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This commit is contained in:
Nikolaj Bjorner 2022-08-21 15:19:51 -07:00
parent 56fb161532
commit 2181a0ff74

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@ -561,17 +561,9 @@ namespace smt {
void theory_arith<Ext>::mk_idiv_mod_axioms(expr * dividend, expr * divisor) {
th_rewriter & s = ctx.get_rewriter();
if (!m_util.is_zero(divisor)) {
auto mk_mul = [&](expr* a, expr* b) {
if (m_util.is_mul(a)) {
ptr_vector<expr> args(to_app(a)->get_num_args(), to_app(a)->get_args());
args.push_back(b);
return m_util.mk_mul(args.size(), args.data());
}
return m_util.mk_mul(a, b);
};
// if divisor is zero, then idiv and mod are uninterpreted functions.
expr_ref div(m), mod(m), zero(m), abs_divisor(m), one(m);
expr_ref eqz(m), eq(m), lower(m), upper(m), qr(m), le(m), ge(m);
expr_ref eqz(m), eq(m), lower(m), upper(m), qr(m), qr1(m), le(m), ge(m);
div = m_util.mk_idiv(dividend, divisor);
mod = m_util.mk_mod(dividend, divisor);
zero = m_util.mk_int(0);
@ -579,7 +571,7 @@ namespace smt {
abs_divisor = m_util.mk_sub(m.mk_ite(m_util.mk_lt(divisor, zero), m_util.mk_sub(zero, divisor), divisor), one);
s(abs_divisor);
eqz = m.mk_eq(divisor, zero);
qr = m_util.mk_add(mk_mul(divisor, div), mod);
qr = m_util.mk_add(m_util.mk_mul(divisor, div), mod);
eq = m.mk_eq(qr, dividend);
lower = m_util.mk_ge(mod, zero);
upper = m_util.mk_le(mod, abs_divisor);
@ -589,16 +581,22 @@ namespace smt {
tout << "lower: " << lower << "\n";
tout << "upper: " << upper << "\n";);
le = m_util.mk_le(m_util.mk_sub(qr, dividend), zero);
ge = m_util.mk_ge(m_util.mk_sub(qr, dividend), zero);
mk_axiom(eqz, le, false);
mk_axiom(eqz, ge, false);
mk_axiom(eqz, eq, false);
mk_axiom(eqz, lower, false);
mk_axiom(eqz, upper, !m_util.is_numeral(abs_divisor));
rational k;
// m_arith_eq_adapter.mk_axioms(ensure_enode(qr), ensure_enode(dividend));
m_arith_eq_adapter.mk_axioms(ensure_enode(qr), ensure_enode(dividend));
// non-linear divisors/mod have to be flattened for the non-linear solver to understand the terms.
// to ensure this use the rewriter.
qr1 = qr;
s(qr1);
if (qr != qr1) {
mk_axiom(m.mk_eq(qr, qr1), false);
m_arith_eq_adapter.mk_axioms(ensure_enode(qr), ensure_enode(qr1));
}
if (m_util.is_zero(dividend)) {
mk_axiom(eqz, m.mk_eq(div, zero));