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z3/lib/sat_simplifier.h
Leonardo de Moura e9eab22e5c Z3 sources
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2012-10-02 11:35:25 -07:00

189 lines
6.5 KiB
C++

/*++
Copyright (c) 2011 Microsoft Corporation
Module Name:
sat_simplifier.h
Abstract:
SAT simplification procedures that use a "full" occurrence list:
Subsumption, Blocked Clause Removal, Variable Elimination, ...
Author:
Leonardo de Moura (leonardo) 2011-05-24.
Revision History:
--*/
#ifndef _SAT_SIMPLIFIER_H_
#define _SAT_SIMPLIFIER_H_
#include"sat_types.h"
#include"sat_clause.h"
#include"sat_clause_set.h"
#include"sat_clause_use_list.h"
#include"sat_watched.h"
#include"sat_model_converter.h"
#include"heap.h"
#include"statistics.h"
#include"params.h"
namespace sat {
class solver;
class use_list {
vector<clause_use_list> m_use_list;
public:
void init(unsigned num_vars);
void insert(clause & c);
void erase(clause & c);
void erase(clause & c, literal l);
clause_use_list & get(literal l) { return m_use_list[l.index()]; }
clause_use_list const & get(literal l) const { return m_use_list[l.index()]; }
void finalize() { m_use_list.finalize(); }
};
class simplifier {
solver & s;
unsigned m_num_calls;
use_list m_use_list;
clause_set m_sub_todo;
svector<bin_clause> m_sub_bin_todo;
unsigned m_last_sub_trail_sz; // size of the trail since last cleanup
bool_var_set m_elim_todo;
bool m_need_cleanup;
tmp_clause m_dummy;
// simplifier extra variable fields.
svector<char> m_visited; // transient
// counters
int m_sub_counter;
int m_elim_counter;
// config
bool m_elim_blocked_clauses;
unsigned m_elim_blocked_clauses_at;
unsigned m_blocked_clause_limit;
bool m_resolution;
unsigned m_res_limit;
unsigned m_res_occ_cutoff;
unsigned m_res_occ_cutoff1;
unsigned m_res_occ_cutoff2;
unsigned m_res_occ_cutoff3;
unsigned m_res_lit_cutoff1;
unsigned m_res_lit_cutoff2;
unsigned m_res_lit_cutoff3;
unsigned m_res_cls_cutoff1;
unsigned m_res_cls_cutoff2;
bool m_subsumption;
unsigned m_subsumption_limit;
// stats
unsigned m_num_blocked_clauses;
unsigned m_num_subsumed;
unsigned m_num_elim_vars;
unsigned m_num_sub_res;
unsigned m_num_elim_lits;
struct size_lt {
bool operator()(clause const * c1, clause const * c2) const { return c1->size() > c2->size(); }
};
void checkpoint();
void init_visited();
void mark_visited(literal l) { m_visited[l.index()] = true; }
void unmark_visited(literal l) { m_visited[l.index()] = false; }
bool is_marked(literal l) const { return m_visited[l.index()] != 0; }
void mark_all_but(clause const & c, literal l);
void unmark_all(clause const & c);
void register_clauses(clause_vector & cs);
void remove_clause_core(clause & c);
void remove_clause(clause & c);
void remove_clause(clause & c, literal l);
void remove_bin_clause_half(literal l1, literal l2, bool learned);
bool_var get_min_occ_var(clause const & c) const;
bool subsumes1(clause const & c1, clause const & c2, literal & l);
void collect_subsumed1_core(clause const & c, clause_vector & out, literal_vector & out_lits, literal target);
void collect_subsumed1(clause const & c, clause_vector & out, literal_vector & out_lits);
clause_vector m_bs_cs;
literal_vector m_bs_ls;
void back_subsumption1(clause & c);
void back_subsumption1(literal l1, literal l2, bool learned);
literal get_min_occ_var0(clause const & c) const;
bool subsumes0(clause const & c1, clause const & c2);
void collect_subsumed0_core(clause const & c1, clause_vector & out, literal target);
void collect_subsumed0(clause const & c1, clause_vector & out);
void back_subsumption0(clause & c1);
bool cleanup_clause(clause & c);
bool cleanup_clause(literal_vector & c);
void propagate_unit(literal l);
void elim_lit(clause & c, literal l);
void elim_dup_bins();
bool subsume_with_binaries();
void mark_as_not_learned_core(watch_list & wlist, literal l2);
void mark_as_not_learned(literal l1, literal l2);
void subsume();
void cleanup_watches();
void cleanup_clauses(clause_vector & cs, bool learned, bool vars_eliminated);
bool is_external(bool_var v) const;
bool was_eliminated(bool_var v) const;
lbool value(bool_var v) const;
lbool value(literal l) const;
watch_list & get_wlist(literal l);
watch_list const & get_wlist(literal l) const;
struct blocked_clause_elim;
void elim_blocked_clauses();
unsigned get_num_non_learned_bin(literal l) const;
unsigned get_to_elim_cost(bool_var v) const;
void order_vars_for_elim(bool_var_vector & r);
void collect_clauses(literal l, clause_wrapper_vector & r);
clause_wrapper_vector m_pos_cls;
clause_wrapper_vector m_neg_cls;
literal_vector m_new_cls;
bool resolve(clause_wrapper const & c1, clause_wrapper const & c2, literal l, literal_vector & r);
void save_clauses(model_converter::entry & mc_entry, clause_wrapper_vector const & cs);
void add_non_learned_binary_clause(literal l1, literal l2);
void remove_bin_clauses(literal l);
void remove_clauses(clause_use_list const & cs, literal l);
bool try_eliminate(bool_var v);
void elim_vars();
struct blocked_cls_report;
struct subsumption_report;
struct elim_var_report;
public:
simplifier(solver & s, params_ref const & p);
~simplifier();
void insert_todo(bool_var v) { m_elim_todo.insert(v); }
void operator()(bool learned);
void updt_params(params_ref const & p);
static void collect_param_descrs(param_descrs & d);
void free_memory();
void collect_statistics(statistics & st);
void reset_statistics();
};
};
#endif