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cheap_eqs - work on fixed_phase

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Signed-off-by: Lev Nachmanson <levnach@hotmail.com>
This commit is contained in:
Lev Nachmanson 2020-07-02 11:51:49 -07:00
parent a1c5cff541
commit 1695379dc9
1 changed files with 21 additions and 27 deletions
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48
src/math/lp/lp_bound_propagator.h
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@ -79,8 +79,17 @@ class lp_bound_propagator {
map<mpq, vertex*, obj_hash<mpq>, default_eq<mpq>> m_vals_to_verts;
// a pair (o, j) belongs to m_vals_to_verts_neg iff -x[j] = x[m_root->column()] + o
map<mpq, vertex*, obj_hash<mpq>, default_eq<mpq>> m_vals_to_verts_neg;
// x[m_root->column()] - m_pol[j]*x[j] == const;
u_map<int> m_pol;
// x[m_root->column()] - m_pol[j].pol()*x[j] == const;
// to bind polarity and the vertex in the table
struct pol_vert {
int m_polarity;
const vertex* m_v;
pol_vert() {}
pol_vert(int p, const vertex* v): m_polarity(p), m_v(v) {}
int pol() const { return m_polarity; }
const vertex* v() const { return m_v; }
};
u_map<pol_vert> m_pol;
// if m_pos.contains(j) then x[j] = x[m_root->column()] + o
uint_set m_pos;
@ -205,22 +214,23 @@ public:
// pol for polarity
int pol(const vertex* v) const { return pol(v->column()); }
int pol(unsigned j) const { return m_pol[j]; }
void set_polarity(unsigned j, int p) {
int pol(unsigned j) const { return m_pol[j].pol(); }
void set_polarity(const vertex* v, int p) {
SASSERT(p == 1 || p == -1);
unsigned j = v->column();
SASSERT(!m_pol.contains(j));
m_pol.insert(j, p);
m_pol.insert(j, pol_vert(p, v));
}
void check_polarity(vertex* v, int polarity) {
int prev_pol;
pol_vert prev_pol;
if (!m_pol.find(v->column(), prev_pol)) {
m_pol.insert(v->column(), polarity);
set_polarity(v, polarity);
return;
}
if (prev_pol == polarity)
if (prev_pol.pol() == polarity)
return;
const vertex *u = find_other_vertex_with_same_column(v);
const vertex *u = prev_pol.v();
// we have a path L between u and v with p(L) = -1, that means we can
// create an equality of the form x + x = a, where x = v->column() = u->column()
ptr_vector<const vertex> path;
@ -234,22 +244,6 @@ public:
});
}
const vertex* find_other_vertex_with_same_column(const vertex* t) const {
return find_other_vertex_with_same_column_under(m_root, t);
}
const vertex * find_other_vertex_with_same_column_under(const vertex* v, const vertex* t) const {
if (v != t && v->column() == t->column())
return v;
for (const vertex* c : v->children()) {
auto u = find_other_vertex_with_same_column_under(c, t);
if (u)
return u;
}
UNREACHABLE();
return nullptr;
}
bool tree_contains(vertex *v) const {
if (!m_root)
@ -277,14 +271,14 @@ public:
}
const mpq& r = val(x);
m_root = alloc_v(row_index, x);
set_polarity(x, 1);
set_polarity(m_root, 1);
if (not_set(y)) {
set_fixed_vertex(m_root);
explain_fixed_in_row(row_index, m_fixed_vertex_explanation);
} else {
vertex *v = alloc_v(row_index, y);
m_root->add_child(v);
set_polarity(y, polarity);
set_polarity(v, polarity);
}
// keep root in the positive table
m_vals_to_verts.insert(r, m_root);