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enhance ackermannize for constant arguments

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2019-09-07 16:36:05 +03:00
parent 18ba14cff8
commit 228d68f165
7 changed files with 86 additions and 59 deletions
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4
src/ackermannization/ackermannize_bv_tactic.cpp
View file

@ -25,7 +25,9 @@ class ackermannize_bv_tactic : public tactic {
public:
ackermannize_bv_tactic(ast_manager& m, params_ref const& p)
: m(m), m_p(p)
{}
{
updt_params(p);
}
~ackermannize_bv_tactic() override { }

24
src/ackermannization/ackr_bound_probe.cpp
View file

@ -53,29 +53,9 @@ class ackr_bound_probe : public probe {
void operator()(quantifier *) {}
void operator()(var *) {}
void operator()(app * a) {
if (a->get_num_args() == 0) return;
void operator()(app * a) {
m_ackr_helper.mark_non_select(a, m_non_select);
app_set* ts = nullptr;
if (m_ackr_helper.is_select(a)) {
app* sel = to_app(a->get_arg(0));
if (!m_sel2terms.find(sel, ts)) {
ts = alloc(app_set);
m_sel2terms.insert(sel, ts);
}
}
else if (m_ackr_helper.is_uninterp_fn(a)) {
func_decl* const fd = a->get_decl();
if (!m_fun2terms.find(fd, ts)) {
ts = alloc(app_set);
m_fun2terms.insert(fd, ts);
}
}
else {
return;
}
ts->insert(a);
m_ackr_helper.insert(m_fun2terms, m_sel2terms, a);
}
};

6
src/ackermannization/ackr_helper.cpp
View file

@ -19,10 +19,12 @@
double ackr_helper::calculate_lemma_bound(fun2terms_map const& occs1, sel2terms_map const& occs2) {
double total = 0;
for (auto const& kv : occs1) {
total += n_choose_2_chk(kv.m_value->size());
total += n_choose_2_chk(kv.m_value->var_args.size());
total += kv.m_value->const_args.size() * kv.m_value->var_args.size();
}
for (auto const& kv : occs2) {
total += n_choose_2_chk(kv.m_value->size());
total += n_choose_2_chk(kv.m_value->var_args.size());
total += kv.m_value->const_args.size() * kv.m_value->var_args.size();
}
return total;
}

45
src/ackermannization/ackr_helper.h
View file

@ -22,9 +22,13 @@
class ackr_helper {
public:
typedef obj_hashtable<app> app_set;
struct app_occ {
obj_hashtable<app> const_args;
obj_hashtable<app> var_args;
};
typedef app_occ app_set;
typedef obj_map<func_decl, app_set*> fun2terms_map;
typedef obj_map<app, app_set*> sel2terms_map;
typedef obj_map<app, app_set*> sel2terms_map;
ackr_helper(ast_manager& m) : m_bvutil(m), m_autil(m) {}
@ -88,13 +92,48 @@ public:
static double calculate_lemma_bound(fun2terms_map const& occs1, sel2terms_map const& occs2);
/** \brief Calculate n choose 2. **/
inline static unsigned n_choose_2(unsigned n) { return n & 1 ? (n * (n >> 1)) : (n >> 1) * (n - 1); }
inline static unsigned n_choose_2(unsigned n) { return (n & 1) ? (n * (n >> 1)) : (n >> 1) * (n - 1); }
/** \brief Calculate n choose 2 guarded for overflow. Returns infinity if unsafe. **/
inline static double n_choose_2_chk(unsigned n) {
SASSERT(std::numeric_limits<unsigned>().max() & 32);
return n & (1 << 16) ? std::numeric_limits<double>().infinity() : n_choose_2(n);
}
void insert(fun2terms_map& f2t, sel2terms_map& s2t, app* a) {
if (a->get_num_args() == 0) return;
ast_manager& m = m_bvutil.get_manager();
app_set* ts = nullptr;
bool is_const_args = true;
if (is_select(a)) {
app* sel = to_app(a->get_arg(0));
if (!s2t.find(sel, ts)) {
ts = alloc(app_set);
s2t.insert(sel, ts);
}
}
else if (is_uninterp_fn(a)) {
func_decl* const fd = a->get_decl();
if (!f2t.find(fd, ts)) {
ts = alloc(app_set);
f2t.insert(fd, ts);
}
is_const_args = m.is_value(a->get_arg(0));
}
else {
return;
}
for (unsigned i = 1; is_const_args && i < a->get_num_args(); ++i) {
is_const_args &= m.is_value(a->get_arg(i));
}
if (is_const_args) {
ts->const_args.insert(a);
}
else {
ts->var_args.insert(a);
}
}
private:
bv_util m_bvutil;

60
src/ackermannization/lackr.cpp
View file

@ -153,10 +153,10 @@ void lackr::eager_enc() {
}
void lackr::ackr(app_set const* ts) {
const app_set::iterator r = ts->end();
for (app_set::iterator j = ts->begin(); j != r; ++j) {
auto r = ts->var_args.end();
for (auto j = ts->var_args.begin(); j != r; ++j) {
app * const t1 = *j;
app_set::iterator k = j;
auto k = j;
++k;
for (; k != r; ++k) {
app * const t2 = *k;
@ -164,27 +164,46 @@ void lackr::ackr(app_set const* ts) {
ackr(t1, t2);
}
}
for (app* t2 : ts->const_args) {
ackr(t1, t2);
}
}
}
void lackr::abstract() {
for (auto const& kv : m_fun2terms) {
void lackr::abstract_fun(fun2terms_map const& apps) {
for (auto const& kv : apps) {
func_decl* fd = kv.m_key;
for (app * t : *kv.m_value) {
for (app * t : kv.m_value->var_args) {
app * fc = m.mk_fresh_const(fd->get_name(), m.get_sort(t));
SASSERT(t->get_decl() == fd);
m_info->set_abstr(t, fc);
}
for (app * t : kv.m_value->const_args) {
app * fc = m.mk_fresh_const(fd->get_name(), m.get_sort(t));
SASSERT(t->get_decl() == fd);
m_info->set_abstr(t, fc);
}
}
for (auto& kv : m_sel2terms) {
}
void lackr::abstract_sel(sel2terms_map const& apps) {
for (auto const& kv : apps) {
func_decl * fd = kv.m_key->get_decl();
for (app * t : *kv.m_value) {
for (app * t : kv.m_value->const_args) {
app * fc = m.mk_fresh_const(fd->get_name(), m.get_sort(t));
m_info->set_abstr(t, fc);
}
for (app * t : kv.m_value->var_args) {
app * fc = m.mk_fresh_const(fd->get_name(), m.get_sort(t));
m_info->set_abstr(t, fc);
}
}
}
void lackr::abstract() {
abstract_fun(m_fun2terms);
abstract_sel(m_sel2terms);
m_info->seal();
// perform abstraction of the formulas
for (expr * f : m_formulas) {
@ -194,28 +213,7 @@ void lackr::abstract() {
}
void lackr::add_term(app* a) {
app_set* ts = nullptr;
if (a->get_num_args() == 0)
return;
if (m_ackr_helper.is_select(a)) {
app* sel = to_app(a->get_arg(0));
if (!m_sel2terms.find(sel, ts)) {
ts = alloc(app_set);
m_sel2terms.insert(sel, ts);
}
}
else if (m_ackr_helper.is_uninterp_fn(a)) {
func_decl* const fd = a->get_decl();
if (!m_fun2terms.find(fd, ts)) {
ts = alloc(app_set);
m_fun2terms.insert(fd, ts);
}
}
else {
return;
}
TRACE("ackermannize", tout << "term(" << mk_ismt2_pp(a, m, 2) << ")\n";);
ts->insert(a);
m_ackr_helper.insert(m_fun2terms, m_sel2terms, a);
}
void lackr::push_abstraction() {

4
src/ackermannization/lackr.h
View file

@ -123,5 +123,9 @@ class lackr {
// Collect all uninterpreted terms, skipping 0-arity.
//
bool collect_terms();
void abstract_sel(sel2terms_map const& apps);
void abstract_fun(fun2terms_map const& apps);
};
#endif /* LACKR_H_ */

2
src/opt/opt_context.cpp
View file

@ -38,6 +38,7 @@ Notes:
#include "tactic/arith/eq2bv_tactic.h"
#include "tactic/bv/dt2bv_tactic.h"
#include "tactic/generic_model_converter.h"
#include "ackermannization/ackermannize_bv_tactic.h"
#include "sat/sat_solver/inc_sat_solver.h"
#include "qe/qsat.h"
#include "opt/opt_context.h"
@ -804,6 +805,7 @@ namespace opt {
and_then(mk_simplify_tactic(m, m_params),
mk_propagate_values_tactic(m),
mk_solve_eqs_tactic(m),
mk_ackermannize_bv_tactic(m, m_params),
// NB: mk_elim_uncstr_tactic(m) is not sound with soft constraints
mk_simplify_tactic(m));
opt_params optp(m_params);