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fixes and more porting seq_eq_solver to self-contained module

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This commit is contained in:
Nikolaj Bjorner 2021-03-04 16:23:22 -08:00
parent 847724fb21
commit 38737db802
21 changed files with 354 additions and 230 deletions
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3
src/ast/rewriter/seq_axioms.h
View file

@ -111,6 +111,9 @@ namespace seq {
expr_ref mk_ge(expr* x, rational const& n) { return mk_ge_e(x, a.mk_int(n)); }
expr_ref mk_le(expr* x, rational const& n) { return mk_le_e(x, a.mk_int(n)); }
void rewrite(expr_ref& e) { m_rewrite(e); }
skolem& sk() { return m_sk; }
};
};

323
src/ast/rewriter/seq_eq_solver.cpp
View file

@ -8,7 +8,7 @@ Module Name:
Abstract:
Solver-agnostic equality solving routines for sequences
Author:
Nikolaj Bjorner (nbjorner) 2021-03-01
@ -35,9 +35,25 @@ namespace seq {
return true;
if (reduce_itos2(e, r))
return true;
if (reduce_itos3(e, r))
return true;
if (reduce_binary_eq(e, r))
return true;
if (reduce_nth_solved(e, r))
return true;
return false;
}
bool eq_solver::branch(unsigned priority, eqr const& e) {
switch (priority) {
case 0:
return branch_unit_variable(e);
case 1:
default:
break;
}
return false;
}
@ -64,15 +80,15 @@ namespace seq {
* --------------------------
* s = t or (s < 0 and t < 0)
*/
bool eq_solver::match_itos1(eqr const& e, expr*& a, expr*& b) {
return
e.ls.size() == 1 && e.rs.size() == 1 &&
return
e.ls.size() == 1 && e.rs.size() == 1 &&
seq.str.is_itos(e.ls[0], a) && seq.str.is_itos(e.rs[0], b);
}
bool eq_solver::reduce_itos1(eqr const& e, eq_ptr& r) {
expr* s = nullptr, *t = nullptr;
expr* s = nullptr, * t = nullptr;
if (!match_itos1(e, s, t))
return false;
expr_ref eq = mk_eq(s, t);
@ -86,7 +102,7 @@ namespace seq {
* -----------------
* s < 0
*/
bool eq_solver::match_itos2(eqr const& e, expr*& s) {
if (e.ls.size() == 1 && e.rs.empty() && seq.str.is_itos(e.ls[0], s))
return true;
@ -103,11 +119,78 @@ namespace seq {
return true;
}
/**
* itos(n) = ""
* ------------
* n <= -1
*
* itos(n) = [d1]+[d2]+...+[dk]
* ---------------------------------
* n = 10^{k-1}*d1 + ... + dk
*
* k > 1 => d1 > 0
*/
bool eq_solver::match_itos3(eqr const& e, expr*& n, expr_ref_vector const*& es) {
if (e.ls.size() == 1 && seq.str.is_itos(e.ls[0], n)) {
es = &e.rs;
return true;
}
if (e.rs.size() == 1 && seq.str.is_itos(e.rs[0], n)) {
es = &e.ls;
return true;
}
return false;
}
bool eq_solver::reduce_itos3(eqr const& e, eq_ptr& r) {
expr* n = nullptr;
expr_ref_vector const* _es = nullptr;
if (!match_itos3(e, n, _es))
return false;
expr_ref_vector const& es = *_es;
if (es.empty()) {
add_consequence(m_ax.mk_le(n, -1));
return true;
}
expr* u = nullptr;
for (expr* r : es) {
if (seq.str.is_unit(r, u)) {
expr_ref is_digit = m_ax.is_digit(u);
if (!m.is_true(ctx.expr2rep(is_digit)))
add_consequence(is_digit);
}
}
if (!all_units(es, 0, es.size()))
return false;
expr_ref num(m);
for (expr* r : es) {
VERIFY(seq.str.is_unit(r, u));
expr_ref digit = m_ax.sk().mk_digit2int(u);
if (!num)
num = digit;
else
num = a.mk_add(a.mk_mul(a.mk_int(10), num), digit);
}
expr_ref eq(m.mk_eq(n, num), m);
m_ax.rewrite(eq);
add_consequence(eq);
if (es.size() > 1) {
VERIFY(seq.str.is_unit(es[0], u));
expr_ref digit = m_ax.sk().mk_digit2int(u);
add_consequence(m_ax.mk_ge(digit, 1));
}
return true;
}
/**
* x = t, where x does not occur in t.
*/
bool eq_solver::reduce_unit(eqr const& e, eq_ptr& r) {
if (e.ls == e.rs)
if (e.ls == e.rs)
return true;
if (e.ls.size() == 1 && is_var(e.ls[0]) && !occurs(e.ls[0], e.rs)) {
expr_ref y(seq.str.mk_concat(e.rs, e.ls[0]->get_sort()), m);
@ -145,7 +228,7 @@ namespace seq {
set_conflict();
return true;
}
if (xs.empty())
if (xs.empty())
return true;
if (xs.size() != 1)
@ -155,29 +238,105 @@ namespace seq {
return false;
expr_ref eq(m.mk_eq(xs[0], ys[0]), m);
expr* veq = ctx.expr2rep(eq);
if (m.is_true(veq))
if (m.is_true(veq))
return false;
add_consequence(eq);
return m.is_false(veq);
}
/**
* x = nth(unit(x, 0)) ++ ... ++ nth(unit(x,i))
* ------------------------------------------------
* x -> nth(unit(x, 0)) ++ ... ++ nth(unit(x,i))
*/
bool eq_solver::reduce_nth_solved(eqr const& e, eq_ptr& r) {
expr_ref x(m), y(m);
if (match_nth_solved(e, x, y)) {
ctx.add_solution(x, y);
return true;
}
return false;
}
bool eq_solver::match_nth_solved(eqr const& e, expr_ref& x, expr_ref& y) {
if (match_nth_solved_aux(e.ls, e.rs, x, y))
return true;
if (match_nth_solved_aux(e.rs, e.ls, x, y))
return true;
return false;
}
bool eq_solver::match_nth_solved_aux(expr_ref_vector const& ls, expr_ref_vector const& rs, expr_ref& x, expr_ref& y) {
if (ls.size() != 1 || !is_var(ls[0]))
return false;
expr* n = nullptr, * u = nullptr;
unsigned j = 0, i = 0;
for (expr* r : rs) {
if (seq.str.is_unit(r, u) && seq.str.is_nth_i(u, n, i) && i == j && n == ls[0])
++j;
else
return false;
}
x = ls[0];
y = seq.str.mk_concat(rs, x->get_sort());
return true;
}
/**
* XV == abcdef, where V is an arbitrary string
* ---------------------------------------------
* |X| <= |abcdef|
*
* |X| = k => X = a_1...a_k
*/
bool eq_solver::branch_unit_variable(expr* X, expr_ref_vector const& units) {
SASSERT(is_var(X));
rational lenX;
ctx.get_length(X, lenX);
if (lenX > units.size()) {
add_consequence(m_ax.mk_le(seq.str.mk_length(X), units.size()));
return true;
}
expr_ref eq_length(m.mk_eq(a.mk_int(lenX), seq.str.mk_length(X)), m);
expr* val = ctx.expr2rep(eq_length);
if (!m.is_false(val)) {
expr_ref Y(seq.str.mk_concat(lenX.get_unsigned(), units.c_ptr(), X->get_sort()), m);
expr_ref eq = m_ax.sk().mk_eq(X, Y);
add_consequence(~eq_length, eq);
return true;
}
return false;
}
bool eq_solver::branch_unit_variable(eqr const& e) {
if (!e.ls.empty() && is_var(e.ls[0]) && all_units(e.rs, 0, e.rs.size()))
return branch_unit_variable(e.ls[0], e.rs);
if (!e.rs.empty() && is_var(e.rs[0]) && all_units(e.ls, 0, e.ls.size()))
return branch_unit_variable(e.rs[0], e.ls);
return false;
}
bool eq_solver::is_var(expr* a) const {
return
seq.is_seq(a) &&
!seq.str.is_concat(a) &&
!seq.str.is_empty(a) &&
!seq.str.is_empty(a) &&
!seq.str.is_string(a) &&
!seq.str.is_unit(a) &&
!seq.str.is_itos(a) &&
!seq.str.is_nth_i(a) &&
!seq.str.is_nth_i(a) &&
!m.is_ite(a);
}
bool eq_solver::occurs(expr* a, expr_ref_vector const& b) {
for (auto const& elem : b)
if (a == elem || m.is_ite(elem))
return true;
for (auto const& elem : b)
if (a == elem || m.is_ite(elem))
return true;
return false;
}
@ -185,7 +344,7 @@ namespace seq {
// true if a occurs under an interpreted function or under left/right selector.
SASSERT(is_var(a));
SASSERT(m_todo.empty());
expr* e1 = nullptr, *e2 = nullptr;
expr* e1 = nullptr, * e2 = nullptr;
m_todo.push_back(b);
while (!m_todo.empty()) {
b = m_todo.back();
@ -220,8 +379,8 @@ namespace seq {
unsigned eq_solver::count_units_l2r(expr_ref_vector const& es, unsigned offset) const {
unsigned i = offset, sz = es.size();
for (; i < sz && seq.str.is_unit(es[i]); ++i) ;
return i - offset;
for (; i < sz && seq.str.is_unit(es[i]); ++i);
return i - offset;
}
unsigned eq_solver::count_units_r2l(expr_ref_vector const& es, unsigned offset) const {
@ -231,15 +390,14 @@ namespace seq {
if (!seq.str.is_unit(es[i]))
break;
++count;
}
while (i-- > 0);
} while (i-- > 0);
return count;
}
unsigned eq_solver::count_non_units_l2r(expr_ref_vector const& es, unsigned offset) const {
unsigned i = offset, sz = es.size();
for (; i < sz && !seq.str.is_unit(es[i]); ++i) ;
return i - offset;
for (; i < sz && !seq.str.is_unit(es[i]); ++i);
return i - offset;
}
unsigned eq_solver::count_non_units_r2l(expr_ref_vector const& es, unsigned offset) const {
@ -249,8 +407,7 @@ namespace seq {
if (seq.str.is_unit(es[i]))
break;
++count;
}
while (i-- > 0);
} while (i-- > 0);
return count;
}
@ -259,9 +416,9 @@ namespace seq {
* where U is a variable or concatenation of variables
*/
bool eq_solver::match_ternary_eq_r(expr_ref_vector const& ls, expr_ref_vector const& rs,
expr_ref& x, expr_ref_vector& xs, expr_ref& y1, expr_ref_vector& ys, expr_ref& y2) {
if (ls.size() > 1 && rs.size() > 1 && is_var(rs[0]) && is_var(rs.back())) {
bool eq_solver::match_ternary_eq_r(expr_ref_vector const& ls, expr_ref_vector const& rs,
expr_ref& x, expr_ref_vector& xs, expr_ref& y1, expr_ref_vector& ys, expr_ref& y2) {
if (ls.size() > 1 && rs.size() > 1 && is_var(rs[0]) && is_var(rs.back())) {
unsigned num_ls_units = count_units_r2l(ls, ls.size() - 1);
if (num_ls_units == 0 || num_ls_units == ls.size())
return false;
@ -273,33 +430,33 @@ namespace seq {
unsigned num_rs_units = count_units_r2l(rs, rs.size() - 1 - num_rs_non_units);
if (num_rs_units == 0)
return false;
set_prefix(x, ls, ls.size() - num_ls_units);
set_suffix(xs, ls, num_ls_units);
set_prefix(x, ls, ls.size() - num_ls_units);
set_suffix(xs, ls, num_ls_units);
unsigned offset = rs.size() - num_rs_non_units - num_rs_units;
set_prefix(y1, rs, offset);
set_prefix(y1, rs, offset);
set_extract(ys, rs, offset, num_rs_units);
set_suffix(y2, rs, num_rs_non_units);
set_suffix(y2, rs, num_rs_non_units);
return true;
}
return false;
}
bool eq_solver::match_ternary_eq_rhs(expr_ref_vector const& ls, expr_ref_vector const& rs,
expr_ref& x, expr_ref_vector& xs, expr_ref& y1, expr_ref_vector& ys, expr_ref& y2) {
bool eq_solver::match_ternary_eq_rhs(expr_ref_vector const& ls, expr_ref_vector const& rs,
expr_ref& x, expr_ref_vector& xs, expr_ref& y1, expr_ref_vector& ys, expr_ref& y2) {
if (match_ternary_eq_r(ls, rs, x, xs, y1, ys, y2))
return true;
if (match_ternary_eq_r(rs, ls, x, xs, y1, ys, y2))
return true;
return false;
}
/*
match: abc X .. = Y def Z ..
where Y is a variable or concatenation of variables
*/
bool eq_solver::match_ternary_eq_l(expr_ref_vector const& ls, expr_ref_vector const& rs,
expr_ref_vector& xs, expr_ref& x, expr_ref& y1, expr_ref_vector& ys, expr_ref& y2) {
bool eq_solver::match_ternary_eq_l(expr_ref_vector const& ls, expr_ref_vector const& rs,
expr_ref_vector& xs, expr_ref& x, expr_ref& y1, expr_ref_vector& ys, expr_ref& y2) {
if (ls.size() > 1 && rs.size() > 1 && is_var(rs[0]) && is_var(rs.back())) {
unsigned num_ls_units = count_units_l2r(ls, 0);
if (num_ls_units == 0 || num_ls_units == ls.size())
@ -310,18 +467,18 @@ namespace seq {
unsigned num_rs_units = count_units_l2r(rs, num_rs_non_units);
if (num_rs_units == 0)
return false;
set_prefix(xs, ls, num_ls_units);
set_suffix(x, ls, ls.size() - num_ls_units);
set_prefix(y1, rs, num_rs_non_units);
set_prefix(xs, ls, num_ls_units);
set_suffix(x, ls, ls.size() - num_ls_units);
set_prefix(y1, rs, num_rs_non_units);
set_extract(ys, rs, num_rs_non_units, num_rs_units);
set_suffix(y2, rs, rs.size() - num_rs_non_units - num_rs_units);
set_suffix(y2, rs, rs.size() - num_rs_non_units - num_rs_units);
return true;
}
return false;
}
bool eq_solver::match_ternary_eq_lhs(expr_ref_vector const& ls, expr_ref_vector const& rs,
expr_ref_vector& xs, expr_ref& x, expr_ref& y1, expr_ref_vector& ys, expr_ref& y2) {
bool eq_solver::match_ternary_eq_lhs(expr_ref_vector const& ls, expr_ref_vector const& rs,
expr_ref_vector& xs, expr_ref& x, expr_ref& y1, expr_ref_vector& ys, expr_ref& y2) {
if (match_ternary_eq_l(ls, rs, xs, x, y1, ys, y2))
return true;
if (match_ternary_eq_l(rs, ls, xs, x, y1, ys, y2))
@ -331,8 +488,8 @@ namespace seq {
bool eq_solver::all_units(expr_ref_vector const& es, unsigned start, unsigned end) const {
for (unsigned i = start; i < end; ++i)
if (!seq.str.is_unit(es[i]))
for (unsigned i = start; i < end; ++i)
if (!seq.str.is_unit(es[i]))
return false;
return true;
}
@ -340,9 +497,9 @@ namespace seq {
/**
match X abc = defg Y, for abc, defg non-empty
*/
bool eq_solver::match_binary_eq(expr_ref_vector const& ls, expr_ref_vector const& rs,
expr_ref& x, ptr_vector<expr>& xs, ptr_vector<expr>& ys, expr_ref& y) {
bool eq_solver::match_binary_eq(expr_ref_vector const& ls, expr_ref_vector const& rs,
expr_ref& x, ptr_vector<expr>& xs, ptr_vector<expr>& ys, expr_ref& y) {
if (ls.size() > 1 && is_var(ls[0]) &&
rs.size() > 1 && is_var(rs.back()) &&
all_units(ls, 1, ls.size()) &&
@ -369,8 +526,8 @@ namespace seq {
*/
bool eq_solver::match_quat_eq(expr_ref_vector const& ls, expr_ref_vector const& rs,
expr_ref& x1, expr_ref_vector& xs, expr_ref& x2,
expr_ref& y1, expr_ref_vector& ys, expr_ref& y2) {
expr_ref& x1, expr_ref_vector& xs, expr_ref& x2,
expr_ref& y1, expr_ref_vector& ys, expr_ref& y2) {
if (ls.size() > 1 && is_var(ls[0]) && is_var(ls.back()) &&
rs.size() > 1 && is_var(rs[0]) && is_var(rs.back())) {
unsigned ls_non_unit = count_non_units_l2r(ls, 0);
@ -385,18 +542,78 @@ namespace seq {
return false;
if (rs_unit == 0)
return false;
set_prefix(x1, ls, ls_non_unit);
set_prefix(x1, ls, ls_non_unit);
set_extract(xs, ls, ls_non_unit, ls_unit);
set_suffix(x2, ls, ls.size() - ls_non_unit - ls_unit);
set_prefix(y1, rs, rs_non_unit);
set_suffix(x2, ls, ls.size() - ls_non_unit - ls_unit);
set_prefix(y1, rs, rs_non_unit);
set_extract(ys, rs, rs_non_unit, rs_unit);
set_suffix(y2, rs, rs.size() - rs_non_unit - rs_unit);
set_suffix(y2, rs, rs.size() - rs_non_unit - rs_unit);
return true;
}
return false;
}
// exists x, y, rs' != empty s.t. (ls = x ++ rs ++ y) || (ls = rs' ++ y && rs = x ++ rs')
bool eq_solver::can_align_from_lhs_aux(expr_ref_vector const& ls, expr_ref_vector const& rs) {
SASSERT(!ls.empty() && !rs.empty());
for (unsigned i = 0; i < ls.size(); ++i) {
if (m.are_distinct(ls[i], rs.back()))
continue;
if (i == 0)
return true;
// ls = rs' ++ y && rs = x ++ rs', diff = |x|
bool same = true;
if (rs.size() > i) {
unsigned diff = rs.size() - (i + 1);
for (unsigned j = 0; same && j < i; ++j)
same = !m.are_distinct(ls[j], rs[diff + j]);
}
// ls = x ++ rs ++ y, diff = |x|
else {
unsigned diff = (i + 1) - rs.size();
for (unsigned j = 0; same && j + 1 < rs.size(); ++j)
same = !m.are_distinct(ls[diff + j], rs[j]);
}
if (same)
return true;
}
return false;
}
// exists x, y, rs' != empty s.t. (ls = x ++ rs ++ y) || (ls = x ++ rs' && rs = rs' ++ y)
bool eq_solver::can_align_from_rhs_aux(expr_ref_vector const& ls, expr_ref_vector const& rs) {
SASSERT(!ls.empty() && !rs.empty());
for (unsigned i = 0; i < ls.size(); ++i) {
unsigned diff = ls.size() - 1 - i;
if (m.are_distinct(ls[diff], rs[0]))
continue;
if (i == 0)
return true;
bool same = true;
// ls = x ++ rs' && rs = rs' ++ y, diff = |x|
if (rs.size() > i) {
for (unsigned j = 1; same && j <= i; ++j)
same = !m.are_distinct(ls[diff + j], rs[j]);
}
// ls = x ++ rs ++ y, diff = |x|
else {
for (unsigned j = 1; same && j < rs.size(); ++j)
same = !m.are_distinct(ls[diff + j], rs[j]);
}
if (same)
return true;
}
return false;
}
};

19
src/ast/rewriter/seq_eq_solver.h
View file

@ -16,6 +16,7 @@ Author:
--*/
#pragma once
#include "ast/arith_decl_plugin.h"
#include "ast/rewriter/seq_axioms.h"
namespace seq {
@ -48,6 +49,7 @@ namespace seq {
ast_manager& m;
eq_solver_context& ctx;
axioms& m_ax;
arith_util a;
seq_util seq;
expr_ref_vector m_clause;
@ -59,9 +61,16 @@ namespace seq {
bool match_itos2(eqr const& e, expr*& s);
bool reduce_itos2(eqr const& e, eq_ptr& r);
bool reduce_itos3(eqr const& e, eq_ptr& r);
bool match_itos3(eqr const& e, expr*& n, expr_ref_vector const* & es);
bool match_binary_eq(eqr const& e, expr_ref& x, ptr_vector<expr>& xs, ptr_vector<expr>& ys, expr_ref& y);
bool reduce_binary_eq(eqr const& e, eq_ptr& r);
bool reduce_nth_solved(eqr const& e, eq_ptr& r);
bool match_nth_solved(eqr const& e, expr_ref& x, expr_ref& y);
bool match_nth_solved_aux(expr_ref_vector const& ls, expr_ref_vector const& rs, expr_ref& x, expr_ref& y);
bool match_ternary_eq_r(expr_ref_vector const& ls, expr_ref_vector const& rs,
expr_ref& x, expr_ref_vector& xs, expr_ref& y1, expr_ref_vector& ys, expr_ref& y2);
@ -69,6 +78,10 @@ namespace seq {
expr_ref_vector& xs, expr_ref& x, expr_ref& y1, expr_ref_vector& ys, expr_ref& y2);
bool branch_unit_variable(eqr const& e);
bool branch_unit_variable(expr* X, expr_ref_vector const& units);
/**
* count unit or non-unit entries left-to-right or right-to-left starting at, and including offset.
*/
@ -115,6 +128,7 @@ namespace seq {
m(m),
ctx(ctx),
m_ax(ax),
a(m),
seq(m),
m_clause(m)
{}
@ -123,6 +137,8 @@ namespace seq {
bool reduce(expr* s, expr* t, eq_ptr& r);
bool branch(unsigned priority, eqr const& e);
bool is_var(expr* a) const;
bool match_binary_eq(expr_ref_vector const& ls, expr_ref_vector const& rs,
@ -137,6 +153,9 @@ namespace seq {
bool match_quat_eq(expr_ref_vector const& ls, expr_ref_vector const& rs,
expr_ref& x1, expr_ref_vector& xs, expr_ref& x2,
expr_ref& y1, expr_ref_vector& ys, expr_ref& y2);
bool can_align_from_lhs_aux(expr_ref_vector const& ls, expr_ref_vector const& rs);
bool can_align_from_rhs_aux(expr_ref_vector const& ls, expr_ref_vector const& rs);
};

4
src/model/model.cpp
View file

@ -125,6 +125,10 @@ expr * model::get_fresh_value(sort * s) {
return get_factory(s)->get_fresh_value(s);
}
void model::register_value(expr* e) {
get_factory(e->get_sort())->register_value(e);
}
bool model::get_some_values(sort * s, expr_ref& v1, expr_ref& v2) {
return get_factory(s)->get_some_values(s, v1, v2);
}

1
src/model/model.h
View file

@ -70,6 +70,7 @@ public:
expr * get_some_value(sort * s) override;
expr * get_fresh_value(sort * s) override;
void register_value(expr* n);
bool get_some_values(sort * s, expr_ref & v1, expr_ref & v2) override;
ptr_vector<expr> const & get_universe(sort * s) const override;

2
src/sat/sat_solver.cpp
View file

@ -1029,7 +1029,7 @@ namespace sat {
return false;
} while (m_qhead < m_trail.size());
if (m_ext)
if (m_ext && !is_probing())
m_ext->unit_propagate();
}
if (m_inconsistent)

9
src/sat/smt/arith_solver.cpp
View file

@ -626,12 +626,16 @@ namespace arith {
ctx.get_rewriter()(value);
}
else {
UNREACHABLE();
value = mdl.get_fresh_value(o->get_sort());
}
mdl.register_value(value);
values.set(n->get_root_id(), value);
}
void solver::add_dep(euf::enode* n, top_sort<euf::enode>& dep) {
bool solver::add_dep(euf::enode* n, top_sort<euf::enode>& dep) {
theory_var v = n->get_th_var(get_id());
if (v == euf::null_theory_var && !a.is_arith_expr(n->get_expr()))
return false;
expr* e = n->get_expr();
if (a.is_arith_expr(e) && to_app(e)->get_num_args() > 0) {
for (auto* arg : euf::enode_args(n))
@ -640,6 +644,7 @@ namespace arith {
else {
dep.insert(n, nullptr);
}
return true;
}
void solver::push_core() {

2
src/sat/smt/arith_solver.h
View file

@ -429,7 +429,7 @@ namespace arith {
void init_model() override;
void finalize_model(model& mdl) override { DEBUG_CODE(dbg_finalize_model(mdl);); }
void add_value(euf::enode* n, model& mdl, expr_ref_vector& values) override;
void add_dep(euf::enode* n, top_sort<euf::enode>& dep) override;
bool add_dep(euf::enode* n, top_sort<euf::enode>& dep) override;
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;

5
src/sat/smt/array_model.cpp
View file

@ -22,10 +22,10 @@ Author:
namespace array {
void solver::add_dep(euf::enode* n, top_sort<euf::enode>& dep) {
bool solver::add_dep(euf::enode* n, top_sort<euf::enode>& dep) {
if (!a.is_array(n->get_expr())) {
dep.insert(n, nullptr);
return;
return true;
}
for (euf::enode* p : euf::enode_parents(n)) {
if (a.is_default(p->get_expr())) {
@ -41,6 +41,7 @@ namespace array {
for (euf::enode* k : euf::enode_class(n))
if (a.is_const(k->get_expr()))
dep.add(n, k->get_arg(0));
return true;
}

2
src/sat/smt/array_solver.h
View file

@ -207,7 +207,7 @@ namespace array {
void new_diseq_eh(euf::th_eq const& eq) override;
bool unit_propagate() override;
void add_value(euf::enode* n, model& mdl, expr_ref_vector& values) override;
void add_dep(euf::enode* n, top_sort<euf::enode>& dep) override;
bool add_dep(euf::enode* n, top_sort<euf::enode>& dep) override;
sat::literal internalize(expr* e, bool sign, bool root, bool learned) override;
void internalize(expr* e, bool redundant) override;
euf::theory_var mk_var(euf::enode* n) override;

5
src/sat/smt/dt_solver.cpp
View file

@ -703,15 +703,16 @@ namespace dt {
values.set(n->get_root_id(), m.mk_app(c_decl, m_args));
}
void solver::add_dep(euf::enode* n, top_sort<euf::enode>& dep) {
bool solver::add_dep(euf::enode* n, top_sort<euf::enode>& dep) {
theory_var v = n->get_th_var(get_id());
if (!is_datatype(n->get_expr()))
return;
return true;
euf::enode* con = m_var_data[m_find.find(v)]->m_constructor;
if (con->num_args() == 0)
dep.insert(n, nullptr);
for (enode* arg : euf::enode_args(con))
dep.add(n, arg->get_root());
return true;
}
sat::literal solver::internalize(expr* e, bool sign, bool root, bool redundant) {

2
src/sat/smt/dt_solver.h
View file

@ -149,7 +149,7 @@ namespace dt {
void new_eq_eh(euf::th_eq const& eq) override;
bool unit_propagate() override { return false; }
void add_value(euf::enode* n, model& mdl, expr_ref_vector& values) override;
void add_dep(euf::enode* n, top_sort<euf::enode>& dep) override;
bool add_dep(euf::enode* n, top_sort<euf::enode>& dep) override;
sat::literal internalize(expr* e, bool sign, bool root, bool redundant) override;
void internalize(expr* e, bool redundant) override;
euf::theory_var mk_var(euf::enode* n) override;

19
src/sat/smt/euf_model.cpp
View file

@ -88,18 +88,31 @@ namespace euf {
}
void solver::collect_dependencies(user_sort& us, deps_t& deps) {
ptr_buffer<enode> fresh_values;
for (enode* n : m_egraph.nodes()) {
expr* e = n->get_expr();
sort* srt = e->get_sort();
auto* mb = sort2solver(srt);
if (mb)
mb->add_dep(n, deps);
else
if (!mb)
deps.insert(n, nullptr);
else if (!mb->add_dep(n, deps))
fresh_values.push_back(n);
if (n->is_root() && m.is_uninterp(srt) && m.is_value(e))
us.register_value(e);
}
// fresh values depend on all non-fresh values of the same sort
for (enode* n : fresh_values) {
n->mark1();
deps.insert(n, nullptr);
}
for (enode* n : fresh_values)
for (enode* r : m_egraph.nodes())
if (r->is_root() && r->get_sort() == n->get_sort() && !r->is_marked1())
deps.add(n, r);
for (enode* n : fresh_values)
n->unmark1();
TRACE("euf",
for (auto const& d : deps.deps())
if (d.m_value) {

7
src/sat/smt/fpa_solver.cpp
View file

@ -318,22 +318,27 @@ namespace fpa {
values.set(n->get_root_id(), value);
}
void solver::add_dep(euf::enode* n, top_sort<euf::enode>& dep) {
bool solver::add_dep(euf::enode* n, top_sort<euf::enode>& dep) {
expr* e = n->get_expr();
if (m_fpa_util.is_fp(e)) {
SASSERT(n->num_args() == 3);
for (enode* arg : euf::enode_args(n))
dep.add(n, arg);
return true;
}
else if (m_fpa_util.is_bv2rm(e)) {
SASSERT(n->num_args() == 1);
dep.add(n, n->get_arg(0));
return true;
}
else if (m_fpa_util.is_rm(e) || m_fpa_util.is_float(e)) {
euf::enode* wrapped = expr2enode(m_converter.wrap(e));
if (wrapped)
dep.add(n, wrapped);
return nullptr != wrapped;
}
else
return false;
}
std::ostream& solver::display(std::ostream& out) const {

2
src/sat/smt/fpa_solver.h
View file

@ -64,7 +64,7 @@ namespace fpa {
std::ostream& display_justification(std::ostream& out, sat::ext_justification_idx idx) const override { UNREACHABLE(); return out; }
std::ostream& display_constraint(std::ostream& out, sat::ext_constraint_idx idx) const override { UNREACHABLE(); return out; }
void add_value(euf::enode* n, model& mdl, expr_ref_vector& values) override;
void add_dep(euf::enode* n, top_sort<euf::enode>& dep) override;
bool add_dep(euf::enode* n, top_sort<euf::enode>& dep) override;
void finalize_model(model& mdl) override;
bool unit_propagate() override { return false; }

2
src/sat/smt/sat_th.h
View file

@ -79,7 +79,7 @@ namespace euf {
/**
\brief compute dependencies for node n
*/
virtual void add_dep(euf::enode* n, top_sort<euf::enode>& dep) { dep.insert(n, nullptr); }
virtual bool add_dep(euf::enode* n, top_sort<euf::enode>& dep) { dep.insert(n, nullptr); return true; }
/**
\brief should function be included in model.

117
src/smt/seq_eq_solver.cpp
View file

@ -75,13 +75,10 @@ bool theory_seq::solve_eq(unsigned idx) {
}
TRACE("seq_verbose", tout << ls << " = " << rs << "\n";);
if (!ctx.inconsistent() && solve_nth_eq1(ls, rs, deps)) {
if (!ctx.inconsistent() && solve_nth_eq(ls, rs, deps)) {
return true;
}
if (!ctx.inconsistent() && solve_nth_eq1(rs, ls, deps)) {
return true;
}
if (!ctx.inconsistent() && solve_itos(rs, ls, deps)) {
if (!ctx.inconsistent() && solve_nth_eq(rs, ls, deps)) {
return true;
}
if (!ctx.inconsistent() && change) {
@ -674,42 +671,11 @@ bool theory_seq::can_align_from_lhs(expr_ref_vector const& ls, expr_ref_vector c
expr_ref r = mk_concat(rs);
expr_ref pair(m.mk_eq(l,r), m);
bool result;
if (m_overlap_lhs.find(pair, result)) {
return result;
if (!m_overlap_lhs.find(pair, result)) {
result = m_eq.can_align_from_lhs_aux(ls, rs);
m_overlap_lhs.insert(pair, result);
}
for (unsigned i = 0; i < ls.size(); ++i) {
if (!m.are_distinct(ls[i], rs.back())) {
bool same = true;
if (i == 0) {
m_overlap_lhs.insert(pair, true);
return true;
}
// ls = rs' ++ y && rs = x ++ rs', diff = |x|
if (rs.size() > i) {
unsigned diff = rs.size() - (i + 1);
for (unsigned j = 0; same && j < i; ++j) {
same = !m.are_distinct(ls[j], rs[diff + j]);
}
if (same) {
m_overlap_lhs.insert(pair, true);
return true;
}
}
// ls = x ++ rs ++ y, diff = |x|
else {
unsigned diff = (i + 1) - rs.size();
for (unsigned j = 0; same && j + 1 < rs.size(); ++j) {
same = !m.are_distinct(ls[diff + j], rs[j]);
}
if (same) {
m_overlap_lhs.insert(pair, true);
return true;
}
}
}
}
m_overlap_lhs.insert(pair, false);
return false;
return result;
}
// exists x, y, rs' != empty s.t. (ls = x ++ rs ++ y) || (ls = x ++ rs' && rs = rs' ++ y)
@ -717,45 +683,16 @@ bool theory_seq::can_align_from_rhs(expr_ref_vector const& ls, expr_ref_vector c
SASSERT(!ls.empty() && !rs.empty());
expr_ref l = mk_concat(ls);
expr_ref r = mk_concat(rs);
expr_ref pair(m.mk_eq(l,r), m);
expr_ref pair(m.mk_eq(l, r), m);
bool result;
if (m_overlap_rhs.find(pair, result)) {
return result;
if (!m_overlap_rhs.find(pair, result)) {
result = m_eq.can_align_from_rhs_aux(ls, rs);
m_overlap_rhs.insert(pair, result);
}
for (unsigned i = 0; i < ls.size(); ++i) {
unsigned diff = ls.size()-1-i;
if (!m.are_distinct(ls[diff], rs[0])) {
bool same = true;
if (i == 0) {
m_overlap_rhs.insert(pair, true);
return true;
}
// ls = x ++ rs' && rs = rs' ++ y, diff = |x|
if (rs.size() > i) {
for (unsigned j = 1; same && j <= i; ++j) {
same = !m.are_distinct(ls[diff+j], rs[j]);
}
if (same) {
m_overlap_rhs.insert(pair, true);
return true;
}
}
// ls = x ++ rs ++ y, diff = |x|
else {
for (unsigned j = 1; same && j < rs.size(); ++j) {
same = !m.are_distinct(ls[diff + j], rs[j]);
}
if (same) {
m_overlap_rhs.insert(pair, true);
return true;
}
}
}
}
m_overlap_rhs.insert(pair, false);
return false;
return result;
}
// Equation is of the form x ++ xs = y1 ++ ys ++ y2 where xs, ys are units.
// If xs and ys cannot align then
// x ++ xs = y1 ++ ys ++ y2 => x = y1 ++ ys ++ z, z ++ xs = y2
@ -1365,7 +1302,7 @@ struct remove_obj_pair_map : public trail {
x = pre(x, idx) ++ unit(rhs) ++ post(x, idx + 1)
NB: need 0 <= idx < len(rhs)
*/
bool theory_seq::solve_nth_eq2(expr_ref_vector const& ls, expr_ref_vector const& rs, dependency* deps) {
bool theory_seq::solve_nth_eq(expr_ref_vector const& ls, expr_ref_vector const& rs, dependency* deps) {
expr* s = nullptr, *idx = nullptr;
if (ls.size() == 1 && m_util.str.is_nth_i(ls[0], s, idx)) {
rational r;
@ -1389,32 +1326,4 @@ bool theory_seq::solve_nth_eq2(expr_ref_vector const& ls, expr_ref_vector const&
return false;
}
/**
match
x = unit(nth_i(x,0)) + unit(nth_i(x,1)) + .. + unit(nth_i(x,k-1))
*/
bool theory_seq::solve_nth_eq1(expr_ref_vector const& ls, expr_ref_vector const& rs, dependency* dep) {
if (solve_nth_eq2(ls, rs, dep)) {
return true;
}
if (ls.size() != 1 || rs.size() <= 1) {
return false;
}
expr* l = ls.get(0);
rational val;
if (!get_length(l, val) || val != rational(rs.size())) {
return false;
}
for (unsigned i = 0; i < rs.size(); ++i) {
unsigned k = 0;
expr* ru = nullptr, *r = nullptr;
if (m_util.str.is_unit(rs.get(i), ru) && m_util.str.is_nth_i(ru, r, k) && k == i && r == l) {
continue;
}
return false;
}
add_solution(l, mk_concat(rs, l->get_sort()), dep);
return true;
}

2
src/smt/smt_model_generator.cpp
View file

@ -116,7 +116,7 @@ namespace smt {
SASSERT(proc);
}
else {
TRACE("model", tout << "creating fresh value for #" << r->get_owner_id() << "\n";);
TRACE("model", tout << "creating fresh value for #" << mk_pp(r->get_expr(), m) << "\n";);
proc = alloc(fresh_value_proc, mk_extra_fresh_value(r->get_sort()));
}
}

51
src/smt/theory_seq.cpp
View file

@ -931,57 +931,6 @@ bool theory_seq::simplify_eq(expr_ref_vector& ls, expr_ref_vector& rs, dependenc
return true;
}
bool theory_seq::solve_itos(expr_ref_vector const& ls, expr_ref_vector const& rs, dependency* dep) {
expr* e = nullptr;
if (rs.size() == 1 && m_util.str.is_itos(rs[0], e) && solve_itos(e, ls, dep))
return true;
if (ls.size() == 1 && m_util.str.is_itos(ls[0], e) && solve_itos(e, rs, dep))
return true;
return false;
}
bool theory_seq::solve_itos(expr* n, expr_ref_vector const& rs, dependency* dep) {
if (rs.empty()) {
literal lit = m_ax.mk_le(n, -1);
propagate_lit(dep, 0, nullptr, lit);
return true;
}
expr* u = nullptr;
for (expr* r : rs) {
if (m_util.str.is_unit(r, u) && !m_is_digit.contains(u)) {
m_is_digit.insert(u);
m_trail_stack.push(insert_obj_trail<expr>(m_is_digit, u));
literal is_digit = m_ax.is_digit(u);
if (ctx.get_assignment(is_digit) != l_true) {
propagate_lit(dep, 0, nullptr, is_digit);
}
}
}
expr_ref num(m), digit(m);
for (expr* r : rs) {
if (!m_util.str.is_unit(r, u))
return false;
digit = m_sk.mk_digit2int(u);
if (!num) {
num = digit;
}
else {
num = m_autil.mk_add(m_autil.mk_mul(m_autil.mk_int(10), num), digit);
}
}
propagate_lit(dep, 0, nullptr, mk_simplified_literal(m.mk_eq(n, num)));
if (rs.size() > 1) {
VERIFY (m_util.str.is_unit(rs[0], u));
digit = m_sk.mk_digit2int(u);
propagate_lit(dep, 0, nullptr, m_ax.mk_ge(digit, 1));
}
return true;
}
bool theory_seq::reduce_length(expr* l, expr* r, literal_vector& lits) {
expr_ref len1(m), len2(m);

5
src/smt/theory_seq.h
View file

@ -464,11 +464,8 @@ namespace smt {
bool solve_eq(unsigned idx);
bool simplify_eq(expr_ref_vector& l, expr_ref_vector& r, dependency* dep);
bool lift_ite(expr_ref_vector const& l, expr_ref_vector const& r, dependency* dep);
bool solve_nth_eq1(expr_ref_vector const& ls, expr_ref_vector const& rs, dependency* dep);
obj_pair_hashtable<expr, expr> m_nth_eq2_cache;
bool solve_nth_eq2(expr_ref_vector const& ls, expr_ref_vector const& rs, dependency* dep);
bool solve_itos(expr_ref_vector const& ls, expr_ref_vector const& rs, dependency* dep);
bool solve_itos(expr* n, expr_ref_vector const& rs, dependency* dep);
bool solve_nth_eq(expr_ref_vector const& ls, expr_ref_vector const& rs, dependency* dep);
bool solve_binary_eq(expr_ref_vector const& l, expr_ref_vector const& r, dependency* dep);
bool propagate_max_length(expr* l, expr* r, dependency* dep);

2
src/util/top_sort.h
View file

@ -97,7 +97,7 @@ public:
void add(T* t, T* s) {
T_set* tb = nullptr;
if (!m_deps.find(t, tb)) {
if (!m_deps.find(t, tb) || !tb) {
tb = alloc(T_set);
insert(t, tb);
}