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working on pb solver

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2013-11-16 17:01:43 -08:00
parent 06073db413
commit 77cdb2bcde
3 changed files with 343 additions and 221 deletions
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56
src/smt/theory_pb.h
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@ -28,7 +28,8 @@ namespace smt {
class theory_pb : public theory {
struct sort_expr;
typedef svector<std::pair<literal, int> > arg_t;
typedef int64 numeral;
typedef svector<std::pair<literal, numeral> > arg_t;
struct stats {
unsigned m_num_axioms;
@ -44,24 +45,52 @@ namespace smt {
app* m_app;
literal m_lit; // literal repesenting predicate
arg_t m_args; // encode args[0]*coeffs[0]+...+args[n-1]*coeffs[n-1] >= m_k;
int m_k; // invariants: m_k > 0, coeffs[i] > 0
numeral m_k; // invariants: m_k > 0, coeffs[i] > 0
// Watch the first few positions until the sum satisfies:
// sum coeffs[i] >= m_lower + max_coeff
int m_max_coeff; // maximal coefficient.
numeral m_max_coeff; // maximal coefficient.
unsigned m_watch_sz; // number of literals being watched.
numeral m_sum; // sum of coefficients so far.
numeral m_max_sum; // maximal sum of watch literals.
unsigned m_num_propagations;
unsigned m_compilation_threshold;
bool m_compiled;
lbool m_compiled;
ineq(app* a, literal l):
m_app(a),
m_lit(l),
m_lit(l),
m_max_coeff(0),
m_watch_sz(0),
m_sum(0),
m_max_sum(0),
m_num_propagations(0),
m_compilation_threshold(UINT_MAX),
m_compiled(false)
m_compiled(l_false)
{}
literal lit() const { return m_lit; }
numeral const & k() const { return m_k; }
literal lit(unsigned i) const { return m_args[i].first; }
numeral const & coeff(unsigned i) const { return m_args[i].second; }
unsigned size() const { return m_args.size(); }
numeral const& sum() const { return m_sum; }
numeral const& max_sum() const { return m_max_sum; }
numeral const& max_coeff() const { return m_max_coeff; }
unsigned watch_size() const { return m_watch_sz; }
unsigned find_lit(bool_var v, unsigned begin, unsigned end) {
while (lit(begin).var() != v) {
++begin;
SASSERT(begin < end);
}
return begin;
}
};
typedef ptr_vector<ineq> watch_list;
@ -73,12 +102,16 @@ namespace smt {
literal_vector m_literals; // temporary vector
card_util m_util;
stats m_stats;
ptr_vector<ineq> m_to_compile; // inequalities to compile.
// internalize_atom:
lbool normalize_ineq(arg_t& args, int& k);
lbool normalize_ineq(arg_t& args, numeral& k);
static numeral gcd(numeral a, numeral b);
literal compile_arg(expr* arg);
void add_watch(literal l, ineq* c);
void add_watch(ineq& c, unsigned index);
void del_watch(watch_list& watch, unsigned index, ineq& c, unsigned ineq_index);
void assign_watch(bool_var v, bool is_true, watch_list& watch, unsigned index);
void assign_ineq(ineq& c);
std::ostream& display(std::ostream& out, ineq& c) const;
@ -86,12 +119,15 @@ namespace smt {
void add_assign(ineq& c, literal_vector const& lits, literal l);
literal_vector& get_lits();
literal_vector& get_helpful_literals(ineq& c, bool negate);
literal_vector& get_unhelpful_literals(ineq& c, bool negate);
//
// Utilities to compile cardinality
// constraints into a sorting network.
//
void compile_ineq(ineq& c);
bool should_compile(ineq& c);
void inc_propagations(ineq& c);
unsigned get_compilation_threshold(ineq& c);
public:
theory_pb(ast_manager& m);
@ -112,7 +148,9 @@ namespace smt {
virtual void init_search_eh();
virtual void push_scope_eh();
virtual void pop_scope_eh(unsigned num_scopes);
virtual void restart_eh();
virtual void collect_statistics(::statistics & st) const;
};
};