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base working mbi

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2020-01-13 15:45:06 -08:00
parent 77689ed002
commit 453ef631a0
10 changed files with 234 additions and 140 deletions

View file

@ -325,6 +325,7 @@ namespace qe {
}
}
fmls.shrink(j);
TRACE("qe", tout << "formulas\n" << fmls << "\n";);
// fmls holds residue,
// mbo holds linear inequalities that are in scope
@ -380,7 +381,11 @@ namespace qe {
}
mbo.display(tout););
vector<opt::model_based_opt::def> defs = mbo.project(real_vars.size(), real_vars.c_ptr(), compute_def);
TRACE("qe", mbo.display(tout););
TRACE("qe", mbo.display(tout << "mbo result\n");
for (auto const& d : defs) {
tout << "def: " << d << "\n";
}
);
vector<row> rows;
mbo.get_live_rows(rows);

View file

@ -1442,13 +1442,13 @@ namespace qe {
for_each_store_proc(imp& i, term_graph& tg) : m_imp(i), tg(tg) {}
void operator()(app* n) {
if (m_imp.a.is_array(n) && tg.get_model_based_rep(n)) {
if (m_imp.a.is_array(n) && tg.rep_of(n)) {
m_imp.add_array(n);
}
if (m_imp.a.is_store(n) &&
(tg.get_model_based_rep(n->get_arg(0)) ||
tg.get_model_based_rep(n->get_arg(n->get_num_args() - 1)))) {
(tg.rep_of(n->get_arg(0)) ||
tg.rep_of(n->get_arg(n->get_num_args() - 1)))) {
m_imp.m_stores.push_back(n);
for (unsigned i = 1; i + 1 < n->get_num_args(); ++i) {
m_imp.add_index_sort(n->get_arg(i));
@ -1466,7 +1466,7 @@ namespace qe {
void operator()(app* n) {
auto* v = m_imp.is_index(n);
if (v && tg.get_model_based_rep(n)) {
if (v && tg.rep_of(n)) {
v->push_back(n);
}
}

View file

@ -117,7 +117,8 @@ namespace qe {
}
void prop_mbi_plugin::block(expr_ref_vector const& lits) {
m_solver->assert_expr(mk_not(mk_and(lits)));
expr_ref clause(mk_not(mk_and(lits)), m);
m_solver->assert_expr(clause);
}
// -------------------------------
@ -171,6 +172,7 @@ namespace qe {
bool uflia_mbi::get_literals(model_ref& mdl, expr_ref_vector& lits) {
lits.reset();
IF_VERBOSE(10, verbose_stream() << "atoms: " << m_atoms << "\n");
for (expr* e : m_atoms) {
if (mdl->is_true(e)) {
lits.push_back(e);
@ -204,7 +206,7 @@ namespace qe {
*
* The result is ordered using deepest term first.
*/
app_ref_vector uflia_mbi::get_arith_vars(expr_ref_vector& lits) {
app_ref_vector uflia_mbi::get_arith_vars(expr_ref_vector const& lits) {
app_ref_vector avars(m);
svector<bool> seen;
arith_util a(m);
@ -221,7 +223,7 @@ namespace qe {
}
}
order_avars(avars);
TRACE("qe", tout << "vars: " << avars << "\n";);
TRACE("qe", tout << "vars: " << avars << " from " << lits << "\n";);
return avars;
}
@ -263,14 +265,57 @@ namespace qe {
*/
void uflia_mbi::project(model_ref& mdl, expr_ref_vector& lits) {
TRACE("qe",
tout << lits << "\n" << *mdl << "\n";
tout << "project literals: " << lits << "\n" << *mdl << "\n";
tout << m_solver->get_assertions() << "\n";);
add_dcert(mdl, lits);
expr_ref_vector alits(m), uflits(m);
split_arith(lits, alits, uflits);
auto avars = get_arith_vars(lits);
auto defs = arith_project(mdl, avars, lits);
substitute(defs, lits);
project_euf(mdl, lits);
vector<def> defs = arith_project(mdl, avars, alits);
prune_defs(defs);
substitute(defs, uflits);
project_euf(mdl, uflits);
lits.reset();
lits.append(alits);
lits.append(uflits);
IF_VERBOSE(10, verbose_stream() << "projection : " << lits << "\n");
}
void uflia_mbi::split_arith(expr_ref_vector const& lits,
expr_ref_vector& alits,
expr_ref_vector& uflits) {
arith_util a(m);
for (expr* lit : lits) {
expr* atom = lit, *x = nullptr, *y = nullptr;
m.is_not(lit, atom);
if (m.is_eq(atom, x, y)) {
if (a.is_int_real(x)) {
alits.push_back(lit);
}
uflits.push_back(lit);
}
else if (a.is_arith_expr(atom)) {
alits.push_back(lit);
}
else {
uflits.push_back(lit);
}
}
}
/**
* prune defs to only contain substitutions of terms with leading uninterpreted function.
*/
void uflia_mbi::prune_defs(vector<def>& defs) {
unsigned i = 0;
for (auto& d : defs) {
if (!is_shared(to_app(d.var)->get_decl())) {
defs[i++] = d;
}
}
defs.shrink(i);
}
/**
@ -284,8 +329,7 @@ namespace qe {
term_graph tg(m);
func_decl_ref_vector shared(m_shared_trail);
tg.set_vars(shared, false);
tg.add_lits(lits);
lits.append(tg.get_ackerman_disequalities());
lits.append(tg.dcert(*mdl.get(), lits));
TRACE("qe", tout << "project: " << lits << "\n";);
}
@ -293,13 +337,14 @@ namespace qe {
* \brief substitute solution to arithmetical variables into lits
*/
void uflia_mbi::substitute(vector<def> const& defs, expr_ref_vector& lits) {
TRACE("qe", tout << "start substitute: " << lits << "\n";);
for (auto const& def : defs) {
expr_safe_replace rep(m);
rep.insert(def.var, def.term);
rep(lits);
TRACE("qe", tout << "substitute: " << def.var << " |-> " << def.term << ": " << lits << "\n";);
}
TRACE("qe", tout << "substitute: " << lits << "\n";);
IF_VERBOSE(1, verbose_stream() << lits << "\n");
IF_VERBOSE(1, verbose_stream() << "substituted: " << lits << "\n");
}
/**
@ -333,10 +378,11 @@ namespace qe {
}
void uflia_mbi::block(expr_ref_vector const& lits) {
// want to rely only on atoms from original literals: collect_atoms(lits);
expr_ref conj(mk_not(mk_and(lits)), m);
expr_ref clause(mk_not(mk_and(lits)), m);
collect_atoms(lits);
m_fmls.push_back(clause);
TRACE("qe", tout << "block " << lits << "\n";);
m_solver->assert_expr(conj);
m_solver->assert_expr(clause);
}

View file

@ -120,10 +120,14 @@ namespace qe {
void order_avars(app_ref_vector& avars);
void add_dcert(model_ref& mdl, expr_ref_vector& lits);
app_ref_vector get_arith_vars(expr_ref_vector& lits);
app_ref_vector get_arith_vars(expr_ref_vector const& lits);
vector<def> arith_project(model_ref& mdl, app_ref_vector& avars, expr_ref_vector& lits);
void substitute(vector<def> const& defs, expr_ref_vector& lits);
void project_euf(model_ref& mdl, expr_ref_vector& lits);
void split_arith(expr_ref_vector const& lits,
expr_ref_vector& alits,
expr_ref_vector& uflits);
void prune_defs(vector<def>& defs);
public:
uflia_mbi(solver* s, solver* emptySolver);
~uflia_mbi() override {}

View file

@ -19,6 +19,7 @@ Notes:
#include "util/util.h"
#include "util/uint_set.h"
#include "util/obj_pair_hashtable.h"
#include "ast/ast_pp.h"
#include "ast/ast_util.h"
#include "ast/for_each_expr.h"
@ -217,7 +218,7 @@ namespace qe {
bool term_graph::is_variable_proc::operator()(const expr * e) const {
if (!is_app(e)) return false;
const app *a = ::to_app(e);
TRACE("qe", tout << a->get_family_id() << " " << m_solved.contains(a->get_decl()) << " " << m_decls.contains(a->get_decl()) << "\n";);
TRACE("qe_verbose", tout << a->get_family_id() << " " << m_solved.contains(a->get_decl()) << " " << m_decls.contains(a->get_decl()) << "\n";);
return
a->get_family_id() == null_family_id &&
!m_solved.contains(a->get_decl()) &&
@ -1176,56 +1177,95 @@ namespace qe {
}
expr* term_graph::get_model_based_rep(expr* e) {
expr* term_graph::rep_of(expr* e) {
SASSERT(m_projector);
term* t = get_term(e);
SASSERT(t && "only get representatives");
return m_projector->find_term2app(*t);
}
expr_ref_vector term_graph::dcert(model& mdl, expr_ref_vector const& lits) {
#if 0
obj_pair_hashtable<expr, expr> diseqs;
extract_disequalities(lits, diseqs);
svector<std::pair<expr*, expr*>> todo;
for (auto const& p : diseqs) todo.push_back(p);
expr_ref_vector result(m);
TRACE("qe", tout << "dcert " << lits << "\n";);
struct pair_t {
expr* a, *b;
pair_t(): a(nullptr), b(nullptr) {}
pair_t(expr* _a, expr* _b):a(_a), b(_b) {
if (a->get_id() > b->get_id()) std::swap(a, b);
}
struct hash {
unsigned operator()(pair_t const& p) const { return mk_mix(p.a ? p.a->hash() : 0, p.b ? p.b->hash() : 0, 1); }
};
struct eq {
bool operator()(pair_t const& a, pair_t const& b) const { return a.a == b.a && a.b == b.b; }
};
};
hashtable<pair_t, pair_t::hash, pair_t::eq> diseqs;
expr_ref_vector result(m);
add_lits(lits);
auto const partitions = get_partition(mdl);
svector<pair_t> todo;
for (expr* e : lits) {
expr* ne, *a, *b;
if (m.is_not(e, ne) && m.is_eq(ne, a, b) && (is_uninterp(a) || is_uninterp(b))) {
todo.push_back(pair_t(a, b));
}
else if (is_uninterp(e)) {
todo.push_back(pair_t(e, m.mk_false()));
}
else if (m.is_not(e, ne) && is_uninterp(ne)) {
todo.push_back(pair_t(ne, m.mk_true()));
}
}
for (auto& p : todo) diseqs.insert(p);
obj_map<expr, unsigned> term2pid;
unsigned id = 0;
for (auto const& vec : partitions) {
for (expr* e : vec) term2pid.insert(e, id);
++id;
}
auto partition_of = [&](expr* e) { return partitions[term2pid[e]]; };
auto in_table = [&](expr* a, expr* b) {
return diseqs.contains(pair_t(a, b));
};
auto same_function = [](expr* a, expr* b) {
return is_app(a) && is_app(b) &&
to_app(a)->get_decl() == to_app(b)->get_decl() && to_app(a)->get_family_id() == null_family_id;
};
// make sure that diseqs is closed under function applications
// of uninterpreted functions.
for (unsigned idx = 0; idx < todo.size(); ++idx) {
auto p = todo[idx];
for (app* t1 : partition_of(p.first)) {
for (app* t2 : partition_of(p.second)) {
for (expr* t1 : partition_of(p.a)) {
for (expr* t2 : partition_of(p.b)) {
if (same_function(t1, t2)) {
unsigned sz = t1->get_num_args();
unsigned sz = to_app(t1)->get_num_args();
bool found = false;
std::pair<expr*, expr*> q(nullptr, nullptr);
pair_t q(t1, t2);
for (unsigned i = 0; i < sz; ++i) {
expr* arg1 = t1->get_arg(i);
expr* arg2 = t2->get_arg(i);
expr* arg1 = to_app(t1)->get_arg(i);
expr* arg2 = to_app(t2)->get_arg(i);
if (mdl(arg1) == mdl(t2)) {
continue;
}
if (in_table(diseqs, arg1, arg2)) {
if (in_table(arg1, arg2)) {
found = true;
break;
}
q = make_diseq(arg1, arg2);
q = pair_t(arg1, arg2);
}
if (!found) {
diseqs.insert(q);
todo.push_back(q);
result.push_back(m.mk_not(m.mk_eq(q.first, q.second)));
result.push_back(m.mk_not(m.mk_eq(q.a, q.b)));
}
}
}
}
}
TRACE("qe", tout << result << "\n";);
return result;
#endif
NOT_IMPLEMENTED_YET();
return expr_ref_vector(m);
}
}

View file

@ -87,7 +87,7 @@ namespace qe {
void display(std::ostream &out);
bool is_pure_def(expr* atom, expr *& v);
public:
term_graph(ast_manager &m);
~term_graph();
@ -150,7 +150,7 @@ namespace qe {
* Map expression that occurs in added literals into representative if it exists.
*/
void add_model_based_terms(model& mdl, expr_ref_vector const& terms);
expr* get_model_based_rep(expr* e);
expr* rep_of(expr* e);
};

View file

@ -336,8 +336,7 @@ namespace sat {
void aig_cuts::init_cut_set(unsigned id) {
SASSERT(m_aig[id].size() == 1);
node const& n = m_aig[id][0];
SASSERT(n.is_valid());
SASSERT(m_aig[id][0].is_valid());
auto& cut_set = m_cuts[id];
reset(cut_set);
cut_set.init(m_region, m_config.m_max_cutset_size + 1, id);

View file

@ -16,7 +16,6 @@
--*/
#include "util/union_find.h"
#include "sat/sat_aig_simplifier.h"
#include "sat/sat_xor_finder.h"
#include "sat/sat_elim_eqs.h"
@ -231,79 +230,77 @@ namespace sat {
void aig_simplifier::aig2clauses() {
vector<cut_set> const& cuts = m_aig_cuts();
m_stats.m_num_cuts = m_aig_cuts.num_cuts();
add_dont_cares(cuts);
cuts2equiv(cuts);
}
map<cut const*, unsigned, cut::hash_proc, cut::eq_proc> cut2id;
void aig_simplifier::cuts2equiv(vector<cut_set> const& cuts) {
map<cut const*, unsigned, cut::hash_proc, cut::eq_proc> cut2id;
bool new_eq = false;
union_find_default_ctx ctx;
union_find<> uf(ctx), uf2(ctx);
union_find<> uf(ctx);
for (unsigned i = 2*s.num_vars(); i--> 0; ) uf.mk_var();
auto add_eq = [&](literal l1, literal l2) {
uf.merge(l1.index(), l2.index());
uf.merge((~l1).index(), (~l2).index());
new_eq = true;
};
bool new_eq = false;
for (unsigned i = cuts.size(); i-- > 0; ) {
literal u(i, false);
for (auto& c : cuts[i]) {
unsigned j = 0;
if (m_config.m_enable_units && c.is_true()) {
if (s.value(i) == l_undef) {
literal lit(i, false);
// validate_unit(lit);
IF_VERBOSE(2, verbose_stream() << "new unit " << lit << "\n");
s.assign_unit(lit);
++m_stats.m_num_units;
}
break;
}
if (m_config.m_enable_units && c.is_false()) {
if (s.value(i) == l_undef) {
literal lit(i, true);
// validate_unit(lit);
IF_VERBOSE(2, verbose_stream() << "new unit " << lit << "\n");
s.assign_unit(lit);
++m_stats.m_num_units;
}
break;
}
if (cut2id.find(&c, j)) {
VERIFY(i != j);
literal u(i, false);
literal v(j, false);
IF_VERBOSE(10,
verbose_stream() << u << " " << c << "\n";
verbose_stream() << v << ": ";
for (cut const& d : cuts[v.var()]) verbose_stream() << d << "\n";);
certify_equivalence(u, v, c);
//validate_eq(u, v);
add_eq(u, v);
TRACE("aig_simplifier", tout << u << " == " << v << "\n";);
new_eq = true;
break;
}
cut nc(c);
nc.negate();
if (cut2id.find(&nc, j)) {
if (i == j) continue;
literal u(i, false);
literal v(j, true);
certify_equivalence(u, v, c);
// validate_eq(u, v);
add_eq(u, v);
TRACE("aig_simplifier", tout << u << " == " << v << "\n";);
new_eq = true;
break;
if (m_config.m_enable_units && c.is_true()) {
assign_unit(u);
}
else if (m_config.m_enable_units && c.is_false()) {
assign_unit(~u);
}
else if (cut2id.find(&c, j)) {
literal v(j, false);
assign_equiv(c, u, v);
add_eq(u, v);
}
else if (cut2id.find(&nc, j)) {
literal v(j, true);
assign_equiv(c, u, v);
add_eq(u, v);
}
else {
cut2id.insert(&c, i);
}
cut2id.insert(&c, i);
}
}
if (!new_eq) {
return;
if (new_eq) {
uf2equiv(uf);
}
new_eq = false;
}
void aig_simplifier::assign_unit(literal lit) {
if (s.value(lit) == l_undef) {
// validate_unit(lit);
IF_VERBOSE(2, verbose_stream() << "new unit " << lit << "\n");
s.assign_unit(lit);
++m_stats.m_num_units;
}
}
void aig_simplifier::assign_equiv(cut const& c, literal u, literal v) {
if (u.var() == v.var()) return;
IF_VERBOSE(10, verbose_stream() << u << " " << v << " " << c << "\n";);
TRACE("aig_simplifier", tout << u << " == " << v << "\n";);
certify_equivalence(u, v, c);
//validate_eq(u, v);
}
void aig_simplifier::uf2equiv(union_find<> const& uf) {
union_find_default_ctx ctx;
union_find<> uf2(ctx);
bool new_eq = false;
for (unsigned i = 2*s.num_vars(); i--> 0; ) uf2.mk_var();
// extract equivalences over non-eliminated literals.
for (unsigned idx = 0; idx < uf.get_num_vars(); ++idx) {
@ -326,11 +323,10 @@ namespace sat {
}
while (first != idx);
}
if (!new_eq) {
return;
if (new_eq) {
elim_eqs elim(s);
elim(uf2);
}
elim_eqs elim(s);
elim(uf2);
}
/**
@ -396,45 +392,45 @@ namespace sat {
void aig_simplifier::add_dont_cares(vector<cut_set> const& cuts) {
if (m_config.m_enable_dont_cares) {
cuts2pairs(cuts);
pairs2dont_cares();
cuts2bins(cuts);
bins2dont_cares();
dont_cares2cuts(cuts);
}
}
/**
* collect pairs of variables that occur in cut sets.
* collect binary relations between variables that occur in cut sets.
*/
void aig_simplifier::cuts2pairs(vector<cut_set> const& cuts) {
svector<var_pair> dcs;
for (auto const& p : m_pairs) {
void aig_simplifier::cuts2bins(vector<cut_set> const& cuts) {
svector<bin_rel> dcs;
for (auto const& p : m_bins) {
if (p.op != none)
dcs.push_back(p);
}
m_pairs.reset();
m_bins.reset();
for (auto const& cs : cuts) {
for (auto const& c : cs) {
for (unsigned i = c.size(); i-- > 0; ) {
for (unsigned j = i; j-- > 0; ) {
m_pairs.insert(var_pair(c[j],c[i]));
m_bins.insert(bin_rel(c[j],c[i]));
}
}
}
}
// don't lose previous don't cares
for (auto const& p : dcs) {
if (m_pairs.contains(p))
m_pairs.insert(p);
if (m_bins.contains(p))
m_bins.insert(p);
}
}
/**
* compute masks for pairs.
* compute masks for binary relations.
*/
void aig_simplifier::pairs2dont_cares() {
void aig_simplifier::bins2dont_cares() {
big b(s.rand());
b.init(s, true);
for (auto& p : m_pairs) {
for (auto& p : m_bins) {
if (p.op != none) continue;
literal u(p.u, false), v(p.v, false);
// u -> v, then u & ~v is impossible
@ -452,8 +448,8 @@ namespace sat {
}
}
IF_VERBOSE(2, {
unsigned n = 0; for (auto const& p : m_pairs) if (p.op != none) ++n;
verbose_stream() << n << " / " << m_pairs.size() << " don't cares\n";
unsigned n = 0; for (auto const& p : m_bins) if (p.op != none) ++n;
verbose_stream() << n << " / " << m_bins.size() << " don't cares\n";
});
}
@ -476,7 +472,7 @@ namespace sat {
/*
* compute masks for position i, j and op-code p.op
*/
uint64_t aig_simplifier::op2dont_care(unsigned i, unsigned j, var_pair const& p) {
uint64_t aig_simplifier::op2dont_care(unsigned i, unsigned j, bin_rel const& p) {
SASSERT(i < j && j < 6);
if (p.op == none) return 0ull;
// first position of mask is offset into output bits contributed by i and j
@ -496,13 +492,12 @@ namespace sat {
uint64_t dc = 0;
for (unsigned i = 0; i < c.size(); ++i) {
for (unsigned j = i + 1; j < c.size(); ++j) {
var_pair p(c[i], c[j]);
if (m_pairs.find(p, p) && p.op != none) {
bin_rel p(c[i], c[j]);
if (m_bins.find(p, p) && p.op != none) {
dc |= op2dont_care(i, j, p);
}
}
}
}
return (dc != c.dont_care()) && (c.add_dont_care(dc), true);
}
@ -525,7 +520,7 @@ namespace sat {
literal lits1[2] = { a, ~b };
literal lits2[2] = { ~a, b };
m_validator->validate(2, lits1);
m_validator->validate(2, lits1);
m_validator->validate(2, lits2);
}

View file

@ -18,6 +18,7 @@
#pragma once
#include "util/union_find.h"
#include "sat/sat_aig_finder.h"
#include "sat/sat_aig_cuts.h"
@ -56,6 +57,10 @@ namespace sat {
void clauses2aig();
void aig2clauses();
void cuts2equiv(vector<cut_set> const& cuts);
void uf2equiv(union_find<> const& uf);
void assign_unit(literal lit);
void assign_equiv(cut const& c, literal u, literal v);
void ensure_validator();
void validate_unit(literal lit);
void validate_eq(literal a, literal b);
@ -63,40 +68,40 @@ namespace sat {
/**
* collect pairs of literal combinations that are impossible
* base on binary implication graph queries.
* Apply the masks on cut sets so to allow detecting
* equivalences modulo implications.
* base on binary implication graph queries. Apply the masks
* on cut sets so to allow detecting equivalences modulo
* implications.
*/
enum op_code { pp, pn, np, nn, none };
struct var_pair {
struct bin_rel {
unsigned u, v;
op_code op;
var_pair(unsigned _u, unsigned _v): u(_u), v(_v), op(none) {
bin_rel(unsigned _u, unsigned _v): u(_u), v(_v), op(none) {
if (u > v) std::swap(u, v);
}
var_pair(): u(UINT_MAX), v(UINT_MAX), op(none) {}
bin_rel(): u(UINT_MAX), v(UINT_MAX), op(none) {}
struct hash {
unsigned operator()(var_pair const& p) const {
unsigned operator()(bin_rel const& p) const {
return mk_mix(p.u, p.v, 1);
}
};
struct eq {
bool operator()(var_pair const& a, var_pair const& b) const {
bool operator()(bin_rel const& a, bin_rel const& b) const {
return a.u == b.u && a.v == b.v;
}
};
};
hashtable<var_pair, var_pair::hash, var_pair::eq> m_pairs;
hashtable<bin_rel, bin_rel::hash, bin_rel::eq> m_bins;
void add_dont_cares(vector<cut_set> const& cuts);
void cuts2pairs(vector<cut_set> const& cuts);
void pairs2dont_cares();
void cuts2bins(vector<cut_set> const& cuts);
void bins2dont_cares();
void dont_cares2cuts(vector<cut_set> const& cuts);
bool add_dont_care(cut const & c);
uint64_t op2dont_care(unsigned i, unsigned j, var_pair const& p);
uint64_t op2dont_care(unsigned i, unsigned j, bin_rel const& p);
public:
aig_simplifier(solver& s);

View file

@ -32,7 +32,7 @@ namespace sat {
*/
bool cut_set::insert(on_update_t& on_add, on_update_t& on_del, cut const& c) {
unsigned i = 0, j = 0, k = m_size;
unsigned i = 0, k = m_size;
for (; i < k; ++i) {
cut const& a = (*this)[i];
if (a.subset_of(c)) {