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fix bugs in scc_tr

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2018-03-25 14:55:42 -07:00
parent bfc0b214ab
commit a79400a01b
7 changed files with 83 additions and 41 deletions
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64
src/sat/sat_big.cpp
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@ -164,8 +164,19 @@ namespace sat {
DEBUG_CODE(for (unsigned i = 0; i < num_lits; ++i) { VERIFY(m_left[i] < m_right[i]);});
}
unsigned big::reduce_tr(solver& s) {
// svector<std::pair<literal, literal>> big::s_del_bin;
bool big::in_del(literal u, literal v) const {
if (u.index() > v.index()) std::swap(u, v);
return m_del_bin.contains(std::make_pair(u, v));
}
void big::add_del(literal u, literal v) {
if (u.index() > v.index()) std::swap(u, v);
m_del_bin.push_back(std::make_pair(u, v));
}
unsigned big::reduce_tr(solver& s) {
unsigned num_lits = s.num_vars() * 2;
unsigned idx = 0;
unsigned elim = 0;
@ -182,7 +193,8 @@ namespace sat {
literal v = w.get_literal();
if (u != get_parent(v) && safe_reach(u, v)) {
++elim;
m_del_bin.push_back(std::make_pair(~u, v));
add_del(~u, v);
// IF_VERBOSE(1, verbose_stream() << "remove " << u << " -> " << v << "\n");
if (find_binary_watch(wlist, ~v)) {
IF_VERBOSE(10, verbose_stream() << "binary: " << ~u << "\n");
s.assign(~u, justification());
@ -197,6 +209,23 @@ namespace sat {
}
wlist.set_end(itprev);
}
#if 0
s_del_bin.append(m_del_bin);
IF_VERBOSE(1,
display(verbose_stream() << "Learned: " << learned() << ":");
verbose_stream() << "del-bin\n";
for (auto p : m_del_bin) {
verbose_stream() << p.first << " " << p.second << "\n";
if (safe_reach(~p.first, p.second)) {
display_path(verbose_stream(), ~p.first, p.second) << " " << "\n";
}
else {
display_path(verbose_stream(), ~p.second, p.first) << " " << "\n";
}
}
);
#endif
s.propagate(false);
return elim;
}
@ -205,8 +234,7 @@ namespace sat {
if (!reaches(u, v)) return false;
while (u != v) {
literal w = next(u, v);
if (m_del_bin.contains(std::make_pair(~u, w)) ||
m_del_bin.contains(std::make_pair(~w, u))) {
if (in_del(~u, w)) {
return false;
}
u = w;
@ -216,11 +244,27 @@ namespace sat {
literal big::next(literal u, literal v) const {
SASSERT(reaches(u, v));
literal result = null_literal;
int left = m_right[u.index()];
// identify the path from the reachability graph
for (literal w : m_dag[u.index()]) {
if (reaches(u, w) && (w == v || reaches(w, v))) return w;
if (reaches(u, w) &&
(w == v || reaches(w, v)) &&
m_left[w.index()] < left) {
left = m_left[w.index()];
result = w;
}
}
UNREACHABLE();
return null_literal;
SASSERT(result != null_literal);
return result;
}
std::ostream& big::display_path(std::ostream& out, literal u, literal v) const {
while (u != v) {
out << u << " -> ";
u = next(u, v);
}
return out << v;
}
void big::display(std::ostream& out) const {
@ -228,6 +272,12 @@ namespace sat {
for (auto& next : m_dag) {
if (!next.empty()) {
out << to_literal(idx) << " : " << m_left[idx] << ":" << m_right[idx] << " -> " << next << "\n";
#if 0
for (literal n : next) {
out << n << "[" << m_left[n.index()] << ":" << m_right[n.index()] << "] ";
}
out << "\n";
#endif
}
++idx;
}