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Polysat: use constraint_literal and begin move to core-based conflict representation (#5489)

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* Rename solver_scope for fixplex tests

(otherwise the wrong constructor is called for polysat's solver_scope)

* Update conflict_core

* simplify

* Be clearer about constraint_literal lifetime

* remove old comment

* Remove status (positive/negative) from constraint

* Use constraint_literal in the solver

* Fix build (constraint -> get_constraint)
This commit is contained in:
Jakob Rath 2021-08-18 20:02:46 +02:00 • committed by GitHub
parent 30e9f24fa3
commit ebaea2159e
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GPG key ID: 4AEE18F83AFDEB23
19 changed files with 933 additions and 1004 deletions
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78
src/math/polysat/constraint.cpp
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@ -93,6 +93,10 @@ namespace polysat {
return get_bv2c(var);
}
constraint_literal constraint_manager::lookup(sat::literal lit) const {
return {lit, lookup(lit.var())};
}
eq_constraint& constraint::to_eq() {
return *dynamic_cast<eq_constraint*>(this);
}
@ -109,16 +113,16 @@ namespace polysat {
return *dynamic_cast<ule_constraint const*>(this);
}
constraint_literal constraint_manager::eq(unsigned lvl, pdd const& p) {
return constraint_literal{alloc(eq_constraint, *this, lvl, p)};
constraint_literal_ref constraint_manager::eq(unsigned lvl, pdd const& p) {
return constraint_literal_ref{alloc(eq_constraint, *this, lvl, p)};
}
constraint_literal constraint_manager::ule(unsigned lvl, pdd const& a, pdd const& b) {
return constraint_literal{alloc(ule_constraint, *this, lvl, a, b)};
constraint_literal_ref constraint_manager::ule(unsigned lvl, pdd const& a, pdd const& b) {
return constraint_literal_ref{alloc(ule_constraint, *this, lvl, a, b)};
}
constraint_literal constraint_manager::ult(unsigned lvl, pdd const& a, pdd const& b) {
constraint_literal_ref constraint_manager::ult(unsigned lvl, pdd const& a, pdd const& b) {
// a < b <=> !(b <= a)
return ~ule(lvl, b, a);
}
@ -139,25 +143,26 @@ namespace polysat {
//
// Argument: flipping the msb swaps the negative and non-negative blocks
//
constraint_literal constraint_manager::sle(unsigned lvl, pdd const& a, pdd const& b) {
constraint_literal_ref constraint_manager::sle(unsigned lvl, pdd const& a, pdd const& b) {
auto shift = rational::power_of_two(a.power_of_2() - 1);
return ule(lvl, a + shift, b + shift);
}
constraint_literal constraint_manager::slt(unsigned lvl, pdd const& a, pdd const& b) {
constraint_literal_ref constraint_manager::slt(unsigned lvl, pdd const& a, pdd const& b) {
auto shift = rational::power_of_two(a.power_of_2() - 1);
return ult(lvl, a + shift, b + shift);
}
std::ostream& constraint::display_extra(std::ostream& out) const {
std::ostream& constraint::display_extra(std::ostream& out, lbool status) const {
out << " @" << level() << " (b" << bvar() << ")";
if (is_positive()) out << " [pos]";
if (is_negative()) out << " [neg]";
if (is_undef()) out << " [inactive]";
(void)status;
// if (is_positive()) out << " [pos]";
// if (is_negative()) out << " [neg]";
// if (is_undef()) out << " [inactive]"; // TODO: not sure if we still need/want this... decide later
return out;
}
bool constraint::propagate(solver& s, pvar v) {
bool constraint::propagate(solver& s, bool is_positive, pvar v) {
LOG_H3("Propagate " << s.m_vars[v] << " in " << *this);
SASSERT(!vars().empty());
unsigned idx = 0;
@ -168,24 +173,35 @@ namespace polysat {
for (unsigned i = vars().size(); i-- > 2; ) {
unsigned other_v = vars()[i];
if (!s.is_assigned(other_v)) {
s.add_watch(*this, other_v);
s.add_watch({this, is_positive}, other_v);
std::swap(vars()[idx], vars()[i]);
return true;
}
}
// at most one variable remains unassigned.
unsigned other_v = vars()[idx];
propagate_core(s, v, other_v);
propagate_core(s, is_positive, v, other_v);
return false;
}
void constraint::propagate_core(solver& s, pvar v, pvar other_v) {
void constraint::propagate_core(solver& s, bool is_positive, pvar v, pvar other_v) {
(void)v;
(void)other_v;
narrow(s);
narrow(s, is_positive);
}
clause_ref clause::from_unit(constraint_literal c, p_dependency_ref d) {
std::ostream &constraint_literal::display(std::ostream &out) const {
if (*this)
return out << m_literal << "{ " << *m_constraint << " }";
else
return out << "<null>";
}
std::ostream &constraint_literal_ref::display(std::ostream &out) const {
return out << get();
}
clause_ref clause::from_unit(constraint_literal_ref c, p_dependency_ref d) {
SASSERT(c);
unsigned const lvl = c->level();
sat::literal_vector lits;
@ -201,17 +217,15 @@ namespace polysat {
bool clause::is_always_false(solver& s) const {
return std::all_of(m_literals.begin(), m_literals.end(), [&s](sat::literal lit) {
constraint *c = s.m_constraints.lookup(lit.var());
tmp_assign _t(c, lit);
return c->is_always_false();
constraint_literal c = s.m_constraints.lookup(lit);
return c.is_always_false();
});
}
bool clause::is_currently_false(solver& s) const {
return std::all_of(m_literals.begin(), m_literals.end(), [&s](sat::literal lit) {
constraint *c = s.m_constraints.lookup(lit.var());
tmp_assign _t(c, lit);
return c->is_currently_false(s);
constraint_literal c = s.m_constraints.lookup(lit);
return c.is_currently_false(s);
});
}
@ -251,22 +265,4 @@ namespace polysat {
return out;
}
std::ostream& constraints_and_clauses::display(std::ostream& out) const {
bool first = true;
for (auto c : units()) {
if (first)
first = false;
else
out << " ; ";
out << show_deref(c);
}
for (auto cl : clauses()) {
if (first)
first = false;
else
out << " ; ";
out << show_deref(cl);
}
return out;
}
}