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v1 of conflict driven optimization

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2013-11-03 19:27:06 -08:00
parent a26bd69a5e
commit 883018b405
2 changed files with 24 additions and 10 deletions
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6
src/opt/optimize_objectives.cpp
View file

@ -151,6 +151,7 @@ namespace opt {
if (m_lower[i] < m_upper[i]) {
smt::theory_var v = m_vars[i];
mid.push_back((m_upper[i]+m_lower[i])/rational(2));
//mid.push_back(m_upper[i]);
bound = th.block_upper_bound(v, mid[i]);
bounds.push_back(bound);
}
@ -164,14 +165,15 @@ namespace opt {
if (m_lower[i] <= mid[i] && mid[i] <= m_upper[i] && m_lower[i] < m_upper[i]) {
th.enable_record_conflict(bounds[i].get());
lbool is_sat = s->check_sat(1, bounds.c_ptr() + i);
th.enable_record_conflict(0);
switch(is_sat) {
case l_true:
IF_VERBOSE(2, verbose_stream() << "Setting lower bound for v" << m_vars[i] << " to " << m_upper[i] << "\n";);
m_lower[i] = mid[i];
th.enable_record_conflict(0);
update_lower();
break;
case l_false:
IF_VERBOSE(2, verbose_stream() << "conflict: " << th.conflict_minimize() << "\n";);
if (!th.conflict_minimize().get_infinity().is_zero()) {
// bounds is not in the core. The context is unsat.
m_upper[i] = m_lower[i];
@ -182,8 +184,10 @@ namespace opt {
}
break;
default:
th.enable_record_conflict(0);
return l_undef;
}
th.enable_record_conflict(0);
progress = true;
}
}

28
src/smt/theory_arith_aux.h
View file

@ -1028,7 +1028,7 @@ namespace smt {
m_atoms.push_back(a);
insert_bv2a(bv, a);
TRACE("arith", tout << mk_pp(b, m) << "\n";
display_atom(tout, a, false););
display_atom(tout, a, false););
}
return b;
}
@ -1074,6 +1074,8 @@ namespace smt {
unsigned num_params, parameter* params) {
ast_manager& m = get_manager();
context& ctx = get_context();
expr_ref tmp(m), vq(m);
expr* x, *y, *e;
if (null_bool_var == m_bound_watch) {
return;
}
@ -1088,12 +1090,20 @@ namespace smt {
if (idx == num_lits) {
return;
}
for (unsigned i = 0; i < num_lits; ++i) {
ctx.literal2expr(lits[i], tmp);
}
for (unsigned i = 0; i < num_eqs; ++i) {
enode_pair const& p = eqs[i];
x = p.first->get_owner();
y = p.second->get_owner();
tmp = m.mk_eq(x,y);
}
SASSERT(num_params == 1 + num_lits + num_eqs);
SASSERT(params[0].is_symbol());
SASSERT(params[0].get_symbol() == symbol("farkas")); // for now, just handle this rule.
farkas_util farkas(m);
expr_ref tmp(m), vq(m);
expr* x, *y, *e;
rational q;
for (unsigned i = 0; i < num_lits; ++i) {
parameter const& pa = params[i+1];
@ -1102,20 +1112,20 @@ namespace smt {
q = abs(pa.get_rational());
continue;
}
ctx.literal2expr(~lits[i], tmp);
ctx.literal2expr(lits[i], tmp);
farkas.add(abs(pa.get_rational()), to_app(tmp));
}
for (unsigned i = 0; i < num_eqs; ++i) {
enode_pair const& p = eqs[i];
x = p.first->get_owner();
y = p.second->get_owner();
tmp = m.mk_not(m.mk_eq(x,y));
tmp = m.mk_eq(x,y);
parameter const& pa = params[1 + num_lits + i];
SASSERT(pa.is_rational());
farkas.add(abs(pa.get_rational()), to_app(tmp));
}
tmp = farkas.get();
std::cout << tmp << "\n";
// IF_VERBOSE(1, verbose_stream() << "Farkas result: " << tmp << "\n";);
atom* a = get_bv2a(m_bound_watch);
SASSERT(a);
expr_ref_vector terms(m);
@ -1123,7 +1133,7 @@ namespace smt {
bool strict = false;
if (m_util.is_le(tmp, x, y) || m_util.is_ge(tmp, y, x)) {
}
else if (m_util.is_lt(tmp, x, y) || m_util.is_gt(tmp, y, x)) {
else if (m.is_not(tmp, e) && (m_util.is_le(e, y, x) || m_util.is_ge(e, x, y))) {
strict = true;
}
else if (m.is_eq(tmp, x, y)) {
@ -1132,7 +1142,7 @@ namespace smt {
UNREACHABLE();
}
e = var2expr(a->get_var());
q = -q*farkas.get_normalize_factor();
q *= farkas.get_normalize_factor();
SASSERT(!m_util.is_int(e) || q.is_int()); // TBD: not fully handled.
if (q.is_one()) {
vq = e;
@ -1146,13 +1156,13 @@ namespace smt {
}
th_rewriter rw(m);
rw(vq, tmp);
IF_VERBOSE(1, verbose_stream() << tmp << "\n";);
VERIFY(m_util.is_numeral(tmp, q));
if (m_upper_bound < q) {
m_upper_bound = q;
if (strict) {
m_upper_bound -= get_epsilon(a->get_var());
}
IF_VERBOSE(1, verbose_stream() << "new upper bound: " << m_upper_bound << "\n";);
}
}