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#5778 #5937

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This commit is contained in:
Nikolaj Bjorner 2022-04-01 13:07:17 -07:00
parent 5154295202
commit 81084b8232
6 changed files with 186 additions and 69 deletions
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166
src/sat/smt/array_model.cpp
View file

@ -24,6 +24,11 @@ namespace array {
void solver::init_model() {
collect_defaults();
collect_selects();
}
void solver::finalize_model(model& mdl) {
std::for_each(m_selects_range.begin(), m_selects_range.end(), delete_proc<select_set>());
}
bool solver::add_dep(euf::enode* n, top_sort<euf::enode>& dep) {
@ -103,17 +108,15 @@ namespace array {
if (!get_else(v) && fi->get_else())
set_else(v, fi->get_else());
for (euf::enode* p : euf::enode_parents(n)) {
if (a.is_select(p->get_expr()) && p->get_arg(0)->get_root() == n) {
expr* value = values.get(p->get_root_id(), nullptr);
if (!value || value == fi->get_else())
continue;
args.reset();
for (unsigned i = 1; i < p->num_args(); ++i)
args.push_back(values.get(p->get_arg(i)->get_root_id()));
fi->insert_entry(args.data(), value);
}
for (euf::enode* p : *get_select_set(n)) {
expr* value = values.get(p->get_root_id(), nullptr);
if (!value || value == fi->get_else())
continue;
args.reset();
for (unsigned i = 1; i < p->num_args(); ++i)
args.push_back(values.get(p->get_arg(i)->get_root_id()));
fi->insert_entry(args.data(), value);
}
TRACE("array", tout << "array-as-function " << ctx.bpp(n) << " := " << mk_pp(f, m) << "\n" << "default " << mk_pp(fi->get_else(), m) << "\n";);
@ -135,52 +138,103 @@ namespace array {
return true;
return false;
#if 0
struct eq {
solver& s;
eq(solver& s) :s(s) {}
bool operator()(euf::enode* n1, euf::enode* n2) const {
SASSERT(s.a.is_select(n1->get_expr()));
SASSERT(s.a.is_select(n2->get_expr()));
for (unsigned i = n1->num_args(); i-- > 1; )
if (n1->get_arg(i)->get_root() != n2->get_arg(i)->get_root())
return false;
return true;
}
};
struct hash {
solver& s;
hash(solver& s) :s(s) {}
unsigned operator()(euf::enode* n) const {
SASSERT(s.a.is_select(n->get_expr()));
unsigned h = 33;
for (unsigned i = n->num_args(); i-- > 1; )
h = hash_u_u(h, n->get_arg(i)->get_root_id());
return h;
}
};
eq eq_proc(*this);
hash hash_proc(*this);
hashtable<euf::enode*, hash, eq> table(DEFAULT_HASHTABLE_INITIAL_CAPACITY, hash_proc, eq_proc);
euf::enode* p2 = nullptr;
auto maps_diff = [&](euf::enode* p, euf::enode* else_, euf::enode* r) {
return table.find(p, p2) ? p2->get_root() != r : (else_ && else_ != r);
};
auto table_diff = [&](euf::enode* r1, euf::enode* r2, euf::enode* else1) {
table.reset();
for (euf::enode* p : euf::enode_parents(r1))
if (a.is_select(p->get_expr()) && r1 == p->get_arg(0)->get_root())
table.insert(p);
for (euf::enode* p : euf::enode_parents(r2))
if (a.is_select(p->get_expr()) && r2 == p->get_arg(0)->get_root())
if (maps_diff(p, else1, p->get_root()))
return true;
return false;
};
return table_diff(r1, r2, else1) || table_diff(r2, r1, else2);
}
#endif
unsigned solver::sel_hash::operator()(euf::enode * n) const {
return get_composite_hash<euf::enode *, sel_khasher, sel_chasher>(n, n->num_args() - 1, sel_khasher(), sel_chasher());
}
bool solver::sel_eq::operator()(euf::enode * n1, euf::enode * n2) const {
SASSERT(n1->num_args() == n2->num_args());
unsigned num_args = n1->num_args();
for (unsigned i = 1; i < num_args; i++)
if (n1->get_arg(i)->get_root() != n2->get_arg(i)->get_root())
return false;
return true;
}
void solver::collect_selects() {
int num_vars = get_num_vars();
m_selects.reset();
m_selects_domain.reset();
m_selects_range.reset();
for (theory_var v = 0; v < num_vars; ++v) {
euf::enode * r = var2enode(v)->get_root();
if (is_representative(v) && ctx.is_relevant(r)) {
for (euf::enode * parent : euf::enode_parents(r)) {
if (parent->get_cg() == parent &&
ctx.is_relevant(parent) &&
a.is_select(parent->get_expr()) &&
parent->get_arg(0)->get_root() == r) {
select_set * s = get_select_set(r);
SASSERT(!s->contains(parent) || (*(s->find(parent)))->get_root() == parent->get_root());
s->insert(parent);
}
}
}
}
euf::enode_pair_vector todo;
for (euf::enode * r : m_selects_domain)
for (euf::enode* sel : *get_select_set(r))
propagate_select_to_store_parents(r, sel, todo);
for (unsigned qhead = 0; qhead < todo.size(); qhead++) {
euf::enode_pair & pair = todo[qhead];
euf::enode * r = pair.first;
euf::enode * sel = pair.second;
propagate_select_to_store_parents(r, sel, todo);
}
}
void solver::propagate_select_to_store_parents(euf::enode* r, euf::enode* sel, euf::enode_pair_vector& todo) {
SASSERT(r->get_root() == r);
SASSERT(a.is_select(sel->get_expr()));
if (!ctx.is_relevant(r))
return;
for (euf::enode * parent : euf::enode_parents(r)) {
if (ctx.is_relevant(parent) &&
a.is_store(parent->get_expr()) &&
parent->get_arg(0)->get_root() == r) {
// propagate upward
select_set * parent_sel_set = get_select_set(parent);
euf::enode * parent_root = parent->get_root();
if (parent_sel_set->contains(sel))
continue;
SASSERT(sel->num_args() + 1 == parent->num_args());
// check whether the sel idx was overwritten by the store
unsigned num_args = sel->num_args();
unsigned i = 1;
for (; i < num_args; i++) {
if (sel->get_arg(i)->get_root() != parent->get_arg(i)->get_root())
break;
}
if (i < num_args) {
SASSERT(!parent_sel_set->contains(sel) || (*(parent_sel_set->find(sel)))->get_root() == sel->get_root());
parent_sel_set->insert(sel);
todo.push_back(std::make_pair(parent_root, sel));
}
}
}
}
solver::select_set* solver::get_select_set(euf::enode* n) {
euf::enode * r = n->get_root();
select_set * set = nullptr;
m_selects.find(r, set);
if (set == nullptr) {
set = alloc(select_set);
m_selects.insert(r, set);
m_selects_domain.push_back(r);
m_selects_range.push_back(set);
}
return set;
}
void solver::collect_defaults() {

29
src/sat/smt/array_solver.h
View file

@ -218,11 +218,39 @@ namespace array {
void pop_core(unsigned n) override;
// models
// I need a set of select enodes where select(A,i) = select(B,j) if i->get_root() == j->get_root()
struct sel_khasher {
unsigned operator()(euf::enode const * n) const { return 0; }
};
struct sel_chasher {
unsigned operator()(euf::enode const * n, unsigned idx) const {
return n->get_arg(idx+1)->get_root()->hash();
}
};
struct sel_hash {
unsigned operator()(euf::enode * n) const;
};
struct sel_eq {
bool operator()(euf::enode * n1, euf::enode * n2) const;
};
typedef ptr_hashtable<euf::enode, sel_hash, sel_eq> select_set;
euf::enode_vector m_defaults; // temporary field for model construction
ptr_vector<expr> m_else_values; //
svector<int> m_parents; // temporary field for model construction
obj_map<euf::enode, select_set*> m_selects; // mapping from array -> relevant selects
ptr_vector<euf::enode> m_selects_domain;
ptr_vector<select_set> m_selects_range;
bool must_have_different_model_values(theory_var v1, theory_var v2);
select_set* get_select_set(euf::enode* n);
void collect_defaults();
void collect_selects(); // mapping from array -> relevant selects
void propagate_select_to_store_parents(euf::enode* r, euf::enode* sel, euf::enode_pair_vector& todo);
void mg_merge(theory_var u, theory_var v);
theory_var mg_find(theory_var n);
void set_default(theory_var v, euf::enode* n);
@ -254,6 +282,7 @@ namespace array {
void new_diseq_eh(euf::th_eq const& eq) override;
bool unit_propagate() override;
void init_model() override;
void finalize_model(model& mdl) override;
bool include_func_interp(func_decl* f) const override { return a.is_ext(f); }
void add_value(euf::enode* n, model& mdl, expr_ref_vector& values) override;
bool add_dep(euf::enode* n, top_sort<euf::enode>& dep) override;

1
src/sat/smt/sat_th.h
View file

@ -188,6 +188,7 @@ namespace euf {
enode* expr2enode(expr* e) const;
enode* var2enode(theory_var v) const { return m_var2enode[v]; }
expr* var2expr(theory_var v) const { return var2enode(v)->get_expr(); }
bool is_representative(theory_var v) const { return v == get_representative(v); }
expr* bool_var2expr(sat::bool_var v) const;
expr_ref literal2expr(sat::literal lit) const;
enode* bool_var2enode(sat::bool_var v) const { expr* e = bool_var2expr(v); return e ? expr2enode(e) : nullptr; }