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arrays (#4684)

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* arrays

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

* arrays

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

* na

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

* arrays

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

* na

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

* fill

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

* update drat and fix euf bugs

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

* na

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

* na

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

* na

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

* const qualifiers

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

* na

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

* reorg ba

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

* reorg

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

* build warnings

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2020-09-13 19:29:59 -07:00 • committed by GitHub
parent d56dd1db7b
commit 796e2fd9eb
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79 changed files with 2571 additions and 1850 deletions
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129
src/sat/smt/array_axioms.cpp
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@ -27,6 +27,8 @@ namespace array {
m_axiom_trail.push_back(r);
if (m_axioms.contains(idx))
m_axiom_trail.pop_back();
else
ctx.push(push_back_vector<euf::solver, svector<axiom_record>>(m_axiom_trail));
}
bool solver::assert_axiom(unsigned idx) {
@ -39,10 +41,16 @@ namespace array {
app* select;
switch (r.m_kind) {
case axiom_record::kind_t::is_store:
TRACE("array", tout << "store-axiom: " << mk_bounded_pp(child, m, 2) << "\n";);
return assert_store_axiom(to_app(child));
case axiom_record::kind_t::is_select:
select = r.select->get_app();
SASSERT(a.is_select(select));
SASSERT(can_beta_reduce(r.n));
TRACE("array", tout << "select-axiom: " << mk_bounded_pp(select, m, 2) << " " << mk_bounded_pp(child, m, 2) << "\n";);
if (r.select->get_arg(0)->get_root() != r.n->get_root()) {
IF_VERBOSE(0, verbose_stream() << "could delay " << mk_pp(select, m) << " " << mk_pp(child, m) << "\n");
}
if (a.is_const(child))
return assert_select_const_axiom(select, to_app(child));
else if (a.is_as_array(child))
@ -57,20 +65,22 @@ namespace array {
UNREACHABLE();
break;
case axiom_record::kind_t::is_default:
SASSERT(can_beta_reduce(r.n));
TRACE("array", tout << "default-axiom: " << mk_bounded_pp(child, m, 2) << "\n";);
if (a.is_const(child))
return assert_default_const_axiom(to_app(child));
else if (a.is_store(child))
return assert_default_store_axiom(to_app(child));
else if (a.is_map(child))
return assert_default_map_axiom(to_app(child));
else if (a.is_as_array(child))
return assert_default_as_array_axiom(to_app(child));
else
UNREACHABLE();
return true;
break;
case axiom_record::kind_t::is_extensionality:
TRACE("array", tout << "extensionality-axiom: " << mk_bounded_pp(child, m, 2) << "\n";);
return assert_extensionality(r.n->get_arg(0)->get_expr(), r.n->get_arg(1)->get_expr());
case axiom_record::kind_t::is_congruence:
TRACE("array", tout << "congruence-axiom: " << mk_bounded_pp(child, m, 2) << " " << mk_bounded_pp(r.select->get_expr(), m, 2) << "\n";);
return assert_congruent_axiom(child, r.select->get_expr());
default:
UNREACHABLE();
@ -86,7 +96,7 @@ namespace array {
* n := store(a, i, v)
*/
bool solver::assert_store_axiom(app* e) {
m_stats.m_num_store_axiom++;
++m_stats.m_num_store_axiom;
SASSERT(a.is_store(e));
unsigned num_args = e->get_num_args();
ptr_vector<expr> sel_args(num_args - 1, e->get_args());
@ -104,7 +114,7 @@ namespace array {
* where i = (i_1, ..., i_n), j = (j_1, .., j_n), k in 1..n
*/
bool solver::assert_select_store_axiom(app* select, app* store) {
m_stats.m_num_select_store_axiom++;
++m_stats.m_num_select_store_axiom;
SASSERT(a.is_store(store));
SASSERT(a.is_select(select));
SASSERT(store->get_num_args() == 1 + select->get_num_args());
@ -126,7 +136,10 @@ namespace array {
if (s1->get_root() == s2->get_root())
return false;
sat::literal sel_eq = b_internalize(sel_eq_e);
if (s().value(sel_eq) == l_true)
return false;
bool new_prop = false;
for (unsigned i = 1; i < num_args; i++) {
expr* idx1 = store->get_arg(i);
expr* idx2 = select->get_arg(i);
@ -135,13 +148,15 @@ namespace array {
if (r1 == r2)
continue;
if (m.are_distinct(r1->get_expr(), r2->get_expr())) {
new_prop = true;
add_clause(sel_eq);
break;
}
sat::literal idx_eq = b_internalize(m.mk_eq(idx1, idx2));
add_clause(idx_eq, sel_eq);
if (add_clause(idx_eq, sel_eq))
new_prop = true;
}
return true;
return new_prop;
}
/**
@ -149,7 +164,7 @@ namespace array {
* select(const(v), i) = v
*/
bool solver::assert_select_const_axiom(app* select, app* cnst) {
m_stats.m_num_select_const_axiom++;
++m_stats.m_num_select_const_axiom;
expr* val = nullptr;
VERIFY(a.is_const(cnst, val));
SASSERT(a.is_select(select));
@ -167,7 +182,7 @@ namespace array {
* e1 = e2 or select(e1, diff(e1,e2)) != select(e2, diff(e1, e2))
*/
bool solver::assert_extensionality(expr* e1, expr* e2) {
m_stats.m_num_extensionality_axiom++;
++m_stats.m_num_extensionality_axiom;
func_decl_ref_vector* funcs = nullptr;
VERIFY(m_sort2diff.find(m.get_sort(e1), funcs));
expr_ref_vector args1(m), args2(m);
@ -184,10 +199,7 @@ namespace array {
expr_ref sel1_eq_sel2(m.mk_eq(sel1, sel2), m);
literal lit1 = b_internalize(n1_eq_n2);
literal lit2 = b_internalize(sel1_eq_sel2);
if (s().value(lit1) == l_true || s().value(lit2) == l_false)
return false;
add_clause(lit1, ~lit2);
return true;
return add_clause(lit1, ~lit2);
}
/**
@ -195,17 +207,12 @@ namespace array {
* select(map[f](a, ... d), i) = f(select(a,i),...,select(d,i))
*/
bool solver::assert_select_map_axiom(app* select, app* map) {
m_stats.m_num_select_map_axiom++;
++m_stats.m_num_select_map_axiom;
SASSERT(a.is_map(map));
SASSERT(a.is_select(select));
SASSERT(map->get_num_args() > 0);
func_decl* f = a.get_map_func_decl(map);
TRACE("array",
tout << mk_bounded_pp(map, m) << "\n";
tout << mk_bounded_pp(select, m) << "\n";);
unsigned num_args = select->get_num_args();
unsigned num_arrays = map->get_num_args();
ptr_buffer<expr> args1, args2;
vector<ptr_vector<expr> > args2l;
args1.push_back(map);
@ -238,7 +245,7 @@ namespace array {
* select(as-array f, i_1, ..., i_n) = (f i_1 ... i_n)
*/
bool solver::assert_select_as_array_axiom(app* select, app* arr) {
m_stats.m_num_select_as_array_axiom++;
++m_stats.m_num_select_as_array_axiom;
SASSERT(a.is_as_array(arr));
SASSERT(a.is_select(select));
unsigned num_args = select->get_num_args();
@ -257,39 +264,31 @@ namespace array {
* default(map[f](a,..,d)) = f(default(a),..,default(d))
*/
bool solver::assert_default_map_axiom(app* map) {
m_stats.m_num_default_map_axiom++;
++m_stats.m_num_default_map_axiom;
SASSERT(a.is_map(map));
func_decl* f = a.get_map_func_decl(map);
SASSERT(map->get_num_args() == f->get_arity());
ptr_buffer<expr> args2;
expr_ref_vector args2(m);
for (expr* arg : *map)
args2.push_back(a.mk_default(arg));
expr_ref def1(a.mk_default(map), m);
expr_ref def2(m.mk_app(f, args2), m);
rewrite(def2);
return ctx.propagate(e_internalize(def1), e_internalize(def2), array_axiom());
}
/**
* Assert:
* default(const(e)) = e
*/
bool solver::assert_default_const_axiom(app* cnst) {
m_stats.m_num_default_const_axiom++;
++m_stats.m_num_default_const_axiom;
expr* val = nullptr;
VERIFY(a.is_const(cnst, val));
TRACE("array", tout << mk_bounded_pp(cnst, m) << "\n";);
expr_ref def(a.mk_default(cnst), m);
return ctx.propagate(expr2enode(val), e_internalize(def), array_axiom());
}
bool solver::assert_default_as_array_axiom(app* as_array) {
// no-op
return false;
}
/**
* let n := store(a, i, v)
@ -303,19 +302,15 @@ namespace array {
* default(n) = default(a)
*/
bool solver::assert_default_store_axiom(app* store) {
m_stats.m_num_default_store_axiom++;
++m_stats.m_num_default_store_axiom;
SASSERT(a.is_store(store));
SASSERT(store->get_num_args() >= 3);
expr_ref def1(m), def2(m);
bool prop = false;
unsigned num_args = store->get_num_args();
def1 = a.mk_default(store);
def2 = a.mk_default(store->get_arg(0));
bool is_new = false;
if (has_unitary_domain(store)) {
def2 = store->get_arg(num_args - 1);
}
@ -357,6 +352,7 @@ namespace array {
* Assert select(lambda xs . M, N1,.., Nk) -> M[N1/x1, ..., Nk/xk]
*/
bool solver::assert_select_lambda_axiom(app* select, expr* lambda) {
++m_stats.m_num_select_lambda_axiom;
SASSERT(is_lambda(lambda));
SASSERT(a.is_select(select));
SASSERT(m.get_sort(lambda) == m.get_sort(select->get_arg(0)));
@ -373,8 +369,8 @@ namespace array {
*/
bool solver::assert_congruent_axiom(expr* e1, expr* e2) {
++m_stats.m_num_congruence_axiom;
sort* s = m.get_sort(e1);
unsigned dimension = get_array_arity(s);
sort* srt = m.get_sort(e1);
unsigned dimension = get_array_arity(srt);
expr_ref n1_eq_n2(m.mk_eq(e1, e2), m);
expr_ref_vector args1(m), args2(m);
args1.push_back(e1);
@ -382,10 +378,10 @@ namespace array {
svector<symbol> names;
sort_ref_vector sorts(m);
for (unsigned i = 0; i < dimension; i++) {
sort * srt = get_array_domain(s, i);
sorts.push_back(srt);
sort * asrt = get_array_domain(srt, i);
sorts.push_back(asrt);
names.push_back(symbol(i));
expr * k = m.mk_var(dimension - i - 1, srt);
expr * k = m.mk_var(dimension - i - 1, asrt);
args1.push_back(k);
args2.push_back(k);
}
@ -395,8 +391,8 @@ namespace array {
expr_ref q(m.mk_forall(dimension, sorts.c_ptr(), names.c_ptr(), eq), m);
rewrite(q);
sat::literal fa_eq = b_internalize(q);
add_clause(~b_internalize(n1_eq_n2), fa_eq);
return true;
sat::literal neq = b_internalize(n1_eq_n2);
return add_clause(~neq, fa_eq);
}
bool solver::has_unitary_domain(app* array_term) {
@ -411,7 +407,7 @@ namespace array {
return true;
}
bool solver::has_large_domain(app* array_term) {
bool solver::has_large_domain(expr* array_term) {
SASSERT(a.is_array(array_term));
sort* s = m.get_sort(array_term);
unsigned dim = get_array_arity(s);
@ -429,7 +425,6 @@ namespace array {
return false;
}
std::pair<app*, func_decl*> solver::mk_epsilon(sort* s) {
app* eps = nullptr;
func_decl* diag = nullptr;
@ -444,24 +439,16 @@ namespace array {
return std::make_pair(eps, diag);
}
void solver::push_parent_select_store_axioms(theory_var v) {
expr* e = var2expr(v);
if (!a.is_array(e))
return;
auto& d = get_var_data(v);
for (euf::enode* store : d.m_parents)
if (a.is_store(store->get_expr()))
for (euf::enode* sel : d.m_parents)
if (a.is_select(sel->get_expr()))
push_axiom(select_axiom(sel, store));
}
bool solver::add_delayed_axioms() {
if (!get_config().m_array_delay_exp_axiom)
return false;
unsigned num_vars = get_num_vars();
for (unsigned v = 0; v < num_vars; v++)
push_parent_select_store_axioms(v);
for (unsigned v = 0; v < num_vars; v++) {
propagate_parent_select_axioms(v);
auto& d = get_var_data(v);
if (d.m_prop_upward)
propagate_parent_default(v);
}
return unit_propagate();
}
@ -471,13 +458,15 @@ namespace array {
bool prop = false;
for (unsigned i = roots.size(); i-- > 0; ) {
theory_var v1 = roots[i];
euf::enode* n1 = var2enode(v1);
expr* e1 = var2expr(v1);
for (unsigned j = i; j-- > 0; ) {
theory_var v2 = roots[j];
euf::enode* n2 = var2enode(v2);
if (m.get_sort(n1->get_expr()) != m.get_sort(n2->get_expr()))
expr* e2 = var2expr(v2);
if (m.get_sort(e1) != m.get_sort(e2))
continue;
expr_ref eq(m.mk_eq(n1->get_expr(), n2->get_expr()), m);
if (have_different_model_values(v1, v2))
continue;
expr_ref eq(m.mk_eq(e1, e2), m);
sat::literal lit = b_internalize(eq);
if (s().value(lit) == l_undef)
prop = true;
@ -498,15 +487,10 @@ namespace array {
if (r->is_marked1()) {
continue;
}
// arrays used as indices in other arrays have to be treated as shared.
// issue #3532, #3529
//
if (ctx.is_shared(r) || is_select_arg(r)) {
TRACE("array", tout << "new shared var: #" << r->get_expr_id() << "\n";);
theory_var r_th_var = r->get_th_var(get_id());
SASSERT(r_th_var != euf::null_theory_var);
roots.push_back(r_th_var);
}
// arrays used as indices in other arrays have to be treated as shared issue #3532, #3529
if (ctx.is_shared(r) || is_select_arg(r))
roots.push_back(r->get_th_var(get_id()));
r->mark1();
to_unmark.push_back(r);
}
@ -516,6 +500,7 @@ namespace array {
}
bool solver::is_select_arg(euf::enode* r) {
SASSERT(r->is_root());
for (euf::enode* n : euf::enode_parents(r))
if (a.is_select(n->get_expr()))
for (unsigned i = 1; i < n->num_args(); ++i)