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debug dio with static matrix
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@levnach
levnach committed Feb 11, 2025
1 parent 28fbc81 commit 536c51f
Showing 1 changed file with 71 additions and 86 deletions.
157 changes: 71 additions & 86 deletions src/math/lp/dioph_eq.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -60,7 +60,6 @@ namespace lp {
std::ostream& print_S(std::ostream & out) {
out << "S:\n";
for (unsigned i : m_s) {
out << "x" << m_eprime[i].m_e.j() << " ->\n";
print_eprime_entry(i, out);
}
return out;
Expand Down Expand Up @@ -120,7 +119,6 @@ namespace lp {
};
struct eprime_entry {
unsigned m_row_index; // the index of the row in the constraint matrix that m_e corresponds to
term_o m_e; // it will be used for debugging only
// we keep the dependency of the equation in m_l
// a more expensive alternative is to keep the history term of m_e : originally m_l is i, the index of row m_e was constructed from
u_dependency *m_l;
Expand Down Expand Up @@ -156,29 +154,40 @@ namespace lp {
return t;
}
private:
term_o create_eprime_entry_from_row(const row_strip<mpq>& row, unsigned row_index) {
// the row comes from lar_solver
void create_eprime_entry_from_row(const row_strip<mpq>& row, unsigned row_index) {
m_f.push_back(row_index);
eprime_entry& e = m_eprime[row_index];
const auto lcm = get_denominators_lcm(row);
#if Z3DEBUG
term_o t;
for (const auto & p: row)
if (lia.is_fixed(p.var()))
t.c() += p.coeff()*lia.lower_bound(p.var()).x;
else
t.add_monomial(lcm * p.coeff(), p.var());
t.c() *= lcm;
#endif
// init m_e_matrix and m_c
mpq & c = m_eprime[row_index].m_c;
for (const auto & p: row)
if (lia.is_fixed(p.var()))
u_dependency*& dep = e.m_l;
SASSERT(dep == nullptr);
mpq & c = e.m_c;
SASSERT(c.is_zero());

for (const auto & p: row) {
if (lia.is_fixed(p.var())) {
c += p.coeff()*lia.lower_bound(p.var()).x;
else
dep = lra.get_bound_constraint_witnesses_for_column(p.var());
}
else {
m_e_matrix.add_new_element(row_index, p.var(), lcm * p.coeff());
c *= lcm;
SASSERT(t == get_term_from_e_matrix(row_index));
return t;
}
}
c *= lcm;
e.m_entry_status = entry_status::F;
}

bool all_vars_are_int_and_small(const row_strip<mpq>& row) const {
for (const auto& p : row) {
if (!lia.column_is_int(p.var()))
return false;
if (p.coeff().is_big())
return false;
}
return true;
}


void init() {
m_e_matrix = static_matrix<mpq, impq>(lra.row_count(), lra.column_count());
m_report_branch = false;
Expand All @@ -188,36 +197,17 @@ namespace lp {
m_conflict_index = -1;
m_infeas_explanation.clear();
lia.get_term().clear();

auto all_vars_are_int_and_small = [this](const auto& row) {
for (const auto& p : row) {
if (!lia.column_is_int(p.var())) {
return false;
}
if (p.coeff().is_big())
return false;
}
return true;
};
m_eprime.clear();
m_eprime.resize(n_of_rows);
for (unsigned i = 0; i < n_of_rows; i++) {
auto & row = lra.get_row(i);
TRACE("dioph_eq", tout << "row "<< i <<":"; lia.display_row_info(tout, i) << "\n";);
if (!all_vars_are_int_and_small(row)) {
TRACE("dioph_eq", tout << "not all vars are int and small\n";);
m_eprime[i].m_entry_status = entry_status::NO_S_NO_F;
continue;
}
term_o t = create_eprime_entry_from_row(row, i);
m_eprime[i].m_entry_status = entry_status::F;
TRACE("dioph_eq", tout << "row = "; lra.print_row(row, tout) << std::endl;);
if (t.size() == 0) {
SASSERT(t.c().is_zero());
continue;
}
// eprime_pair pair = {t, lar_term(i)};
eprime_entry pair = {i, t, get_dep_from_row(row)};

m_f.push_back(static_cast<unsigned>(i));
m_eprime.push_back(pair);
create_eprime_entry_from_row(row, i);
TRACE("dioph_eq", print_eprime_entry(static_cast<unsigned>(i), tout););
}

Expand Down Expand Up @@ -254,9 +244,9 @@ namespace lp {
return std::string(is_fresh_var(j)? "~":"") + std::to_string(j);
}

bool has_fresh_var(const term_o & t) const {
for (const auto & p: t) {
if (is_fresh_var(p.j()))
bool has_fresh_var(unsigned row_index) const {
for (const auto & p: m_e_matrix.m_rows[row_index]) {
if (is_fresh_var(p.var()))
return true;
}
return false;
Expand Down Expand Up @@ -286,7 +276,7 @@ namespace lp {
TRACE("dioph_eq", print_eprime_entry(ep, tout) << std::endl;);
mpq g = gcd_of_row(row_index);
if (g.is_zero() || g.is_one()) {
SASSERT(g.is_one() || ep.m_e.c().is_zero());
SASSERT(g.is_one() || ep.m_c.is_zero());
return true;
}
TRACE("dioph_eq", tout << "g:" << g << std::endl;);
Expand All @@ -302,7 +292,7 @@ namespace lp {
}
// c_g is not integral
if (lra.settings().stats().m_dio_conflicts % lra.settings().dio_cut_from_proof_period() == 0 &&
!has_fresh_var(ep.m_e))
!has_fresh_var(ep.m_row_index))
prepare_lia_branch_report(ep, g, c_g);
return false;

Expand Down Expand Up @@ -569,29 +559,29 @@ namespace lp {
}
}

void substitute_var_on_f(unsigned k, int k_sign, const term_o& k_subst, u_dependency * dep, unsigned index_to_avoid) {
TRACE("dioph_eq", print_term_o(k_subst, tout<< "x" << k<< " -> ") << std::endl; tout << "dep:"; print_dep(tout, dep) << std::endl;);
for (unsigned e_index: m_f) {
if (e_index == index_to_avoid) continue;
term_o& e = m_eprime[e_index].m_e;
if (!e.contains(k)) continue;
// void substitute_var_on_f(unsigned k, int k_sign, const term_o& k_subst, u_dependency * dep, unsigned index_to_avoid) {
// TRACE("dioph_eq", print_term_o(k_subst, tout<< "x" << k<< " -> ") << std::endl; tout << "dep:"; print_dep(tout, dep) << std::endl;);
// for (unsigned e_index: m_f) {
// if (e_index == index_to_avoid) continue;
// term_o& e = m_eprime[e_index].m_e;
// if (!e.contains(k)) continue;

TRACE("dioph_eq", print_eprime_entry(e_index, tout << "before:") << std::endl;
tout << "k_coeff:" << e.get_coeff(k) << std::endl;);
// TRACE("dioph_eq", print_eprime_entry(e_index, tout << "before:") << std::endl;
// tout << "k_coeff:" << e.get_coeff(k) << std::endl;);

/*
if (!l_term.is_empty()) {
if (k_sign == 1)
add_operator(m_eprime[e_index].m_l, -k_coeff, l_term);
else
add_operator(m_eprime[e_index].m_l, k_coeff, l_term);
}
*/
m_eprime[e_index].m_l = lra.mk_join(dep, m_eprime[e_index].m_l);
e.substitute_var_with_term(k_subst, k);
TRACE("dioph_eq", print_eprime_entry(e_index, tout << "after :") << std::endl;);
}
}
// /*
// if (!l_term.is_empty()) {
// if (k_sign == 1)
// add_operator(m_eprime[e_index].m_l, -k_coeff, l_term);
// else
// add_operator(m_eprime[e_index].m_l, k_coeff, l_term);
// }
// */
// m_eprime[e_index].m_l = lra.mk_join(dep, m_eprime[e_index].m_l);
// e.substitute_var_with_term(k_subst, k);
// TRACE("dioph_eq", print_eprime_entry(e_index, tout << "after :") << std::endl;);
// }
// }

std::tuple<mpq, unsigned, int> find_minimal_abs_coeff(unsigned row_index) const {
bool first = true, first_fresh = true;
Expand Down Expand Up @@ -664,23 +654,20 @@ namespace lp {
m_e_matrix.m_rows[c.var()][c.offset()].offset() = pivot_col_cell_index;
}

unsigned f_rows_in_column =0;
for (const auto& c: column) {
if (m_eprime[c.var()].m_entry_status == entry_status::F)
f_rows_in_column ++;
}
TRACE("dioph_eq", tout << "f_rows_in_column:" << f_rows_in_column << std::endl;);
while (column.size() > 1 && f_rows_in_column > 0 ) {
auto & c = column.back();
if (m_eprime[c.var()].m_entry_status != entry_status::F)
unsigned cell_to_process = column.size() - 1;
while (cell_to_process > 0) {
auto & c = column[cell_to_process];
if (m_eprime[c.var()].m_entry_status != entry_status::F) {
cell_to_process--;
continue;
f_rows_in_column--;
}
SASSERT(c.var() != piv_row_index);
mpq coeff = m_e_matrix.get_val(c);
TRACE("dioph_eq", tout << "c_row:" << c.var(); print_e_row(c.var(), tout) << std::endl;);
m_e_matrix.pivot_row_to_row_given_cell_with_sign(piv_row_index, c, j, j_sign);
m_eprime[c.var()].m_c -= j_sign* coeff*m_eprime[piv_row_index].m_c;
TRACE("dioph_eq", tout << "after pivoting c_row:"; print_e_row(c.var(), tout) << std::endl;);
cell_to_process--;
}
}

Expand All @@ -705,7 +692,7 @@ namespace lp {
unsigned fresh_row = m_e_matrix.row_count();
m_e_matrix.add_row(); // for the fresh variable definition
m_e_matrix.add_column(); // the fresh variable itself
m_eprime.push_back({fresh_row, term_o(), nullptr, mpq(0), entry_status::S});
m_eprime.push_back({fresh_row, nullptr, mpq(0), entry_status::S});
// Add a new row for the fresh variable definition
/* Let eh = sum(ai*xi) + c. For each i != k, let ai = qi*ahk + ri, and let c = c_q * ahk + c_r.
eh = ahk*(x_k + sum{qi*xi|i != k} + c_q) + sum {ri*xi|i!= k} + c_r.
Expand All @@ -731,7 +718,7 @@ namespace lp {
}

// add entry to S
m_eprime.push_back({fresh_row, term_o(), nullptr});
m_eprime.push_back({fresh_row, nullptr, mpq(0), entry_status::S});
this->m_s.push_back(fresh_row);
TRACE("dioph_eq", tout << "changed entry:"; print_eprime_entry(e_index, tout)<< std::endl;
tout << "added to S:\n"; print_eprime_entry(m_eprime.size()-1, tout););
Expand All @@ -745,11 +732,10 @@ namespace lp {

std::ostream& print_eprime_entry(const eprime_entry& e, std::ostream& out) {
out << "{\n";
out << "\trow:" << e.m_row_index << "," << std::endl;
print_term_o(get_term_from_e_matrix(e.m_row_index), out << "\trow:");

print_term_o(get_term_from_e_matrix(e.m_row_index), out << "\trow:") << "\n";
out << "\tstatus:" << (int)e.m_entry_status;
// print_dep(out<< "\tm_l:", e.m_l) << "\n";
out << "}"<< std::endl;
out << "\n}\n";
return out;
}

Expand All @@ -774,7 +760,6 @@ namespace lp {
auto [ahk, k, k_sign] = find_minimal_abs_coeff(eprime_entry.m_row_index);
TRACE("dioph_eq", tout << "ahk:" << ahk << ", k:" << k << ", k_sign:" << k_sign << std::endl;);
if (ahk.is_one()) {
eprime_entry.m_e.j() = k;
TRACE("dioph_eq", tout << "push to S:\n"; print_eprime_entry(*eh_it, tout););
move_entry_from_f_to_s(k, eh_it);
eliminate_var_in_f(eprime_entry, k , k_sign);
Expand Down

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