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prepare char utilities as a stand-alone theory

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This commit is contained in:
Nikolaj Bjorner 2021-01-26 10:34:03 -08:00
parent 785fab74f4
commit 31b7ad3012
6 changed files with 137 additions and 107 deletions
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1
src/model/seq_factory.h
View file

@ -20,6 +20,7 @@ Revision History:
#include "ast/seq_decl_plugin.h"
#include "model/model_core.h"
#include "model/value_factory.h"
class seq_factory : public value_factory {
typedef hashtable<symbol, symbol_hash_proc, symbol_eq_proc> symbol_set;

2
src/smt/CMakeLists.txt
View file

@ -17,7 +17,6 @@ z3_add_component(smt
seq_offset_eq.cpp
seq_regex.cpp
seq_skolem.cpp
seq_char.cpp
smt_almost_cg_table.cpp
smt_arith_value.cpp
smt_case_split_queue.cpp
@ -61,6 +60,7 @@ z3_add_component(smt
theory_array.cpp
theory_array_full.cpp
theory_bv.cpp
theory_char.cpp
theory_datatype.cpp
theory_dense_diff_logic.cpp
theory_diff_logic.cpp

191
src/smt/seq_char.cpp → src/smt/theory_char.cpp
View file

@ -16,16 +16,16 @@ Author:
--*/
#include "ast/bv_decl_plugin.h"
#include "smt/seq_char.h"
#include "smt/theory_char.h"
#include "smt/smt_context.h"
#include "smt/smt_model_generator.h"
namespace smt {
seq_char::seq_char(theory& th):
th(th),
m(th.get_manager()),
theory_char::theory_char(context& ctx, family_id fid):
theory(ctx, fid),
seq(m),
m_bb(m, ctx().get_fparams())
m_bb(m, ctx.get_fparams())
{
bv_util bv(m);
sort_ref b8(bv.mk_sort(8), m);
@ -33,11 +33,11 @@ namespace smt {
m_bits2char = symbol("bits2char");
}
struct seq_char::reset_bits : public trail<context> {
seq_char& s;
struct theory_char::reset_bits : public trail<context> {
theory_char& s;
unsigned idx;
reset_bits(seq_char& s, unsigned idx):
reset_bits(theory_char& s, unsigned idx):
s(s),
idx(idx)
{}
@ -48,10 +48,32 @@ namespace smt {
}
};
bool seq_char::has_bits(theory_var v) const {
bool theory_char::has_bits(theory_var v) const {
return (m_bits.size() > (unsigned)v) && !m_bits[v].empty();
}
bool theory_char::internalize_atom(app * term, bool gate_ctx) {
for (auto arg : *term)
mk_var(ensure_enode(arg));
bool_var bv = ctx.mk_bool_var(term);
ctx.set_var_theory(bv, get_id());
ctx.mark_as_relevant(bv);
if (seq.is_char_le(term))
internalize_le(literal(bv, false), term);
return true;
}
bool theory_char::internalize_term(app * term) {
for (auto arg : *term)
mk_var(ensure_enode(arg));
theory_var v = mk_var(ensure_enode(term));
unsigned c = 0;
if (seq.is_const_char(term, c))
new_const_char(v, c);
return true;
}
/**
* Initialize bits associated with theory variable v.
* add also the equality bits2char(char2bit(e, 0),..., char2bit(e, 15)) = e
@ -62,17 +84,17 @@ namespace smt {
* independently and adds Ackerman axioms on demand.
*/
void seq_char::init_bits(theory_var v) {
void theory_char::init_bits(theory_var v) {
if (has_bits(v))
return;
expr* e = th.get_expr(v);
expr* e = get_expr(v);
m_bits.reserve(v + 1);
auto& bits = m_bits[v];
while ((unsigned) v >= m_ebits.size())
m_ebits.push_back(expr_ref_vector(m));
ctx().push_trail(reset_bits(*this, v));
ctx.push_trail(reset_bits(*this, v));
auto& ebits = m_ebits[v];
SASSERT(ebits.empty());
@ -80,96 +102,96 @@ namespace smt {
if (is_bits2char) {
for (expr* arg : *to_app(e)) {
ebits.push_back(arg);
bits.push_back(literal(ctx().get_bool_var(arg)));
bits.push_back(literal(ctx.get_bool_var(arg)));
}
}
else {
for (unsigned i = 0; i < seq.num_bits(); ++i)
ebits.push_back(seq.mk_char_bit(e, i));
ctx().internalize(ebits.c_ptr(), ebits.size(), true);
ctx.internalize(ebits.c_ptr(), ebits.size(), true);
for (expr* arg : ebits)
bits.push_back(literal(ctx().get_bool_var(arg)));
bits.push_back(literal(ctx.get_bool_var(arg)));
for (literal bit : bits)
ctx().mark_as_relevant(bit);
ctx.mark_as_relevant(bit);
expr_ref bits2char(seq.mk_skolem(m_bits2char, ebits.size(), ebits.c_ptr(), m.get_sort(e)), m);
ctx().mark_as_relevant(bits2char.get());
enode* n1 = th.ensure_enode(e);
enode* n2 = th.ensure_enode(bits2char);
ctx.mark_as_relevant(bits2char.get());
enode* n1 = ensure_enode(e);
enode* n2 = ensure_enode(bits2char);
justification* j =
ctx().mk_justification(
ext_theory_eq_propagation_justification(th.get_id(), ctx().get_region(), n1, n2));
ctx().assign_eq(n1, n2, eq_justification(j));
ctx.mk_justification(
ext_theory_eq_propagation_justification(get_id(), ctx.get_region(), n1, n2));
ctx.assign_eq(n1, n2, eq_justification(j));
}
++m_stats.m_num_blast;
}
void seq_char::internalize_le(literal lit, app* term) {
void theory_char::internalize_le(literal lit, app* term) {
expr* x = nullptr, *y = nullptr;
VERIFY(seq.is_char_le(term, x, y));
theory_var v1 = ctx().get_enode(x)->get_th_var(th.get_id());
theory_var v2 = ctx().get_enode(y)->get_th_var(th.get_id());
theory_var v1 = ctx.get_enode(x)->get_th_var(get_id());
theory_var v2 = ctx.get_enode(y)->get_th_var(get_id());
init_bits(v1);
init_bits(v2);
auto const& b1 = get_ebits(v1);
auto const& b2 = get_ebits(v2);
expr_ref e(m);
m_bb.mk_ule(b1.size(), b1.c_ptr(), b2.c_ptr(), e);
literal le = th.mk_literal(e);
ctx().mark_as_relevant(le);
ctx().mk_th_axiom(th.get_id(), ~lit, le);
ctx().mk_th_axiom(th.get_id(), lit, ~le);
literal le = mk_literal(e);
ctx.mark_as_relevant(le);
ctx.mk_th_axiom(get_id(), ~lit, le);
ctx.mk_th_axiom(get_id(), lit, ~le);
}
literal_vector const& seq_char::get_bits(theory_var v) {
literal_vector const& theory_char::get_bits(theory_var v) {
init_bits(v);
return m_bits[v];
}
expr_ref_vector const& seq_char::get_ebits(theory_var v) {
expr_ref_vector const& theory_char::get_ebits(theory_var v) {
init_bits(v);
return m_ebits[v];
}
// = on characters
void seq_char::new_eq_eh(theory_var v, theory_var w) {
void theory_char::new_eq_eh(theory_var v, theory_var w) {
if (has_bits(v) && has_bits(w)) {
auto& a = get_bits(v);
auto& b = get_bits(w);
literal _eq = null_literal;
auto eq = [&]() {
if (_eq == null_literal) {
_eq = th.mk_literal(m.mk_eq(th.get_expr(v), th.get_expr(w)));
ctx().mark_as_relevant(_eq);
_eq = mk_literal(m.mk_eq(get_expr(v), get_expr(w)));
ctx.mark_as_relevant(_eq);
}
return _eq;
};
for (unsigned i = a.size(); i-- > 0; ) {
lbool v1 = ctx().get_assignment(a[i]);
lbool v2 = ctx().get_assignment(b[i]);
lbool v1 = ctx.get_assignment(a[i]);
lbool v2 = ctx.get_assignment(b[i]);
if (v1 != l_undef && v2 != l_undef && v1 != v2) {
enforce_ackerman(v, w);
return;
}
if (v1 == l_true)
ctx().mk_th_axiom(th.get_id(), ~eq(), ~a[i], b[i]);
ctx.mk_th_axiom(get_id(), ~eq(), ~a[i], b[i]);
if (v1 == l_false)
ctx().mk_th_axiom(th.get_id(), ~eq(), a[i], ~b[i]);
ctx.mk_th_axiom(get_id(), ~eq(), a[i], ~b[i]);
if (v2 == l_true)
ctx().mk_th_axiom(th.get_id(), ~eq(), a[i], ~b[i]);
ctx.mk_th_axiom(get_id(), ~eq(), a[i], ~b[i]);
if (v2 == l_false)
ctx().mk_th_axiom(th.get_id(), ~eq(), ~a[i], b[i]);
ctx.mk_th_axiom(get_id(), ~eq(), ~a[i], b[i]);
}
}
}
// != on characters
void seq_char::new_diseq_eh(theory_var v, theory_var w) {
void theory_char::new_diseq_eh(theory_var v, theory_var w) {
if (has_bits(v) && has_bits(w)) {
auto& a = get_bits(v);
auto& b = get_bits(w);
for (unsigned i = a.size(); i-- > 0; ) {
lbool v1 = ctx().get_assignment(a[i]);
lbool v2 = ctx().get_assignment(b[i]);
lbool v1 = ctx.get_assignment(a[i]);
lbool v2 = ctx.get_assignment(b[i]);
if (v1 == l_undef || v2 == l_undef || v1 != v2)
return;
}
@ -177,11 +199,11 @@ namespace smt {
}
}
void seq_char::new_const_char(theory_var v, unsigned c) {
void theory_char::new_const_char(theory_var v, unsigned c) {
auto& bits = get_bits(v);
for (auto b : bits) {
bool bit = (0 != (c & 1));
ctx().assign(bit ? b : ~b, nullptr);
ctx.assign(bit ? b : ~b, nullptr);
c >>= 1;
}
}
@ -192,22 +214,22 @@ namespace smt {
* Enforce that values are within max_char.
* 2. Assign values to characters that haven't been assigned.
*/
bool seq_char::final_check() {
bool theory_char::final_check() {
m_var2value.reset();
m_var2value.resize(th.get_num_vars(), UINT_MAX);
m_var2value.resize(get_num_vars(), UINT_MAX);
m_value2var.reset();
// extract the initial set of constants.
uint_set values;
unsigned c = 0, d = 0;
for (unsigned v = th.get_num_vars(); v-- > 0; ) {
expr* e = th.get_expr(v);
for (unsigned v = get_num_vars(); v-- > 0; ) {
expr* e = get_expr(v);
if (seq.is_char(e) && m_var2value[v] == UINT_MAX && get_value(v, c)) {
CTRACE("seq", seq.is_char(e), tout << mk_pp(e, m) << " root: " << th.get_enode(v)->is_root() << " is_value: " << get_value(v, c) << "\n";);
enode* r = th.get_enode(v)->get_root();
CTRACE("seq", seq.is_char(e), tout << mk_pp(e, m) << " root: " << get_enode(v)->is_root() << " is_value: " << get_value(v, c) << "\n";);
enode* r = get_enode(v)->get_root();
m_value2var.reserve(c + 1, null_theory_var);
theory_var u = m_value2var[c];
if (u != null_theory_var && r != th.get_enode(u)->get_root()) {
if (u != null_theory_var && r != get_enode(u)->get_root()) {
enforce_ackerman(u, v);
return false;
}
@ -216,7 +238,7 @@ namespace smt {
return false;
}
for (enode* n : *r) {
u = n->get_th_var(th.get_id());
u = n->get_th_var(get_id());
if (u == null_theory_var)
continue;
if (get_value(u, d) && d != c) {
@ -231,9 +253,9 @@ namespace smt {
}
// assign values to other unassigned nodes
c = 'a';
for (unsigned v = th.get_num_vars(); v-- > 0; ) {
expr* e = th.get_expr(v);
c = 'A';
for (unsigned v = get_num_vars(); v-- > 0; ) {
expr* e = get_expr(v);
if (seq.is_char(e) && m_var2value[v] == UINT_MAX) {
d = c;
while (values.contains(c)) {
@ -244,8 +266,8 @@ namespace smt {
}
}
TRACE("seq", tout << "fresh: " << mk_pp(e, m) << " := " << c << "\n";);
for (enode* n : *th.get_enode(v))
m_var2value[n->get_th_var(th.get_id())] = c;
for (enode* n : *get_enode(v))
m_var2value[n->get_th_var(get_id())] = c;
m_value2var.reserve(c + 1, null_theory_var);
m_value2var[c] = v;
values.insert(c);
@ -254,35 +276,35 @@ namespace smt {
return true;
}
void seq_char::enforce_bits() {
void theory_char::enforce_bits() {
TRACE("seq", tout << "enforce bits\n";);
for (unsigned v = th.get_num_vars(); v-- > 0; ) {
expr* e = th.get_expr(v);
if (seq.is_char(e) && th.get_enode(v)->is_root() && !has_bits(v))
for (unsigned v = get_num_vars(); v-- > 0; ) {
expr* e = get_expr(v);
if (seq.is_char(e) && get_enode(v)->is_root() && !has_bits(v))
init_bits(v);
}
}
void seq_char::enforce_value_bound(theory_var v) {
void theory_char::enforce_value_bound(theory_var v) {
TRACE("seq", tout << "enforce bound " << v << "\n";);
enode* n = th.ensure_enode(seq.mk_char(seq.max_char()));
theory_var w = n->get_th_var(th.get_id());
enode* n = ensure_enode(seq.mk_char(seq.max_char()));
theory_var w = n->get_th_var(get_id());
SASSERT(has_bits(w));
init_bits(v);
auto const& mbits = get_ebits(w);
auto const& bits = get_ebits(v);
expr_ref le(m);
m_bb.mk_ule(bits.size(), bits.c_ptr(), mbits.c_ptr(), le);
ctx().assign(th.mk_literal(le), nullptr);
ctx.assign(mk_literal(le), nullptr);
++m_stats.m_num_bounds;
}
void seq_char::enforce_ackerman(theory_var v, theory_var w) {
void theory_char::enforce_ackerman(theory_var v, theory_var w) {
if (v > w)
std::swap(v, w);
TRACE("seq", tout << "enforce ackerman " << v << " " << w << "\n";);
literal eq = th.mk_literal(m.mk_eq(th.get_expr(v), th.get_expr(w)));
ctx().mark_as_relevant(eq);
literal eq = mk_literal(m.mk_eq(get_expr(v), get_expr(w)));
ctx.mark_as_relevant(eq);
literal_vector lits;
init_bits(v);
init_bits(w);
@ -290,36 +312,49 @@ namespace smt {
auto& b = get_ebits(w);
for (unsigned i = a.size(); i-- > 0; ) {
// eq => a = b
literal beq = th.mk_eq(a[i], b[i], false);
literal beq = mk_eq(a[i], b[i], false);
lits.push_back(~beq);
ctx().mark_as_relevant(beq);
ctx().mk_th_axiom(th.get_id(), ~eq, beq);
ctx.mark_as_relevant(beq);
ctx.mk_th_axiom(get_id(), ~eq, beq);
}
// a = b => eq
lits.push_back(eq);
ctx().mk_th_axiom(th.get_id(), lits.size(), lits.c_ptr());
ctx.mk_th_axiom(get_id(), lits.size(), lits.c_ptr());
++m_stats.m_num_ackerman;
}
unsigned seq_char::get_value(theory_var v) {
unsigned theory_char::get_value(theory_var v) {
return m_var2value[v];
}
bool seq_char::get_value(theory_var v, unsigned& c) {
bool theory_char::get_value(theory_var v, unsigned& c) {
if (!has_bits(v))
return false;
auto const & b = get_bits(v);
c = 0;
unsigned p = 1;
for (literal lit : b) {
if (ctx().get_assignment(lit) == l_true)
if (ctx.get_assignment(lit) == l_true)
c += p;
p *= 2;
}
return true;
}
void seq_char::collect_statistics(::statistics& st) const {
// TBD: seq_factory needs to be replaced by a "char_factory" in the case where theory_char is
// a stand-alone theory.
void theory_char::init_model(model_generator & mg) {
m_factory = alloc(seq_factory, get_manager(), get_family_id(), mg.get_model());
}
model_value_proc * theory_char::mk_value(enode * n, model_generator & mg) {
unsigned ch = get_value(n->get_th_var(get_id()));
app* val = seq.str.mk_char(ch);
m_factory->add_trail(val);
return alloc(expr_wrapper_proc, val);
}
void theory_char::collect_statistics(::statistics& st) const {
st.update("seq char ackerman", m_stats.m_num_ackerman);
st.update("seq char bounds", m_stats.m_num_bounds);
st.update("seq char2bit", m_stats.m_num_blast);

43
src/smt/seq_char.h → src/smt/theory_char.h
View file

@ -19,12 +19,12 @@ Author:
#include "ast/seq_decl_plugin.h"
#include "ast/bv_decl_plugin.h"
#include "ast/rewriter/bit_blaster/bit_blaster.h"
#include "model/seq_factory.h"
#include "smt/smt_theory.h"
namespace smt {
class seq_char {
class theory_char : public theory {
struct stats {
unsigned m_num_ackerman;
@ -34,8 +34,6 @@ namespace smt {
void reset() { memset(this, 0, sizeof(*this)); }
};
theory& th;
ast_manager& m;
seq_util seq;
vector<literal_vector> m_bits;
vector<expr_ref_vector> m_ebits;
@ -45,10 +43,10 @@ namespace smt {
bit_blaster m_bb;
stats m_stats;
symbol m_bits2char;
seq_factory* m_factory { nullptr };
struct reset_bits;
context& ctx() const { return th.get_context(); }
literal_vector const& get_bits(theory_var v);
@ -68,33 +66,30 @@ namespace smt {
public:
seq_char(theory& th);
theory_char(context& ctx, family_id fid);
void new_eq_eh(theory_var v1, theory_var v2) override;
void new_diseq_eh(theory_var v1, theory_var v2) override;
theory * mk_fresh(context * new_ctx) override { return alloc(theory_char, *new_ctx, get_family_id()); }
bool internalize_atom(app * atom, bool gate_ctx) override;
bool internalize_term(app * term) override;
void display(std::ostream& out) const override {}
final_check_status final_check_eh() override { return final_check() ? FC_DONE : FC_CONTINUE; }
void init_model(model_generator & mg) override;
model_value_proc * mk_value(enode * n, model_generator & mg) override;
void collect_statistics(::statistics& st) const override;
// Methods exposed when theory_char is a sub-theory of seq and not a stand-alone theory
// ensure coherence for character codes and equalities of shared symbols.
bool enabled() const { return m_enabled; }
bool final_check();
// <= atomic constraints on characters
void assign_le(theory_var v1, theory_var v2, literal lit);
// < atomic constraint on characters
void assign_lt(theory_var v1, theory_var v2, literal lit);
void new_const_char(theory_var v, unsigned c);
// = on characters
void new_eq_eh(theory_var v1, theory_var v2);
// != on characters
void new_diseq_eh(theory_var v1, theory_var v2);
// ensure coherence for character codes and equalities of shared symbols.
bool final_check();
unsigned get_value(theory_var v);
void internalize_le(literal lit, app* term);
void collect_statistics(::statistics& st) const;
void internalize_le(literal lit, app* term);
};
}

3
src/smt/theory_seq.cpp
View file

@ -272,7 +272,7 @@ theory_seq::theory_seq(context& ctx):
m_autil(m),
m_sk(m, m_rewrite),
m_ax(*this, m_rewrite),
m_char(*this),
m_char(ctx, get_family_id()),
m_regex(*this),
m_arith_value(m),
m_trail_stack(*this),
@ -1812,7 +1812,6 @@ void theory_seq::init_model(model_generator & mg) {
}
}
class theory_seq::seq_value_proc : public model_value_proc {
enum source_t { unit_source, int_source, string_source };
theory_seq& th;

4
src/smt/theory_seq.h
View file

@ -28,10 +28,10 @@ Revision History:
#include "util/obj_ref_hashtable.h"
#include "smt/smt_theory.h"
#include "smt/smt_arith_value.h"
#include "smt/theory_char.h"
#include "smt/theory_seq_empty.h"
#include "smt/seq_skolem.h"
#include "smt/seq_axioms.h"
#include "smt/seq_char.h"
#include "smt/seq_regex.h"
#include "smt/seq_offset_eq.h"
@ -356,7 +356,7 @@ namespace smt {
arith_util m_autil;
seq_skolem m_sk;
seq_axioms m_ax;
seq_char m_char;
theory_char m_char;
seq_regex m_regex;
arith_value m_arith_value;
th_trail_stack m_trail_stack;