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fixes

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2017-11-07 17:16:36 -08:00
parent 16555d4886
commit 2746528aab
19 changed files with 186 additions and 106 deletions
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141
src/sat/sat_asymm_branch.cpp
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@ -57,7 +57,7 @@ namespace sat {
};
void asymm_branch::operator()(bool force) {
if (!m_asymm_branch)
if (!m_asymm_branch && !m_asymm_branch_all)
return;
s.propagate(false); // must propagate, since it uses s.push()
if (s.m_inconsistent)
@ -92,7 +92,6 @@ namespace sat {
}
s.checkpoint();
clause & c = *(*it);
m_counter -= c.size();
if (!process(c))
continue; // clause was removed
*it2 = *it;
@ -114,57 +113,52 @@ namespace sat {
CASSERT("asymm_branch", s.check_invariant());
}
bool asymm_branch::process(clause & c) {
if (c.is_blocked()) return true;
TRACE("asymm_branch_detail", tout << "processing: " << c << "\n";);
SASSERT(s.scope_lvl() == 0);
SASSERT(s.m_qhead == s.m_trail.size());
#ifdef Z3DEBUG
unsigned trail_sz = s.m_trail.size();
#endif
SASSERT(!s.inconsistent());
bool asymm_branch::process_all(clause & c) {
// try asymmetric branching on all literals in clause.
// clause must not be used for propagation
scoped_detach scoped_d(s, c);
unsigned sz = c.size();
SASSERT(sz > 0);
unsigned i;
// check if the clause is already satisfied
for (i = 0; i < sz; i++) {
if (s.value(c[i]) == l_true) {
s.detach_clause(c);
s.del_clause(c);
return false;
}
unsigned i = 0, new_sz = sz;
bool found = false;
for (; i < sz; i++) {
found = flip_literal_at(c, i, new_sz);
if (found) break;
}
// try asymmetric branching
// clause must not be used for propagation
solver::scoped_detach scoped_d(s, c);
return !found || cleanup(scoped_d, c, i, new_sz);
}
bool asymm_branch::propagate_literal(clause const& c, literal l) {
m_counter -= c.size();
SASSERT(!s.inconsistent());
TRACE("asymm_branch_detail", tout << "assigning: " << l << "\n";);
s.assign(l, justification());
s.propagate_core(false); // must not use propagate(), since check_missed_propagation may fail for c
return s.inconsistent();
}
bool asymm_branch::flip_literal_at(clause const& c, unsigned flip_index, unsigned& new_sz) {
bool found_conflict = false;
unsigned i = 0, sz = c.size();
s.push();
for (i = 0; i < sz - 1; i++) {
literal l = c[i];
SASSERT(!s.inconsistent());
TRACE("asymm_branch_detail", tout << "assigning: " << ~l << "\n";);
s.assign(~l, justification());
s.propagate_core(false); // must not use propagate(), since check_missed_propagation may fail for c
if (s.inconsistent())
break;
for (i = 0; !found_conflict && i < sz; i++) {
if (i == flip_index) continue;
found_conflict = propagate_literal(c, ~c[i]);
}
if (!found_conflict) {
SASSERT(sz == i);
found_conflict = propagate_literal(c, c[flip_index]);
}
s.pop(1);
SASSERT(!s.inconsistent());
SASSERT(s.scope_lvl() == 0);
SASSERT(trail_sz == s.m_trail.size());
SASSERT(s.m_qhead == s.m_trail.size());
if (i == sz - 1) {
// clause size can't be reduced.
return true;
}
// clause can be reduced
unsigned new_sz = i+1;
SASSERT(new_sz >= 1);
SASSERT(new_sz < sz);
TRACE("asymm_branch", tout << c << "\nnew_size: " << new_sz << "\n";
for (unsigned i = 0; i < c.size(); i++) tout << static_cast<int>(s.value(c[i])) << " "; tout << "\n";);
// cleanup reduced clause
new_sz = i;
return found_conflict;
}
bool asymm_branch::cleanup(scoped_detach& scoped_d, clause& c, unsigned skip_idx, unsigned new_sz) {
unsigned j = 0;
for (i = 0; i < new_sz; i++) {
for (unsigned i = 0; i < new_sz; i++) {
if (skip_idx == i) continue;
literal l = c[i];
switch (s.value(l)) {
case l_undef:
@ -181,7 +175,7 @@ namespace sat {
}
}
new_sz = j;
m_elim_literals += sz - new_sz;
m_elim_literals += c.size() - new_sz;
switch(new_sz) {
case 0:
s.set_conflict(justification());
@ -208,12 +202,65 @@ namespace sat {
return true;
}
}
bool asymm_branch::process(clause & c) {
if (c.is_blocked()) return true;
TRACE("asymm_branch_detail", tout << "processing: " << c << "\n";);
SASSERT(s.scope_lvl() == 0);
SASSERT(s.m_qhead == s.m_trail.size());
SASSERT(!s.inconsistent());
#ifdef Z3DEBUG
unsigned trail_sz = s.m_trail.size();
#endif
unsigned sz = c.size();
SASSERT(sz > 0);
unsigned i;
// check if the clause is already satisfied
for (i = 0; i < sz; i++) {
if (s.value(c[i]) == l_true) {
s.detach_clause(c);
s.del_clause(c);
return false;
}
}
if (m_asymm_branch_all) return process_all(c);
m_counter -= c.size();
// try asymmetric branching
// clause must not be used for propagation
scoped_detach scoped_d(s, c);
s.push();
bool found_conflict = false;
for (i = 0; i < sz - 1 && !found_conflict; i++) {
found_conflict = propagate_literal(c, ~c[i]);
}
s.pop(1);
SASSERT(!s.inconsistent());
SASSERT(s.scope_lvl() == 0);
SASSERT(trail_sz == s.m_trail.size());
SASSERT(s.m_qhead == s.m_trail.size());
SASSERT(found_conflict == (i != sz - 1));
if (!found_conflict) {
// clause size can't be reduced.
return true;
}
// clause can be reduced
unsigned new_sz = i+1;
SASSERT(new_sz >= 1);
SASSERT(new_sz < sz);
TRACE("asymm_branch", tout << c << "\nnew_size: " << new_sz << "\n";
for (unsigned i = 0; i < c.size(); i++) tout << static_cast<int>(s.value(c[i])) << " "; tout << "\n";);
// cleanup and attach reduced clause
return cleanup(scoped_d, c, sz, new_sz);
}
void asymm_branch::updt_params(params_ref const & _p) {
sat_asymm_branch_params p(_p);
m_asymm_branch = p.asymm_branch();
m_asymm_branch_rounds = p.asymm_branch_rounds();
m_asymm_branch_limit = p.asymm_branch_limit();
m_asymm_branch_all = p.asymm_branch_all();
if (m_asymm_branch_limit > INT_MAX)
m_asymm_branch_limit = INT_MAX;
}