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Repropagate the conflict clause

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This commit is contained in:
Jakob Rath 2023-03-05 18:13:45 +01:00
parent 666c937b06
commit 4f96249570
1 changed files with 37 additions and 4 deletions
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41
src/math/polysat/solver.cpp
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@ -84,11 +84,14 @@ namespace polysat {
else if (should_add_pwatch()) add_pwatch(); else if (should_add_pwatch()) add_pwatch();
else if (can_propagate()) propagate(); else if (can_propagate()) propagate();
else if (can_repropagate()) repropagate(); else if (can_repropagate()) repropagate();
else if (!can_decide()) { LOG_H2("SAT"); VERIFY(verify_sat()); return l_true; } else {
VERIFY(bool_watch_invariant()); // TODO: merge propagate/repropagate and move this assertion there.
if (!can_decide()) { LOG_H2("SAT"); VERIFY(verify_sat()); return l_true; }
else if (m_constraints.should_gc()) m_constraints.gc(); else if (m_constraints.should_gc()) m_constraints.gc();
else if (m_simplify.should_apply()) m_simplify(); else if (m_simplify.should_apply()) m_simplify();
else if (m_restart.should_apply()) m_restart(); else if (m_restart.should_apply()) m_restart();
else decide(); else decide();
}
} }
LOG_H2("UNDEF (resource limit)"); LOG_H2("UNDEF (resource limit)");
return l_undef; return l_undef;
@ -228,6 +231,7 @@ namespace polysat {
m_repropagate_units.pop_back(); m_repropagate_units.pop_back();
VERIFY_EQ(cl.size(), 1); VERIFY_EQ(cl.size(), 1);
sat::literal lit = cl[0]; sat::literal lit = cl[0];
LOG("Repropagate unit: " << lit_pp(*this, lit));
switch (m_bvars.value(lit)) { switch (m_bvars.value(lit)) {
case l_undef: case l_undef:
assign_propagate(lit, cl); assign_propagate(lit, cl);
@ -265,8 +269,9 @@ namespace polysat {
sat::literal lit = m_repropagate_lits.back(); sat::literal lit = m_repropagate_lits.back();
m_repropagate_lits.pop_back(); m_repropagate_lits.pop_back();
repropagate(lit); repropagate(lit);
// TODO: should we interleave this with regular propagation?
// (after each successful repropagated literal, do normal propagation)
} }
SASSERT(bool_watch_invariant());
} }
/** /**
@ -1118,20 +1123,48 @@ namespace polysat {
// Explicit boolean propagation over the given clause, without relying on watch lists. // Explicit boolean propagation over the given clause, without relying on watch lists.
void solver::propagate_clause(clause& cl) { void solver::propagate_clause(clause& cl) {
// LOG("search: " << m_search);
// LOG("prop queue:" << m_prop);
LOG("propagate_clause: " << cl);
for (sat::literal lit : cl) {
LOG(" " << lit_pp(*this, lit));
// will be repropagated in reverse order, so the tail literals are assigned before trying the watched ones.
m_repropagate_lits.push_back(lit);
}
return;
#if 0
// TODO: by invariants of watchlist-based propagation, shouldn't it be enough to check the first two literals of the clause?
sat::literal prop = sat::null_literal; sat::literal prop = sat::null_literal;
for (sat::literal lit : cl) { for (sat::literal lit : cl) {
if (m_bvars.is_true(lit)) if (m_bvars.is_true(lit)) {
VERIFY(cl.size() != 1 || cl[0] == lit);
VERIFY(cl.size() < 2 || cl[0] == lit || cl[1] == lit);
return; // clause is true return; // clause is true
}
if (m_bvars.is_false(lit)) if (m_bvars.is_false(lit))
continue; continue;
SASSERT(!m_bvars.is_assigned(lit)); SASSERT(!m_bvars.is_assigned(lit));
if (prop != sat::null_literal) if (prop != sat::null_literal) {
// TODO: must update other watch if assert is violated.
// verbose_stream() << " clause " << cl << "\n";
// for (sat::literal l : cl)
// verbose_stream() << " " << lit_pp(*this, l) << "\n";
// if (m_bvars.is_assigned(cl[0])) {
// verbose_stream() << " aaaaaaah " << cl << "\n";
// }
// VERIFY(!m_bvars.is_assigned(cl[0]));
// VERIFY(!m_bvars.is_assigned(cl[1]));
return; // two or more undef literals return; // two or more undef literals
}
prop = lit; prop = lit;
} }
if (prop == sat::null_literal) if (prop == sat::null_literal)
return; return;
VERIFY(!m_bvars.is_assigned(cl[0]) || !m_bvars.is_assigned(cl[1]));
VERIFY(m_bvars.is_false(cl[0]) || m_bvars.is_false(cl[1]));
// verbose_stream() << "PROP " << prop << "\n";
assign_propagate(prop, cl); assign_propagate(prop, cl);
#endif
} }
unsigned solver::level(sat::literal lit0, clause const& cl) { unsigned solver::level(sat::literal lit0, clause const& cl) {