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sls

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2014-08-13 01:22:45 -07:00
parent cafb31ff94
commit 999db1e280
6 changed files with 92 additions and 168 deletions
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151
src/sat/sat_mus.cpp
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@ -37,7 +37,6 @@ namespace sat {
m_core.append(m_mus);
s.m_core.reset();
s.m_core.append(m_core);
m_model.reset();
}
lbool mus::operator()() {
@ -47,8 +46,7 @@ namespace sat {
reset();
literal_vector& core = m_core;
literal_vector& mus = m_mus;
core.append(s.get_core());
core.append(s.get_core());
while (!core.empty()) {
TRACE("sat",
@ -74,14 +72,9 @@ namespace sat {
case l_true: {
SASSERT(value_at(lit, s.get_model()) == l_false);
mus.push_back(lit);
if (core.empty()) {
break;
if (!core.empty()) {
// mr(); // TBD: measure
}
// sz = core.size();
// measure_mr();
// core.append(mus);
// rmr();
// core.resize(sz);
break;
}
case l_false:
@ -105,141 +98,27 @@ namespace sat {
return l_true;
}
void mus::measure_mr() {
model const& m2 = s.get_model();
if (!m_model.empty()) {
unsigned n = 0;
for (unsigned i = 0; i < m_model.size(); ++i) {
if (m2[i] != m_model[i]) ++n;
}
std::cout << "model diff: " << n << " out of " << m_model.size() << "\n";
}
m_model.reset();
m_model.append(m2);
void mus::mr() {
sls sls(s);
literal_vector tabu;
tabu.append(m_mus);
tabu.append(m_core);
bool reuse_model = false;
for (unsigned i = m_mus.size(); i < tabu.size(); ++i) {
tabu[i] = ~tabu[i];
lbool is_sat = sls(tabu.size(), tabu.c_ptr());
lbool is_sat = sls(tabu.size(), tabu.c_ptr(), reuse_model);
tabu[i] = ~tabu[i];
switch (is_sat) {
case l_true:
//m_mus.push_back(tabu[i]);
//m_core.erase(tabu[i]);
std::cout << "in core " << tabu[i] << "\n";
break;
default:
break;
if (is_sat == l_true) {
m_mus.push_back(tabu[i]);
m_core.erase(tabu[i]);
IF_VERBOSE(2, verbose_stream() << "in core " << tabu[i] << "\n";);
reuse_model = true;
}
else {
IF_VERBOSE(2, verbose_stream() << "NOT in core " << tabu[i] << "\n";);
reuse_model = false;
}
}
}
//
// TBD: eager model rotation allows rotating the same clause
// several times with respect to different models.
//
void mus::rmr() {
return;
#if 0
model& model = s.m_model;
literal lit = m_mus.back();
literal assumption_lit;
SASSERT(value_at(lit, model) == l_false);
// literal is false in current model.
unsigned sz = m_toswap.size();
find_swappable(lit);
unsigned sz1 = m_toswap.size();
for (unsigned i = sz; i < sz1; ++i) {
lit = m_toswap[i];
SASSERT(value_at(lit, model) == l_false);
model[lit.var()] = ~model[lit.var()]; // swap assignment
if (has_single_unsat(assumption_lit) && !m_mus.contains(assumption_lit)) {
m_mus.push_back(assumption_lit);
rmr();
}
model[lit.var()] = ~model[lit.var()]; // swap assignment back
}
m_toswap.resize(sz);
#endif
}
bool mus::has_single_unsat(literal& assumption_lit) {
model const& model = s.get_model();
return false;
}
//
// lit is false in model.
// find clauses where ~lit occurs, and all other literals
// are false in model.
// for each of the probed literals, determine if swapping the
// assignment falsifies a hard clause, if not, add to m_toswap.
//
void mus::find_swappable(literal lit) {
IF_VERBOSE(3, verbose_stream() << "(sat.mus swap " << lit << ")\n";);
unsigned sz = m_toswap.size();
literal lit2, lit3;
model const& model = s.get_model();
SASSERT(value_at(lit, model) == l_false);
watch_list const& wlist = s.get_wlist(lit);
watch_list::const_iterator it = wlist.begin();
watch_list::const_iterator end = wlist.end();
unsigned num_cand = 0;
for (; it != end && num_cand <= 1; ++it) {
switch (it->get_kind()) {
case watched::BINARY:
if (it->is_learned()) {
break;
}
lit2 = it->get_literal();
if (value_at(lit2, model) == l_true) {
break;
}
IF_VERBOSE(1, verbose_stream() << "(" << ~lit << " " << lit2 << ") ";);
TRACE("sat", tout << ~lit << " " << lit2 << "\n";);
++num_cand;
break;
case watched::TERNARY:
lit2 = it->get_literal1();
lit3 = it->get_literal2();
if (value_at(lit2, model) == l_true) {
break;
}
if (value_at(lit3, model) == l_true) {
break;
}
IF_VERBOSE(1, verbose_stream() << "(" << ~lit << " " << lit2 << " " << lit3 << ") ";);
++num_cand;
break;
case watched::CLAUSE: {
clause_offset cls_off = it->get_clause_offset();
clause& c = *(s.m_cls_allocator.get_clause(cls_off));
if (c.is_learned()) {
break;
}
++num_cand;
IF_VERBOSE(1, verbose_stream() << c << " ";);
TRACE("sat", tout << c << "\n";);
break;
}
case watched::EXT_CONSTRAINT:
TRACE("sat", tout << "external constraint - should avoid rmr\n";);
return;
}
}
if (num_cand > 1) {
m_toswap.resize(sz);
}
else {
IF_VERBOSE(1, verbose_stream() << "wlist size: " << num_cand << " " << m_core.size() << "\n";);
}
}
}