mirrors/z3
3
0
Fork 0
mirror of https://github.com/Z3Prover/z3 synced 2025-04-14 04:48:45 +00:00
Code Activity

compile constants into different variables instead of reusing a single variable 1 and coefficients. It delays introducing large coefficients and allows more efficient bounds propagation

Browse source 
Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2023-06-20 16:09:34 -07:00
parent 32ec02778e
commit eb1caee18a
1 changed files with 45 additions and 53 deletions

98
src/smt/theory_lra.cpp
View file

@ -90,13 +90,11 @@ class theory_lra::imp {
expr_ref_vector m_terms;
vector<rational> m_coeffs;
svector<theory_var> m_vars;
rational m_offset;
ptr_vector<expr> m_to_ensure_enode, m_to_ensure_var;
internalize_state(ast_manager& m): m_terms(m) {}
void reset() {
m_terms.reset();
m_coeffs.reset();
m_offset.reset();
m_vars.reset();
m_to_ensure_enode.reset();
m_to_ensure_var.reset();
@ -123,7 +121,6 @@ class theory_lra::imp {
expr_ref_vector& terms() { return m_st.m_terms; }
vector<rational>& coeffs() { return m_st.m_coeffs; }
svector<theory_var>& vars() { return m_st.m_vars; }
rational& offset() { return m_st.m_offset; }
ptr_vector<expr>& to_ensure_enode() { return m_st.m_to_ensure_enode; }
ptr_vector<expr>& to_ensure_var() { return m_st.m_to_ensure_var; }
void push(expr* e, rational c) { m_st.m_terms.push_back(e); m_st.m_coeffs.push_back(c); }
@ -345,18 +342,33 @@ class theory_lra::imp {
st.push(rhs, rational::minus_one());
linearize(st);
}
theory_var internalize_numeral(app* n, rational const& val) {
if (!ctx().e_internalized(n))
mk_enode(n);
theory_var v = mk_var(n);
lpvar vi = get_lpvar(v);
if (vi == UINT_MAX) {
vi = lp().add_var(v, a.is_int(n));
add_def_constraint_and_equality(vi, lp::GE, val);
add_def_constraint_and_equality(vi, lp::LE, val);
register_fixed_var(v, val);
}
return v;
}
void linearize(scoped_internalize_state& st) {
expr_ref_vector & terms = st.terms();
svector<theory_var>& vars = st.vars();
vector<rational>& coeffs = st.coeffs();
rational& offset = st.offset();
rational r;
expr* n1, *n2;
unsigned index = 0;
while (index < terms.size()) {
SASSERT(index >= vars.size());
expr* n = terms[index].get();
expr* n = terms.get(index);
st.to_ensure_enode().push_back(n);
if (a.is_add(n)) {
for (expr* arg : *to_app(n)) {
@ -394,7 +406,9 @@ class theory_lra::imp {
++index;
}
else if (a.is_numeral(n, r)) {
offset += coeffs[index]*r;
theory_var v = internalize_numeral(to_app(n), r);
coeffs[vars.size()] = coeffs[index];
vars.push_back(v);
++index;
}
else if (a.is_uminus(n, n1)) {
@ -781,16 +795,9 @@ class theory_lra::imp {
}
bool is_unit_var(scoped_internalize_state& st) {
return st.offset().is_zero() && st.vars().size() == 1 && st.coeffs()[0].is_one();
return st.vars().size() == 1 && st.coeffs()[0].is_one();
}
bool is_one(scoped_internalize_state& st) {
return st.offset().is_one() && st.vars().empty();
}
bool is_zero(scoped_internalize_state& st) {
return st.offset().is_zero() && st.vars().empty();
}
theory_var internalize_def(app* term, scoped_internalize_state& st) {
TRACE("arith", tout << expr_ref(term, m) << "\n";);
@ -841,46 +848,29 @@ class theory_lra::imp {
theory_var v = mk_var(term);
TRACE("arith", tout << mk_bounded_pp(term, m) << " v" << v << "\n";);
if (is_unit_var(st) && v == st.vars()[0]) {
if (is_unit_var(st) && v == st.vars()[0])
return st.vars()[0];
}
else if (is_one(st) && a.is_numeral(term)) {
return lp().local_to_external(get_one(a.is_int(term)));
}
else if (is_zero(st) && a.is_numeral(term)) {
return lp().local_to_external(get_zero(a.is_int(term)));
}
else {
init_left_side(st);
lpvar vi = get_lpvar(v);
if (vi == UINT_MAX) {
if (m_left_side.empty()) {
vi = lp().add_var(v, a.is_int(term));
add_def_constraint_and_equality(vi, lp::GE, st.offset());
add_def_constraint_and_equality(vi, lp::LE, st.offset());
register_fixed_var(v, st.offset());
return v;
}
if (!st.offset().is_zero()) {
m_left_side.push_back(std::make_pair(st.offset(), get_one(a.is_int(term))));
}
if (m_left_side.empty()) {
vi = lp().add_var(v, a.is_int(term));
add_def_constraint_and_equality(vi, lp::GE, rational(0));
add_def_constraint_and_equality(vi, lp::LE, rational(0));
}
else {
vi = lp().add_term(m_left_side, v);
SASSERT(lp::tv::is_term(vi));
TRACE("arith_verbose",
tout << "v" << v << " := " << mk_pp(term, m)
<< " slack: " << vi << " scopes: " << m_scopes.size() << "\n";
lp().print_term(lp().get_term(lp::tv::raw(vi)), tout) << "\n";);
}
}
return v;
init_left_side(st);
lpvar vi = get_lpvar(v);
if (vi == UINT_MAX) {
if (m_left_side.empty()) {
vi = lp().add_var(v, a.is_int(term));
add_def_constraint_and_equality(vi, lp::GE, rational(0));
add_def_constraint_and_equality(vi, lp::LE, rational(0));
}
else {
vi = lp().add_term(m_left_side, v);
SASSERT(lp::tv::is_term(vi));
TRACE("arith_verbose",
tout << "v" << v << " := " << mk_pp(term, m)
<< " slack: " << vi << " scopes: " << m_scopes.size() << "\n";
lp().print_term(lp().get_term(lp::tv::raw(vi)), tout) << "\n";);
}
}
return v;
}
@ -3211,11 +3201,13 @@ public:
void fixed_var_eh(theory_var v, lp::tv t, lp::constraint_index ci1, lp::constraint_index ci2, rational const& bound) {
theory_var w = null_theory_var;
enode* x = get_enode(v);
if (bound.is_zero())
if (m_value2var.find(bound, w))
;
else if (bound.is_zero())
w = lp().local_to_external(get_zero(a.is_int(x->get_expr())));
else if (bound.is_one())
w = lp().local_to_external(get_one(a.is_int(x->get_expr())));
else if (!m_value2var.find(bound, w))
else
return;
enode* y = get_enode(w);
if (x->get_sort() != y->get_sort())