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additional bit-vector propagators (#4695)

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
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Nikolaj Bjorner 2020-09-18 12:38:29 -07:00 • committed by GitHub
parent 549753845e
commit 8691ef1d4d
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GPG key ID: 4AEE18F83AFDEB23
17 changed files with 423 additions and 121 deletions
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72
src/sat/smt/bv_internalize.cpp
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@ -42,6 +42,16 @@ namespace bv {
}
};
class solver::add_eq_occurs_trail : public trail<euf::solver> {
solver::bit_atom* m_atom;
public:
add_eq_occurs_trail(solver::bit_atom* a) :m_atom(a) {}
void undo(euf::solver& euf) override {
SASSERT(m_atom->m_eqs);
m_atom->m_eqs = m_atom->m_eqs->m_next;
}
};
class solver::mk_atom_trail : public trail<euf::solver> {
solver& th;
sat::bool_var m_var;
@ -242,10 +252,15 @@ namespace bv {
}
solver::bit_atom* solver::mk_bit_atom(sat::bool_var bv) {
bit_atom* b = new (get_region()) bit_atom();
insert_bv2a(bv, b);
ctx.push(mk_atom_trail(bv, *this));
return b;
atom* a = get_bv2a(bv);
if (a)
return a->is_bit() ? &a->to_bit() : nullptr;
else {
bit_atom* b = new (get_region()) bit_atom();
insert_bv2a(bv, b);
ctx.push(mk_atom_trail(bv, *this));
return b;
}
}
void solver::set_bit_eh(theory_var v, literal l, unsigned idx) {
@ -253,20 +268,14 @@ namespace bv {
if (s().value(l) != l_undef && s().lvl(l) == 0)
register_true_false_bit(v, idx);
else {
atom* a = get_bv2a(l.var());
if (a && !a->is_bit())
;
else if (a) {
bit_atom* b = &a->to_bit();
find_new_diseq_axioms(*b, v, idx);
ctx.push(add_var_pos_trail(b));
bit_atom* b = mk_bit_atom(l.var());
if (b) {
if (b->m_occs)
find_new_diseq_axioms(*b, v, idx);
if (!b->is_fresh())
ctx.push(add_var_pos_trail(b));
b->m_occs = new (get_region()) var_pos_occ(v, idx, b->m_occs);
}
else {
bit_atom* b = mk_bit_atom(l.var());
SASSERT(!b->m_occs);
b->m_occs = new (get_region()) var_pos_occ(v, idx);
}
}
}
@ -570,12 +579,34 @@ namespace bv {
}
}
void solver::eq_internalized(euf::enode* n) {
SASSERT(m.is_eq(n->get_expr()));
theory_var v1 = n->get_arg(0)->get_th_var(get_id());
theory_var v2 = n->get_arg(1)->get_th_var(get_id());
SASSERT(v1 != euf::null_theory_var);
SASSERT(v2 != euf::null_theory_var);
unsigned sz = m_bits[v1].size();
for (unsigned i = 0; i < sz; ++i) {
eq_internalized(m_bits[v1][i].var(), i, v1, v2, n);
eq_internalized(m_bits[v2][i].var(), i, v2, v1, n);
}
}
void solver::eq_internalized(sat::bool_var b, unsigned idx, theory_var v1, theory_var v2, euf::enode* n) {
bit_atom* a = mk_bit_atom(b);
if (a) {
if (!a->is_fresh())
ctx.push(add_eq_occurs_trail(a));
a->m_eqs = new (get_region()) eq_occurs(idx, v1, v2, n, a->m_eqs);
}
}
void solver::assert_ackerman(theory_var v1, theory_var v2) {
if (v1 == v2)
return;
if (v1 > v2)
std::swap(v1, v2);
flet<bool> _red(m_is_redundant, true);
flet<bool> _red(m_is_redundant, true);
++m_stats.m_ackerman;
expr* o1 = var2expr(v1);
expr* o2 = var2expr(v2);
@ -584,6 +615,7 @@ namespace bv {
unsigned sz = m_bits[v1].size();
TRACE("bv", tout << "ackerman-eq: " << s().scope_lvl() << " " << oe << "\n";);
literal_vector eqs;
eqs.push_back(oeq);
for (unsigned i = 0; i < sz; ++i) {
literal l1 = m_bits[v1][i];
literal l2 = m_bits[v2][i];
@ -592,14 +624,10 @@ namespace bv {
e2 = bv.mk_bit2bool(o2, i);
expr_ref e = mk_eq(e1, e2);
literal eq = ctx.internalize(e, false, false, m_is_redundant);
add_clause(l1, ~l2, ~eq);
add_clause(~l1, l2, ~eq);
add_clause(l1, l2, eq);
add_clause(~l1, ~l2, eq);
add_clause(eq, ~oeq);
eqs.push_back(~eq);
}
eqs.push_back(oeq);
TRACE("bv", for (auto l : eqs) tout << mk_bounded_pp(literal2expr(l), m) << " "; tout << "\n";);
s().add_clause(eqs.size(), eqs.c_ptr(), sat::status::th(m_is_redundant, get_id()));
}
}