z3-z3-4.13.0.src.muz.rel.doc.cpp Maven / Gradle / Ivy
The newest version!
/*++
Copyright (c) 2014 Microsoft Corporation
Module Name:
doc.cpp
Abstract:
difference of cubes.
Author:
Nuno Lopes (a-nlopes) 2013-03-01
Nikolaj Bjorner (nbjorner) 2014-09-15
Revision History:
Based on ternary_diff_bitvector by Nuno Lopes.
--*/
#include "muz/rel/doc.h"
#include "smt/smt_kernel.h"
#include "ast/rewriter/expr_safe_replace.h"
#include "smt/params/smt_params.h"
#include "ast/ast_util.h"
#include "ast/ast_pp.h"
doc_manager::doc_manager(unsigned n): m(n), m_alloc("doc") {
m_full = m.allocateX();
}
doc_manager::~doc_manager() {
m.deallocate(m_full);
}
doc* doc_manager::allocate() {
return allocate(m.allocate());
}
doc* doc_manager::allocate1() {
return allocate(m.allocate1());
}
doc* doc_manager::allocate0() {
return allocate(m.allocate0());
}
doc* doc_manager::allocateX() {
return allocate(m.allocateX());
}
doc* doc_manager::allocate(doc const& src) {
doc* r = allocate(m.allocate(src.pos()));
for (unsigned i = 0; i < src.neg().size(); ++i) {
r->neg().push_back(m.allocate(src.neg()[i]));
}
return r;
}
doc* doc_manager::allocate(tbv* t) {
SASSERT(t);
void* mm = m_alloc.allocate(sizeof(doc));
return new (mm) doc(t);
}
doc* doc_manager::allocate(tbv const& src) {
return allocate(m.allocate(src));
}
doc* doc_manager::allocate(uint64_t n) {
return allocate(m.allocate(n));
}
doc* doc_manager::allocate(rational const& r) {
return allocate(m.allocate(r));
}
doc* doc_manager::allocate(uint64_t n, unsigned hi, unsigned lo) {
return allocate(m.allocate(n, hi, lo));
}
doc* doc_manager::allocate(doc const& src, unsigned const* permutation) {
doc* r = allocate(m.allocate(src.pos(), permutation));
for (unsigned i = 0; i < src.neg().size(); ++i) {
r->neg().push_back(m.allocate(src.neg()[i], permutation));
}
return r;
}
void doc_manager::deallocate(doc* src) {
if (!src) return;
m.deallocate(&src->pos());
src->neg().reset(m);
src->~doc();
m_alloc.deallocate(sizeof(doc), src);
}
void doc_manager::copy(doc& dst, doc const& src) {
m.copy(dst.pos(), src.pos());
dst.neg().reset(m);
for (unsigned i = 0; i < src.neg().size(); ++i) {
dst.neg().push_back(m.allocate(src.neg()[i]));
}
}
doc& doc_manager::fill0(doc& src) {
src.neg().reset(m);
m.fill0(src.pos());
return src;
}
doc& doc_manager::fill1(doc& src) {
src.neg().reset(m);
m.fill1(src.pos());
return src;
}
doc& doc_manager::fillX(doc& src) {
src.neg().reset(m);
m.fillX(src.pos());
return src;
}
unsigned doc_manager::get_size_estimate_bytes(const doc& d) const {
return m.get_size_estimate_bytes(d.pos())
+ d.neg().get_size_estimate_bytes(m)
+ sizeof(doc);
}
bool doc_manager::set_and(doc& dst, doc const& src) {
// (A \ B) & (C \ D) = (A & C) \ (B u D)
if (!m.set_and(dst.pos(), src.pos())) return false;
dst.neg().intersect(m, dst.pos());
tbv_ref t(m);
for (unsigned i = 0; i < src.neg().size(); ++i) {
t = m.allocate(src.neg()[i]);
if (m.set_and(*t, dst.pos())) {
dst.neg().insert(m, t.detach());
}
}
return fold_neg(dst);
}
bool doc_manager::set_and(doc& dst, tbv const& src) {
// (A \ B) & C = (A & C) \ (B & C)
if (!m.set_and(dst.pos(), src)) return false;
dst.neg().intersect(m, src);
return fold_neg(dst);
}
bool doc_manager::well_formed(doc const& d) const {
if (!m.is_well_formed(d.pos())) return false;
for (unsigned i = 0; i < d.neg().size(); ++i) {
if (!m.is_well_formed(d.neg()[i])) return false;
if (!m.contains(d.pos(), d.neg()[i])) return false;
}
return true;
}
bool doc_manager::fold_neg(doc& dst) {
start_over:
for (unsigned i = 0; i < dst.neg().size(); ++i) {
if (m.contains(dst.neg()[i], dst.pos()))
return false;
unsigned index;
unsigned count = diff_by_012(dst.pos(), dst.neg()[i], index);
if (count != 2) {
if (count == 0) {
return false;
}
else if (count == 3) {
dst.neg().erase(tbvm(), i);
--i;
}
else { // count == 1:
m.set(dst.pos(), index, neg(dst.neg()[i][index]));
dst.neg().intersect(tbvm(), dst.pos());
goto start_over;
}
}
}
SASSERT(well_formed(dst));
return true;
}
unsigned doc_manager::diff_by_012(tbv const& pos, tbv const& neg, unsigned& index) {
unsigned n = num_tbits();
unsigned count = 0;
for (unsigned i = 0; i < n; ++i) {
tbit b1 = pos[i];
tbit b2 = neg[i];
SASSERT(b1 != BIT_z && b2 != BIT_z);
if (b1 != b2) {
if (count == 1) return 2;
if (b1 == BIT_x) {
index = i;
count = 1;
}
else if (b2 != BIT_x) {
return 3;
}
}
}
return count;
}
void doc_manager::set(doc& d, unsigned idx, tbit value) {
m.set(d.pos(), idx, value);
for (unsigned i = 0; i < d.neg().size(); ++i) {
tbit b = d.neg()[i][idx];
if (b != BIT_x && value != BIT_x && value != b) {
d.neg().erase(tbvm(), i);
--i;
}
else {
m.set(d.neg()[i], idx, value);
}
}
}
//
// merge range from [lo:lo+length-1] with each index in equivalence class.
// under assumption of equalities and columns that are discarded.
//
bool doc_manager::merge(
doc& d, unsigned lo, unsigned length,
subset_ints const& equalities, bit_vector const& discard_cols) {
for (unsigned i = 0; i < length; ++i) {
unsigned idx = lo + i;
if (!merge(d, idx, equalities, discard_cols)) return false;
}
return true;
}
bool doc_manager::merge(doc& d, unsigned idx, subset_ints const& equalities,
bit_vector const& discard_cols) {
unsigned root = equalities.find(idx);
idx = root;
unsigned num_x = 0;
unsigned root1 = root;
tbit value = BIT_x;
do {
switch (d[idx]) {
case BIT_0:
if (value == BIT_1) return false;
value = BIT_0;
break;
case BIT_1:
if (value == BIT_0) return false;
value = BIT_1;
break;
case BIT_x:
++num_x;
if (!discard_cols.get(idx)) {
root1 = idx;
}
break;
default:
UNREACHABLE();
break;
}
idx = equalities.next(idx);
}
while (idx != root);
TRACE("doc", tout << "num_x: " << num_x << " value: " << value << "\n";);
if (num_x == 0) {
// nothing to do.
}
else if (value != BIT_x) {
do {
if (d[idx] == BIT_x) {
set(d, idx, value);
}
idx = equalities.next(idx);
}
while (idx != root);
}
else {
bool all_x = true;
if (!d.neg().is_empty()) {
idx = root;
do {
for (unsigned i = 0; all_x && i < d.neg().size(); ++i) {
all_x = (BIT_x == d.neg()[i][idx]);
}
idx = equalities.next(idx);
}
while (idx != root && all_x);
}
idx = root;
do {
if ((!discard_cols.get(idx) || !all_x) && idx != root1) {
tbv* t = m.allocate(d.pos());
m.set(*t, idx, BIT_0);
m.set(*t, root1, BIT_1);
d.neg().insert(tbvm(), t);
t = m.allocate(d.pos());
m.set(*t, idx, BIT_1);
m.set(*t, root1, BIT_0);
d.neg().insert(tbvm(), t);
}
idx = equalities.next(idx);
}
while (idx != root);
}
return true;
}
bool doc_manager::intersect(doc const& A, doc const& B, doc& result) {
copy(result, A);
return set_and(result, B);
}
//
// 1. If n = 0,1: can project directly.
// 2. If tbv_i uses X in all positions with vars or constant where tbv is constant: can project directly.
// 3. Perform resolution on remaining tbv_i
//
// tbv & ~tbv1 & ~tbv2 & .. & ~tbv_n
// Semantics of ~tbv1 is that it is a clause of literals.
// indices where BIT_1 is set are negative.
// indices where BIT_0 is set are positive.
//
doc* doc_manager::project(doc_manager& dstm, bit_vector const& to_delete, doc const& src) {
tbv_manager& dstt = dstm.m;
tbv_ref t(dstt);
t = dstt.project(to_delete, src.pos());
doc* r = dstm.allocate(t.detach());
SASSERT(r);
if (src.neg().is_empty()) {
return r;
}
//
// A negation can be projected directly if it does not constrain
// deleted variables.
//
tbv_vector todo, new_todo;
for (unsigned i = 0; i < src.neg().size(); ++i) {
todo.push_back(tbvm().allocate(src.neg()[i]));
}
unsigned idx;
bool done = false;
while (!todo.empty() && !done) {
switch(pick_resolvent(src.pos(), todo, to_delete, idx)) {
case project_is_empty:
t = dstt.allocate(r->pos());
r->neg().push_back(t.detach());
done = true;
break;
case project_monolithic:
done = true;
break;
case project_neg:
case project_pos:
for (unsigned i = 0; i < todo.size(); ++i) {
tbv& tx = *todo[i];
if (tx[idx] == BIT_x) {
new_todo.push_back(&tx);
}
else {
m.deallocate(&tx);
}
}
std::swap(new_todo, todo);
new_todo.reset();
break;
case project_resolve: {
utbv pos, neg;
for (unsigned i = 0; i < todo.size(); ++i) {
tbv& tx = *todo[i];
switch(tx[idx]) {
case BIT_x: new_todo.push_back(&tx); break;
case BIT_0: neg.push_back(&tx); break;
case BIT_1: pos.push_back(&tx); break;
default: UNREACHABLE(); break;
}
}
TRACE("doc",
tout << "pos: ";
for (unsigned i = 0; i < pos.size(); ++i) {
tbvm().display(tout, pos[i]) << " ";
}
tout << "\nneg: ";
for (unsigned i = 0; i < neg.size(); ++i) {
tbvm().display(tout, neg[i]) << " ";
}
tout << "\n";
);
SASSERT(pos.size() > 0 && neg.size() > 0);
tbv_ref t1(m);
for (unsigned j = 0; j < pos.size(); ++j) {
for (unsigned k = 0; k < neg.size(); ++k) {
t1 = m.allocate(pos[j]);
m.set(*t1, idx, BIT_x);
if (tbvm().set_and(*t1, neg[k])) {
m.set(*t1, idx, BIT_x);
new_todo.push_back(t1.detach());
}
}
}
pos.reset(m);
neg.reset(m);
std::swap(todo, new_todo);
new_todo.reset();
break;
}
case project_done: {
for (unsigned i = 0; i < todo.size(); ++i) {
t = dstt.project(to_delete, *todo[i]);
if (dstt.equals(r->pos(), *t)) {
r->neg().reset(dstt);
r->neg().push_back(t.detach());
break;
}
if (r->neg().size() > 0 && dstt.equals(r->neg()[0], *t)) {
continue;
}
r->neg().push_back(t.detach());
}
done = true;
break;
}
}
}
for (unsigned i = 0; i < todo.size(); ++i) {
m.deallocate(todo[i]);
}
return r;
}
doc* doc_manager::join(const doc& d1, const doc& d2, doc_manager& dm1,
const unsigned_vector& cols1,
const unsigned_vector& cols2) {
doc_ref d(*this, allocateX());
tbv_ref t(m);
tbv& pos = d->pos();
utbv& neg = d->neg();
unsigned mid = dm1.num_tbits();
unsigned hi = num_tbits();
m.set(pos, d1.pos(), mid - 1, 0);
m.set(pos, d2.pos(), hi - 1, mid);
SASSERT(well_formed(*d));
// first fix bits
for (unsigned i = 0; i < cols1.size(); ++i) {
unsigned idx1 = cols1[i];
unsigned idx2 = mid + cols2[i];
tbit v1 = pos[idx1];
tbit v2 = pos[idx2];
if (v1 == BIT_x) {
if (v2 != BIT_x)
m.set(pos, idx1, v2);
}
else if (v2 == BIT_x) {
m.set(pos, idx2, v1);
}
else if (v1 != v2) {
// columns don't match
return nullptr;
}
SASSERT(well_formed(*d));
}
// fix equality of don't care columns
for (unsigned i = 0; i < cols1.size(); ++i) {
unsigned idx1 = cols1[i];
unsigned idx2 = mid + cols2[i];
unsigned v1 = pos[idx1];
unsigned v2 = pos[idx2];
if (v1 == BIT_x && v2 == BIT_x) {
// add to subtracted TBVs: 1xx0 and 0xx1
t = m.allocate(pos);
m.set(*t, idx1, BIT_0);
m.set(*t, idx2, BIT_1);
neg.push_back(t.detach());
t = m.allocate(pos);
m.set(*t, idx1, BIT_1);
m.set(*t, idx2, BIT_0);
neg.push_back(t.detach());
}
SASSERT(well_formed(*d));
}
// handle subtracted TBVs: 1010 -> 1010xxx
for (unsigned i = 0; i < d1.neg().size(); ++i) {
t = m.allocateX();
m.set(*t, d1.neg()[i], mid - 1, 0);
if (m.set_and(*t, pos))
neg.push_back(t.detach());
SASSERT(well_formed(*d));
}
for (unsigned i = 0; i < d2.neg().size(); ++i) {
t = m.allocateX();
m.set(*t, d2.neg()[i], hi - 1, mid);
if (m.set_and(*t, pos))
neg.push_back(t.detach());
SASSERT(well_formed(*d));
}
SASSERT(well_formed(*d));
return d.detach();
}
doc_manager::project_action_t
doc_manager::pick_resolvent(
tbv const& pos, tbv_vector const& neg, bit_vector const& to_delete, unsigned& idx) {
if (neg.empty()) return project_done;
for (unsigned j = 0; j < neg.size(); ++j) {
if (m.equals(pos, *neg[j])) return project_is_empty;
}
unsigned best_pos = UINT_MAX;
unsigned best_neg = UINT_MAX;
unsigned best_idx = UINT_MAX;
for (unsigned i = 0; i < num_tbits(); ++i) {
if (!to_delete.get(i)) continue;
if (pos[i] != BIT_x) continue;
unsigned num_pos = 0, num_neg = 0;
tbit b1 = (*neg[0])[i];
if (b1 == BIT_0) num_neg++;
if (b1 == BIT_1) num_pos++;
bool monolithic = true;
for (unsigned j = 1; j < neg.size(); ++j) {
tbit b2 = (*neg[j])[i];
if (b1 != b2) {
monolithic = false;
}
if (b2 == BIT_0) num_neg++;
if (b2 == BIT_1) num_pos++;
}
if (monolithic && b1 != BIT_x) {
idx = i;
return project_monolithic;
}
if (monolithic && b1 == BIT_x) {
continue;
}
SASSERT(!monolithic);
if (num_pos == 0) {
SASSERT(num_neg > 0);
idx = i;
return project_neg;
}
if (num_neg == 0) {
SASSERT(num_pos > 0);
idx = i;
return project_pos;
}
if ((best_pos >= num_pos && best_neg >= num_neg) ||
num_neg == 1 || num_pos == 1) {
best_pos = num_pos;
best_neg = num_neg;
best_idx = i;
}
}
if (best_idx != UINT_MAX) {
idx = best_idx;
return project_resolve;
}
else {
return project_done;
}
}
void doc_manager::complement(doc const& src, doc_vector& result) {
result.reset();
if (is_full(src)) {
return;
}
doc* r = allocateX();
r->neg().push_back(m.allocate(src.pos()));
result.push_back(r);
for (unsigned i = 0; i < src.neg().size(); ++i) {
result.push_back(allocate(src.neg()[i]));
}
}
// (A \ {A1}) \ (B \ {B1})
// (A & !A1 & & !B) | (A & B1 & !A1)
// A \ {A1 u B} u (A & B1) \ {A1}
void doc_manager::subtract(doc const& A, doc const& B, doc_vector& result) {
doc_ref r(*this);
tbv_ref t(m);
r = allocate(A);
t = m.allocate(B.pos());
if (m.set_and(*t, A.pos())) {
r->neg().insert(m, t.detach());
}
if (fold_neg(*r))
result.push_back(r.detach());
for (unsigned i = 0; i < B.neg().size(); ++i) {
r = allocate(A);
if (set_and(*r, B.neg()[i])) {
result.push_back(r.detach());
}
}
}
bool doc_manager::equals(doc const& a, doc const& b) const {
if (!m.equals(a.pos(), b.pos())) return false;
if (a.neg().size() != b.neg().size()) return false;
for (unsigned i = 0; i < a.neg().size(); ++i) {
if (!m.equals(a.neg()[i], b.neg()[i])) return false;
}
return true;
}
bool doc_manager::is_full(doc const& src) const {
return src.neg().is_empty() && m.equals(src.pos(), *m_full);
}
bool doc_manager::is_empty_complete(ast_manager& m, doc const& src) {
if (src.neg().size() == 0) return false;
smt_params fp;
smt::kernel s(m, fp);
expr_ref fml = to_formula(m, src);
s.assert_expr(fml);
lbool res = s.check();
if (res == l_true) {
return false;
}
SASSERT(res == l_false);
return true;
}
unsigned doc_manager::hash(doc const& src) const {
unsigned r = 0;
for (unsigned i = 0; i < src.neg().size(); ++i) {
r = 2*r + m.hash(src.neg()[i]);
}
return r + m.hash(src.pos());
}
// approximation
// A \ (A1 u A2) contains B \ (B1 u B2)
// if
// A contains B
// B1 contains A1 or B2 contains A1
// B1 contains A2 or B2 contains A2
bool doc_manager::contains(doc const& a, doc const& b) const {
if (!m.contains(a.pos(), b.pos())) return false;
for (unsigned i = 0; i < a.neg().size(); ++i) {
bool found = false;
for (unsigned j = 0; !found && j < b.neg().size(); ++j) {
found = m.contains(b.neg()[j],a.neg()[i]);
}
if (!found) return false;
}
return true;
}
bool doc_manager::contains(doc const& a, unsigned_vector const& colsa,
doc const& b, unsigned_vector const& colsb) const {
if (!m.contains(a.pos(), colsa, b.pos(), colsb))
return false;
for (unsigned i = 0; i < a.neg().size(); ++i) {
bool found = false;
for (unsigned j = 0; !found && j < b.neg().size(); ++j) {
found = m.contains(b.neg()[j], colsb, a.neg()[i], colsa);
}
if (!found) return false;
}
return true;
}
std::ostream& doc_manager::display(std::ostream& out, doc const& b) const {
if (num_tbits() == 0) return out << "[]";
return display(out, b, num_tbits()-1, 0);
}
std::ostream& doc_manager::display(std::ostream& out, doc const& b, unsigned hi, unsigned lo) const {
m.display(out, b.pos(), hi, lo);
if (b.neg().is_empty()) return out;
out << " \\ ";
b.neg().display(m, out, hi, lo);
return out;
}
void doc_manager::verify_project(ast_manager& m, doc_manager& dstm, bit_vector const& to_delete, doc const& src, doc const& dst) {
expr_ref fml1 = to_formula(m, src);
expr_ref fml2 = dstm.to_formula(m, dst);
project_rename(fml2, to_delete);
project_expand(fml1, to_delete);
check_equiv(m, fml1, fml2);
}
void doc_manager::check_equiv(ast_manager& m, expr* fml1, expr* fml2) {
smt_params fp;
smt::kernel solver(m, fp);
expr_ref fml(m);
fml = m.mk_not(m.mk_eq(fml1, fml2));
solver.assert_expr(fml);
lbool res = solver.check();
if (res != l_false) {
TRACE("doc",
tout << mk_pp(fml1, m) << "\n";
tout << mk_pp(fml2, m) << "\n";
);
UNREACHABLE();
throw 0;
}
SASSERT(res == l_false);
}
expr_ref doc_manager::to_formula(ast_manager & m, tbv const& src) {
expr_ref result(m);
expr_ref_vector conj(m);
for (unsigned i = 0; i < num_tbits(); ++i) {
switch (src[i]) {
case BIT_0:
conj.push_back(m.mk_not(m.mk_const(symbol(i), m.mk_bool_sort())));
break;
case BIT_1:
conj.push_back(m.mk_const(symbol(i), m.mk_bool_sort()));
break;
default:
break;
}
}
result = mk_and(m, conj.size(), conj.data());
return result;
}
expr_ref doc_manager::mk_var(ast_manager & m, unsigned i) {
return expr_ref(m.mk_const(symbol(i), m.mk_bool_sort()), m);
}
expr_ref doc_manager::to_formula(ast_manager& m, doc const& src) {
expr_ref result(m);
expr_ref_vector conj(m);
conj.push_back(to_formula(m, src.pos()));
for (unsigned i = 0; i < src.neg().size(); ++i) {
conj.push_back(m.mk_not(to_formula(m, src.neg()[i])));
}
result = mk_and(m, conj.size(), conj.data());
return result;
}
void doc_manager::project_expand(expr_ref& fml, bit_vector const& to_delete) {
ast_manager& m = fml.get_manager();
expr_ref tmp1(m), tmp2(m);
for (unsigned i = 0; i < num_tbits(); ++i) {
if (to_delete.get(i)) {
expr_safe_replace rep1(m), rep2(m);
rep1.insert(mk_var(m, i), m.mk_true());
rep1(fml, tmp1);
rep2.insert(mk_var(m, i), m.mk_false());
rep2(fml, tmp2);
if (tmp1 == tmp2) {
fml = tmp1;
}
else {
fml = m.mk_or(tmp1, tmp2);
}
}
}
}
void doc_manager::project_rename(expr_ref& fml, bit_vector const& to_delete) {
ast_manager& m = fml.get_manager();
expr_safe_replace rep(m);
for (unsigned i = 0, j = 0; i < num_tbits(); ++i) {
if (!to_delete.get(i)) {
rep.insert(mk_var(m, j), mk_var(m, i));
++j;
}
}
rep(fml);
}