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seq

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2015-12-08 13:27:17 -08:00
parent 895d032996
commit 932a3a8387
2 changed files with 199 additions and 53 deletions
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197
src/smt/theory_seq.cpp
View file

@ -28,12 +28,13 @@ using namespace smt;
theory_seq::theory_seq(ast_manager& m):
theory(m.mk_family_id("seq")),
m(m),
m_dam(m_dep_array_value_manager, m_alloc),
m_rep(m),
m_eqs_head(0),
m_ineqs(m),
m_axioms(m),
m_axioms_head(0),
m_used(false),
m_incomplete(false),
m_rewrite(m),
m_util(m),
m_autil(m),
@ -41,59 +42,48 @@ theory_seq::theory_seq(ast_manager& m):
m_find(*this) {
m_lhs.push_back(expr_array());
m_rhs.push_back(expr_array());
m_deps.push_back(enode_pair_dependency_array());
}
final_check_status theory_seq::final_check_eh() {
context & ctx = get_context();
final_check_status st = check_ineqs();
if (st == FC_CONTINUE) {
if (!check_ineqs()) {
return FC_CONTINUE;
}
return m_used?FC_GIVEUP:FC_DONE;
if (simplify_and_solve_eqs()) {
return FC_CONTINUE;
}
if (m.size(m_lhs.back()) > 0) {
return FC_GIVEUP;
}
return m_incomplete?FC_GIVEUP:FC_DONE;
}
final_check_status theory_seq::check_ineqs() {
bool theory_seq::check_ineqs() {
context & ctx = get_context();
enode_pair_vector eqs;
for (unsigned i = 0; i < m_ineqs.size(); ++i) {
expr_ref a(m_ineqs[i].get(), m);
enode_pair_dependency* eqs = 0;
expr_ref b = canonize(a, eqs);
if (m.is_true(b)) {
ctx.internalize(a, false);
literal lit(ctx.get_literal(a));
ctx.mark_as_relevant(lit);
vector<enode_pair, false> _eqs;
m_dm.linearize(eqs, _eqs);
ctx.assign(
lit,
ctx.mk_justification(
ext_theory_propagation_justification(
get_id(), ctx.get_region(), 0, 0, eqs.size(), eqs.c_ptr(), lit)));
return FC_CONTINUE;
get_id(), ctx.get_region(), 0, 0, _eqs.size(), _eqs.c_ptr(), lit)));
return false;
}
}
return FC_DONE;
return true;
}
bool theory_seq::simplify_eqs() {
context & ctx = get_context();
bool simplified = false;
expr_array& lhs = m_lhs.back();
expr_array& rhs = m_rhs.back();
for (unsigned i = 0; !ctx.inconsistent() && i < m.size(lhs); ++i) {
if (simplify_eq(m.get(lhs, i), m.get(rhs, i), m_deps)) {
if (i + 1 != m.size(lhs)) {
m.set(lhs, i, m.get(lhs, m.size(lhs)-1));
m.set(rhs, i, m.get(rhs, m.size(rhs)-1));
--i;
simplified = true;
}
m.pop_back(lhs);
m.pop_back(rhs);
}
}
return simplified;
}
bool theory_seq::simplify_eq(expr* l, expr* r, enode_pair_vector& deps) {
bool theory_seq::simplify_eq(expr* l, expr* r, enode_pair_dependency* deps) {
context& ctx = get_context();
seq_rewriter rw(m);
expr_ref_vector lhs(m), rhs(m);
@ -107,11 +97,13 @@ bool theory_seq::simplify_eq(expr* l, expr* r, enode_pair_vector& deps) {
expr_ref a(m);
a = m.mk_eq(l, r);
literal lit(ctx.get_literal(a));
vector<enode_pair, false> _eqs;
m_dm.linearize(deps, _eqs);
ctx.assign(
~lit,
ctx.mk_justification(
ext_theory_propagation_justification(
get_id(), ctx.get_region(), 0, 0, deps.size(), deps.c_ptr(), ~lit)));
get_id(), ctx.get_region(), 0, 0, _eqs.size(), _eqs.c_ptr(), ~lit)));
return true;
}
if (lhs.size() == 1 && l == lhs[0].get() &&
@ -122,11 +114,96 @@ bool theory_seq::simplify_eq(expr* l, expr* r, enode_pair_vector& deps) {
for (unsigned i = 0; i < lhs.size(); ++i) {
m.push_back(m_lhs.back(), lhs[i].get());
m.push_back(m_rhs.back(), rhs[i].get());
// TBD m_deps.push_back(deps);
m_dam.push_back(m_deps.back(), deps);
}
return true;
}
bool theory_seq::solve_unit_eq(expr* l, expr* r, enode_pair_dependency* deps) {
expr_ref lh = canonize(l, deps);
expr_ref rh = canonize(r, deps);
if (is_var(lh) && !occurs(lh, rh)) {
add_solution(lh, rh, deps);
return true;
}
if (is_var(rh) && !occurs(rh, lh)) {
add_solution(rh, lh, deps);
return true;
}
// Use instead reference counts for dependencies to GC?
return false;
}
bool theory_seq::occurs(expr* a, expr* b) {
// TBD
return true;
}
bool theory_seq::is_var(expr* a) {
// TBD
return false;
}
void theory_seq::add_solution(expr* l, expr* r, enode_pair_dependency* deps) {
context& ctx = get_context();
// TBD: internalize lh, rh;
//
enode* n1 = ctx.get_enode(l);
enode* n2 = ctx.get_enode(r);
// TBD: add substitution l -> r
vector<enode_pair, false> _eqs;
m_dm.linearize(deps, _eqs);
// alloc?
ctx.assign_eq(n1, n2, eq_justification(
alloc(ext_theory_eq_propagation_justification,
get_id(), ctx.get_region(), 0, 0, _eqs.size(), _eqs.c_ptr(), n1, n2)));
}
bool theory_seq::simplify_eqs() {
return pre_process_eqs(true);
}
bool theory_seq::solve_basic_eqs() {
return pre_process_eqs(false);
}
bool theory_seq::pre_process_eqs(bool simplify_or_solve) {
context& ctx = get_context();
bool change = false;
expr_array& lhs = m_lhs.back();
expr_array& rhs = m_rhs.back();
enode_pair_dependency_array& deps = m_deps.back();
for (unsigned i = 0; !ctx.inconsistent() && i < m.size(lhs); ++i) {
if (simplify_or_solve?
simplify_eq(m.get(lhs, i), m.get(rhs, i), m_dam.get(deps, i)):
solve_unit_eq(m.get(lhs, i), m.get(rhs, i), m_dam.get(deps, i))) {
if (i + 1 != m.size(lhs)) {
m.set(lhs, i, m.get(lhs, m.size(lhs)-1));
m.set(rhs, i, m.get(rhs, m.size(rhs)-1));
m_dam.set(deps, i, m_dam.get(deps, m_dam.size(deps)-1));
--i;
change = true;
}
m.pop_back(lhs);
m.pop_back(rhs);
m_dam.pop_back(deps);
}
}
return change;
}
bool theory_seq::simplify_and_solve_eqs() {
context & ctx = get_context();
bool change = simplify_eqs();
while (!ctx.inconsistent() && solve_basic_eqs()) {
simplify_eqs();
change = true;
}
return change;
}
final_check_status theory_seq::add_axioms() {
for (unsigned i = 0; i < get_num_vars(); ++i) {
@ -140,7 +217,6 @@ bool theory_seq::internalize_atom(app* a, bool) {
}
bool theory_seq::internalize_term(app* term) {
m_used = true;
context & ctx = get_context();
unsigned num_args = term->get_num_args();
for (unsigned i = 0; i < num_args; i++) {
@ -159,11 +235,26 @@ bool theory_seq::internalize_term(app* term) {
theory_var v = mk_var(e);
ctx.attach_th_var(e, this, v);
}
if (!m_util.str.is_concat(term) &&
!m_util.str.is_string(term) &&
!m_util.str.is_suffix(term) &&
!m_util.str.is_prefix(term) &&
!m_util.str.is_contains(term)) {
set_incomplete(term);
}
// assert basic axioms
if (!m_used) { m_trail_stack.push(value_trail<theory_seq,bool>(m_used)); m_used = true; }
return true;
}
void theory_seq::set_incomplete(app* term) {
TRACE("seq", tout << "No support for: " << mk_pp(term, m) << "\n";);
if (!m_incomplete) {
m_trail_stack.push(value_trail<theory_seq,bool>(m_incomplete));
m_incomplete = true;
}
}
theory_var theory_seq::mk_var(enode* n) {
theory_var r = theory::mk_var(n);
VERIFY(r == m_find.mk_var());
@ -175,14 +266,13 @@ bool theory_seq::can_propagate() {
return m_axioms_head < m_axioms.size();
}
expr_ref theory_seq::canonize(expr* e, enode_pair_vector& eqs) {
eqs.reset();
expr_ref theory_seq::canonize(expr* e, enode_pair_dependency*& eqs) {
expr_ref result = expand(e, eqs);
m_rewrite(result);
return result;
}
expr_ref theory_seq::expand(expr* e, enode_pair_vector& eqs) {
expr_ref theory_seq::expand(expr* e, enode_pair_dependency*& eqs) {
context& ctx = get_context();
expr* e1, *e2;
SASSERT(ctx.e_internalized(e));
@ -191,27 +281,27 @@ expr_ref theory_seq::expand(expr* e, enode_pair_vector& eqs) {
do {
e = n->get_owner();
if (m_util.str.is_concat(e, e1, e2)) {
if (start != n) eqs.push_back(enode_pair(start, n));
add_dependency(eqs, start, n);
return expr_ref(m_util.str.mk_concat(expand(e1, eqs), expand(e2, eqs)), m);
}
if (m_util.str.is_empty(e) || m_util.str.is_string(e)) {
if (start != n) eqs.push_back(enode_pair(start, n));
add_dependency(eqs, start, n);
return expr_ref(e, m);
}
if (m.is_eq(e, e1, e2)) {
if (start != n) eqs.push_back(enode_pair(start, n));
add_dependency(eqs, start, n);
return expr_ref(m.mk_eq(expand(e1, eqs), expand(e2, eqs)), m);
}
if (m_util.str.is_prefix(e, e1, e2)) {
if (start != n) eqs.push_back(enode_pair(start, n));
add_dependency(eqs, start, n);
return expr_ref(m_util.str.mk_prefix(expand(e1, eqs), expand(e2, eqs)), m);
}
if (m_util.str.is_suffix(e, e1, e2)) {
if (start != n) eqs.push_back(enode_pair(start, n));
add_dependency(eqs, start, n);
return expr_ref(m_util.str.mk_suffix(expand(e1, eqs), expand(e2, eqs)), m);
}
if (m_util.str.is_contains(e, e1, e2)) {
if (start != n) eqs.push_back(enode_pair(start, n));
add_dependency(eqs, start, n);
return expr_ref(m_util.str.mk_contains(expand(e1, eqs), expand(e2, eqs)), m);
}
#if 0
@ -227,6 +317,20 @@ expr_ref theory_seq::expand(expr* e, enode_pair_vector& eqs) {
return expr_ref(n->get_root()->get_owner(), m);
}
void theory_seq::add_dependency(enode_pair_dependency*& dep, enode* a, enode* b) {
dep = join(dep, leaf(a, b));
}
theory_seq::enode_pair_dependency* theory_seq::join(enode_pair_dependency* a, enode_pair_dependency* b) {
if (!a) return b;
if (!b) return a;
return m_dm.mk_join(a, b);
}
theory_seq::enode_pair_dependency* theory_seq::leaf(enode* a, enode* b) {
return (a == b)?0:m_dm.mk_leaf(std::make_pair(a, b));
}
void theory_seq::propagate() {
context & ctx = get_context();
while (m_axioms_head < m_axioms.size() && !ctx.inconsistent()) {
@ -328,26 +432,33 @@ void theory_seq::new_diseq_eh(theory_var v1, theory_var v2) {
void theory_seq::push_scope_eh() {
theory::push_scope_eh();
m_dm.push_scope();
m_trail_stack.push_scope();
m_trail_stack.push(value_trail<theory_seq, unsigned>(m_axioms_head));
m_trail_stack.push(value_trail<theory_seq, unsigned>(m_eqs_head));
expr_array lhs, rhs;
enode_pair_dependency_array deps;
m.copy(m_lhs.back(), lhs);
m.copy(m_rhs.back(), rhs);
m_dam.copy(m_deps.back(), deps);
m_lhs.push_back(lhs);
m_rhs.push_back(rhs);
m_deps.push_back(deps);
}
void theory_seq::pop_scope_eh(unsigned num_scopes) {
m_trail_stack.pop_scope(num_scopes);
theory::pop_scope_eh(num_scopes);
theory::pop_scope_eh(num_scopes);
m_dm.pop_scope(num_scopes);
m_rep.resize(get_num_vars());
while (num_scopes > 0) {
--num_scopes;
m.del(m_lhs.back());
m.del(m_rhs.back());
m_dam.del(m_deps.back());
m_lhs.pop_back();
m_rhs.pop_back();
m_deps.pop_back();
}
}

55
src/smt/theory_seq.h
View file

@ -28,6 +28,22 @@ Revision History:
namespace smt {
class theory_seq : public theory {
struct config {
static const bool preserve_roots = true;
static const unsigned max_trail_sz = 16;
static const unsigned factor = 2;
typedef small_object_allocator allocator;
};
typedef scoped_dependency_manager<enode_pair> enode_pair_dependency_manager;
typedef enode_pair_dependency_manager::dependency enode_pair_dependency;
struct enode_pair_dependency_array_config : public config {
typedef enode_pair_dependency* value;
typedef dummy_value_manager<value> value_manager;
static const bool ref_count = false;
};
typedef parray_manager<enode_pair_dependency_array_config> enode_pair_dependency_array_manager;
typedef enode_pair_dependency_array_manager::ref enode_pair_dependency_array;
typedef union_find<theory_seq> th_union_find;
typedef trail_stack<theory_seq> th_trail_stack;
struct stats {
@ -35,17 +51,23 @@ namespace smt {
void reset() { memset(this, 0, sizeof(stats)); }
unsigned m_num_splits;
};
ast_manager& m;
expr_ref_vector m_rep; // unification representative.
vector<expr_array> m_lhs, m_rhs; // persistent sets of equalities.
unsigned m_eqs_head; // index of unprocessed equation.
enode_pair_vector m_deps; // TBD - convert to dependency structure.
ast_manager& m;
small_object_allocator m_alloc;
enode_pair_dependency_array_config::value_manager m_dep_array_value_manager;
enode_pair_dependency_manager m_dm;
enode_pair_dependency_array_manager m_dam;
expr_ref_vector m_rep; // unification representative.
vector<expr_array> m_lhs, m_rhs; // persistent sets of equalities.
vector<enode_pair_dependency_array> m_deps;
unsigned m_eqs_head; // index of unprocessed equation. deprecate
expr_ref_vector m_ineqs; // inequalities to check
expr_ref_vector m_axioms;
unsigned m_axioms_head;
bool m_used; // deprecate
bool m_incomplete;
th_rewriter m_rewrite;
seq_util m_util;
arith_util m_autil;
@ -69,18 +91,31 @@ namespace smt {
virtual char const * get_name() const { return "seq"; }
virtual theory_var mk_var(enode* n);
final_check_status check_ineqs();
bool check_ineqs();
bool pre_process_eqs(bool simplify_or_solve);
bool simplify_eqs();
bool simplify_eq(expr* l, expr* r, enode_pair_vector& deps);
bool simplify_eq(expr* l, expr* r, enode_pair_dependency* deps);
bool solve_unit_eq(expr* l, expr* r, enode_pair_dependency* deps);
bool solve_basic_eqs();
bool simplify_and_solve_eqs();
bool occurs(expr* a, expr* b);
bool is_var(expr* b);
void add_solution(expr* l, expr* r, enode_pair_dependency* dep);
final_check_status add_axioms();
void assert_axiom(expr_ref& e);
void create_axiom(expr_ref& e);
expr_ref canonize(expr* e, enode_pair_vector& eqs);
expr_ref expand(expr* e, enode_pair_vector& eqs);
expr_ref canonize(expr* e, enode_pair_dependency*& eqs);
expr_ref expand(expr* e, enode_pair_dependency*& eqs);
void add_dependency(enode_pair_dependency*& dep, enode* a, enode* b);
enode_pair_dependency* leaf(enode* a, enode* b);
enode_pair_dependency* join(enode_pair_dependency* a, enode_pair_dependency* b);
void propagate_eq(bool_var v, expr* e1, expr* e2);
expr_ref mk_skolem(char const* name, expr* e1, expr* e2);
void set_incomplete(app* term);
public:
theory_seq(ast_manager& m);
virtual void init_model(model_generator & mg) {