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Reverted to March_CU like lookahead

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This commit is contained in:
Miguel Neves 2017-10-19 19:52:56 -07:00
parent cf2512ce90
commit ba6b024ac4
2 changed files with 27 additions and 23 deletions
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45
src/sat/sat_lookahead.cpp
View file

@ -340,6 +340,13 @@ namespace sat {
}
bool lookahead::is_unsat() const {
for (unsigned idx = 0; idx < m_binary.size(); ++idx) {
literal l = to_literal(idx);
for (literal lit : m_binary[idx]) {
if (is_true(l) && is_false(lit))
return true;
}
}
// check if there is a clause whose literals are false.
// every clause is terminated by a null-literal.
for (nary* n : m_nary_clauses) {
@ -432,8 +439,21 @@ namespace sat {
bool lookahead::missed_conflict() const {
if (inconsistent()) return false;
for (literal l1 : m_trail) {
for (literal l2 : m_binary[l1.index()]) {
if (is_false(l2))
return true;
}
unsigned sz = m_ternary_count[(~l1).index()];
for (binary b : m_ternary[(~l1).index()]) {
if (sz-- == 0) break;
if ((is_false(b.m_u) && is_false(b.m_v)))
return true;
}
}
for (nary * n : m_nary_clauses) {
if (n->size() == 0) return true;
if (n->size() == 0)
return true;
}
return false;
}
@ -1144,18 +1164,6 @@ namespace sat {
SASSERT(m_trail_lim.empty() || m_trail.size() >= m_trail_lim.back());
}
void lookahead::promote(unsigned base) {
if (m_trail.empty()) return;
unsigned last_lvl = get_level(m_trail.back());
base -= last_lvl;
for (unsigned i = m_trail.size(); i > 0; ) {
literal lit = m_trail[--i];
if (is_fixed_at(lit, c_fixed_truth)) break;
SASSERT(is_fixed_at(lit, last_lvl));
m_stamp[lit.var()] += base;
}
}
//
// The current version is modeled after CDCL SAT solving data-structures.
// It borrows from the watch list data-structure. The cost tradeoffs are somewhat
@ -1496,7 +1504,7 @@ namespace sat {
sz = m_nary_count[l.index()];
for (nary* n : m_nary[l.index()]) {
if (sz-- == 0) break;
if (m_stamp[l.var()] > m_stamp[n->get_head().var()]) {
if (get_level(l) > get_level(n->get_head())) {
n->set_head(l);
}
}
@ -1692,7 +1700,6 @@ namespace sat {
num_units += do_double(lit, dl_lvl);
if (dl_lvl > level) {
base = dl_lvl;
promote(base + m_lookahead[i].m_offset);
SASSERT(get_level(m_trail.back()) == base + m_lookahead[i].m_offset);
}
unsat = inconsistent();
@ -1881,15 +1888,13 @@ namespace sat {
SASSERT(dl_no_overflow(base));
base += m_lookahead.size();
unsigned dl_truth = base + m_lookahead.size() * m_config.m_dl_max_iterations;
promote(dl_truth);
scoped_level _sl(*this, dl_truth);
SASSERT(get_level(m_trail.back()) == dl_truth);
SASSERT(is_fixed(l));
IF_VERBOSE(2, verbose_stream() << "double: " << l << " depth: " << m_trail_lim.size() << "\n";);
//lookahead_backtrack();
//assign(l);
//propagate();
//SASSERT(!inconsistent());
lookahead_backtrack();
assign(l);
propagate();
unsigned old_sz = m_trail.size();
bool change = true;
literal last_changed = null_literal;

5
src/sat/sat_lookahead.h
View file

@ -90,7 +90,7 @@ namespace sat {
m_min_cutoff = 30;
m_preselect = false;
m_level_cand = 600;
m_delta_rho = (double)0.85;
m_delta_rho = (double)0.7;
m_dl_max_iterations = 2;
m_tc1_limit = 10000000;
m_reward_type = ternary_reward;
@ -246,7 +246,7 @@ namespace sat {
inline bool is_true(literal l) const { return is_true_at(l, m_level); }
inline void set_true(literal l) { m_stamp[l.var()] = m_level + l.sign(); }
inline void set_undef(literal l) { m_stamp[l.var()] = 0; }
inline unsigned get_level(literal l) { return m_stamp[l.var()] & UINT_MAX - 1; }
inline unsigned get_level(literal l) const { return m_stamp[l.var()] & UINT_MAX - 1; }
void set_level(literal d, literal s) { m_stamp[d.var()] = (m_stamp[s.var()] & ~0x1) + d.sign(); }
lbool value(literal l) const { return is_undef(l) ? l_undef : is_true(l) ? l_true : l_false; }
@ -480,7 +480,6 @@ namespace sat {
unsigned push_lookahead1(literal lit, unsigned level);
void pop_lookahead1(literal lit, unsigned num_units);
void lookahead_backtrack();
void promote(unsigned base);
double mix_diff(double l, double r) const;
clause const& get_clause(watch_list::iterator it) const;
bool is_nary_propagation(clause const& c, literal l) const;