mirrors/z3
3
0
Fork 0
mirror of https://github.com/Z3Prover/z3 synced 2025-08-15 07:15:26 +00:00
Code Activity

updates to ac-plugin

Browse source 
fix incrementality bugs by allowing destructive updates during saturation at the cost of redoing saturation after a pop.
This commit is contained in:
Nikolaj Bjorner 2025-07-27 13:38:24 -07:00
parent 07613942da
commit 67695b4cd6
5 changed files with 263 additions and 195 deletions
Download patch file Download diff file Expand all files Collapse all files

424
src/ast/euf/euf_ac_plugin.cpp
View file

@ -14,7 +14,7 @@ Author:
Nikolaj Bjorner (nbjorner) 2023-11-11
Completion modulo AC
E set of eqs
pick critical pair xy = z by j1 xu = v by j2 in E
Add new equation zu = xyu = vy by j1, j2
@ -22,7 +22,7 @@ Completion modulo AC
Sets P - processed, R - reductions, S - to simplify
new equality l = r:
new equality l = r:
reduce l = r modulo R if equation is external
orient l = r - if it cannot be oriented, discard
if l = r is a reduction rule then reduce R, S using l = r, insert into R
@ -46,9 +46,9 @@ backward subsumption e as (l = r) using (l' = r') in P u S:
is reduction rule e as (l = r):
l is a unit, and r is unit, is empty, or is zero.
superpose e as (l = r) with (l' = r') in P:
if l and l' share a common subset x.
if l and l' share a common subset x.
forward simplify (l' = r') in P u S using e as (l = r):
@ -56,10 +56,10 @@ forward simplify (l' = r') in P u S using e as (l = r):
More notes:
Justifications for new equations are joined (requires extension to egraph/justification)
Process new merges so use list is updated
Justifications for processed merges are recorded
Updated equations are recorded for restoration on backtracking
Keep track of foreign / shared occurrences of AC functions.
@ -91,7 +91,7 @@ More notes:
TODOs:
- Efficiency of handling shared terms.
- The shared terms hash table is not incremental.
- The shared terms hash table is not incremental.
It could be made incremental by updating it on every merge similar to how the egraph handles it.
- V2 using multiplicities instead of repeated values in monomials.
- Squash trail updates when equations or monomials are modified within the same epoch.
@ -131,20 +131,18 @@ namespace euf {
return;
for (auto arg : enode_args(n))
if (is_op(arg))
register_shared(arg);
register_shared(arg);
}
// unit -> {}
void ac_plugin::add_unit(enode* u) {
m_units.push_back(u);
mk_node(u);
auto m_id = to_monomial(u, {});
init_equation(eq(to_monomial(u), m_id, justification::axiom(get_id())));
void ac_plugin::add_unit(enode* u) {
push_equation(u, nullptr);
}
// zero x -> zero
void ac_plugin::add_zero(enode* z) {
mk_node(z)->is_zero = true;
// zeros persist
}
void ac_plugin::register_shared(enode* n) {
@ -165,12 +163,16 @@ namespace euf {
push_undo(is_register_shared);
}
void ac_plugin::push_scope_eh() {
push_undo(is_push_scope);
}
void ac_plugin::undo() {
auto k = m_undo.back();
m_undo.pop_back();
switch (k) {
case is_add_eq: {
m_active.pop_back();
case is_queue_eq: {
m_queued.pop_back();
break;
}
case is_add_node: {
@ -180,14 +182,15 @@ namespace euf {
n->~node();
break;
}
case is_add_monomial: {
m_monomials.pop_back();
case is_push_scope: {
m_active.reset();
m_passive.reset();
m_units.reset();
m_queue_head = 0;
break;
}
case is_update_eq: {
auto const& [idx, eq] = m_update_eq_trail.back();
m_active[idx] = eq;
m_update_eq_trail.pop_back();
case is_add_monomial: {
m_monomials.pop_back();
break;
}
case is_add_shared_index: {
@ -203,7 +206,7 @@ namespace euf {
break;
}
case is_register_shared: {
auto s = m_shared.back();
auto s = m_shared.back();
m_shared_nodes[s.n->get_id()] = false;
m_shared.pop_back();
break;
@ -316,14 +319,24 @@ namespace euf {
}
void ac_plugin::merge_eh(enode* l, enode* r) {
if (l == r)
return;
push_equation(l, r);
}
void ac_plugin::pop_equation(enode* l, enode* r) {
m_fuel += m_fuel_inc;
auto j = justification::equality(l, r);
auto m1 = to_monomial(l);
auto m2 = to_monomial(r);
TRACE(plugin, tout << "merge: " << m_name << " " << g.bpp(l) << " == " << g.bpp(r) << " " << m_pp_ll(*this, monomial(m1)) << " == " << m_pp_ll(*this, monomial(m2)) << "\n");
init_equation(eq(m1, m2, j));
if (!r) {
m_units.push_back(l);
mk_node(l);
auto m_id = to_monomial(l, {});
init_equation(eq(to_monomial(l), m_id, justification::axiom(get_id())), true);
}
else {
auto j = justification::equality(l, r);
auto m1 = to_monomial(l);
auto m2 = to_monomial(r);
TRACE(plugin, tout << "merge: " << m_name << " " << g.bpp(l) << " == " << g.bpp(r) << " " << m_pp_ll(*this, monomial(m1)) << " == " << m_pp_ll(*this, monomial(m2)) << "\n");
init_equation(eq(m1, m2, j), true);
}
}
void ac_plugin::diseq_eh(enode* eq) {
@ -336,64 +349,83 @@ namespace euf {
register_shared(b);
}
bool ac_plugin::init_equation(eq const& e) {
m_active.push_back(e);
auto& eq = m_active.back();
deduplicate(monomial(eq.l).m_nodes, monomial(eq.r).m_nodes);
if (orient_equation(eq)) {
auto& ml = monomial(eq.l);
auto& mr = monomial(eq.r);
unsigned eq_id = m_active.size() - 1;
if (ml.size() == 1 && mr.size() == 1)
push_merge(ml[0]->n, mr[0]->n, eq.j);
for (auto n : ml) {
if (!n->n->is_marked2()) {
n->eqs.push_back(eq_id);
n->n->mark2();
push_undo(is_add_eq_index);
m_node_trail.push_back(n);
for (auto s : n->shared)
m_shared_todo.insert(s);
}
}
for (auto n : mr) {
if (!n->n->is_marked2()) {
n->eqs.push_back(eq_id);
n->n->mark2();
push_undo(is_add_eq_index);
m_node_trail.push_back(n);
for (auto s : n->shared)
m_shared_todo.insert(s);
}
}
for (auto n : ml)
n->n->unmark2();
for (auto n : mr)
n->n->unmark2();
SASSERT(well_formed(eq));
TRACE(plugin, display_equation_ll(tout, eq) << " shared: " << m_shared_todo << "\n");
m_to_simplify_todo.insert(eq_id);
m_new_eqs.push_back(eq_id);
//display_equation_ll(verbose_stream() << "init " << eq_id << ": ", eq) << "\n";
return true;
}
else {
m_active.pop_back();
return false;
}
void ac_plugin::push_equation(enode* l, enode* r) {
if (l == r)
return;
m_queued.push_back({ l, r });
push_undo(is_queue_eq);
}
bool ac_plugin::init_equation(eq eq, bool is_active) {
deduplicate(monomial(eq.l), monomial(eq.r));
if (!orient_equation(eq))
return false;
#if 0
if (is_reducing(eq))
is_active = true;
#endif
is_active = true; // set to active because forward reduction is not implemented yet.
// we will have to forward reduce a passive equation before it can be activated.
// this means that we have to iterate over all overlaps of variables in equation with
// reducing eqations. Otherwise, we will not have the invariant that reducing variables
// are eliminated from all equations.
if (!is_active) {
m_passive.push_back(eq);
return true;
}
m_active.push_back(eq);
auto& ml = monomial(eq.l);
auto& mr = monomial(eq.r);
unsigned eq_id = m_active.size() - 1;
if (ml.size() == 1 && mr.size() == 1)
push_merge(ml[0]->n, mr[0]->n, eq.j);
for (auto n : ml) {
if (!n->n->is_marked2()) {
n->eqs.push_back(eq_id);
n->n->mark2();
push_undo(is_add_eq_index);
m_node_trail.push_back(n);
for (auto s : n->shared)
m_shared_todo.insert(s);
}
}
for (auto n : mr) {
if (!n->n->is_marked2()) {
n->eqs.push_back(eq_id);
n->n->mark2();
push_undo(is_add_eq_index);
m_node_trail.push_back(n);
for (auto s : n->shared)
m_shared_todo.insert(s);
}
}
for (auto n : ml)
n->n->unmark2();
for (auto n : mr)
n->n->unmark2();
SASSERT(well_formed(eq));
TRACE(plugin, display_equation_ll(tout, eq) << " shared: " << m_shared_todo << "\n");
m_to_simplify_todo.insert(eq_id);
m_new_eqs.push_back(eq_id);
//display_equation_ll(verbose_stream() << "init " << eq_id << ": ", eq) << "\n";
return true;
}
bool ac_plugin::orient_equation(eq& e) {
auto& ml = monomial(e.l);
auto& mr = monomial(e.r);
@ -402,7 +434,7 @@ namespace euf {
if (ml.size() < mr.size()) {
std::swap(e.l, e.r);
return true;
}
}
else {
sort(ml);
sort(mr);
@ -412,7 +444,7 @@ namespace euf {
if (ml[i]->id() < mr[i]->id())
std::swap(e.l, e.r);
return true;
}
}
return false;
}
}
@ -429,7 +461,7 @@ namespace euf {
return false;
if (!is_sorted(mr))
return false;
for (unsigned i = 0; i < ml.size(); ++i) {
for (unsigned i = 0; i < ml.size(); ++i) {
if (ml[i]->id() == mr[i]->id())
continue;
if (ml[i]->id() < mr[i]->id())
@ -455,15 +487,21 @@ namespace euf {
uint64_t ac_plugin::filter(monomial_t& m) {
auto& bloom = m.m_bloom;
if (bloom.m_tick == m_tick)
if (bloom.m_tick == m_tick) {
uint64_t f = 0;
for (auto n : m)
f |= (1ull << (n->id() % 64ull));
SASSERT(f == bloom.m_filter);
return bloom.m_filter;
}
bloom.m_filter = 0;
for (auto n : m)
bloom.m_filter |= (1ull << (n->id() % 64ull));
if (!is_sorted(m))
sort(m);
bloom.m_tick = m_tick;
return bloom.m_filter;
return bloom.m_filter;
}
bool ac_plugin::can_be_subset(monomial_t& subset, monomial_t& superset) {
@ -501,10 +539,10 @@ namespace euf {
ns.push_back(n);
for (unsigned i = 0; i < ns.size(); ++i) {
auto k = ns[i];
if (is_op(k))
ns.append(k->num_args(), k->args());
else
m.push_back(mk_node(k));
if (is_op(k))
ns.append(k->num_args(), k->args());
else
m.push_back(mk_node(k));
}
return to_monomial(n, m);
}
@ -562,6 +600,10 @@ namespace euf {
}
void ac_plugin::propagate() {
while (m_queue_head < m_queued.size()) {
auto [l, r] = m_queued[m_queue_head++];
pop_equation(l, r);
}
while (true) {
loop_start:
if (m_fuel == 0)
@ -575,15 +617,15 @@ namespace euf {
SASSERT(well_formed(m_active[eq_id]));
// simplify eq using processed
TRACE(plugin,
for (auto other_eq : forward_iterator(eq_id))
tout << "forward iterator " << eq_id << " vs " << other_eq << " " << is_processed(other_eq) << "\n");
TRACE(plugin,
for (auto other_eq : forward_iterator(eq_id))
tout << "forward iterator " << eq_id << " vs " << other_eq << " " << is_processed(other_eq) << "\n");
for (auto other_eq : forward_iterator(eq_id))
if (is_processed(other_eq) && forward_simplify(eq_id, other_eq))
goto loop_start;
auto& eq = m_active[eq_id];
deduplicate(monomial(eq.l).m_nodes, monomial(eq.r).m_nodes);
deduplicate(monomial(eq.l), monomial(eq.r));
if (monomial(eq.l).size() == 0) {
set_status(eq_id, eq_status::is_dead_eq);
continue;
@ -605,8 +647,8 @@ namespace euf {
for (auto other_eq : backward_iterator(eq_id))
if (is_active(other_eq))
backward_simplify(eq_id, other_eq);
forward_subsume_new_eqs();
forward_subsume_new_eqs();
// superpose, create new equations
unsigned new_sup = 0;
for (auto other_eq : superpose_iterator(eq_id))
@ -623,12 +665,20 @@ namespace euf {
}
unsigned ac_plugin::pick_next_eq() {
init_pick:
while (!m_to_simplify_todo.empty()) {
unsigned id = *m_to_simplify_todo.begin();
if (id < m_active.size() && is_to_simplify(id))
return id;
m_to_simplify_todo.remove(id);
}
if (!m_passive.empty()) {
auto eq = m_passive.back();
verbose_stream() << "pick passive " << eq_pp_ll(*this, eq) << "\n";
m_passive.pop_back();
init_equation(eq, true);
goto init_pick;
}
return UINT_MAX;
}
@ -637,14 +687,10 @@ namespace euf {
auto& eq = m_active[id];
if (eq.status == eq_status::is_dead_eq)
return;
if (are_equal(monomial(eq.l), monomial(eq.r)))
if (are_equal(monomial(eq.l), monomial(eq.r)))
s = eq_status::is_dead_eq;
if (eq.status != s) {
m_update_eq_trail.push_back({ id, eq });
eq.status = s;
push_undo(is_update_eq);
}
eq.status = s;
switch (s) {
case eq_status::is_processed_eq:
case eq_status::is_reducing_eq:
@ -657,7 +703,7 @@ namespace euf {
set_status(id, eq_status::is_dead_eq);
}
break;
}
}
}
//
@ -673,7 +719,7 @@ namespace euf {
}
//
// backward iterator allows simplification of eq
// forward iterator allows simplification of eq
// The rhs of eq is a super-set of lhs of other eq.
//
unsigned_vector const& ac_plugin::forward_iterator(unsigned eq_id) {
@ -733,7 +779,7 @@ namespace euf {
unsigned j = 0;
m_eq_seen.reserve(m_active.size() + 1, false);
for (unsigned i = 0; i < m_eq_occurs.size(); ++i) {
unsigned id = m_eq_occurs[i];
unsigned id = m_eq_occurs[i];
if (m_eq_seen[id])
continue;
if (id == eq_id)
@ -749,7 +795,7 @@ namespace euf {
}
//
// forward iterator simplifies other eqs where their rhs is a superset of lhs of eq
// backward iterator simplifies other eqs where their rhs is a superset of lhs of eq
//
unsigned_vector const& ac_plugin::backward_iterator(unsigned eq_id) {
auto& eq = m_active[eq_id];
@ -768,7 +814,7 @@ namespace euf {
}
void ac_plugin::init_ref_counts(monomial_t const& monomial, ref_counts& counts) const {
init_ref_counts(monomial.m_nodes, counts);
init_ref_counts(monomial.m_nodes, counts);
}
void ac_plugin::init_ref_counts(ptr_vector<node> const& monomial, ref_counts& counts) const {
@ -786,7 +832,7 @@ namespace euf {
init_ref_counts(m, check);
return
all_of(counts, [&](unsigned i) { return check[i] == counts[i]; }) &&
all_of(check, [&](unsigned i) { return check[i] == counts[i]; });
all_of(check, [&](unsigned i) { return check[i] == counts[i]; });
}
void ac_plugin::backward_simplify(unsigned src_eq, unsigned dst_eq) {
@ -843,10 +889,8 @@ namespace euf {
reduce(m_src_r, j);
auto new_r = to_monomial(m_src_r);
index_new_r(dst_eq, monomial(m_active[dst_eq].r), monomial(new_r));
m_update_eq_trail.push_back({ dst_eq, m_active[dst_eq] });
m_active[dst_eq].r = new_r;
m_active[dst_eq].j = j;
push_undo(is_update_eq);
m_src_r.reset();
m_src_r.append(monomial(src.r).m_nodes);
TRACE(plugin_verbose, tout << "rewritten to " << m_pp_ll(*this, monomial(new_r)) << "\n");
@ -862,7 +906,7 @@ namespace euf {
//
// dst_ids, dst_count contain rhs of dst_eq
//
TRACE(plugin, tout << "backward simplify " << eq_pp_ll(*this, src) << " " << eq_pp_ll(*this, dst) << " can-be-subset: " << can_be_subset(monomial(src.l), monomial(dst.r)) << "\n");
TRACE(plugin, tout << "forward simplify " << eq_pp_ll(*this, src) << " " << eq_pp_ll(*this, dst) << " can-be-subset: " << can_be_subset(monomial(src.l), monomial(dst.r)) << "\n");
if (forward_subsumes(src_eq, dst_eq)) {
set_status(dst_eq, eq_status::is_dead_eq);
@ -873,11 +917,11 @@ namespace euf {
// check that src.l is a subset of dst.r
if (!can_be_subset(monomial(src.l), monomial(dst.r)))
return false;
if (!is_subset(m_dst_r_counts, m_src_l_counts, monomial(src.l)))
return false;
if (monomial(dst.r).size() == 0)
return false;
if (!is_subset(m_dst_r_counts, m_src_l_counts, monomial(src.l)))
return false;
if (monomial(dst.r).size() == 0)
return false;
SASSERT(is_correct_ref_count(monomial(dst.r), m_dst_r_counts));
@ -885,17 +929,15 @@ namespace euf {
init_ref_counts(monomial(src.l), m_src_l_counts);
//verbose_stream() << "forward simplify " << eq_pp_ll(*this, src_eq) << " for " << eq_pp_ll(*this, dst_eq) << "\n";
rewrite1(m_src_l_counts, monomial(src.r), m_dst_r_counts, m);
auto j = justify_rewrite(src_eq, dst_eq);
reduce(m, j);
auto new_r = to_monomial(m);
index_new_r(dst_eq, monomial(m_active[dst_eq].r), monomial(new_r));
m_update_eq_trail.push_back({ dst_eq, m_active[dst_eq] });
m_active[dst_eq].r = new_r;
m_active[dst_eq].j = j;
TRACE(plugin, tout << "rewritten to " << m_pp(*this, monomial(new_r)) << "\n");
push_undo(is_update_eq);
return true;
}
@ -913,7 +955,7 @@ namespace euf {
m_new_eqs.reset();
}
bool ac_plugin::is_forward_subsumed(unsigned eq_id) {
bool ac_plugin::is_forward_subsumed(unsigned eq_id) {
return any_of(forward_iterator(eq_id), [&](unsigned other_eq) { return forward_subsumes(other_eq, eq_id); });
}
@ -968,14 +1010,16 @@ namespace euf {
}
// now dst.r and src.r should align and have the same elements.
// since src.r is a subset of dst.r we iterate over dst.r
if (!all_of(monomial(src.r), [&](node* n) {
unsigned id = n->id();
if (!all_of(monomial(src.r), [&](node* n) {
unsigned id = n->id();
return m_src_r_counts[id] == m_dst_r_counts[id]; })) {
TRACE(plugin_verbose, tout << "dst.r and src.r do not align\n");
SASSERT(!are_equal(m_active[src_eq], m_active[dst_eq]));
return false;
}
return all_of(monomial(dst.r), [&](node* n) { unsigned id = n->id(); return m_src_r_counts[id] == m_dst_r_counts[id]; });
bool r = all_of(monomial(dst.r), [&](node* n) { unsigned id = n->id(); return m_src_r_counts[id] == m_dst_r_counts[id]; });
SASSERT(r || !are_equal(m_active[src_eq], m_active[dst_eq]));
return r;
}
// src_l_counts, src_r_counts are initialized for src.l, src.r
@ -990,7 +1034,7 @@ namespace euf {
return false;
unsigned size_diff = monomial(dst.l).size() - monomial(src.l).size();
if (size_diff != monomial(dst.r).size() - monomial(src.r).size())
return false;
return false;
if (!is_superset(m_src_l_counts, m_dst_l_counts, monomial(dst.l)))
return false;
if (!is_superset(m_src_r_counts, m_dst_r_counts, monomial(dst.r)))
@ -1026,14 +1070,14 @@ namespace euf {
unsigned dst_count = dst_counts[id];
unsigned src_count = src_l[id];
SASSERT(dst_count > 0);
if (src_count == 0) {
dst[j++] = n;
dst[j++] = n;
}
else if (src_count < dst_count) {
dst[j++] = n;
dst_counts.dec(id, 1);
}
}
}
dst.shrink(j);
dst.append(src_r.m_nodes);
@ -1047,11 +1091,11 @@ namespace euf {
init_loop:
if (m.size() == 1)
return change;
bloom b;
bloom b;
init_ref_counts(m, m_m_counts);
for (auto n : m) {
if (n->is_zero) {
m[0] = n;
m[0] = n;
m.shrink(1);
break;
}
@ -1060,9 +1104,9 @@ namespace euf {
if (!is_reducing(eq)) // also can use processed?
continue;
auto& src = m_active[eq];
if (!is_equation_oriented(src))
continue;
if (!is_equation_oriented(src))
continue;
if (!can_be_subset(monomial(src.l), m, b))
continue;
if (!is_subset(m_m_counts, m_eq_counts, monomial(src.l)))
@ -1078,9 +1122,8 @@ namespace euf {
change = true;
goto init_loop;
}
}
}
while (false);
}
} while (false);
VERIFY(sz >= m.size());
return change;
}
@ -1122,7 +1165,7 @@ namespace euf {
auto& src = m_active[src_eq];
auto& dst = m_active[dst_eq];
unsigned max_left = std::max(monomial(src.l).size(), monomial(dst.l).size());
unsigned max_left = std::max(monomial(src.l).size(), monomial(dst.l).size());
unsigned min_right = std::max(monomial(src.r).size(), monomial(dst.r).size());
@ -1151,7 +1194,7 @@ namespace euf {
m_src_r.shrink(src_r_size);
return false;
}
// compute CD
for (auto n : monomial(src.l)) {
unsigned id = n->id();
@ -1171,18 +1214,18 @@ namespace euf {
reduce(m_src_r, j);
deduplicate(m_src_r, m_dst_r);
bool added_eq = false;
auto src_r = src.r;
unsigned max_left_new = std::max(m_src_r.size(), m_dst_r.size());
unsigned min_right_new = std::min(m_src_r.size(), m_dst_r.size());
if (max_left_new <= max_left && min_right_new <= min_right)
added_eq = init_equation(eq(to_monomial(m_src_r), to_monomial(m_dst_r), j));
if (max_left_new <= max_left && min_right_new <= min_right)
added_eq = init_equation(eq(to_monomial(m_src_r), to_monomial(m_dst_r), j), false);
CTRACE(plugin, added_eq,
tout << "superpose: " << m_name << " " << eq_pp_ll(*this, src) << " " << eq_pp_ll(*this, dst) << " --> ";
tout << m_pp_ll(*this, m_src_r) << "== " << m_pp_ll(*this, m_dst_r) << "\n";);
tout << m_pp_ll(*this, m_src_r) << "== " << m_pp_ll(*this, m_dst_r) << "\n";);
m_src_r.reset();
m_src_r.append(monomial(src_r).m_nodes);
return added_eq;
@ -1191,7 +1234,7 @@ namespace euf {
bool ac_plugin::is_reducing(eq const& e) const {
auto const& l = monomial(e.l);
auto const& r = monomial(e.r);
return l.size() == 1 && r.size() <= 1;
return l.size() == 1 && r.size() <= 1;
}
void ac_plugin::backward_reduce(unsigned eq_id) {
@ -1204,21 +1247,24 @@ namespace euf {
}
}
// TODO: this is destructive. It breaks reversibility.
// TODO: also need justifications from eq if there is a change.
void ac_plugin::backward_reduce(eq const& eq, unsigned other_eq_id) {
auto& other_eq = m_active[other_eq_id];
auto& other_eq = m_active[other_eq_id];
TRACE(plugin_verbose,
tout << "backward reduce " << eq_pp_ll(*this, eq) << " " << eq_pp_ll(*this, other_eq) << "\n");
bool change = false;
if (backward_reduce_monomial(eq, monomial(other_eq.l)))
if (backward_reduce_monomial(eq, other_eq, monomial(other_eq.l)))
change = true;
if (backward_reduce_monomial(eq, monomial(other_eq.r)))
if (backward_reduce_monomial(eq, other_eq, monomial(other_eq.r)))
change = true;
if (change)
set_status(other_eq_id, eq_status::is_to_simplify_eq);
CTRACE(plugin, change,
tout << "backward reduce " << eq_pp_ll(*this, eq) << " " << eq_pp_ll(*this, other_eq) << "\n");
if (change) {
set_status(other_eq_id, eq_status::is_to_simplify_eq);
}
}
bool ac_plugin::backward_reduce_monomial(eq const& eq, monomial_t& m) {
auto const& r = monomial(eq.r);
bool ac_plugin::backward_reduce_monomial(eq const& src, eq& dst, monomial_t& m) {
auto const& r = monomial(src.r);
unsigned j = 0;
bool change = false;
for (auto n : m) {
@ -1241,7 +1287,11 @@ namespace euf {
m.m_nodes[j++] = r[0];
}
m.m_nodes.shrink(j);
return change;
if (change) {
m.m_bloom.m_tick = 0;
dst.j = join(dst.j, src);
}
return change;
}
bool ac_plugin::are_equal(monomial_t& a, monomial_t& b) {
@ -1252,8 +1302,8 @@ namespace euf {
if (a.size() != b.size())
return false;
m_eq_counts.reset();
for (auto n : a)
m_eq_counts.inc(n->id(), 1);
for (auto n : a)
m_eq_counts.inc(n->id(), 1);
for (auto n : b) {
unsigned id = n->id();
if (m_eq_counts[id] == 0)
@ -1277,21 +1327,29 @@ namespace euf {
return true;
}
void ac_plugin::deduplicate(monomial_t& a, monomial_t& b) {
unsigned sza = a.size(), szb = b.size();
deduplicate(a.m_nodes, b.m_nodes);
if (sza != a.size())
a.m_bloom.m_tick = 0;
if (szb != b.size())
b.m_bloom.m_tick = 0;
}
void ac_plugin::deduplicate(ptr_vector<node>& a, ptr_vector<node>& b) {
{
for (auto n : a) {
if (n->is_zero) {
a[0] = n;
a.shrink(1);
break;
}
for (auto n : a) {
if (n->is_zero) {
a[0] = n;
a.shrink(1);
break;
}
for (auto n : b) {
if (n->is_zero) {
b[0] = n;
b.shrink(1);
break;
}
}
for (auto n : b) {
if (n->is_zero) {
b[0] = n;
b.shrink(1);
break;
}
}
@ -1340,14 +1398,14 @@ namespace euf {
while (!m_shared_todo.empty()) {
auto idx = *m_shared_todo.begin();
m_shared_todo.remove(idx);
if (idx < m_shared.size())
if (idx < m_shared.size())
simplify_shared(idx, m_shared[idx]);
}
m_monomial_table.reset();
for (auto const& s1 : m_shared) {
shared s2;
TRACE(plugin_verbose, tout << "shared " << s1.m << ": " << m_pp_ll(*this, monomial(s1.m)) << "\n");
if (!m_monomial_table.find(s1.m, s2))
if (!m_monomial_table.find(s1.m, s2))
m_monomial_table.insert(s1.m, s1);
else if (s2.n->get_root() != s1.n->get_root()) {
TRACE(plugin, tout << "merge shared " << g.bpp(s1.n->get_root()) << " and " << g.bpp(s2.n->get_root()) << "\n");
@ -1380,14 +1438,12 @@ namespace euf {
}
}
for (auto n : monomial(old_m))
n->n->unmark2();
n->n->unmark2();
m_update_shared_trail.push_back({ idx, s });
push_undo(is_update_shared);
m_shared[idx].m = new_m;
m_shared[idx].j = j;
TRACE(plugin_verbose, tout << "shared simplified to " << m_pp_ll(*this, monomial(new_m)) << "\n");
push_merge(old_n, new_n, j);
}
@ -1397,19 +1453,15 @@ namespace euf {
}
justification::dependency* ac_plugin::justify_equation(unsigned eq) {
auto const& e = m_active[eq];
auto* j = m_dep_manager.mk_leaf(e.j);
j = justify_monomial(j, monomial(e.l));
j = justify_monomial(j, monomial(e.r));
return j;
}
justification::dependency* ac_plugin::justify_monomial(justification::dependency* j, monomial_t const& m) {
return j;
return m_dep_manager.mk_leaf(m_active[eq].j);
}
justification ac_plugin::join(justification j, unsigned eq) {
return justification::dependent(m_dep_manager.mk_join(m_dep_manager.mk_leaf(j), justify_equation(eq)));
}
justification ac_plugin::join(justification j, eq const& eq) {
return justification::dependent(m_dep_manager.mk_join(m_dep_manager.mk_leaf(j), m_dep_manager.mk_leaf(eq.j)));
}
}

24
src/ast/euf/euf_ac_plugin.h
View file

@ -123,6 +123,7 @@ namespace euf {
func_decl* m_decl = nullptr;
bool m_is_injective = false;
vector<eq> m_active, m_passive;
enode_pair_vector m_queued;
ptr_vector<node> m_nodes;
bool_vector m_shared_nodes;
vector<monomial_t> m_monomials;
@ -146,21 +147,21 @@ namespace euf {
// backtrackable state
enum undo_kind {
is_add_eq,
is_queue_eq,
is_add_monomial,
is_add_node,
is_update_eq,
is_add_shared_index,
is_add_eq_index,
is_register_shared,
is_update_shared
is_update_shared,
is_push_scope
};
svector<undo_kind> m_undo;
ptr_vector<node> m_node_trail;
unsigned m_queue_head = 0;
svector<std::pair<unsigned, shared>> m_update_shared_trail;
svector<std::tuple<node*, unsigned, unsigned>> m_merge_trail;
svector<std::pair<unsigned, eq>> m_update_eq_trail;
@ -191,8 +192,8 @@ namespace euf {
bool well_formed(eq const& e) const;
bool is_reducing(eq const& e) const;
void backward_reduce(unsigned eq_id);
void backward_reduce(eq const& src, unsigned dst);
bool backward_reduce_monomial(eq const& eq, monomial_t& m);
void backward_reduce(eq const& eq, unsigned dst);
bool backward_reduce_monomial(eq const& src, eq & dst, monomial_t& m);
void forward_subsume_new_eqs();
bool is_forward_subsumed(unsigned dst_eq);
bool forward_subsumes(unsigned src_eq, unsigned dst_eq);
@ -207,8 +208,10 @@ namespace euf {
UNREACHABLE();
return nullptr;
}
bool init_equation(eq const& e);
bool init_equation(eq e, bool is_active);
void push_equation(enode* l, enode* r);
void pop_equation(enode* l, enode* r);
bool orient_equation(eq& e);
void set_status(unsigned eq_id, eq_status s);
unsigned pick_next_eq();
@ -217,6 +220,7 @@ namespace euf {
void backward_simplify(unsigned eq_id, unsigned using_eq);
bool forward_simplify(unsigned eq_id, unsigned using_eq);
bool superpose(unsigned src_eq, unsigned dst_eq);
void deduplicate(monomial_t& a, monomial_t& b);
void deduplicate(ptr_vector<node>& a, ptr_vector<node>& b);
ptr_vector<node> m_src_r, m_src_l, m_dst_r, m_dst_l;
@ -260,8 +264,8 @@ namespace euf {
justification justify_rewrite(unsigned eq1, unsigned eq2);
justification::dependency* justify_equation(unsigned eq);
justification::dependency* justify_monomial(justification::dependency* d, monomial_t const& m);
justification join(justification j1, unsigned eq);
justification join(justification j1, eq const& eq);
bool is_correct_ref_count(monomial_t const& m, ref_counts const& counts) const;
bool is_correct_ref_count(ptr_vector<node> const& m, ref_counts const& counts) const;
@ -301,6 +305,8 @@ namespace euf {
void undo() override;
void push_scope_eh() override;
void propagate() override;
std::ostream& display(std::ostream& out) const override;

5
src/ast/euf/euf_arith_plugin.h
View file

@ -43,6 +43,11 @@ namespace euf {
void undo() override;
void push_scope_eh() override {
m_add.push_scope_eh();
m_mul.push_scope_eh();
}
void propagate() override;
std::ostream& display(std::ostream& out) const override;

3
src/ast/euf/euf_egraph.cpp
View file

@ -103,6 +103,9 @@ namespace euf {
m_scopes.push_back(m_updates.size());
m_region.push_scope();
m_updates.push_back(update_record(m_new_th_eqs_qhead, update_record::new_th_eq_qhead()));
for (auto p : m_plugins)
if (p)
p->push_scope_eh();
}
SASSERT(m_new_th_eqs_qhead <= m_new_th_eqs.size());
}

2
src/ast/euf/euf_plugin.h
View file

@ -52,6 +52,8 @@ namespace euf {
virtual void propagate() = 0;
virtual void undo() = 0;
virtual void push_scope_eh() {}
virtual std::ostream& display(std::ostream& out) const = 0;