mirror of
https://github.com/Z3Prover/z3
synced 2025-04-16 13:58:45 +00:00
adding bdd package
Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner
parent
64ea473bc7
commit
d7b6373601
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@ -32,10 +32,16 @@ namespace sat {
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}
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}
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// add two dummy nodes for true_bdd and false_bdd
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m_nodes.push_back(bdd_node(0,0,0));
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m_nodes.push_back(bdd_node(0,0,0));
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m_nodes[0].m_refcount = max_rc;
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m_nodes[1].m_refcount = max_rc;
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for (unsigned i = 0; i <= bdd_no_op; ++i) {
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m_nodes.push_back(bdd_node(0,0,0));
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m_nodes.back().m_refcount = max_rc;
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m_nodes.back().m_index = m_nodes.size()-1;
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}
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m_spare_entry = nullptr;
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m_max_num_bdd_nodes = 1 << 24; // up to 16M nodes
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m_mark_level = 0;
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alloc_free_nodes(1024);
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// add variables
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for (unsigned i = 0; i < num_vars; ++i) {
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@ -45,28 +51,44 @@ namespace sat {
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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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}
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m_spare_entry = nullptr;
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}
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}
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bdd_manager::~bdd_manager() {
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if (m_spare_entry) {
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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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m_alloc.deallocate(sizeof(*e), e);
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}
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}
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bdd_manager::BDD bdd_manager::apply_const(BDD a, BDD b, bdd_op op) {
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SASSERT(is_const(a) && is_const(b));
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switch (op) {
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case bdd_and_op:
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return (a == 1 && b == 1) ? 1 : 0;
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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 == 1 || b == 1) ? 1 : 0;
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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) ? 1 : 0;
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return (a == b) ? true_bdd : false_bdd;
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default:
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UNREACHABLE();
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return 0;
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return false_bdd;
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}
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}
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bdd_manager::BDD bdd_manager::apply(BDD arg1, BDD arg2, bdd_op op) {
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return apply_rec(arg1, arg2, op);
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bool first = true;
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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 (bdd_exception) {
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try_reorder();
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if (!first) throw;
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first = false;
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}
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}
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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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@ -95,11 +117,17 @@ namespace sat {
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if (is_const(a) && is_const(b)) {
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return m_apply_const[a + 2*b + 4*op];
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}
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cache_entry * e1 = pop_entry(hash2(a, b, op));
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cache_entry const* e2 = m_cache.insert_if_not_there(e1);
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if (e2->m_op == op && e2->m_bdd1 == a && e2->m_bdd2 == b) {
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push_entry(e1);
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return e2->m_result;
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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 (e2 != e1) {
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if (e2->m_bdd1 == a && e2->m_bdd2 == b && e2->m_op == op) {
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push_entry(e1);
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return e2->m_result;
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}
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e1 = const_cast<op_entry*>(e2);
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e1->m_bdd1 = a;
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e1->m_bdd2 = b;
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e1->m_op = op;
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}
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BDD r;
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if (level(a) == level(b)) {
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@ -107,7 +135,7 @@ namespace sat {
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push(apply_rec(hi(a), hi(b), op));
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r = make_node(level(a), read(2), read(1));
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}
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else if (level(a) < level(b)) {
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else if (level(a) > level(b)) {
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push(apply_rec(lo(a), b, op));
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push(apply_rec(hi(a), b, op));
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r = make_node(level(a), read(2), read(1));
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@ -117,10 +145,8 @@ namespace sat {
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push(apply_rec(a, hi(b), op));
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r = make_node(level(b), read(2), read(1));
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}
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pop(2);
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e1->m_result = r;
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e1->m_bdd1 = a;
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e1->m_bdd2 = b;
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e1->m_op = op;
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return r;
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}
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@ -136,46 +162,63 @@ namespace sat {
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return m_bdd_stack[m_bdd_stack.size() - index];
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}
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bdd_manager::cache_entry* bdd_manager::pop_entry(unsigned hash) {
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cache_entry* result = 0;
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bdd_manager::op_entry* bdd_manager::pop_entry(BDD l, BDD r, BDD op) {
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op_entry* result = nullptr;
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if (m_spare_entry) {
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result = m_spare_entry;
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m_spare_entry = 0;
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result->m_hash = hash;
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m_spare_entry = nullptr;
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result->m_bdd1 = l;
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result->m_bdd2 = r;
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result->m_op = op;
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}
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else {
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void * mem = m_alloc.allocate(sizeof(cache_entry));
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result = new (mem) cache_entry(hash);
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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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}
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result->m_result = -1;
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return result;
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}
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void bdd_manager::push_entry(cache_entry* e) {
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void bdd_manager::push_entry(op_entry* e) {
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SASSERT(!m_spare_entry);
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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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if (l == r) {
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return l;
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}
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#if 0
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// TBD
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unsigned hash = node_hash(level, l, r);
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bdd result = m_
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#endif
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int sz = m_nodes.size();
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m_nodes.push_back(bdd_node(level, l, r));
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return sz;
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bdd_node n(level, l, r);
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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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}
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e->get_data().m_refcount = 0;
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if (m_free_nodes.empty()) {
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gc();
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e = m_node_table.insert_if_not_there2(n);
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e->get_data().m_refcount = 0;
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}
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if (m_free_nodes.empty()) {
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if (m_nodes.size() > m_max_num_bdd_nodes) {
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throw bdd_exception();
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}
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e->get_data().m_index = m_nodes.size();
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m_nodes.push_back(e->get_data());
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alloc_free_nodes(m_nodes.size()/2);
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}
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else {
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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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}
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return e->get_data().m_index;
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}
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#if 0
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void bdd_manager::bdd_reorder(int) {
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void bdd_manager::try_reorder() {
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// TBD
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}
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#endif
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bdd bdd_manager::mk_var(unsigned i) {
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return bdd(m_var2bdd[2*i+1], this);
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@ -185,76 +228,301 @@ namespace sat {
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return bdd(m_var2bdd[2*i+1], this);
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}
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unsigned bdd_manager::hash2(BDD a, BDD b, bdd_op op) const {
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return mk_mix(a, b, op);
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}
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bdd bdd_manager::mk_not(bdd b) {
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return bdd(mk_not_rec(b.root), this);
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bool first = true;
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while (true) {
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try {
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return bdd(mk_not_rec(b.root), this);
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}
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catch (bdd_exception) {
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try_reorder();
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if (!first) throw;
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first = false;
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}
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}
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}
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bdd_manager::BDD bdd_manager::mk_not_rec(BDD b) {
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if (is_true(b)) return false_bdd;
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if (is_false(b)) return true_bdd;
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cache_entry* e1 = pop_entry(hash1(b, bdd_not_op));
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cache_entry const* e2 = m_cache.insert_if_not_there(e1);
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if (e2->m_bdd1 == b && e2->m_op == bdd_not_op) {
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push_entry(e1);
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return e2->m_result;
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op_entry* e1 = pop_entry(b, b, bdd_not_op);
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op_entry const* e2 = m_op_cache.insert_if_not_there(e1);
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if (e2 != e1) {
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if (e2->m_bdd1 == b && e2->m_bdd2 == b && e2->m_op == bdd_not_op) {
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push_entry(e1);
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return e2->m_result;
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}
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e1 = const_cast<op_entry*>(e2);
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e1->m_bdd1 = b;
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e1->m_bdd2 = b;
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e1->m_op = bdd_not_op;
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}
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push(mk_not_rec(lo(b)));
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push(mk_not_rec(hi(b)));
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BDD r = make_node(level(b), read(2), read(1));
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pop(2);
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e1->m_bdd1 = b;
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e1->m_bdd2 = b;
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e1->m_op = bdd_not_op;
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e1->m_result = r;
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return r;
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}
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#if 0
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bdd bdd_manager::mk_exists(bdd vars, bdd b) {
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bdd bdd_manager::mk_ite(bdd const& c, bdd const& t, bdd const& e) {
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bool first = true;
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while (true) {
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try {
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return bdd(mk_ite_rec(c.root, t.root, e.root), this);
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}
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catch (bdd_exception) {
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try_reorder();
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if (!first) throw;
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first = false;
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}
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}
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}
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bdd_manager::BDD bdd_manager::mk_ite_rec(BDD a, BDD b, BDD c) {
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if (is_true(a)) return b;
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if (is_false(a)) return c;
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if (b == c) return b;
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if (is_true(b)) return apply(a, c, bdd_or_op);
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if (is_false(c)) return apply(a, b, bdd_and_op);
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if (is_false(b)) return apply(mk_not_rec(a), c, bdd_and_op);
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if (is_true(c)) return apply(mk_not_rec(a), b, bdd_or_op);
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SASSERT(!is_const(a) && !is_const(b) && !is_const(c));
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op_entry * e1 = pop_entry(a, b, c);
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op_entry const* e2 = m_op_cache.insert_if_not_there(e1);
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if (e2 != e1) {
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if (e2->m_bdd1 == a && e2->m_bdd2 == b && e2->m_op == c) {
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push_entry(e1);
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return e2->m_result;
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}
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e1 = const_cast<op_entry*>(e2);
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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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}
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unsigned la = level(a), lb = level(b), lc = level(c);
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BDD r;
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BDD a1, b1, c1, a2, b2, c2;
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unsigned lvl = la;
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if (la >= lb && la >= lc) {
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a1 = lo(a), a2 = hi(a);
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lvl = la;
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}
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else {
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a1 = a, a2 = a;
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}
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if (lb >= la && lb >= lc) {
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b1 = lo(b), b2 = hi(b);
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lvl = lb;
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}
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else {
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b1 = b, b2 = b;
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}
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if (lc >= la && lc >= lb) {
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c1 = lo(c), c2 = hi(c);
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lvl = lc;
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}
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else {
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c1 = c, c2 = c;
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}
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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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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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return bdd(mk_quant(n, vars, b.root, bdd_or_op), this);
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}
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bdd bdd_manager::mk_forall(unsigned n, unsigned const* vars, bdd const& b) {
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return bdd(mk_quant(n, vars, b.root, bdd_and_op), this);
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}
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bdd_manager::BDD bdd_manager::mk_quant(unsigned n, unsigned const* vars, BDD b, bdd_op op) {
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BDD result = b;
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for (unsigned i = 0; i < n; ++i) {
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result = mk_quant_rec(m_var2level[vars[i]], result, op);
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}
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return result;
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}
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bdd_manager::BDD bdd_manager::mk_quant_rec(unsigned l, BDD b, bdd_op op) {
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unsigned lvl = level(b);
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if (lvl == l) {
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return apply(lo(b), hi(b), op);
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}
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else if (lvl < l) {
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return b;
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}
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else {
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BDD a = level2bdd(l);
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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 (e1 != e2) {
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if (e2->m_bdd1 == a && e2->m_bdd2 == b && e2->m_op == q_op) {
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push_entry(e1);
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return e2->m_result;
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}
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e1 = const_cast<op_entry*>(e2);
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e1->m_bdd1 = a;
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e1->m_bdd2 = b;
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e1->m_op = q_op;
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}
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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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BDD r = make_node(lvl, read(2), read(1));
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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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}
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double bdd_manager::path_count(bdd const& b) {
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init_mark();
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m_path_count.resize(m_nodes.size());
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m_path_count[0] = 0;
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m_path_count[1] = 1;
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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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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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m_todo.push_back(lo(r));
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}
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else if (!is_marked(hi(r))) {
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m_todo.push_back(hi(r));
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}
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else {
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m_path_count[r] = m_path_count[lo(r)] + m_path_count[hi(r)];
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set_mark(r);
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m_todo.pop_back();
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}
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}
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return m_path_count[b.root];
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}
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bdd bdd_manager::mk_forall(bdd vars, bdd b) {
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void bdd_manager::alloc_free_nodes(unsigned n) {
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for (unsigned i = 0; i < n; ++i) {
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m_free_nodes.push_back(m_nodes.size());
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m_nodes.push_back(bdd_node());
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m_nodes.back().m_index = m_nodes.size() - 1;
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}
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m_free_nodes.reverse();
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}
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bdd bdd_manager::mk_ite(bdd c, bdd t, bdd e) {
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void bdd_manager::gc() {
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IF_VERBOSE(1, verbose_stream() << "(bdd :gc " << m_nodes.size() << ")\n";);
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SASSERT(m_free_nodes.empty());
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svector<bool> reachable(m_nodes.size(), false);
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for (unsigned i = m_bdd_stack.size(); i-- > 0; ) {
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reachable[m_bdd_stack[i]] = true;
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m_todo.push_back(m_bdd_stack[i]);
|
||||
}
|
||||
for (unsigned i = m_nodes.size(); i-- > 2; ) {
|
||||
if (m_nodes[i].m_refcount > 0) {
|
||||
reachable[i] = true;
|
||||
m_todo.push_back(i);
|
||||
}
|
||||
}
|
||||
while (!m_todo.empty()) {
|
||||
BDD b = m_todo.back();
|
||||
m_todo.pop_back();
|
||||
SASSERT(reachable[b]);
|
||||
if (is_const(b)) continue;
|
||||
if (!reachable[lo(b)]) {
|
||||
reachable[lo(b)] = true;
|
||||
m_todo.push_back(lo(b));
|
||||
}
|
||||
if (!reachable[hi(b)]) {
|
||||
reachable[hi(b)] = true;
|
||||
m_todo.push_back(hi(b));
|
||||
}
|
||||
}
|
||||
for (unsigned i = m_nodes.size(); i-- > 2; ) {
|
||||
if (!reachable[i]) {
|
||||
m_free_nodes.push_back(i);
|
||||
}
|
||||
}
|
||||
for (auto* e : m_op_cache) {
|
||||
m_alloc.deallocate(sizeof(*e), e);
|
||||
}
|
||||
m_op_cache.reset();
|
||||
m_node_table.reset();
|
||||
// re-populate node cache
|
||||
for (unsigned i = m_nodes.size(); i-- > 2; ) {
|
||||
if (reachable[i]) {
|
||||
SASSERT(m_nodes[i].m_index == i);
|
||||
m_node_table.insert(m_nodes[i]);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
double bdd_manager::path_count(bdd b) {
|
||||
|
||||
void bdd_manager::init_mark() {
|
||||
m_mark.resize(m_nodes.size());
|
||||
++m_mark_level;
|
||||
if (m_mark_level == 0) {
|
||||
m_mark.fill(0);
|
||||
}
|
||||
}
|
||||
|
||||
#endif
|
||||
|
||||
std::ostream& bdd_manager::display(std::ostream& out, bdd b) {
|
||||
|
||||
std::ostream& bdd_manager::display(std::ostream& out, bdd const& b) {
|
||||
init_mark();
|
||||
m_todo.push_back(b.root);
|
||||
while (!m_todo.empty()) {
|
||||
BDD r = m_todo.back();
|
||||
if (is_marked(r)) {
|
||||
m_todo.pop_back();
|
||||
}
|
||||
else if (lo(r) == 0 && hi(r) == 0) {
|
||||
set_mark(r);
|
||||
m_todo.pop_back();
|
||||
}
|
||||
else if (!is_marked(lo(r))) {
|
||||
m_todo.push_back(lo(r));
|
||||
}
|
||||
else if (!is_marked(hi(r))) {
|
||||
m_todo.push_back(hi(r));
|
||||
}
|
||||
else {
|
||||
out << r << " : " << var(r) << " " << lo(r) << " " << hi(r) << "\n";
|
||||
set_mark(r);
|
||||
m_todo.pop_back();
|
||||
}
|
||||
}
|
||||
return out;
|
||||
}
|
||||
|
||||
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.m_lo == 0 && n.m_hi == 0) continue;
|
||||
out << i << " : " << m_level2var[n.m_level] << " " << n.m_lo << " " << n.m_hi << "\n";
|
||||
}
|
||||
return out;
|
||||
}
|
||||
|
||||
bdd::bdd(int root, bdd_manager* m):
|
||||
root(root), m(m) {
|
||||
m->inc_ref(root);
|
||||
}
|
||||
|
||||
bdd::bdd(int 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() { m->dec_ref(root); }
|
||||
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); }
|
||||
std::ostream& bdd::display(std::ostream& out) const { return m->display(out, *this); }
|
||||
|
||||
|
||||
bdd::~bdd() {
|
||||
m->dec_ref(root);
|
||||
std::ostream& operator<<(std::ostream& out, bdd const& b) {
|
||||
return b.display(out);
|
||||
}
|
||||
|
||||
#if 0
|
||||
#endif
|
||||
|
||||
|
||||
}
|
||||
|
|
|
|||
|
|
@ -42,20 +42,29 @@ namespace sat {
|
|||
public:
|
||||
bdd(bdd & other);
|
||||
~bdd();
|
||||
// bdd operator!() { return m->mk_not(*this); }
|
||||
bdd operator!();
|
||||
bdd operator&&(bdd const& other);
|
||||
bdd operator||(bdd const& other);
|
||||
std::ostream& display(std::ostream& out) const;
|
||||
bool operator==(bdd const& other) const { return root == other.root; }
|
||||
bool operator!=(bdd const& other) const { return root != other.root; }
|
||||
};
|
||||
|
||||
std::ostream& operator<<(std::ostream& out, bdd const& b);
|
||||
|
||||
class bdd_manager {
|
||||
friend bdd;
|
||||
|
||||
typedef int BDD;
|
||||
|
||||
enum bdd_op {
|
||||
bdd_and_op = 0,
|
||||
bdd_or_op,
|
||||
bdd_iff_op,
|
||||
bdd_not_op,
|
||||
bdd_no_op
|
||||
bdd_and_op = 2,
|
||||
bdd_or_op = 3,
|
||||
bdd_iff_op = 4,
|
||||
bdd_not_op = 5,
|
||||
bdd_and_proj_op = 6,
|
||||
bdd_or_proj_op = 7,
|
||||
bdd_no_op = 8,
|
||||
};
|
||||
|
||||
struct bdd_node {
|
||||
|
|
@ -63,71 +72,99 @@ namespace sat {
|
|||
m_refcount(0),
|
||||
m_level(level),
|
||||
m_lo(lo),
|
||||
m_hi(hi)
|
||||
m_hi(hi),
|
||||
m_index(0)
|
||||
{}
|
||||
bdd_node(): m_level(0), m_lo(0), m_hi(0), m_index(0) {}
|
||||
unsigned m_refcount : 10;
|
||||
unsigned m_level : 22;
|
||||
int m_lo;
|
||||
int m_hi;
|
||||
//unsigned m_hash;
|
||||
//unsigned m_next;
|
||||
unsigned m_index;
|
||||
unsigned hash() const { return mk_mix(m_level, m_lo, m_hi); }
|
||||
};
|
||||
|
||||
struct hash_node {
|
||||
unsigned operator()(bdd_node const& n) const { return n.hash(); }
|
||||
};
|
||||
|
||||
struct eq_node {
|
||||
bool operator()(bdd_node const& a, bdd_node const& b) const {
|
||||
return a.m_lo == b.m_lo && a.m_hi == b.m_hi && a.m_level == b.m_level;
|
||||
}
|
||||
};
|
||||
|
||||
struct cache_entry {
|
||||
cache_entry(unsigned hash):
|
||||
m_bdd1(0),
|
||||
m_bdd2(0),
|
||||
m_op(bdd_no_op),
|
||||
m_result(0),
|
||||
m_hash(hash)
|
||||
typedef hashtable<bdd_node, hash_node, eq_node> node_table;
|
||||
|
||||
struct op_entry {
|
||||
op_entry(BDD l, BDD r, BDD op):
|
||||
m_bdd1(l),
|
||||
m_bdd2(r),
|
||||
m_op(op),
|
||||
m_result(0)
|
||||
{}
|
||||
|
||||
BDD m_bdd1;
|
||||
BDD m_bdd2;
|
||||
bdd_op m_op;
|
||||
BDD m_op;
|
||||
BDD m_result;
|
||||
unsigned m_hash;
|
||||
unsigned hash() const { return mk_mix(m_bdd1, m_bdd2, m_op); }
|
||||
};
|
||||
|
||||
struct hash_entry {
|
||||
unsigned operator()(cache_entry* e) const { return e->m_hash; }
|
||||
unsigned operator()(op_entry* e) const { return e->hash(); }
|
||||
};
|
||||
|
||||
struct eq_entry {
|
||||
bool operator()(cache_entry * a, cache_entry * b) const {
|
||||
return a->m_hash == b->m_hash;
|
||||
bool operator()(op_entry * a, op_entry * b) const {
|
||||
return a->hash() == b->hash();
|
||||
}
|
||||
};
|
||||
|
||||
svector<bdd_node> m_nodes;
|
||||
ptr_hashtable<cache_entry, hash_entry, eq_entry> m_cache;
|
||||
typedef ptr_hashtable<op_entry, hash_entry, eq_entry> op_table;
|
||||
|
||||
svector<bdd_node> m_nodes;
|
||||
op_table m_op_cache;
|
||||
node_table m_node_table;
|
||||
unsigned_vector m_apply_const;
|
||||
svector<BDD> m_bdd_stack;
|
||||
cache_entry* m_spare_entry;
|
||||
op_entry* m_spare_entry;
|
||||
svector<BDD> m_var2bdd;
|
||||
unsigned_vector m_var2level, m_level2var;
|
||||
unsigned_vector m_free_nodes;
|
||||
small_object_allocator m_alloc;
|
||||
mutable svector<unsigned> m_mark;
|
||||
mutable unsigned m_mark_level;
|
||||
mutable svector<double> m_path_count;
|
||||
mutable svector<BDD> m_todo;
|
||||
|
||||
unsigned m_max_num_bdd_nodes;
|
||||
|
||||
BDD make_node(unsigned level, BDD l, BDD r);
|
||||
|
||||
BDD apply_const(BDD a, BDD b, bdd_op op);
|
||||
BDD apply(BDD arg1, BDD arg2, bdd_op op);
|
||||
BDD mk_quant(unsigned n, unsigned const* vars, BDD b, bdd_op op);
|
||||
|
||||
BDD apply_rec(BDD arg1, BDD arg2, bdd_op op);
|
||||
BDD mk_not_rec(BDD b);
|
||||
BDD mk_ite_rec(BDD a, BDD b, BDD c);
|
||||
BDD mk_quant_rec(unsigned lvl, BDD b, bdd_op op);
|
||||
|
||||
void push(BDD b);
|
||||
void pop(unsigned num_scopes);
|
||||
BDD read(unsigned index);
|
||||
|
||||
cache_entry* pop_entry(unsigned hash);
|
||||
void push_entry(cache_entry* e);
|
||||
op_entry* pop_entry(BDD l, BDD r, BDD op);
|
||||
void push_entry(op_entry* e);
|
||||
|
||||
// void bdd_reorder(int);
|
||||
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; }
|
||||
|
||||
BDD mk_not_rec(BDD b);
|
||||
|
||||
unsigned hash1(BDD b, bdd_op op) const { return hash2(b, b, op); }
|
||||
unsigned hash2(BDD a, BDD b, bdd_op op) const;
|
||||
unsigned hash3(BDD a, BDD b, BDD c, bdd_op op) const;
|
||||
void try_reorder();
|
||||
|
||||
static const BDD false_bdd = 0;
|
||||
static const BDD true_bdd = 1;
|
||||
|
|
@ -136,33 +173,33 @@ namespace sat {
|
|||
inline bool is_true(BDD b) const { return b == true_bdd; }
|
||||
inline bool is_false(BDD b) const { return b == false_bdd; }
|
||||
inline bool is_const(BDD b) const { return 0 <= b && b <= 1; }
|
||||
inline unsigned level(BDD b) const { return m_nodes[b].m_level; }
|
||||
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 BDD level2bdd(unsigned l) const { return m_var2bdd[m_level2var[l]]; }
|
||||
|
||||
unsigned level(BDD b) const { return m_nodes[b].m_level; }
|
||||
BDD lo(BDD b) const { return m_nodes[b].m_lo; }
|
||||
BDD hi(BDD b) const { return m_nodes[b].m_hi; }
|
||||
void inc_ref(BDD b) { if (m_nodes[b].m_refcount != max_rc) m_nodes[b].m_refcount++; }
|
||||
void dec_ref(BDD b) { if (m_nodes[b].m_refcount != max_rc && m_nodes[b].m_refcount > 0) m_nodes[b].m_refcount--; }
|
||||
|
||||
BDD mk_true() { return 1; }
|
||||
BDD mk_false() { return 0; }
|
||||
|
||||
struct bdd_exception {};
|
||||
public:
|
||||
bdd_manager(unsigned nodes, unsigned cache_size);
|
||||
~bdd_manager();
|
||||
|
||||
bdd mk_var(unsigned i);
|
||||
bdd mk_nvar(unsigned i);
|
||||
|
||||
bdd mk_not(bdd b);
|
||||
bdd mk_exist(bdd vars, bdd b);
|
||||
bdd mk_forall(bdd vars, bdd b);
|
||||
bdd mk_and(bdd a, bdd b) { return bdd(apply(a.root, b.root, bdd_and_op), this); }
|
||||
bdd mk_or(bdd a, bdd b) { return bdd(apply(a.root, b.root, bdd_or_op), this); }
|
||||
bdd mk_iff(bdd a, bdd b) { return bdd(apply(a.root, b.root, bdd_iff_op), this); }
|
||||
bdd mk_ite(bdd c, bdd t, bdd e);
|
||||
bdd mk_exists(unsigned n, unsigned const* vars, bdd const & b);
|
||||
bdd mk_forall(unsigned n, unsigned const* vars, bdd const & b);
|
||||
bdd mk_and(bdd const& a, bdd const& b) { return bdd(apply(a.root, b.root, bdd_and_op), this); }
|
||||
bdd mk_or(bdd const& a, bdd const& b) { return bdd(apply(a.root, b.root, bdd_or_op), this); }
|
||||
bdd mk_iff(bdd const& a, bdd const& b) { return bdd(apply(a.root, b.root, bdd_iff_op), this); }
|
||||
bdd mk_ite(bdd const& c, bdd const& t, bdd const& e);
|
||||
|
||||
double path_count(bdd b);
|
||||
double path_count(bdd const& b);
|
||||
|
||||
std::ostream& display(std::ostream& out, bdd b);
|
||||
std::ostream& display(std::ostream& out, bdd const& b);
|
||||
std::ostream& display(std::ostream& out);
|
||||
};
|
||||
}
|
||||
|
|
|
|||
|
|
@ -16,6 +16,7 @@ add_executable(test-z3
|
|||
arith_rewriter.cpp
|
||||
arith_simplifier_plugin.cpp
|
||||
ast.cpp
|
||||
bdd.cpp
|
||||
bit_blaster.cpp
|
||||
bits.cpp
|
||||
bit_vector.cpp
|
||||
|
|
|
|||
40
src/test/bdd.cpp
Normal file
40
src/test/bdd.cpp
Normal file
|
|
@ -0,0 +1,40 @@
|
|||
#include "sat/sat_bdd.h"
|
||||
|
||||
namespace sat {
|
||||
static void test1() {
|
||||
bdd_manager m(20, 1000);
|
||||
bdd v0 = m.mk_var(0);
|
||||
bdd v1 = m.mk_var(1);
|
||||
bdd v2 = m.mk_var(2);
|
||||
bdd c1 = v0 && v1 && v2;
|
||||
bdd c2 = v2 && v0 && v1;
|
||||
std::cout << c1 << "\n";
|
||||
SASSERT(c1 == c2);
|
||||
|
||||
c1 = v0 || v1 || v2;
|
||||
c2 = v2 || v1 || v0;
|
||||
std::cout << c1 << "\n";
|
||||
std::cout << c2 << "\n";
|
||||
SASSERT(c1 == c2);
|
||||
}
|
||||
|
||||
static void test2() {
|
||||
bdd_manager m(20, 1000);
|
||||
bdd v0 = m.mk_var(0);
|
||||
bdd v1 = m.mk_var(1);
|
||||
bdd v2 = m.mk_var(2);
|
||||
SASSERT(m.mk_ite(v0,v0,v1) == (v0 || v1));
|
||||
SASSERT(m.mk_ite(v0,v1,v1) == v1);
|
||||
SASSERT(m.mk_ite(v1,v0,v1) == (v0 && v1));
|
||||
SASSERT(m.mk_ite(v1,v0,v0) == v0);
|
||||
SASSERT(m.mk_ite(v0,!v0,v1) == (!v0 && v1));
|
||||
SASSERT(m.mk_ite(v0,v1,!v0) == (!v0 || v1));
|
||||
SASSERT(!(v0 && v1) == (!v0 || !v1));
|
||||
SASSERT(!(v0 || v1) == (!v0 && !v1));
|
||||
}
|
||||
}
|
||||
|
||||
void tst_bdd() {
|
||||
sat::test1();
|
||||
sat::test2();
|
||||
}
|
||||
|
|
@ -245,6 +245,7 @@ int main(int argc, char ** argv) {
|
|||
TST_ARGV(sat_lookahead);
|
||||
TST_ARGV(sat_local_search);
|
||||
TST_ARGV(cnf_backbones);
|
||||
TST(bdd);
|
||||
//TST_ARGV(hs);
|
||||
}
|
||||
|
||||
|
|
|
|||
Loading…
Reference in a new issue