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fix solve bug

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2018-06-04 14:23:46 -07:00 • committed by Arie Gurfinkel
parent 3178f7f86d
commit fee7828b51
2 changed files with 68 additions and 36 deletions
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100
src/math/simplex/model_based_opt.cpp
View file

@ -175,8 +175,7 @@ namespace opt {
rational new_x_val;
rational x_coeff, eps(0);
vector<var> const& vars = r.m_vars;
for (unsigned j = 0; j < vars.size(); ++j) {
var const& v = vars[j];
for (var const& v : vars) {
if (x == v.m_id) {
x_coeff = v.m_coeff;
}
@ -227,8 +226,7 @@ namespace opt {
--i;
unsigned x = bound_vars[i];
unsigned_vector const& row_ids = m_var2row_ids[x];
for (unsigned j = 0; j < row_ids.size(); ++j) {
unsigned row_id = row_ids[j];
for (unsigned row_id : row_ids) {
row & r = m_rows[row_id];
r.m_value = get_row_value(r);
SASSERT(invariant(row_id, r));
@ -368,7 +366,7 @@ namespace opt {
tout << a1 << " " << a2 << ": ";
display(tout, m_rows[row_dst]);
display(tout, m_rows[row_src]););
if (a1.is_pos() != a2.is_pos()) {
if (a1.is_pos() != a2.is_pos() || m_rows[row_src].m_type == opt::t_eq) {
mul_add(x, a1, row_src, a2, row_dst);
}
else {
@ -384,6 +382,18 @@ namespace opt {
}
}
void model_based_opt::solve(unsigned row_src, rational const& a1, unsigned row_dst, unsigned x) {
SASSERT(a1 == get_coefficient(row_src, x));
SASSERT(a1.is_pos());
SASSERT(row_src != row_dst);
SASSERT(m_rows[row_src].m_type == t_eq);
if (!m_rows[row_dst].m_alive) return;
rational a2 = get_coefficient(row_dst, x);
mul(row_dst, a1);
mul_add(false, row_dst, -a2, row_src);
SASSERT(get_coefficient(row_dst, x).is_zero());
}
// resolution for integer rows.
void model_based_opt::mul_add(
unsigned x, rational const& src_c, unsigned row_src, rational const& dst_c, unsigned row_dst) {
@ -457,8 +467,8 @@ namespace opt {
}
void model_based_opt::mk_coeffs_without(vector<var>& dst, vector<var> const src, unsigned x) {
for (unsigned i = 0; i < src.size(); ++i) {
if (src[i].m_id != x) dst.push_back(src[i]);
for (var const & v : src) {
if (v.m_id != x) dst.push_back(v);
}
}
@ -469,8 +479,8 @@ namespace opt {
void model_based_opt::mul(unsigned dst, rational const& c) {
if (c.is_one()) return;
row& r = m_rows[dst];
for (unsigned i = 0; i < r.m_vars.size(); ++i) {
r.m_vars[i].m_coeff *= c;
for (auto & v : r.m_vars) {
v.m_coeff *= c;
}
r.m_coeff *= c;
r.m_value *= c;
@ -674,8 +684,8 @@ namespace opt {
unsigned dst = new_row();
row const& r = m_rows[src];
set_row(dst, r.m_vars, r.m_coeff, r.m_mod, r.m_type);
for (unsigned i = 0; i < r.m_vars.size(); ++i) {
m_var2row_ids[r.m_vars[i].m_id].push_back(dst);
for (auto const& v : r.m_vars) {
m_var2row_ids[v.m_id].push_back(dst);
}
SASSERT(invariant(dst, m_rows[dst]));
return dst;
@ -692,8 +702,8 @@ namespace opt {
void model_based_opt::add_constraint(vector<var> const& coeffs, rational const& c, rational const& m, ineq_type rel) {
unsigned row_id = new_row();
set_row(row_id, coeffs, c, m, rel);
for (unsigned i = 0; i < coeffs.size(); ++i) {
m_var2row_ids[coeffs[i].m_id].push_back(row_id);
for (var const& coeff : coeffs) {
m_var2row_ids[coeff.m_id].push_back(row_id);
}
SASSERT(invariant(row_id, m_rows[row_id]));
}
@ -703,9 +713,9 @@ namespace opt {
}
void model_based_opt::get_live_rows(vector<row>& rows) {
for (unsigned i = 0; i < m_rows.size(); ++i) {
if (m_rows[i].m_alive) {
rows.push_back(m_rows[i]);
for (row const& r : m_rows) {
if (r.m_alive) {
rows.push_back(r);
}
}
}
@ -742,9 +752,9 @@ namespace opt {
glb_rows.reset();
mod_rows.reset();
bool lub_is_unit = false, glb_is_unit = false;
unsigned eq_row = UINT_MAX;
// select the lub and glb.
for (unsigned i = 0; i < row_ids.size(); ++i) {
unsigned row_id = row_ids[i];
for (unsigned row_id : row_ids) {
if (visited.contains(row_id)) {
continue;
}
@ -758,8 +768,8 @@ namespace opt {
continue;
}
if (r.m_type == t_eq) {
solve_for(row_id, x);
return;
eq_row = row_id;
continue;
}
if (r.m_type == t_mod) {
mod_rows.push_back(row_id);
@ -795,6 +805,11 @@ namespace opt {
solve_mod(x, mod_rows);
return;
}
if (eq_row != UINT_MAX) {
solve_for(eq_row, x);
return;
}
unsigned lub_size = lub_rows.size();
unsigned glb_size = glb_rows.size();
@ -803,8 +818,7 @@ namespace opt {
// There are only upper or only lower bounds.
if (row_index == UINT_MAX) {
for (unsigned i = 0; i < glb_rows.size(); ++i) {
unsigned row_id = glb_rows[i];
for (unsigned row_id : glb_rows) {
SASSERT(m_rows[row_id].m_alive);
SASSERT(!get_coefficient(row_id, x).is_zero());
retire_row(row_id);
@ -839,8 +853,7 @@ namespace opt {
// General case.
rational coeff = get_coefficient(row_index, x);
for (unsigned i = 0; i < glb_rows.size(); ++i) {
unsigned row_id = glb_rows[i];
for (unsigned row_id : glb_rows) {
if (row_id != row_index) {
resolve(row_index, coeff, row_id, x);
}
@ -866,8 +879,8 @@ namespace opt {
void model_based_opt::solve_mod(unsigned x, unsigned_vector const& mod_rows) {
SASSERT(!mod_rows.empty());
rational D(1);
for (unsigned i = 0; i < mod_rows.size(); ++i) {
D = lcm(D, m_rows[mod_rows[i]].m_mod);
for (unsigned idx : mod_rows) {
D = lcm(D, m_rows[idx].m_mod);
}
if (D.is_zero()) {
throw default_exception("modulo 0 is not defined");
@ -876,9 +889,9 @@ namespace opt {
rational val_x = m_var2value[x];
rational u = mod(val_x, D);
SASSERT(u.is_nonneg() && u < D);
for (unsigned i = 0; i < mod_rows.size(); ++i) {
replace_var(mod_rows[i], x, u);
SASSERT(invariant(mod_rows[i], m_rows[mod_rows[i]]));
for (unsigned idx : mod_rows) {
replace_var(idx, x, u);
SASSERT(invariant(idx, m_rows[idx]));
}
//
// update inequalities such that u is added to t and
@ -894,8 +907,7 @@ namespace opt {
unsigned y = add_var(new_val, true);
unsigned_vector const& row_ids = m_var2row_ids[x];
uint_set visited;
for (unsigned i = 0; i < row_ids.size(); ++i) {
unsigned row_id = row_ids[i];
for (unsigned row_id : row_ids) {
if (!visited.contains(row_id)) {
// x |-> D*y + u
replace_var(row_id, x, D, y, u);
@ -954,23 +966,39 @@ namespace opt {
SASSERT(!a.is_zero());
SASSERT(m_rows[row_id1].m_type == t_eq);
SASSERT(m_rows[row_id1].m_alive);
if (m_var2is_int[x] && !abs(a).is_one()) {
if (a.is_neg()) {
a.neg();
m_rows[row_id1].neg();
}
SASSERT(a.is_pos());
if (m_var2is_int[x] && !a.is_one()) {
row& r1 = m_rows[row_id1];
vector<var> coeffs;
mk_coeffs_without(coeffs, r1.m_vars, x);
rational c = r1.m_coeff;
add_divides(coeffs, c, abs(a));
add_divides(coeffs, c, a);
}
unsigned_vector const& row_ids = m_var2row_ids[x];
uint_set visited;
visited.insert(row_id1);
for (unsigned i = 0; i < row_ids.size(); ++i) {
unsigned row_id2 = row_ids[i];
for (unsigned row_id2 : row_ids) {
if (!visited.contains(row_id2)) {
visited.insert(row_id2);
b = get_coefficient(row_id2, x);
if (!b.is_zero()) {
resolve(row_id1, a, row_id2, x);
row& dst = m_rows[row_id2];
switch (dst.m_type) {
case t_eq:
case t_lt:
case t_le:
solve(row_id1, a, row_id2, x);
break;
case t_mod:
// mod reduction already done.
UNREACHABLE();
break;
}
}
}
}

4
src/math/simplex/model_based_opt.h
View file

@ -58,6 +58,8 @@ namespace opt {
rational m_value; // value of m_vars + m_coeff under interpretation of m_var2value.
bool m_alive; // rows can be marked dead if they have been processed.
void reset() { m_vars.reset(); m_coeff.reset(); m_value.reset(); }
void neg() { for (var & v : m_vars) v.m_coeff.neg(); m_coeff.neg(); m_value.neg(); }
};
private:
@ -85,6 +87,8 @@ namespace opt {
void resolve(unsigned row_src, rational const& a1, unsigned row_dst, unsigned x);
void solve(unsigned row_src, rational const& a1, unsigned row_dst, unsigned x);
void mul_add(bool same_sign, unsigned row_id1, rational const& c, unsigned row_id2);
void mul_add(unsigned x, rational const& a1, unsigned row_src, rational const& a2, unsigned row_dst);