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add ite reduction to canonizer, remove it from ad-hoc routine

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2016-05-18 09:58:34 -07:00
parent cc3bfe8da2
commit 85be486c1e
2 changed files with 25 additions and 42 deletions
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66
src/smt/theory_seq.cpp
View file

@ -1820,22 +1820,16 @@ bool theory_seq::solve_ne(unsigned idx) {
TRACE("seq", display_disequation(tout << "reduces to false: ", n););
return true;
}
else if (!change) {
TRACE("seq", tout << "no change " << n.ls(i) << " " << n.rs(i) << "\n";);
if (updated) {
new_ls.push_back(n.ls(i));
new_rs.push_back(n.rs(i));
}
continue;
}
else {
// eliminate ite expressions.
reduce_ite(lhs, new_lits, num_undef_lits, change);
reduce_ite(rhs, new_lits, num_undef_lits, change);
reduce_ite(ls, new_lits, num_undef_lits, change);
reduce_ite(rs, new_lits, num_undef_lits, change);
if (!change) {
TRACE("seq", tout << "no change " << n.ls(i) << " " << n.rs(i) << "\n";);
if (updated) {
new_ls.push_back(n.ls(i));
new_rs.push_back(n.rs(i));
}
continue;
}
if (!updated) {
for (unsigned j = 0; j < i; ++j) {
@ -1940,32 +1934,6 @@ bool theory_seq::solve_ne(unsigned idx) {
return updated;
}
void theory_seq::reduce_ite(expr_ref_vector & ls, literal_vector& new_lits, unsigned& num_undef_lits, bool& change) {
expr* cond, *th, *el;
context& ctx = get_context();
for (unsigned i = 0; i < ls.size(); ++i) {
expr* e = ls[i].get();
if (m.is_ite(e, cond, th, el)) {
literal lit(mk_literal(cond));
switch (ctx.get_assignment(lit)) {
case l_true:
change = true;
new_lits.push_back(lit);
ls[i] = th;
break;
case l_false:
change = true;
new_lits.push_back(~lit);
ls[i] = el;
break;
case l_undef:
++num_undef_lits;
break;
}
}
}
}
bool theory_seq::solve_nc(unsigned idx) {
nc const& n = m_ncs[idx];
@ -2613,6 +2581,7 @@ expr_ref theory_seq::expand(expr* e0, dependency*& eqs) {
}
expr* e = m_rep.find(e0, deps);
expr* e1, *e2, *e3;
context& ctx = get_context();
if (m_util.str.is_concat(e, e1, e2)) {
result = mk_concat(expand(e1, deps), expand(e2, deps));
}
@ -2637,11 +2606,26 @@ expr_ref theory_seq::expand(expr* e0, dependency*& eqs) {
else if (m_util.str.is_index(e, e1, e2, e3)) {
result = m_util.str.mk_index(expand(e1, deps), expand(e2, deps), e3);
}
else if (m.is_ite(e, e1, e2, e3)) {
literal lit(mk_literal(e1));
switch (ctx.get_assignment(lit)) {
case l_true:
deps = m_dm.mk_join(deps, m_dm.mk_leaf(assumption(lit)));
result = expand(e2, deps);
break;
case l_false:
deps = m_dm.mk_join(deps, m_dm.mk_leaf(assumption(~lit)));
result = expand(e3, deps);
break;
case l_undef:
result = e;
break;
}
}
else if (m_util.str.is_itos(e, e1)) {
rational val;
if (get_value(e1, val)) {
expr_ref num(m), res(m);
context& ctx = get_context();
num = m_autil.mk_numeral(val, true);
if (!ctx.e_internalized(num)) {
ctx.internalize(num, false);

1
src/smt/theory_seq.h
View file

@ -410,7 +410,6 @@ namespace smt {
bool solve_nqs(unsigned i);
bool solve_ne(unsigned i);
bool solve_nc(unsigned i);
void reduce_ite(expr_ref_vector& ls, literal_vector& new_lits, unsigned& num_undef_lits, bool& change);
struct cell {
cell* m_parent;