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fix local search initialization of units, encode offset in clauses

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2018-04-28 22:26:01 +02:00
parent 38888b5e5c
commit 2f025f52c0
6 changed files with 47 additions and 18 deletions
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27
src/sat/sat_local_search.cpp
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@ -79,11 +79,13 @@ namespace sat {
void local_search::init_cur_solution() {
for (var_info& vi : m_vars) {
// use bias with a small probability
if (m_rand() % 10 < 5 || m_config.phase_sticky()) {
vi.m_value = ((unsigned)(m_rand() % 100) < vi.m_bias);
}
else {
vi.m_value = (m_rand() % 2) == 0;
if (!vi.m_unit) {
if (m_rand() % 10 < 5 || m_config.phase_sticky()) {
vi.m_value = ((unsigned)(m_rand() % 100) < vi.m_bias);
}
else {
vi.m_value = (m_rand() % 2) == 0;
}
}
}
}
@ -149,7 +151,7 @@ namespace sat {
void local_search::reinit() {
IF_VERBOSE(0, verbose_stream() << "(sat-local-search reinit)\n";);
IF_VERBOSE(1, verbose_stream() << "(sat-local-search reinit)\n";);
if (true || !m_is_pb) {
//
// the following methods does NOT converge for pseudo-boolean
@ -216,13 +218,15 @@ namespace sat {
for (unsigned i = 0; i < m_prop_queue.size() && i < m_vars.size(); ++i) {
literal lit2 = m_prop_queue[i];
if (!is_true(lit2)) {
if (is_unit(lit2)) return false;
if (is_unit(lit2)) {
return false;
}
flip_walksat(lit2.var());
add_propagation(lit2);
}
}
if (m_prop_queue.size() >= m_vars.size()) {
IF_VERBOSE(0, verbose_stream() << "failed literal\n");
IF_VERBOSE(0, verbose_stream() << "propagation loop\n");
return false;
}
if (unit) {
@ -328,6 +332,7 @@ namespace sat {
return;
}
if (k == 1 && sz == 2) {
// IF_VERBOSE(0, verbose_stream() << "bin: " << ~c[0] << " + " << ~c[1] << " <= 1\n");
for (unsigned i = 0; i < 2; ++i) {
literal t(c[i]), s(c[1-i]);
m_vars.reserve(t.var() + 1);
@ -750,11 +755,12 @@ namespace sat {
IF_VERBOSE(1, verbose_stream() << "(sat.local_search :unsat)\n");
return;
}
if (is_unit(best_var)) {
goto reflip;
}
flip_walksat(best_var);
literal lit(best_var, !cur_solution(best_var));
if (!propagate(lit)) {
IF_VERBOSE(0, verbose_stream() << "failed literal " << lit << "\n");
if (is_true(lit)) {
flip_walksat(best_var);
}
@ -774,6 +780,7 @@ namespace sat {
}
void local_search::flip_walksat(bool_var flipvar) {
VERIFY(!is_unit(flipvar));
m_vars[flipvar].m_value = !cur_solution(flipvar);
bool flip_is_true = cur_solution(flipvar);