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init search before returning

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2017-06-11 13:08:05 -07:00
parent b266af3e08
commit af6ebbcd92
16 changed files with 90 additions and 37 deletions
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34
src/sat/sat_lookahead.cpp
View file

@ -30,6 +30,18 @@ namespace sat {
if (p.m_s.m_ext) p.m_s.m_ext->set_lookahead(0);
}
lookahead::scoped_assumptions::scoped_assumptions(lookahead& p, literal_vector const& lits): p(p), lits(lits) {
for (auto l : lits) {
p.push(l, p.c_fixed_truth);
}
}
lookahead::scoped_assumptions::~scoped_assumptions() {
for (auto l : lits) {
p.pop();
}
}
void lookahead::flip_prefix() {
if (m_trail_lim.size() < 64) {
uint64 mask = (1ull << m_trail_lim.size());
@ -1612,7 +1624,7 @@ namespace sat {
}
literal lookahead::select_lookahead(bool_var_vector const& vars) {
literal lookahead::select_lookahead(literal_vector const& assumptions, bool_var_vector const& vars) {
IF_VERBOSE(1, verbose_stream() << "(sat-select " << vars.size() << ")\n";);
scoped_ext _sext(*this);
m_search_mode = lookahead_mode::searching;
@ -1623,19 +1635,25 @@ namespace sat {
for (auto v : vars) {
m_select_lookahead_vars.insert(v);
}
scoped_assumptions _sa(*this, assumptions);
literal l = choose();
m_select_lookahead_vars.reset();
if (inconsistent()) return null_literal;
if (inconsistent()) l = null_literal;
#if 0
// assign unit literals that were found during search for lookahead.
unsigned num_assigned = 0;
for (literal lit : m_trail) {
if (!m_s.was_eliminated(lit.var()) && m_s.value(lit) != l_true) {
m_s.assign(lit, justification());
++num_assigned;
if (assumptions.empty()) {
unsigned num_assigned = 0;
for (literal lit : m_trail) {
if (!m_s.was_eliminated(lit.var()) && m_s.value(lit) != l_true) {
m_s.assign(lit, justification());
++num_assigned;
}
}
IF_VERBOSE(1, verbose_stream() << "(sat-lookahead :units " << num_assigned << ")\n";);
}
IF_VERBOSE(1, verbose_stream() << "(sat-lookahead :units " << num_assigned << ")\n";);
#endif
return l;
}

10
src/sat/sat_lookahead.h
View file

@ -199,6 +199,14 @@ namespace sat {
~scoped_ext();
};
class scoped_assumptions {
lookahead& p;
literal_vector lits;
public:
scoped_assumptions(lookahead& p, literal_vector const& lits);
~scoped_assumptions();
};
// -------------------------------------
// prefix updates. I use low order bits.
@ -447,7 +455,7 @@ namespace sat {
return search();
}
literal select_lookahead(bool_var_vector const& vars);
literal select_lookahead(literal_vector const& assumptions, bool_var_vector const& vars);
/**
\brief simplify set of clauses by extracting units from a lookahead at base level.
*/

11
src/sat/sat_solver.cpp
View file

@ -811,14 +811,9 @@ namespace sat {
return r;
}
literal solver::select_lookahead(bool_var_vector const& vars) {
literal solver::select_lookahead(literal_vector const& assumptions, bool_var_vector const& vars) {
lookahead lh(*this);
literal result = lh.select_lookahead(vars);
if (result == null_literal) {
set_conflict(justification());
}
// extract unit literals from lh
return result;
return lh.select_lookahead(assumptions, vars);
}
// -----------------------
@ -851,8 +846,8 @@ namespace sat {
}
#endif
try {
if (inconsistent()) return l_false;
init_search();
if (inconsistent()) return l_false;
propagate(false);
if (inconsistent()) return l_false;
init_assumptions(num_lits, lits);

2
src/sat/sat_solver.h
View file

@ -355,7 +355,7 @@ namespace sat {
void set_model(model const& mdl);
char const* get_reason_unknown() const { return m_reason_unknown.c_str(); }
literal select_lookahead(bool_var_vector const& vars);
literal select_lookahead(literal_vector const& assumptions, bool_var_vector const& vars);
protected:
unsigned m_conflicts;

27
src/sat/sat_solver/inc_sat_solver.cpp
View file

@ -148,6 +148,8 @@ public:
virtual lbool check_sat(unsigned sz, expr * const * assumptions) {
m_solver.pop_to_base_level();
m_core.reset();
if (m_solver.inconsistent()) return l_false;
expr_ref_vector _assumptions(m);
obj_map<expr, expr*> asm2fml;
for (unsigned i = 0; i < sz; ++i) {
@ -280,9 +282,10 @@ public:
return 0;
}
virtual expr_ref lookahead(expr_ref_vector const& candidates) {
virtual expr_ref lookahead(expr_ref_vector const& assumptions, expr_ref_vector const& candidates) {
IF_VERBOSE(1, verbose_stream() << "(sat-lookahead " << candidates.size() << ")\n";);
sat::bool_var_vector vars;
sat::literal_vector lits;
expr_ref_vector lit2expr(m);
lit2expr.resize(m_solver.num_vars() * 2);
m_map.mk_inv(lit2expr);
@ -292,11 +295,29 @@ public:
vars.push_back(v);
}
}
for (auto c : assumptions) {
SASSERT(is_literal(c));
sat::bool_var v = sat::null_bool_var;
bool sign = false;
expr* e = c;
while (m.is_not(e, e)) {
sign = !sign;
}
if (is_uninterp_const(e)) {
v = m_map.to_bool_var(e);
}
if (v != sat::null_bool_var) {
lits.push_back(sat::literal(v, sign));
}
else {
IF_VERBOSE(0, verbose_stream() << "WARNING: could not handle " << mk_pp(c, m) << "\n";);
}
}
IF_VERBOSE(1, verbose_stream() << "vars: " << vars.size() << "\n";);
if (vars.empty()) {
return expr_ref(m.mk_true(), m);
}
sat::literal l = m_solver.select_lookahead(vars);
sat::literal l = m_solver.select_lookahead(lits, vars);
if (m_solver.inconsistent()) {
IF_VERBOSE(1, verbose_stream() << "(sat-lookahead inconsistent)\n";);
return expr_ref(m.mk_false(), m);
@ -715,7 +736,7 @@ private:
if (asm2fml.contains(e)) {
e = asm2fml.find(e);
}
m_core.push_back(e);
m_core.push_back(e);
}
}