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round the bound for columns and terms when it can be deduced that they are integral

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Signed-off-by: Lev Nachmanson <levnach@hotmail.com>
This commit is contained in:
Lev Nachmanson 2020-03-07 13:57:08 -08:00
parent b403b96d38
commit 6ea0bcb454
4 changed files with 43 additions and 12 deletions
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44
src/math/lp/lar_solver.cpp
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@ -1539,6 +1539,13 @@ bool lar_solver::term_is_int(const lar_term * t) const {
return true;
}
bool lar_solver::term_is_int(const vector<std::pair<mpq, unsigned int>>& coeffs) const {
for (auto const& p : coeffs)
if (! (column_is_int(p.second) && p.first.is_int()))
return false;
return true;
}
bool lar_solver::var_is_int(var_index v) const {
if (is_term(v)) {
lar_term const& t = get_term(v);
@ -1701,7 +1708,7 @@ bool lar_solver::all_vars_are_registered(const vector<std::pair<mpq, var_index>>
var_index lar_solver::add_term(const vector<std::pair<mpq, var_index>> & coeffs, unsigned ext_i) {
TRACE("lar_solver_terms", print_linear_combination_of_column_indices_only(coeffs, tout) << ", ext_i =" << ext_i << "\n";);
m_term_register.add_var(ext_i);
m_term_register.add_var(ext_i, term_is_int(coeffs));
lp_assert(all_vars_are_registered(coeffs));
if (strategy_is_undecided())
return add_term_undecided(coeffs);
@ -1774,12 +1781,33 @@ void lar_solver::activate(constraint_index ci) {
update_column_type_and_bound(c.column(), c.kind(), c.rhs(), ci);
}
mpq lar_solver::adjust_bound_for_int(lpvar j, lconstraint_kind k, const mpq& bound) {
if (!column_is_int(j))
return bound;
switch (k) {
case LT:
case LE:
return floor(bound);
case GT:
case GE:
return ceil(bound);
case EQ:
return bound;
default:
UNREACHABLE();
}
return bound;
}
constraint_index lar_solver::mk_var_bound(var_index j, lconstraint_kind kind, const mpq & right_side) {
TRACE("lar_solver", tout << "j = " << j << " " << lconstraint_kind_string(kind) << " " << right_side<< std::endl;);
constraint_index ci;
if (!is_term(j)) { // j is a var
lp_assert(bound_is_integer_for_integer_column(j, right_side));
ci = m_constraints.add_var_constraint(j, kind, right_side);
mpq rs = adjust_bound_for_int(j, kind, right_side);
lp_assert(bound_is_integer_for_integer_column(j, rs));
ci = m_constraints.add_var_constraint(j, kind, rs);
}
else {
ci = add_var_bound_on_constraint_for_term(j, kind, right_side);
@ -1821,9 +1849,11 @@ constraint_index lar_solver::add_var_bound_on_constraint_for_term(var_index j, l
unsigned adjusted_term_index = adjust_term_index(j);
// lp_assert(!term_is_int(m_terms[adjusted_term_index]) || right_side.is_int());
unsigned term_j;
lar_term const* term = m_terms[adjusted_term_index];
lar_term const* term = m_terms[adjusted_term_index];
if (m_var_register.external_is_used(j, term_j)) {
return m_constraints.add_term_constraint(term_j, term, kind, right_side);
mpq rs = adjust_bound_for_int(term_j, kind, right_side);
lp_assert(bound_is_integer_for_integer_column(term_j, rs));
return m_constraints.add_term_constraint(term_j, term, kind, rs);
}
else {
return add_constraint_from_term_and_create_new_column_row(j, term, kind, right_side);
@ -1834,7 +1864,9 @@ constraint_index lar_solver::add_constraint_from_term_and_create_new_column_row(
unsigned term_j, const lar_term* term, lconstraint_kind kind, const mpq & right_side) {
add_row_from_term_no_constraint(term, term_j);
unsigned j = A_r().column_count() - 1;
return m_constraints.add_term_constraint(j, term, kind, right_side);
mpq rs = adjust_bound_for_int(j, kind, right_side);
lp_assert(bound_is_integer_for_integer_column(j, rs));
return m_constraints.add_term_constraint(j, term, kind, rs);
}
void lar_solver::decide_on_strategy_and_adjust_initial_state() {