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z3-z3-4.12.6.src.ast.sls.sls_tracker.h Maven / Gradle / Ivy
/*++
Copyright (c) 2012 Microsoft Corporation
Module Name:
sls_score_tracker.h
Abstract:
Score and value tracking module for SLS
Author:
Christoph (cwinter) 2012-02-29
Notes:
--*/
#pragma once
#include
#include "ast/for_each_expr.h"
#include "ast/ast_smt2_pp.h"
#include "ast/bv_decl_plugin.h"
#include "model/model.h"
#include "params/sls_params.hpp"
#include "ast/sls/sls_powers.h"
class sls_tracker {
ast_manager & m_manager;
unsynch_mpz_manager & m_mpz_manager;
bv_util & m_bv_util;
powers & m_powers;
random_gen m_rng;
unsigned m_random_bits;
unsigned m_random_bits_cnt;
mpz m_zero, m_one, m_two;
struct value_score {
value_score() : m(nullptr), value(unsynch_mpz_manager::mk_z(0)), score(0.0), score_prune(0.0), has_pos_occ(0), has_neg_occ(0), distance(0), touched(1) {};
value_score(value_score&&) noexcept = default;
~value_score() { if (m) m->del(value); }
value_score& operator=(value_score&&) = default;
unsynch_mpz_manager * m;
mpz value;
double score;
double score_prune;
unsigned has_pos_occ;
unsigned has_neg_occ;
unsigned distance; // max distance from any root
unsigned touched;
};
public:
typedef obj_map entry_point_type;
private:
typedef obj_map scores_type;
typedef obj_map > uplinks_type;
typedef obj_map > occ_type;
obj_hashtable m_top_expr;
scores_type m_scores;
uplinks_type m_uplinks;
entry_point_type m_entry_points;
ptr_vector m_constants;
ptr_vector m_temp_constants;
occ_type m_constants_occ;
unsigned m_last_pos;
unsigned m_walksat;
unsigned m_ucb;
double m_ucb_constant;
unsigned m_ucb_init;
double m_ucb_forget;
double m_ucb_noise;
unsigned m_touched;
double m_scale_unsat;
unsigned m_paws_init;
obj_map m_where_false;
expr** m_list_false;
unsigned m_track_unsat;
obj_map m_weights;
double m_top_sum;
obj_hashtable m_temp_seen;
public:
sls_tracker(ast_manager & m, bv_util & bvu, unsynch_mpz_manager & mm, powers & p) :
m_manager(m),
m_mpz_manager(mm),
m_bv_util(bvu),
m_powers(p),
m_random_bits_cnt(0),
m_zero(m_mpz_manager.mk_z(0)),
m_one(m_mpz_manager.mk_z(1)),
m_two(m_mpz_manager.mk_z(2)) {
}
~sls_tracker() {
m_mpz_manager.del(m_zero);
m_mpz_manager.del(m_one);
m_mpz_manager.del(m_two);
}
void updt_params(params_ref const & _p) {
sls_params p(_p);
m_walksat = p.walksat();
m_ucb = p.walksat_ucb();
m_ucb_constant = p.walksat_ucb_constant();
m_ucb_init = p.walksat_ucb_init();
m_ucb_forget = p.walksat_ucb_forget();
m_ucb_noise = p.walksat_ucb_noise();
m_scale_unsat = p.scale_unsat();
m_paws_init = p.paws_init();
// Andreas: track_unsat is currently disabled because I cannot guarantee that it is not buggy.
// If you want to use it, you will also need to change comments in the assertion selection.
m_track_unsat = 0;//p.track_unsat();
}
/* Andreas: Tried to give some measure for the formula size by the following two methods but both are not used currently.
unsigned get_formula_size() {
return m_scores.size();
}
double get_avg_bw(goal_ref const & g) {
double sum = 0.0;
unsigned count = 0;
for (unsigned i = 0; i < g->size(); i++)
{
m_temp_constants.reset();
ptr_vector const & this_decls = m_constants_occ.find(g->form(i));
unsigned sz = this_decls.size();
for (unsigned i = 0; i < sz; i++) {
func_decl * fd = this_decls[i];
m_temp_constants.push_back(fd);
sort * srt = fd->get_range();
sum += (m_manager.is_bool(srt)) ? 1 : m_bv_util.get_bv_size(srt);
count++;
}
}
return sum / count;
}*/
inline void adapt_top_sum(expr * e, double add, double sub) {
m_top_sum += m_weights.find(e) * (add - sub);
}
inline void set_top_sum(double new_score) {
m_top_sum = new_score;
}
inline double get_top_sum() {
return m_top_sum;
}
inline obj_hashtable const & get_top_exprs() {
return m_top_expr;
}
inline bool is_sat() {
for (obj_hashtable::iterator it = m_top_expr.begin();
it != m_top_expr.end();
it++)
if (!m_mpz_manager.is_one(get_value(*it)))
return false;
return true;
}
inline void set_value(expr * n, const mpz & r) {
SASSERT(m_scores.contains(n));
m_mpz_manager.set(m_scores.find(n).value, r);
}
inline void set_value(func_decl * fd, const mpz & r) {
SASSERT(m_entry_points.contains(fd));
expr * ep = get_entry_point(fd);
set_value(ep, r);
}
inline mpz & get_value(expr * n) {
SASSERT(m_scores.contains(n));
return m_scores.find(n).value;
}
inline mpz & get_value(func_decl * fd) {
SASSERT(m_entry_points.contains(fd));
expr * ep = get_entry_point(fd);
return get_value(ep);
}
inline void set_score(expr * n, double score) {
SASSERT(m_scores.contains(n));
m_scores.find(n).score = score;
}
inline void set_score(func_decl * fd, double score) {
SASSERT(m_entry_points.contains(fd));
expr * ep = get_entry_point(fd);
set_score(ep, score);
}
inline double & get_score(expr * n) {
SASSERT(m_scores.contains(n));
return m_scores.find(n).score;
}
inline double & get_score(func_decl * fd) {
SASSERT(m_entry_points.contains(fd));
expr * ep = get_entry_point(fd);
return get_score(ep);
}
inline void set_score_prune(expr * n, double score) {
SASSERT(m_scores.contains(n));
m_scores.find(n).score_prune = score;
}
inline double & get_score_prune(expr * n) {
SASSERT(m_scores.contains(n));
return m_scores.find(n).score_prune;
}
inline unsigned has_pos_occ(expr * n) {
SASSERT(m_scores.contains(n));
return m_scores.find(n).has_pos_occ;
}
inline unsigned has_neg_occ(expr * n) {
SASSERT(m_scores.contains(n));
return m_scores.find(n).has_neg_occ;
}
inline unsigned get_distance(expr * n) {
SASSERT(m_scores.contains(n));
return m_scores.find(n).distance;
}
inline void set_distance(expr * n, unsigned d) {
SASSERT(m_scores.contains(n));
m_scores.find(n).distance = d;
}
inline expr * get_entry_point(func_decl * fd) {
SASSERT(m_entry_points.contains(fd));
return m_entry_points.find(fd);
}
inline entry_point_type const & get_entry_points() {
return m_entry_points;
}
inline bool has_uplinks(expr * n) {
return m_uplinks.contains(n);
}
inline bool is_top_expr(expr * n) {
return m_top_expr.contains(n);
}
inline ptr_vector & get_uplinks(expr * n) {
SASSERT(m_uplinks.contains(n));
return m_uplinks.find(n);
}
inline void ucb_forget(ptr_vector & as) {
if (m_ucb_forget < 1.0)
{
expr * e;
unsigned touched_old, touched_new;
for (unsigned i = 0; i < as.size(); i++)
{
e = as[i];
touched_old = m_scores.find(e).touched;
touched_new = (unsigned)((touched_old - 1) * m_ucb_forget + 1);
m_scores.find(e).touched = touched_new;
m_touched += touched_new - touched_old;
}
}
}
void initialize(app * n) {
// Build score table
if (!m_scores.contains(n)) {
value_score vs;
vs.m = & m_mpz_manager;
m_scores.insert(n, std::move(vs));
}
// Update uplinks
unsigned na = n->get_num_args();
for (unsigned i = 0; i < na; i++) {
expr * c = n->get_arg(i);
m_uplinks.insert_if_not_there(c, ptr_vector()).push_back(n);
}
func_decl * d = n->get_decl();
if (n->get_num_args() == 0) {
if (d->get_family_id() != null_family_id) {
// Interpreted constant
mpz t;
value2mpz(n, t);
set_value(n, t);
m_mpz_manager.del(t);
}
else {
// Uninterpreted constant
m_entry_points.insert_if_not_there(d, n);
m_constants.push_back(d);
}
}
}
struct init_proc {
ast_manager & m_manager;
sls_tracker & m_tracker;
init_proc(ast_manager & m, sls_tracker & tracker):
m_manager(m),
m_tracker(tracker) {
}
void operator()(var * n) {}
void operator()(quantifier * n) {}
void operator()(app * n) {
m_tracker.initialize(n);
}
};
struct find_func_decls_proc {
ast_manager & m_manager;
ptr_vector & m_occs;
find_func_decls_proc (ast_manager & m, ptr_vector & occs):
m_manager(m),
m_occs(occs) {
}
void operator()(var * n) {}
void operator()(quantifier * n) {}
void operator()(app * n) {
if (n->get_num_args() != 0)
return;
func_decl * d = n->get_decl();
if (d->get_family_id() != null_family_id)
return;
m_occs.push_back(d);
}
};
void calculate_expr_distances(ptr_vector const & as) {
// precondition: m_scores is set up.
unsigned sz = as.size();
ptr_vector stack;
for (unsigned i = 0; i < sz; i++)
stack.push_back(to_app(as[i]));
while (!stack.empty()) {
app * cur = stack.back();
stack.pop_back();
unsigned d = get_distance(cur);
for (unsigned i = 0; i < cur->get_num_args(); i++) {
app * child = to_app(cur->get_arg(i));
unsigned d_child = get_distance(child);
if (d >= d_child) {
set_distance(child, d+1);
stack.push_back(child);
}
}
}
}
/* Andreas: Used this at some point to have values for the non-top-level expressions.
However, it did not give better performance but even cause some additional m/o - is not used currently.
void initialize_recursive(init_proc proc, expr_mark visited, expr * e) {
if (m_manager.is_and(e) || m_manager.is_or(e)) {
app * a = to_app(e);
expr * const * args = a->get_args();
unsigned int sz = a->get_num_args();
for (unsigned int i = 0; i < sz; i++) {
expr * q = args[i];
initialize_recursive(proc, visited, q);
}
}
for_each_expr(proc, visited, e);
}
void initialize_recursive(expr * e) {
if (m_manager.is_and(e) || m_manager.is_or(e)) {
app * a = to_app(e);
expr * const * args = a->get_args();
unsigned int sz = a->get_num_args();
for (unsigned int i = 0; i < sz; i++) {
expr * q = args[i];
initialize_recursive(q);
}
}
ptr_vector t;
m_constants_occ.insert_if_not_there(e, t);
find_func_decls_proc ffd_proc(m_manager, m_constants_occ.find(e));
expr_fast_mark1 visited;
quick_for_each_expr(ffd_proc, visited, e);
}*/
void initialize(ptr_vector const & as) {
init_proc proc(m_manager, *this);
expr_mark visited;
unsigned sz = as.size();
for (unsigned i = 0; i < sz; i++) {
expr * e = as[i];
if (!m_top_expr.contains(e))
m_top_expr.insert(e);
for_each_expr(proc, visited, e);
}
visited.reset();
for (unsigned i = 0; i < sz; i++) {
expr * e = as[i];
ptr_vector t;
m_constants_occ.insert_if_not_there(e, t);
find_func_decls_proc ffd_proc(m_manager, m_constants_occ.find(e));
expr_fast_mark1 visited;
quick_for_each_expr(ffd_proc, visited, e);
}
calculate_expr_distances(as);
TRACE("sls", tout << "Initial model:" << std::endl; show_model(tout); );
if (m_track_unsat)
{
m_list_false = new expr*[sz];
for (unsigned i = 0; i < sz; i++)
{
if (m_mpz_manager.eq(get_value(as[i]), m_zero))
break_assertion(as[i]);
}
}
m_temp_seen.reset();
for (unsigned i = 0; i < sz; i++)
{
expr * e = as[i];
// initialize weights
if (!m_weights.contains(e))
m_weights.insert(e, m_paws_init);
// positive/negative occurrences used for early pruning
setup_occs(as[i]);
}
// initialize ucb total touched value (individual ones are always initialized to 1)
m_touched = m_ucb_init ? as.size() : 1;
}
void increase_weight(expr * e)
{
m_weights.find(e)++;
}
void decrease_weight(expr * e)
{
unsigned old_weight = m_weights.find(e);
m_weights.find(e) = old_weight > m_paws_init ? old_weight - 1 : m_paws_init;
}
unsigned get_weight(expr * e)
{
return m_weights.find(e);
}
void make_assertion(expr * e)
{
if (m_track_unsat)
{
if (m_where_false.contains(e))
{
unsigned pos = m_where_false.find(e);
m_where_false.erase(e);
if (pos != m_where_false.size())
{
expr * q = m_list_false[m_where_false.size()];
m_list_false[pos] = q;
m_where_false.find(q) = pos;
}
}
}
}
void break_assertion(expr * e)
{
if (m_track_unsat)
{
if (!m_where_false.contains(e))
{
unsigned pos = m_where_false.size();
m_list_false[pos] = e;
m_where_false.insert(e, pos);
}
}
}
void show_model(std::ostream & out) {
unsigned sz = get_num_constants();
for (unsigned i = 0; i < sz; i++) {
func_decl * fd = get_constant(i);
out << fd->get_name() << " = " << m_mpz_manager.to_string(get_value(fd)) << std::endl;
}
}
void set_model(model_ref const & mdl) {
for (unsigned i = 0; i < mdl->get_num_constants(); i++) {
func_decl * fd = mdl->get_constant(i);
expr * val = mdl->get_const_interp(fd);
if (m_entry_points.contains(fd)) {
if (m_manager.is_bool(val)) {
set_value(fd, m_manager.is_true(val) ? m_mpz_manager.mk_z(1) : m_mpz_manager.mk_z(0));
}
else if (m_bv_util.is_numeral(val)) {
rational r_val;
unsigned bv_sz;
m_bv_util.is_numeral(val, r_val, bv_sz);
const mpq& q = r_val.to_mpq();
SASSERT(m_mpz_manager.is_one(q.denominator()));
set_value(fd, q.numerator());
}
else
NOT_IMPLEMENTED_YET();
}
}
}
model_ref get_model() {
model_ref res = alloc(model, m_manager);
unsigned sz = get_num_constants();
for (unsigned i = 0; i < sz; i++) {
func_decl * fd = get_constant(i);
res->register_decl(fd, mpz2value(fd->get_range(), get_value(fd)));
}
return res;
}
unsigned get_num_constants() {
return m_constants.size();
}
ptr_vector & get_constants() {
return m_constants;
}
func_decl * get_constant(unsigned i) {
return m_constants[i];
}
void set_random_seed(unsigned s) {
m_rng.set_seed(s);
}
mpz get_random_bv(sort * s) {
SASSERT(m_bv_util.is_bv_sort(s));
unsigned bv_size = m_bv_util.get_bv_size(s);
mpz r; m_mpz_manager.set(r, 0);
mpz temp;
do
{
m_mpz_manager.mul(r, m_two, temp);
m_mpz_manager.add(temp, get_random_bool(), r);
} while (--bv_size > 0);
m_mpz_manager.del(temp);
return r;
}
mpz & get_random_bool() {
if (m_random_bits_cnt == 0) {
m_random_bits = m_rng();
m_random_bits_cnt = 15; // random_gen produces 15 bits of randomness.
}
bool val = (m_random_bits & 0x01) != 0;
m_random_bits = m_random_bits >> 1;
m_random_bits_cnt--;
return (val) ? m_one : m_zero;
}
unsigned get_random_uint(unsigned bits) {
if (m_random_bits_cnt == 0) {
m_random_bits = m_rng();
m_random_bits_cnt = 15; // random_gen produces 15 bits of randomness.
}
unsigned val = 0;
while (bits-- > 0) {
if ((m_random_bits & 0x01) != 0) val++;
val <<= 1;
m_random_bits >>= 1;
m_random_bits_cnt--;
if (m_random_bits_cnt == 0) {
m_random_bits = m_rng();
m_random_bits_cnt = 15; // random_gen produces 15 bits of randomness.
}
}
return val;
}
mpz get_random(sort * s) {
if (m_bv_util.is_bv_sort(s))
return get_random_bv(s);
else if (m_manager.is_bool(s))
return m_mpz_manager.dup(get_random_bool());
else {
NOT_IMPLEMENTED_YET(); // This only works for bit-vectors for now.
return get_random_bv(nullptr);
}
}
void randomize(ptr_vector const & as) {
TRACE("sls", tout << "Abandoned model:" << std::endl; show_model(tout); );
for (entry_point_type::iterator it = m_entry_points.begin(); it != m_entry_points.end(); it++) {
func_decl * fd = it->m_key;
sort * s = fd->get_range();
mpz temp = get_random(s);
set_value(it->m_value, temp);
m_mpz_manager.del(temp);
}
TRACE("sls", tout << "Randomized model:" << std::endl; show_model(tout); );
}
void reset(ptr_vector const & as) {
TRACE("sls", tout << "Abandoned model:" << std::endl; show_model(tout); );
for (entry_point_type::iterator it = m_entry_points.begin(); it != m_entry_points.end(); it++) {
set_value(it->m_value, m_zero);
}
}
void setup_occs(expr * n, bool negated = false) {
if (m_manager.is_bool(n))
{
if (m_manager.is_and(n) || m_manager.is_or(n))
{
SASSERT(!negated);
app * a = to_app(n);
expr * const * args = a->get_args();
for (unsigned i = 0; i < a->get_num_args(); i++)
{
expr * child = args[i];
if (!m_temp_seen.contains(child))
{
setup_occs(child, false);
m_temp_seen.insert(child);
}
}
}
else if (m_manager.is_not(n))
{
SASSERT(!negated);
app * a = to_app(n);
SASSERT(a->get_num_args() == 1);
expr * child = a->get_arg(0);
SASSERT(!m_manager.is_and(child) && !m_manager.is_or(child));
setup_occs(child, true);
}
else
{
if (negated)
m_scores.find(n).has_neg_occ = 1;
else
m_scores.find(n).has_pos_occ = 1;
}
}
else if (m_bv_util.is_bv(n)) {
/* CMW: I need this for optimization. Safe to ignore? */
}
else
NOT_IMPLEMENTED_YET();
}
double score_bool(expr * n, bool negated = false) {
TRACE("sls_score", tout << ((negated)?"NEG ":"") << "BOOL: " << mk_ismt2_pp(n, m_manager) << std::endl; );
double res = 0.0;
if (is_uninterp_const(n)) {
const mpz & r = get_value(n);
if (negated)
res = (m_mpz_manager.is_one(r)) ? 0.0 : 1.0;
else
res = (m_mpz_manager.is_one(r)) ? 1.0 : 0.0;
}
else if (m_manager.is_and(n)) {
SASSERT(!negated);
app * a = to_app(n);
expr * const * args = a->get_args();
/* Andreas: Seems to have no effect. But maybe you want to try it again at some point.
double sum = 0.0;
for (unsigned i = 0; i < a->get_num_args(); i++)
sum += get_score(args[i]);
res = sum / (double) a->get_num_args(); */
double min = 1.0;
for (unsigned i = 0; i < a->get_num_args(); i++) {
double cur = get_score(args[i]);
if (cur < min) min = cur;
}
res = min;
}
else if (m_manager.is_or(n)) {
SASSERT(!negated);
app * a = to_app(n);
expr * const * args = a->get_args();
double max = 0.0;
for (unsigned i = 0; i < a->get_num_args(); i++) {
double cur = get_score(args[i]);
if (cur > max) max = cur;
}
res = max;
}
else if (m_manager.is_ite(n)) {
SASSERT(!negated);
app * a = to_app(n);
SASSERT(a->get_num_args() == 3);
const mpz & cond = get_value(a->get_arg(0));
double s_t = get_score(a->get_arg(1));
double s_f = get_score(a->get_arg(2));
res = (m_mpz_manager.is_one(cond)) ? s_t : s_f;
}
else if (m_manager.is_eq(n) || m_manager.is_iff(n)) {
app * a = to_app(n);
SASSERT(a->get_num_args() == 2);
expr * arg0 = a->get_arg(0);
expr * arg1 = a->get_arg(1);
const mpz & v0 = get_value(arg0);
const mpz & v1 = get_value(arg1);
if (negated) {
res = (m_mpz_manager.eq(v0, v1)) ? 0.0 : 1.0;
TRACE("sls_score", tout << "V0 = " << m_mpz_manager.to_string(v0) << " ; V1 = " <<
m_mpz_manager.to_string(v1) << std::endl; );
}
else if (m_manager.is_bool(arg0)) {
res = m_mpz_manager.eq(v0, v1) ? 1.0 : 0.0;
TRACE("sls_score", tout << "V0 = " << m_mpz_manager.to_string(v0) << " ; V1 = " <<
m_mpz_manager.to_string(v1) << std::endl; );
}
else if (m_bv_util.is_bv(arg0)) {
mpz diff, diff_m1;
m_mpz_manager.bitwise_xor(v0, v1, diff);
unsigned hamming_distance = 0;
unsigned bv_sz = m_bv_util.get_bv_size(arg0);
// unweighted hamming distance
while (!m_mpz_manager.is_zero(diff)) {
if (!m_mpz_manager.is_even(diff)) {
hamming_distance++;
}
m_mpz_manager.machine_div(diff, m_two, diff);
}
res = 1.0 - (hamming_distance / (double) bv_sz);
TRACE("sls_score", tout << "V0 = " << m_mpz_manager.to_string(v0) << " ; V1 = " <<
m_mpz_manager.to_string(v1) << " ; HD = " << hamming_distance <<
" ; SZ = " << bv_sz << std::endl; );
m_mpz_manager.del(diff);
m_mpz_manager.del(diff_m1);
}
else
NOT_IMPLEMENTED_YET();
}
else if (m_bv_util.is_bv_ule(n)) { // x <= y
app * a = to_app(n);
SASSERT(a->get_num_args() == 2);
const mpz & x = get_value(a->get_arg(0));
const mpz & y = get_value(a->get_arg(1));
int bv_sz = m_bv_util.get_bv_size(a->get_decl()->get_domain()[0]);
if (negated) {
if (m_mpz_manager.gt(x, y))
res = 1.0;
else {
mpz diff;
m_mpz_manager.sub(y, x, diff);
m_mpz_manager.inc(diff);
rational n(diff);
n /= rational(m_powers(bv_sz));
double dbl = n.get_double();
// In extreme cases, n is 0.9999 but to_double returns something > 1.0
res = (dbl > 1.0) ? 0.0 : (dbl < 0.0) ? 1.0 : 1.0 - dbl;
m_mpz_manager.del(diff);
}
}
else {
if (m_mpz_manager.le(x, y))
res = 1.0;
else {
mpz diff;
m_mpz_manager.sub(x, y, diff);
rational n(diff);
n /= rational(m_powers(bv_sz));
double dbl = n.get_double();
res = (dbl > 1.0) ? 0.0 : (dbl < 0.0) ? 1.0 : 1.0 - dbl;
m_mpz_manager.del(diff);
}
}
TRACE("sls_score", tout << "x = " << m_mpz_manager.to_string(x) << " ; y = " <<
m_mpz_manager.to_string(y) << " ; SZ = " << bv_sz << std::endl; );
}
else if (m_bv_util.is_bv_sle(n)) { // x <= y
app * a = to_app(n);
SASSERT(a->get_num_args() == 2);
mpz x; m_mpz_manager.set(x, get_value(a->get_arg(0)));
mpz y; m_mpz_manager.set(y, get_value(a->get_arg(1)));
unsigned bv_sz = m_bv_util.get_bv_size(a->get_decl()->get_domain()[0]);
const mpz & p = m_powers(bv_sz);
const mpz & p_half = m_powers(bv_sz-1);
if (x >= p_half) { m_mpz_manager.sub(x, p, x); }
if (y >= p_half) { m_mpz_manager.sub(y, p, y); }
if (negated) {
if (x > y)
res = 1.0;
else {
mpz diff;
m_mpz_manager.sub(y, x, diff);
m_mpz_manager.inc(diff);
rational n(diff);
n /= p;
double dbl = n.get_double();
res = (dbl > 1.0) ? 0.0 : (dbl < 0.0) ? 1.0 : 1.0 - dbl;
m_mpz_manager.del(diff);
}
TRACE("sls_score", tout << "x = " << m_mpz_manager.to_string(x) << " ; y = " <<
m_mpz_manager.to_string(y) << " ; SZ = " << bv_sz << std::endl; );
}
else {
if (x <= y)
res = 1.0;
else {
mpz diff;
m_mpz_manager.sub(x, y, diff);
SASSERT(!m_mpz_manager.is_neg(diff));
rational n(diff);
n /= p;
double dbl = n.get_double();
res = (dbl > 1.0) ? 0.0 : (dbl < 0.0) ? 1.0 : 1.0 - dbl;
m_mpz_manager.del(diff);
}
TRACE("sls_score", tout << "x = " << m_mpz_manager.to_string(x) << " ; y = " <<
m_mpz_manager.to_string(y) << " ; SZ = " << bv_sz << std::endl; );
}
m_mpz_manager.del(x);
m_mpz_manager.del(y);
}
else if (m_manager.is_not(n)) {
SASSERT(!negated);
app * a = to_app(n);
SASSERT(a->get_num_args() == 1);
expr * child = a->get_arg(0);
// Precondition: Assertion set is in NNF.
// Also: careful about the unsat assertion scaling further down.
if (m_manager.is_and(child) || m_manager.is_or(child))
NOT_IMPLEMENTED_YET();
res = score_bool(child, true);
}
else if (m_manager.is_distinct(n)) {
app * a = to_app(n);
unsigned pairs = 0, distinct_pairs = 0;
unsigned sz = a->get_num_args();
for (unsigned i = 0; i < sz; i++) {
for (unsigned j = i+1; j < sz; j++) {
// pair i/j
const mpz & v0 = get_value(a->get_arg(0));
const mpz & v1 = get_value(a->get_arg(1));
pairs++;
if (v0 != v1)
distinct_pairs++;
}
}
res = (distinct_pairs/(double)pairs);
if (negated) res = 1.0 - res;
}
else
NOT_IMPLEMENTED_YET();
SASSERT(res >= 0.0 && res <= 1.0);
app * a = to_app(n);
family_id afid = a->get_family_id();
if (afid == m_bv_util.get_family_id())
if (res < 1.0) res *= m_scale_unsat;
TRACE("sls_score", tout << "SCORE = " << res << std::endl; );
return res;
}
double score_bv(expr * n) {
return 0.0; // a bv-expr is always scored as 0.0; we won't use those scores.
}
void value2mpz(expr * n, mpz & result) {
m_mpz_manager.set(result, m_zero);
if (m_manager.is_bool(n)) {
m_mpz_manager.set(result, m_manager.is_true(n) ? m_one : m_zero);
}
else if (m_bv_util.is_bv(n)) {
unsigned bv_sz = m_bv_util.get_bv_size(n);
rational q;
if (!m_bv_util.is_numeral(n, q, bv_sz))
NOT_IMPLEMENTED_YET();
const mpq& temp = q.to_mpq();
SASSERT(m_mpz_manager.is_one(temp.denominator()));
m_mpz_manager.set(result, temp.numerator());
}
else
NOT_IMPLEMENTED_YET();
}
expr_ref mpz2value(sort * s, const mpz & r) {
expr_ref res(m_manager);
if (m_manager.is_bool(s))
res = (m_mpz_manager.is_zero(r)) ? m_manager.mk_false() : m_manager.mk_true();
else if (m_bv_util.is_bv_sort(s)) {
rational rat(r);
res = m_bv_util.mk_numeral(rat, s);
}
else
NOT_IMPLEMENTED_YET();
return res;
}
double score(expr * n) {
if (m_manager.is_bool(n))
return score_bool(n);
else if (m_bv_util.is_bv(n))
return score_bv(n);
else {
NOT_IMPLEMENTED_YET();
return 0;
}
}
ptr_vector & get_constants(expr * e) {
ptr_vector const & this_decls = m_constants_occ.find(e);
unsigned sz = this_decls.size();
for (unsigned i = 0; i < sz; i++) {
func_decl * fd = this_decls[i];
if (!m_temp_constants.contains(fd))
m_temp_constants.push_back(fd);
}
return m_temp_constants;
}
ptr_vector & get_unsat_constants_gsat(ptr_vector const & as) {
unsigned sz = as.size();
if (sz == 1) {
if (m_mpz_manager.neq(get_value(as[0]), m_one))
return get_constants();
}
m_temp_constants.reset();
for (unsigned i = 0; i < sz; i++) {
expr * q = as[i];
if (m_mpz_manager.eq(get_value(q), m_one))
continue;
ptr_vector const & this_decls = m_constants_occ.find(q);
unsigned sz2 = this_decls.size();
for (unsigned j = 0; j < sz2; j++) {
func_decl * fd = this_decls[j];
if (!m_temp_constants.contains(fd))
m_temp_constants.push_back(fd);
}
}
return m_temp_constants;
}
ptr_vector & get_unsat_constants_walksat(expr * e) {
if (!e || !m_temp_constants.empty())
return m_temp_constants;
ptr_vector const & this_decls = m_constants_occ.find(e);
unsigned sz = this_decls.size();
for (unsigned j = 0; j < sz; j++) {
func_decl * fd = this_decls[j];
if (!m_temp_constants.contains(fd))
m_temp_constants.push_back(fd);
}
return m_temp_constants;
}
ptr_vector & get_unsat_constants(ptr_vector const & as) {
if (m_walksat)
{
expr * e = get_unsat_assertion(as);
if (!e)
{
m_temp_constants.reset();
return m_temp_constants;
}
return get_unsat_constants_walksat(e);
}
else
return get_unsat_constants_gsat(as);
}
expr * get_unsat_assertion(ptr_vector const & as) {
unsigned sz = as.size();
if (sz == 1) {
if (m_mpz_manager.neq(get_value(as[0]), m_one))
return as[0];
else
return nullptr;
}
m_temp_constants.reset();
unsigned pos = -1;
if (m_ucb)
{
double max = -1.0;
// Andreas: Commented things here might be used for track_unsat data structures as done in SLS for SAT. But seems to have no benefit.
/* for (unsigned i = 0; i < m_where_false.size(); i++) {
expr * e = m_list_false[i]; */
for (unsigned i = 0; i < sz; i++) {
expr * e = as[i];
if (m_mpz_manager.neq(get_value(e), m_one))
{
value_score & vscore = m_scores.find(e);
// Andreas: Select the assertion with the greatest ucb score. Potentially add some noise.
// double q = vscore.score + m_ucb_constant * sqrt(log((double)m_touched) / vscore.touched);
double q = vscore.score + m_ucb_constant * sqrt(log((double)m_touched) / vscore.touched) + m_ucb_noise * get_random_uint(8);
if (q > max) { max = q; pos = i; }
}
}
if (pos == static_cast(-1))
return nullptr;
m_touched++;
m_scores.find(as[pos]).touched++;
// Andreas: Also part of track_unsat data structures. Additionally disable the previous line!
/* m_last_pos = pos;
m_scores.find(m_list_false[pos]).touched++;
return m_list_false[pos]; */
}
else
{
// Andreas: The track_unsat data structures for random assertion selection.
/* sz = m_where_false.size();
if (sz == 0)
return 0;
return m_list_false[get_random_uint(16) % sz]; */
unsigned cnt_unsat = 0;
for (unsigned i = 0; i < sz; i++)
if (m_mpz_manager.neq(get_value(as[i]), m_one) && (get_random_uint(16) % ++cnt_unsat == 0)) pos = i;
if (pos == static_cast(-1))
return nullptr;
}
m_last_pos = pos;
return as[pos];
}
expr * get_new_unsat_assertion(ptr_vector const & as) {
unsigned sz = as.size();
if (sz == 1)
return nullptr;
m_temp_constants.reset();
unsigned cnt_unsat = 0, pos = -1;
for (unsigned i = 0; i < sz; i++)
if ((i != m_last_pos) && m_mpz_manager.neq(get_value(as[i]), m_one) && (get_random_uint(16) % ++cnt_unsat == 0)) pos = i;
if (pos == static_cast(-1))
return nullptr;
return as[pos];
}
};
