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expose incremental cubing over API

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2017-09-28 15:05:10 -07:00
parent e507a6ccd1
commit a625301a41
10 changed files with 63 additions and 68 deletions
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84
src/sat/sat_lookahead.cpp
View file

@ -657,7 +657,6 @@ namespace sat {
}
// case watched::EXTERNAL:
}
// std::cout << "tsum: " << tsum << "\n";
}
#endif
// std::cout << "sum: " << sum << " afactor " << afactor << " sqfactor " << sqfactor << " tsum " << tsum << "\n";
@ -2221,7 +2220,7 @@ namespace sat {
SASSERT(dl_no_overflow(base));
unsigned dl_truth = base + 2 * m_lookahead.size() * (m_config.m_dl_max_iterations + 1);
scoped_level _sl(*this, dl_truth);
IF_VERBOSE(2, verbose_stream() << "double: " << l << "\n";);
IF_VERBOSE(2, verbose_stream() << "double: " << l << " depth: " << m_trail_lim.size() << "\n";);
init_lookahead_reward();
assign(l);
propagate();
@ -2353,63 +2352,24 @@ namespace sat {
}
lbool lookahead::cube() {
#if 0
literal_vector lits;
while (true) {
lbool result = cube(lits);
if (lits.empty() || result != l_undef) {
return result;
}
display_cube(std::cout, cube);
}
#endif
lbool result = l_false;
init_search();
m_model.reset();
scoped_level _sl(*this, c_fixed_truth);
literal_vector cube;
svector<bool> is_decision;
m_search_mode = lookahead_mode::searching;
double freevars_threshold = 0;
while (true) {
TRACE("sat", display(tout););
inc_istamp();
checkpoint();
literal l = choose();
if (inconsistent()) {
TRACE("sat", tout << "inconsistent: " << cube << "\n";);
freevars_threshold = m_freevars.size();
if (!backtrack(cube, is_decision)) return result;
continue;
}
if (l == null_literal) {
return l_true;
}
unsigned depth = cube.size();
if ((m_config.m_cube_cutoff != 0 && depth == m_config.m_cube_cutoff) ||
(m_config.m_cube_cutoff == 0 && m_freevars.size() < freevars_threshold)) {
display_cube(std::cout, cube);
freevars_threshold *= (1.0 - pow(m_config.m_cube_fraction, depth));
result = l_undef;
set_conflict();
if (!backtrack(cube, is_decision)) return result;
continue;
}
TRACE("sat", tout << "choose: " << l << " cube: " << cube << "\n";);
++m_stats.m_decisions;
push(l, c_fixed_truth);
cube.push_back(l);
is_decision.push_back(true);
SASSERT(inconsistent() || !is_unsat());
display_cube(std::cout, lits);
}
return l_undef;
}
lbool lookahead::cube(literal_vector& lits) {
lits.reset();
bool is_first = (m_cube_state.m_lit == null_literal);
bool is_first = m_cube_state.m_first;
if (is_first) {
init_search();
m_model.reset();
m_cube_state.m_first = false;
}
scoped_level _sl(*this, c_fixed_truth);
m_search_mode = lookahead_mode::searching;
@ -2421,39 +2381,43 @@ namespace sat {
while (true) {
TRACE("sat", display(tout););
inc_istamp();
checkpoint();
m_cube_state.m_lit = choose();
inc_istamp();
if (inconsistent()) {
TRACE("sat", tout << "inconsistent: " << cube << "\n";);
TRACE("sat", tout << "inconsistent: " << m_cube_state.m_cube << "\n";);
m_cube_state.m_freevars_threshold = m_freevars.size();
if (!backtrack(m_cube_state.m_cube, m_cube_state.m_is_decision)) return m_cube_state.m_result;
if (!backtrack(m_cube_state.m_cube, m_cube_state.m_is_decision)) return l_false;
continue;
}
if (m_cube_state.m_lit == null_literal) {
return l_true;
}
pick_up_work:
depth = m_cube_state.m_cube.size();
if ((m_config.m_cube_cutoff != 0 && depth == m_config.m_cube_cutoff) ||
(m_config.m_cube_cutoff == 0 && m_freevars.size() < m_cube_state.m_freevars_threshold)) {
m_cube_state.m_freevars_threshold *= (1.0 - pow(m_config.m_cube_fraction, depth));
m_cube_state.m_result = l_undef;
set_conflict();
if (!backtrack(m_cube_state.m_cube, m_cube_state.m_is_decision)) return m_cube_state.m_result;
lits.append(m_cube_state.m_cube);
backtrack(m_cube_state.m_cube, m_cube_state.m_is_decision);
return l_undef;
}
pick_up_work:
TRACE("sat", tout << "choose: " << m_cube_state.m_lit << " cube: " << m_cube_state.m_cube << "\n";);
literal lit = choose();
if (inconsistent()) {
TRACE("sat", tout << "inconsistent: " << m_cube_state.m_cube << "\n";);
m_cube_state.m_freevars_threshold = m_freevars.size();
if (!backtrack(m_cube_state.m_cube, m_cube_state.m_is_decision)) return l_false;
continue;
}
if (lit == null_literal) {
return l_true;
}
TRACE("sat", tout << "choose: " << lit << " cube: " << m_cube_state.m_cube << "\n";);
++m_stats.m_decisions;
push(m_cube_state.m_lit, c_fixed_truth);
m_cube_state.m_cube.push_back(m_cube_state.m_lit);
push(lit, c_fixed_truth);
m_cube_state.m_cube.push_back(lit);
m_cube_state.m_is_decision.push_back(true);
SASSERT(inconsistent() || !is_unsat());
}
lbool result = m_cube_state.m_result;
m_cube_state.reset();
return result;
return l_undef;
}
void lookahead::init_model() {

6
src/sat/sat_lookahead.h
View file

@ -140,17 +140,15 @@ namespace sat {
#endif
struct cube_state {
bool m_first;
svector<bool> m_is_decision;
literal_vector m_cube;
literal m_lit;
lbool m_result;
double m_freevars_threshold;
cube_state() { reset(); }
void reset() {
m_first = true;
m_is_decision.reset();
m_cube.reset();
m_lit = null_literal;
m_result = l_false;
m_freevars_threshold = 0;
}
};

2
src/sat/sat_params.pyg
View file

@ -40,7 +40,7 @@ def_module_params('sat',
('lookahead.cube.cutoff', UINT, 0, 'cut-off depth to create cubes. Only enabled when non-zero. Used when lookahead_cube is true.'),
('lookahead_search', BOOL, False, 'use lookahead solver'),
('lookahead_simplify', BOOL, False, 'use lookahead solver during simplification'),
('lookahead.reward', SYMBOL, 'heuleu', 'select lookahead heuristic: ternary, hs (Heule Schur), heuleu (Heule Unit), or unit'),
('lookahead.reward', SYMBOL, 'heuleu', 'select lookahead heuristic: ternary, heule_schur (Heule Schur), heuleu (Heule Unit), or unit'),
('dimacs.display', BOOL, False, 'display SAT instance in DIMACS format and return unknown instead of solving'),
('dimacs.inprocess.display', BOOL, False, 'display SAT instance in DIMACS format if unsolved after inprocess.max inprocessing passes')))

8
src/sat/sat_solver/inc_sat_solver.cpp
View file

@ -345,6 +345,14 @@ public:
return result;
}
virtual expr_ref cube() {
if (!m_internalized) {
dep2asm_t dep2asm;
m_model = 0;
lbool r = internalize_formulas();
if (r != l_true) return expr_ref(m.mk_true(), m);
m_internalized = true;
}
convert_internalized();
sat::literal_vector lits;
lbool result = m_solver.cube(lits);
if (result == l_false || lits.empty()) {