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Polysat: constraint refactor cont'd, deduplicate constraints (#5520)

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* Assign boolean variables only to long-lived constraints, and deduplicate constraints when they are created

* scoped_signed_constraint

* update other classes

* fix

* Don't use scoped_ptr<constraint> with dedup()
This commit is contained in:
Jakob Rath 2021-08-30 19:00:27 +02:00 • committed by GitHub
parent ebaea2159e
commit 0c1e44da77
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GPG key ID: 4AEE18F83AFDEB23
16 changed files with 365 additions and 298 deletions
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21
src/math/polysat/forbidden_intervals.cpp
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@ -22,8 +22,8 @@ namespace polysat {
struct fi_record {
eval_interval interval;
constraint_literal_ref neg_cond; // could be multiple constraints later
constraint_literal src;
scoped_signed_constraint neg_cond; // could be multiple constraints later
signed_constraint src;
};
/**
@ -64,17 +64,17 @@ namespace polysat {
return true;
}
bool forbidden_intervals::explain(solver& s, vector<constraint_literal> const& conflict, pvar v, clause_ref& out_lemma) {
bool forbidden_intervals::explain(solver& s, vector<signed_constraint> const& conflict, pvar v, clause_ref& out_lemma) {
// Extract forbidden intervals from conflicting constraints
vector<fi_record> records;
bool has_full = false;
rational longest_len;
unsigned longest_i = UINT_MAX;
for (constraint_literal c : conflict) {
for (signed_constraint c : conflict) {
LOG_H3("Computing forbidden interval for: " << c);
eval_interval interval = eval_interval::full();
constraint_literal_ref neg_cond;
scoped_signed_constraint neg_cond;
if (c->forbidden_interval(s, c.is_positive(), v, interval, neg_cond)) {
LOG("interval: " << interval);
LOG("neg_cond: " << neg_cond);
@ -102,7 +102,8 @@ namespace polysat {
auto& full_record = records.back();
SASSERT(full_record.interval.is_full());
clause_builder clause(s);
clause.push_literal(~full_record.src.literal());
sat::literal src_lit = full_record.src.blit();
clause.push_literal(~src_lit);
if (full_record.neg_cond)
clause.push_new_constraint(std::move(full_record.neg_cond));
out_lemma = clause.build();
@ -130,7 +131,7 @@ namespace polysat {
unsigned lemma_lvl = 0;
for (unsigned i : seq) {
constraint_literal const& c = records[i].src;
signed_constraint const& c = records[i].src;
lemma_lvl = std::max(lemma_lvl, c->level());
}
@ -145,7 +146,7 @@ namespace polysat {
clause_builder clause(s);
// Add negation of src constraints as antecedents (may be resolved during backtracking)
for (unsigned const i : seq) {
sat::literal src_lit = records[i].src.literal();
sat::literal src_lit = records[i].src.blit();
clause.push_literal(~src_lit);
}
// Add side conditions and interval constraints
@ -159,12 +160,12 @@ namespace polysat {
auto const& next_hi = records[next_i].interval.hi();
auto const& lhs = hi - next_lo;
auto const& rhs = next_hi - next_lo;
constraint_literal_ref c = ~s.m_constraints.ult(lemma_lvl, lhs, rhs);
scoped_signed_constraint c = ~s.m_constraints.ult(lemma_lvl, lhs, rhs);
LOG("constraint: " << c);
clause.push_new_constraint(std::move(c));
// Side conditions
// TODO: check whether the condition is subsumed by c? maybe at the end do a "lemma reduction" step, to try and reduce branching?
constraint_literal_ref& neg_cond = records[i].neg_cond;
scoped_signed_constraint& neg_cond = records[i].neg_cond;
if (neg_cond)
clause.push_new_constraint(std::move(neg_cond));
}