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yap-6.3/packages/bee/cryptominisat-2.5.1/Solver/Gaussian.h
Vitor Santos Costa 16015bd8e6 bee
2019-04-22 12:15:21 +01:00

238 lines
9.2 KiB
C++
Executable File

/***********************************************************************************
CryptoMiniSat -- Copyright (c) 2009 Mate Soos
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
**************************************************************************************************/
#ifndef GAUSSIAN_H
#define GAUSSIAN_H
#include <vector>
#include <string>
#include <limits>
#ifdef _MSC_VER
#include <msvc/stdint.h>
#else
#include <stdint.h>
#endif //_MSC_VER
#include "SolverTypes.h"
#include "Solver.h"
#include "GaussianConfig.h"
#include "PackedMatrix.h"
#include "BitArray.h"
#ifdef VERBOSE_DEBUG
using std::vector;
using std::cout;
using std::endl;
#endif
using std::pair;
using std::string;
class Clause;
class Gaussian
{
public:
Gaussian(Solver& solver, const GaussianConfig& config, const uint matrix_no, const vector<XorClause*>& xorclauses);
~Gaussian();
const bool full_init();
llbool find_truths(vec<Lit>& learnt_clause, int& conflictC);
//statistics
void print_stats() const;
void print_matrix_stats() const;
const uint get_called() const;
const uint get_useful_prop() const;
const uint get_useful_confl() const;
const bool get_disabled() const;
const uint32_t get_unit_truths() const;
void set_disabled(const bool toset);
//functions used throughout the Solver
void canceling(const uint sublevel);
protected:
Solver& solver;
//Gauss high-level configuration
const GaussianConfig& config;
const uint matrix_no;
vector<XorClause*> xorclauses;
enum gaussian_ret {conflict, unit_conflict, propagation, unit_propagation, nothing};
gaussian_ret gaussian(Clause*& confl);
vector<Var> col_to_var_original; //Matches columns to variables
BitArray var_is_in; //variable is part of the the matrix. var_is_in's size is _minimal_ so you should check whether var_is_in.getSize() < var before issuing var_is_in[var]
uint badlevel;
class matrixset
{
public:
PackedMatrix matrix; // The matrix, updated to reflect variable assignements
BitArray var_is_set;
vector<Var> col_to_var; // col_to_var[COL] tells which variable is at a given column in the matrix. Gives unassigned_var if the COL has been zeroed (i.e. the variable assigned)
uint16_t num_rows; // number of active rows in the matrix. Unactive rows are rows that contain only zeros (and if they are conflicting, then the conflict has been treated)
uint num_cols; // number of active columns in the matrix. The columns at the end that have all be zeroed are no longer active
int least_column_changed; // when updating the matrix, this value contains the smallest column number that has been updated (Gauss elim. can start from here instead of from column 0)
vector<uint16_t> last_one_in_col; //last_one_in_col[COL] tells the last row+1 that has a '1' in that column. Used to reduce the burden of Gauss elim. (it only needs to look until that row)
vector<uint16_t> first_one_in_row;
uint removeable_cols; // the number of columns that have been zeroed out (i.e. assigned)
};
//Saved states
vector<matrixset> matrix_sets; // The matrixsets for depths 'decision_from' + 0, 'decision_from' + only_nth_gaussian_save, 'decision_from' + 2*only_nth_gaussian_save, ... 'decision_from' + 'decision_until'.
matrixset cur_matrixset; // The current matrixset, i.e. the one we are working on, or the last one we worked on
//Varibales to keep Gauss state
bool messed_matrix_vars_since_reversal;
int gauss_last_level;
vector<pair<Clause*, uint> > clauses_toclear;
bool disabled; // Gauss is disabled
//State of current elimnation
vec<uint> propagatable_rows; //used to store which rows were deemed propagatable during elimination
vector<unsigned char> changed_rows; //used to store which rows were deemed propagatable during elimination
//Statistics
uint useful_prop; //how many times Gauss gave propagation as a result
uint useful_confl; //how many times Gauss gave conflict as a result
uint called; //how many times called the Gauss
uint32_t unit_truths; //how many unitary (i.e. decisionLevel 0) truths have been found
//gauss init functions
void init(); // Initalise gauss state
void fill_matrix(matrixset& origMat); // Fills the origMat matrix
uint select_columnorder(vector<uint16_t>& var_to_col, matrixset& origMat); // Fills var_to_col and col_to_var of the origMat matrix.
//Main function
uint eliminate(matrixset& matrix, uint& conflict_row); //does the actual gaussian elimination
//matrix update functions
void update_matrix_col(matrixset& matrix, const Var x, const uint col); // Update one matrix column
void update_matrix_by_col_all(matrixset& m); // Update all columns, column-by-column (and not row-by-row)
void set_matrixset_to_cur(); // Save the current matrixset, the cur_matrixset to matrix_sets
//void update_matrix_by_row(matrixset& matrix) const;
//void update_matrix_by_col(matrixset& matrix, const uint last_level) const;
//conflict&propagation handling
gaussian_ret handle_matrix_prop_and_confl(matrixset& m, uint row, Clause*& confl);
void analyse_confl(const matrixset& m, const uint row, int32_t& maxlevel, uint& size, uint& best_row) const; // analyse conflcit to find the best conflict. Gets & returns the best one in 'maxlevel', 'size' and 'best row' (these are all UINT_MAX when calling this function first, i.e. when there is no other possible conflict to compare to the new in 'row')
gaussian_ret handle_matrix_confl(Clause*& confl, const matrixset& m, const uint size, const uint maxlevel, const uint best_row);
gaussian_ret handle_matrix_prop(matrixset& m, const uint row); // Handle matrix propagation at row 'row'
vec<Lit> tmp_clause;
//propagation&conflict handling
void cancel_until_sublevel(const uint until_sublevel); // cancels until sublevel 'until_sublevel'. The var 'until_sublevel' must NOT go over the current level. I.e. this function is ONLY for moving inside the current level
uint find_sublevel(const Var v) const; // find the sublevel (i.e. trail[X]) of a given variable
//helper functions
bool at_first_init() const;
bool should_init() const;
bool should_check_gauss(const uint decisionlevel, const uint starts) const;
void disable_if_necessary();
void reset_stats();
void update_last_one_in_col(matrixset& m);
private:
//debug functions
bool check_no_conflict(matrixset& m) const; // Are there any conflicts that the matrixset 'm' causes?
const bool nothing_to_propagate(matrixset& m) const; // Are there any conflicts of propagations that matrixset 'm' clauses?
template<class T>
void print_matrix_row(const T& row) const; // Print matrix row 'row'
template<class T>
void print_matrix_row_with_assigns(const T& row) const;
void check_matrix_against_varset(PackedMatrix& matrix,const matrixset& m) const;
const bool check_last_one_in_cols(matrixset& m) const;
const void check_first_one_in_row(matrixset& m, const uint j);
void print_matrix(matrixset& m) const;
void print_last_one_in_cols(matrixset& m) const;
static const string lbool_to_string(const lbool toprint);
};
inline bool Gaussian::should_init() const
{
return (config.decision_until > 0);
}
inline bool Gaussian::should_check_gauss(const uint decisionlevel, const uint starts) const
{
return (!disabled
&& decisionlevel < config.decision_until);
}
inline void Gaussian::canceling(const uint sublevel)
{
if (disabled)
return;
uint a = 0;
for (int i = clauses_toclear.size()-1; i >= 0 && clauses_toclear[i].second > sublevel; i--) {
clauseFree(clauses_toclear[i].first);
a++;
}
clauses_toclear.resize(clauses_toclear.size()-a);
if (messed_matrix_vars_since_reversal)
return;
int c = std::min((int)gauss_last_level, (int)(solver.trail.size())-1);
for (; c >= (int)sublevel; c--) {
Var var = solver.trail[c].var();
if (var < var_is_in.getSize()
&& var_is_in[var]
&& cur_matrixset.var_is_set[var]) {
messed_matrix_vars_since_reversal = true;
return;
}
}
}
inline const uint32_t Gaussian::get_unit_truths() const
{
return unit_truths;
}
inline const uint Gaussian::get_called() const
{
return called;
}
inline const uint Gaussian::get_useful_prop() const
{
return useful_prop;
}
inline const uint Gaussian::get_useful_confl() const
{
return useful_confl;
}
inline const bool Gaussian::get_disabled() const
{
return disabled;
}
inline void Gaussian::set_disabled(const bool toset)
{
disabled = toset;
}
std::ostream& operator << (std::ostream& os, const vec<Lit>& v);
#endif //GAUSSIAN_H