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fixing optimizaiton bug

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2013-12-18 08:43:07 +02:00
parent 22166d0760
commit eb1b578bfb
3 changed files with 49 additions and 36 deletions
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7
src/smt/theory_arith.h
View file

@ -434,7 +434,6 @@ namespace smt {
bool m_eager_gcd; // true if gcd should be applied at every add_row
unsigned m_final_check_idx;
u_map<uint_set> m_objective_theory_vars;
// backtracking
svector<bound_trail> m_bound_trail;
@ -857,11 +856,13 @@ namespace smt {
void add_tmp_row(row & r1, numeral const & coeff, row const & r2);
theory_var pick_var_to_leave(theory_var x_j, bool inc, numeral & a_ij, inf_numeral & gain);
bool is_safe_to_leave(theory_var x);
void move_to_bound(theory_var x_i, bool inc);
template<bool invert>
void add_tmp_row_entry(row & r, numeral const & coeff, theory_var v);
bool max_min(theory_var v, bool max);
bool max_min(row & r, bool max);
enum max_min_t { UNBOUNDED, AT_BOUND, OPTIMIZED, BEST_EFFORT};
max_min_t max_min(theory_var v, bool max);
max_min_t max_min(row & r, bool max);
bool max_min(svector<theory_var> const & vars);
// -----------------------------------

77
src/smt/theory_arith_aux.h
View file

@ -927,6 +927,26 @@ namespace smt {
*/
template<typename Ext>
bool theory_arith<Ext>::is_safe_to_leave(theory_var x) {
column & c = m_columns[x];
typename svector<col_entry>::iterator it = c.begin_entries();
typename svector<col_entry>::iterator end = c.end_entries();
for (; it != end; ++it) {
if (it->is_dead()) continue;
row const & r = m_rows[it->m_row_id];
theory_var s = r.get_base_var();
numeral const & coeff = r[it->m_row_idx].m_coeff;
bool is_unsafe = (s != null_theory_var && is_int(s) && !coeff.is_int());
TRACE("opt", tout << "is v" << x << " safe to leave for v" << s << "? " << (is_unsafe?"no":"yes") << "\n";
display_row(tout, r, true););
if (is_unsafe) return false;
}
return true;
}
template<typename Ext>
theory_var theory_arith<Ext>::pick_var_to_leave(theory_var x_j, bool inc, numeral & a_ij, inf_numeral & gain) {
TRACE("opt", tout << "selecting variable to replace v" << x_j << ", inc: " << inc << "\n";);
@ -986,6 +1006,9 @@ namespace smt {
}
}
}
else if (m_util.is_to_real(n, x) || m_util.is_to_int(n, x)) {
return get_theory_vars(x, vars);
}
else if (m_util.is_mul(n, x, y) && m_util.is_numeral(x, r)) {
return get_theory_vars(y, vars);
}
@ -1019,10 +1042,6 @@ namespace smt {
template<typename Ext>
theory_var theory_arith<Ext>::add_objective(app* term) {
theory_var v = internalize_term_core(term);
uint_set vars;
if (get_theory_vars(term, vars)) {
m_objective_theory_vars.insert(v, vars);
}
TRACE("opt", tout << mk_pp(term, get_manager()) << " |-> v" << v << "\n";);
TRACE("opt", tout << "data-size: " << m_data.size() << "\n";);
SASSERT(!is_quasi_base(v));
@ -1032,22 +1051,12 @@ namespace smt {
template<typename Ext>
inf_eps_rational<inf_rational> theory_arith<Ext>::maximize(theory_var v) {
TRACE("opt", tout << "data-size: " << m_data.size() << "\n";);
bool r = max_min(v, true);
if (r || at_upper(v)) {
if (m_objective_theory_vars.contains(v)) {
// FIXME: put this block inside verbose code
uint_set & vars = m_objective_theory_vars[v];
uint_set::iterator it = vars.begin(), end = vars.end();
ast_manager& m = get_manager();
IF_VERBOSE(1,
verbose_stream() << "Optimal assigment:" << std::endl;
for (; it != end; ++it) {
verbose_stream() << mk_pp(get_enode(*it)->get_owner(), m) << " |-> " << get_value(*it) << std::endl;
};);
}
return inf_eps_rational<inf_rational>(get_value(v));
max_min_t r = max_min(v, true);
if (r == UNBOUNDED) {
return inf_eps_rational<inf_rational>::infinity();
}
return inf_eps_rational<inf_rational>::infinity();
return inf_eps_rational<inf_rational>(get_value(v));
}
/**
@ -1092,7 +1101,6 @@ namespace smt {
*/
template<typename Ext>
expr* theory_arith<Ext>::mk_ge(filter_model_converter& fm, theory_var v, inf_numeral const& val) {
SASSERT(m_objective_theory_vars.contains(v));
ast_manager& m = get_manager();
context& ctx = get_context();
std::ostringstream strm;
@ -1262,9 +1270,10 @@ namespace smt {
Return true if succeeded.
*/
template<typename Ext>
bool theory_arith<Ext>::max_min(row & r, bool max) {
typename theory_arith<Ext>::max_min_t theory_arith<Ext>::max_min(row & r, bool max) {
TRACE("max_min", tout << "max_min...\n";);
m_stats.m_max_min++;
bool skipped_row = false;
SASSERT(valid_row_assignment());
SASSERT(satisfy_bounds());
@ -1292,6 +1301,10 @@ namespace smt {
bool curr_inc = curr_coeff.is_pos() ? max : !max;
if ((curr_inc && at_upper(curr_x_j)) || (!curr_inc && at_lower(curr_x_j)))
continue; // variable cannot be used for max/min.
if (!is_safe_to_leave(curr_x_j)) {
skipped_row = true;
continue;
}
theory_var curr_x_i = pick_var_to_leave(curr_x_j, curr_inc, curr_a_ij, curr_gain);
if (curr_x_i == null_theory_var) {
// we can increase/decrease curr_x_j as much as we want.
@ -1325,7 +1338,7 @@ namespace smt {
TRACE("opt", tout << "row is " << (max ? "maximized" : "minimized") << "\n";);
SASSERT(valid_row_assignment());
SASSERT(satisfy_bounds());
return true;
return skipped_row?BEST_EFFORT:OPTIMIZED;
}
if (x_i == null_theory_var) {
@ -1344,7 +1357,7 @@ namespace smt {
SASSERT(satisfy_bounds());
continue;
}
return false; // unbounded.
return UNBOUNDED;
}
if (!is_fixed(x_j) && is_bounded(x_j) && (upper_bound(x_j) - lower_bound(x_j) <= gain)) {
@ -1471,13 +1484,13 @@ namespace smt {
\brief Maximize/Minimize the given variable. The bounds of v are update if procedure succeeds.
*/
template<typename Ext>
bool theory_arith<Ext>::max_min(theory_var v, bool max) {
typename theory_arith<Ext>::max_min_t theory_arith<Ext>::max_min(theory_var v, bool max) {
TRACE("opt", tout << (max ? "maximizing" : "minimizing") << " v" << v << "...\n";);
SASSERT(valid_row_assignment());
SASSERT(satisfy_bounds());
SASSERT(!is_quasi_base(v));
if ((max && at_upper(v)) || (!max && at_lower(v)))
return false; // nothing to be done...
return AT_BOUND; // nothing to be done...
m_tmp_row.reset();
if (is_non_base(v)) {
add_tmp_row_entry<false>(m_tmp_row, numeral(1), v);
@ -1491,15 +1504,15 @@ namespace smt {
add_tmp_row_entry<true>(m_tmp_row, it->m_coeff, it->m_var);
}
}
if (max_min(m_tmp_row, max)) {
max_min_t r = max_min(m_tmp_row, max);
if (r == OPTIMIZED) {
TRACE("opt", tout << "v" << v << " " << (max ? "max" : "min") << " value is: " << get_value(v) << "\n";
display_row(tout, m_tmp_row, true); display_row_info(tout, m_tmp_row););
mk_bound_from_row(v, get_value(v), max ? B_UPPER : B_LOWER, m_tmp_row);
return true;
}
return false;
return r;
}
/**
@ -1512,9 +1525,9 @@ namespace smt {
svector<theory_var>::const_iterator it = vars.begin();
svector<theory_var>::const_iterator end = vars.end();
for (; it != end; ++it) {
if (max_min(*it, true))
if (max_min(*it, true) == OPTIMIZED)
succ = true;
if (max_min(*it, false))
if (max_min(*it, false) == OPTIMIZED)
succ = true;
}
if (succ) {
@ -1688,9 +1701,9 @@ namespace smt {
m_tmp_lit_set.reset();
m_tmp_eq_set.reset();
if (max_min(m_tmp_row, true) &&
if ((OPTIMIZED == max_min(m_tmp_row, true)) &&
is_zero_row(m_tmp_row, true, m_tmp_acc_lits, m_tmp_acc_eqs, m_tmp_lit_set, m_tmp_eq_set) &&
max_min(m_tmp_row, false) &&
(OPTIMIZED == max_min(m_tmp_row, false)) &&
is_zero_row(m_tmp_row, false, m_tmp_acc_lits, m_tmp_acc_eqs, m_tmp_lit_set, m_tmp_eq_set)) {
// v1 == v2
TRACE("imply_eq", tout << "found new implied equality:\n";

1
src/smt/theory_arith_core.h
View file

@ -1237,7 +1237,6 @@ namespace smt {
m_nl_rounds = 0;
m_nl_gb_exhausted = false;
m_nl_strategy_idx = 0;
m_objective_theory_vars .reset();
theory::reset_eh();
}