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Merge branch 'opt' of https://github.com/nikolajbjorner/z3 into opt

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Nikolaj Bjorner 2017-01-30 18:42:53 -08:00
commit 1a95c33775
26 changed files with 1307 additions and 98 deletions
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1
src/api/c++/z3++.h
View file

@ -1816,6 +1816,7 @@ namespace z3 {
fmls,
fml));
}
param_descrs get_param_descrs() { return param_descrs(ctx(), Z3_solver_get_param_descrs(ctx(), m_solver)); }
};

6
src/api/python/z3/z3.py
View file

@ -2662,6 +2662,12 @@ class RatNumRef(ArithRef):
return self.denominator().as_long()
def is_int(self):
return False
def is_real(self):
return True
def is_int_value(self):
return self.denominator().is_int() and self.denominator_as_long() == 1
def as_long(self):

803
src/sat/card_extension.cpp Normal file
View file

@ -0,0 +1,803 @@
/*++
Copyright (c) 2017 Microsoft Corporation
Module Name:
card_extension.cpp
Abstract:
Extension for cardinality reasoning.
Author:
Nikolaj Bjorner (nbjorner) 2017-01-30
Revision History:
--*/
#include"card_extension.h"
#include"sat_types.h"
namespace sat {
card_extension::card::card(unsigned index, literal lit, literal_vector const& lits, unsigned k):
m_index(index),
m_lit(lit),
m_k(k),
m_size(lits.size()),
m_lits(lits) {
}
void card_extension::card::negate() {
m_lit.neg();
for (unsigned i = 0; i < m_size; ++i) {
m_lits[i].neg();
}
m_k = m_size - m_k + 1;
SASSERT(m_size >= m_k && m_k > 0);
}
void card_extension::init_watch(bool_var v) {
if (m_var_infos.size() <= static_cast<unsigned>(v)) {
m_var_infos.resize(static_cast<unsigned>(v)+100);
}
}
void card_extension::init_watch(card& c, bool is_true) {
clear_watch(c);
if (c.lit().sign() == is_true) {
c.negate();
}
SASSERT(value(c.lit()) == l_true);
unsigned j = 0, sz = c.size(), bound = c.k();
if (bound == sz) {
for (unsigned i = 0; i < sz && !s().inconsistent(); ++i) {
assign(c, c[i]);
}
return;
}
// put the non-false literals into the head.
for (unsigned i = 0; i < sz; ++i) {
if (value(c[i]) != l_false) {
if (j != i) {
c.swap(i, j);
}
++j;
}
}
DEBUG_CODE(
bool is_false = false;
for (unsigned k = 0; k < sz; ++k) {
SASSERT(!is_false || value(c[k]) == l_false);
is_false = value(c[k]) == l_false;
});
// j is the number of non-false, sz - j the number of false.
if (j < bound) {
SASSERT(0 < bound && bound < sz);
literal alit = c[j];
//
// we need the assignment level of the asserting literal to be maximal.
// such that conflict resolution can use the asserting literal as a starting
// point.
//
for (unsigned i = bound; i < sz; ++i) {
if (lvl(alit) < lvl(c[i])) {
c.swap(i, j);
alit = c[j];
}
}
set_conflict(c, alit);
}
else if (j == bound) {
for (unsigned i = 0; i < bound && !s().inconsistent(); ++i) {
assign(c, c[i]);
}
}
else {
for (unsigned i = 0; i <= bound; ++i) {
watch_literal(c, c[i]);
}
}
}
void card_extension::clear_watch(card& c) {
unsigned sz = std::min(c.k() + 1, c.size());
for (unsigned i = 0; i < sz; ++i) {
unwatch_literal(c[i], &c);
}
}
void card_extension::unwatch_literal(literal lit, card* c) {
if (m_var_infos.size() <= static_cast<unsigned>(lit.var())) {
return;
}
ptr_vector<card>* cards = m_var_infos[lit.var()].m_lit_watch[lit.sign()];
if (cards) {
remove(*cards, c);
}
}
void card_extension::remove(ptr_vector<card>& cards, card* c) {
for (unsigned j = 0; j < cards.size(); ++j) {
if (cards[j] == c) {
std::swap(cards[j], cards[cards.size()-1]);
cards.pop_back();
break;
}
}
}
void card_extension::assign(card& c, literal lit) {
if (value(lit) == l_true) {
return;
}
m_stats.m_num_propagations++;
//TRACE("sat", tout << "#prop: " << m_stats.m_num_propagations << " - " << c.lit() << " => " << lit << "\n";);
SASSERT(validate_unit_propagation(c));
s().assign(lit, justification::mk_ext_justification(c.index()));
}
void card_extension::watch_literal(card& c, literal lit) {
init_watch(lit.var());
ptr_vector<card>* cards = m_var_infos[lit.var()].m_lit_watch[lit.sign()];
if (cards == 0) {
cards = alloc(ptr_vector<card>);
m_var_infos[lit.var()].m_lit_watch[lit.sign()] = cards;
}
cards->push_back(&c);
}
void card_extension::set_conflict(card& c, literal lit) {
SASSERT(validate_conflict(c));
m_stats.m_num_conflicts++;
if (!resolve_conflict(c, lit)) {
literal_vector& lits = get_literals();
SASSERT(value(lit) == l_false);
SASSERT(value(c.lit()) == l_true);
lits.push_back(~c.lit());
lits.push_back(lit);
unsigned sz = c.size();
for (unsigned i = c.k(); i < sz; ++i) {
SASSERT(value(c[i]) == l_false);
lits.push_back(c[i]);
}
s().mk_clause_core(lits.size(), lits.c_ptr(), true);
}
SASSERT(s().inconsistent());
}
void card_extension::normalize_active_coeffs() {
while (!m_active_var_set.empty()) m_active_var_set.erase();
unsigned i = 0, j = 0, sz = m_active_vars.size();
for (; i < sz; ++i) {
bool_var v = m_active_vars[i];
if (!m_active_var_set.contains(v) && get_coeff(v) != 0) {
m_active_var_set.insert(v);
if (j != i) {
m_active_vars[j] = m_active_vars[i];
}
++j;
}
}
sz = j;
m_active_vars.shrink(sz);
}
void card_extension::inc_coeff(literal l, int offset) {
SASSERT(offset > 0);
bool_var v = l.var();
SASSERT(v != null_bool_var);
if (static_cast<bool_var>(m_coeffs.size()) <= v) {
m_coeffs.resize(v + 1, 0);
}
int coeff0 = m_coeffs[v];
if (coeff0 == 0) {
m_active_vars.push_back(v);
}
int inc = l.sign() ? -offset : offset;
int coeff1 = inc + coeff0;
m_coeffs[v] = coeff1;
if (coeff0 > 0 && inc < 0) {
m_bound -= coeff0 - std::max(0, coeff1);
}
else if (coeff0 < 0 && inc > 0) {
m_bound -= std::min(0, coeff1) - coeff0;
}
}
int card_extension::get_coeff(bool_var v) const {
return m_coeffs.get(v, 0);
}
int card_extension::get_abs_coeff(bool_var v) const {
int coeff = get_coeff(v);
if (coeff < 0) coeff = -coeff;
return coeff;
}
void card_extension::reset_coeffs() {
for (unsigned i = 0; i < m_active_vars.size(); ++i) {
m_coeffs[m_active_vars[i]] = 0;
}
m_active_vars.reset();
}
bool card_extension::resolve_conflict(card& c, literal alit) {
bool_var v;
m_conflict_lvl = 0;
for (unsigned i = 0; i < c.size(); ++i) {
literal lit = c[i];
SASSERT(value(lit) == l_false);
m_conflict_lvl = std::max(m_conflict_lvl, lvl(lit));
}
if (m_conflict_lvl < lvl(c.lit()) || m_conflict_lvl == 0) {
return false;
}
reset_coeffs();
m_num_marks = 0;
m_bound = c.k();
m_conflict.reset();
literal_vector const& lits = s().m_trail;
unsigned idx = lits.size()-1;
justification js;
literal consequent = ~alit;
process_card(c, 1);
DEBUG_CODE(active2pb(m_A););
while (m_num_marks > 0) {
SASSERT(value(consequent) == l_true);
v = consequent.var();
int offset = get_abs_coeff(v);
if (offset == 0) {
goto process_next_resolvent;
}
if (offset > 1000) {
goto bail_out;
}
SASSERT(validate_lemma());
SASSERT(offset > 0);
js = s().m_justification[v];
DEBUG_CODE(justification2pb(js, consequent, offset, m_B););
int bound = 1;
switch(js.get_kind()) {
case justification::NONE:
break;
case justification::BINARY:
inc_coeff(consequent, offset);
process_antecedent(~(js.get_literal()), offset);
break;
case justification::TERNARY:
inc_coeff(consequent, offset);
process_antecedent(~(js.get_literal1()), offset);
process_antecedent(~(js.get_literal2()), offset);
break;
case justification::CLAUSE: {
inc_coeff(consequent, offset);
clause & c = *(s().m_cls_allocator.get_clause(js.get_clause_offset()));
unsigned i = 0;
SASSERT(c[0] == consequent || c[1] == consequent);
if (c[0] == consequent) {
i = 1;
}
else {
process_antecedent(~c[0], offset);
i = 2;
}
unsigned sz = c.size();
for (; i < sz; i++)
process_antecedent(~c[i], offset);
break;
}
case justification::EXT_JUSTIFICATION: {
unsigned index = js.get_ext_justification_idx();
card& c2 = *m_constraints[index];
process_card(c2, offset);
bound = c2.k();
break;
}
default:
UNREACHABLE();
break;
}
m_bound += offset * bound;
DEBUG_CODE(
active2pb(m_C);
SASSERT(validate_resolvent());
m_A = m_C;);
// cut();
process_next_resolvent:
// find the next marked variable in the assignment stack
//
while (true) {
consequent = lits[idx];
v = consequent.var();
if (s().is_marked(v)) break;
SASSERT(idx > 0);
--idx;
}
SASSERT(lvl(v) == m_conflict_lvl);
s().reset_mark(v);
--idx;
--m_num_marks;
}
SASSERT(validate_lemma());
normalize_active_coeffs();
if (m_bound > 0 && m_active_vars.empty()) {
return false;
}
int slack = -m_bound;
for (unsigned i = 0; i < m_active_vars.size(); ++i) {
bool_var v = m_active_vars[i];
slack += get_abs_coeff(v);
}
alit = get_asserting_literal(~consequent);
slack -= get_abs_coeff(alit.var());
m_conflict.push_back(alit);
for (unsigned i = lits.size(); 0 <= slack && i > 0; ) {
--i;
literal lit = lits[i];
bool_var v = lit.var();
if (m_active_var_set.contains(v) && v != alit.var()) {
int coeff = get_coeff(v);
if (coeff < 0 && !lit.sign()) {
slack += coeff;
m_conflict.push_back(~lit);
}
else if (coeff > 0 && lit.sign()) {
slack -= coeff;
m_conflict.push_back(~lit);
}
}
}
SASSERT(slack < 0);
SASSERT(validate_conflict(m_conflict));
s().mk_clause_core(m_conflict.size(), m_conflict.c_ptr(), true);
return true;
bail_out:
while (m_num_marks > 0 && idx > 0) {
v = lits[idx].var();
if (s().is_marked(v)) {
s().reset_mark(v);
}
--idx;
}
return false;
}
void card_extension::process_card(card& c, int offset) {
SASSERT(c.k() <= c.size());
SASSERT(value(c.lit()) == l_true);
for (unsigned i = c.k(); i < c.size(); ++i) {
process_antecedent(c[i], offset);
}
for (unsigned i = 0; i < c.k(); ++i) {
inc_coeff(c[i], offset);
}
if (lvl(c.lit()) > 0) {
m_conflict.push_back(~c.lit());
}
}
void card_extension::process_antecedent(literal l, int offset) {
SASSERT(value(l) == l_false);
bool_var v = l.var();
unsigned level = lvl(v);
if (level > 0 && !s().is_marked(v) && level == m_conflict_lvl) {
s().mark(v);
++m_num_marks;
}
inc_coeff(l, offset);
}
literal card_extension::get_asserting_literal(literal p) {
if (get_abs_coeff(p.var()) != 0) {
return p;
}
unsigned level = 0;
for (unsigned i = 0; i < m_active_vars.size(); ++i) {
bool_var v = m_active_vars[i];
literal lit(v, get_coeff(v) < 0);
if (value(lit) == l_false && lvl(lit) > level) {
p = lit;
level = lvl(lit);
}
}
return p;
}
card_extension::card_extension(): m_solver(0) {}
card_extension::~card_extension() {
for (unsigned i = 0; i < m_var_infos.size(); ++i) {
m_var_infos[i].reset();
}
m_var_trail.reset();
m_var_lim.reset();
m_stats.reset();
}
void card_extension::add_at_least(bool_var v, literal_vector const& lits, unsigned k) {
unsigned index = m_constraints.size();
card* c = alloc(card, index, literal(v, false), lits, k);
m_constraints.push_back(c);
init_watch(v);
m_var_infos[v].m_card = c;
m_var_trail.push_back(v);
}
void card_extension::propagate(literal l, ext_constraint_idx idx, bool & keep) {
UNREACHABLE();
}
void card_extension::get_antecedents(literal l, ext_justification_idx idx, literal_vector & r) {
card& c = *m_constraints[idx];
DEBUG_CODE(
bool found = false;
for (unsigned i = 0; !found && i < c.k(); ++i) {
found = c[i] == l;
}
SASSERT(found););
r.push_back(c.lit());
SASSERT(value(c.lit()) == l_true);
for (unsigned i = c.k(); i < c.size(); ++i) {
SASSERT(value(c[i]) == l_false);
r.push_back(~c[i]);
}
}
lbool card_extension::add_assign(card& c, literal alit) {
// literal is assigned to false.
unsigned sz = c.size();
unsigned bound = c.k();
TRACE("sat", tout << "assign: " << c.lit() << " " << ~alit << " " << bound << "\n";);
SASSERT(0 < bound && bound < sz);
SASSERT(value(alit) == l_false);
SASSERT(value(c.lit()) == l_true);
unsigned index = 0;
for (index = 0; index <= bound; ++index) {
if (c[index] == alit) {
break;
}
}
if (index == bound + 1) {
// literal is no longer watched.
return l_undef;
}
SASSERT(index <= bound);
SASSERT(c[index] == alit);
// find a literal to swap with:
for (unsigned i = bound + 1; i < sz; ++i) {
literal lit2 = c[i];
if (value(lit2) != l_false) {
c.swap(index, i);
watch_literal(c, lit2);
return l_undef;
}
}
// conflict
if (bound != index && value(c[bound]) == l_false) {
TRACE("sat", tout << "conflict " << c[bound] << " " << alit << "\n";);
set_conflict(c, alit);
return l_false;
}
TRACE("sat", tout << "no swap " << index << " " << alit << "\n";);
// there are no literals to swap with,
// prepare for unit propagation by swapping the false literal into
// position bound. Then literals in positions 0..bound-1 have to be
// assigned l_true.
if (index != bound) {
c.swap(index, bound);
}
SASSERT(validate_unit_propagation(c));
for (unsigned i = 0; i < bound && !s().inconsistent(); ++i) {
assign(c, c[i]);
}
return s().inconsistent() ? l_false : l_true;
}
void card_extension::asserted(literal l) {
bool_var v = l.var();
ptr_vector<card>* cards = m_var_infos[v].m_lit_watch[!l.sign()];
if (cards != 0 && !cards->empty() && !s().inconsistent()) {
ptr_vector<card>::iterator it = cards->begin(), it2 = it, end = cards->end();
for (; it != end; ++it) {
card& c = *(*it);
if (value(c.lit()) != l_true) {
continue;
}
switch (add_assign(c, l)) {
case l_false: // conflict
for (; it != end; ++it, ++it2) {
*it2 = *it;
}
SASSERT(s().inconsistent());
cards->set_end(it2);
return;
case l_undef: // watch literal was swapped
break;
case l_true: // unit propagation, keep watching the literal
if (it2 != it) {
*it2 = *it;
}
++it2;
break;
}
}
cards->set_end(it2);
}
card* crd = m_var_infos[v].m_card;
if (crd != 0 && !s().inconsistent()) {
init_watch(*crd, !l.sign());
}
}
check_result card_extension::check() { return CR_DONE; }
void card_extension::push() {
m_var_lim.push_back(m_var_trail.size());
}
void card_extension::pop(unsigned n) {
unsigned new_lim = m_var_lim.size() - n;
unsigned sz = m_var_lim[new_lim];
while (m_var_trail.size() > sz) {
bool_var v = m_var_trail.back();
m_var_trail.pop_back();
if (v != null_bool_var) {
card* c = m_var_infos[v].m_card;
clear_watch(*c);
m_var_infos[v].m_card = 0;
dealloc(c);
}
}
m_var_lim.resize(new_lim);
}
void card_extension::simplify() {}
void card_extension::clauses_modifed() {}
lbool card_extension::get_phase(bool_var v) { return l_undef; }
void card_extension::display_watch(std::ostream& out, bool_var v, bool sign) const {
watch const* w = m_var_infos[v].m_lit_watch[sign];
if (w) {
watch const& wl = *w;
out << "watch: " << literal(v, sign) << " |-> ";
for (unsigned i = 0; i < wl.size(); ++i) {
out << wl[i]->lit() << " ";
}
out << "\n";
}
}
void card_extension::display(std::ostream& out, card& c, bool values) const {
out << c.lit();
if (c.lit() != null_literal) {
if (values) {
out << "@(" << value(c.lit());
if (value(c.lit()) != l_undef) {
out << ":" << lvl(c.lit());
}
out << ")";
}
out << c.lit() << "\n";
}
else {
out << " ";
}
for (unsigned i = 0; i < c.size(); ++i) {
literal l = c[i];
out << l;
if (values) {
out << "@(" << value(l);
if (value(l) != l_undef) {
out << ":" << lvl(l);
}
out << ") ";
}
}
out << " >= " << c.k() << "\n";
}
std::ostream& card_extension::display(std::ostream& out) const {
for (unsigned vi = 0; vi < m_var_infos.size(); ++vi) {
display_watch(out, vi, false);
display_watch(out, vi, true);
}
for (unsigned vi = 0; vi < m_var_infos.size(); ++vi) {
card* c = m_var_infos[vi].m_card;
if (c) {
display(out, *c, true);
}
}
return out;
}
void card_extension::collect_statistics(statistics& st) const {
st.update("card propagations", m_stats.m_num_propagations);
st.update("card conflicts", m_stats.m_num_conflicts);
}
bool card_extension::validate_conflict(card& c) {
if (!validate_unit_propagation(c)) return false;
for (unsigned i = 0; i < c.k(); ++i) {
if (value(c[i]) == l_false) return true;
}
return false;
}
bool card_extension::validate_unit_propagation(card const& c) {
if (value(c.lit()) != l_true) return false;
for (unsigned i = c.k(); i < c.size(); ++i) {
if (value(c[i]) != l_false) return false;
}
return true;
}
bool card_extension::validate_lemma() {
int val = -m_bound;
normalize_active_coeffs();
for (unsigned i = 0; i < m_active_vars.size(); ++i) {
bool_var v = m_active_vars[i];
int coeff = get_coeff(v);
literal lit(v, false);
SASSERT(coeff != 0);
if (coeff < 0 && value(lit) != l_true) {
val -= coeff;
}
else if (coeff > 0 && value(lit) != l_false) {
val += coeff;
}
}
return val < 0;
}
void card_extension::active2pb(ineq& p) {
normalize_active_coeffs();
p.reset(m_bound);
for (unsigned i = 0; i < m_active_vars.size(); ++i) {
bool_var v = m_active_vars[i];
literal lit(v, get_coeff(v) < 0);
p.m_lits.push_back(lit);
p.m_coeffs.push_back(get_abs_coeff(v));
}
}
void card_extension::justification2pb(justification const& js, literal lit, unsigned offset, ineq& p) {
switch (js.get_kind()) {
case justification::NONE:
p.reset(0);
break;
case justification::BINARY:
p.reset(offset);
p.push(lit, offset);
p.push(~js.get_literal(), offset);
break;
case justification::TERNARY:
p.reset(offset);
p.push(lit, offset);
p.push(~(js.get_literal1()), offset);
p.push(~(js.get_literal2()), offset);
break;
case justification::CLAUSE: {
p.reset(offset);
clause & c = *(s().m_cls_allocator.get_clause(js.get_clause_offset()));
unsigned sz = c.size();
for (unsigned i = 0; i < sz; i++)
p.push(~c[i], offset);
break;
}
case justification::EXT_JUSTIFICATION: {
unsigned index = js.get_ext_justification_idx();
card& c = *m_constraints[index];
p.reset(offset*c.k());
for (unsigned i = 0; i < c.size(); ++i) {
p.push(c[i], offset);
}
break;
}
default:
UNREACHABLE();
break;
}
}
// validate that m_A & m_B implies m_C
bool card_extension::validate_resolvent() {
u_map<unsigned> coeffs;
unsigned k = m_A.m_k + m_B.m_k;
for (unsigned i = 0; i < m_A.m_lits.size(); ++i) {
unsigned coeff = m_A.m_coeffs[i];
SASSERT(!coeffs.contains(m_A.m_lits[i].index()));
coeffs.insert(m_A.m_lits[i].index(), coeff);
}
for (unsigned i = 0; i < m_B.m_lits.size(); ++i) {
unsigned coeff1 = m_B.m_coeffs[i], coeff2;
literal lit = m_B.m_lits[i];
if (coeffs.find((~lit).index(), coeff2)) {
if (coeff1 == coeff2) {
coeffs.remove((~lit).index());
k += coeff1;
}
else if (coeff1 < coeff2) {
coeffs.insert((~lit).index(), coeff2 - coeff1);
k += coeff1;
}
else {
SASSERT(coeff2 < coeff1);
coeffs.remove((~lit).index());
coeffs.insert(lit.index(), coeff1 - coeff2);
k += coeff2;
}
}
else if (coeffs.find(lit.index(), coeff2)) {
coeffs.insert(lit.index(), coeff1 + coeff2);
}
else {
coeffs.insert(lit.index(), coeff1);
}
}
// C is above the sum of A and B
for (unsigned i = 0; i < m_C.m_lits.size(); ++i) {
literal lit = m_C.m_lits[i];
unsigned coeff;
if (coeffs.find(lit.index(), coeff)) {
SASSERT(coeff <= m_C.m_coeffs[i]);
coeffs.remove(lit.index());
}
}
SASSERT(coeffs.empty());
SASSERT(m_C.m_k <= k);
return true;
}
bool card_extension::validate_conflict(literal_vector const& lits) {
for (unsigned i = 0; i < lits.size(); ++i) {
if (value(lits[i]) != l_false) return false;
}
return true;
}
};

159
src/sat/card_extension.h Normal file
View file

@ -0,0 +1,159 @@
/*++
Copyright (c) 2017 Microsoft Corporation
Module Name:
card_extension.h
Abstract:
Cardinality extensions.
Author:
Nikolaj Bjorner (nbjorner) 2017-01-30
Revision History:
--*/
#ifndef CARD_EXTENSION_H_
#define CARD_EXTENSION_H_
#include"sat_extension.h"
#include"sat_solver.h"
namespace sat {
class card_extension : public extension {
struct stats {
unsigned m_num_propagations;
unsigned m_num_conflicts;
stats() { reset(); }
void reset() { memset(this, 0, sizeof(*this)); }
};
class card {
unsigned m_index;
literal m_lit;
unsigned m_k;
unsigned m_size;
literal_vector m_lits;
public:
card(unsigned index, literal lit, literal_vector const& lits, unsigned k);
unsigned index() const { return m_index; }
literal lit() const { return m_lit; }
literal operator[](unsigned i) const { return m_lits[i]; }
unsigned k() const { return m_k; }
unsigned size() const { return m_size; }
void swap(unsigned i, unsigned j) { std::swap(m_lits[i], m_lits[j]); }
void negate();
};
struct ineq {
literal_vector m_lits;
unsigned_vector m_coeffs;
unsigned m_k;
void reset(unsigned k) { m_lits.reset(); m_coeffs.reset(); m_k = k; }
void push(literal l, unsigned c) { m_lits.push_back(l); m_coeffs.push_back(c); }
};
typedef ptr_vector<card> watch;
struct var_info {
watch* m_lit_watch[2];
card* m_card;
var_info(): m_card(0) {
m_lit_watch[0] = 0;
m_lit_watch[1] = 0;
}
void reset() {
dealloc(m_card);
dealloc(m_lit_watch[0]);
dealloc(m_lit_watch[1]);
}
};
solver* m_solver;
stats m_stats;
ptr_vector<card> m_constraints;
// watch literals
svector<var_info> m_var_infos;
unsigned_vector m_var_trail;
unsigned_vector m_var_lim;
// conflict resolution
unsigned m_num_marks;
unsigned m_conflict_lvl;
svector<int> m_coeffs;
svector<bool_var> m_active_vars;
int m_bound;
tracked_uint_set m_active_var_set;
literal_vector m_conflict;
literal_vector m_literals;
solver& s() const { return *m_solver; }
void init_watch(card& c, bool is_true);
void init_watch(bool_var v);
void assign(card& c, literal lit);
lbool add_assign(card& c, literal lit);
void watch_literal(card& c, literal lit);
void set_conflict(card& c, literal lit);
void clear_watch(card& c);
void reset_coeffs();
inline lbool value(literal lit) const { return m_solver->value(lit); }
inline unsigned lvl(literal lit) const { return m_solver->lvl(lit); }
inline unsigned lvl(bool_var v) const { return m_solver->lvl(v); }
void unwatch_literal(literal w, card* c);
void remove(ptr_vector<card>& cards, card* c);
void normalize_active_coeffs();
void inc_coeff(literal l, int offset);
int get_coeff(bool_var v) const;
int get_abs_coeff(bool_var v) const;
literal_vector& get_literals() { m_literals.reset(); return m_literals; }
literal get_asserting_literal(literal conseq);
bool resolve_conflict(card& c, literal alit);
void process_antecedent(literal l, int offset);
void process_card(card& c, int offset);
void cut();
// validation utilities
bool validate_conflict(card& c);
bool validate_assign(literal_vector const& lits, literal lit);
bool validate_lemma();
bool validate_unit_propagation(card const& c);
bool validate_conflict(literal_vector const& lits);
ineq m_A, m_B, m_C;
void active2pb(ineq& p);
void justification2pb(justification const& j, literal lit, unsigned offset, ineq& p);
bool validate_resolvent();
void display(std::ostream& out, card& c, bool values) const;
void display_watch(std::ostream& out, bool_var v, bool sign) const;
public:
card_extension();
virtual ~card_extension();
void set_solver(solver* s) { m_solver = s; }
void add_at_least(bool_var v, literal_vector const& lits, unsigned k);
virtual void propagate(literal l, ext_constraint_idx idx, bool & keep);
virtual void get_antecedents(literal l, ext_justification_idx idx, literal_vector & r);
virtual void asserted(literal l);
virtual check_result check();
virtual void push();
virtual void pop(unsigned n);
virtual void simplify();
virtual void clauses_modifed();
virtual lbool get_phase(bool_var v);
virtual std::ostream& display(std::ostream& out) const;
virtual void collect_statistics(statistics& st) const;
};
};
#endif

1
src/sat/sat_config.cpp
View file

@ -77,6 +77,7 @@ namespace sat {
m_burst_search = p.burst_search();
m_max_conflicts = p.max_conflicts();
m_num_parallel = p.parallel_threads();
// These parameters are not exposed
m_simplify_mult1 = _p.get_uint("simplify_mult1", 300);

1
src/sat/sat_config.h
View file

@ -57,6 +57,7 @@ namespace sat {
unsigned m_random_seed;
unsigned m_burst_search;
unsigned m_max_conflicts;
unsigned m_num_parallel;
unsigned m_simplify_mult1;
double m_simplify_mult2;

4
src/sat/sat_extension.h
View file

@ -21,6 +21,7 @@ Revision History:
#include"sat_types.h"
#include"params.h"
#include"statistics.h"
namespace sat {
@ -30,6 +31,7 @@ namespace sat {
class extension {
public:
virtual ~extension() {}
virtual void propagate(literal l, ext_constraint_idx idx, bool & keep) = 0;
virtual void get_antecedents(literal l, ext_justification_idx idx, literal_vector & r) = 0;
virtual void asserted(literal l) = 0;
@ -39,6 +41,8 @@ namespace sat {
virtual void simplify() = 0;
virtual void clauses_modifed() = 0;
virtual lbool get_phase(bool_var v) = 0;
virtual std::ostream& display(std::ostream& out) const = 0;
virtual void collect_statistics(statistics& st) const = 0;
};
};

2
src/sat/sat_justification.h
View file

@ -33,7 +33,7 @@ namespace sat {
explicit justification(literal l):m_val1(l.to_uint()), m_val2(BINARY) {}
justification(literal l1, literal l2):m_val1(l1.to_uint()), m_val2(TERNARY + (l2.to_uint() << 3)) {}
explicit justification(clause_offset cls_off):m_val1(cls_off), m_val2(CLAUSE) {}
justification mk_ext_justification(ext_justification_idx idx) { return justification(idx, EXT_JUSTIFICATION); }
static justification mk_ext_justification(ext_justification_idx idx) { return justification(idx, EXT_JUSTIFICATION); }
kind get_kind() const { return static_cast<kind>(m_val2 & 7); }

59
src/sat/sat_mus.cpp
View file

@ -23,7 +23,7 @@ Notes:
namespace sat {
mus::mus(solver& s):s(s), m_is_active(false),m_restart(0), m_max_restarts(0) {}
mus::mus(solver& s):s(s), m_is_active(false), m_max_num_restarts(UINT_MAX) {}
mus::~mus() {}
@ -31,8 +31,6 @@ namespace sat {
m_core.reset();
m_mus.reset();
m_model.reset();
m_max_restarts = (s.m_stats.m_restart - m_restart) + 10;
m_restart = s.m_stats.m_restart;
}
void mus::set_core() {
@ -49,12 +47,12 @@ namespace sat {
}
lbool mus::operator()() {
m_max_num_restarts = s.m_config.m_core_minimize_partial ? s.num_restarts() + 10 : UINT_MAX;
flet<bool> _disable_min(s.m_config.m_core_minimize, false);
flet<bool> _is_active(m_is_active, true);
IF_VERBOSE(3, verbose_stream() << "(sat.mus " << s.get_core() << ")\n";);
IF_VERBOSE(3, verbose_stream() << "(sat.mus size: " << s.get_core().size() << " core: [" << s.get_core() << "])\n";);
reset();
lbool r = mus1();
m_restart = s.m_stats.m_restart;
return r;
}
@ -63,13 +61,13 @@ namespace sat {
TRACE("sat", tout << "old core: " << s.get_core() << "\n";);
literal_vector& core = get_core();
literal_vector& mus = m_mus;
if (core.size() > 64) {
if (!minimize_partial && core.size() > 64) {
return mus2();
}
unsigned delta_time = 0;
unsigned core_miss = 0;
while (!core.empty()) {
IF_VERBOSE(3, verbose_stream() << "(opt.mus reducing core: " << core.size() << " mus: " << mus.size() << ")\n";);
IF_VERBOSE(1, verbose_stream() << "(sat.mus num-to-process: " << core.size() << " mus: " << mus.size();
if (minimize_partial) verbose_stream() << " max-restarts: " << m_max_num_restarts;
verbose_stream() << ")\n";);
TRACE("sat",
tout << "core: " << core << "\n";
tout << "mus: " << mus << "\n";);
@ -78,34 +76,35 @@ namespace sat {
set_core();
return l_undef;
}
if (minimize_partial && 3*delta_time > core.size() && core.size() < mus.size()) {
break;
}
unsigned num_literals = core.size() + mus.size();
if (num_literals <= 2) {
// IF_VERBOSE(0, verbose_stream() << "num literals: " << core << " " << mus << "\n";);
break;
}
if (s.m_config.m_core_minimize_partial && s.m_stats.m_restart - m_restart > m_max_restarts) {
IF_VERBOSE(1, verbose_stream() << "(sat restart budget exceeded)\n";);
set_core();
return l_true;
}
literal lit = core.back();
core.pop_back();
lbool is_sat;
{
flet<unsigned> _restart_bound(s.m_config.m_restart_max, m_max_num_restarts);
scoped_append _sa(mus, core);
mus.push_back(~lit);
is_sat = s.check(mus.size(), mus.c_ptr());
TRACE("sat", tout << "mus: " << mus << "\n";);
}
IF_VERBOSE(1, verbose_stream() << "(sat.mus " << is_sat << ")\n";);
switch (is_sat) {
case l_undef:
core.push_back(lit);
set_core();
return l_undef;
if (!s.canceled()) {
// treat restart max as sat, so literal is in the mus
mus.push_back(lit);
}
else {
core.push_back(lit);
set_core();
return l_undef;
}
break;
case l_true: {
SASSERT(value_at(lit, s.get_model()) == l_false);
mus.push_back(lit);
@ -115,11 +114,9 @@ namespace sat {
case l_false:
literal_vector const& new_core = s.get_core();
if (new_core.contains(~lit)) {
IF_VERBOSE(3, verbose_stream() << "miss core " << lit << "\n";);
++core_miss;
IF_VERBOSE(3, verbose_stream() << "(sat.mus unit reduction, literal is in both cores " << lit << ")\n";);
}
else {
core_miss = 0;
TRACE("sat", tout << "core: " << new_core << " mus: " << mus << "\n";);
core.reset();
for (unsigned i = 0; i < new_core.size(); ++i) {
@ -131,14 +128,6 @@ namespace sat {
}
break;
}
unsigned new_num_literals = core.size() + mus.size();
if (new_num_literals == num_literals) {
delta_time++;
}
else {
delta_time = 0;
}
}
set_core();
IF_VERBOSE(3, verbose_stream() << "(sat.mus.new " << s.m_core << ")\n";);
@ -159,13 +148,9 @@ namespace sat {
lbool mus::qx(literal_set& assignment, literal_set& support, bool has_support) {
lbool is_sat = l_true;
if (s.m_config.m_core_minimize_partial && s.m_stats.m_restart - m_restart > m_max_restarts) {
IF_VERBOSE(1, verbose_stream() << "(sat restart budget exceeded)\n";);
return l_true;
}
if (has_support) {
scoped_append _sa(m_mus, support.to_vector());
is_sat = s.check(m_mus.size(), m_mus.c_ptr());
is_sat = s.check(m_mus.size(), m_mus.c_ptr());
switch (is_sat) {
case l_false: {
literal_set core(s.get_core());
@ -173,7 +158,7 @@ namespace sat {
assignment.reset();
return l_true;
}
case l_undef:
case l_undef:
return l_undef;
case l_true:
update_model();

3
src/sat/sat_mus.h
View file

@ -26,8 +26,7 @@ namespace sat {
literal_vector m_mus;
bool m_is_active;
model m_model; // model obtained during minimal unsat core
unsigned m_restart;
unsigned m_max_restarts;
unsigned m_max_num_restarts;
public:

45
src/sat/sat_par.cpp Normal file
View file

@ -0,0 +1,45 @@
/*++
Copyright (c) 2017 Microsoft Corporation
Module Name:
sat_par.cpp
Abstract:
Utilities for parallel SAT solving.
Author:
Nikolaj Bjorner (nbjorner) 2017-1-29.
Revision History:
--*/
#include "sat_par.h"
namespace sat {
par::par() {}
void par::exchange(literal_vector const& in, unsigned& limit, literal_vector& out) {
#pragma omp critical (par_solver)
{
if (limit < m_units.size()) {
// this might repeat some literals.
out.append(m_units.size() - limit, m_units.c_ptr() + limit);
}
for (unsigned i = 0; i < in.size(); ++i) {
literal lit = in[i];
if (!m_unit_set.contains(lit.index())) {
m_unit_set.insert(lit.index());
m_units.push_back(lit);
}
}
limit = m_units.size();
}
}
};

39
src/sat/sat_par.h Normal file
View file

@ -0,0 +1,39 @@
/*++
Copyright (c) 2017 Microsoft Corporation
Module Name:
sat_par.h
Abstract:
Utilities for parallel SAT solving.
Author:
Nikolaj Bjorner (nbjorner) 2017-1-29.
Revision History:
--*/
#ifndef SAT_PAR_H_
#define SAT_PAR_H_
#include"sat_types.h"
#include"hashtable.h"
#include"map.h"
namespace sat {
class par {
typedef hashtable<unsigned, u_hash, u_eq> index_set;
literal_vector m_units;
index_set m_unit_set;
public:
par();
void exchange(literal_vector const& in, unsigned& limit, literal_vector& out);
};
};
#endif

1
src/sat/sat_params.pyg
View file

@ -22,4 +22,5 @@ def_module_params('sat',
('dyn_sub_res', BOOL, True, 'dynamic subsumption resolution for minimizing learned clauses'),
('core.minimize', BOOL, False, 'minimize computed core'),
('core.minimize_partial', BOOL, False, 'apply partial (cheap) core minimization'),
('parallel_threads', UINT, 1, 'number of parallel threads to use'),
('dimacs.core', BOOL, False, 'extract core from DIMACS benchmarks')))

25
src/sat/sat_simplifier.cpp
View file

@ -896,7 +896,7 @@ namespace sat {
unsigned idx = l.index();
if (m_queue.contains(idx))
m_queue.decreased(idx);
else
else
m_queue.insert(idx);
}
literal next() { SASSERT(!empty()); return to_literal(m_queue.erase_min()); }
@ -918,16 +918,19 @@ namespace sat {
}
void insert(literal l) {
bool_var v = l.var();
if (s.is_external(v) || s.was_eliminated(v))
return;
m_queue.insert(l);
}
bool process_var(bool_var v) {
return !s.is_external(v) && !s.was_eliminated(v);
}
void operator()(unsigned num_vars) {
for (bool_var v = 0; v < num_vars; v++) {
insert(literal(v, false));
insert(literal(v, true));
if (process_var(v)) {
insert(literal(v, false));
insert(literal(v, true));
}
}
while (!m_queue.empty()) {
s.checkpoint();
@ -941,9 +944,9 @@ namespace sat {
void process(literal l) {
TRACE("blocked_clause", tout << "processing: " << l << "\n";);
model_converter::entry * new_entry = 0;
if (s.is_external(l.var()) || s.was_eliminated(l.var()))
if (!process_var(l.var())) {
return;
}
{
m_to_remove.reset();
{
@ -963,8 +966,10 @@ namespace sat {
mc.insert(*new_entry, c);
unsigned sz = c.size();
for (unsigned i = 0; i < sz; i++) {
if (c[i] != l)
m_queue.decreased(~c[i]);
literal lit = c[i];
if (lit != l && process_var(lit.var())) {
m_queue.decreased(~lit);
}
}
}
s.unmark_all(c);

150
src/sat/sat_solver.cpp
View file

@ -35,6 +35,7 @@ namespace sat {
m_rlimit(l),
m_config(p),
m_ext(ext),
m_par(0),
m_cleaner(*this),
m_simplifier(*this, p),
m_scc(*this, p),
@ -72,6 +73,8 @@ namespace sat {
void solver::copy(solver const & src) {
SASSERT(m_mc.empty() && src.m_mc.empty());
SASSERT(scope_lvl() == 0);
SASSERT(src.scope_lvl() == 0);
// create new vars
if (num_vars() < src.num_vars()) {
for (bool_var v = num_vars(); v < src.num_vars(); v++) {
@ -81,19 +84,25 @@ namespace sat {
VERIFY(v == mk_var(ext, dvar));
}
}
unsigned sz = src.scope_lvl() == 0 ? src.m_trail.size() : src.m_scopes[0].m_trail_lim;
for (unsigned i = 0; i < sz; ++i) {
assign(src.m_trail[i], justification());
}
{
// copy binary clauses
vector<watch_list>::const_iterator it = src.m_watches.begin();
vector<watch_list>::const_iterator end = src.m_watches.begin();
for (unsigned l_idx = 0; it != end; ++it, ++l_idx) {
watch_list const & wlist = *it;
unsigned sz = src.m_watches.size();
for (unsigned l_idx = 0; l_idx < sz; ++l_idx) {
literal l = ~to_literal(l_idx);
watch_list::const_iterator it2 = wlist.begin();
watch_list::const_iterator end2 = wlist.end();
for (; it2 != end2; ++it2) {
if (!it2->is_binary_non_learned_clause())
watch_list const & wlist = src.m_watches[l_idx];
watch_list::const_iterator it = wlist.begin();
watch_list::const_iterator end = wlist.end();
for (; it != end; ++it) {
if (!it->is_binary_non_learned_clause())
continue;
literal l2 = it->get_literal();
if (l.index() > l2.index())
continue;
literal l2 = it2->get_literal();
mk_clause_core(l, l2);
}
}
@ -711,6 +720,9 @@ namespace sat {
pop_to_base_level();
IF_VERBOSE(2, verbose_stream() << "(sat.sat-solver)\n";);
SASSERT(scope_lvl() == 0);
if (m_config.m_num_parallel > 0 && !m_par) {
return check_par(num_lits, lits);
}
#ifdef CLONE_BEFORE_SOLVING
if (m_mc.empty()) {
m_clone = alloc(solver, m_params, 0 /* do not clone extension */);
@ -759,6 +771,7 @@ namespace sat {
restart();
simplify_problem();
exchange_par();
if (check_inconsistent()) return l_false;
gc();
@ -774,6 +787,121 @@ namespace sat {
}
}
enum par_exception_kind {
DEFAULT_EX,
ERROR_EX
};
lbool solver::check_par(unsigned num_lits, literal const* lits) {
int num_threads = static_cast<int>(m_config.m_num_parallel);
scoped_limits scoped_rlimit(rlimit());
vector<reslimit> rlims(num_threads);
ptr_vector<sat::solver> solvers(num_threads);
sat::par par;
for (int i = 0; i < num_threads; ++i) {
m_params.set_uint("random_seed", i);
solvers[i] = alloc(sat::solver, m_params, rlims[i], 0);
solvers[i]->copy(*this);
solvers[i]->set_par(&par);
scoped_rlimit.push_child(&solvers[i]->rlimit());
}
int finished_id = -1;
std::string ex_msg;
par_exception_kind ex_kind;
unsigned error_code = 0;
lbool result = l_undef;
#pragma omp parallel for
for (int i = 0; i < num_threads; ++i) {
try {
lbool r = solvers[i]->check(num_lits, lits);
bool first = false;
#pragma omp critical (par_solver)
{
if (finished_id == UINT_MAX) {
finished_id = i;
first = true;
result = r;
}
}
if (first) {
if (r == l_true) {
set_model(solvers[i]->get_model());
}
else if (r == l_false) {
m_core.reset();
m_core.append(solvers[i]->get_core());
}
for (int j = 0; j < num_threads; ++j) {
if (i != j) {
rlims[j].cancel();
}
}
}
}
catch (z3_error & err) {
if (i == 0) {
error_code = err.error_code();
ex_kind = ERROR_EX;
}
}
catch (z3_exception & ex) {
if (i == 0) {
ex_msg = ex.msg();
ex_kind = DEFAULT_EX;
}
}
}
for (int i = 0; i < num_threads; ++i) {
dealloc(solvers[i]);
}
if (finished_id == -1) {
switch (ex_kind) {
case ERROR_EX: throw z3_error(error_code);
default: throw default_exception(ex_msg.c_str());
}
}
return result;
}
/*
\brief import lemmas/units from parallel sat solvers.
*/
void solver::exchange_par() {
if (m_par && scope_lvl() == 0) {
unsigned num_in = 0, num_out = 0;
SASSERT(scope_lvl() == 0); // parallel with assumptions is TBD
literal_vector in, out;
for (unsigned i = m_par_limit_out; i < m_trail.size(); ++i) {
literal lit = m_trail[i];
if (lit.var() < m_par_num_vars) {
++num_out;
out.push_back(lit);
}
}
m_par_limit_out = m_trail.size();
m_par->exchange(out, m_par_limit_in, in);
for (unsigned i = 0; !inconsistent() && i < in.size(); ++i) {
literal lit = in[i];
SASSERT(lit.var() < m_par_num_vars);
if (lvl(lit.var()) != 0 || value(lit) != l_true) {
++num_in;
assign(lit, justification());
}
}
if (num_in > 0 || num_out > 0) {
IF_VERBOSE(1, verbose_stream() << "(sat-sync out: " << num_out << " in: " << num_in << ")\n";);
}
}
}
void solver::set_par(par* p) {
m_par = p;
m_par_num_vars = num_vars();
m_par_limit_in = 0;
m_par_limit_out = 0;
}
bool_var solver::next_var() {
bool_var next;
@ -2624,6 +2752,7 @@ namespace sat {
m_scc.collect_statistics(st);
m_asymm_branch.collect_statistics(st);
m_probing.collect_statistics(st);
if (m_ext) m_ext->collect_statistics(st);
}
void solver::reset_statistics() {
@ -2728,6 +2857,9 @@ namespace sat {
display_units(out);
display_binary(out);
out << m_clauses << m_learned;
if (m_ext) {
m_ext->display(out);
}
out << ")\n";
}

12
src/sat/sat_solver.h
View file

@ -33,6 +33,7 @@ Revision History:
#include"sat_iff3_finder.h"
#include"sat_probing.h"
#include"sat_mus.h"
#include"sat_par.h"
#include"params.h"
#include"statistics.h"
#include"stopwatch.h"
@ -74,6 +75,7 @@ namespace sat {
config m_config;
stats m_stats;
extension * m_ext;
par* m_par;
random_gen m_rand;
clause_allocator m_cls_allocator;
cleaner m_cleaner;
@ -128,6 +130,10 @@ namespace sat {
literal_set m_assumption_set; // set of enabled assumptions
literal_vector m_core; // unsat core
unsigned m_par_limit_in;
unsigned m_par_limit_out;
unsigned m_par_num_vars;
void del_clauses(clause * const * begin, clause * const * end);
friend class integrity_checker;
@ -139,6 +145,7 @@ namespace sat {
friend class probing;
friend class iff3_finder;
friend class mus;
friend class card_extension;
friend struct mk_stat;
public:
solver(params_ref const & p, reslimit& l, extension * ext);
@ -209,6 +216,7 @@ namespace sat {
bool inconsistent() const { return m_inconsistent; }
unsigned num_vars() const { return m_level.size(); }
unsigned num_clauses() const;
unsigned num_restarts() const { return m_restarts; }
bool is_external(bool_var v) const { return m_external[v] != 0; }
bool was_eliminated(bool_var v) const { return m_eliminated[v] != 0; }
unsigned scope_lvl() const { return m_scope_lvl; }
@ -240,7 +248,9 @@ namespace sat {
m_num_checkpoints = 0;
if (memory::get_allocation_size() > m_config.m_max_memory) throw solver_exception(Z3_MAX_MEMORY_MSG);
}
void set_par(par* p);
bool canceled() { return !m_rlimit.inc(); }
config const& get_config() { return m_config; }
typedef std::pair<literal, literal> bin_clause;
protected:
watch_list & get_wlist(literal l) { return m_watches[l.index()]; }
@ -316,6 +326,8 @@ namespace sat {
bool check_model(model const & m) const;
void restart();
void sort_watch_lits();
void exchange_par();
lbool check_par(unsigned num_lits, literal const* lits);
// -----------------------
//

3
src/sat/sat_solver/inc_sat_solver.cpp
View file

@ -140,6 +140,7 @@ public:
if (r != l_true) return r;
r = m_solver.check(m_asms.size(), m_asms.c_ptr());
switch (r) {
case l_true:
if (sz > 0) {
@ -276,6 +277,8 @@ public:
return r;
}
virtual lbool find_mutexes(expr_ref_vector const& vars, vector<expr_ref_vector>& mutexes) {
sat::literal_vector ls;
u_map<expr*> lit2var;

3
src/smt/params/smt_params_helper.pyg
View file

@ -63,5 +63,6 @@ def_module_params(module_name='smt',
('dack.threshold', UINT, 10, ' number of times the congruence rule must be used before Leibniz\'s axiom is expanded'),
('core.validate', BOOL, False, 'validate unsat core produced by SMT context'),
('core.minimize', BOOL, False, 'minimize unsat core produced by SMT context'),
('core.extend_patterns', BOOL, False, 'extend unsat core with literals that trigger (potential) quantifier instances')
('core.extend_patterns', BOOL, False, 'extend unsat core with literals that trigger (potential) quantifier instances'),
('core.extend_patterns.max_distance', UINT, UINT_MAX, 'limits the distance of a pattern-extended unsat core')
))

2
src/smt/smt_context.cpp
View file

@ -2040,11 +2040,13 @@ namespace smt {
v.shrink(old_size);
}
#if 0
void context::mark_as_deleted(clause * cls) {
SASSERT(!cls->deleted());
remove_cls_occs(cls);
cls->mark_as_deleted(m_manager);
}
#endif
/**
\brief Undo variable assignments.

14
src/smt/smt_solver.cpp
View file

@ -37,6 +37,7 @@ namespace smt {
symbol m_logic;
bool m_minimizing_core;
bool m_core_extend_patterns;
unsigned m_core_extend_patterns_max_distance;
obj_map<expr, expr*> m_name2assertion;
public:
@ -46,12 +47,14 @@ namespace smt {
m_params(p),
m_context(m, m_smt_params),
m_minimizing_core(false),
m_core_extend_patterns(false) {
m_core_extend_patterns(false),
m_core_extend_patterns_max_distance(UINT_MAX) {
m_logic = l;
if (m_logic != symbol::null)
m_context.set_logic(m_logic);
smt_params_helper smth(p);
m_core_extend_patterns = smth.core_extend_patterns();
m_core_extend_patterns_max_distance = smth.core_extend_patterns_max_distance();
}
virtual solver * translate(ast_manager & m, params_ref const & p) {
@ -119,7 +122,8 @@ namespace smt {
SASSERT(n <= lvl);
unsigned new_lvl = lvl - n;
unsigned old_sz = m_scopes[new_lvl];
for (unsigned i = cur_sz - 1; i >= old_sz; i--) {
for (unsigned i = cur_sz; i > old_sz; ) {
--i;
expr * key = m_assumptions[i].get();
SASSERT(m_name2assertion.contains(key));
expr * value = m_name2assertion.find(key);
@ -283,7 +287,7 @@ namespace smt {
func_decl_set pattern_fds;
vector<func_decl_set> assrtn_fds;
do {
for (unsigned d = 0; d < m_core_extend_patterns_max_distance; d++) {
new_core_literals.reset();
unsigned sz = core.size();
@ -308,8 +312,10 @@ namespace smt {
}
core.append(new_core_literals.size(), new_core_literals.c_ptr());
if (new_core_literals.empty())
break;
}
while (!new_core_literals.empty());
}
};
};

11
src/smt/theory_pb.h
View file

@ -250,16 +250,6 @@ namespace smt {
typedef map<arg_t, bool_var, arg_t::hash, arg_t::eq> arg_map;
struct row_info {
unsigned m_slack; // slack variable in simplex tableau
numeral m_bound; // bound
arg_t m_rep; // representative
row_info(theory_var slack, numeral const& b, arg_t const& r):
m_slack(slack), m_bound(b), m_rep(r) {}
row_info(): m_slack(0) {}
};
struct var_info {
ineq_watch* m_lit_watch[2];
ineq_watch* m_var_watch;
@ -290,7 +280,6 @@ namespace smt {
theory_pb_params m_params;
svector<var_info> m_var_infos;
unsynch_mpq_inf_manager m_mpq_inf_mgr; // Simplex: manage inf_mpq numerals
mutable unsynch_mpz_manager m_mpz_mgr; // Simplex: manager mpz numerals
unsigned_vector m_ineqs_trail;
unsigned_vector m_ineqs_lim;

41
src/smt/theory_seq.cpp
View file

@ -2940,8 +2940,8 @@ void theory_seq::deque_axiom(expr* n) {
encode that s is not contained in of xs1
where s1 is all of s, except the last element.
lit or s = "" or s = s1*(unit c)
lit or s = "" or !contains(x*s1, s)
s = "" or s = s1*(unit c)
s = "" or !contains(x*s1, s)
*/
void theory_seq::tightest_prefix(expr* s, expr* x) {
expr_ref s1 = mk_first(s);
@ -2958,22 +2958,19 @@ void theory_seq::tightest_prefix(expr* s, expr* x) {
let i = Index(t, s, offset):
offset >= len(t) => i = -1
offset fixed to 0:
len(t) != 0 & !contains(t, s) => i = -1
len(t) != 0 & contains(t, s) => t = xsy & i = len(x)
offset = 0 & len(t) != 0 & contains(t, s) => t = xsy & i = len(x)
tightest_prefix(x, s)
offset not fixed:
0 <= offset < len(t) => xy = t &
len(x) = offset &
(-1 = indexof(y, s, 0) => -1 = i) &
(indexof(y, s, 0) >= 0 => indexof(t, s, 0) + offset = i)
if offset < 0
under specified
offset < 0 => i = -1
optional lemmas:
(len(s) > len(t) -> i = -1)
@ -2987,17 +2984,19 @@ void theory_seq::add_indexof_axiom(expr* i) {
expr_ref minus_one(m_autil.mk_int(-1), m);
expr_ref zero(m_autil.mk_int(0), m);
expr_ref xsy(m);
literal cnt = mk_literal(m_util.str.mk_contains(t, s));
literal i_eq_m1 = mk_eq(i, minus_one, false);
add_axiom(cnt, i_eq_m1);
literal s_eq_empty = mk_eq_empty(s);
add_axiom(~s_eq_empty, mk_eq(i, zero, false));
add_axiom(s_eq_empty, ~mk_eq_empty(t), i_eq_m1);
if (!offset || (m_autil.is_numeral(offset, r) && r.is_zero())) {
expr_ref x = mk_skolem(m_indexof_left, t, s);
expr_ref y = mk_skolem(m_indexof_right, t, s);
xsy = mk_concat(x, s, y);
expr_ref lenx(m_util.str.mk_length(x), m);
literal cnt = mk_literal(m_util.str.mk_contains(t, s));
literal s_eq_empty = mk_eq_empty(s);
add_axiom(cnt, mk_eq(i, minus_one, false));
add_axiom(~s_eq_empty, mk_eq(i, zero, false));
add_axiom(s_eq_empty, ~mk_eq_empty(t), mk_eq(i, minus_one, false));
add_axiom(~cnt, s_eq_empty, mk_seq_eq(t, xsy));
add_axiom(~cnt, s_eq_empty, mk_eq(i, lenx, false));
tightest_prefix(s, x);
@ -3024,10 +3023,13 @@ void theory_seq::add_indexof_axiom(expr* i) {
add_axiom(~offset_ge_0, offset_ge_len, mk_seq_eq(t, mk_concat(x, y)));
add_axiom(~offset_ge_0, offset_ge_len, mk_eq(m_util.str.mk_length(x), offset, false));
add_axiom(~offset_ge_0, offset_ge_len,
~mk_eq(indexof0, minus_one, false), mk_eq(i, minus_one, false));
~mk_eq(indexof0, minus_one, false), i_eq_m1);
add_axiom(~offset_ge_0, offset_ge_len,
~mk_literal(m_autil.mk_ge(indexof0, zero)),
mk_eq(offset_p_indexof0, i, false));
// offset < 0 => -1 = i
add_axiom(offset_ge_0, i_eq_m1);
}
}
@ -3817,6 +3819,15 @@ void theory_seq::new_eq_eh(dependency* deps, enode* n1, enode* n2) {
solve_eqs(m_eqs.size()-1);
enforce_length_coherence(n1, n2);
}
else if (n1 != n2 && m_util.is_re(n1->get_owner())) {
warning_msg("equality between regular expressions is not yet supported");
eautomaton* a1 = get_automaton(n1->get_owner());
eautomaton* a2 = get_automaton(n2->get_owner());
// eautomaton* b1 = mk_difference(*a1, *a2);
// eautomaton* b2 = mk_difference(*a2, *a1);
// eautomaton* c = mk_union(*b1, *b2);
// then some emptiness check.
}
}
void theory_seq::new_diseq_eh(theory_var v1, theory_var v2) {

7
src/tactic/tactical.cpp
View file

@ -461,13 +461,6 @@ enum par_exception_kind {
class par_tactical : public or_else_tactical {
struct scoped_limits {
reslimit& m_limit;
unsigned m_sz;
scoped_limits(reslimit& lim): m_limit(lim), m_sz(0) {}
~scoped_limits() { for (unsigned i = 0; i < m_sz; ++i) m_limit.pop_child(); }
void push_child(reslimit* lim) { m_limit.push_child(lim); ++m_sz; }
};
public:
par_tactical(unsigned num, tactic * const * ts):or_else_tactical(num, ts) {}

9
src/util/rlimit.h
View file

@ -61,4 +61,13 @@ public:
};
struct scoped_limits {
reslimit& m_limit;
unsigned m_sz;
scoped_limits(reslimit& lim): m_limit(lim), m_sz(0) {}
~scoped_limits() { for (unsigned i = 0; i < m_sz; ++i) m_limit.pop_child(); }
void push_child(reslimit* lim) { m_limit.push_child(lim); ++m_sz; }
};
#endif