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updates to mbqi

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

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2018-05-17 13:06:47 -07:00 • committed by Arie Gurfinkel
parent 80c39eb037
commit 20300bbf94
3 changed files with 237 additions and 62 deletions
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62
src/muz/spacer/spacer_util.cpp
View file

@ -90,33 +90,33 @@ namespace spacer {
if (!m_model) { return; }
m_mev = alloc(model_evaluator, *m_model);
}
bool model_evaluator_util::eval(expr *e, expr_ref &result, bool model_completion) {
m_mev->set_model_completion (model_completion);
try {
m_mev->operator() (e, result);
return true;
}
}
catch (model_evaluator_exception &ex) {
(void)ex;
TRACE("spacer_model_evaluator", tout << ex.msg () << "\n";);
return false;
}
}
bool model_evaluator_util::eval(const expr_ref_vector &v,
expr_ref& res, bool model_completion) {
expr_ref e(m);
e = mk_and (v);
return eval(e, res, model_completion);
}
bool model_evaluator_util::is_true(const expr_ref_vector &v) {
expr_ref res(m);
return eval (v, res, false) && m.is_true (res);
}
bool model_evaluator_util::is_false(expr *x) {
expr_ref res(m);
return eval(x, res, false) && m.is_false (res);
@ -126,7 +126,7 @@ namespace spacer {
expr_ref res(m);
return eval(x, res, false) && m.is_true (res);
}
void reduce_disequalities(model& model, unsigned threshold, expr_ref& fml) {
ast_manager& m = fml.get_manager();
expr_ref_vector conjs(m);
@ -172,16 +172,16 @@ namespace spacer {
SASSERT(orig_size <= 1 + conjs.size());
if (i + 1 == orig_size) {
// no-op.
}
}
else if (orig_size <= conjs.size()) {
// no-op
}
}
else {
SASSERT(orig_size == 1 + conjs.size());
--orig_size;
--i;
}
}
}
else {
conjs[i] = tmp;
}
@ -199,7 +199,7 @@ namespace spacer {
ast_manager& m;
public:
ite_hoister(ast_manager& m): m(m) {}
br_status mk_app_core(func_decl* f, unsigned num_args, expr* const* args, expr_ref& result) {
if (m.is_ite(f)) {
return BR_FAILED;
@ -234,7 +234,7 @@ namespace spacer {
}
ite_hoister_cfg(ast_manager & m, params_ref const & p):m_r(m) {}
};
class ite_hoister_star : public rewriter_tpl<ite_hoister_cfg> {
ite_hoister_cfg m_cfg;
public:
@ -242,7 +242,7 @@ namespace spacer {
rewriter_tpl<ite_hoister_cfg>(m, false, m_cfg),
m_cfg(m, p) {}
};
void hoist_non_bool_if(expr_ref& fml) {
ast_manager& m = fml.get_manager();
scoped_no_proof _sp(m);
@ -274,7 +274,7 @@ namespace spacer {
bool is_arith_expr(expr *e) const {
return is_app(e) && a.get_family_id() == to_app(e)->get_family_id();
}
bool is_offset(expr* e) const {
if (a.is_numeral(e)) {
return true;
@ -358,7 +358,7 @@ namespace spacer {
!a.is_mul(lhs) &&
!a.is_mul(rhs);
}
bool test_term(expr* e) const {
if (m.is_bool(e)) {
return true;
@ -403,9 +403,9 @@ namespace spacer {
public:
test_diff_logic(ast_manager& m): m(m), a(m), bv(m), m_is_dl(true), m_test_for_utvpi(false) {}
void test_for_utvpi() { m_test_for_utvpi = true; }
void operator()(expr* e) {
if (!m_is_dl) {
return;
@ -422,7 +422,7 @@ namespace spacer {
m_is_dl = test_term(a->get_arg(i));
}
}
if (!m_is_dl) {
char const* msg = "non-diff: ";
if (m_test_for_utvpi) {
@ -431,10 +431,10 @@ namespace spacer {
IF_VERBOSE(1, verbose_stream() << msg << mk_pp(e, m) << "\n";);
}
}
bool is_dl() const { return m_is_dl; }
};
bool is_difference_logic(ast_manager& m, unsigned num_fmls, expr* const* fmls) {
test_diff_logic test(m);
expr_fast_mark1 mark;
@ -443,7 +443,7 @@ namespace spacer {
}
return test.is_dl();
}
bool is_utvpi_logic(ast_manager& m, unsigned num_fmls, expr* const* fmls) {
test_diff_logic test(m);
test.test_for_utvpi();
@ -455,7 +455,7 @@ namespace spacer {
}
void subst_vars(ast_manager& m,
void subst_vars(ast_manager& m,
app_ref_vector const& vars,
model* M, expr_ref& fml) {
expr_safe_replace sub (m);
@ -506,7 +506,7 @@ void to_mbp_benchmark(std::ostream &out, expr* fml, const app_ref_vector &vars)
flatten_and (fml, flat);
fml = mk_and(flat);
}
// uncomment for benchmarks
//to_mbp_benchmark(verbose_stream(), fml, vars);
@ -523,7 +523,7 @@ void to_mbp_benchmark(std::ostream &out, expr* fml, const app_ref_vector &vars)
qe_lite qe(m, p, false);
qe (vars, fml);
rw (fml);
TRACE ("spacer_mbp",
tout << "After qe_lite:\n";
tout << mk_pp (fml, m) << "\n";
@ -531,7 +531,7 @@ void to_mbp_benchmark(std::ostream &out, expr* fml, const app_ref_vector &vars)
SASSERT (!m.is_false (fml));
// sort out vars into bools, arith (int/real), and arrays
for (app* v : vars) {
if (m.is_bool (v)) {
@ -545,7 +545,7 @@ void to_mbp_benchmark(std::ostream &out, expr* fml, const app_ref_vector &vars)
arith_vars.push_back (v);
}
}
// substitute Booleans
if (!bool_sub.empty()) {
bool_sub (fml);
@ -555,13 +555,13 @@ void to_mbp_benchmark(std::ostream &out, expr* fml, const app_ref_vector &vars)
TRACE ("spacer_mbp", tout << "Projected Booleans:\n" << fml << "\n"; );
bool_sub.reset ();
}
TRACE ("spacer_mbp",
tout << "Array vars:\n";
tout << array_vars;);
vars.reset ();
// project arrays
{
scoped_no_proof _sp (m);
@ -572,14 +572,14 @@ void to_mbp_benchmark(std::ostream &out, expr* fml, const app_ref_vector &vars)
srw (fml);
SASSERT (!m.is_false (fml));
}
TRACE ("spacer_mbp",
tout << "extended model:\n";
model_pp (tout, *M);
tout << "Auxiliary variables of index and value sorts:\n";
tout << vars;
);
if (vars.empty()) { break; }
}

181
src/qe/qe_arrays.cpp
View file

@ -157,8 +157,8 @@ namespace qe {
static bool is_eq(expr_ref_vector const& xs, expr_ref_vector const& ys) {
for (unsigned i = 0; i < xs.size(); ++i) if (xs[i] != ys[i]) return false;
return true;
}
return true;
}
static bool is_eq(vector<rational> const& xs, vector<rational> const& ys) {
for (unsigned i = 0; i < xs.size(); ++i) if (xs[i] != ys[i]) return false;
@ -984,9 +984,9 @@ namespace qe {
TRACE("qe", tout << "non-arithmetic index sort for Ackerman" << mk_pp(srt, m) << "\n";);
// TBD: generalize to also bit-vectors.
is_numeric = false;
}
}
}
unsigned start = m_idxs.size (); // append at the end
for (app * a : sel_terms) {
expr_ref_vector idxs(m, arity, a->get_args() + 1);
@ -1018,13 +1018,13 @@ namespace qe {
}
if (is_numeric) {
// sort reprs by their value and add a chain of strict inequalities
compare_idx cmp(*this);
std::sort(m_idxs.begin() + start, m_idxs.end(), cmp);
// sort reprs by their value and add a chain of strict inequalities
compare_idx cmp(*this);
std::sort(m_idxs.begin() + start, m_idxs.end(), cmp);
for (unsigned i = start; i + 1 < m_idxs.size(); ++i) {
m_idx_lits.push_back (mk_lex_lt(m_idxs[i].idx, m_idxs[i+1].idx));
}
m_idx_lits.push_back (mk_lex_lt(m_idxs[i].idx, m_idxs[i+1].idx));
}
}
else if (arity == 1) {
// create distinct constraint.
expr_ref_vector xs(m);
@ -1163,12 +1163,12 @@ namespace qe {
return BR_DONE;
}
return BR_FAILED;
}
}
lbool compare(expr* x, expr* y) {
NOT_IMPLEMENTED_YET();
return l_undef;
}
}
};
struct indices {
@ -1181,10 +1181,10 @@ namespace qe {
for (unsigned i = 0; i < n; ++i) {
VERIFY(model.eval(vars[i], val));
m_values.push_back(val);
}
}
}
};
ast_manager& m;
array_util a;
scoped_ptr<contains_app> m_var;
@ -1194,6 +1194,67 @@ namespace qe {
bool solve(model& model, app_ref_vector& vars, expr_ref_vector& lits) {
return false;
}
bool operator()(model& model, app* var, app_ref_vector& vars, expr_ref_vector& lits) {
TRACE("qe", tout << mk_pp(var, m) << "\n" << lits;);
m_var = alloc(contains_app, m, var);
// reduce select-store redeces based on model.
// rw_cfg rw(m);
// rw(lits);
// try first to solve for var.
if (solve_eq(model, vars, lits)) {
return true;
}
app_ref_vector selects(m);
// check that only non-select occurrences are in disequalities.
if (!check_diseqs(lits, selects)) {
TRACE("qe", tout << "Could not project " << mk_pp(var, m) << " for:\n" << lits << "\n";);
return false;
}
// remove disequalities.
elim_diseqs(lits);
// Ackerman reduction on remaining select occurrences
// either replace occurrences by model value or other node
// that is congruent to model value.
ackermanize_select(model, selects, vars, lits);
TRACE("qe", tout << selects << "\n" << lits << "\n";);
return true;
}
void ackermanize_select(model& model, app_ref_vector const& selects, app_ref_vector& vars, expr_ref_vector& lits) {
expr_ref_vector vals(m), reps(m);
expr_ref val(m);
expr_safe_replace sub(m);
if (selects.empty()) {
return;
}
app_ref sel(m);
for (unsigned i = 0; i < selects.size(); ++i) {
sel = m.mk_fresh_const("sel", m.get_sort(selects[i]));
VERIFY (model.eval(selects[i], val));
model.register_decl(sel->get_decl(), val);
vals.push_back(to_app(val));
reps.push_back(val); // TODO: direct pass could handle nested selects.
vars.push_back(sel);
sub.insert(selects[i], val);
}
sub(lits);
remove_true(lits);
project_plugin::partition_args(model, selects, lits);
project_plugin::partition_values(model, reps, lits);
}
void remove_true(expr_ref_vector& lits) {
@ -1216,6 +1277,80 @@ namespace qe {
}
}
// check that x occurs only under selects or in disequalities.
bool check_diseqs(expr_ref_vector const& lits, app_ref_vector& selects) {
expr_mark mark;
ptr_vector<app> todo;
app* e;
for (unsigned i = 0; i < lits.size(); ++i) {
e = to_app(lits[i]);
if (is_diseq_x(e)) {
continue;
}
if (contains_x(e)) {
todo.push_back(e);
}
}
while (!todo.empty()) {
e = todo.back();
todo.pop_back();
if (mark.is_marked(e)) {
continue;
}
mark.mark(e);
if (m_var->x() == e) {
return false;
}
unsigned start = 0;
if (a.is_select(e)) {
if (e->get_arg(0) == m_var->x()) {
start = 1;
selects.push_back(e);
}
}
for (unsigned i = start; i < e->get_num_args(); ++i) {
todo.push_back(to_app(e->get_arg(i)));
}
}
return true;
}
void elim_diseqs(expr_ref_vector& lits) {
for (unsigned i = 0; i < lits.size(); ++i) {
if (is_diseq_x(lits[i].get())) {
project_plugin::erase(lits, i);
}
}
}
bool is_update_x(app* e) {
do {
if (m_var->x() == e) {
return true;
}
if (a.is_store(e) && contains_x(e->get_arg(0))) {
for (unsigned i = 1; i < e->get_num_args(); ++i) {
if (contains_x(e->get_arg(i))) {
return false;
}
}
e = to_app(e->get_arg(0));
continue;
}
}
while (false);
return false;
}
bool is_diseq_x(expr* e) {
expr *f, * s, *t;
if (m.is_not(e, f) && m.is_eq(f, s, t)) {
if (contains_x(s) && !contains_x(t) && is_update_x(to_app(s))) return true;
if (contains_x(t) && !contains_x(s) && is_update_x(to_app(t))) return true;
}
return false;
}
bool solve_eq(model& model, app_ref_vector& vars, expr_ref_vector& lits) {
// find an equality to solve for.
expr* s, *t;
@ -1367,13 +1502,7 @@ namespace qe {
}
bool array_project_plugin::operator()(model& model, app* var, app_ref_vector& vars, expr_ref_vector& lits) {
ast_manager& m = vars.get_manager();
app_ref_vector vvars(m, 1, &var);
expr_ref fml = mk_and(lits);
(*this)(model, vvars, fml, vars, false);
lits.reset();
flatten_and(fml, lits);
return true;
return (*m_imp)(model, var, vars, lits);
}
bool array_project_plugin::solve(model& model, app_ref_vector& vars, expr_ref_vector& lits) {
@ -1390,11 +1519,11 @@ namespace qe {
array_project_eqs_util pe (m);
pe (mdl, arr_vars, fml, aux_vars);
TRACE ("qe",
tout << "Projected array eqs: " << fml << "\n";
tout << "Remaining array vars: " << arr_vars << "\n";
tout << "Aux vars: " << aux_vars << "\n";
tout << "Projected array eqs:\n" << fml << "\n";
tout << "Remaining array vars:\n" << arr_vars;
tout << "Aux vars:\n" << aux_vars;
);
// 2. reduce selects
array_select_reducer rs (m);
rs (mdl, arr_vars, fml, reduce_all_selects);
@ -1406,8 +1535,8 @@ namespace qe {
ps (mdl, arr_vars, fml, aux_vars);
TRACE ("qe",
tout << "Projected array selects: " << fml << "\n";
tout << "All aux vars: " << aux_vars << "\n";
tout << "Projected array selects:\n" << fml << "\n";
tout << "All aux vars:\n" << aux_vars;
);
}

56
src/qe/qe_mbp.cpp
View file

@ -77,6 +77,40 @@ expr_ref project_plugin::pick_equality(ast_manager& m, model& model, expr* t) {
return expr_ref(nullptr, m);
}
void project_plugin::partition_values(model& model, expr_ref_vector const& vals, expr_ref_vector& lits) {
ast_manager& m = vals.get_manager();
expr_ref val(m);
expr_ref_vector trail(m), reps(m);
obj_map<expr, expr*> roots;
for (unsigned i = 0; i < vals.size(); ++i) {
expr* v = vals[i], *root;
VERIFY (model.eval(v, val));
if (roots.find(val, root)) {
lits.push_back(m.mk_eq(v, root));
}
else {
roots.insert(val, v);
trail.push_back(val);
reps.push_back(v);
}
}
if (reps.size() > 1) {
lits.push_back(mk_distinct(reps));
}
}
void project_plugin::partition_args(model& model, app_ref_vector const& selects, expr_ref_vector& lits) {
ast_manager& m = selects.get_manager();
if (selects.empty()) return;
unsigned num_args = selects[0]->get_decl()->get_arity();
for (unsigned j = 1; j < num_args; ++j) {
expr_ref_vector args(m);
for (unsigned i = 0; i < selects.size(); ++i) {
args.push_back(selects[i]->get_arg(j));
}
project_plugin::partition_values(model, args, lits);
}
}
void project_plugin::erase(expr_ref_vector& lits, unsigned& i) {
lits[i] = lits.back();
@ -100,6 +134,7 @@ class mbp::impl {
// parameters
bool m_reduce_all_selects;
bool m_native_mbp;
bool m_dont_sub;
void add_plugin(project_plugin* p) {
@ -287,7 +322,8 @@ class mbp::impl {
void operator() (app *n) {
expr *e1, *e2;
if (m_array.is_select (n)) {
for (expr * arg : *n) {
for (unsigned i = 1; i < n->get_num_args(); ++i) {
expr * arg = n->get_arg(i);
if (m.get_sort(arg) == m.get_sort(m_var) && arg != m_var)
m_res.push_back (arg);
}
@ -340,7 +376,8 @@ class mbp::impl {
// -- evaluate to initialize eval cache
(void) eval (fml);
unsigned j = 0;
for (app * v : vars) {
for (unsigned i = 0; i < vars.size (); ++i) {
app* v = vars.get(i);
if (!project_var (eval, v, fml)) {
vars[j++] = v;
}
@ -350,6 +387,7 @@ class mbp::impl {
public:
opt::inf_eps maximize(expr_ref_vector const& fmls, model& mdl, app* t, expr_ref& ge, expr_ref& gt) {
arith_project_plugin arith(m);
return arith.maximize(fmls, mdl, t, ge, gt);
@ -490,6 +528,7 @@ public:
void updt_params(params_ref const& p) {
m_params.append(p);
m_reduce_all_selects = m_params.get_bool("reduce_all_selects", false);
m_native_mbp = m_params.get_bool("native_mbp", false);
m_dont_sub = m_params.get_bool("dont_sub", false);
}
@ -508,7 +547,6 @@ public:
bool validate_model(model& model, expr_ref_vector const& fmls) {
expr_ref val(m);
model_evaluator eval(model);
for (expr * f : fmls) {
VERIFY(model.eval(f, val) && m.is_true(val));
}
@ -637,19 +675,26 @@ public:
tout << "extended model:\n";
model_pp (tout, mdl);
tout << "Auxiliary variables of index and value sorts:\n";
tout << vars << "\n";
tout << vars;
);
}
// project reals and ints
if (!arith_vars.empty ()) {
TRACE ("qe", tout << "Arith vars: " << arith_vars << "\n";);
TRACE ("qe", tout << "Arith vars:\n" << arith_vars;);
if (m_native_mbp) {
expr_ref_vector fmls(m);
flatten_and (fml, fmls);
(*this)(true, arith_vars, mdl, fmls);
fml = mk_and (fmls);
SASSERT (arith_vars.empty ());
}
else {
NOT_IMPLEMENTED_YET();
// qe::arith_project (mdl, arith_vars, fml);
}
TRACE ("qe",
tout << "Projected arith vars:\n" << fml << "\n";
@ -693,6 +738,7 @@ void mbp::updt_params(params_ref const& p) {
void mbp::get_param_descrs(param_descrs & r) {
r.insert("reduce_all_selects", CPK_BOOL, "(default: false) reduce selects");
r.insert("native_mbp", CPK_BOOL, "(default: false) switch between native and spacer tailored mbp");
r.insert("dont_sub", CPK_BOOL, "(default: false) disable substitution of values for free variables");
}