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Fixed "external"

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This commit is contained in:
Clemens Eisenhofer 2022-12-04 17:16:33 +01:00
parent c0f44af643
commit 4c76e43322
3 changed files with 57 additions and 24 deletions
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3
src/sat/smt/xor_gaussian.cpp
View file

@ -400,7 +400,8 @@ static void print_matrix(ostream& out, PackedMatrix& mat) {
// Applies Gaussian-Jordan elimination (search level). This function does not add conflicts/propagate/... Just reduces the matrix
void EGaussian::eliminate() {
// TODO: Why twice? gauss_jordan_elim
SASSERT(m_solver.s().at_search_lvl());
unsigned end_row = num_rows;
unsigned rowI = 0;
unsigned row_i = 0;

73
src/sat/smt/xor_solver.cpp
View file

@ -94,6 +94,7 @@ namespace xr {
rhs ^= true;
lit.neg();
}
s().set_external(lit.var());
}
clean_xor_no_prop(ps, rhs);
@ -131,11 +132,10 @@ namespace xr {
if (m_prop_queue_head == m_prop_queue.size())
return false;
force_push();
m_ctx->push(value_trail<unsigned>(m_prop_queue_head));
for (; m_prop_queue_head < m_prop_queue.size() && !s().inconsistent(); ++m_prop_queue_head) {
sat::literal const p = m_prop_queue[m_prop_queue_head];
sat::justification conflict = gauss_jordan_elim(p, m_num_scopes);
if (conflict.is_none()) {
if (!conflict.is_none()) {
m_prop_queue_head = m_prop_queue.size();
s().set_conflict(conflict);
}
@ -238,6 +238,7 @@ namespace xr {
void solver::push_core() {
m_prop_queue_lim.push_back(m_prop_queue.size());
m_prop_queue_head_queue.push_back(m_prop_queue_head);
//m_justifications_lim.push_back(m_justifications.size());
}
@ -247,6 +248,9 @@ namespace xr {
m_prop_queue.shrink(m_prop_queue_lim[old_sz]);
m_prop_queue_lim.shrink(old_sz);
m_prop_queue_head = m_prop_queue_head_queue[old_sz];
m_prop_queue_head_queue.shrink(old_sz);
/*old_sz = m_justifications_lim.size() - num_scopes;
unsigned lim = m_justifications_lim[old_sz];
for (unsigned i = m_justifications.size(); i > lim; i--) {
@ -583,6 +587,11 @@ namespace xr {
if (xors.empty())
return !s().inconsistent();
if (s().is_incremental()) { // TODO: What should we do in this case?
clean_xors_from_empty(xors);
return !s().inconsistent();
}
if (m_occ_cnt.size() != s().num_vars()) {
m_occ_cnt.clear();
m_occ_cnt.resize(s().num_vars(), 0);
@ -613,25 +622,7 @@ namespace xr {
}
}
s().init_visited();
// We can only eliminate variables that are non-external and not used in clauses.
// Don't XOR together over variables that are external
for (unsigned i = 0; i < s().num_vars(); i++)
if (s().is_external(i))
s().mark_visited(i);
// Don't XOR together over variables that are in irredundant clauses
// learned clauses are redundant.
for (unsigned i = 0; i < 2 * s().num_vars(); i++)
for (const auto& w: s().get_wlist(i))
if (w.is_binary_clause() && !w.is_learned())
s().mark_visited(w.get_literal().var());
for (const auto& cl: s().clauses())
if (!cl->is_learned())
for (literal l: *cl)
s().mark_visited(l.var());
mark_non_removable_atoms();
// until fixedpoint
bool changed = true;
@ -731,8 +722,6 @@ namespace xr {
return !s().inconsistent();
}
// Removes all xor clauses that do not contain any variables
// (and have rhs = false; i.e., are trivially satisfied) and move them to unused
void solver::clean_xors_from_empty(vector<xor_clause>& thisxors) {
@ -748,6 +737,44 @@ namespace xr {
thisxors.shrink(j);
}
// marks all elements that may NOT be removed by merging xors
void solver::mark_non_removable_atoms() {
s().init_visited();
// We can only eliminate variables that are non-external and not used in clauses.
// Don't XOR together over variables that are external
for (bool_var v = 0; v < s().num_vars(); v++) {
if (!s().is_external(v)) // We can ignore this case, as all variables in xor-clauses are marked as external for sure
continue;
if (is_theory_atom(v))
s().mark_visited(v);
}
// Don't XOR together over variables that are in irredundant clauses
// learned clauses are redundant.
for (unsigned i = 0; i < 2 * s().num_vars(); i++)
for (const auto& w: s().get_wlist(i))
if (w.is_binary_clause() && !w.is_learned())
s().mark_visited(w.get_literal().var());
for (const auto& cl: s().clauses())
if (!cl->is_learned())
for (literal l: *cl)
s().mark_visited(l.var());
}
bool solver::is_theory_atom(bool_var v) const {
if (m_ctx == nullptr)
return false; // there is no other solver
euf::enode* n = m_ctx->bool_var2enode(v);
if (!n)
return false;
auto th_vars = euf::enode_th_vars(n);
return std::any_of(th_vars.begin(), th_vars.end(), [&](const euf::th_var_list& thv) { return m_ctx->fid2solver(thv.get_id()); });
}
// Merge two xor clauses; the resulting clause is in m_tmp_vars_xor_two and the variable where it was glued is in clash_var
// returns 0 if no common variable was found, 1 if there was exactly one and 2 if there are more
// only 1 is successful

5
src/sat/smt/xor_solver.h
View file

@ -31,7 +31,9 @@ namespace xr {
literal_vector m_prop_queue;
unsigned_vector m_prop_queue_lim;
unsigned m_prop_queue_head = 0;
unsigned_vector m_prop_queue_head_queue;
// ptr_vector<justification> m_justifications;
// unsigned_vector m_justifications_lim;
@ -73,6 +75,9 @@ namespace xr {
void clean_occur_from_idx(const literal l);
void clean_xors_from_empty(vector<xor_clause>& thisxors);
bool is_theory_atom(bool_var v) const;
void mark_non_removable_atoms();
unsigned xor_two(xor_clause const* x1_p, xor_clause const* x2_p, bool_var& clash_var);
bool add_simple_xor_constraint(const xor_clause& constraint);