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

1914 lines
80 KiB
C++

/*++
Copyright (c) 2012 Microsoft Corporation
Module Name:
sls_tactic.h
Abstract:
A Stochastic Local Search (SLS) tactic
Author:
Christoph (cwinter) 2012-02-29
Notes:
--*/
#include<iomanip>
#include"map.h"
#include"nnf.h"
#include"cooperate.h"
#include"ast_smt2_pp.h"
#include"ast_pp.h"
#include"var_subst.h"
#include"model_pp.h"
#include"model_evaluator.h"
#include"solve_eqs_tactic.h"
#include"assertion_set_rewriter.h"
#include"shallow_context_simplifier.h"
#include"elim_uncnstr_tactic.h"
#include"bv_size_reduction_tactic.h"
#include"max_bv_sharing_tactic.h"
#include"simplify_tactic.h"
#include"stopwatch.h"
#include"expr2dot.h"
#include"propagate_values_tactic.h"
#include"sls_tactic.h"
class sls_tactic : public tactic {
class stats {
public:
unsigned m_restarts;
stopwatch m_stopwatch;
unsigned m_full_evals;
unsigned m_incr_evals;
unsigned m_moves, m_flips, m_incs, m_decs, m_invs;
stats() :
m_restarts(0),
m_full_evals(0),
m_incr_evals(0),
m_moves(0),
m_flips(0),
m_incs(0),
m_decs(0),
m_invs(0) {
m_stopwatch.reset();
m_stopwatch.start();
}
void reset() {
m_full_evals = m_flips = m_incr_evals = 0;
m_stopwatch.reset();
m_stopwatch.start();
}
};
struct imp {
class score_tracker;
class powers : public u_map<mpz*> {
unsynch_mpz_manager & m;
public:
powers(unsynch_mpz_manager & m) : m(m) {}
~powers() {
for (iterator it = begin(); it != end(); it++) {
m.del(*it->m_value);
dealloc(it->m_value);
}
}
const mpz & operator()(unsigned n) {
u_map<mpz*>::iterator it = find_iterator(n);
if (it != end())
return *it->m_value;
else {
mpz * new_obj = alloc(mpz);
insert(n, new_obj);
m.power(unsynch_mpz_manager::mk_z(2), n, *new_obj);
return *new_obj;
}
}
};
class evaluator {
ast_manager & m_manager;
bv_util & m_bv_util;
family_id m_bv_fid;
score_tracker & m_tracker;
unsynch_mpz_manager & m_mpz_manager;
mpz m_zero, m_one, m_two;
powers & m_powers;
public:
evaluator(ast_manager & m, bv_util & bvu, score_tracker & t, unsynch_mpz_manager & mm, powers & p) :
m_manager(m),
m_bv_util(bvu),
m_tracker(t),
m_mpz_manager(mm),
m_zero(m_mpz_manager.mk_z(0)),
m_one(m_mpz_manager.mk_z(1)),
m_two(m_mpz_manager.mk_z(2)),
m_powers(p) {
m_bv_fid = m_bv_util.get_family_id();
}
~evaluator() {
m_mpz_manager.del(m_zero);
m_mpz_manager.del(m_one);
m_mpz_manager.del(m_two);
}
void operator()(app * n, mpz & result) {
func_decl * fd = n->get_decl();
unsigned n_args = n->get_num_args();
expr * const * args = n->get_args();
m_mpz_manager.set(result, m_zero);
if (m_manager.is_and(n)) {
m_mpz_manager.set(result, m_one);
for (unsigned i = 0; i < n_args; i++) {
if (m_mpz_manager.neq(m_tracker.get_value(args[i]), result)) {
m_mpz_manager.set(result, m_zero);
break;
}
}
}
else if (m_manager.is_or(n)) {
for (unsigned i = 0; i < n_args; i++) {
if (m_mpz_manager.neq(m_tracker.get_value(args[i]), result)) {
m_mpz_manager.set(result, m_one);
break;
}
}
}
else if (m_manager.is_not(n)) {
SASSERT(n_args == 1);
const mpz & child = m_tracker.get_value(args[0]);
SASSERT(m_mpz_manager.is_one(child) || m_mpz_manager.is_zero(child));
m_mpz_manager.set(result, (m_mpz_manager.is_zero(child)) ? m_one : m_zero);
}
else if (m_manager.is_eq(n)) {
SASSERT(n_args >= 2);
m_mpz_manager.set(result, m_one);
const mpz & first = m_tracker.get_value(args[0]);
for (unsigned i = 1; i < n_args; i++) {
if (m_mpz_manager.neq(m_tracker.get_value(args[i]), first)) {
m_mpz_manager.set(result, m_zero);
break;
}
}
}
else if (m_manager.is_distinct(n)) {
m_mpz_manager.set(result, m_one);
for (unsigned i = 0; i < n_args && m_mpz_manager.is_one(result); i++) {
for (unsigned j = i+1; j < n_args && m_mpz_manager.is_one(result); j++) {
if (m_mpz_manager.eq(m_tracker.get_value(args[i]), m_tracker.get_value(args[j])))
m_mpz_manager.set(result, m_zero);
}
}
}
else if (fd->get_family_id() == m_bv_fid) {
bv_op_kind k = static_cast<bv_op_kind>(fd->get_decl_kind());
switch(k) {
case OP_CONCAT: {
SASSERT(n_args >= 2);
for (unsigned i = 0; i < n_args; i++) {
if (i != 0) {
const mpz & p = m_powers(m_bv_util.get_bv_size(args[i]));
m_mpz_manager.mul(result, p, result);
}
m_mpz_manager.add(result, m_tracker.get_value(args[i]), result);
}
break;
}
case OP_EXTRACT: {
SASSERT(n_args == 1);
const mpz & child = m_tracker.get_value(args[0]);
unsigned h = m_bv_util.get_extract_high(n);
unsigned l = m_bv_util.get_extract_low(n);
mpz mask;
m_mpz_manager.set(mask, m_powers(h+1));
m_mpz_manager.dec(mask);
m_mpz_manager.bitwise_and(child, mask, result); // result = [h:0] of child
// shift result by l
for (; l != 0 ; l--)
m_mpz_manager.machine_div(result, m_two, result);
m_mpz_manager.del(mask);
break;
}
case OP_BADD: {
SASSERT(n_args >= 2);
for (unsigned i = 0; i < n_args; i++) {
const mpz & next = m_tracker.get_value(args[i]);
m_mpz_manager.add(result, next, result);
}
const mpz & p = m_powers(m_bv_util.get_bv_size(n));
m_mpz_manager.rem(result, p, result);
break;
}
case OP_BSUB: {
SASSERT(n_args == 2);
const mpz & p = m_powers(m_bv_util.get_bv_size(n));
mpz temp;
m_mpz_manager.sub(m_tracker.get_value(args[0]), m_tracker.get_value(args[1]), temp);
m_mpz_manager.mod(temp, p, result);
m_mpz_manager.del(temp);
break;
}
case OP_BMUL: {
SASSERT(n_args >= 2);
m_mpz_manager.set(result, m_tracker.get_value(args[0]));
for (unsigned i = 1; i < n_args; i++) {
const mpz & next = m_tracker.get_value(args[i]);
m_mpz_manager.mul(result, next, result);
}
const mpz & p = m_powers(m_bv_util.get_bv_size(n));
m_mpz_manager.rem(result, p, result);
break;
}
case OP_BNEG: { // 2's complement unary minus
SASSERT(n_args == 1);
const mpz & child = m_tracker.get_value(args[0]);
if (m_mpz_manager.is_zero(child)) {
m_mpz_manager.set(result, m_zero);
}
else {
unsigned bv_sz = m_bv_util.get_bv_size(n);
m_mpz_manager.bitwise_not(bv_sz, child, result);
m_mpz_manager.inc(result); // can't overflow
}
break;
}
case OP_BSDIV:
case OP_BSDIV0:
case OP_BSDIV_I: {
SASSERT(n_args == 2);
mpz x; m_mpz_manager.set(x, m_tracker.get_value(args[0]));
mpz y; m_mpz_manager.set(y, m_tracker.get_value(args[1]));
SASSERT(m_mpz_manager.is_nonneg(x) && m_mpz_manager.is_nonneg(y));
unsigned bv_sz = m_bv_util.get_bv_size(args[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 (m_mpz_manager.is_zero(y)) {
if (m_mpz_manager.is_neg(x))
m_mpz_manager.set(result, m_one);
else {
m_mpz_manager.set(result, m_powers(m_bv_util.get_bv_size(n)));
m_mpz_manager.dec(result);
}
}
else {
m_mpz_manager.machine_div(x, y, result);
}
if (m_mpz_manager.is_neg(result))
m_mpz_manager.add(result, p, result);
m_mpz_manager.del(x);
m_mpz_manager.del(y);
break;
}
case OP_BUDIV:
case OP_BUDIV0:
case OP_BUDIV_I: {
SASSERT(n_args == 2);
mpz x; m_mpz_manager.set(x, m_tracker.get_value(args[0]));
mpz y; m_mpz_manager.set(y, m_tracker.get_value(args[1]));
if (m_mpz_manager.is_zero(y)) {
m_mpz_manager.set(result, m_powers(m_bv_util.get_bv_size(n)));
m_mpz_manager.dec(result);
}
else {
m_mpz_manager.machine_div(x, y, result);
}
m_mpz_manager.del(x);
m_mpz_manager.del(y);
break;
}
case OP_BSREM:
case OP_BSREM0:
case OP_BSREM_I: {
SASSERT(n_args == 2);
mpz x; m_mpz_manager.set(x, m_tracker.get_value(args[0]));
mpz y; m_mpz_manager.set(y, m_tracker.get_value(args[1]));
unsigned bv_sz = m_bv_util.get_bv_size(args[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 (m_mpz_manager.is_zero(y)) {
m_mpz_manager.set(result, x);
}
else {
m_mpz_manager.rem(x, y, result);
}
if (m_mpz_manager.is_neg(result))
m_mpz_manager.add(result, p, result);
m_mpz_manager.del(x);
m_mpz_manager.del(y);
break;
}
case OP_BUREM:
case OP_BUREM0:
case OP_BUREM_I: {
SASSERT(n_args == 2);
mpz x; m_mpz_manager.set(x, m_tracker.get_value(args[0]));
mpz y; m_mpz_manager.set(y, m_tracker.get_value(args[1]));
if (m_mpz_manager.is_zero(y)) {
m_mpz_manager.set(result, x);
}
else {
m_mpz_manager.mod(x, y, result);
}
m_mpz_manager.del(x);
m_mpz_manager.del(y);
break;
}
case OP_BSMOD:
case OP_BSMOD0:
case OP_BSMOD_I:{
SASSERT(n_args == 2);
mpz x; m_mpz_manager.set(x, m_tracker.get_value(args[0]));
mpz y; m_mpz_manager.set(y, m_tracker.get_value(args[1]));
unsigned bv_sz = m_bv_util.get_bv_size(args[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 (m_mpz_manager.is_zero(y))
m_mpz_manager.set(result, x);
else {
bool neg_x = m_mpz_manager.is_neg(x);
bool neg_y = m_mpz_manager.is_neg(y);
mpz abs_x, abs_y;
m_mpz_manager.set(abs_x, x);
m_mpz_manager.set(abs_y, y);
if (neg_x) m_mpz_manager.neg(abs_x);
if (neg_y) m_mpz_manager.neg(abs_y);
SASSERT(m_mpz_manager.is_nonneg(abs_x) && m_mpz_manager.is_nonneg(abs_y));
m_mpz_manager.mod(abs_x, abs_y, result);
if (m_mpz_manager.is_zero(result) || (!neg_x && !neg_y)) {
/* Nothing */
}
else if (neg_x && !neg_y) {
m_mpz_manager.neg(result);
m_mpz_manager.add(result, y, result);
}
else if (!neg_x && neg_y) {
m_mpz_manager.add(result, y, result);
}
else {
m_mpz_manager.neg(result);
}
m_mpz_manager.del(abs_x);
m_mpz_manager.del(abs_y);
}
if (m_mpz_manager.is_neg(result))
m_mpz_manager.add(result, p, result);
m_mpz_manager.del(x);
m_mpz_manager.del(y);
break;
}
case OP_BAND: {
SASSERT(n_args >= 2);
m_mpz_manager.set(result, m_tracker.get_value(args[0]));
for (unsigned i = 1; i < n_args; i++)
m_mpz_manager.bitwise_and(result, m_tracker.get_value(args[i]), result);
break;
}
case OP_BOR: {
SASSERT(n_args >= 2);
m_mpz_manager.set(result, m_tracker.get_value(args[0]));
for (unsigned i = 1; i < n_args; i++) {
m_mpz_manager.bitwise_or(result, m_tracker.get_value(args[i]), result);
}
break;
}
case OP_BXOR: {
SASSERT(n_args >= 2);
m_mpz_manager.set(result, m_tracker.get_value(args[0]));
for (unsigned i = 1; i < n_args; i++)
m_mpz_manager.bitwise_xor(result, m_tracker.get_value(args[i]), result);
break;
}
case OP_BNAND: {
SASSERT(n_args >= 2);
mpz temp;
unsigned bv_sz = m_bv_util.get_bv_size(n);
m_mpz_manager.set(result, m_tracker.get_value(args[0]));
for (unsigned i = 1; i < n_args; i++) {
m_mpz_manager.bitwise_and(result, m_tracker.get_value(args[i]), temp);
m_mpz_manager.bitwise_not(bv_sz, temp, result);
}
m_mpz_manager.del(temp);
break;
}
case OP_BNOR: {
SASSERT(n_args >= 2);
mpz temp;
unsigned bv_sz = m_bv_util.get_bv_size(n);
m_mpz_manager.set(result, m_tracker.get_value(args[0]));
for (unsigned i = 1; i < n_args; i++) {
m_mpz_manager.bitwise_or(result, m_tracker.get_value(args[i]), temp);
m_mpz_manager.bitwise_not(bv_sz, temp, result);
}
m_mpz_manager.del(temp);
break;
}
case OP_BNOT: {
SASSERT(n_args == 1);
m_mpz_manager.bitwise_not(m_bv_util.get_bv_size(args[0]), m_tracker.get_value(args[0]), result);
break;
}
case OP_ULT:
case OP_ULEQ:
case OP_UGT:
case OP_UGEQ: {
SASSERT(n_args == 2);
const mpz & x = m_tracker.get_value(args[0]);
const mpz & y = m_tracker.get_value(args[1]);
if ((k == OP_ULT && m_mpz_manager.lt(x, y)) ||
(k == OP_ULEQ && m_mpz_manager.le(x, y)) ||
(k == OP_UGT && m_mpz_manager.gt(x, y)) ||
(k == OP_UGEQ && m_mpz_manager.ge(x, y)))
m_mpz_manager.set(result, m_one);
break;
}
case OP_SLT:
case OP_SLEQ:
case OP_SGT:
case OP_SGEQ: {
SASSERT(n_args == 2);
mpz x; m_mpz_manager.set(x, m_tracker.get_value(args[0]));
mpz y; m_mpz_manager.set(y, m_tracker.get_value(args[1]));
unsigned bv_sz = m_bv_util.get_bv_size(args[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 ((k == OP_SLT && m_mpz_manager.lt(x, y)) ||
(k == OP_SLEQ && m_mpz_manager.le(x, y)) ||
(k == OP_SGT && m_mpz_manager.gt(x, y)) ||
(k == OP_SGEQ && m_mpz_manager.ge(x, y)))
m_mpz_manager.set(result, m_one);
m_mpz_manager.del(x);
m_mpz_manager.del(y);
break;
}
case OP_BIT2BOOL: {
SASSERT(n_args == 1);
const mpz & child = m_tracker.get_value(args[0]);
m_mpz_manager.set(result, child);
break;
}
case OP_BASHR: {
SASSERT(n_args == 2);
m_mpz_manager.set(result, m_tracker.get_value(args[0]));
mpz first;
const mpz & p = m_powers(m_bv_util.get_bv_size(args[0])-1);
m_mpz_manager.bitwise_and(result, p, first);
mpz shift; m_mpz_manager.set(shift, m_tracker.get_value(args[1]));
mpz temp;
while (!m_mpz_manager.is_zero(shift)) {
m_mpz_manager.machine_div(result, m_two, temp);
m_mpz_manager.add(temp, first, result);
m_mpz_manager.dec(shift);
}
m_mpz_manager.del(first);
m_mpz_manager.del(shift);
m_mpz_manager.del(temp);
break;
}
case OP_BLSHR: {
SASSERT(n_args == 2);
m_mpz_manager.set(result, m_tracker.get_value(args[0]));
mpz shift; m_mpz_manager.set(shift, m_tracker.get_value(args[1]));
while (!m_mpz_manager.is_zero(shift)) {
m_mpz_manager.machine_div(result, m_two, result);
m_mpz_manager.dec(shift);
}
m_mpz_manager.del(shift);
break;
}
case OP_BSHL: {
SASSERT(n_args == 2);
m_mpz_manager.set(result, m_tracker.get_value(args[0]));
mpz shift; m_mpz_manager.set(shift, m_tracker.get_value(args[1]));
while (!m_mpz_manager.is_zero(shift)) {
m_mpz_manager.mul(result, m_two, result);
m_mpz_manager.dec(shift);
}
const mpz & p = m_powers(m_bv_util.get_bv_size(n));
m_mpz_manager.rem(result, p, result);
m_mpz_manager.del(shift);
break;
}
case OP_SIGN_EXT: {
SASSERT(n_args == 1);
m_mpz_manager.set(result, m_tracker.get_value(args[0]));
break;
}
default:
NOT_IMPLEMENTED_YET();
}
}
else {
NOT_IMPLEMENTED_YET();
}
TRACE("sls_eval", tout << "(" << fd->get_name();
for (unsigned i = 0; i < n_args; i++)
tout << " " << m_mpz_manager.to_string(m_tracker.get_value(args[i]));
tout << ") ---> " << m_mpz_manager.to_string(result);
if (m_manager.is_bool(fd->get_range())) tout << " [Boolean]";
else tout << " [vector size: " << m_bv_util.get_bv_size(fd->get_range()) << "]";
tout << std::endl; );
SASSERT(m_mpz_manager.is_nonneg(result));
}
};
class score_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;
vector<ptr_vector<expr> > m_traversal_stack;
evaluator m_sls_evaluator;
mpz m_zero, m_one, m_two;
model m_dummy_model;
model_evaluator m_evaluator;
expr_ref_buffer m_temp_exprs;
struct value_score {
value_score() : m(0), value(unsynch_mpz_manager::mk_z(0)), score(0.0), distance(0) { };
~value_score() { if (m) m->del(value); }
unsynch_mpz_manager * m;
mpz value;
double score;
unsigned distance; // max distance from any root
value_score & operator=(const value_score & other) {
SASSERT(m == 0 || m == other.m);
if (m) m->set(value, 0); else m = other.m;
m->set(value, other.value);
score = other.score;
distance = other.distance;
return *this;
}
};
typedef obj_map<expr, value_score> scores_type;
typedef obj_map<expr, ptr_vector<expr> > uplinks_type;
typedef obj_map<func_decl, expr* > entry_point_type;
typedef obj_map<expr, ptr_vector<func_decl> > occ_type;
scores_type m_scores;
uplinks_type m_uplinks;
entry_point_type m_entry_points;
ptr_vector<func_decl> m_constants;
ptr_vector<func_decl> m_temp_constants;
occ_type m_constants_occ;
public:
score_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_sls_evaluator(m, m_bv_util, *this, m_mpz_manager, p),
m_zero(m_mpz_manager.mk_z(0)),
m_one(m_mpz_manager.mk_z(1)),
m_two(m_mpz_manager.mk_z(2)),
m_dummy_model(m),
m_evaluator(m_dummy_model),
m_temp_exprs(m) {
}
~score_tracker() {
m_mpz_manager.del(m_zero);
m_mpz_manager.del(m_one);
m_mpz_manager.del(m_two);
}
void set_value(expr * n, const mpz & r) {
SASSERT(m_scores.contains(n));
m_mpz_manager.set(m_scores.find(n).value, r);
}
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);
}
mpz & get_value(expr * n) {
SASSERT(m_scores.contains(n));
return m_scores.find(n).value;
}
mpz & get_value(func_decl * fd) {
SASSERT(m_entry_points.contains(fd));
expr * ep = get_entry_point(fd);
return get_value(ep);
}
void set_score(expr * n, double score) {
SASSERT(m_scores.contains(n));
m_scores.find(n).score = score;
}
void set_score(func_decl * fd, double score) {
SASSERT(m_entry_points.contains(fd));
expr * ep = get_entry_point(fd);
set_score(ep, score);
}
double & get_score(expr * n) {
SASSERT(m_scores.contains(n));
return m_scores.find(n).score;
}
double & get_score(func_decl * fd) {
SASSERT(m_entry_points.contains(fd));
expr * ep = get_entry_point(fd);
return get_score(ep);
}
unsigned get_distance(expr * n) {
SASSERT(m_scores.contains(n));
return m_scores.find(n).distance;
}
void set_distance(expr * n, unsigned d) {
SASSERT(m_scores.contains(n));
m_scores.find(n).distance = d;
}
expr * get_entry_point(func_decl * fd) {
SASSERT(m_entry_points.contains(fd));
return m_entry_points.find(fd);
}
bool has_uplinks(expr * n) {
return m_uplinks.contains(n);
}
ptr_vector<expr> & get_uplinks(expr * n) {
SASSERT(m_uplinks.contains(n));
return m_uplinks.find(n);
}
void initialize(app * n) {
// Build score table
if (!m_scores.contains(n)) {
value_score vs;
vs.m = & m_mpz_manager;
m_scores.insert(n, vs);
}
// Update uplinks
unsigned na = n->get_num_args();
for (unsigned i = 0; i < na; i++) {
expr * c = n->get_arg(i);
uplinks_type::obj_map_entry * entry = m_uplinks.insert_if_not_there2(c, ptr_vector<expr>());
entry->get_data().m_value.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;
score_tracker & m_tracker;
init_proc(ast_manager & m, score_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<func_decl> & m_occs;
find_func_decls_proc (ast_manager & m, ptr_vector<func_decl> & 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(goal_ref const & g) {
// precondition: m_scores is set up.
unsigned sz = g->size();
ptr_vector<app> stack;
for (unsigned i = 0; i < sz; i++)
stack.push_back(to_app(g->form(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);
}
}
}
}
void initialize(goal_ref const & g) {
init_proc proc(m_manager, *this);
expr_mark visited;
unsigned sz = g->size();
for (unsigned i = 0; i < sz; i++) {
expr * e = g->form(i);
for_each_expr(proc, visited, e);
}
visited.reset();
for (unsigned i = 0; i < sz; i++) {
expr * e = g->form(i);
ptr_vector<func_decl> 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(g);
TRACE("sls", tout << "Initial model:" << std::endl; show_model(tout); );
}
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;
}
}
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<func_decl> & 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 get_random_bool();
else
NOT_IMPLEMENTED_YET(); // This only works for bit-vectors for now.
}
void randomize() {
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 randomize_local(goal_ref const & g) {
ptr_vector<func_decl> & unsat_constants = get_unsat_constants(g);
bool did_something = false;
for (unsigned i = 0; i < unsat_constants.size(); i++) {
func_decl * fd = unsat_constants[i];
mpz temp = get_random(fd->get_range());
if (m_mpz_manager.neq(temp, get_value(fd)))
did_something = true;
update(fd, temp);
m_mpz_manager.del(temp);
}
TRACE("sls", tout << "Randomization candidates: ";
for (unsigned i = 0; i < unsat_constants.size(); i++)
tout << unsat_constants[i]->get_name() << ", ";
tout << std::endl;
tout << "Locally randomized model: " << std::endl; show_model(tout); );
}
#define _SCORE_AND_MIN
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();
#ifdef _SCORE_AND_MIN
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
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();
#endif
}
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);
#if 1 // unweighted hamming distance
while (!m_mpz_manager.is_zero(diff)) {
//m_mpz_manager.set(diff_m1, diff);
//m_mpz_manager.dec(diff_m1);
//m_mpz_manager.bitwise_and(diff, diff_m1, diff);
//hamming_distance++;
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);
#else
rational r(diff);
r /= m_powers(bv_sz);
double dbl = r.get_double();
res = (dbl < 0.0) ? 1.0 : (dbl > 1.0) ? 0.0 : 1.0 - dbl;
#endif
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));
unsigned 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) ? 1.0 : (dbl < 0.0) ? 0.0 : 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);
rational n(diff);
n /= p;
double dbl = n.get_double();
res = (dbl > 1.0) ? 1.0 : (dbl < 0.0) ? 0.0 : 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);
if (m_manager.is_and(child) || m_manager.is_or(child)) // Precondition: Assertion set is in NNF.
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);
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();
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;
}
void eval(expr * n, mpz & result) {
switch(n->get_kind()) {
case AST_APP: {
app * a = to_app(n);
unsigned n_args = a->get_num_args();
if (n_args == 0) {
m_mpz_manager.set(result, get_value(n));
}
else {
m_sls_evaluator(a, result);
//#define _EVAL_CHECKED
#ifdef _EVAL_CHECKED
m_temp_exprs.reset();
for (unsigned i = 0; i < n_args; i++) {
expr * arg = a->get_arg(i);
const mpz & v = get_value(arg);
m_temp_exprs.push_back(mpz2value(m_manager.get_sort(arg), v));
}
expr_ref q(m_manager), temp(m_manager);
q = m_manager.mk_app(fd, m_temp_exprs.size(), m_temp_exprs.c_ptr());
m_evaluator(q, temp);
mpz check_res;
value2mpz(temp, check_res);
if (!m_mpz_manager.eq(check_res, result))
TRACE("sls", tout << "EVAL BUG: IS " << m_mpz_manager.to_string(result) <<
" SHOULD BE " << m_mpz_manager.to_string(check_res) << std::endl; );
SASSERT(m_mpz_manager.eq(check_res, result));
m_mpz_manager.del(check_res);
#endif
}
break;
}
default:
NOT_IMPLEMENTED_YET();
}
// TRACE("sls", tout << "EVAL: " << mk_ismt2_pp(n, m_manager) << " IS " << res << std::endl;);
}
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();
}
void run_update(unsigned cur_depth) {
// precondition: m_traversal_stack contains the entry point(s)
expr_fast_mark1 visited;
mpz new_value;
SASSERT(cur_depth < m_traversal_stack.size());
while (cur_depth != static_cast<unsigned>(-1)) {
ptr_vector<expr> & cur_depth_exprs = m_traversal_stack[cur_depth];
for (unsigned i = 0; i < cur_depth_exprs.size(); i++) {
expr * cur = cur_depth_exprs[i];
eval(cur, new_value);
set_value(cur, new_value);
set_score(cur, score(cur));
if (has_uplinks(cur)) {
ptr_vector<expr> & ups = get_uplinks(cur);
for (unsigned j = 0; j < ups.size(); j++) {
expr * next = ups[j];
unsigned next_d = get_distance(next);
SASSERT(next_d < cur_depth);
if (!visited.is_marked(next)) {
m_traversal_stack[next_d].push_back(next);
visited.mark(next);
}
}
}
}
cur_depth_exprs.reset();
cur_depth--;
}
m_mpz_manager.del(new_value);
}
void update_all() {
unsigned max_depth = 0;
for (entry_point_type::iterator it = m_entry_points.begin();
it != m_entry_points.end();
it++) {
expr * ep = get_entry_point(it->m_key);
unsigned cur_depth = get_distance(ep);
if (m_traversal_stack.size() <= cur_depth)
m_traversal_stack.resize(cur_depth+1);
m_traversal_stack[cur_depth].push_back(ep);
if (cur_depth > max_depth) max_depth = cur_depth;
}
run_update(max_depth);
}
void update(func_decl * fd, const mpz & new_value) {
set_value(fd, new_value);
expr * ep = get_entry_point(fd);
unsigned cur_depth = get_distance(ep);
if (m_traversal_stack.size() <= cur_depth)
m_traversal_stack.resize(cur_depth+1);
m_traversal_stack[cur_depth].push_back(ep);
run_update(cur_depth);
}
ptr_vector<func_decl> & get_unsat_constants(goal_ref const & g) {
unsigned sz = g->size();
if (sz == 1) {
return get_constants();
}
else {
m_temp_constants.reset();
for (unsigned i = 0; i < sz; i++) {
expr * q = g->form(i);
if (m_mpz_manager.eq(get_value(q), m_one))
continue;
ptr_vector<func_decl> 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;
}
}
};
ast_manager & m_manager;
stats & m_stats;
unsynch_mpz_manager m_mpz_manager;
powers m_powers;
mpz m_zero, m_one, m_two;
bool m_produce_models;
volatile bool m_cancel;
bv_util m_bv_util;
score_tracker m_tracker;
unsigned m_max_restarts;
unsigned m_plateau_limit;
typedef enum { MV_FLIP = 0, MV_INC, MV_DEC, MV_INV } move_type;
imp(ast_manager & m, params_ref const & p, stats & s) :
m_manager(m),
m_stats(s),
m_powers(m_mpz_manager),
m_zero(m_mpz_manager.mk_z(0)),
m_one(m_mpz_manager.mk_z(1)),
m_two(m_mpz_manager.mk_z(2)),
m_bv_util(m),
m_tracker(m, m_bv_util, m_mpz_manager, m_powers)
{
updt_params(p);
}
~imp() {
m_mpz_manager.del(m_zero);
m_mpz_manager.del(m_one);
m_mpz_manager.del(m_two);
}
ast_manager & m() const { return m_manager; }
void set_cancel(bool f) { m_cancel = f; }
void cancel() { set_cancel(true); }
void reset_cancel() { set_cancel(false); }
static void collect_param_descrs(param_descrs & r) {
insert_produce_models(r);
r.insert(":sls-restarts", CPK_UINT, "(default: infty) # of SLS restarts.");
r.insert(":random-seed", CPK_UINT, "(default: 0) random seed.");
r.insert(":plateau-limit", CPK_UINT, "(default: 100) SLS plateau limit.");
}
void updt_params(params_ref const & p) {
m_produce_models = p.get_bool(":produce-models", false);
m_max_restarts = p.get_uint(":sls-restarts", -1);
m_tracker.set_random_seed(p.get_uint(":random-seed", 0));
m_plateau_limit = p.get_uint(":plateau-limit", 100);
}
void checkpoint() {
if (m_cancel)
throw tactic_exception(TACTIC_CANCELED_MSG);
cooperate("sls");
}
bool full_eval(goal_ref const & g, model & mdl) {
bool res = true;
unsigned sz = g->size();
for (unsigned i = 0; i < sz && res; i++) {
checkpoint();
expr_ref o(m_manager);
if (!mdl.eval(g->form(i), o, true))
exit(ERR_INTERNAL_FATAL);
res = m_manager.is_true(o.get());
}
TRACE("sls", tout << "Evaluation: " << res << std::endl;);
return res;
}
double top_score(goal_ref const & g) {
#if 0
double min = m_tracker.get_score(g->form(0));
unsigned sz = g->size();
for (unsigned i = 1; i < sz; i++) {
double q = m_tracker.get_score(g->form(i));
if (q < min) min = q;
}
TRACE("sls_top", tout << "Score distribution:";
for (unsigned i = 0; i < sz; i++)
tout << " " << m_tracker.get_score(g->form(i));
tout << " MIN: " << min << std::endl; );
return min;
#else
double top_sum = 0.0;
unsigned sz = g->size();
for (unsigned i = 0; i < sz; i++) {
top_sum += m_tracker.get_score(g->form(i));
}
TRACE("sls_top", tout << "Score distribution:";
for (unsigned i = 0; i < sz; i++)
tout << " " << m_tracker.get_score(g->form(i));
tout << " AVG: " << top_sum / (double) sz << std::endl; );
return top_sum / (double) sz;
#endif
}
double rescore(goal_ref const & g) {
m_tracker.update_all();
m_stats.m_full_evals++;
return top_score(g);
}
double incremental_score(goal_ref const & g, func_decl * fd, const mpz & new_value) {
m_tracker.update(fd, new_value);
m_stats.m_incr_evals++;
return top_score(g);
}
bool what_if(goal_ref const & g, func_decl * fd, const unsigned & fd_inx, const mpz & temp,
double & best_score, unsigned & best_const, mpz & best_value) {
#ifdef _DEBUG
mpz old_value;
m_mpz_manager.set(old_value, m_tracker.get_value(fd));
#endif
double r = incremental_score(g, fd, temp);
#ifdef _DEBUG
TRACE("sls_whatif", tout << "WHAT IF " << fd->get_name() << " WERE " << m_mpz_manager.to_string(temp) <<
" --> " << r << std::endl; );
m_mpz_manager.del(old_value);
#endif
if (r >= best_score) {
best_score = r;
best_const = fd_inx;
m_mpz_manager.set(best_value, temp);
return true;
}
return false;
}
void mk_inc(unsigned bv_sz, const mpz & old_value, mpz & incremented) {
unsigned shift;
m_mpz_manager.add(old_value, m_one, incremented);
if (m_mpz_manager.is_power_of_two(incremented, shift) && shift == bv_sz)
m_mpz_manager.set(incremented, m_zero);
}
void mk_dec(unsigned bv_sz, const mpz & old_value, mpz & decremented) {
if (m_mpz_manager.is_zero(old_value)) {
m_mpz_manager.set(decremented, m_powers(bv_sz));
m_mpz_manager.dec(decremented);
}
else
m_mpz_manager.sub(old_value, m_one, decremented);
}
void mk_inv(unsigned bv_sz, const mpz & old_value, mpz & inverted) {
m_mpz_manager.bitwise_not(bv_sz, old_value, inverted);
}
void mk_flip(sort * s, const mpz & old_value, unsigned bit, mpz & flipped) {
m_mpz_manager.set(flipped, m_zero);
if (m_bv_util.is_bv_sort(s)) {
mpz mask;
m_mpz_manager.set(mask, m_powers(bit));
m_mpz_manager.bitwise_xor(old_value, mask, flipped);
m_mpz_manager.del(mask);
}
else if (m_manager.is_bool(s))
m_mpz_manager.set(flipped, (m_mpz_manager.is_zero(old_value)) ? m_one : m_zero);
else
NOT_IMPLEMENTED_YET();
}
void mk_random_move(goal_ref const & g) {
unsigned rnd_mv = 0;
if (m_mpz_manager.is_one(m_tracker.get_random_bool())) rnd_mv=2;
if (m_mpz_manager.is_one(m_tracker.get_random_bool())) rnd_mv++;
move_type mt = (move_type) rnd_mv;
// inversion doesn't make sense, let's do a flip instead.
if (mt == MV_INV) mt = MV_FLIP;
ptr_vector<func_decl> & unsat_constants = m_tracker.get_unsat_constants(g);
unsigned ucc = unsat_constants.size();
unsigned rc = (m_tracker.get_random_uint((ucc < 16) ? 4 : (ucc < 256) ? 8 : (ucc < 4096) ? 12 : (ucc < 65536) ? 16 : 32)) % ucc;
func_decl * fd = unsat_constants[rc];
mpz new_value;
unsigned bit = 0;
switch (mt)
{
case MV_FLIP: {
unsigned bv_sz = m_bv_util.get_bv_size(fd->get_range());
bit = (m_tracker.get_random_uint((bv_sz < 16) ? 4 : (bv_sz < 256) ? 8 : (bv_sz < 4096) ? 12 : (bv_sz < 65536) ? 16 : 32)) % bv_sz;
mk_flip(fd->get_range(), m_tracker.get_value(fd), bit, new_value);
break;
}
case MV_INC:
mk_inc(m_bv_util.get_bv_size(fd->get_range()), m_tracker.get_value(fd), new_value);
break;
case MV_DEC:
mk_dec(m_bv_util.get_bv_size(fd->get_range()), m_tracker.get_value(fd), new_value);
break;
case MV_INV:
mk_inv(m_bv_util.get_bv_size(fd->get_range()), m_tracker.get_value(fd), new_value);
break;
default:
NOT_IMPLEMENTED_YET();
}
m_tracker.update(fd, new_value);
TRACE("sls", tout << "Randomization candidates: ";
for (unsigned i = 0; i < unsat_constants.size(); i++)
tout << unsat_constants[i]->get_name() << ", ";
tout << std::endl;
tout << "Random move: ";
switch (mt) {
case MV_FLIP: tout << "Flip #" << bit << " in " << fd->get_name() << std::endl; break;
case MV_INC: tout << "+1 for " << fd->get_name() << std::endl; break;
case MV_DEC: tout << "-1 for " << fd->get_name() << std::endl; break;
case MV_INV: tout << "NEG for " << fd->get_name() << std::endl; break;
}
tout << "Locally randomized model: " << std::endl; m_tracker.show_model(tout); );
m_mpz_manager.del(new_value);
}
double find_best_move(goal_ref const & g, ptr_vector<func_decl> & to_evaluate, double score,
unsigned & best_const, mpz & best_value, unsigned & new_bit, move_type & move) {
mpz old_value, temp;
unsigned bv_sz;
double new_score = score;
for (unsigned i = 0; i < to_evaluate.size() && new_score < 1.0 ; i++) {
func_decl * fd = to_evaluate[i];
sort * srt = fd->get_range();
bv_sz = (m_manager.is_bool(srt)) ? 1 : m_bv_util.get_bv_size(srt);
m_mpz_manager.set(old_value, m_tracker.get_value(fd));
// first try to flip every bit
for (unsigned j = 0; j < bv_sz && new_score < 1.0; j++) {
// What would happen if we flipped bit #i ?
mk_flip(srt, old_value, j, temp);
if (what_if(g, fd, i, temp, new_score, best_const, best_value)) {
new_bit = j;
move = MV_FLIP;
}
}
if (m_bv_util.is_bv_sort(srt) && bv_sz > 1) {
if (!m_mpz_manager.is_even(old_value)) {
// for odd values, try +1
mk_inc(bv_sz, old_value, temp);
if (what_if(g, fd, i, temp, new_score, best_const, best_value))
move = MV_INC;
}
else {
// for even values, try -1
mk_dec(bv_sz, old_value, temp);
if (what_if(g, fd, i, temp, new_score, best_const, best_value))
move = MV_DEC;
}
// try inverting
mk_inv(bv_sz, old_value, temp);
if (what_if(g, fd, i, temp, new_score, best_const, best_value))
move = MV_INV;
}
// reset to what it was before
double check = incremental_score(g, fd, old_value);
SASSERT(check == score);
}
m_mpz_manager.del(old_value);
m_mpz_manager.del(temp);
return new_score;
}
lbool search(goal_ref const & g) {
lbool res = l_undef;
double score = 0.0, old_score = 0.0;
unsigned new_const = -1, new_bit = 0;
mpz new_value;
move_type move;
score = rescore(g);
TRACE("sls", tout << "Starting search, initial score = " << std::setprecision(32) << score << std::endl;
tout << "Score distribution:";
for (unsigned i = 0; i < g->size(); i++)
tout << " " << std::setprecision(3) << m_tracker.get_score(g->form(i));
tout << " TOP: " << score << std::endl; );
unsigned plateau_cnt = 0;
while (plateau_cnt < m_plateau_limit) {
do {
checkpoint();
old_score = score;
new_const = -1;
ptr_vector<func_decl> & to_evaluate = m_tracker.get_unsat_constants(g);
TRACE("sls_constants", tout << "Evaluating these constants: " << std::endl;
for (unsigned i = 0 ; i < to_evaluate.size(); i++)
tout << to_evaluate[i]->get_name() << std::endl; );
score = find_best_move(g, to_evaluate, score, new_const, new_value, new_bit, move);
if (new_const == static_cast<unsigned>(-1)) {
TRACE("sls", tout << "Local maximum reached; unsatisfied constraints: " << std::endl;
for (unsigned i = 0; i < g->size(); i++) {
if (!m_mpz_manager.is_one(m_tracker.get_value(g->form(i))))
tout << mk_ismt2_pp(g->form(i), m_manager) << std::endl;
});
TRACE("sls_max", m_tracker.show_model(tout);
tout << "Scores: " << std::endl;
for (unsigned i = 0; i < g->size(); i++)
tout << mk_ismt2_pp(g->form(i), m_manager) << " ---> " <<
m_tracker.get_score(g->form(i)) << std::endl; );
score = old_score;
}
else {
m_stats.m_moves++;
func_decl * fd = to_evaluate[new_const];
TRACE("sls", tout << "Setting " << fd->get_name() << " to " << m_mpz_manager.to_string(new_value) << " (Move: ";
switch (move) {
case MV_FLIP:
tout << "Flip";
if (!m_manager.is_bool(fd->get_range())) tout << " #" << new_bit;
break;
case MV_INC:
tout << "+1";
break;
case MV_DEC:
tout << "-1";
break;
case MV_INV:
tout << "NEG";
break;
};
tout << ") ; new score = " << std::setprecision(32) << score << std::endl; );
switch (move) {
case MV_FLIP: m_stats.m_flips++; break;
case MV_INC: m_stats.m_incs++; break;
case MV_DEC: m_stats.m_decs++; break;
case MV_INV: m_stats.m_invs++; break;
}
score = incremental_score(g, fd, new_value);
TRACE("sls", tout << "Score distribution:";
for (unsigned i = 0; i < g->size(); i++)
tout << " " << std::setprecision(3) << m_tracker.get_score(g->form(i));
tout << " TOP: " << score << std::endl; );
}
if (score >= 1.0) {
// score could theoretically be imprecise.
bool all_true = true;
for (unsigned i = 0; i < g->size() && all_true; i++)
if (!m_mpz_manager.is_one(m_tracker.get_value(g->form(i))))
all_true=false;
if (all_true) {
res = l_true; // sat
goto bailout;
} else
TRACE("sls", tout << "Imprecise 1.0 score" << std::endl;);
}
}
while (score > old_score && res == l_undef);
if (score != old_score)
plateau_cnt = 0;
else {
plateau_cnt++;
if (plateau_cnt < m_plateau_limit) {
m_tracker.randomize_local(g);
//mk_random_move(g);
score = top_score(g);
}
}
}
bailout:
m_mpz_manager.del(new_value);
return res;
}
void operator()(goal_ref const & g, model_converter_ref & mc) {
//#ifdef _DEBUG
//ptr_vector<expr> es;
//for (unsigned i = 0; i < g->size(); i++)
// es.push_back(g->form(i));
//expr_ref a(m_manager);
//a = m_manager.mk_and(g->size(), es.c_ptr());
//std::ofstream dot_out("top.dot", std::ios::out);
//expr2dot(dot_out, a, m_manager);
//dot_out.close();
//#endif
if (g->inconsistent()) {
mc = 0;
return;
}
m_tracker.initialize(g);
lbool res = l_undef;
do {
checkpoint();
if ((m_stats.m_restarts % 100) == 0)
report_tactic_progress("Searching... restarts left:", m_max_restarts - m_stats.m_restarts);
res = search(g);
if (res == l_undef)
m_tracker.randomize();
}
while (res != l_true && m_stats.m_restarts++ < m_max_restarts);
if (res == l_true) {
if (m_produce_models) {
model_ref mdl = m_tracker.get_model();
mc = model2model_converter(mdl.get());
TRACE("sls_model", mc->display(tout); );
}
g->reset();
}
else
mc = 0;
}
};
ast_manager & m;
params_ref m_params;
imp * m_imp;
stats m_stats;
public:
sls_tactic(ast_manager & _m, params_ref const & p):
m(_m),
m_params(p) {
m_imp = alloc(imp, m, p, m_stats);
}
virtual tactic * translate(ast_manager & m) {
return alloc(sls_tactic, m, m_params);
}
virtual ~sls_tactic() {
dealloc(m_imp);
}
virtual void updt_params(params_ref const & p) {
m_params = p;
m_imp->updt_params(p);
}
virtual void collect_param_descrs(param_descrs & r) {
imp::collect_param_descrs(r);
}
virtual void operator()(goal_ref const & g,
goal_ref_buffer & result,
model_converter_ref & mc,
proof_converter_ref & pc,
expr_dependency_ref & core) {
SASSERT(g->is_well_sorted());
m_imp->m_produce_models = g->models_enabled();
mc = 0; pc = 0; core = 0; result.reset();
TRACE("sls", g->display(tout););
tactic_report report("sls", *g);
m_imp->operator()(g, mc);
g->inc_depth();
result.push_back(g.get());
TRACE("sls", g->display(tout););
SASSERT(g->is_well_sorted());
}
virtual void cleanup() {
imp * d = m_imp;
#pragma omp critical (tactic_cancel)
{
d = m_imp;
}
dealloc(d);
d = alloc(imp, m, m_params, m_stats);
#pragma omp critical (tactic_cancel)
{
m_imp = d;
}
}
virtual void collect_statistics(statistics & st) const {
double seconds = m_stats.m_stopwatch.get_current_seconds();
st.update("sls restarts", m_stats.m_restarts);
st.update("sls full evals", m_stats.m_full_evals);
st.update("sls incr evals", m_stats.m_incr_evals);
st.update("sls incr evals/sec", m_stats.m_incr_evals/ seconds);
st.update("sls FLIP moves", m_stats.m_flips);
st.update("sls INC moves", m_stats.m_incs);
st.update("sls DEC moves", m_stats.m_decs);
st.update("sls INV moves", m_stats.m_invs);
st.update("sls moves", m_stats.m_moves);
st.update("sls moves/sec", m_stats.m_moves / seconds);
}
virtual void reset_statistics() {
m_stats.reset();
}
virtual void set_cancel(bool f) {
if (m_imp)
m_imp->set_cancel(f);
}
};
tactic * mk_sls_tactic(ast_manager & m, params_ref const & p) {
return and_then(fail_if_not(mk_is_qfbv_probe()), // Currently only QF_BV is supported.
clean(alloc(sls_tactic, m, p)));
}
tactic * mk_preamble(ast_manager & m, params_ref const & p) {
params_ref main_p;
main_p.set_bool(":elim-and", true);
// main_p.set_bool(":pull-cheap-ite", true);
main_p.set_bool(":push-ite-bv", true);
main_p.set_bool(":blast-distinct", true);
// main_p.set_bool(":udiv2mul", true);
main_p.set_bool(":hi-div0", true);
params_ref simp2_p = p;
simp2_p.set_bool(":som", true);
simp2_p.set_bool(":pull-cheap-ite", true);
simp2_p.set_bool(":push-ite-bv", false);
simp2_p.set_bool(":local-ctx", true);
simp2_p.set_uint(":local-ctx-limit", 10000000);
params_ref hoist_p;
hoist_p.set_bool(":hoist-mul", true);
// hoist_p.set_bool(":hoist-cmul", true);
hoist_p.set_bool(":som", false);
params_ref gaussian_p;
// conservative gaussian elimination.
gaussian_p.set_uint(":gaussian-max-occs", 2);
return and_then(and_then(mk_simplify_tactic(m),
mk_propagate_values_tactic(m),
using_params(mk_solve_eqs_tactic(m), gaussian_p),
mk_elim_uncnstr_tactic(m),
mk_bv_size_reduction_tactic(m),
using_params(mk_simplify_tactic(m), simp2_p)),
using_params(mk_simplify_tactic(m), hoist_p),
mk_max_bv_sharing_tactic(m),
mk_nnf_tactic(m, p));
}
tactic * mk_qfbv_sls_tactic(ast_manager & m, params_ref const & p) {
params_ref sls_p(p);
sls_p.set_uint(":sls-restarts", 10000);
sls_p.set_uint(":plateau-limit", 100);
tactic * t = and_then(mk_preamble(m, p),
using_params(mk_sls_tactic(m, p), sls_p));
t->updt_params(p);
return t;
}