void tactic2solver::pop_core(unsigned n) {
unsigned new_lvl = m_scopes.size() - n;
unsigned old_sz = m_scopes[new_lvl];
m_assertions.shrink(old_sz);
m_scopes.shrink(new_lvl);
m_result = 0;
}
bool detect_equivalences(expr_ref_vector& v, bool inside_disjunction)
{
bool have_pair = false;
unsigned prev_pair_idx = 0;
arg_pair ap;
unsigned read_idx = 0;
unsigned write_idx = 0;
while(read_idx<v.size()) {
expr * e = v[read_idx].get();
arg_pair new_ap;
if (match_arg_pair(e, new_ap, inside_disjunction)) {
app * neq = nullptr;
if (have_pair) {
neq = detect_equivalence(ap, new_ap, inside_disjunction);
}
if (neq) {
have_pair = false;
v[prev_pair_idx] = neq;
read_idx++;
continue;
}
else {
have_pair = true;
prev_pair_idx = write_idx;
ap = new_ap;
}
}
else {
have_pair = false;
}
if (write_idx!=read_idx) {
v[write_idx] = e;
}
read_idx++;
write_idx++;
}
v.shrink(write_idx);
return read_idx!=write_idx;
}
static void remove_duplicates(expr_ref_vector& v)
{
expr * a = v[0].get();
unsigned read_idx = 1;
unsigned write_idx = 1;
for (;;) {
while(read_idx<v.size() && a==v[read_idx].get()) {
read_idx++;
}
if (read_idx==v.size()) {
break;
}
a = v[read_idx].get();
if (write_idx!=read_idx) {
v[write_idx] = a;
}
write_idx++;
read_idx++;
}
v.shrink(write_idx);
}
/**
Factors input vector v into equivalence classes and the rest
*/
void factor_eqs(expr_ref_vector &v, expr_equiv_class &equiv) {
ast_manager &m = v.get_manager();
arith_util arith(m);
expr *e1 = 0, *e2 = 0;
flatten_and(v);
unsigned j = 0;
for (unsigned i = 0; i < v.size(); ++i) {
if (m.is_eq(v.get(i), e1, e2)) {
if (arith.is_zero(e1)) {
std::swap(e1, e2);
}
// y + -1*x == 0
expr* a0 = 0, *a1 = 0, *x = 0;
if (arith.is_zero(e2) && arith.is_add(e1, a0, a1)) {
if (arith.is_times_minus_one(a1, x)) {
e1 = a0;
e2 = x;
}
else if (arith.is_times_minus_one(a0, x)) {
e1 = a1;
e2 = x;
}
}
equiv.merge(e1, e2);
}
else {
if (j < i) {
v[j] = v.get(i);
}
j++;
}
}
v.shrink(j);
}
