mirrors/z3
3
0
Fork 0
mirror of https://github.com/Z3Prover/z3 synced 2025-04-28 03:15:50 +00:00
Code Activity

Lpbounds (#4492)

Browse source 
* remove inheritance from bound propagation

Signed-off-by: Lev Nachmanson <levnach@hotmail.com>

* less inheritance

Signed-off-by: Lev Nachmanson <levnach@hotmail.com>

* less inheritance

Signed-off-by: Lev Nachmanson <levnach@hotmail.com>

* fix the build

Signed-off-by: Lev Nachmanson <levnach@hotmail.com>
This commit is contained in:
Lev Nachmanson 2020-06-02 01:00:06 -07:00 • committed by GitHub
parent 29ce22cfb1
commit 742be83503
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
9 changed files with 185 additions and 211 deletions
Download patch file Download diff file Expand all files Collapse all files

97
src/math/lp/lar_solver.h
View file

@ -41,8 +41,8 @@
#include "math/lp/conversion_helper.h"
#include "math/lp/int_solver.h"
#include "math/lp/nra_solver.h"
#include "math/lp/lp_bound_propagator.h"
#include "math/lp/lp_types.h"
#include "math/lp/lp_bound_propagator.h"
namespace lp {
@ -161,15 +161,53 @@ class lar_solver : public column_namer {
bool use_lu() const;
bool sizes_are_correct() const;
bool implied_bound_is_correctly_explained(implied_bound const & be, const vector<std::pair<mpq, unsigned>> & explanation) const;
template <typename T>
void analyze_new_bounds_on_row(
unsigned row_index,
lp_bound_propagator & bp);
lp_bound_propagator<T>& bp) {
lp_assert(!use_tableau());
unsigned j = m_mpq_lar_core_solver.m_r_basis[row_index]; // basis column for the row
bound_analyzer_on_row<indexed_vector<mpq>, lp_bound_propagator<T>>::analyze_row(
m_mpq_lar_core_solver.get_pivot_row(),
j,
zero_of_type<numeric_pair<mpq>>(),
row_index,
bp);
}
template <typename T>
void analyze_new_bounds_on_row_tableau(
unsigned row_index,
lp_bound_propagator & bp);
lp_bound_propagator<T> & bp ) {
if (A_r().m_rows[row_index].size() > settings().max_row_length_for_bound_propagation
|| row_has_a_big_num(row_index))
return;
lp_assert(use_tableau());
bound_analyzer_on_row<row_strip<mpq>, lp_bound_propagator<T>>::analyze_row(A_r().m_rows[row_index],
null_ci,
zero_of_type<numeric_pair<mpq>>(),
row_index,
bp
);
}
void substitute_basis_var_in_terms_for_row(unsigned i);
void calculate_implied_bounds_for_row(unsigned i, lp_bound_propagator & bp);
void propagate_bounds_on_a_term(const lar_term& t, lp_bound_propagator & bp, unsigned term_offset);
template <typename T>
void calculate_implied_bounds_for_row(unsigned i, lp_bound_propagator<T> & bp) {
if (use_tableau()) {
analyze_new_bounds_on_row_tableau(i, bp);
} else {
m_mpq_lar_core_solver.calculate_pivot_row(i);
substitute_basis_var_in_terms_for_row(i);
analyze_new_bounds_on_row(i, bp);
}
}
template <typename T>
void propagate_bounds_on_a_term(const lar_term& t, lp_bound_propagator<T> & bp, unsigned term_offset) {
NOT_IMPLEMENTED_YET();
}
static void clean_popped_elements(unsigned n, u_set& set);
static void shrink_inf_set_after_pop(unsigned n, u_set & set);
bool maximize_term_on_tableau(const lar_term & term,
@ -282,12 +320,55 @@ public:
void get_infeasibility_explanation(explanation &) const;
inline void backup_x() { m_backup_x = m_mpq_lar_core_solver.m_r_x; }
inline void restore_x() { m_mpq_lar_core_solver.m_r_x = m_backup_x; }
void explain_implied_bound(implied_bound & ib, lp_bound_propagator & bp);
template <typename T>
void explain_implied_bound(implied_bound & ib, lp_bound_propagator<T> & bp) {
unsigned i = ib.m_row_or_term_index;
int bound_sign = ib.m_is_lower_bound? 1: -1;
int j_sign = (ib.m_coeff_before_j_is_pos ? 1 :-1) * bound_sign;
unsigned bound_j = ib.m_j;
if (tv::is_term(bound_j)) {
bound_j = m_var_register.external_to_local(bound_j);
}
for (auto const& r : A_r().m_rows[i]) {
unsigned j = r.var();
if (j == bound_j) continue;
mpq const& a = r.coeff();
int a_sign = is_pos(a)? 1: -1;
int sign = j_sign * a_sign;
const ul_pair & ul = m_columns_to_ul_pairs[j];
auto witness = sign > 0? ul.upper_bound_witness(): ul.lower_bound_witness();
lp_assert(is_valid(witness));
bp.consume(a, witness);
}
}
// lp_assert(implied_bound_is_correctly_explained(ib, explanation)); }
constraint_index mk_var_bound(var_index j, lconstraint_kind kind, const mpq & right_side);
void activate(constraint_index ci);
void random_update(unsigned sz, var_index const * vars);
void propagate_bounds_on_terms(lp_bound_propagator & bp);
void propagate_bounds_for_touched_rows(lp_bound_propagator & bp);
template <typename T>
void propagate_bounds_on_terms(lp_bound_propagator<T> & bp) {
for (unsigned i = 0; i < m_terms.size(); i++) {
if (term_is_used_as_row(i))
continue; // this term is used a left side of a constraint,
// it was processed as a touched row if needed
propagate_bounds_on_a_term(*m_terms[i], bp, i);
}
}
template <typename T>
void propagate_bounds_for_touched_rows(lp_bound_propagator<T> & bp) {
if (!use_tableau())
return; // todo: consider to remove the restriction
for (unsigned i : m_rows_with_changed_bounds) {
calculate_implied_bounds_for_row(i, bp);
if (settings().get_cancel_flag())
return;
}
m_rows_with_changed_bounds.clear();
if (!use_tableau()) {
propagate_bounds_on_terms(bp);
}
}
bool is_fixed(column_index const& j) const { return column_is_fixed(j); }
inline column_index to_column_index(unsigned v) const { return column_index(external_to_column_index(v)); }
bool external_is_used(unsigned) const;