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remove watch, hoist orbit to track used variables

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2020-01-02 00:39:50 -08:00
parent 1d0572354b
commit c1032c3403
6 changed files with 46 additions and 117 deletions
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51
src/math/grobner/pdd_simplifier.cpp
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@ -56,7 +56,6 @@
#include "math/grobner/pdd_simplifier.h"
#include "math/simplex/bit_matrix.h"
#include "util/uint_set.h"
namespace dd {
@ -395,34 +394,42 @@ namespace dd {
vector<pdd> eqs, simp_eqs;
for (auto* e : s.m_to_simplify) if (!e->dep()) eqs.push_back(e->poly());
for (auto* e : s.m_processed) if (!e->dep()) eqs.push_back(e->poly());
exlin_augment(eqs);
simplify_exlin(eqs, simp_eqs);
vector<uint_set> orbits(s.m.num_vars());
init_orbits(eqs, orbits);
exlin_augment(orbits, eqs);
simplify_exlin(orbits, eqs, simp_eqs);
for (pdd const& p : simp_eqs) {
s.add(p);
}
return !simp_eqs.empty() && simplify_linear_step(false);
}
/**
augment set of equations by multiplying with selected variables.
Uses orbits to prune which variables are multiplied.
TBD: could also prune added polynomials based on a maximal degree.
*/
void simplifier::exlin_augment(vector<pdd>& eqs) {
unsigned nv = s.m.num_vars();
vector<uint_set> orbits(nv);
random_gen rand(s.m_config.m_random_seed);
unsigned modest_num_eqs = std::min(eqs.size(), 500u);
unsigned max_xlin_eqs = modest_num_eqs*modest_num_eqs + eqs.size();
for (pdd p : eqs) {
void simplifier::init_orbits(vector<pdd> const& eqs, vector<uint_set>& orbits) {
for (pdd const& p : eqs) {
auto const& fv = p.free_vars();
for (unsigned i = fv.size(); i-- > 0; ) {
orbits[fv[i]].insert(fv[i]); // if v is used, it is in its own orbit.
for (unsigned j = i; j-- > 0; ) {
orbits[fv[i]].insert(fv[j]);
orbits[fv[j]].insert(fv[i]);
}
}
}
}
/**
augment set of equations by multiplying with selected variables.
Uses orbits to prune which variables are multiplied.
TBD: could also prune added polynomials based on a maximal degree.
TBD: for large systems, extract cluster of polynomials based on sampling orbits
*/
void simplifier::exlin_augment(vector<uint_set> const& orbits, vector<pdd>& eqs) {
unsigned nv = s.m.num_vars();
random_gen rand(s.m_config.m_random_seed);
unsigned modest_num_eqs = std::min(eqs.size(), 500u);
unsigned max_xlin_eqs = modest_num_eqs*modest_num_eqs + eqs.size();
TRACE("dd.solver", tout << "augment " << nv << "\n";
for (auto const& o : orbits) tout << o.num_elems() << "\n";
);
@ -435,7 +442,7 @@ namespace dd {
pdd pv = s.m.mk_var(v);
for (pdd p : eqs) {
for (unsigned w : p.free_vars()) {
if (orbitv.contains(w)) {
if (v != w && orbitv.contains(w)) {
n_eqs.push_back(pv * p);
break;
}
@ -453,7 +460,7 @@ namespace dd {
if (orbitv.empty()) continue;
pdd pv = s.m.mk_var(v);
for (unsigned w : orbitv) {
if (v > w) continue;
if (v >= w) continue;
pdd pw = s.m.mk_var(w);
for (pdd p : eqs) {
if (n_eqs.size() > max_xlin_eqs) {
@ -474,7 +481,7 @@ namespace dd {
TRACE("dd.solver", for (pdd const& p : eqs) tout << p << "\n";);
}
void simplifier::simplify_exlin(vector<pdd> const& eqs, vector<pdd>& simp_eqs) {
void simplifier::simplify_exlin(vector<uint_set> const& orbits, vector<pdd> const& eqs, vector<pdd>& simp_eqs) {
// create variables for each non-constant monomial.
u_map<unsigned> mon2idx;
@ -497,9 +504,11 @@ namespace dd {
// insert variables last.
unsigned nv = s.m.num_vars();
for (unsigned v = 0; v < nv; ++v) {
pdd r = s.m.mk_var(v);
mon2idx.insert(r.index(), idx2mon.size());
idx2mon.push_back(r);
if (!orbits[v].empty()) { // not all variables are used.
pdd r = s.m.mk_var(v);
mon2idx.insert(r.index(), idx2mon.size());
idx2mon.push_back(r);
}
}
bit_matrix bm;