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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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117
src/smt/seq_eq_solver.cpp
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@ -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;
}