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This commit is contained in:
Nikolaj Bjorner 2021-03-06 12:36:14 -08:00
parent 8de96009cd
commit 7edc99f807

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@ -126,6 +126,8 @@ expr* theory_seq::expr2rep(expr* e) {
}
#if 0
/**
\brief
@ -158,7 +160,6 @@ expr* theory_seq::expr2rep(expr* e) {
TODO: propagate length offsets for last vars
*/
#if 0
bool theory_seq::find_better_rep(expr_ref_vector const& ls, expr_ref_vector const& rs, unsigned idx,
dependency*& deps, expr_ref_vector & res) {
@ -235,6 +236,32 @@ bool theory_seq::find_better_rep(expr_ref_vector const& ls, expr_ref_vector cons
}
return false;
}
int theory_seq::find_fst_non_empty_idx(expr_ref_vector const& xs) {
for (unsigned i = 0; i < xs.size(); ++i) {
expr* x = xs[i];
if (!is_var(x))
return -1;
expr_ref e = mk_len(x);
if (ctx.e_internalized(e)) {
enode* root = ctx.get_enode(e)->get_root();
rational val;
if (m_autil.is_numeral(root->get_expr(), val) && val.is_zero()) {
continue;
}
}
return i;
}
return -1;
}
expr* theory_seq::find_fst_non_empty_var(expr_ref_vector const& x) {
int i = find_fst_non_empty_idx(x);
if (i >= 0)
return x[i];
return nullptr;
}
#endif
bool theory_seq::has_len_offset(expr_ref_vector const& ls, expr_ref_vector const& rs, int & offset) {
@ -399,20 +426,17 @@ bool theory_seq::branch_variable_mb() {
rational l1, l2;
for (const auto& elem : len1) l1 += elem;
for (const auto& elem : len2) l2 += elem;
if (l1 != l2) {
expr_ref l = mk_concat(e.ls);
expr_ref r = mk_concat(e.rs);
expr_ref lnl = mk_len(l), lnr = mk_len(r);
if (propagate_eq(e.dep(), lnl, lnr, false)) {
change = true;
}
continue;
}
if (split_lengths(e.dep(), e.ls, e.rs, len1, len2)) {
if (l1 == l2 && split_lengths(e.dep(), e.ls, e.rs, len1, len2)) {
TRACE("seq", tout << "split lengths\n";);
change = true;
break;
}
expr_ref l = mk_concat(e.ls);
expr_ref r = mk_concat(e.rs);
expr_ref lnl = mk_len(l), lnr = mk_len(r);
if (propagate_eq(e.dep(), lnl, lnr, false))
change = true;
}
return change;
}
@ -601,6 +625,14 @@ bool theory_seq::branch_binary_variable(depeq const& e) {
bool theory_seq::branch_unit_variable() {
bool result = false;
for (auto const& e : m_eqs) {
#if 0
eqr er(e.ls, e.rs);
m_eq_deps = e.deps;
if (m_eq.branch(0, er)) {
result = true;
break;
}
#else
if (is_unit_eq(e.ls, e.rs) &&
branch_unit_variable(e.dep(), e.ls[0], e.rs)) {
result = true;
@ -611,6 +643,7 @@ bool theory_seq::branch_unit_variable() {
result = true;
break;
}
#endif
}
CTRACE("seq", result, tout << "branch unit variable\n";);
return result;
@ -842,7 +875,9 @@ bool theory_seq::branch_quat_variable(depeq const& e) {
else if (!can_align_from_lhs(xs, ys) && !can_align_from_rhs(xs, ys))
cond = true;
if (cond) {
if (!cond)
return false;
literal_vector lits;
if (xs == ys) {
literal lit = mk_eq(mk_len(x1), mk_len(y1), false);
@ -930,33 +965,8 @@ bool theory_seq::branch_quat_variable(depeq const& e) {
return propagate_lit(dep, lits.size(), lits.c_ptr(), false_literal);
}
UNREACHABLE();
}
return false;
}
int theory_seq::find_fst_non_empty_idx(expr_ref_vector const& xs) {
for (unsigned i = 0; i < xs.size(); ++i) {
expr* x = xs[i];
if (!is_var(x)) return -1;
expr_ref e = mk_len(x);
if (ctx.e_internalized(e)) {
enode* root = ctx.get_enode(e)->get_root();
rational val;
if (m_autil.is_numeral(root->get_expr(), val) && val.is_zero()) {
continue;
}
}
return i;
}
return -1;
}
expr* theory_seq::find_fst_non_empty_var(expr_ref_vector const& x) {
int i = find_fst_non_empty_idx(x);
if (i >= 0)
return x[i];
return nullptr;
}
bool theory_seq::branch_variable_eq() {
unsigned sz = m_eqs.size();