diff --git a/src/api/python/z3.py b/src/api/python/z3.py index 27bfa6590..f5b2a1e6e 100644 --- a/src/api/python/z3.py +++ b/src/api/python/z3.py @@ -5693,8 +5693,6 @@ class Statistics: >>> s.check() sat >>> st = s.statistics() - >>> st.keys() - ['nlsat propagations', 'nlsat stages', 'rlimit count', 'max memory', 'memory', 'num allocs'] """ return [Z3_stats_get_key(self.ctx.ref(), self.stats, idx) for idx in range(len(self))] @@ -5730,8 +5728,6 @@ class Statistics: >>> s.check() sat >>> st = s.statistics() - >>> st.keys() - ['nlsat propagations', 'nlsat stages', 'rlimit count', 'max memory', 'memory', 'num allocs'] >>> st.nlsat_propagations 2 >>> st.nlsat_stages diff --git a/src/ast/rewriter/seq_rewriter.cpp b/src/ast/rewriter/seq_rewriter.cpp index 1eaf6b42b..d61ccc4a5 100644 --- a/src/ast/rewriter/seq_rewriter.cpp +++ b/src/ast/rewriter/seq_rewriter.cpp @@ -520,6 +520,7 @@ br_status seq_rewriter::mk_eq_core(expr * l, expr * r, expr_ref & result) { bool seq_rewriter::reduce_eq(expr* l, expr* r, expr_ref_vector& lhs, expr_ref_vector& rhs) { expr* a, *b; + zstring s; bool change = false; expr_ref_vector trail(m()); m_lhs.reset(); @@ -528,23 +529,55 @@ bool seq_rewriter::reduce_eq(expr* l, expr* r, expr_ref_vector& lhs, expr_ref_ve m_util.str.get_concat(r, m_rhs); // solve from back - while (!m_lhs.empty() && !m_rhs.empty()) { - if (m_lhs.back() == m_rhs.back()) { + while (true) { + while (!m_rhs.empty() && m_util.str.is_empty(m_rhs.back())) { + m_rhs.pop_back(); + change = true; + } + while (!m_lhs.empty() && m_util.str.is_empty(m_lhs.back())) { + m_lhs.pop_back(); + change = true; + } + if (m_lhs.empty() || m_rhs.empty()) { + break; + } + expr* l = m_lhs.back(); + expr* r = m_rhs.back(); + if (m_util.str.is_unit(r) && m_util.str.is_string(l)) { + std::swap(l, r); + std::swap(m_lhs, m_rhs); + } + if (l == r) { m_lhs.pop_back(); m_rhs.pop_back(); } - else if(m_util.str.is_unit(m_lhs.back(), a) && - m_util.str.is_unit(m_rhs.back(), b)) { + else if(m_util.str.is_unit(l, a) && + m_util.str.is_unit(r, b)) { lhs.push_back(a); rhs.push_back(b); m_lhs.pop_back(); m_rhs.pop_back(); } - else if (!m_rhs.empty() && m_util.str.is_empty(m_rhs.back())) { - m_rhs.pop_back(); - } - else if (!m_lhs.empty() && m_util.str.is_empty(m_lhs.back())) { + else if (m_util.str.is_unit(l, a) && m_util.str.is_string(r, s)) { + SASSERT(s.length() > 0); + + unsigned ch = s[s.length()-1]; + SASSERT(s.num_bits() == m_butil.get_bv_size(a)); + expr_ref bv(m()); + + bv = m_butil.mk_numeral(ch, s.num_bits()); + SASSERT(m_butil.is_bv(a)); + lhs.push_back(bv); + rhs.push_back(a); m_lhs.pop_back(); + if (s.length() == 1) { + m_rhs.pop_back(); + } + else { + expr_ref s2(m_util.str.mk_string(s.extract(0, s.length()-2)), m()); + m_rhs[m_rhs.size()-1] = s2; + trail.push_back(s2); + } } else { break; @@ -554,23 +587,55 @@ bool seq_rewriter::reduce_eq(expr* l, expr* r, expr_ref_vector& lhs, expr_ref_ve // solve from front unsigned head1 = 0, head2 = 0; - while (head1 < m_lhs.size() && head2 < m_rhs.size()) { - if (m_lhs[head1] == m_rhs[head2]) { + while (true) { + while (head1 < m_lhs.size() && m_util.str.is_empty(m_lhs[head1])) { + ++head1; + } + while (head2 < m_rhs.size() && m_util.str.is_empty(m_rhs[head2])) { + ++head2; + } + if (head1 == m_lhs.size() || head2 == m_rhs.size()) { + break; + } + SASSERT(head1 < m_lhs.size() && head2 == m_rhs.size()); + + expr* l = m_lhs[head1]; + expr* r = m_rhs[head2]; + if (m_util.str.is_unit(r) && m_util.str.is_string(l)) { + std::swap(l, r); + std::swap(m_lhs, m_rhs); + } + if (l == r) { ++head1; ++head2; } - else if(m_util.str.is_unit(m_lhs[head1], a) && - m_util.str.is_unit(m_rhs[head2], b)) { + else if(m_util.str.is_unit(l, a) && + m_util.str.is_unit(r, b)) { lhs.push_back(a); rhs.push_back(b); ++head1; ++head2; } - else if (head1 < m_lhs.size() && m_util.str.is_empty(m_lhs[head1])) { - ++head1; - } - else if (head2 < m_rhs.size() && m_util.str.is_empty(m_rhs[head2])) { - ++head2; + else if (m_util.str.is_unit(l, a) && m_util.str.is_string(r, s)) { + SASSERT(s.length() > 0); + + unsigned ch = s[0]; + SASSERT(s.num_bits() == m_butil.get_bv_size(a)); + expr_ref bv(m()); + + bv = m_butil.mk_numeral(ch, s.num_bits()); + SASSERT(m_butil.is_bv(a)); + lhs.push_back(bv); + rhs.push_back(a); + m_lhs.pop_back(); + if (s.length() == 1) { + m_rhs.pop_back(); + } + else { + expr_ref s2(m_util.str.mk_string(s.extract(1, s.length()-1)), m()); + m_rhs[m_rhs.size()-1] = s2; + trail.push_back(s2); + } } else { break; diff --git a/src/ast/rewriter/seq_rewriter.h b/src/ast/rewriter/seq_rewriter.h index de3634a51..ffc8addd3 100644 --- a/src/ast/rewriter/seq_rewriter.h +++ b/src/ast/rewriter/seq_rewriter.h @@ -21,6 +21,7 @@ Notes: #include"seq_decl_plugin.h" #include"arith_decl_plugin.h" +#include"bv_decl_plugin.h" #include"rewriter_types.h" #include"params.h" #include"lbool.h" @@ -32,6 +33,7 @@ Notes: class seq_rewriter { seq_util m_util; arith_util m_autil; + bv_util m_butil; ptr_vector m_es, m_lhs, m_rhs; br_status mk_seq_concat(expr* a, expr* b, expr_ref& result); @@ -63,7 +65,7 @@ class seq_rewriter { public: seq_rewriter(ast_manager & m, params_ref const & p = params_ref()): - m_util(m), m_autil(m) { + m_util(m), m_autil(m), m_butil(m) { } ast_manager & m() const { return m_util.get_manager(); } family_id get_fid() const { return m_util.get_family_id(); } diff --git a/src/muz/base/dl_context.h b/src/muz/base/dl_context.h index e5639959b..f37169cac 100644 --- a/src/muz/base/dl_context.h +++ b/src/muz/base/dl_context.h @@ -487,9 +487,7 @@ namespace datalog { // ----------------------------------- bool canceled() { - if (m.limit().inc()) return true; - m_last_status = CANCELED; - return false; + return m.canceled() && (m_last_status = CANCELED, true); } void cleanup(); diff --git a/src/muz/rel/rel_context.cpp b/src/muz/rel/rel_context.cpp index 25af7d798..68bc25c27 100644 --- a/src/muz/rel/rel_context.cpp +++ b/src/muz/rel/rel_context.cpp @@ -151,6 +151,7 @@ namespace datalog { m_context.ensure_closed(); transform_rules(); if (m_context.canceled()) { + TRACE("dl", tout << "canceled\n";); result = l_undef; break; } @@ -191,6 +192,7 @@ namespace datalog { IF_VERBOSE(10, m_ectx.report_big_relations(1000, verbose_stream());); if (m_context.canceled()) { + TRACE("dl", tout << "canceled\n";); result = l_undef; break; } @@ -206,6 +208,7 @@ namespace datalog { } if (timeout_after_this_round) { m_context.set_status(TIMEOUT); + TRACE("dl", tout << "timeout\n";); result = l_undef; break; } @@ -272,6 +275,7 @@ namespace datalog { if (some_non_empty) { m_answer = mk_and(m, ans.size(), ans.c_ptr()); if (is_approx) { + TRACE("dl", tout << "approx\n";); res = l_undef; m_context.set_status(APPROX); } @@ -286,6 +290,7 @@ namespace datalog { m_answer = m.mk_false(); break; case l_undef: + TRACE("dl", tout << "saturation in undef\n";); break; } return res; @@ -367,6 +372,7 @@ namespace datalog { m_last_result_relation->to_formula(m_answer); if (!m_last_result_relation->is_precise()) { m_context.set_status(APPROX); + TRACE("dl", tout << "approx\n";); res = l_undef; } } diff --git a/src/smt/smt_setup.cpp b/src/smt/smt_setup.cpp index 8a40f9d7a..8ebfa2d71 100644 --- a/src/smt/smt_setup.cpp +++ b/src/smt/smt_setup.cpp @@ -815,7 +815,7 @@ namespace smt { } void setup::setup_seq() { - m_context.register_plugin(alloc(theory_seq, m_manager)); + m_context.register_plugin(alloc(theory_seq_empty, m_manager)); } void setup::setup_card() { diff --git a/src/smt/theory_seq.cpp b/src/smt/theory_seq.cpp index 67ab2cfe3..718e3fd70 100644 --- a/src/smt/theory_seq.cpp +++ b/src/smt/theory_seq.cpp @@ -27,6 +27,7 @@ Revision History: using namespace smt; void theory_seq::solution_map::update(expr* e, expr* r, enode_pair_dependency* d) { + m_cache.reset(); std::pair value; if (m_map.find(e, value)) { add_trail(DEL, e, value.first, value.second); @@ -47,21 +48,17 @@ void theory_seq::solution_map::add_trail(map_update op, expr* l, expr* r, enode_ expr* theory_seq::solution_map::find(expr* e, enode_pair_dependency*& d) { std::pair value; d = 0; - unsigned num_finds = 0; expr* result = e; while (m_map.find(result, value)) { d = m_dm.mk_join(d, value.second); result = value.first; - ++num_finds; - } - if (num_finds > 1) { // path compression for original key only. - update(e, result, d); } return result; } void theory_seq::solution_map::pop_scope(unsigned num_scopes) { if (num_scopes == 0) return; + m_cache.reset(); unsigned start = m_limit[m_limit.size() - num_scopes]; for (unsigned i = m_updates.size(); i > start; ) { --i; @@ -80,7 +77,7 @@ void theory_seq::solution_map::pop_scope(unsigned num_scopes) { } void theory_seq::solution_map::display(std::ostream& out) const { - map_t::iterator it = m_map.begin(), end = m_map.end(); + eqdep_map_t::iterator it = m_map.begin(), end = m_map.end(); for (; it != end; ++it) { out << mk_pp(it->m_key, m) << " |-> " << mk_pp(it->m_value.first, m) << "\n"; } @@ -125,10 +122,7 @@ void theory_seq::exclusion_table::display(std::ostream& out) const { 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_dm), - m_cache(m), - m_sort2len_fn(m), m_factory(0), m_ineqs(m), m_exclude(m), @@ -142,9 +136,6 @@ theory_seq::theory_seq(ast_manager& m): m_util(m), m_autil(m), m_trail_stack(*this) { - m_lhs.push_back(expr_array()); - m_rhs.push_back(expr_array()); - m_deps.push_back(enode_pair_dependency_array()); m_prefix_sym = "seq.prefix.suffix"; m_suffix_sym = "seq.suffix.prefix"; m_left_sym = "seq.left"; @@ -154,11 +145,6 @@ theory_seq::theory_seq(ast_manager& m): } theory_seq::~theory_seq() { - unsigned num_scopes = m_lhs.size()-1; - if (num_scopes > 0) pop_scope_eh(num_scopes); - m.del(m_lhs.back()); - m.del(m_rhs.back()); - m_dam.del(m_deps.back()); } @@ -183,10 +169,14 @@ final_check_status theory_seq::final_check_eh() { if (ctx.inconsistent()) { return FC_CONTINUE; } - if (m.size(m_lhs.back()) > 0 || m_incomplete) { - return FC_GIVEUP; + if (!check_length_coherence()) { + return FC_CONTINUE; } - return FC_DONE; + if (is_solved()) { + return FC_DONE; + } + + return FC_GIVEUP; } bool theory_seq::check_ineqs() { @@ -201,6 +191,9 @@ bool theory_seq::check_ineqs() { propagate_lit(eqs, ctx.get_literal(a)); return false; } + else if (!m.is_false(b)) { + TRACE("seq", tout << "equality is undetermined: " << mk_pp(a, m) << " " << b << "\n";); + } } return true; } @@ -208,18 +201,15 @@ bool theory_seq::check_ineqs() { bool theory_seq::branch_variable() { context& ctx = get_context(); TRACE("seq", ctx.display(tout);); - expr_array& lhs = m_lhs.back(); - expr_array& rhs = m_rhs.back(); - unsigned sz = m.size(lhs); + unsigned sz = m_eqs.size(); ptr_vector ls, rs; for (unsigned i = 0; i < sz; ++i) { unsigned k = (i + m_branch_variable_head) % sz; - expr* l = m.get(lhs, k); - expr* r = m.get(rhs, k); - TRACE("seq", tout << mk_pp(l, m) << " = " << mk_pp(r, m) << "\n";); + eq e = m_eqs[k]; + TRACE("seq", tout << e.m_lhs << " = " << e.m_rhs << "\n";); ls.reset(); rs.reset(); - m_util.str.get_concat(l, ls); - m_util.str.get_concat(r, rs); + m_util.str.get_concat(e.m_lhs, ls); + m_util.str.get_concat(e.m_rhs, rs); if (!ls.empty() && find_branch_candidate(ls[0], rs)) { m_branch_variable_head = k; @@ -290,13 +280,90 @@ bool theory_seq::split_variable() { return false; } +bool theory_seq::check_length_coherence() { + if (!m_has_length) return true; + return false; + context& ctx = get_context(); + bool coherent = true; + for (unsigned i = 0; i < m_eqs.size(); ++i) { + m_eqs[i].m_dep; + expr_ref v1(m), v2(m), l(m_eqs[i].m_lhs), r(m_eqs[i].m_rhs); + expr_ref len1(m_util.str.mk_length(l), m); + expr_ref len2(m_util.str.mk_length(r), m); + if (!ctx.e_internalized(len1)) ctx.internalize(len1, false); + if (!ctx.e_internalized(len2)) ctx.internalize(len2, false); + enode* n1 = get_enode(len1); + enode* n2 = get_enode(len2); + if (n1->get_root() != n2->get_root()) { + propagate_eq(m_eqs[i].m_dep, n1, n2); + coherent = false; + } + } + // each variable that canonizes to itself can have length 0. + unsigned sz = get_num_vars(); + for (unsigned i = 0; i < sz; ++i) { + enode* n = get_enode(i); + expr* e = n->get_owner(); + if (!m_util.is_seq(e)) { + continue; + } + // extend length of variables. + enode_pair_dependency* dep = 0; + if (is_var(m_rep.find(e, dep))) { + expr_ref emp(m_util.str.mk_empty(m.get_sort(e)), m); + if (!assume_equality(e, emp)) { + // e = emp \/ e = head*tail & head = unit(v) + // add_axiom(mk_eq(e, emp, false), mk_eq(e, m_util.mk_concat(x, y), e)); + // add_axiom(mk_eq(e, emp, false), mk_eq(x, unit_x)); + } + coherent = false; + } + } + + return coherent; +} + +bool theory_seq::check_ineq_coherence() { + bool all_false = true; + for (unsigned i = 0; all_false && i < m_ineqs.size(); ++i) { + expr* a = m_ineqs[i].get(); + enode_pair_dependency* eqs = 0; + expr_ref b = canonize(a, eqs); + all_false = m.is_false(b); + if (all_false) { + TRACE("seq", tout << "equality is undetermined: " << mk_pp(a, m) << " " << b << "\n";); + } + } + return all_false; +} + +/* + - Eqs = 0 + - Diseqs evaluate to false + - lengths are coherent. +*/ + +bool theory_seq::is_solved() { + if (!m_eqs.empty()) { + return false; + } + if (!check_ineq_coherence()) { + return false; + } + + SASSERT(check_length_coherence()); + + return true; + +} + void theory_seq::propagate_lit(enode_pair_dependency* dep, literal lit) { context& ctx = get_context(); ctx.mark_as_relevant(lit); vector _eqs; m_dm.linearize(dep, _eqs); TRACE("seq", ctx.display_detailed_literal(tout, lit); - tout << " <-\n"; display_deps(tout, dep);); + tout << " <- "; display_deps(tout, dep);); justification* js = ctx.mk_justification( ext_theory_propagation_justification( @@ -321,7 +388,7 @@ void theory_seq::propagate_eq(enode_pair_dependency* dep, enode* n1, enode* n2) vector _eqs; m_dm.linearize(dep, _eqs); TRACE("seq", - tout << mk_pp(n1->get_owner(), m) << " " << mk_pp(n2->get_owner(), m) << " <- "; + tout << mk_pp(n1->get_owner(), m) << " = " << mk_pp(n2->get_owner(), m) << " <- "; display_deps(tout, dep); ); @@ -351,14 +418,12 @@ bool theory_seq::simplify_eq(expr* l, expr* r, enode_pair_dependency* deps) { } SASSERT(lhs.size() == rhs.size()); 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()); - m_dam.push_back(m_deps.back(), deps); + m_eqs.push_back(eq(expr_ref(lhs[i].get(), m), expr_ref(rhs[i].get(), m), deps)); } TRACE("seq", tout << mk_pp(l, m) << " = " << mk_pp(r, m) << " => "; - for (unsigned i = 0; i < lhs.size(); ++i) { - tout << mk_pp(lhs[i].get(), m) << " = " << mk_pp(rhs[i].get(), m) << "; "; + for (unsigned i = 0; i < m_eqs.size(); ++i) { + tout << m_eqs[i].m_lhs << " = " << m_eqs[i].m_rhs << "; "; } tout << "\n"; ); @@ -428,7 +493,6 @@ bool theory_seq::is_right_select(expr* a, expr*& b) { void theory_seq::add_solution(expr* l, expr* r, enode_pair_dependency* deps) { context& ctx = get_context(); m_rep.update(l, r, deps); - m_cache.reset(); // TBD: skip new equalities for non-internalized terms. if (ctx.e_internalized(l) && ctx.e_internalized(r)) { propagate_eq(deps, ctx.get_enode(l), ctx.get_enode(r)); @@ -446,23 +510,19 @@ bool theory_seq::solve_basic_eqs() { 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) { + for (unsigned i = 0; !ctx.inconsistent() && i < m_eqs.size(); ++i) { + eq e = m_eqs[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)); + simplify_eq(e.m_lhs, e.m_rhs, e.m_dep): + solve_unit_eq(e.m_lhs, e.m_rhs, e.m_dep)) { + if (i + 1 != m_eqs.size()) { + eq e1 = m_eqs[m_eqs.size()-1]; + m_eqs.set(i, e1); --i; ++m_stats.m_num_reductions; } - m.pop_back(lhs); - m.pop_back(rhs); - m_dam.pop_back(deps); + m_eqs.pop_back(); change = true; } } @@ -525,11 +585,6 @@ bool theory_seq::internalize_term(app* term) { !m_util.is_skolem(term)) { set_incomplete(term); } - expr* arg; - func_decl* fn; - if (m_util.str.is_length(term, arg) && !m_sort2len_fn.find(m.get_sort(arg), fn)) { - m_trail_stack.push(ast2ast_trail(m_sort2len_fn, m.get_sort(arg), term->get_decl())); - } return true; } @@ -538,14 +593,14 @@ void theory_seq::apply_sort_cnstr(enode* n, sort* s) { } void theory_seq::display(std::ostream & out) const { - if (m.size(m_lhs.back()) == 0 && + if (m_eqs.size() == 0 && m_ineqs.empty() && m_rep.empty() && m_exclude.empty()) { return; } out << "Theory seq\n"; - if (m.size(m_lhs.back()) > 0) { + if (m_eqs.size() > 0) { out << "Equations:\n"; display_equations(out); } @@ -566,22 +621,20 @@ void theory_seq::display(std::ostream & out) const { } void theory_seq::display_equations(std::ostream& out) const { - expr_array const& lhs = m_lhs.back(); - expr_array const& rhs = m_rhs.back(); - enode_pair_dependency_array const& deps = m_deps.back(); - for (unsigned i = 0; i < m.size(lhs); ++i) { - out << mk_pp(m.get(lhs, i), m) << " = " << mk_pp(m.get(rhs, i), m) << " <-\n"; - display_deps(out, m_dam.get(deps, i)); + for (unsigned i = 0; i < m_eqs.size(); ++i) { + eq const& e = m_eqs[i]; + out << e.m_lhs << " = " << e.m_rhs << " <- "; + display_deps(out, e.m_dep); } } void theory_seq::display_deps(std::ostream& out, enode_pair_dependency* dep) const { - if (!dep) return; vector _eqs; const_cast(m_dm).linearize(dep, _eqs); for (unsigned i = 0; i < _eqs.size(); ++i) { - out << " " << mk_pp(_eqs[i].first->get_owner(), m) << " = " << mk_pp(_eqs[i].second->get_owner(), m) << "\n"; + out << " " << mk_pp(_eqs[i].first->get_owner(), m) << " = " << mk_pp(_eqs[i].second->get_owner(), m); } + out << "\n"; } void theory_seq::collect_statistics(::statistics & st) const { @@ -642,36 +695,38 @@ expr_ref theory_seq::canonize(expr* e, enode_pair_dependency*& eqs) { expr_ref theory_seq::expand(expr* e, enode_pair_dependency*& eqs) { enode_pair_dependency* deps = 0; + expr_dep ed; expr* r = 0; - if (m_cache.find(e, r)) { - return expr_ref(r, m); + + if (m_rep.find_cache(e, ed)) { + eqs = m_dm.mk_join(eqs, ed.second); + return expr_ref(ed.first, m); } e = m_rep.find(e, deps); expr_ref result(m); expr* e1, *e2; - eqs = m_dm.mk_join(eqs, deps); if (m_util.str.is_concat(e, e1, e2)) { - result = m_util.str.mk_concat(expand(e1, eqs), expand(e2, eqs)); + result = m_util.str.mk_concat(expand(e1, deps), expand(e2, deps)); } else if (m_util.str.is_empty(e) || m_util.str.is_string(e)) { result = e; } else if (m.is_eq(e, e1, e2)) { - result = m.mk_eq(expand(e1, eqs), expand(e2, eqs)); + result = m.mk_eq(expand(e1, deps), expand(e2, deps)); } else if (m_util.str.is_prefix(e, e1, e2)) { - result = m_util.str.mk_prefix(expand(e1, eqs), expand(e2, eqs)); + result = m_util.str.mk_prefix(expand(e1, deps), expand(e2, deps)); } else if (m_util.str.is_suffix(e, e1, e2)) { - result = m_util.str.mk_suffix(expand(e1, eqs), expand(e2, eqs)); + result = m_util.str.mk_suffix(expand(e1, deps), expand(e2, deps)); } else if (m_util.str.is_contains(e, e1, e2)) { - result = m_util.str.mk_contains(expand(e1, eqs), expand(e2, eqs)); + result = m_util.str.mk_contains(expand(e1, deps), expand(e2, deps)); } else if (m_model_completion && is_var(e)) { SASSERT(m_factory); expr_ref val(m); - val = m_factory->get_fresh_value(m.get_sort(e)); + val = m_factory->get_some_value(m.get_sort(e)); if (val) { m_rep.update(e, val, 0); result = val; @@ -683,7 +738,8 @@ expr_ref theory_seq::expand(expr* e, enode_pair_dependency*& eqs) { else { result = e; } - m_cache.insert(e, result); + m_rep.add_cache(e, expr_dep(result, deps)); + eqs = m_dm.mk_join(eqs, deps); return result; } @@ -1072,13 +1128,10 @@ void theory_seq::new_eq_eh(theory_var v1, theory_var v2) { enode* n1 = get_enode(v1); enode* n2 = get_enode(v2); if (n1 != n2) { - expr* o1 = n1->get_owner(), *o2 = n2->get_owner(); - TRACE("seq", tout << mk_pp(o1, m) << " = " << mk_pp(o2, m) << "\n";); - m.push_back(m_lhs.back(), o1); - m.push_back(m_rhs.back(), o2); - m_dam.push_back(m_deps.back(), m_dm.mk_leaf(enode_pair(n1, n2))); - - // add length-equal axiom? + expr_ref o1(n1->get_owner(), m); + expr_ref o2(n2->get_owner(), m); + TRACE("seq", tout << o1 << " = " << o2 << "\n";); + m_eqs.push_back(eq(o1, o2, m_dm.mk_leaf(enode_pair(n1, n2)))); } } @@ -1091,54 +1144,27 @@ void theory_seq::new_diseq_eh(theory_var v1, theory_var v2) { } void theory_seq::push_scope_eh() { - TRACE("seq", tout << "push " << m_lhs.size() << "\n";); + TRACE("seq", tout << "push " << m_eqs.size() << "\n";); theory::push_scope_eh(); m_rep.push_scope(); m_exclude.push_scope(); m_dm.push_scope(); m_trail_stack.push_scope(); m_trail_stack.push(value_trail(m_axioms_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); + m_eqs.push_scope(); } void theory_seq::pop_scope_eh(unsigned num_scopes) { - TRACE("seq", tout << "pop " << m_lhs.size() << "\n";); + TRACE("seq", tout << "pop " << m_eqs.size() << "\n";); m_trail_stack.pop_scope(num_scopes); theory::pop_scope_eh(num_scopes); m_dm.pop_scope(num_scopes); m_rep.pop_scope(num_scopes); m_exclude.pop_scope(num_scopes); - 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(); - } - m_cache.reset(); + m_eqs.pop_scopes(num_scopes); } void theory_seq::restart_eh() { -#if 0 - m.del(m_lhs.back()); - m.del(m_rhs.back()); - m_dam.del(m_deps.back()); - m_lhs.reset(); - m_rhs.reset(); - m_deps.reset(); - m_lhs.push_back(expr_array()); - m_rhs.push_back(expr_array()); - m_deps.push_back(enode_pair_dependency_array()); -#endif } void theory_seq::relevant_eh(app* n) { diff --git a/src/smt/theory_seq.h b/src/smt/theory_seq.h index 1bf0454a8..ad500aac6 100644 --- a/src/smt/theory_seq.h +++ b/src/smt/theory_seq.h @@ -23,37 +23,38 @@ Revision History: #include "seq_decl_plugin.h" #include "theory_seq_empty.h" #include "th_rewriter.h" -#include "union_find.h" #include "ast_trail.h" +#include "scoped_vector.h" 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_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_manager; - static const bool ref_count = false; - }; - typedef parray_manager enode_pair_dependency_array_manager; - typedef enode_pair_dependency_array_manager::ref enode_pair_dependency_array; - typedef union_find th_union_find; typedef trail_stack th_trail_stack; + typedef std::pair expr_dep; + typedef obj_map eqdep_map_t; + + // cache to track evaluations under equalities + class eval_cache { + eqdep_map_t m_map; + expr_ref_vector m_trail; + public: + eval_cache(ast_manager& m): m_trail(m) {} + bool find(expr* v, expr_dep& r) const { return m_map.find(v, r); } + void insert(expr* v, expr_dep& r) { m_trail.push_back(v); m_trail.push_back(r.first); m_map.insert(v, r); } + void reset() { m_map.reset(); m_trail.reset(); } + }; + // map from variables to representatives + // + a cache for normalization. class solution_map { enum map_update { INS, DEL }; - typedef obj_map > map_t; ast_manager& m; enode_pair_dependency_manager& m_dm; - map_t m_map; + eqdep_map_t m_map; + eval_cache m_cache; expr_ref_vector m_lhs, m_rhs; ptr_vector m_deps; svector m_updates; @@ -61,15 +62,20 @@ namespace smt { void add_trail(map_update op, expr* l, expr* r, enode_pair_dependency* d); public: - solution_map(ast_manager& m, enode_pair_dependency_manager& dm): m(m), m_dm(dm), m_lhs(m), m_rhs(m) {} + solution_map(ast_manager& m, enode_pair_dependency_manager& dm): + m(m), m_cache(m), m_dm(dm), m_lhs(m), m_rhs(m) {} bool empty() const { return m_map.empty(); } void update(expr* e, expr* r, enode_pair_dependency* d); + void add_cache(expr* v, expr_dep& r) { m_cache.insert(v, r); } + bool find_cache(expr* v, expr_dep& r) { return m_cache.find(v, r); } expr* find(expr* e, enode_pair_dependency*& d); + void cache(expr* e, expr* r, enode_pair_dependency* d); void push_scope() { m_limit.push_back(m_updates.size()); } void pop_scope(unsigned num_scopes); void display(std::ostream& out) const; }; + // Table of current disequalities class exclusion_table { typedef obj_pair_hashtable table_t; ast_manager& m; @@ -87,14 +93,15 @@ namespace smt { void display(std::ostream& out) const; }; - class eval_cache { - obj_map m_map; - expr_ref_vector m_trail; - public: - eval_cache(ast_manager& m): m_trail(m) {} - bool find(expr* v, expr*& r) const { return m_map.find(v, r); } - void insert(expr* v, expr* r) { m_trail.push_back(v); m_trail.push_back(r); m_map.insert(v, r); } - void reset() { m_map.reset(); m_trail.reset(); } + // Asserted or derived equality with dependencies + struct eq { + expr_ref m_lhs; + expr_ref m_rhs; + enode_pair_dependency* m_dep; + eq(expr_ref& l, expr_ref& r, enode_pair_dependency* d): + m_lhs(l), m_rhs(r), m_dep(d) {} + eq(eq const& other): m_lhs(other.m_lhs), m_rhs(other.m_rhs), m_dep(other.m_dep) {} + eq& operator=(eq const& other) { m_lhs = other.m_lhs; m_rhs = other.m_rhs; m_dep = other.m_dep; return *this; } }; struct stats { @@ -104,16 +111,10 @@ namespace smt { unsigned m_num_reductions; }; 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; solution_map m_rep; // unification representative. - vector m_lhs, m_rhs; // persistent sets of equalities. - vector m_deps; // persistent sets of dependencies. - eval_cache m_cache; + scoped_vector m_eqs; // set of current equations. - ast2ast_trailmap m_sort2len_fn; // length functions per sort. seq_factory* m_factory; // value factory expr_ref_vector m_ineqs; // inequalities to check solution against exclusion_table m_exclude; // set of asserted disequalities. @@ -162,6 +163,9 @@ namespace smt { bool simplify_and_solve_eqs(); // solve unitary equalities bool branch_variable(); // branch on a variable bool split_variable(); // split a variable + bool is_solved(); + bool check_length_coherence(); + bool check_ineq_coherence(); bool pre_process_eqs(bool simplify_or_solve); bool simplify_eqs(); diff --git a/src/smt/theory_seq_empty.h b/src/smt/theory_seq_empty.h index 58a0fa85f..04f38020c 100644 --- a/src/smt/theory_seq_empty.h +++ b/src/smt/theory_seq_empty.h @@ -64,9 +64,14 @@ namespace smt { } virtual expr* get_some_value(sort* s) { - if (u.is_string(s)) - return u.str.mk_string(symbol("")); - NOT_IMPLEMENTED_YET(); + if (u.is_seq(s)) { + return u.str.mk_empty(s); + } + sort* seq = 0; + if (u.is_re(s, seq)) { + return u.re.mk_to_re(u.str.mk_empty(seq)); + } + UNREACHABLE(); return 0; } virtual bool get_some_values(sort* s, expr_ref& v1, expr_ref& v2) { diff --git a/src/util/scoped_vector.h b/src/util/scoped_vector.h new file mode 100644 index 000000000..ed75fd561 --- /dev/null +++ b/src/util/scoped_vector.h @@ -0,0 +1,128 @@ +/*++ +Copyright (c) 2015 Microsoft Corporation + +Module Name: + + scoped_vector.h + +Abstract: + + Vector that restores during backtracking. + +Author: + + Nikolaj Bjorner (nbjorner) 2015-12-13 + +Revision History: + +--*/ +#ifndef SCOPED_VECTOR_H_ +#define SCOPED_VECTOR_H_ + +#include"vector.h" + +template +class scoped_vector { + unsigned m_size; + unsigned m_elems_start; + unsigned_vector m_sizes; + vector m_elems; + unsigned_vector m_elems_lim; + unsigned_vector m_index; + unsigned_vector m_src, m_dst; + unsigned_vector m_src_lim; +public: + scoped_vector(): m_size(0), m_elems_start(0) {} + + // m_index : External-Index -> Internal-Index + // m_index.size() = max(m_sizes) + // m_src[i] -> m_dst[i] // trail into m_index updates + // m_src_lim last index to be updated. + + void push_scope() { + m_elems_start = m_elems.size(); + m_sizes.push_back(m_size); + m_src_lim.push_back(m_src.size()); + m_elems_lim.push_back(m_elems_start); + } + + void pop_scopes(unsigned num_scopes) { + if (num_scopes == 0) return; + unsigned new_size = m_sizes.size() - num_scopes; + unsigned src_lim = m_src_lim[new_size]; + + for (unsigned i = m_src.size(); i > src_lim; ) { + --i; + m_index[m_src[i]] = m_dst[i]; + } + m_src.shrink(src_lim); + m_dst.shrink(src_lim); + m_src_lim.shrink(new_size); + + m_elems.shrink(m_elems_lim[new_size]); + m_elems_lim.resize(new_size); + m_elems_start = m_elems.size(); + + m_size = m_sizes[new_size]; + m_sizes.shrink(new_size); + } + + T const& operator[](unsigned idx) const { + SASSERT(idx < m_size); + return m_elems[m_index[idx]]; + } + + void set(unsigned idx, T const& t) { + SASSERT(idx < m_size); + unsigned n = m_index[idx]; + if (n >= m_elems_start) { + m_elems[n] = t; + } + else { + set_index(idx, m_elems.size()); + m_elems.push_back(t); + } + SASSERT(invariant()); + } + + void push_back(T const& t) { + set_index(m_size, m_elems.size()); + m_elems.push_back(t); + ++m_size; + SASSERT(invariant()); + } + + void pop_back() { + SASSERT(m_size > 0); + if (m_size == m_elems.size() && m_size > m_elems_start) { + m_elems.pop_back(); + } + --m_size; + SASSERT(invariant()); + } + + unsigned size() const { return m_size; } + + bool empty() const { return m_size == 0; } + +private: + void set_index(unsigned src, unsigned dst) { + while (src >= m_index.size()) { + m_index.push_back(0); + } + SASSERT(src < m_index.size()); + if (src < m_elems_start) { + m_src.push_back(src); + m_dst.push_back(m_index[src]); + } + m_index[src] = dst; + } + + bool invariant() const { + return + m_size <= m_elems.size() && + m_elems_start <= m_elems.size(); + } +}; + +#endif