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try more bound propagation

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Signed-off-by: Lev Nachmanson <levnach@hotmail.com>
This commit is contained in:
Lev Nachmanson 2025-03-08 15:18:53 -10:00
parent 4adcc21e37
commit 55eb539534
1 changed files with 31 additions and 19 deletions
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50
src/math/lp/dioph_eq.cpp
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@ -1151,13 +1151,17 @@ namespace lp {
return ret;
}
bool has_fresh_var(unsigned row_index) const {
for (const auto& p : m_e_matrix.m_rows[row_index]) {
template <typename T>
bool has_fresh_var(const T& t) const {
for (const auto& p : t) {
if (var_is_fresh(p.var()))
return true;
}
return false;
}
bool has_fresh_var(unsigned row_index) const {
return has_fresh_var(m_e_matrix[row_index]);
}
// A conflict is reported when the gcd of the monomial coefficients does not divide the free coefficent.
// If there is no conflict the entry is divided, normalized, by gcd.
@ -1495,23 +1499,15 @@ namespace lp {
return out;
}
// h is the entry that is ready to be moved to S
lia_move tighten_bounds(unsigned h) {
SASSERT(entry_invariant(h));
protected_queue q;
copy_row_to_espace(h);
remove_fresh_from_espace();
template <typename T>
lia_move propagate_bounds_on_espace(const mpq& sum_of_fixed, const T& meta_term) {
// change m_espace indices from local to lar_solver: have to restore for clear to work
if (has_fresh_var(m_espace)) return lia_move::undef;
for (auto & p: m_espace.m_data) {
SASSERT(!var_is_fresh(p.m_j));
p.m_j = local_to_lar_solver(p.m_j);
p.m_j = local_to_lar_solver(p.m_j);
}
TRACE("dio", tout << "bp on entry:"; print_entry(h, tout) << std::endl;);
m_prop_bounds.clear();
bound_analyzer_on_row<term_with_index, dioph_eq::imp>::analyze_row(m_espace, impq(-m_sum_of_fixed[h]), *this);
bound_analyzer_on_row<term_with_index, dioph_eq::imp>::analyze_row(m_espace, impq(-sum_of_fixed), *this);
//restore m_espace to local variables
for (auto & p: m_espace.m_data) p.m_j = lar_solver_to_local(p.m_j);
if (m_prop_bounds.size() == 0) {
@ -1519,7 +1515,7 @@ namespace lp {
return lia_move::undef;
}
TRACE("dio", tout << "prop_bounds:\n"; for (auto& pb: m_prop_bounds) print_prop_bound(pb, tout););
u_dependency * dep = explain_fixed_in_meta_term(m_l_matrix.m_rows[h]);
u_dependency * dep = explain_fixed_in_meta_term(meta_term);
bool change = false;
for (auto& pb: m_prop_bounds) {
pb.m_dep = lra.join_deps(pb.m_dep, dep);
@ -1542,6 +1538,15 @@ namespace lp {
return lia_move::undef;
}
// h is the entry that is ready to be moved to S
lia_move tighten_bounds_on_entry(unsigned h) {
SASSERT(entry_invariant(h));
protected_queue q;
copy_row_to_espace(h);
remove_fresh_from_espace();
return propagate_bounds_on_espace(m_sum_of_fixed[h], m_l_matrix[h]);
}
void process_fixed_in_espace() {
std_vector<unsigned> fixed_vars;
@ -1572,7 +1577,6 @@ namespace lp {
lra.print_column_info(p.var(), tout);
}
);
init_substitutions(term_to_tighten, q);
if (q.empty()) // todo: maybe still go ahead and process it?
return lia_move::undef;
@ -1608,7 +1612,15 @@ namespace lp {
if (tighten_bounds_for_non_trivial_gcd(g, j, false) != lia_move::undef) {
return lia_move::conflict;
}
return lia_move::undef;
// try more bound progagation
if (is_fixed(j)) {
m_c -= lra.get_lower_bound(j).x;
}
else {
m_espace.add(-mpq(1), lar_solver_to_local(j));
}
return propagate_bounds_on_espace(m_c, m_lspace);
}
bool should_report_branch() const {
@ -2774,7 +2786,7 @@ namespace lp {
if (min_ahk.is_one()) {
TRACE("dioph_eq", tout << "push to S:\n"; print_entry(h, tout););
SASSERT(m_new_fixed_columns.size() == 0);
if (tighten_bounds(h) == lia_move::conflict){
if (tighten_bounds_on_entry(h) == lia_move::conflict){
TRACE("dio", tout << "conflict\n";);
return lia_move::conflict;
}