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move flatten functionality to asserted_formulas, sort variables in lut_finder

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2020-02-06 09:16:23 -08:00
parent 38d690650b
commit 8b23a1701a
9 changed files with 88 additions and 57 deletions
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2
src/math/lp/gomory.cpp
View file

@ -78,6 +78,7 @@ class gomory::imp {
m_lcm_den = lcm(m_lcm_den, denominator(new_a));
TRACE("gomory_cut_detail", tout << "new_a = " << new_a << ", k = " << m_k << ", lcm_den = " << m_lcm_den << "\n";);
#if SMALL_CUTS
// if (numerator(new_a).is_big()) throw found_big();
if (numerator(new_a) > m_big_number) throw found_big();
#endif
}
@ -110,6 +111,7 @@ class gomory::imp {
TRACE("gomory_cut_detail_real", tout << a << "*v" << j << " k: " << m_k << "\n";);
m_t.add_monomial(new_a, j);
#if SMALL_CUTS
// if (numerator(new_a).is_big()) throw found_big();
if (numerator(new_a) > m_big_number) throw found_big();
#endif
}

4
src/sat/sat_aig_cuts.cpp
View file

@ -276,13 +276,13 @@ namespace sat {
}
void aig_cuts::add_cut(bool_var v, uint64_t lut, bool_var_vector const& args) {
// args can be assumed to be sorted
DEBUG_CODE(for (unsigned i = 0; i + 1 < args.size(); ++i) VERIFY(args[i] < args[i+1]););
reserve(v);
for (bool_var w : args) reserve(w);
// optional: reshuffle lut and sort variables.
cut c;
for (bool_var w : args) VERIFY(c.add(w));
c.set_table(lut);
// add-don't care?
insert_cut(v, c, m_cuts[v]);
}

7
src/sat/sat_lut_finder.cpp
View file

@ -59,7 +59,13 @@ namespace sat {
s.init_visited();
unsigned mask = 0, i = 0;
m_vars.reset();
m_clause.reset();
for (literal l : c) {
m_clause.push_back(l);
}
// ensure that variables in returned LUT are sorted
std::sort(m_clause.begin(), m_clause.end());
for (literal l : m_clause) {
m_vars.push_back(l.var());
m_var_position[l.var()] = i;
s.mark_visited(l.var());
@ -67,7 +73,6 @@ namespace sat {
}
m_clauses_to_remove.reset();
m_clauses_to_remove.push_back(&c);
m_clause.resize(c.size());
m_combination = 0;
m_num_combinations = 0;
set_combination(mask);

39
src/smt/asserted_formulas.cpp
View file

@ -57,7 +57,8 @@ asserted_formulas::asserted_formulas(ast_manager & m, smt_params & sp, params_re
m_find_macros(*this),
m_propagate_values(*this),
m_nnf_cnf(*this),
m_apply_quasi_macros(*this) {
m_apply_quasi_macros(*this),
m_flatten_clauses(*this) {
m_macro_finder = alloc(macro_finder, m, m_macro_manager);
@ -267,6 +268,7 @@ void asserted_formulas::reduce() {
if (!invoke(m_max_bv_sharing_fn)) return;
if (!invoke(m_elim_bvs_from_quantifiers)) return;
if (!invoke(m_reduce_asserted_formulas)) return;
if (!invoke(m_flatten_clauses)) return;
// if (!invoke(m_propagate_values)) return;
IF_VERBOSE(10, verbose_stream() << "(smt.simplifier-done)\n";);
@ -344,6 +346,41 @@ void asserted_formulas::find_macros_core() {
reduce_and_solve();
}
/**
\brief rewrite (a or (b & c)) to (a or b), (a or c) if the reference count of (b & c) is 1.
This avoids the literal for (b & c)
*/
void asserted_formulas::flatten_clauses() {
if (m.proofs_enabled()) return;
bool change = true;
vector<justified_expr> new_fmls;
while (change) {
change = false;
new_fmls.reset();
unsigned sz = m_formulas.size();
for (unsigned i = m_qhead; i < sz; ++i) {
auto const& j = m_formulas.get(i);
expr* f = j.get_fml(), *a = nullptr, *b = nullptr;
bool decomposed = false;
if (m.is_or(f, a, b) && m.is_not(b, b) && m.is_or(b) && b->get_ref_count() == 1) {
decomposed = true;
}
else if (m.is_or(f, b, a) && m.is_not(b, b) && m.is_or(b) && b->get_ref_count() == 1) {
decomposed = true;
}
if (decomposed) {
for (expr* arg : *to_app(b)) {
justified_expr j1(m, m.mk_or(a, m.is_not(arg, arg) ? arg : m.mk_not(arg)), nullptr);
new_fmls.push_back(j1);
}
continue;
}
new_fmls.push_back(j);
}
swap_asserted_formulas(new_fmls);
}
}
void asserted_formulas::apply_quasi_macros() {
TRACE("before_quasi_macros", display(tout););

10
src/smt/asserted_formulas.h
View file

@ -160,6 +160,15 @@ class asserted_formulas {
void pop(unsigned n) { m_elim.pop(n); }
};
class flatten_clauses_fn : public simplify_fmls {
public:
flatten_clauses_fn(asserted_formulas& af): simplify_fmls(af, "flatten-clauses") {}
void operator()() override { af.flatten_clauses(); }
bool should_apply() const override { return true; }
void simplify(justified_expr const& j, expr_ref& n, proof_ref& p) override { UNREACHABLE(); }
};
void flatten_clauses();
#define MK_SIMPLIFIERA(NAME, FUNCTOR, MSG, APP, ARG, REDUCE) \
class NAME : public simplify_fmls { \
FUNCTOR m_functor; \
@ -198,6 +207,7 @@ class asserted_formulas {
propagate_values_fn m_propagate_values;
nnf_cnf_fn m_nnf_cnf;
apply_quasi_macros_fn m_apply_quasi_macros;
flatten_clauses_fn m_flatten_clauses;
bool invoke(simplify_fmls& s);
void swap_asserted_formulas(vector<justified_expr>& new_fmls);

35
src/smt/smt_context.cpp
View file

@ -1989,22 +1989,37 @@ namespace smt {
}
/**
\brief Update the index used for backward subsumption.
\brief Remove clause
*/
void context::remove_lit_occs(clause const& cls) {
int nbv = get_num_bool_vars();
for (literal l : cls) {
if (l.var() < nbv)
dec_ref(l);
}
}
void context::remove_cls_occs(clause * cls) {
remove_watch_literal(cls, 0);
remove_watch_literal(cls, 1);
remove_lit_occs(*cls);
remove_lit_occs(*cls, get_num_bool_vars());
}
/**
\brief Update occurrence count of literals
*/
void context::add_lit_occs(clause const& cls) {
for (literal l : cls) {
inc_ref(l);
}
}
void context::remove_lit_occs(clause const& cls, unsigned nbv) {
for (literal l : cls) {
if (l.var() < static_cast<int>(nbv))
dec_ref(l);
}
}
// TBD: enable as assertion when ready to re-check
void context::dec_ref(literal l) { if (m_lit_occs[l.index()] > 0) m_lit_occs[l.index()]--; }
void context::inc_ref(literal l) { m_lit_occs[l.index()]++; }
/**
\brief Delete the given clause.
@ -2257,7 +2272,7 @@ namespace smt {
unsigned num = cls->get_num_literals();
remove_lit_occs(*cls);
remove_lit_occs(*cls, num_bool_vars);
unsigned ilvl = 0;
(void)ilvl;

8
src/smt/smt_context.h
View file

@ -839,11 +839,11 @@ namespace smt {
void mk_ite_cnstr(app * n);
void dec_ref(literal l) { if (m_lit_occs[l.index()] > 0) m_lit_occs[l.index()]--; }
void dec_ref(literal l);
void inc_ref(literal l) { m_lit_occs[l.index()]++; }
void inc_ref(literal l);
void remove_lit_occs(clause const& cls);
void remove_lit_occs(clause const& cls, unsigned num_bool_vars);
void add_lit_occs(clause const& cls);
public:
@ -1570,8 +1570,6 @@ namespace smt {
void get_guessed_literals(expr_ref_vector & result);
bool split_binary(app* o, expr*& a, expr_ref& b, expr_ref& c);
void internalize_assertion(expr * n, proof * pr, unsigned generation);
void internalize_proxies(expr_ref_vector const& asms, vector<std::pair<expr*,expr_ref>>& asm2proxy);

3
src/smt/smt_context_inv.cpp
View file

@ -33,7 +33,8 @@ namespace smt {
SASSERT(is_watching_clause(~cls->get_literal(0), cls));
SASSERT(is_watching_clause(~cls->get_literal(1), cls));
for (literal l : *cls) {
// currently does not hold: SASSERT(m_lit_occs[l.index()] > 0);
// holds, TBD re-enable when ready to re-check
// SASSERT(m_lit_occs[l.index()] > 0);
}
return true;
}

37
src/smt/smt_internalizer.cpp
View file

@ -182,27 +182,6 @@ namespace smt {
}
}
bool context::split_binary(app* o, expr*& a, expr_ref& b, expr_ref& c) {
expr* x = nullptr, *y = nullptr, *ny = nullptr, *z = nullptr, *u = nullptr;
if (m.is_or(o, x, y) &&
m.is_not(y, ny) &&
m.is_or(ny, z, u)) {
a = x;
b = m.is_not(z, z) ? z : m.mk_not(z);
c = m.is_not(u, u) ? u : m.mk_not(u);
return true;
}
if (m.is_or(o, y, x) &&
m.is_not(y, ny) &&
m.is_or(ny, z, u)) {
a = x;
b = m.is_not(z, z) ? z : m.mk_not(z);
c = m.is_not(u, u) ? u : m.mk_not(u);
return true;
}
return false;
}
#define DEEP_EXPR_THRESHOLD 1024
@ -251,16 +230,6 @@ namespace smt {
expr* a = nullptr;
expr_ref b(m), c(m);
// perform light-weight rewriting on clauses.
if (!relevancy() && split_binary(to_app(n), a, b, c)) {
internalize(a, true);
internalize(b, true);
internalize(c, true);
literal lits2[2] = { get_literal(a), get_literal(b) };
literal lits3[2] = { get_literal(a), get_literal(c) };
mk_root_clause(2, lits2, pr);
mk_root_clause(2, lits3, pr);
break;
}
for (expr * arg : *to_app(n)) {
internalize(arg, true);
lits.push_back(get_literal(arg));
@ -1479,12 +1448,6 @@ namespace smt {
}}
}
void context::add_lit_occs(clause const& cls) {
for (literal l : cls) {
inc_ref(l);
}
}
void context::mk_clause(literal l1, literal l2, justification * j) {
literal ls[2] = { l1, l2 };
mk_clause(2, ls, j);