {
|
|||
enum bdd_op {
|
||||
bdd_and_op = 2,
|
||||
bdd_or_op = 3,
|
||||
bdd_iff_op = 4,
|
||||
bdd_xor_op = 4,
|
||||
bdd_not_op = 5,
|
||||
bdd_and_proj_op = 6,
|
||||
bdd_or_proj_op = 7,
|
||||
|
@ -149,7 +149,6 @@ namespace sat {
|
|||
void set_mark(unsigned i) { m_mark[i] = m_mark_level; }
|
||||
bool is_marked(unsigned i) { return m_mark[i] == m_mark_level; }
|
||||
|
||||
void try_reorder();
|
||||
void init_reorder();
|
||||
void sift_up(unsigned level);
|
||||
void sift_var(unsigned v);
|
||||
|
@ -173,10 +172,15 @@ namespace sat {
|
|||
|
||||
double dnf_size(bdd const& b) { return count(b, 0); }
|
||||
double cnf_size(bdd const& b) { return count(b, 1); }
|
||||
unsigned bdd_size(bdd const& b);
|
||||
|
||||
bdd mk_not(bdd b);
|
||||
bdd mk_and(bdd const& a, bdd const& b);
|
||||
bdd mk_or(bdd const& a, bdd const& b);
|
||||
bdd mk_xor(bdd const& a, bdd const& b);
|
||||
|
||||
void reserve_var(unsigned v);
|
||||
void well_formed();
|
||||
|
||||
public:
|
||||
struct mem_out {};
|
||||
|
@ -196,39 +200,43 @@ namespace sat {
|
|||
bdd mk_forall(unsigned n, unsigned const* vars, bdd const & b);
|
||||
bdd mk_exists(unsigned v, bdd const& b);
|
||||
bdd mk_forall(unsigned v, bdd const& b);
|
||||
bdd mk_iff(bdd const& a, bdd const& b);
|
||||
bdd mk_ite(bdd const& c, bdd const& t, bdd const& e);
|
||||
|
||||
std::ostream& display(std::ostream& out);
|
||||
std::ostream& display(std::ostream& out, bdd const& b);
|
||||
|
||||
void try_reorder();
|
||||
};
|
||||
|
||||
class bdd {
|
||||
friend class bdd_manager;
|
||||
unsigned root;
|
||||
bdd_manager* m;
|
||||
bdd(unsigned root, bdd_manager* m);
|
||||
bdd(unsigned root, bdd_manager* m): root(root), m(m) { m->inc_ref(root); }
|
||||
public:
|
||||
bdd(bdd & other);
|
||||
bdd(bdd && other);
|
||||
bdd(bdd & other): root(other.root), m(other.m) { m->inc_ref(root); }
|
||||
bdd(bdd && other): root(0), m(other.m) { std::swap(root, other.root); }
|
||||
bdd& operator=(bdd const& other);
|
||||
~bdd();
|
||||
bdd lo() const;
|
||||
bdd hi() const;
|
||||
unsigned var() const;
|
||||
bool is_true() const;
|
||||
bool is_false() const;
|
||||
|
||||
bdd operator!();
|
||||
bdd operator&&(bdd const& other);
|
||||
bdd operator||(bdd const& other);
|
||||
~bdd() { m->dec_ref(root); }
|
||||
bdd lo() const { return bdd(m->lo(root), m); }
|
||||
bdd hi() const { return bdd(m->hi(root), m); }
|
||||
unsigned var() const { return m->var(root); }
|
||||
|
||||
bool is_true() const { return root == bdd_manager::true_bdd; }
|
||||
bool is_false() const { return root == bdd_manager::false_bdd; }
|
||||
|
||||
bdd operator!() { return m->mk_not(*this); }
|
||||
bdd operator&&(bdd const& other) { return m->mk_and(*this, other); }
|
||||
bdd operator||(bdd const& other) { return m->mk_or(*this, other); }
|
||||
bdd operator^(bdd const& other) { return m->mk_xor(*this, other); }
|
||||
bdd operator|=(bdd const& other) { return *this = *this || other; }
|
||||
bdd operator&=(bdd const& other) { return *this = *this && other; }
|
||||
std::ostream& display(std::ostream& out) const;
|
||||
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;
|
||||
double dnf_size() const;
|
||||
double cnf_size() const { return m->cnf_size(*this); }
|
||||
double dnf_size() const { return m->dnf_size(*this); }
|
||||
unsigned bdd_size() const { return m->bdd_size(*this); }
|
||||
};
|
||||
|
||||
std::ostream& operator<<(std::ostream& out, bdd const& b);
|
||||
|
|
|
@ -38,16 +38,15 @@ namespace sat {
|
|||
return *this;
|
||||
}
|
||||
|
||||
void model_converter::process_stack(model & m, literal_vector const& stack) const {
|
||||
void model_converter::process_stack(model & m, literal_vector const& c, elim_stackv const& stack) const {
|
||||
SASSERT(!stack.empty());
|
||||
unsigned sz = stack.size();
|
||||
SASSERT(stack[sz - 1] == null_literal);
|
||||
for (unsigned i = sz - 1; i-- > 0; ) {
|
||||
literal lit = stack[i]; // this is the literal that is pivoted on. It is repeated
|
||||
for (unsigned i = sz; i-- > 0; ) {
|
||||
unsigned csz = stack[i].first;
|
||||
literal lit = stack[i].second;
|
||||
bool sat = false;
|
||||
for (; i > 0 && stack[--i] != null_literal;) {
|
||||
if (sat) continue;
|
||||
sat = value_at(stack[i], m) == l_true;
|
||||
for (unsigned j = 0; !sat && j < csz; ++j) {
|
||||
sat = value_at(c[j], m) == l_true;
|
||||
}
|
||||
if (!sat) {
|
||||
m[lit.var()] = lit.sign() ? l_false : l_true;
|
||||
|
@ -66,6 +65,7 @@ namespace sat {
|
|||
bool sat = false;
|
||||
bool var_sign = false;
|
||||
unsigned index = 0;
|
||||
literal_vector clause;
|
||||
for (literal l : it->m_clauses) {
|
||||
if (l == null_literal) {
|
||||
// end of clause
|
||||
|
@ -74,13 +74,15 @@ namespace sat {
|
|||
}
|
||||
elim_stack* s = it->m_elim_stack[index];
|
||||
if (s) {
|
||||
process_stack(m, s->stack());
|
||||
process_stack(m, clause, s->stack());
|
||||
}
|
||||
sat = false;
|
||||
++index;
|
||||
clause.reset();
|
||||
continue;
|
||||
}
|
||||
|
||||
clause.push_back(l);
|
||||
if (sat)
|
||||
continue;
|
||||
bool sign = l.sign();
|
||||
|
@ -190,13 +192,13 @@ namespace sat {
|
|||
// TRACE("sat_mc_bug", tout << "adding (wrapper): "; for (literal l : c) tout << l << " "; tout << "\n";);
|
||||
}
|
||||
|
||||
void model_converter::insert(entry & e, literal_vector const& c, literal_vector const& elims) {
|
||||
void model_converter::insert(entry & e, literal_vector const& c, elim_stackv const& elims) {
|
||||
SASSERT(c.contains(literal(e.var(), false)) || c.contains(literal(e.var(), true)));
|
||||
SASSERT(m_entries.begin() <= &e);
|
||||
SASSERT(&e < m_entries.end());
|
||||
for (literal l : c) e.m_clauses.push_back(l);
|
||||
e.m_clauses.push_back(null_literal);
|
||||
e.m_elim_stack.push_back(alloc(elim_stack, elims));
|
||||
e.m_elim_stack.push_back(elims.empty() ? nullptr : alloc(elim_stack, elims));
|
||||
TRACE("sat_mc_bug", tout << "adding: " << c << "\n";);
|
||||
}
|
||||
|
||||
|
|
|
@ -39,18 +39,20 @@ namespace sat {
|
|||
class model_converter {
|
||||
|
||||
public:
|
||||
typedef svector<std::pair<unsigned, literal>> elim_stackv;
|
||||
|
||||
class elim_stack {
|
||||
unsigned m_refcount;
|
||||
literal_vector m_stack;
|
||||
elim_stackv m_stack;
|
||||
public:
|
||||
elim_stack(literal_vector const& stack):
|
||||
elim_stack(elim_stackv const& stack):
|
||||
m_refcount(0),
|
||||
m_stack(stack) {
|
||||
}
|
||||
~elim_stack() { }
|
||||
void inc_ref() { ++m_refcount; }
|
||||
void dec_ref() { if (0 == --m_refcount) dealloc(this); }
|
||||
literal_vector const& stack() const { return m_stack; }
|
||||
elim_stackv const& stack() const { return m_stack; }
|
||||
};
|
||||
|
||||
enum kind { ELIM_VAR = 0, BLOCK_LIT };
|
||||
|
@ -74,7 +76,7 @@ namespace sat {
|
|||
private:
|
||||
vector<entry> m_entries;
|
||||
|
||||
void process_stack(model & m, literal_vector const& stack) const;
|
||||
void process_stack(model & m, literal_vector const& clause, elim_stackv const& stack) const;
|
||||
|
||||
public:
|
||||
model_converter();
|
||||
|
@ -86,7 +88,7 @@ namespace sat {
|
|||
void insert(entry & e, clause const & c);
|
||||
void insert(entry & e, literal l1, literal l2);
|
||||
void insert(entry & e, clause_wrapper const & c);
|
||||
void insert(entry & c, literal_vector const& covered_clause, literal_vector const& elim_stack);
|
||||
void insert(entry & c, literal_vector const& covered_clause, elim_stackv const& elim_stack);
|
||||
|
||||
bool empty() const { return m_entries.empty(); }
|
||||
|
||||
|
|
|
@ -965,6 +965,7 @@ namespace sat {
|
|||
literal l = m_queue.next();
|
||||
process(l);
|
||||
}
|
||||
cce();
|
||||
}
|
||||
|
||||
//
|
||||
|
@ -1027,55 +1028,106 @@ namespace sat {
|
|||
|
||||
literal_vector m_covered_clause;
|
||||
literal_vector m_intersection;
|
||||
literal_vector m_elim_stack;
|
||||
sat::model_converter::elim_stackv m_elim_stack;
|
||||
unsigned m_ala_qhead;
|
||||
|
||||
bool cla(literal lit) {
|
||||
/*
|
||||
* C \/ l l \/ lit
|
||||
* -------------------
|
||||
* C \/ l \/ ~lit
|
||||
*/
|
||||
void add_ala() {
|
||||
for (; m_ala_qhead < m_covered_clause.size(); ++m_ala_qhead) {
|
||||
literal l = m_covered_clause[m_ala_qhead];
|
||||
for (watched & w : s.get_wlist(~l)) {
|
||||
if (w.is_binary_clause()) {
|
||||
literal lit = w.get_literal();
|
||||
if (!s.is_marked(lit) && !s.is_marked(~lit)) {
|
||||
//std::cout << "ALA " << ~lit << "\n";
|
||||
m_covered_clause.push_back(~lit);
|
||||
s.mark_visited(~lit);
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
bool add_cla(literal& blocked) {
|
||||
for (unsigned i = 0; i < m_covered_clause.size(); ++i) {
|
||||
m_intersection.reset();
|
||||
if (ri(m_covered_clause[i], m_intersection)) {
|
||||
blocked = m_covered_clause[i];
|
||||
return true;
|
||||
}
|
||||
for (literal l : m_intersection) {
|
||||
if (!s.is_marked(l)) {
|
||||
s.mark_visited(l);
|
||||
m_covered_clause.push_back(l);
|
||||
}
|
||||
}
|
||||
if (!m_intersection.empty()) {
|
||||
m_elim_stack.push_back(std::make_pair(m_covered_clause.size(), m_covered_clause[i]));
|
||||
}
|
||||
}
|
||||
return false;
|
||||
}
|
||||
|
||||
bool cla(literal& blocked) {
|
||||
bool is_tautology = false;
|
||||
for (literal l : m_covered_clause) s.mark_visited(l);
|
||||
unsigned num_iterations = 0, sz;
|
||||
m_elim_stack.reset();
|
||||
m_ala_qhead = 0;
|
||||
do {
|
||||
++num_iterations;
|
||||
sz = m_covered_clause.size();
|
||||
for (unsigned i = 0; i < m_covered_clause.size(); ++i) {
|
||||
m_intersection.reset();
|
||||
if (ri(m_covered_clause[i], m_intersection) && m_covered_clause[i] == lit) {
|
||||
is_tautology = true;
|
||||
break;
|
||||
}
|
||||
for (literal l : m_intersection) {
|
||||
if (!s.is_marked(l)) {
|
||||
s.mark_visited(l);
|
||||
m_covered_clause.push_back(l);
|
||||
}
|
||||
}
|
||||
if (!m_intersection.empty()) {
|
||||
m_elim_stack.append(m_covered_clause); // the current clause
|
||||
m_elim_stack.push_back(m_covered_clause[i]); // the pivot literal
|
||||
m_elim_stack.push_back(null_literal); // null demarcation
|
||||
}
|
||||
do {
|
||||
++num_iterations;
|
||||
sz = m_covered_clause.size();
|
||||
is_tautology = add_cla(blocked);
|
||||
}
|
||||
while (m_covered_clause.size() > sz && !is_tautology);
|
||||
break;
|
||||
//if (is_tautology) break;
|
||||
//sz = m_covered_clause.size();
|
||||
// unsound? add_ala();
|
||||
}
|
||||
while (m_covered_clause.size() > sz && !is_tautology);
|
||||
while (m_covered_clause.size() > sz);
|
||||
for (literal l : m_covered_clause) s.unmark_visited(l);
|
||||
if (is_tautology) std::cout << "taut: " << num_iterations << "\n";
|
||||
// if (is_tautology) std::cout << "taut: " << num_iterations << " " << m_covered_clause.size() << " " << m_elim_stack.size() << "\n";
|
||||
return is_tautology;
|
||||
}
|
||||
|
||||
// perform covered clause elimination.
|
||||
// first extract the covered literal addition (CLA).
|
||||
// then check whether the CLA is blocked.
|
||||
bool cce(clause& c, literal lit) {
|
||||
bool cce(clause& c, literal& blocked) {
|
||||
m_covered_clause.reset();
|
||||
for (literal l : c) m_covered_clause.push_back(l);
|
||||
return cla(lit);
|
||||
return cla(blocked);
|
||||
}
|
||||
|
||||
bool cce(literal lit, literal l2) {
|
||||
bool cce(literal lit, literal l2, literal& blocked) {
|
||||
m_covered_clause.reset();
|
||||
m_covered_clause.push_back(lit);
|
||||
m_covered_clause.push_back(l2);
|
||||
return cla(lit);
|
||||
return cla(blocked);
|
||||
}
|
||||
|
||||
void cce() {
|
||||
m_to_remove.reset();
|
||||
literal blocked;
|
||||
for (clause* cp : s.s.m_clauses) {
|
||||
clause& c = *cp;
|
||||
if (c.was_removed()) continue;
|
||||
if (cce(c, blocked)) {
|
||||
model_converter::entry * new_entry = 0;
|
||||
block_covered_clause(c, blocked, new_entry);
|
||||
s.m_num_covered_clauses++;
|
||||
}
|
||||
}
|
||||
for (clause* c : m_to_remove) {
|
||||
s.remove_clause(*c);
|
||||
}
|
||||
m_to_remove.reset();
|
||||
}
|
||||
|
||||
void process(literal l) {
|
||||
|
@ -1085,6 +1137,7 @@ namespace sat {
|
|||
return;
|
||||
}
|
||||
|
||||
literal blocked = null_literal;
|
||||
m_to_remove.reset();
|
||||
{
|
||||
clause_use_list & occs = s.m_use_list.get(l);
|
||||
|
@ -1095,14 +1148,10 @@ namespace sat {
|
|||
SASSERT(c.contains(l));
|
||||
s.mark_all_but(c, l);
|
||||
if (all_tautology(l)) {
|
||||
s.unmark_all(c);
|
||||
block_clause(c, l, new_entry);
|
||||
s.m_num_blocked_clauses++;
|
||||
}
|
||||
else if (cce(c, l)) {
|
||||
block_covered_clause(c, l, new_entry);
|
||||
s.m_num_covered_clauses++;
|
||||
}
|
||||
s.unmark_all(c);
|
||||
it.next();
|
||||
}
|
||||
}
|
||||
|
@ -1127,8 +1176,9 @@ namespace sat {
|
|||
block_binary(it, l, new_entry);
|
||||
s.m_num_blocked_clauses++;
|
||||
}
|
||||
else if (cce(l, l2)) {
|
||||
block_covered_binary(it, l, new_entry);
|
||||
else if (cce(l, l2, blocked)) {
|
||||
model_converter::entry * blocked_entry = 0;
|
||||
block_covered_binary(it, l, blocked, blocked_entry);
|
||||
s.m_num_covered_clauses++;
|
||||
}
|
||||
else {
|
||||
|
@ -1163,9 +1213,9 @@ namespace sat {
|
|||
mc.insert(*new_entry, m_covered_clause, m_elim_stack);
|
||||
}
|
||||
|
||||
void prepare_block_binary(watch_list::iterator it, literal l, model_converter::entry *& new_entry) {
|
||||
void prepare_block_binary(watch_list::iterator it, literal l, literal blocked, model_converter::entry *& new_entry) {
|
||||
if (new_entry == 0)
|
||||
new_entry = &(mc.mk(model_converter::BLOCK_LIT, l.var()));
|
||||
new_entry = &(mc.mk(model_converter::BLOCK_LIT, blocked.var()));
|
||||
literal l2 = it->get_literal();
|
||||
TRACE("blocked_clause", tout << "new blocked clause: " << l2 << " " << l << "\n";);
|
||||
s.remove_bin_clause_half(l2, l, it->is_learned());
|
||||
|
@ -1173,12 +1223,12 @@ namespace sat {
|
|||
}
|
||||
|
||||
void block_binary(watch_list::iterator it, literal l, model_converter::entry *& new_entry) {
|
||||
prepare_block_binary(it, l, new_entry);
|
||||
prepare_block_binary(it, l, l, new_entry);
|
||||
mc.insert(*new_entry, l, it->get_literal());
|
||||
}
|
||||
|
||||
void block_covered_binary(watch_list::iterator it, literal l, model_converter::entry *& new_entry) {
|
||||
prepare_block_binary(it, l, new_entry);
|
||||
void block_covered_binary(watch_list::iterator it, literal l, literal blocked, model_converter::entry *& new_entry) {
|
||||
prepare_block_binary(it, l, blocked, new_entry);
|
||||
mc.insert(*new_entry, m_covered_clause, m_elim_stack);
|
||||
}
|
||||
|
||||
|
|
|
@ -57,10 +57,26 @@ namespace sat {
|
|||
c2 = m.mk_exists(2, c1);
|
||||
SASSERT(c2 == ((v0 && v1) || v1 || !v0));
|
||||
}
|
||||
|
||||
void test4() {
|
||||
bdd_manager m(3);
|
||||
bdd v0 = m.mk_var(0);
|
||||
bdd v1 = m.mk_var(1);
|
||||
bdd v2 = m.mk_var(2);
|
||||
bdd c1 = (v0 && v2) || v1;
|
||||
std::cout << "before reorder:\n";
|
||||
std::cout << c1 << "\n";
|
||||
std::cout << c1.bdd_size() << "\n";
|
||||
m.try_reorder();
|
||||
std::cout << "after reorder:\n";
|
||||
std::cout << c1 << "\n";
|
||||
std::cout << c1.bdd_size() << "\n";
|
||||
}
|
||||
}
|
||||
|
||||
void tst_bdd() {
|
||||
sat::test1();
|
||||
sat::test2();
|
||||
sat::test3();
|
||||
sat::test4();
|
||||
}
|
||||
|
|
Loading…
Reference in a new issue