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integrate lookahead v1 into repair loop

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this ports some functionality from lookahead solver for qfbv-sls into sls-smt.
This commit is contained in:
Nikolaj Bjorner 2024-12-26 17:49:30 -08:00
parent c58171478f
commit 5eb71c3be6
9 changed files with 214 additions and 104 deletions
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3
src/ast/sls/sls_bv_engine.h
View file

@ -21,7 +21,6 @@ Notes:
#include "util/stopwatch.h"
#include "util/lbool.h"
#include "ast/converters/model_converter.h"
#include "ast/sls/sls_stats.h"
#include "ast/sls/sls_bv_tracker.h"
#include "ast/sls/sls_bv_evaluator.h"
@ -79,8 +78,6 @@ public:
void mk_inv(unsigned bv_sz, const mpz & old_value, mpz & inverted);
void mk_flip(sort * s, const mpz & old_value, unsigned bit, mpz & flipped);
lbool search();
lbool search_loop();

41
src/ast/sls/sls_bv_eval.cpp
View file

@ -88,7 +88,6 @@ namespace sls {
return r;
}
void bv_eval::init_eval_bv(app* e) {
if (bv.is_bv(e))
eval(e).commit_eval();
@ -99,7 +98,7 @@ namespace sls {
if (m.is_eq(e, x, y))
return bv.is_bv(x);
if (m.is_ite(e))
return bv.is_bv(e->get_arg(0));
return bv.is_bv(e->get_arg(1));
if (e->get_family_id() == bv.get_fid()) {
switch (e->get_decl_kind()) {
case OP_BNEG_OVFL:
@ -680,6 +679,8 @@ namespace sls {
expr* arg = e->get_arg(i);
if (m.is_value(arg))
return false;
if (m.is_bool(e) && false && m_rand(10) == 0 && m_lookahead.try_repair_down(e))
return true;
if (e->get_family_id() == bv.get_family_id() && try_repair_bv(e, i)) {
commit_eval(e, to_app(arg));
IF_VERBOSE(11, verbose_stream() << "repair " << mk_bounded_pp(e, m) << " : " << mk_bounded_pp(arg, m) << " := " << wval(arg) << "\n";);
@ -692,9 +693,9 @@ namespace sls {
ctx.new_value_eh(arg);
return true;
}
if (m.is_eq(e) && bv.is_bv(arg)) {
return try_repair_eq_lookahead(e);
}
if (m.is_bool(e) && m_lookahead.try_repair_down(e))
return true;
return false;
}
@ -882,37 +883,9 @@ namespace sls {
return false;
}
bool bv_eval::try_repair_eq_lookahead(app* e) {
return m_lookahead.try_repair_down(e);
}
bool bv_eval::try_repair_eq(bool is_true, bvval& a, bvval const& b) {
if (is_true) {
#if 0
if (bv.is_bv_add(t)) {
bvval tmp(b);
unsigned start = m_rand();
unsigned sz = to_app(t)->get_num_args();
for (unsigned i = 0; i < sz; ++i) {
unsigned j = (start + i) % sz;
for (unsigned k = 0; k < sz; ++k) {
if (k == j)
continue;
auto& c = wval(to_app(t)->get_arg(k));
set_sub(tmp, tmp, c.bits());
}
auto& c = wval(to_app(t)->get_arg(j));
verbose_stream() << "TRY " << c << " := " << tmp << "\n";
}
}
#endif
if (m_rand(20) != 0 && a.try_set(b.bits()))
return true;
return a.set_random(m_rand);
return (m_rand(20) != 0 && a.try_set(b.bits())) || a.set_random(m_rand);
}
else {
bool try_above = m_rand(2) == 0;

1
src/ast/sls/sls_bv_eval.h
View file

@ -121,7 +121,6 @@ namespace sls {
bool try_repair_comp(bvect const& e, bvval& a, bvval& b, unsigned i);
bool try_repair_eq(bool is_true, bvval& a, bvval const& b);
bool try_repair_eq(app* e, unsigned i);
bool try_repair_eq_lookahead(app* e);
bool try_repair_int2bv(bvect const& e, expr* arg);
void add_p2_1(bvval const& a, bool use_current, bvect& t) const;

35
src/ast/sls/sls_bv_evaluator.h
View file

@ -451,25 +451,34 @@ public:
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);
auto const& shift = m_tracker.get_value(args[1]);
if (m_mpz_manager.is_small(shift)) {
int s = m_mpz_manager.get_int(shift);
SASSERT(s >= 0);
m_mpz_manager.machine_div2k(result, s);
}
m_mpz_manager.del(shift);
else
m_mpz_manager.set(result, m_zero);
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);
m_mpz_manager.set(result, m_tracker.get_value(args[0]));
auto const& shift = m_tracker.get_value(args[1]);
if (m_mpz_manager.is_small(shift)) {
int s = m_mpz_manager.get_int(shift);
SASSERT(s >= 0);
int sz = m_bv_util.get_bv_size(n);
if (s >= sz)
m_mpz_manager.set(result, m_zero);
else {
m_mpz_manager.mul2k(result, s);
const mpz& p = m_powers(sz);
m_mpz_manager.rem(result, p, result);
}
}
const mpz & p = m_powers(m_bv_util.get_bv_size(n));
m_mpz_manager.rem(result, p, result);
m_mpz_manager.del(shift);
else
m_mpz_manager.set(result, m_zero);
break;
}
case OP_SIGN_EXT: {

168
src/ast/sls/sls_bv_lookahead.cpp
View file

@ -18,45 +18,43 @@ Author:
#include "ast/sls/sls_bv_lookahead.h"
#include "ast/sls/sls_bv_eval.h"
#include "ast/sls/sls_bv_terms.h"
#include "ast/ast_pp.h"
namespace sls {
bv_lookahead::bv_lookahead(bv_eval& ev) :
bv(ev.bv),
bv(ev.m),
m_ev(ev),
ctx(ev.ctx),
m(ev.m) {}
bool bv_lookahead::try_repair_down(expr* e) {
return false;
auto is_true = m_ev.bval0(e);
if (!is_true)
bool bv_lookahead::try_repair_down(app* e) {
if (!m.is_bool(e))
return false;
if (m_ev.bval1(e) == m_ev.bval0(e))
return true;
auto const& uninterp = m_ev.terms.uninterp_occurs(e);
if (uninterp.empty())
return false;
// for (auto e : uninterp)
// verbose_stream() << mk_bounded_pp(e, m) << " ";
// verbose_stream() << "\n";
reset_updates();
expr* t = uninterp[m_ev.m_rand() % uninterp.size()];
IF_VERBOSE(4,
verbose_stream() << mk_bounded_pp(e, m) << "\n";
for (auto e : uninterp)
verbose_stream() << mk_bounded_pp(e, m) << " ";
verbose_stream() << "\n");
auto& v = wval(t);
if (v.set_random(m_ev.m_rand)) {
//verbose_stream() << "set random " << mk_bounded_pp(t, m) << "\n";
ctx.new_value_eh(t);
return true;
for (auto e : uninterp)
add_updates(e);
#if 0
for (unsigned i = 0; i < m_num_updates; ++i) {
auto const& [e, score, new_value] = m_updates[i];
verbose_stream() << mk_bounded_pp(e, m) << " " << new_value << " score: " << score << "\n";
}
return false;
for (auto e : uninterp) {
auto& v = wval(e);
v.get_variant(m_ev.m_tmp, m_ev.m_rand);
auto d = lookahead(e, m_ev.m_tmp);
//verbose_stream() << mk_bounded_pp(e, m) << " " << d << "\n";
}
return false;
#endif
return apply_update();
}
double bv_lookahead::lookahead(expr* e, bvect const& new_value) {
@ -76,7 +74,7 @@ namespace sls {
unsigned max_depth = get_depth(e);
for (unsigned depth = max_depth; depth <= max_depth; ++depth) {
for (unsigned i = 0; !has_tabu && i < m_update_stack[depth].size(); ++i) {
e = m_update_stack[depth][i];
auto e = m_update_stack[depth][i];
if (bv.is_bv(e)) {
auto& v = m_ev.eval(to_app(e));
if (insert_update(e)) {
@ -89,24 +87,133 @@ namespace sls {
has_tabu = true;
}
else if (m.is_bool(e) && m_ev.can_eval1(to_app(e))) {
if (!ctx.is_relevant(e))
continue;
bool is_true = ctx.is_true(e);
bool is_true_new = m_ev.bval1(to_app(e));
bool is_true_old = m_ev.bval1_tmp(to_app(e));
// verbose_stream() << "parent " << mk_bounded_pp(e, m) << " " << is_true << " " << is_true_new << " " << is_true_old << "\n";
if (is_true == is_true_new && is_true_new != is_true_old)
if (is_true_new == is_true_old)
continue;
if (is_true == is_true_new)
++make_count;
if (is_true == is_true_old && is_true_new != is_true_old)
if (is_true == is_true_old)
++break_count;
}
else {
IF_VERBOSE(1, verbose_stream() << "skipping " << mk_bounded_pp(e, m) << "\n");
has_tabu = true;
}
}
m_update_stack[depth].reset();
}
restore_lookahead();
// verbose_stream() << has_tabu << " " << new_value << " " << make_count << " " << break_count << "\n";
if (has_tabu)
return -10000;
return make_count - break_count;
}
void bv_lookahead::try_set(expr* e, bvect const& new_value) {
if (!wval(e).can_set(new_value))
return;
auto d = lookahead(e, new_value);
if (d > 0)
add_update(d, e, new_value);
}
void bv_lookahead::add_updates(expr* e) {
SASSERT(bv.is_bv(e));
auto& v = wval(e);
double d = 0;
while (m_v_saved.size() < v.bits().size()) {
m_v_saved.push_back(0);
m_v_updated.push_back(0);
}
m_v_saved.set_bw(v.bw);
m_v_updated.set_bw(v.bw);
v.bits().copy_to(v.nw, m_v_saved);
m_v_saved.copy_to(v.nw, m_v_updated);
// flip a single bit
for (unsigned i = 0; i < v.bw; ++i) {
m_v_updated.set(i, !m_v_updated.get(i));
try_set(e, m_v_updated);
//verbose_stream() << "flip " << d << " " << m_v_updated << "\n";
m_v_updated.set(i, !m_v_updated.get(i));
}
if (v.bw <= 1)
return;
// invert
for (unsigned i = 0; i < v.nw; ++i)
m_v_updated[i] = ~m_v_updated[i];
v.clear_overflow_bits(m_v_updated);
try_set(e, m_v_updated);
// increment
m_v_saved.copy_to(v.nw, m_v_updated);
v.add1(m_v_updated);
try_set(e, m_v_updated);
// decrement
m_v_saved.copy_to(v.nw, m_v_updated);
v.sub1(m_v_updated);
try_set(e, m_v_updated);
// random
v.get_variant(m_v_updated, m_ev.m_rand);
try_set(e, m_v_updated);
}
bool bv_lookahead::apply_update() {
double sum_score = 0;
for (unsigned i = 0; i < m_num_updates; ++i)
sum_score += m_updates[i].score;
double pos = (sum_score * m_ev.m_rand()) / (double)m_ev.m_rand.max_value();
for (unsigned i = 0; i < m_num_updates; ++i) {
auto const& [e, score, new_value] = m_updates[i];
pos -= score;
if (pos <= 0) {
//verbose_stream() << "apply " << mk_bounded_pp(e, m) << " new value " << new_value << " " << score << "\n";
apply_update(e, new_value);
return true;
}
}
return false;
}
void bv_lookahead::apply_update(expr* e, bvect const& new_value) {
SASSERT(bv.is_bv(e));
SASSERT(is_uninterp(e));
SASSERT(m_restore.empty());
wval(e).eval = new_value;
VERIFY(wval(e).commit_eval());
insert_update_stack(e);
unsigned max_depth = get_depth(e);
for (unsigned depth = max_depth; depth <= max_depth; ++depth) {
for (unsigned i = 0; i < m_update_stack[depth].size(); ++i) {
auto e = m_update_stack[depth][i];
if (bv.is_bv(e)) {
m_ev.eval(to_app(e)); // updates wval(e).eval
VERIFY(wval(e).commit_eval());
for (auto p : ctx.parents(e)) {
insert_update_stack(p);
max_depth = std::max(max_depth, get_depth(p));
}
}
else if (m.is_bool(e) && m_ev.can_eval1(to_app(e))) {
VERIFY(m_ev.repair_up(e));
}
else {
UNREACHABLE();
}
}
m_update_stack[depth].reset();
}
m_in_update_stack.reset();
}
bool bv_lookahead::insert_update(expr* e) {
m_restore.push_back(e);
m_on_restore.mark(e);
@ -118,8 +225,10 @@ namespace sls {
void bv_lookahead::insert_update_stack(expr* e) {
unsigned depth = get_depth(e);
m_update_stack.reserve(depth + 1);
if (!m_update_stack[depth].contains(e))
if (!m_in_update_stack.is_marked(e)) {
m_in_update_stack.mark(e);
m_update_stack[depth].push_back(e);
}
}
void bv_lookahead::restore_lookahead() {
@ -127,6 +236,7 @@ namespace sls {
wval(e).restore_value();
m_restore.reset();
m_on_restore.reset();
m_in_update_stack.reset();
}
sls::bv_valuation& bv_lookahead::wval(expr* e) const {

38
src/ast/sls/sls_bv_lookahead.h
View file

@ -18,36 +18,60 @@ Author:
#include "ast/bv_decl_plugin.h"
#include "ast/sls/sls_context.h"
#include "ast/sls/sls_bv_valuation.h"
namespace sls {
class bv_eval;
class bv_valuation;
class bvect;
class bv_lookahead {
bv_util bv;
bv_eval& m_ev;
context& ctx;
ast_manager& m;
bvect m_v_saved, m_v_updated;
ptr_vector<expr> m_restore;
vector<ptr_vector<expr>> m_update_stack;
expr_mark m_on_restore;
expr_mark m_on_restore, m_in_update_stack;
struct update {
expr* e;
double score;
bvect value;
};
vector<update> m_updates;
unsigned m_num_updates = 0;
void reset_updates() { m_num_updates = 0; }
void add_update(double score, expr* e, bvect const& value) {
if (m_num_updates == m_updates.size())
m_updates.push_back({ e, score, value });
else {
auto& u = m_updates[m_num_updates];
u.e = e;
u.score = score;
u.value = value;
}
m_num_updates++;
}
bv_valuation& wval(expr* e) const;
void insert_update_stack(expr* e);
bool insert_update(expr* e);
bool insert_update(expr* e);
void restore_lookahead();
double lookahead(expr* e, bvect const& new_value);
void try_set(expr* e, bvect const& new_value);
void add_updates(expr* e);
void apply_update(expr* e, bvect const& new_value);
bool apply_update();
public:
bv_lookahead(bv_eval& ev);
bool on_restore(expr* e) const;
bool try_repair_down(expr* e);
bool try_repair_down(app* e);
};
}

5
src/ast/sls/sls_bv_terms.cpp
View file

@ -127,6 +127,7 @@ namespace sls {
ptr_vector<expr> todo;
todo.append(to_app(e)->get_num_args(), to_app(e)->get_args());
expr_mark marked;
expr* c, * th, * el;
for (unsigned i = 0; i < todo.size(); ++i) {
e = todo[i];
if (marked.is_marked(e))
@ -136,6 +137,10 @@ namespace sls {
for (expr* arg : *to_app(e))
todo.push_back(arg);
}
else if (m.is_ite(e, c, th, el)) {
todo.push_back(th);
todo.push_back(el);
}
else if (bv.is_bv(e))
occs.push_back(e);
}

24
src/ast/sls/sls_stats.h
View file

@ -6,24 +6,21 @@
namespace bv {
class sls_stats {
public:
unsigned m_restarts;
unsigned m_restarts = 0;
unsigned m_full_evals = 0;
unsigned m_incr_evals = 0;
unsigned m_moves = 0;
unsigned m_flips = 0;
unsigned m_incs = 0;
unsigned m_decs = 0;
unsigned m_invs = 0;
stopwatch m_stopwatch;
unsigned m_full_evals;
unsigned m_incr_evals;
unsigned m_moves, m_flips, m_incs, m_decs, m_invs;
sls_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) {
sls_stats() {
m_stopwatch.reset();
m_stopwatch.start();
}
void reset() {
m_full_evals = m_flips = m_incr_evals = 0;
m_stopwatch.reset();
@ -44,7 +41,6 @@ namespace bv {
st.update("sls DEC moves", m_decs);
st.update("sls INV moves", m_invs);
st.update("sls moves", m_moves);
}
};

3
src/tactic/sls/sls_tactic.cpp
View file

@ -213,9 +213,6 @@ public:
}
void cleanup() override {
sls_engine * d = alloc(sls_engine, m, m_params);
std::swap(d, m_engine);
dealloc(d);
}
void collect_statistics(statistics & st) const override {