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Simplify constraint evaluation

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This commit is contained in:
Jakob Rath 2022-11-23 12:19:03 +01:00
parent e4999b07aa
commit fdc186b204
10 changed files with 95 additions and 113 deletions
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48
src/math/polysat/umul_ovfl_constraint.cpp
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@ -40,15 +40,15 @@ namespace polysat {
case l_true: return display(out);
case l_false: return display(out << "~");
case l_undef: return display(out << "?");
}
}
return out;
}
std::ostream& umul_ovfl_constraint::display(std::ostream& out) const {
return out << "ovfl*(" << m_p << ", " << m_q << ")";
return out << "ovfl*(" << m_p << ", " << m_q << ")";
}
lbool umul_ovfl_constraint::eval(pdd const& p, pdd const& q) const {
lbool umul_ovfl_constraint::eval(pdd const& p, pdd const& q) {
if (p.is_zero() || q.is_zero() || p.is_one() || q.is_one())
return l_false;
@ -61,30 +61,18 @@ namespace polysat {
return l_undef;
}
bool umul_ovfl_constraint::is_always_false(bool is_positive, pdd const& p, pdd const& q) const {
switch (eval(p, q)) {
case l_true: return !is_positive;
case l_false: return is_positive;
default: return false;
}
lbool umul_ovfl_constraint::eval() const {
return eval(p(), q());
}
bool umul_ovfl_constraint::is_always_true(bool is_positive, pdd const& p, pdd const& q) const {
return is_always_false(!is_positive, p, q);
lbool umul_ovfl_constraint::eval(assignment const& a) const {
return eval(a.apply_to(p()), a.apply_to(q()));
}
bool umul_ovfl_constraint::is_always_false(bool is_positive) const {
return is_always_false(is_positive, m_p, m_q);
}
bool umul_ovfl_constraint::is_currently_false(assignment const& a, bool is_positive) const {
return is_always_false(is_positive, a.apply_to(p()), a.apply_to(q()));
}
void umul_ovfl_constraint::narrow(solver& s, bool is_positive, bool first) {
void umul_ovfl_constraint::narrow(solver& s, bool is_positive, bool first) {
auto p1 = s.subst(p());
auto q1 = s.subst(q());
if (is_always_false(is_positive, p1, q1)) {
s.set_conflict({ this, is_positive });
return;
@ -94,19 +82,19 @@ namespace polysat {
if (try_viable(s, is_positive, p(), q(), p1, q1))
return;
if (narrow_bound(s, is_positive, p(), q(), p1, q1))
return;
if (narrow_bound(s, is_positive, q(), p(), q1, p1))
return;
}
/**
* if p constant, q, propagate inequality
*/
bool umul_ovfl_constraint::narrow_bound(solver& s, bool is_positive,
* if p constant, q, propagate inequality
*/
bool umul_ovfl_constraint::narrow_bound(solver& s, bool is_positive,
pdd const& p0, pdd const& q0, pdd const& p, pdd const& q) {
if (!p.is_val())
@ -118,13 +106,13 @@ namespace polysat {
auto bound = ceil((max + 1) / p.val());
//
// the clause that explains bound <= q or bound > q
//
// the clause that explains bound <= q or bound > q
//
// Ovfl(p, q) & p <= p.val() => q >= bound
// ~Ovfl(p, q) & p >= p.val() => q < bound
// ~Ovfl(p, q) & p >= p.val() => q < bound
//
signed_constraint sc(this, is_positive);
signed_constraint sc(this, is_positive);
signed_constraint premise = is_positive ? s.ule(p0, p.val()) : s.ule(p.val(), p0);
signed_constraint conseq = is_positive ? s.ule(bound, q0) : s.ult(q0, bound);