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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 21:03:28 -08:00
parent 24de0a9b90
commit 94bd2fdbe4
7 changed files with 285 additions and 78 deletions
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49
src/ast/rewriter/seq_rewriter.cpp
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@ -636,7 +636,12 @@ bool seq_rewriter::reduce_eq(expr* l, expr* r, expr_ref_vector& lhs, expr_ref_ve
}
change = true;
}
bool is_sat;
if (!change) {
if (is_subsequence(m_lhs.size(), m_lhs.c_ptr(), m_rhs.size(), m_rhs.c_ptr(), lhs, rhs, is_sat)) {
return is_sat;
}
lhs.push_back(l);
rhs.push_back(r);
}
@ -649,7 +654,13 @@ bool seq_rewriter::reduce_eq(expr* l, expr* r, expr_ref_vector& lhs, expr_ref_ve
else if (head2 == m_rhs.size()) {
return set_empty(m_lhs.size() - head1, m_lhs.c_ptr() + head1, lhs, rhs);
}
else { // head1 < m_lhs.size() && head2 < m_rhs.size() // could solve if either side is fixed size.
else { // could solve if either side is fixed size.
SASSERT(head1 < m_lhs.size() && head2 < m_rhs.size());
if (is_subsequence(m_lhs.size() - head1, m_lhs.c_ptr() + head1,
m_rhs.size() - head2, m_rhs.c_ptr() + head2, lhs, rhs, is_sat)) {
return is_sat;
}
lhs.push_back(m_util.str.mk_concat(m_lhs.size() - head1, m_lhs.c_ptr() + head1));
rhs.push_back(m_util.str.mk_concat(m_rhs.size() - head2, m_rhs.c_ptr() + head2));
}
@ -674,3 +685,39 @@ bool seq_rewriter::set_empty(unsigned sz, expr* const* es, expr_ref_vector& lhs,
}
return true;
}
bool seq_rewriter::is_subsequence(unsigned szl, expr* const* l, unsigned szr, expr* const* r,
expr_ref_vector& lhs, expr_ref_vector& rhs, bool& is_sat) {
is_sat = true;
if (szl == szr) return false;
if (szr < szl) {
std::swap(szl, szr);
std::swap(l, r);
}
for (unsigned i = 1; i + szl <= szr; ++i) {
bool eq = true;
for (unsigned j = 0; eq && j < szl; ++j) {
eq = l[j] == r[i+j];
}
if (eq) {
SASSERT(szr >= i + szl);
is_sat = set_empty(i, r, lhs, rhs);
is_sat &= set_empty(szr - (i + szl), r + i + szl, lhs, rhs);
TRACE("seq",
for (unsigned k = 0; k < szl; ++k) {
tout << mk_pp(l[k], m()) << " ";
}
tout << "\n";
for (unsigned k = 0; k < szr; ++k) {
tout << mk_pp(r[k], m()) << " ";
}
tout << "\n";
tout << lhs << "; " << rhs << "\n";);
return true;
}
}
return false;
}