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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2021-07-02 02:48:45 -07:00
parent 05bcf0bed7
commit 788de7d614
9 changed files with 174 additions and 45 deletions
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85
src/math/polysat/viable.cpp
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@ -73,11 +73,11 @@ namespace polysat {
else if (hi == 0 && is_max(a))
hi = a;
else
std::cout << "diseq " << lo << " " << a << " " << hi << "\n";
std::cout << "unhandled diseq " << lo << " " << a << " " << hi << "\n";
}
}
void viable_set::intersect_eq(rational const& a, rational const& b, bool is_positive) {
bool viable_set::intersect_eq(rational const& a, rational const& b, bool is_positive) {
if (a.is_odd()) {
if (b == 0)
intersect_eq(b, is_positive);
@ -86,11 +86,21 @@ namespace polysat {
VERIFY(a.mult_inverse(m_num_bits, a_inv));
intersect_eq(mod(a_inv * -b, p2()), is_positive);
}
return true;
}
else {
return false;
}
else
std::cout << "intersect " << a << "*x " << " == " << b << " " << is_positive << "\n";
}
void viable_set::intersect_eq(rational const& a, rational const& b, bool is_positive, unsigned& budget) {
std::function<bool(rational const&)> eval = [&](rational const& x) {
return is_positive == (mod(a * x + b, p2()) == 0);
};
narrow(eval, budget);
}
bool viable_set::intersect_ule(rational const& a, rational const& b, rational const& c, rational const& d, bool is_positive) {
// x <= 0
if (a.is_odd() && b == 0 && c == 0 && d == 0)
@ -114,21 +124,13 @@ namespace polysat {
else
set_hi(b - 1);
}
else if (c == 0 && d == 0) {
// ax + b <= 0
// or ax + b > 0
intersect_eq(a, b, is_positive);
}
else
return false;
return true;
}
void viable_set::intersect_ule(rational const& a, rational const& b, rational const& c, rational const& d, bool is_positive, unsigned& budget) {
auto eval = [&](rational const& x) {
return is_positive == mod(a * x + b, p2()) <= mod(c * x + d, p2());
};
void viable_set::narrow(std::function<bool(rational const&)>& eval, unsigned& budget) {
while (budget > 0 && !eval(lo) && !is_max(lo) && !is_empty()) {
--budget;
lo += 1;
@ -141,6 +143,13 @@ namespace polysat {
}
}
void viable_set::intersect_ule(rational const& a, rational const& b, rational const& c, rational const& d, bool is_positive, unsigned& budget) {
std::function<bool(rational const&)> eval = [&](rational const& x) {
return is_positive == mod(a * x + b, p2()) <= mod(c * x + d, p2());
};
narrow(eval, budget);
}
void viable_set::set_hi(rational const& d) {
if (is_max(d))
return;
@ -149,9 +158,11 @@ namespace polysat {
else if (lo > d)
set_empty();
else if (hi != 0 || d + 1 < hi)
hi = d + 1;
hi = d + 1;
else if (d + 1 == hi)
return;
else
std::cout << "set hi " << lo << " " << d << " " << hi << "\n";
std::cout << "set hi " << d << " " << *this << "\n";
}
void viable_set::set_lo(rational const& b) {
@ -161,8 +172,10 @@ namespace polysat {
lo = b, hi = 0;
else if (lo < b)
lo = b;
else if (lo == b)
return;
else
std::cout << "set lo " << lo << " " << b << " " << hi << "\n";
std::cout << "set lo " << b << " " << *this << "\n";
}
#endif
@ -187,7 +200,15 @@ namespace polysat {
void viable::intersect_eq(rational const& a, pvar v, rational const& b, bool is_positive) {
#if NEW_VIABLE
push_viable(v);
m_viable[v].intersect_eq(a, b, is_positive);
if (!m_viable[v].intersect_eq(a, b, is_positive)) {
IF_VERBOSE(10, verbose_stream() << "could not intersect v" << v << " " << m_viable[v] << "\n");
unsigned budget = 10;
m_viable[v].intersect_eq(a, b, is_positive, budget);
if (budget == 0) {
std::cout << "budget used\n";
// then narrow the range using BDDs
}
}
if (m_viable[v].is_empty())
s.set_conflict(v);
#else
@ -218,6 +239,9 @@ namespace polysat {
void viable::intersect_ule(pvar v, rational const& a, rational const& b, rational const& c, rational const& d, bool is_positive) {
#if NEW_VIABLE
//
// TODO This code needs to be partitioned into self-contained pieces.
//
push_viable(v);
if (!m_viable[v].intersect_ule(a, b, c, d, is_positive)) {
unsigned budget = 10;
@ -235,15 +259,30 @@ namespace polysat {
other = alloc(ineq_entry, sz, a, b, c, d, le);
m_ineq_cache.insert(other);
}
le = is_positive ? other->repr : !other->repr;
bdd gt = is_positive ? !other->repr : other->repr;
other->m_activity++;
//
// instead of using activity for GC, use the Move-To-Front approach
// see sat/smt/bv_ackerman.h or sat/smt/euf_ackerman.h
// where hash table entries use a dll_base.
//
// le(lo) is false: find min x >= lo, such that le(x) is false, le(x+1) is true
// le(hi) is false: find max x =< hi, such that le(x) is false, le(x-1) is true
// bdd x_is_lo = m.mk_num(sz, m_viable[v].lo) == var2bits(v).var();
// bdd lo_is_sat = x_is_lo && lo;
// if (lo_is_sat.is_false())
// find_min_above(lo, le);
rational bound = m_viable[v].lo;
if (var2bits(v).sup(gt, bound)) {
m_viable[v].set_lo(bound);
m_viable[v].set_ne(bound);
}
bound = m_viable[v].hi;
if (bound != 0) {
bound = bound - 1;
if (var2bits(v).inf(gt, bound)) {
std::cout << "TODO: new upper bound " << bound << "\n";
}
}
}
@ -285,8 +324,8 @@ namespace polysat {
void viable::add_non_viable(pvar v, rational const& val) {
#if NEW_VIABLE
push_viable(v);
IF_VERBOSE(10, verbose_stream() << " v" << v << " != " << val << "\n");
m_viable[v].set_ne(val);
std::cout << " v" << v << " != " << val << "\n";
if (m_viable[v].is_empty())
s.set_conflict(v);
#else