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expand table constraints; improve cut management; speed up presolve

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This commit is contained in:
Laurent Perron
2020-03-19 00:24:10 +01:00
parent 0d6f6dddd9
commit a0cc52731e
15 changed files with 517 additions and 147 deletions
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18
ortools/sat/simplification.cc
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@@ -301,7 +301,7 @@ bool SatPresolver::ProcessAllClauses() {
clause_to_process_.pop_front();
if (!ProcessClauseToSimplifyOthers(ci)) return false;
if (++num_skipped_checks >= kCheckFrequency) {
if (num_inspected_signatures_ > 1e9) {
if (num_inspected_signatures_ + num_inspected_literals_ > 1e9) {
VLOG(1) << "Aborting ProcessAllClauses() because work limit has been "
"reached";
return true;
@@ -332,6 +332,7 @@ bool SatPresolver::Presolve(const std::vector<bool>& can_be_removed) {
DisplayStats(timer.Get());
if (time_limit_ != nullptr && time_limit_->LimitReached()) return true;
if (num_inspected_signatures_ + num_inspected_literals_ > 1e9) return true;
InitializePriorityQueue();
while (var_pq_.Size() > 0) {
@@ -341,6 +342,8 @@ bool SatPresolver::Presolve(const std::vector<bool>& can_be_removed) {
if (CrossProduct(Literal(var, true))) {
if (!ProcessAllClauses()) return false;
}
if (time_limit_ != nullptr && time_limit_->LimitReached()) return true;
if (num_inspected_signatures_ + num_inspected_literals_ > 1e9) return true;
}
DisplayStats(timer.Get());
@@ -557,7 +560,8 @@ bool SatPresolver::ProcessClauseToSimplifyOthersUsingLiteral(
// 'a' are a subset of the one in 'b'. We use the signatures to abort
// early as a speed optimization.
if (ci != clause_index && (clause_signature & ~ci_signature) == 0 &&
SimplifyClause(clause, &clauses_[ci], &opposite_literal)) {
SimplifyClause(clause, &clauses_[ci], &opposite_literal,
&num_inspected_literals_)) {
if (opposite_literal == kNoLiteralIndex) {
need_cleaning = true;
Remove(ci);
@@ -641,7 +645,8 @@ bool SatPresolver::ProcessClauseToSimplifyOthers(ClauseIndex clause_index) {
// applies to the second call to
// ProcessClauseToSimplifyOthersUsingLiteral() above too.
if ((clause_signature & ~ci_signature) == 0 &&
SimplifyClause(clause, &clauses_[ci], &opposite_literal)) {
SimplifyClause(clause, &clauses_[ci], &opposite_literal,
&num_inspected_literals_)) {
DCHECK_EQ(opposite_literal, lit.NegatedIndex());
if (clauses_[ci].empty()) return false; // UNSAT.
if (drat_proof_handler_ != nullptr) {
@@ -910,10 +915,15 @@ void SatPresolver::DisplayStats(double elapsed_seconds) {
}
bool SimplifyClause(const std::vector<Literal>& a, std::vector<Literal>* b,
LiteralIndex* opposite_literal) {
LiteralIndex* opposite_literal,
int64* num_inspected_literals) {
if (b->size() < a.size()) return false;
DCHECK(std::is_sorted(a.begin(), a.end()));
DCHECK(std::is_sorted(b->begin(), b->end()));
if (num_inspected_literals != nullptr) {
*num_inspected_literals += a.size();
*num_inspected_literals += b->size();
}
*opposite_literal = LiteralIndex(-1);