mirrors/z3
3
0
Fork 0
mirror of https://github.com/Z3Prover/z3 synced 2026-04-27 22:33:35 +00:00
Code Activity

overflow example works

Browse source 
- introduce weak/strong eval to temper unit propagation to use only weak evaluation.
- harness the amount of interval propagation provided on overflow constraints
- weak evaluation on overflow constraints is now trivialized
- viable insertion also does conflict detection
This commit is contained in:
Nikolaj Bjorner 2024-01-04 15:55:24 -08:00
parent 5fc208cefc
commit cb672c7992
14 changed files with 122 additions and 76 deletions
Download patch file Download diff file Expand all files Collapse all files

31
src/sat/smt/polysat/viable.cpp
View file

@ -488,13 +488,15 @@ namespace polysat {
auto after = last;
unsigned bw = c.size(last.e->var);
TRACE("bv", display_explain(tout));
result.append(m_fixed_bits.explain());
if (last.e->interval.is_full()) {
if (m_var != last.e->var)
result.push_back(offset_claim(m_var, { last.e->var, 0 }));
for (auto const& sc : last.e->side_cond)
result.push_back(c.propagate(sc, c.explain_eval(sc)));
result.push_back(c.propagate(sc, c.explain_weak_eval(sc)));
result.push_back(c.get_dependency(last.e->constraint_index));
SASSERT(m_explain.size() == 1);
}
@ -510,7 +512,7 @@ namespace polysat {
if (m_var != e.e->var)
result.push_back(offset_claim(m_var, { e.e->var, 0 }));
for (auto const& sc : e.e->side_cond)
result.push_back(c.propagate(sc, c.explain_eval(sc)));
result.push_back(c.propagate(sc, c.explain_weak_eval(sc)));
result.push_back(c.get_dependency(index));
if (e.e == last.e)
break;
@ -575,7 +577,7 @@ namespace polysat {
auto sc = cs.ult(t - vlo, vhi - vlo);
SASSERT(!sc.is_always_false());
if (!sc.is_always_true())
deps.push_back(c.propagate(sc, c.explain_eval(sc)));
deps.push_back(c.propagate(sc, c.explain_weak_eval(sc)));
t.reset(lo.manager());
t = c.value(mod(e.value, rational::power_of_two(aw)), aw);
}
@ -586,19 +588,19 @@ namespace polysat {
auto sc = cs.ult(t - lo, hi - lo);
SASSERT(!sc.is_always_false());
if (!sc.is_always_true())
deps.push_back(c.propagate(sc, c.explain_eval(sc)));
deps.push_back(c.propagate(sc, c.explain_weak_eval(sc)));
}
/*
* Register constraint at index 'idx' as unitary in v.
*/
bool viable::add_unitary(pvar v, constraint_id idx) {
bool viable::add_unitary(pvar v, constraint_id idx, rational& var_value) {
if (c.is_assigned(v))
return true;
auto [sc, d, value] = c.m_constraint_index[idx.id];
SASSERT(value != l_undef);
if (value == l_false)
auto [sc, d, truth_value] = c.m_constraint_index[idx.id];
SASSERT(truth_value != l_undef);
if (truth_value == l_false)
sc = ~sc;
if (!sc.is_linear())
@ -708,6 +710,12 @@ namespace polysat {
m_var = v;
return false;
}
switch (find_viable(v, var_value)) {
case find_t::empty:
return false;
default:
break;
}
return true;
}
@ -961,6 +969,13 @@ namespace polysat {
return out;
}
std::ostream& viable::display_explain(std::ostream& out) const {
display_state(out);
for (auto const& e : m_explain)
display_one(out << e.value << " ", m_var, e.e) << "\n";
return out;
}
/*
* Lower bounds are strictly ascending.
* Intervals don't contain each-other (since lower bounds are ascending, it suffices to check containment in one direction).