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working on sub/super slices

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2023-12-22 17:45:23 -08:00
parent 9a7e50c1e8
commit 5bbec43235
4 changed files with 134 additions and 24 deletions
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14
src/sat/smt/polysat/types.h
View file

@ -90,6 +90,16 @@ namespace polysat {
fixed_bits(unsigned hi, unsigned lo, rational value) : hi(hi), lo(lo), value(value) {}
};
struct justified_slice {
pvar v;
unsigned offset;
dependency dep;
};
inline std::ostream& operator<<(std::ostream& out, justified_slice const& js) {
return out << "v" << js.v << "[" << js.offset << "[ @" << js.dep;
}
using justified_fixed_bits = vector<std::pair<fixed_bits, dependency>>;
using dependency_vector = vector<dependency>;
@ -100,7 +110,7 @@ namespace polysat {
using core_vector = std::initializer_list<constraint_or_dependency>;
using constraint_id_vector = svector<constraint_id>;
using constraint_id_list = std::initializer_list<constraint_id>;
using justified_slices = vector<std::pair<pvar, dependency>>;
using justified_slices = vector<justified_slice>;
using eq_justification = svector<std::pair<theory_var, theory_var>>;
//
@ -118,6 +128,8 @@ namespace polysat {
virtual trail_stack& trail() = 0;
virtual bool inconsistent() const = 0;
virtual void get_bitvector_suffixes(pvar v, justified_slices& out) = 0;
virtual void get_bitvector_sub_slices(pvar v, justified_slices& out) = 0;
virtual void get_bitvector_super_slices(pvar v, justified_slices& out) = 0;
virtual void get_fixed_bits(pvar v, justified_fixed_bits& fixed_bits) = 0;
};

8
src/sat/smt/polysat/viable.cpp
View file

@ -105,13 +105,13 @@ namespace polysat {
justified_slices overlaps;
c.get_bitvector_suffixes(v, overlaps);
std::sort(overlaps.begin(), overlaps.end(), [&](auto const& x, auto const& y) { return c.size(x.first) > c.size(y.first); });
std::sort(overlaps.begin(), overlaps.end(), [&](auto const& x, auto const& y) { return c.size(x.v) > c.size(y.v); });
uint_set widths_set;
// max size should always be present, regardless of whether we have intervals there (to make sure all fixed bits are considered)
widths_set.insert(c.size(v));
for (auto const& [v, j] : overlaps)
for (auto const& [v, offset, j] : overlaps)
for (layer const& l : m_units[v].get_layers())
widths_set.insert(l.bit_width);
@ -176,7 +176,7 @@ namespace polysat {
// however, we probably should rotate to avoid getting stuck in refinement loop on a 'bad' constraint
bool refined = false;
for (unsigned i = overlaps.size(); i-- > 0; ) {
pvar x = overlaps[i].first;
pvar x = overlaps[i].v;
rational const& mod_value = c.var2pdd(x).two_to_N();
rational x_val = mod(val, mod_value);
if (!refine_viable(x, x_val)) {
@ -240,7 +240,7 @@ namespace polysat {
// find relevant interval lists
svector<entry_cursor> ecs;
for (auto const& [x, j] : overlaps) {
for (auto const& [x, offset, j] : overlaps) {
if (c.size(x) < w) // note that overlaps are sorted by variable size descending
break;
if (entry* e = m_units[x].get_entries(w)) {

129
src/sat/smt/polysat_egraph.cpp
View file

@ -36,7 +36,7 @@ namespace polysat {
}
};
void solver::get_subslices(pvar pv, subslice_infos& slices) {
void solver::get_sub_slices(pvar pv, slice_infos& slices) {
theory_var v = m_pddvar2var[pv];
unsigned lo, hi;
expr* e = nullptr;
@ -60,11 +60,11 @@ namespace polysat {
}
}
for (auto p : euf::enode_parents(n->get_root())) {
if (p->is_marked1())
if (p->get_root()->is_marked1())
continue;
if (bv.is_extract(p->get_expr(), lo, hi, e)) {
auto child = expr2enode(e);
SASSERT(n == child->get_root());
SASSERT(n->get_root() == child->get_root());
scoped_eq_justification sp(*this, just, child, n);
slices.push_back({ p, offset + lo, just });
}
@ -74,41 +74,136 @@ namespace polysat {
n->get_root()->unmark1();
}
void solver::get_super_slices(pvar pv, slice_infos& slices) {
theory_var v = m_pddvar2var[pv];
unsigned lo, hi;
expr* e = nullptr;
euf::enode* n = var2enode(v);
slices.push_back({ n, 0, {} });
// walk the egraph starting with pvar for overlaps.
for (unsigned i = 0; i < slices.size(); ++i) {
auto [n, offset, just] = slices[i];
if (n->get_root()->is_marked1())
continue;
n->get_root()->mark1();
for (auto sib : euf::enode_class(n)) {
if (bv.is_extract(sib->get_expr(), lo, hi, e)) {
auto child = expr2enode(e);
SASSERT(n->get_root() == child->get_root());
scoped_eq_justification sp(*this, just, child, n);
slices.push_back({ sib, offset + lo, just });
}
}
for (auto p : euf::enode_parents(n->get_root())) {
if (p->get_root()->is_marked1())
continue;
if (bv.is_concat(p->get_expr())) {
unsigned delta = 0;
for (unsigned j = p->num_args(); j-- > 0; ) {
auto arg = p->get_arg(j);
if (arg->get_root() == n->get_root()) {
scoped_eq_justification sp(*this, just, arg, n);
slices.push_back({ p, offset + delta, just });
}
delta += bv.get_bv_size(arg->get_expr());
}
}
}
}
for (auto const& [n, offset, d] : slices)
n->get_root()->unmark1();
}
// walk the egraph starting with pvar for suffix overlaps.
void solver::get_bitvector_suffixes(pvar pv, justified_slices& out) {
subslice_infos slices;
get_subslices(pv, slices);
slice_infos slices;
get_sub_slices(pv, slices);
uint_set seen;
for (auto& [n, offset, just] : slices) {
if (offset != 0)
continue;
auto w = n->get_th_var(get_id());
if (w == euf::null_theory_var)
continue;
auto const& p = m_var2pdd[w];
if (p.is_var())
out.push_back({ p.var(), dependency(just, s().scope_lvl())}); // approximate to current scope
for (auto sib : euf::enode_class(n)) {
auto w = sib->get_th_var(get_id());
if (w == euf::null_theory_var)
continue;
if (seen.contains(w))
continue;
seen.insert(w);
auto const& p = m_var2pdd[w];
if (!p.is_var())
continue;
scoped_eq_justification sp(*this, just, sib, n);
out.push_back({ p.var(), offset, dependency(just, s().scope_lvl()) }); // approximate to current scope
}
}
}
// walk the egraph starting with pvar for any overlaps.
void solver::get_bitvector_sub_slices(pvar pv, justified_slices& out) {
slice_infos slices;
get_sub_slices(pv, slices);
uint_set seen;
for (auto& [n, offset, just] : slices) {
for (auto sib : euf::enode_class(n)) {
auto w = sib->get_th_var(get_id());
if (w == euf::null_theory_var)
continue;
if (seen.contains(w))
continue;
seen.insert(w);
auto const& p = m_var2pdd[w];
if (!p.is_var())
continue;
scoped_eq_justification sp(*this, just, sib, n);
out.push_back({ p.var(), offset, dependency(just, s().scope_lvl()) }); // approximate to current scope
}
}
}
// walk the egraph for bit-vectors that contain pv.
void solver::get_bitvector_super_slices(pvar pv, justified_slices& out) {
slice_infos slices;
get_super_slices(pv, slices);
uint_set seen;
for (auto& [n, offset, just] : slices) {
for (auto sib : euf::enode_class(n)) {
auto w = sib->get_th_var(get_id());
if (w == euf::null_theory_var)
continue;
if (seen.contains(w))
continue;
seen.insert(w);
auto const& p = m_var2pdd[w];
if (!p.is_var())
continue;
scoped_eq_justification sp(*this, just, sib, n);
out.push_back({ p.var(), offset, dependency(just, s().scope_lvl()) }); // approximate to current scope
}
}
}
// walk the e-graph to retrieve fixed overlaps
void solver::get_fixed_bits(pvar pv, justified_fixed_bits& out) {
subslice_infos slices;
get_subslices(pv, slices);
slice_infos slices;
get_sub_slices(pv, slices);
for (auto& [n, offset, just] : slices) {
if (offset != 0)
continue;
n = n->get_root();
if (!n->interpreted())
if (!n->get_root()->interpreted())
continue;
auto w = n->get_th_var(get_id());
auto w = n->get_root()->get_th_var(get_id());
if (w == euf::null_theory_var)
continue;
auto const& p = m_var2pdd[w];
if (!p.is_var())
continue;
scoped_eq_justification sp(*this, just, n, n->get_root());
unsigned lo = offset, hi = bv.get_bv_size(n->get_expr());
rational value;
VERIFY(bv.is_numeral(n->get_expr(), value));

7
src/sat/smt/polysat_solver.h
View file

@ -34,7 +34,7 @@ namespace polysat {
typedef sat::literal literal;
typedef sat::bool_var bool_var;
typedef sat::literal_vector literal_vector;
using subslice_infos = vector<std::tuple<euf::enode*, unsigned, eq_justification>>;
using slice_infos = vector<std::tuple<euf::enode*, unsigned, eq_justification>>;
using pdd = dd::pdd;
struct stats {
@ -75,7 +75,8 @@ namespace polysat {
sat::check_result intblast();
void get_subslices(pvar v, subslice_infos& slices);
void get_sub_slices(pvar v, slice_infos& slices);
void get_super_slices(pvar v, slice_infos& slices);
// internalize
bool visit(expr* e) override;
@ -169,6 +170,8 @@ namespace polysat {
void propagate(dependency const& d, bool sign, constraint_id_vector const& deps) override;
trail_stack& trail() override;
bool inconsistent() const override;
void get_bitvector_sub_slices(pvar v, justified_slices& out) override;
void get_bitvector_super_slices(pvar v, justified_slices& out) override;
void get_bitvector_suffixes(pvar v, justified_slices& out) override;
void get_fixed_bits(pvar v, justified_fixed_bits& fixed_bits) override;