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fix autarky detection

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2017-03-31 13:16:04 -07:00
parent 6571aad440
commit c0188a7ec0
3 changed files with 87 additions and 26 deletions
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31
src/sat/sat_local_search.cpp
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@ -137,6 +137,17 @@ namespace sat {
}
void local_search::reinit() {
// the following methods does NOT converge for pseudo-boolean
// can try other way to define "worse" and "better"
// the current best noise is below 1000
if (best_unsat_rate >= last_best_unsat_rate) {
// worse
noise = noise - noise * 2 * noise_delta;
}
else {
// better
noise = noise + (10000 - noise) * noise_delta;
}
for (unsigned i = 0; i < m_constraints.size(); ++i) {
constraint& c = m_constraints[i];
c.m_slack = c.m_k;
@ -370,11 +381,16 @@ namespace sat {
if (tries % 10 == 0 || m_unsat_stack.empty()) { \
IF_VERBOSE(1, verbose_stream() << "(sat-local-search" \
<< " :flips " << flips \
<< " :unsat " << m_unsat_stack.size() \
<< " :noise " << noise \
<< " :unsat " << /*m_unsat_stack.size()*/ best_unsat \
<< " :time " << (timer.get_seconds() < 0.001 ? 0.0 : timer.get_seconds()) << ")\n";); \
}
void local_search::walksat() {
best_unsat_rate = 1;
last_best_unsat_rate = 1;
reinit();
timer timer;
timer.start();
@ -382,12 +398,17 @@ namespace sat {
PROGRESS(tries, total_flips);
for (tries = 1; !m_unsat_stack.empty() && m_limit.inc(); ++tries) {
if (m_unsat_stack.size() < best_unsat) {
best_unsat = m_unsat_stack.size();
last_best_unsat_rate = best_unsat_rate;
best_unsat_rate = (double)m_unsat_stack.size() / num_constraints();
}
for (step = 0; step < m_max_steps && !m_unsat_stack.empty(); ++step) {
pick_flip_walksat();
}
total_flips += step;
PROGRESS(tries, total_flips);
if (m_par && tries % 30 == 0) {
if (m_par && tries % 20 == 0) {
m_par->get_phase(*this);
reinit();
}
@ -483,7 +504,9 @@ namespace sat {
unsigned num_unsat = m_unsat_stack.size();
constraint const& c = m_constraints[m_unsat_stack[m_rand() % m_unsat_stack.size()]];
SASSERT(c.m_k < constraint_value(c));
if (m_rand() % 100 < 98) {
// TBD: dynamic noise strategy
//if (m_rand() % 100 < 98) {
if (m_rand() % 10000 >= noise) {
// take this branch with 98% probability.
// find the first one, to fast break the rest
unsigned best_bsb = 0;
@ -533,7 +556,7 @@ namespace sat {
best_var = v;
n = 1;
}
else {// if (bb == best_bb)
else {// if (bsb == best_bb)
++n;
if (m_rand() % n == 0) {
best_var = v;