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quot_rem note

This commit is contained in:
Jakob Rath 2022-12-01 14:11:37 +01:00
parent bcde2844b2
commit 57edd12e36

View file

@ -275,6 +275,7 @@ namespace polysat {
return ult(a + shift, b + shift);
}
/** unsigned quotient/remainder */
std::pair<pdd, pdd> constraint_manager::quot_rem(pdd const& a, pdd const& b) {
auto& m = a.manager();
unsigned sz = m.power_of_2();
@ -282,6 +283,9 @@ namespace polysat {
// By SMT-LIB specification, b = 0 ==> q = -1, r = a.
return {m.mk_val(m.max_value()), a};
}
if (b.is_one()) {
return {a, m.zero()};
}
if (a.is_val() && b.is_val()) {
rational const av = a.val();
rational const bv = b.val();
@ -296,6 +300,13 @@ namespace polysat {
SASSERT(r.val() < b.val());
return {std::move(q), std::move(r)};
}
#if 0
unsigned pow;
if (b.is_val() && b.val().is_power_of_two(pow)) {
// TODO: q = a >> b.val()
// r = 0 \circ a[pow:] ???
}
#endif
constraint_dedup::quot_rem_args args({a, b});
auto it = m_dedup.quot_rem_expr.find_iterator(args);
if (it != m_dedup.quot_rem_expr.end())