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Find AND and XOR clauses.

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Mathias Soeken 2020-02-27 19:04:19 +01:00 • committed by Nikolaj Bjorner
parent 0713d1cdb1
commit 595fea7434
2 changed files with 81 additions and 0 deletions
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75
src/sat/sat_npn3_finder.cpp
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@ -65,6 +65,8 @@ namespace sat {
find_mux(clauses);
find_maj(clauses);
find_orand(clauses);
find_and(clauses);
find_xor(clauses);
find_andxor(clauses);
find_xorand(clauses);
find_onehot(clauses);
@ -308,6 +310,79 @@ namespace sat {
find_npn3(clauses, m_on_orand, try_orand);
}
void npn3_finder::find_xor(clause_vector& clauses) {
if (!m_on_xor) return;
binary_hash_table_t binaries;
ternary_hash_table_t ternaries;
quaternary_hash_table_t quaternaries;
process_more_clauses(clauses, binaries, ternaries, quaternaries);
const auto try_xor = [&](literal w, literal x, literal y, literal z, clause &c) {
clause *c1, *c2, *c3, *c4, *c5, *c6, *c7;
if (!has_quaternary(quaternaries, ternaries, ~x, ~y, z, w, c1)) return false;
if (!has_quaternary(quaternaries, ternaries, ~x, y, ~z, w, c2)) return false;
if (!has_quaternary(quaternaries, ternaries, ~x, y, z, ~w, c3)) return false;
if (!has_quaternary(quaternaries, ternaries, ~x, ~y, ~z, ~w, c4)) return false;
if (!has_quaternary(quaternaries, ternaries, x, y, ~z, ~w, c5)) return false;
if (!has_quaternary(quaternaries, ternaries, x, ~y, z, ~w, c6)) return false;
if (!has_quaternary(quaternaries, ternaries, x, ~y, ~z, w, c7)) return false;
c.mark_used();
if (c1) c1->mark_used();
if (c2) c2->mark_used();
if (c3) c3->mark_used();
if (c4) c4->mark_used();
if (c5) c5->mark_used();
if (c6) c6->mark_used();
if (c7) c7->mark_used();
m_on_xor(w, ~x, y, z);
return true;
};
for (clause* cp : clauses) {
clause& c = *cp;
if (c.size() != 4 || c.was_used()) continue;
literal w = c[0], x = c[1], y = c[2], z = c[3];
if (try_xor(w, x, y, z, c)) continue;
}
filter(clauses);
}
void npn3_finder::find_and(clause_vector& clauses) {
if (!m_on_and) return;
binary_hash_table_t binaries;
ternary_hash_table_t ternaries;
quaternary_hash_table_t quaternaries;
process_more_clauses(clauses, binaries, ternaries, quaternaries);
const auto try_and = [&](literal w, literal x, literal y, literal z, clause &c) {
if (!implies(w, ~x)) return false;
if (!implies(w, ~y)) return false;
if (!implies(w, ~z)) return false;
c.mark_used();
m_on_and(w, ~x, ~y, ~z);
return true;
};
for (clause* cp : clauses) {
clause& c = *cp;
if (c.size() != 4 || c.was_used()) continue;
literal w = c[0], x = c[1], y = c[2], z = c[3];
if (try_and(w, x, y, z, c)) continue;
if (try_and(x, w, y, z, c)) continue;
if (try_and(y, w, x, z, c)) continue;
if (try_and(z, w, x, y, c)) continue;
}
filter(clauses);
}
void npn3_finder::find_andxor(clause_vector& clauses) {
if (!m_on_andxor) return;