/*
* Full solver:
* - params: heuristic parameters.
* If params is NULL, the default settings are used.
* - verbose: if true, prints some data after each outer restart
*/
static void sat_solve(smt_core_t *core, core_param_t *params, bool verbose) {
uint32_t c_threshold, d_threshold; // Picosat-style
uint32_t reduce_threshold;
assert(smt_status(core) == STATUS_IDLE);
if (params == NULL) {
params = &default_settings;
}
set_randomness(core, params->randomness);
set_var_decay_factor(core, params->var_decay);
set_clause_decay_factor(core, params->clause_decay);
c_threshold = params->c_threshold;
d_threshold = params->d_threshold;
reduce_threshold = (uint32_t) (num_prob_clauses(core) * params->r_fraction);
if (reduce_threshold < params->r_threshold) {
reduce_threshold = params->r_threshold;
}
// initialize then do a propagation + simplification step.
start_search(core);
smt_process(core);
if (verbose) {
show_progress(core, d_threshold, reduce_threshold, true);
}
if (smt_status(core) == STATUS_SEARCHING) {
// loop
for (;;) {
sat_search(core, c_threshold, &reduce_threshold, params->r_factor);
if (smt_status(core) != STATUS_SEARCHING) break;
smt_restart(core);
// inner restart: increase c_threshold
c_threshold = (uint32_t) (c_threshold * params->c_factor);
if (c_threshold >= d_threshold) {
d_threshold = c_threshold;
if (params->fast_restart) {
// outer restart: reset c_threshold and increase d_threshold
c_threshold = params->c_threshold;
d_threshold = (uint32_t) (d_threshold * params->d_factor);
}
if (verbose) {
show_progress(core, d_threshold, reduce_threshold, false);
}
}
}
}
if (verbose) {
printf("---------------------------------------------------------------------------------\n\n");
fflush(stdout);
}
}
/*
* Full header: includes the learned clauses
*/
static void dimacs_print_full_header(FILE *f, smt_core_t *core) {
uint32_t num_clauses;
num_clauses = num_empty_clauses(core) + num_unit_clauses(core) + num_binary_clauses(core) +
num_prob_clauses(core) + num_learned_clauses(core) + 1;
fprintf(f, "p cnf %"PRIu32" %"PRIu32"\n", core->nvars, num_clauses);
}
/*
* Name and size of the problem + core settings
* and construction_time
*/
static void print_problem_size(FILE *f, smt_core_t *core, char *filename, double construction_time) {
fprintf(f, "Problem: %s\n\n", basename(filename));
fprintf(f, "Construction time : %.4f s\n", construction_time);
fprintf(f, "nb. of vars : %"PRIu32"\n", num_vars(core));
fprintf(f, "nb. of unit clauses : %"PRIu32"\n", num_unit_clauses(core));
fprintf(f, "nb. of bin clauses : %"PRIu32"\n", num_binary_clauses(core));
fprintf(f, "nb. of big clauses : %"PRIu32"\n", num_prob_clauses(core));
fprintf(f, "clause decay : %g\n", clause_decay_factor(core));
fprintf(f, "var decay : %g\n", var_decay_factor(core));
fprintf(f, "randomness factor : %g\n\n", randomness_factor(core));
}
/*
* Print some statistic data + header if requested (on stdout)
*/
static void show_progress(smt_core_t *core,
uint32_t restart_threshold, uint32_t reduce_threshold, bool show_header) {
if (show_header) {
printf("---------------------------------------------------------------------------------\n");
printf("| Thresholds | Binary | Original | Learned |\n");
printf("| Conf. Del. | Clauses | Clauses Lits. | Clauses Lits. Lits/Cl. |\n");
printf("---------------------------------------------------------------------------------\n");
}
printf("| %7"PRIu32" %8"PRIu32" | %8"PRIu32" | %8"PRIu32" %8"PRIu64" | %8"PRIu32" %8"PRIu64" %7.1f |\n",
restart_threshold, reduce_threshold,
num_binary_clauses(core),
num_prob_clauses(core), num_prob_literals(core),
num_learned_clauses(core), num_learned_literals(core),
((double) num_learned_literals(core)/num_learned_clauses(core)));
fflush(stdout);
}