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fix at-most-1 constraint compiler bug

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2016-10-22 18:50:16 -07:00
parent bb6d826908
commit 23b9d3ef55
17 changed files with 369 additions and 62 deletions
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31
src/api/api_opt.cpp
View file

@ -27,6 +27,7 @@ Revision History:
#include"cancel_eh.h"
#include"scoped_timer.h"
#include"smt2parser.h"
#include"api_ast_vector.h"
extern "C" {
@ -296,6 +297,36 @@ extern "C" {
}
Z3_ast_vector Z3_API Z3_optimize_get_assertions(Z3_context c, Z3_optimize o) {
Z3_TRY;
LOG_Z3_optimize_get_assertions(c, o);
RESET_ERROR_CODE();
Z3_ast_vector_ref * v = alloc(Z3_ast_vector_ref, *mk_c(c), mk_c(c)->m());
mk_c(c)->save_object(v);
expr_ref_vector hard(mk_c(c)->m());
to_optimize_ptr(o)->get_hard_constraints(hard);
for (unsigned i = 0; i < hard.size(); i++) {
v->m_ast_vector.push_back(hard[i].get());
}
RETURN_Z3(of_ast_vector(v));
Z3_CATCH_RETURN(0);
}
unsigned Z3_API Z3_optimize_get_num_objectives(Z3_context c, Z3_optimize o) {
RESET_ERROR_CODE();
return to_optimize_ptr(o)->num_objectives();
}
Z3_ast Z3_API Z3_optimize_get_objective(Z3_context c, Z3_optimize o, unsigned index) {
Z3_TRY;
LOG_Z3_optimize_get_objective(c, o, index);
RESET_ERROR_CODE();
expr_ref result = to_optimize_ptr(o)->get_objective(index);
mk_c(c)->save_ast_trail(result);
RETURN_Z3(of_expr(result));
Z3_CATCH_RETURN(0);
}
};

9
src/api/python/z3/z3.py
View file

@ -6796,6 +6796,15 @@ class Optimize(Z3PPObject):
"""Parse assertions and objectives from a string"""
Z3_optimize_from_string(self.ctx.ref(), self.optimize, s)
def assertions(self):
"""Return an AST vector containing all added constraints."""
return AstVector(Z3_optimize_get_assertions(self.ctx.ref(), self.optimize), self.ctx)
def objectives(self):
"""returns set of objective functions"""
num = Z3_optimize_get_num_objectives(self.ctx.ref(), self.optimize)
return [_to_expr_ref(Z3_optimize_get_objective(self.ctx.ref(), self.optimize, i), self.ctx) for i in range(num)]
def __repr__(self):
"""Return a formatted string with all added rules and constraints."""
return self.sexpr()

2
src/api/z3_api.h
View file

@ -5832,7 +5832,7 @@ extern "C" {
void Z3_API Z3_solver_assert_and_track(Z3_context c, Z3_solver s, Z3_ast a, Z3_ast p);
/**
\brief Return the set of asserted formulas as a goal object.
\brief Return the set of asserted formulas on the solver.
def_API('Z3_solver_get_assertions', AST_VECTOR, (_in(CONTEXT), _in(SOLVER)))
*/

27
src/api/z3_optimization.h
View file

@ -239,6 +239,33 @@ extern "C" {
def_API('Z3_optimize_get_statistics', STATS, (_in(CONTEXT), _in(OPTIMIZE)))
*/
Z3_stats Z3_API Z3_optimize_get_statistics(Z3_context c, Z3_optimize d);
/**
\brief Return the set of asserted formulas on the optimization context.
def_API('Z3_optimize_get_assertions', AST_VECTOR, (_in(CONTEXT), _in(OPTIMIZE)))
*/
Z3_ast_vector Z3_API Z3_optimize_get_assertions(Z3_context c, Z3_optimize o);
/**
\brief Return number of objectives on the optimization context.
def_API('Z3_optimize_get_num_objectives', UINT, (_in(CONTEXT), _in(OPTIMIZE)))
*/
unsigned Z3_API Z3_optimize_get_num_objectives(Z3_context c, Z3_optimize o);
/**
\brief Return i'th objective function. If the objective function is a max-sat objective it is returned
as a Pseudo-Boolean (minimization) sum of the form (+ (if f1 w1 0) (if f2 w2 0) ...)
If the objective function is entered as a maximization objective, then return the corresponding minimizaiton
objective. In this way the resulting objective function is always returned as a minimization objective.
def_API('Z3_optimize_get_objective', AST, (_in(CONTEXT), _in(OPTIMIZE), _in(UINT)))
*/
Z3_ast Z3_API Z3_optimize_get_objective(Z3_context c, Z3_optimize o, unsigned index);
/*@}*/
/*@}*/

43
src/ast/rewriter/arith_rewriter.cpp
View file

@ -162,8 +162,8 @@ bool arith_rewriter::div_polynomial(expr * t, numeral const & g, const_treatment
}
bool arith_rewriter::is_bound(expr * arg1, expr * arg2, op_kind kind, expr_ref & result) {
numeral c;
if (!is_add(arg1) && is_numeral(arg2, c)) {
numeral b, c;
if (!is_add(arg1) && !m_util.is_mod(arg1) && is_numeral(arg2, c)) {
numeral a;
bool r = false;
expr * pp = get_power_product(arg1, a);
@ -193,6 +193,45 @@ bool arith_rewriter::is_bound(expr * arg1, expr * arg2, op_kind kind, expr_ref &
case EQ: result = m_util.mk_eq(pp, k); return true;
}
}
expr* t1, *t2;
bool is_int;
if (m_util.is_mod(arg2)) {
std::swap(arg1, arg2);
switch (kind) {
case LE: kind = GE; break;
case GE: kind = LE; break;
case EQ: break;
}
}
if (m_util.is_numeral(arg2, c, is_int) && is_int &&
m_util.is_mod(arg1, t1, t2) && m_util.is_numeral(t2, b, is_int) && !b.is_zero()) {
// mod x b <= c = false if c < 0, b != 0, true if c >= b, b != 0
if (c.is_neg()) {
switch (kind) {
case EQ:
case LE: result = m().mk_false(); return true;
case GE: result = m().mk_true(); return true;
}
}
if (c.is_zero() && kind == GE) {
result = m().mk_true();
return true;
}
if (c.is_pos() && c >= abs(b)) {
switch (kind) {
case LE: result = m().mk_true(); return true;
case EQ:
case GE: result = m().mk_false(); return true;
}
}
// mod x b <= b - 1
if (c + rational::one() == abs(b) && kind == LE) {
result = m().mk_true();
return true;
}
}
return false;
}

11
src/opt/maxres.cpp
View file

@ -297,12 +297,16 @@ public:
sort_assumptions(mutex);
ptr_vector<expr> core(mutex.size(), mutex.c_ptr());
remove_soft(core, m_asms);
rational weight(0);
rational weight(0), sum1(0), sum2(0);
for (unsigned i = 0; i < mutex.size(); ++i) {
sum1 += get_weight(mutex[i].get());
}
while (!mutex.empty()) {
expr_ref soft = mk_or(mutex);
rational w = get_weight(mutex.back());
weight = w - weight;
m_lower += weight*rational(mutex.size()-1);
sum2 += weight*rational(mutex.size());
add_soft(soft, weight);
mutex.pop_back();
while (!mutex.empty() && get_weight(mutex.back()) == w) {
@ -310,6 +314,7 @@ public:
}
weight = w;
}
SASSERT(sum1 == sum2);
}
lbool check_sat_hill_climb(expr_ref_vector& asms1) {
@ -398,7 +403,7 @@ public:
while (is_sat == l_false) {
core.reset();
s().get_unsat_core(core);
//verify_core(core);
// verify_core(core);
model_ref mdl;
get_mus_model(mdl);
is_sat = minimize_core(core);
@ -772,8 +777,6 @@ public:
for (unsigned i = 0; i < m_soft.size(); ++i) {
m_assignment[i] = is_true(m_soft[i]);
}
DEBUG_CODE(verify_assignment(););

79
src/opt/opt_context.cpp
View file

@ -181,6 +181,43 @@ namespace opt {
clear_state();
}
void context::get_hard_constraints(expr_ref_vector& hard) {
hard.append(m_scoped_state.m_hard);
}
expr_ref context::get_objective(unsigned i) {
SASSERT(i < num_objectives());
objective const& o = m_scoped_state.m_objectives[i];
expr_ref result(m), zero(m);
expr_ref_vector args(m);
switch (o.m_type) {
case O_MAXSMT:
zero = m_arith.mk_numeral(rational(0), false);
for (unsigned i = 0; i < o.m_terms.size(); ++i) {
args.push_back(m.mk_ite(o.m_terms[i], zero, m_arith.mk_numeral(o.m_weights[i], false)));
}
result = m_arith.mk_add(args.size(), args.c_ptr());
break;
case O_MAXIMIZE:
result = o.m_term;
if (m_arith.is_arith_expr(result)) {
result = m_arith.mk_uminus(result);
}
else if (m_bv.is_bv(result)) {
result = m_bv.mk_bv_neg(result);
}
else {
UNREACHABLE();
}
break;
case O_MINIMIZE:
result = o.m_term;
break;
}
return result;
}
unsigned context::add_soft_constraint(expr* f, rational const& w, symbol const& id) {
clear_state();
return m_scoped_state.add(f, w, id);
@ -1328,14 +1365,21 @@ namespace opt {
}
std::string context::to_string() const {
return to_string(m_scoped_state.m_hard, m_scoped_state.m_objectives);
}
std::string context::to_string_internal() const {
return to_string(m_hard_constraints, m_objectives);
}
std::string context::to_string(expr_ref_vector const& hard, vector<objective> const& objectives) const {
smt2_pp_environment_dbg env(m);
ast_pp_util visitor(m);
std::ostringstream out;
#define PP(_e_) ast_smt2_pp(out, _e_, env);
visitor.collect(m_scoped_state.m_hard);
visitor.collect(hard);
for (unsigned i = 0; i < m_scoped_state.m_objectives.size(); ++i) {
objective const& obj = m_scoped_state.m_objectives[i];
for (unsigned i = 0; i < objectives.size(); ++i) {
objective const& obj = objectives[i];
switch(obj.m_type) {
case O_MAXIMIZE:
case O_MINIMIZE:
@ -1351,33 +1395,34 @@ namespace opt {
}
visitor.display_decls(out);
visitor.display_asserts(out, m_scoped_state.m_hard, m_pp_neat);
for (unsigned i = 0; i < m_scoped_state.m_objectives.size(); ++i) {
objective const& obj = m_scoped_state.m_objectives[i];
visitor.display_asserts(out, hard, m_pp_neat);
for (unsigned i = 0; i < objectives.size(); ++i) {
objective const& obj = objectives[i];
switch(obj.m_type) {
case O_MAXIMIZE:
out << "(maximize ";
PP(obj.m_term);
ast_smt2_pp(out, obj.m_term, env);
out << ")\n";
break;
case O_MINIMIZE:
out << "(minimize ";
PP(obj.m_term);
ast_smt2_pp(out, obj.m_term, env);
out << ")\n";
break;
case O_MAXSMT:
for (unsigned j = 0; j < obj.m_terms.size(); ++j) {
out << "(assert-soft ";
PP(obj.m_terms[j]);
ast_smt2_pp(out, obj.m_terms[j], env);
rational w = obj.m_weights[j];
if (w.is_int()) {
out << " :weight " << w;
}
else {
out << " :dweight " << w;
}
w.display_decimal(out << " :weight ", 3, true);
if (obj.m_id != symbol::null) {
out << " :id " << obj.m_id;
if (is_smt2_quoted_symbol(obj.m_id)) {
out << " :id " << mk_smt2_quoted_symbol(obj.m_id);
}
else {
out << " :id " << obj.m_id;
}
}
out << ")\n";
}

7
src/opt/opt_context.h
View file

@ -175,6 +175,8 @@ namespace opt {
unsigned add_objective(app* t, bool is_max);
void add_hard_constraint(expr* f);
void get_hard_constraints(expr_ref_vector& hard);
expr_ref get_objective(unsigned i);
virtual void push();
virtual void pop(unsigned n);
@ -208,7 +210,7 @@ namespace opt {
std::string to_string() const;
virtual unsigned num_objectives() { return m_objectives.size(); }
virtual unsigned num_objectives() { return m_scoped_state.m_objectives.size(); }
virtual expr_ref mk_gt(unsigned i, model_ref& model);
virtual expr_ref mk_ge(unsigned i, model_ref& model);
virtual expr_ref mk_le(unsigned i, model_ref& model);
@ -284,6 +286,9 @@ namespace opt {
void display_objective(std::ostream& out, objective const& obj) const;
void display_bounds(std::ostream& out, bounds_t const& b) const;
std::string to_string(expr_ref_vector const& hard, vector<objective> const& objectives) const;
std::string to_string_internal() const;
void validate_lex();

2
src/smt/smt_internalizer.cpp
View file

@ -1281,7 +1281,7 @@ namespace smt {
The deletion event handler is ignored if binary clause optimization is applicable.
*/
clause * context::mk_clause(unsigned num_lits, literal * lits, justification * j, clause_kind k, clause_del_eh * del_eh) {
TRACE("mk_clause", tout << "creating clause:\n"; display_literals(tout, num_lits, lits); tout << "\n";);
TRACE("mk_clause", tout << "creating clause:\n"; display_literals_verbose(tout, num_lits, lits); tout << "\n";);
switch (k) {
case CLS_AUX: {
literal_buffer simp_lits;

2
src/smt/theory_arith_aux.h
View file

@ -1709,7 +1709,7 @@ namespace smt {
SASSERT(!maintain_integrality || valid_assignment());
SASSERT(satisfy_bounds());
}
TRACE("opt", display(tout););
TRACE("opt_verbose", display(tout););
return (best_efforts>0 || ctx.get_cancel_flag())?BEST_EFFORT:result;
}

2
src/smt/theory_arith_int.h
View file

@ -1385,7 +1385,7 @@ namespace smt {
m_branch_cut_counter++;
// TODO: add giveup code
if (m_branch_cut_counter % m_params.m_arith_branch_cut_ratio == 0) {
TRACE("opt", display(tout););
TRACE("opt_verbose", display(tout););
move_non_base_vars_to_bounds();
if (!make_feasible()) {
TRACE("arith_int", tout << "failed to move variables to bounds.\n";);

25
src/smt/theory_pb.cpp
View file

@ -321,7 +321,8 @@ namespace smt {
if (m_simplex.upper_valid(v)) {
m_simplex.get_upper(v, last_bound);
if (m_mpq_inf_mgr.gt(bound, last_bound)) {
literal lit = m_explain_upper.get(v, null_literal);
literal lit = m_explain_upper.get(v, null_literal);
TRACE("pb", tout << ~lit << " " << ~explain << "\n";);
get_context().mk_clause(~lit, ~explain, justify(~lit, ~explain));
return false;
}
@ -342,6 +343,7 @@ namespace smt {
m_simplex.get_lower(v, last_bound);
if (m_mpq_inf_mgr.gt(last_bound, bound)) {
literal lit = m_explain_lower.get(v, null_literal);
TRACE("pb", tout << ~lit << " " << ~explain << "\n";);
get_context().mk_clause(~lit, ~explain, justify(~lit, ~explain));
return false;
}
@ -405,6 +407,7 @@ namespace smt {
if (proofs_enabled()) {
js = alloc(theory_lemma_justification, get_id(), ctx, lits.size(), lits.c_ptr());
}
TRACE("pb", tout << lits << "\n";);
ctx.mk_clause(lits.size(), lits.c_ptr(), js, CLS_AUX_LEMMA, 0);
return false;
@ -515,11 +518,10 @@ namespace smt {
++log;
n *= 2;
}
unsigned th = args.size()*log; // 10*
unsigned th = args.size()*log;
c->m_compilation_threshold = th;
IF_VERBOSE(2, verbose_stream() << "(smt.pb setting compilation threhshold to " << th << ")\n";);
IF_VERBOSE(2, verbose_stream() << "(smt.pb setting compilation threshold to " << th << " " << c->k() << ")\n";);
TRACE("pb", tout << "compilation threshold: " << th << "\n";);
//compile_ineq(*c);
}
else {
c->m_compilation_threshold = UINT_MAX;
@ -1247,9 +1249,9 @@ namespace smt {
literal_vector in;
for (unsigned i = 0; i < num_args; ++i) {
rational n = c.coeff(i);
lbool val = ctx.get_assignment(c.lit());
if (val != l_undef &&
ctx.get_assign_level(thl) == ctx.get_base_level()) {
literal lit = c.lit(i);
lbool val = ctx.get_assignment(lit);
if (val != l_undef && ctx.get_assign_level(lit) == ctx.get_base_level()) {
if (val == l_true) {
unsigned m = n.get_unsigned();
if (k < m) {
@ -1264,6 +1266,8 @@ namespace smt {
n -= rational::one();
}
}
TRACE("pb", tout << in << " >= " << k << "\n";);
if (ctx.get_assignment(thl) == l_true &&
@ -1272,6 +1276,7 @@ namespace smt {
psort_nw<psort_expr> sortnw(ps);
sortnw.m_stats.reset();
at_least_k = sortnw.ge(false, k, in.size(), in.c_ptr());
TRACE("pb", tout << ~thl << " " << at_least_k << "\n";);
ctx.mk_clause(~thl, at_least_k, justify(~thl, at_least_k));
m_stats.m_num_compiled_vars += sortnw.m_stats.m_num_compiled_vars;
m_stats.m_num_compiled_clauses += sortnw.m_stats.m_num_compiled_clauses;
@ -1281,6 +1286,7 @@ namespace smt {
psort_nw<psort_expr> sortnw(ps);
sortnw.m_stats.reset();
literal at_least_k = sortnw.ge(true, k, in.size(), in.c_ptr());
TRACE("pb", tout << ~thl << " " << at_least_k << "\n";);
ctx.mk_clause(~thl, at_least_k, justify(~thl, at_least_k));
ctx.mk_clause(~at_least_k, thl, justify(thl, ~at_least_k));
m_stats.m_num_compiled_vars += sortnw.m_stats.m_num_compiled_vars;
@ -1290,7 +1296,6 @@ namespace smt {
<< "(smt.pb compile sorting network bound: "
<< k << " literals: " << in.size() << ")\n";);
TRACE("pb", tout << thl << "\n";);
// auxiliary clauses get removed when popping scopes.
// we have to recompile the circuit after back-tracking.
c.m_compiled = l_false;
@ -1300,7 +1305,6 @@ namespace smt {
void theory_pb::init_search_eh() {
m_to_compile.reset();
}
void theory_pb::push_scope_eh() {
@ -1329,6 +1333,7 @@ namespace smt {
m_ineq_rep.erase(r_info.m_rep);
}
}
m_to_compile.erase(c);
dealloc(c);
}
m_ineqs_lim.resize(new_lim);
@ -1454,6 +1459,7 @@ namespace smt {
if (proofs_enabled()) {
js = alloc(theory_lemma_justification, get_id(), ctx, lits.size(), lits.c_ptr());
}
TRACE("pb", tout << lits << "\n";);
ctx.mk_clause(lits.size(), lits.c_ptr(), js, CLS_AUX_LEMMA, 0);
}
@ -1760,6 +1766,7 @@ namespace smt {
for (unsigned i = 0; i < m_ineq_literals.size(); ++i) {
m_ineq_literals[i].neg();
}
TRACE("pb", tout << m_ineq_literals << "\n";);
ctx.mk_clause(m_ineq_literals.size(), m_ineq_literals.c_ptr(), justify(m_ineq_literals), CLS_AUX_LEMMA, 0);
break;
default: {

95
src/test/sorting_network.cpp
View file

@ -332,31 +332,106 @@ void test_sorting5(unsigned n, unsigned k) {
test_sorting_ge(n, k);
}
void test_at_most_1(unsigned n) {
expr_ref naive_at_most1(expr_ref_vector const& xs) {
ast_manager& m = xs.get_manager();
expr_ref_vector clauses(m);
for (unsigned i = 0; i < xs.size(); ++i) {
for (unsigned j = i + 1; j < xs.size(); ++j) {
clauses.push_back(m.mk_not(m.mk_and(xs[i], xs[j])));
}
}
return mk_and(clauses);
}
void test_at_most_1(unsigned n, bool full) {
ast_manager m;
reg_decl_plugins(m);
expr_ref_vector in(m), out(m);
for (unsigned i = 0; i < n; ++i) {
in.push_back(m.mk_fresh_const("a",m.mk_bool_sort()));
}
ast_ext2 ext(m);
psort_nw<ast_ext2> sn(ext);
expr_ref result1(m), result2(m);
result1 = sn.le(full, 1, in.size(), in.c_ptr());
result2 = naive_at_most1(in);
std::cout << "clauses: " << ext.m_clauses << "\n-----\n";
smt_params fp;
smt::kernel solver(m, fp);
for (unsigned i = 0; i < ext.m_clauses.size(); ++i) {
solver.assert_expr(ext.m_clauses[i].get());
}
lbool res;
if (full) {
solver.push();
solver.assert_expr(m.mk_not(m.mk_eq(result1, result2)));
std::cout << result1 << "\n";
res = solver.check();
SASSERT(res == l_false);
solver.pop(1);
}
if (n >= 9) return;
for (unsigned i = 0; i < static_cast<unsigned>(1 << n); ++i) {
std::cout << "checking: " << n << ": " << i << "\n";
solver.push();
unsigned k = 0;
for (unsigned j = 0; j < n; ++j) {
bool is_true = (i & (1 << j)) != 0;
expr_ref atom(m);
atom = is_true ? in[j].get() : m.mk_not(in[j].get());
solver.assert_expr(atom);
std::cout << atom << "\n";
if (is_true) ++k;
}
res = solver.check();
SASSERT(res == l_true);
if (k > 1) {
solver.assert_expr(result1);
}
else if (!full) {
solver.pop(1);
continue;
}
else {
solver.assert_expr(m.mk_not(result1));
}
res = solver.check();
SASSERT(res == l_false);
solver.pop(1);
}
}
static void test_at_most1() {
ast_manager m;
reg_decl_plugins(m);
expr_ref_vector in(m), out(m);
for (unsigned i = 0; i < 5; ++i) {
in.push_back(m.mk_fresh_const("a",m.mk_bool_sort()));
}
in[4] = in[3];
ast_ext2 ext(m);
psort_nw<ast_ext2> sn(ext);
expr_ref result(m);
result = sn.le(false, 1, in.size(), in.c_ptr());
result = sn.le(true, 1, in.size(), in.c_ptr());
std::cout << result << "\n";
std::cout << ext.m_clauses << "\n";
}
void tst_sorting_network() {
test_at_most_1(1);
test_at_most_1(2);
test_at_most_1(3);
test_at_most_1(4);
test_at_most_1(5);
test_at_most_1(10);
return;
for (unsigned i = 1; i < 17; ++i) {
test_at_most_1(i, true);
test_at_most_1(i, false);
}
test_at_most1();
test_sorting_eq(11,7);
for (unsigned n = 3; n < 20; n += 2) {

4
src/util/mpq.cpp
View file

@ -153,7 +153,7 @@ void mpq_manager<SYNCH>::display_smt2(std::ostream & out, mpq const & a, bool de
}
template<bool SYNCH>
void mpq_manager<SYNCH>::display_decimal(std::ostream & out, mpq const & a, unsigned prec) {
void mpq_manager<SYNCH>::display_decimal(std::ostream & out, mpq const & a, unsigned prec, bool truncate) {
mpz n1, d1, v1;
get_numerator(a, n1);
get_denominator(a, d1);
@ -177,7 +177,7 @@ void mpq_manager<SYNCH>::display_decimal(std::ostream & out, mpq const & a, unsi
if (is_zero(n1))
goto end; // number is precise
}
out << "?";
if (!truncate) out << "?";
end:
del(ten); del(n1); del(d1); del(v1);
}

2
src/util/mpq.h
View file

@ -265,7 +265,7 @@ public:
void display_smt2(std::ostream & out, mpq const & a, bool decimal) const;
void display_decimal(std::ostream & out, mpq const & a, unsigned prec);
void display_decimal(std::ostream & out, mpq const & a, unsigned prec, bool truncate = false);
void add(mpz const & a, mpz const & b, mpz & c) { mpz_manager<SYNCH>::add(a, b, c); }

2
src/util/rational.h
View file

@ -86,7 +86,7 @@ public:
void display(std::ostream & out) const { return m().display(out, m_val); }
void display_decimal(std::ostream & out, unsigned prec) const { return m().display_decimal(out, m_val, prec); }
void display_decimal(std::ostream & out, unsigned prec, bool truncate = false) const { return m().display_decimal(out, m_val, prec, truncate); }
bool is_uint64() const { return m().is_uint64(m_val); }

88
src/util/sorting_network.h
View file

@ -234,19 +234,28 @@ Notes:
private:
literal mk_at_most_1(bool full, unsigned n, literal const* xs) {
TRACE("pb", tout << (full?"full":"partial") << " ";
for (unsigned i = 0; i < n; ++i) tout << xs[i] << " ";
tout << "\n";);
if (!full && n >= 4) {
return mk_at_most_1_bimander(n, xs);
}
literal_vector in(n, xs);
literal result = ctx.fresh();
literal result = fresh();
unsigned inc_size = 4;
literal_vector ands;
ands.push_back(result);
while (!in.empty()) {
literal_vector ors;
unsigned i = 0;
unsigned n = in.size();
bool last = n <= inc_size;
for (; i + inc_size < n; i += inc_size) {
mk_at_most_1_small(full, last, inc_size, in.c_ptr() + i, result, ors);
mk_at_most_1_small(full, last, inc_size, in.c_ptr() + i, result, ands, ors);
}
if (i < n) {
mk_at_most_1_small(full, last, n - i, in.c_ptr() + i, result, ors);
mk_at_most_1_small(full, last, n - i, in.c_ptr() + i, result, ands, ors);
}
if (last) {
break;
@ -255,12 +264,22 @@ Notes:
in.append(ors);
ors.reset();
}
if (full) {
add_clause(ands);
}
return result;
}
void mk_at_most_1_small(bool full, bool last, unsigned n, literal const* xs, literal result, literal_vector& ors) {
void mk_at_most_1_small(bool full, bool last, unsigned n, literal const* xs, literal result, literal_vector& ands, literal_vector& ors) {
SASSERT(n > 0);
if (n == 1) {
if (!last) {
ors.push_back(xs[0]);
}
return;
}
if (!last) {
literal ex = ctx.fresh();
literal ex = fresh();
for (unsigned j = 0; j < n; ++j) {
add_clause(ctx.mk_not(xs[j]), ex);
}
@ -271,16 +290,59 @@ Notes:
}
ors.push_back(ex);
}
// result => xs[0] + ... + xs[n-1] <= 1
for (unsigned i = 0; i < n; ++i) {
for (unsigned j = i + 1; j < n; ++j) {
add_clause(ctx.mk_not(result), ctx.mk_not(xs[i]), ctx.mk_not(xs[j]));
}
if (full) {
add_clause(result, xs[i]);
}
// xs[0] + ... + xs[n-1] <= 1 => and_x
if (full) {
literal and_i = fresh();
for (unsigned i = 0; i < n; ++i) {
literal_vector lits;
lits.push_back(and_i);
for (unsigned j = 0; j < n; ++j) {
if (j != i) lits.push_back(xs[j]);
}
add_clause(lits);
}
ands.push_back(ctx.mk_not(and_i));
}
}
literal mk_at_most_1_bimander(unsigned n, literal const* xs) {
literal_vector in(n, xs);
literal result = fresh();
unsigned inc_size = 2;
bool last = false;
bool full = false;
literal_vector ors, ands;
unsigned i = 0;
for (; i + inc_size < n; i += inc_size) {
mk_at_most_1_small(full, last, inc_size, in.c_ptr() + i, result, ands, ors);
}
if (i < n) {
mk_at_most_1_small(full, last, n - i, in.c_ptr() + i, result, ands, ors);
}
unsigned nbits = 0;
while (static_cast<unsigned>(1 << nbits) < ors.size()) {
++nbits;
}
literal_vector bits;
for (unsigned k = 0; k < nbits; ++k) {
bits.push_back(fresh());
}
for (i = 0; i < ors.size(); ++i) {
for (unsigned k = 0; k < nbits; ++k) {
bool bit_set = (i & (static_cast<unsigned>(1 << k))) != 0;
add_clause(ctx.mk_not(result), ctx.mk_not(ors[i]), bit_set ? bits[k] : ctx.mk_not(bits[k]));
}
}
return result;
}
std::ostream& pp(std::ostream& out, unsigned n, literal const* lits) {
for (unsigned i = 0; i < n; ++i) ctx.pp(out, lits[i]) << " ";
return out;
@ -344,9 +406,13 @@ Notes:
literal lits[2] = { l1, l2 };
add_clause(2, lits);
}
void add_clause(literal_vector const& lits) {
add_clause(lits.size(), lits.c_ptr());
}
void add_clause(unsigned n, literal const* ls) {
m_stats.m_num_compiled_clauses++;
literal_vector tmp(n, ls);
TRACE("pb", for (unsigned i = 0; i < n; ++i) tout << ls[i] << " "; tout << "\n";);
ctx.mk_clause(n, tmp.c_ptr());
}
@ -383,7 +449,7 @@ Notes:
}
void card(unsigned k, unsigned n, literal const* xs, literal_vector& out) {
TRACE("pb", tout << "card k:" << k << " n: " << n << "\n";);
TRACE("pb", tout << "card k: " << k << " n: " << n << "\n";);
if (n <= k) {
psort_nw<psort_expr>::sorting(n, xs, out);
}
@ -397,7 +463,7 @@ Notes:
card(k, n-l, xs + l, out2);
smerge(k, out1.size(), out1.c_ptr(), out2.size(), out2.c_ptr(), out);
}
TRACE("pb", tout << "card k:" << k << " n: " << n << "\n";
TRACE("pb", tout << "card k: " << k << " n: " << n << "\n";
pp(tout << "in:", n, xs) << "\n";
pp(tout << "out:", out) << "\n";);
@ -743,7 +809,7 @@ Notes:
if (j < b) {
ls.push_back(as[i]);
ls.push_back(bs[j]);
add_clause(ls.size(), ls.c_ptr());
add_clause(ls);
ls.pop_back();
ls.pop_back();
}
@ -804,7 +870,7 @@ Notes:
pp(tout, lits) << "\n";);
SASSERT(k + offset <= n);
if (k == 0) {
add_clause(lits.size(), lits.c_ptr());
add_clause(lits);
return;
}
for (unsigned i = offset; i < n - k + 1; ++i) {