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fix #2949 fix #2955 experiment with cut selection

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2020-02-08 10:34:14 -08:00
parent 140926e7c0
commit f29b455611
7 changed files with 74 additions and 41 deletions
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55
src/math/lp/int_solver.cpp
View file

@ -37,6 +37,55 @@ bool int_solver::has_inf_int() const {
return m_lar_solver->has_inf_int();
}
int int_solver::find_gomory_cut_column() {
int result = -1;
unsigned n = 0;
bool boxed = false;
unsigned min_row_size = UINT_MAX;
mpq min_range;
// Prefer smaller row size
#if 0
// Prefer boxed to non-boxed
// Prefer smaller ranges
#endif
for (unsigned j : m_lar_solver->r_basis()) {
if (!column_is_int_inf(j))
continue;
const row_strip<mpq>& row = m_lar_solver->get_row(row_of_basic_column(j));
if (!is_gomory_cut_target(row))
continue;
#if 1
if (is_boxed(j) && (min_row_size == UINT_MAX || 4*row.size() < 5*min_row_size)) {
lar_core_solver & lcs = m_lar_solver->m_mpq_lar_core_solver;
auto new_range = lcs.m_r_upper_bounds()[j].x - lcs.m_r_lower_bounds()[j].x;
if (!boxed) {
result = j;
n = 1;
min_row_size = row.size();
boxed = true;
min_range = new_range;
continue;
}
if (min_range > 2*new_range || ((5*min_range > 4*new_range && (random() % (++n)) == 0))) {
result = j;
n = 1;
min_row_size = row.size();
min_range = std::min(min_range, new_range);
continue;
}
}
#endif
if (min_row_size == UINT_MAX || (4*row.size() < 5*min_row_size && random() % (++n) == 0)) {
result = j;
n = 1;
min_row_size = std::min(min_row_size, row.size());
}
}
return result;
}
int int_solver::find_inf_int_base_column() {
unsigned inf_int_count = 0;
int j = find_inf_int_boxed_base_column_with_smallest_range(inf_int_count);
@ -304,7 +353,8 @@ lia_move int_solver::gomory_cut() {
lp_assert(st == lp_status::FEASIBLE || st == lp_status::OPTIMAL);
}
int j = find_inf_int_base_column();
// int j = find_inf_int_base_column();
int j = find_gomory_cut_column();
if (j == -1) {
j = find_inf_int_nbasis_column();
return j == -1? lia_move::sat : create_branch_on_column(j);
@ -1019,7 +1069,8 @@ lia_move int_solver::create_branch_on_column(int j) {
if (is_free(j)) {
m_upper = random() % 2;
m_k = mpq(0);
} else {
}
else {
m_upper = left_branch_is_more_narrow_than_right(j);
m_k = m_upper? floor(get_value(j)) : ceil(get_value(j));
}

1
src/math/lp/int_solver.h
View file

@ -107,6 +107,7 @@ private:
lia_move branch_or_sat();
int find_any_inf_int_column_basis_first();
int find_inf_int_base_column();
int find_gomory_cut_column();
int find_inf_int_boxed_base_column_with_smallest_range(unsigned&);
int get_kth_inf_int(unsigned) const;
lp_settings& settings();

9
src/math/lp/lar_constraints.h
View file

@ -158,10 +158,6 @@ public:
}
void pop(unsigned k) {
m_constraint_count.pop(k);
for (unsigned i = m_constraints.size(); i-- > m_constraint_count; )
m_constraints[i]->~lar_base_constraint();
m_constraints.shrink(m_constraint_count);
#if 1
m_active_lim.pop(k);
for (unsigned i = m_active.size(); i-- > m_active_lim; ) {
@ -169,6 +165,11 @@ public:
}
m_active.shrink(m_active_lim);
#endif
m_constraint_count.pop(k);
for (unsigned i = m_constraints.size(); i-- > m_constraint_count; )
m_constraints[i]->~lar_base_constraint();
m_constraints.shrink(m_constraint_count);
m_region.pop_scope(k);
}

16
src/smt/smt_context.cpp
View file

@ -1861,13 +1861,15 @@ namespace smt {
break;
}
}
if (m_lit_occs[l.index()] == 0) {
is_pos = false;
break;
}
if (m_lit_occs[(~l).index()] == 0) {
is_pos = true;
break;
if (track_occs()) {
if (m_lit_occs[l.index()] == 0) {
is_pos = false;
break;
}
if (m_lit_occs[(~l).index()] == 0) {
is_pos = true;
break;
}
}
is_pos = m_phase_default;
break;

2
src/smt/smt_context.h
View file

@ -839,7 +839,7 @@ namespace smt {
void mk_ite_cnstr(app * n);
bool track_occs() const { return m_fparams.m_phase_selection == PS_THEORY; }
bool track_occs() const { return m_fparams.m_phase_selection == PS_OCCURRENCE; }
void dec_ref(literal l);

29
src/smt/theory_lra.cpp
View file

@ -1864,28 +1864,6 @@ public:
return atom;
}
// bool make_sure_all_vars_have_bounds() {
// if (!has_int()) {
// return true;
// }
// unsigned nv = std::min(th.get_num_vars(), m_theory_var2var_index.size());
// bool all_bounded = true;
// for (unsigned v = 0; v < nv; ++v) {
// lpvar vi = m_theory_var2var_index[v];
// if (vi == UINT_MAX)
// continue;
// if (!lp().is_term(vi) && !var_has_bound(vi, true) && !var_has_bound(vi, false)) {
// lp::lar_term term;
// term.add_coeff_var(rational::one(), vi);
// app_ref b = mk_bound(term, rational::zero(), true);
// TRACE("arith", tout << "added bound " << b << "\n";);
// IF_VERBOSE(2, verbose_stream() << "bound: " << b << "\n");
// all_bounded = false;
// }
// }
// return all_bounded;
// }
/**
* n = (div p q)
@ -1919,7 +1897,6 @@ public:
if (m_idiv_terms.empty()) {
return true;
}
// init_variable_values();
bool all_divs_valid = true;
for (expr* n : m_idiv_terms) {
expr* p = nullptr, *q = nullptr;
@ -1927,10 +1904,9 @@ public:
theory_var v = mk_var(n);
theory_var v1 = mk_var(p);
lp::impq r1 = get_ivalue(v1);
SASSERT(r1.y.is_zero());
rational r2;
if (!r1.x.is_int() || r1.x.is_neg()) {
if (!r1.x.is_int() || r1.x.is_neg() || !r1.y.is_zero()) {
// TBD
// r1 = 223/4, r2 = 2, r = 219/8
// take ceil(r1), floor(r1), ceil(r2), floor(r2), for floor(r2) > 0
@ -1946,8 +1922,7 @@ public:
continue;
}
lp::impq val_v = get_ivalue(v);
SASSERT(val_v.y.is_zero());
if (val_v.x == div(r1.x, r2)) continue;
if (val_v.y.is_zero() && val_v.x == div(r1.x, r2)) continue;
TRACE("arith", tout << get_value(v) << " != " << r1 << " div " << r2 << "\n";);
rational div_r = div(r1.x, r2);

3
src/util/mpz.cpp
View file

@ -1680,6 +1680,9 @@ double mpz_manager<SYNCH>::get_double(mpz const & a) const {
else
d *= static_cast<double>(UINT_MAX); // 32-bit version
}
if (!(r >= 0.0)) {
r = static_cast<double>(UINT64_MAX); // some large number
}
return a.m_val < 0 ? -r : r;
#else
return mpz_get_d(*a.m_ptr);