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u256, separate viable_set

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2021-07-04 23:47:12 -07:00
parent aeec3bb6df
commit 04ce8ca5ef
18 changed files with 374 additions and 167 deletions
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81
src/math/polysat/viable.h
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@ -14,7 +14,51 @@ 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
@ -24,37 +68,14 @@ Notes:
#include "math/dd/dd_bdd.h"
#include "math/polysat/types.h"
#include "math/interval/mod_interval.h"
#if NEW_VIABLE
#include "math/polysat/viable_set.h"
#endif
namespace polysat {
class solver;
#if NEW_VIABLE
//
// replace BDDs by viable sets that emulate affine relations.
// viable_set has an interval of feasible values.
// it also can use ternary bit-vectors.
// or we could also just use a vector of lbool instead of ternary bit-vectors
// updating them at individual positions is relatively cheap instead of copying the
// vectors every time a range is narrowed.
//
class viable_set : public mod_interval<rational> {
unsigned m_num_bits;
rational p2() const { return rational::power_of_two(m_num_bits); }
bool is_max(rational const& a) const override;
void intersect_eq(rational const& a, bool is_positive);
bool narrow(std::function<bool(rational const&)>& eval);
public:
viable_set(unsigned num_bits): m_num_bits(num_bits) {}
~viable_set() override {}
dd::find_t find_hint(rational const& c, rational& val) const;
bool intersect_eq(rational const& a, rational const& b, bool is_positive);
bool intersect_le(rational const& a, rational const& b, rational const& c, rational const& d, bool is_positive);
rational prev(rational const& p) const;
};
#endif
class viable {
typedef dd::bdd bdd;
@ -86,8 +107,8 @@ namespace polysat {
}
};
};
vector<viable_set> m_viable;
vector<std::pair<pvar, viable_set>> m_viable_trail;
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);
@ -119,7 +140,7 @@ namespace polysat {
void push(unsigned num_bits) {
#if NEW_VIABLE
m_viable.push_back(viable_set(num_bits));
m_viable.push_back(alloc(viable_set, num_bits));
#else
m_viable.push_back(m_bdd.mk_true());
#endif