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align translation cache with scopes and variable elimination

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This commit is contained in:
Nikolaj Bjorner 2021-03-03 11:22:17 -08:00
parent 11efe33aa0
commit 69070a7486
7 changed files with 65 additions and 19 deletions
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1
src/sat/sat_extension.h
View file

@ -91,6 +91,7 @@ namespace sat {
virtual void get_antecedents(literal l, ext_justification_idx idx, literal_vector & r, bool probing) = 0;
virtual bool is_extended_binary(ext_justification_idx idx, literal_vector & r) { return false; }
virtual void asserted(literal l) {};
virtual void set_eliminated(bool_var v) {};
virtual check_result check() = 0;
virtual lbool resolve_conflict() { return l_undef; } // stores result in sat::solver::m_lemma
virtual void push() = 0;

7
src/sat/sat_solver.cpp
View file

@ -328,14 +328,19 @@ namespace sat {
}
void solver::set_eliminated(bool_var v, bool f) {
if (m_eliminated[v] && !f)
if (m_eliminated[v] == f)
return;
if (!f)
reset_var(v, m_external[v], m_decision[v]);
else if (f && m_ext)
m_ext->set_eliminated(v);
m_eliminated[v] = f;
}
clause* solver::mk_clause(unsigned num_lits, literal * lits, sat::status st) {
m_model_is_current = false;
for (unsigned i = 0; i < num_lits; i++)
VERIFY(!was_eliminated(lits[i]));

10
src/sat/smt/euf_internalize.cpp
View file

@ -128,6 +128,7 @@ namespace euf {
s().set_external(v);
s().set_eliminated(v, false);
if (lit.sign()) {
v = si.add_bool_var(e);
s().set_external(v);
@ -265,17 +266,18 @@ namespace euf {
sat::status st = sat::status::th(m_is_redundant, m.get_basic_family_id());
expr* c = nullptr, * th = nullptr, * el = nullptr;
if (!m.is_bool(e) && m.is_ite(e, c, th, el)) {
app* a = to_app(e);
expr_ref eq_th = mk_eq(a, th);
expr_ref eq_th = mk_eq(e, th);
sat::literal lit_th = mk_literal(eq_th);
if (th == el) {
s().add_clause(1, &lit_th, st);
}
else {
sat::bool_var v = si.to_bool_var(c);
VERIFY(v != sat::null_bool_var);
VERIFY(s().is_external(v));
SASSERT(v != sat::null_bool_var);
expr_ref eq_el = mk_eq(a, el);
VERIFY(!s().was_eliminated(v));
expr_ref eq_el = mk_eq(e, el);
sat::literal lit_el = mk_literal(eq_el);
literal lits1[2] = { literal(v, true), lit_th };

5
src/sat/smt/euf_solver.cpp
View file

@ -279,6 +279,11 @@ namespace euf {
}
}
void solver::set_eliminated(bool_var v) {
si.uncache(literal(v, false));
si.uncache(literal(v, true));
}
void solver::asserted(literal l) {
expr* e = m_bool_var2expr.get(l.var(), nullptr);
if (!e) {

1
src/sat/smt/euf_solver.h
View file

@ -293,6 +293,7 @@ namespace euf {
void get_antecedents(literal l, th_explain& jst, literal_vector& r, bool probing);
void add_antecedent(enode* a, enode* b);
void add_diseq_antecedent(enode* a, enode* b);
void set_eliminated(bool_var v) override;
void asserted(literal l) override;
sat::check_result check() override;
void push() override;

1
src/sat/smt/sat_smt.h
View file

@ -36,6 +36,7 @@ namespace sat {
virtual bool_var to_bool_var(expr* e) = 0;
virtual bool_var add_bool_var(expr* e) = 0;
virtual void cache(app* t, literal l) = 0;
virtual void uncache(literal l) = 0;
virtual void push() = 0;
virtual void pop(unsigned n) = 0;
virtual void set_expr2var_replay(obj_map<expr, sat::bool_var>* r) = 0;

59
src/sat/tactic/goal2sat.cpp
View file

@ -60,7 +60,10 @@ struct goal2sat::imp : public sat::sat_internalizer {
pb_util pb;
svector<frame> m_frame_stack;
svector<sat::literal> m_result_stack;
obj_map<app, sat::literal> m_cache;
obj_map<app, sat::literal> m_app2lit;
u_map<app*> m_lit2app;
unsigned_vector m_cache_lim;
ptr_vector<app> m_cache_trail;
obj_hashtable<expr> m_interface_vars;
sat::solver_core & m_solver;
atom2bool_var & m_map;
@ -205,12 +208,11 @@ struct goal2sat::imp : public sat::sat_internalizer {
sat::bool_var v = m_map.to_bool_var(e);
if (v != sat::null_bool_var)
return v;
if (is_app(e) && m_cache.find(to_app(e), l) && !l.sign())
if (is_app(e) && m_app2lit.find(to_app(e), l) && !l.sign())
return l.var();
return sat::null_bool_var;
}
void set_expr2var_replay(obj_map<expr, sat::bool_var>* r) override {
m_expr2var_replay = r;
}
@ -236,8 +238,10 @@ struct goal2sat::imp : public sat::sat_internalizer {
unsigned m_num_scopes{ 0 };
void force_push() {
for (; m_num_scopes > 0; --m_num_scopes)
for (; m_num_scopes > 0; --m_num_scopes) {
m_map.push();
m_cache_lim.push_back(m_cache_trail.size());
}
}
void push() override {
@ -251,12 +255,37 @@ struct goal2sat::imp : public sat::sat_internalizer {
}
n -= m_num_scopes;
m_num_scopes = 0;
m_cache.reset();
m_map.pop(n);
unsigned k = m_cache_lim[m_cache_lim.size() - n];
for (; k-- > m_cache_trail.size(); ) {
app* t = m_cache_trail[k];
sat::literal lit;
if (m_app2lit.find(t, lit)) {
m_app2lit.remove(t);
m_lit2app.remove(lit.index());
}
}
m_cache_trail.shrink(k);
m_cache_lim.shrink(m_cache_lim.size() - n);
}
// remove non-external literals from cache.
void uncache(sat::literal lit) override {
app* t = nullptr;
if (m_lit2app.find(lit.index(), t)) {
m_lit2app.remove(lit.index());
m_app2lit.remove(t);
}
}
void cache(app* t, sat::literal l) override {
m_cache.insert(t, l);
SASSERT(m_num_scopes == 0);
SASSERT(!m_app2lit.contains(t));
SASSERT(!m_lit2app.contains(l.index()));
m_app2lit.insert(t, l);
m_lit2app.insert(l.index(), t);
m_cache_trail.push_back(t);
}
void convert_atom(expr * t, bool root, bool sign) {
@ -317,7 +346,7 @@ struct goal2sat::imp : public sat::sat_internalizer {
bool process_cached(app* t, bool root, bool sign) {
sat::literal l = sat::null_literal;
if (!m_cache.find(t, l))
if (!m_app2lit.find(t, l))
return false;
if (sign)
l.neg();
@ -396,7 +425,7 @@ struct goal2sat::imp : public sat::sat_internalizer {
SASSERT(num <= m_result_stack.size());
sat::bool_var k = add_var(false, t);
sat::literal l(k, false);
m_cache.insert(t, l);
cache(t, l);
sat::literal * lits = m_result_stack.end() - num;
for (unsigned i = 0; i < num; i++)
mk_clause(~lits[i], l);
@ -445,7 +474,7 @@ struct goal2sat::imp : public sat::sat_internalizer {
SASSERT(num <= m_result_stack.size());
sat::bool_var k = add_var(false, t);
sat::literal l(k, false);
m_cache.insert(t, l);
cache(t, l);
sat::literal * lits = m_result_stack.end() - num;
// l => /\ lits
@ -497,7 +526,7 @@ struct goal2sat::imp : public sat::sat_internalizer {
else {
sat::bool_var k = add_var(false, n);
sat::literal l(k, false);
m_cache.insert(n, l);
cache(n, l);
mk_clause(~l, ~c, t);
mk_clause(~l, c, e);
mk_clause(l, ~c, ~t);
@ -534,7 +563,7 @@ struct goal2sat::imp : public sat::sat_internalizer {
else {
sat::bool_var k = add_var(false, t);
sat::literal l(k, false);
m_cache.insert(t, l);
cache(t, l);
// l <=> (l1 => l2)
mk_clause(~l, ~l1, l2);
mk_clause(l1, l);
@ -571,7 +600,7 @@ struct goal2sat::imp : public sat::sat_internalizer {
mk_clause(l, l1, l2);
mk_clause(l, ~l1, ~l2);
if (aig()) aig()->add_iff(l, l1, l2);
m_cache.insert(t, m.is_xor(t) ? ~l : l);
cache(t, m.is_xor(t) ? ~l : l);
if (sign)
l.neg();
m_result_stack.push_back(l);
@ -787,8 +816,10 @@ struct goal2sat::imp : public sat::sat_internalizer {
SASSERT(m_result_stack.size() == sz + 1);
sat::literal result = m_result_stack.back();
m_result_stack.pop_back();
if (!result.sign() && m_map.to_bool_var(n) == sat::null_bool_var)
if (!result.sign() && m_map.to_bool_var(n) == sat::null_bool_var) {
m_map.insert(n, result.var());
m_solver.set_external(result.var());
}
return result;
}
@ -853,7 +884,7 @@ struct goal2sat::imp : public sat::sat_internalizer {
scoped_reset(imp& i) :i(i) {}
~scoped_reset() {
i.m_interface_vars.reset();
i.m_cache.reset();
i.m_app2lit.reset();
}
};
scoped_reset _reset(*this);