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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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17 changed files with 423 additions and 121 deletions
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84
src/sat/smt/bv_solver.h
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@ -43,23 +43,29 @@ namespace bv {
friend class ackerman;
struct stats {
unsigned m_num_diseq_static, m_num_diseq_dynamic, m_num_bit2core, m_num_th2core_eq, m_num_conflicts;
unsigned m_num_diseq_static, m_num_diseq_dynamic, m_num_conflicts;
unsigned m_num_bit2core, m_num_th2core_eq, m_num_th2core_diseq, m_num_nbit2core;
unsigned m_ackerman;
void reset() { memset(this, 0, sizeof(stats)); }
stats() { reset(); }
};
struct bv_justification {
enum kind_t { bv2bit, bit2bv };
enum kind_t { eq2bit, ne2bit, bit2eq, bit2ne };
kind_t m_kind;
theory_var m_v1;
theory_var m_v2;
theory_var m_v1{ euf::null_theory_var };
theory_var m_v2 { euf::null_theory_var };
unsigned m_idx{ UINT_MAX };
sat::literal m_consequent;
sat::literal m_antecedent;
bv_justification(theory_var v1, theory_var v2, sat::literal c, sat::literal a) :
m_kind(kind_t::bv2bit), m_v1(v1), m_v2(v2), m_consequent(c), m_antecedent(a) {}
m_kind(bv_justification::kind_t::eq2bit), m_v1(v1), m_v2(v2), m_consequent(c), m_antecedent(a) {}
bv_justification(theory_var v1, theory_var v2):
m_kind(kind_t::bit2bv), m_v1(v1), m_v2(v2) {}
m_kind(bv_justification::kind_t::bit2eq), m_v1(v1), m_v2(v2) {}
bv_justification(unsigned idx, sat::literal c) :
m_kind(bv_justification::kind_t::bit2ne), m_idx(idx), m_consequent(c) {}
bv_justification(unsigned idx, theory_var v1, theory_var v2, sat::literal c, sat::literal a) :
m_kind(bv_justification::kind_t::ne2bit), m_idx(idx), m_v1(v1), m_v2(v2), m_consequent(c), m_antecedent(a) {}
sat::ext_constraint_idx to_index() const {
return sat::constraint_base::mem2base(this);
}
@ -69,8 +75,10 @@ namespace bv {
static size_t get_obj_size() { return sat::constraint_base::obj_size(sizeof(bv_justification)); }
};
sat::justification mk_bv2bit_justification(theory_var v1, theory_var v2, sat::literal c, sat::literal a);
sat::ext_justification_idx mk_bit2bv_justification(theory_var v1, theory_var v2);
sat::justification mk_eq2bit_justification(theory_var v1, theory_var v2, sat::literal c, sat::literal a);
sat::ext_justification_idx mk_bit2eq_justification(theory_var v1, theory_var v2);
sat::justification mk_bit2ne_justification(unsigned idx, sat::literal c);
sat::justification mk_ne2bit_justification(unsigned idx, theory_var v1, theory_var v2, sat::literal c, sat::literal a);
void log_drat(bv_justification const& c);
@ -125,13 +133,46 @@ namespace bv {
bool operator!=(var_pos_it const& other) const { return !(*this == other); }
};
struct eq_occurs {
unsigned m_idx;
theory_var m_v1;
theory_var m_v2;
euf::enode* m_node;
eq_occurs* m_next;
eq_occurs(unsigned idx, theory_var v1, theory_var v2, euf::enode* n, eq_occurs* next = nullptr):
m_idx(idx), m_v1(v1), m_v2(v2), m_node(n), m_next(next) {}
};
class eq_occurs_it {
eq_occurs* m_first;
public:
eq_occurs_it(eq_occurs* c) : m_first(c) {}
eq_occurs operator*() { return *m_first; }
eq_occurs_it& operator++() { m_first = m_first->m_next; return *this; }
eq_occurs_it operator++(int) { eq_occurs_it tmp = *this; ++* this; return tmp; }
bool operator==(eq_occurs_it const& other) const { return m_first == other.m_first; }
bool operator!=(eq_occurs_it const& other) const { return !(*this == other); }
};
struct bit_atom : public atom {
var_pos_occ * m_occs;
bit_atom():m_occs(nullptr) {}
eq_occurs * m_eqs;
bit_atom():m_occs(nullptr), m_eqs(nullptr) {}
~bit_atom() override {}
bool is_bit() const override { return true; }
var_pos_it begin() const { return var_pos_it(m_occs); }
var_pos_it end() const { return var_pos_it(nullptr); }
bool is_fresh() const { return !m_occs && !m_eqs; }
class eqs_iterator {
bit_atom const& a;
public:
eqs_iterator(bit_atom const& a):a(a) {}
eq_occurs_it begin() const { return eq_occurs_it(a.m_eqs); }
eq_occurs_it end() const { return eq_occurs_it(nullptr); }
};
eqs_iterator eqs() const { return eqs_iterator(*this); }
};
struct def_atom : public atom {
@ -142,8 +183,17 @@ namespace bv {
bool is_bit() const override { return false; }
};
struct propagation_item {
var_pos m_vp { var_pos(0, 0) };
bit_atom* m_atom{ nullptr };
explicit propagation_item(bit_atom* a) : m_atom(a) {}
explicit propagation_item(var_pos const& vp) : m_vp(vp) {}
};
class bit_trail;
class add_var_pos_trail;
class add_eq_occurs_trail;
class mk_atom_trail;
class bit_occs_trail;
typedef ptr_vector<atom> bool_var2atom;
@ -160,15 +210,16 @@ namespace bv {
vector<zero_one_bits> m_zero_one_bits; // per var, see comment in the struct zero_one_bit
bool_var2atom m_bool_var2atom;
value2var m_fixed_var_table;
mutable vector<rational> m_power2;
literal_vector m_tmp_literals;
svector<var_pos> m_prop_queue;
unsigned_vector m_prop_queue_lim;
unsigned m_prop_queue_head { 0 };
mutable vector<rational> m_power2;
literal_vector m_tmp_literals;
svector<propagation_item> m_prop_queue;
unsigned_vector m_prop_queue_lim;
unsigned m_prop_queue_head { 0 };
sat::solver* m_solver;
sat::solver& s() { return *m_solver; }
sat::solver const& s() const { return *m_solver; }
// internalize
void insert_bv2a(bool_var bv, atom * a) { m_bool_var2atom.setx(bv, a, 0); }
@ -191,6 +242,8 @@ namespace bv {
void register_true_false_bit(theory_var v, unsigned i);
void add_bit(theory_var v, sat::literal lit);
bit_atom* mk_bit_atom(sat::bool_var bv);
void eq_internalized(sat::bool_var b, unsigned idx, theory_var v1, theory_var v2, euf::enode* n);
void set_bit_eh(theory_var v, literal l, unsigned idx);
void init_bits(expr* e, expr_ref_vector const & bits);
void mk_bits(theory_var v);
@ -227,10 +280,12 @@ namespace bv {
bool merge_zero_one_bits(theory_var r1, theory_var r2);
void assign_bit(literal consequent, theory_var v1, theory_var v2, unsigned idx, literal antecedent, bool propagate_eqc);
void propagate_bits(var_pos entry);
void propagate_eq_occurs(eq_occurs const& occ);
numeral const& power2(unsigned i) const;
// invariants
bool check_zero_one_bits(theory_var v);
void check_missing_propagation() const;
void validate_atoms() const;
public:
@ -282,6 +337,7 @@ namespace bv {
bool to_formulas(std::function<expr_ref(sat::literal)>& l2e, expr_ref_vector& fmls) override { return false; }
sat::literal internalize(expr* e, bool sign, bool root, bool learned) override;
void internalize(expr* e, bool redundant) override;
void eq_internalized(euf::enode* n) override;
euf::theory_var mk_var(euf::enode* n) override;
void apply_sort_cnstr(euf::enode * n, sort * s) override;