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adding new viable using forbidden intervals

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2021-11-10 08:23:45 -08:00
parent 733f44d141
commit 0bec8520e1
9 changed files with 201 additions and 254 deletions
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96
src/math/polysat/viable.h
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@ -14,63 +14,15 @@ Author:
Notes:
NEW_VIABLE uses cheaper book-keeping, but is partial.
Alternative to using rational, instead use fixed-width numerals.
map from num_bits to template set
class viable_trail_base {
public:
virtual pop(pvar v) = 0;
virtual push(pvar v) = 0;
static viable_trail_base* mk_trail(unsigned num_bits);
};
class viable_trail<Numeral> : public viable_trail_base {
vector<viable_set<Numeral>> m_viable;
vector<viable_set<Numeral>> m_trail;
public:
void pop(pvar v) override {
m_viable[v] = m_trail.back();
m_trail.pop_back();
}
void push(pvar v) override {
m_trail.push_back(m_viable[v]);
}
};
// from num-bits to viable_trail_base*
scoped_ptr_vector<viable_trail_base> m_viable_trails;
viable_set_base& to_viable(pvar v) {
return (*m_viable_trails[num_bits(v)])[v];
}
viable_set_base is required to expose functions:
lo, hi,
prev, next alternative as bit-vectors
update_lo (a)
update_hi (a)
intersect_le (a, b, c, d)
intersect_diff (a, b)
intersect_eq (a, b)
is_empty
contains
--*/
#pragma once
#define NEW_VIABLE 0
#include <limits>
#include "math/dd/dd_bdd.h"
#include "math/polysat/types.h"
#if NEW_VIABLE
#include "math/polysat/viable_set.h"
#endif
namespace polysat {
@ -82,43 +34,7 @@ namespace polysat {
typedef dd::fdd fdd;
solver& s;
dd::bdd_manager m_bdd;
scoped_ptr_vector<dd::fdd> m_bits;
#if NEW_VIABLE
struct cached_constraint {
enum op_code { is_ule, is_eq };
op_code m_op;
unsigned m_num_bits;
rational a, b, c, d;
bdd repr;
unsigned m_activity = 0;
cached_constraint(unsigned n, rational const& a, rational const& b, rational const& c, rational const& d, bdd& f) :
m_op(op_code::is_ule), m_num_bits(n), a(a), b(b), c(c), d(d), repr(f) {}
cached_constraint(unsigned n, rational const& a, rational const& b, bdd& f) :
m_op(op_code::is_eq), m_num_bits(n), a(a), b(b), repr(f) {}
struct hash {
unsigned operator()(cached_constraint const* e) const {
return mk_mix(e->a.hash(), e->b.hash(), mk_mix(e->c.hash(), e->d.hash(), e->m_num_bits)) + e->m_op;
}
};
struct eq {
bool operator()(cached_constraint const* x, cached_constraint const* y) const {
return x->m_op == y->m_op && x->a == y->a && x->b == y->b && x->c == y->c && x->d == y->d && x->m_num_bits == y->m_num_bits;
}
};
};
scoped_ptr_vector<viable_set> m_viable;
vector<std::pair<pvar, viable_set*>> m_viable_trail;
hashtable<cached_constraint*, cached_constraint::hash, cached_constraint::eq> m_constraint_cache;
void intersect_ule_bdd(pvar v, rational const& a, rational const& b, rational const& c, rational const& d, bool is_positive);
void intersect_eq_bdd(pvar v, rational const& a, rational const& b, bool is_positive);
cached_constraint& cache_constraint(pvar v, cached_constraint& entry0, std::function<bdd(void)>& mk_constraint);
void gc_cached_constraints();
void narrow(pvar v, bdd const& is_false);
#else
scoped_ptr_vector<dd::fdd> m_bits;
vector<bdd> m_viable; // set of viable values.
vector<std::pair<pvar, bdd>> m_viable_trail;
@ -127,7 +43,7 @@ namespace polysat {
* Register all values that are not contained in vals as non-viable.
*/
void intersect_viable(pvar v, bdd vals);
#endif
dd::bdd_manager& get_bdd() { return m_bdd; }
dd::fdd const& sz2bits(unsigned sz);
dd::fdd const& var2bits(pvar v);
@ -139,11 +55,7 @@ namespace polysat {
~viable();
void push(unsigned num_bits) {
#if NEW_VIABLE
m_viable.push_back(alloc(viable_set, num_bits));
#else
m_viable.push_back(m_bdd.mk_true());
#endif
}
void pop() {