mirrors/z3
3
0
Fork 0
mirror of https://github.com/Z3Prover/z3 synced 2025-04-23 09:05:31 +00:00
Code Activity

add DDNF based engine

Browse source 
Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2014-08-21 18:04:46 -07:00
parent 8822bc1755
commit b596828d23
11 changed files with 761 additions and 11 deletions
Download patch file Download diff file Expand all files Collapse all files

52
src/opt/maxres.cpp
View file

@ -82,6 +82,7 @@ private:
expr_ref_vector m_trail;
strategy_t m_st;
rational m_max_upper;
bool m_hill_climb;
public:
maxres(context& c,
@ -92,7 +93,8 @@ public:
m_mus(m_s, m),
m_mss(m_s, m),
m_trail(m),
m_st(st)
m_st(st),
m_hill_climb(true)
{
}
@ -299,7 +301,21 @@ public:
TRACE("opt",
display_vec(tout << "core: ", core.size(), core.c_ptr());
display_vec(tout << "assumptions: ", asms.size(), asms.c_ptr()););
is_sat = s().check_sat(asms.size(), asms.c_ptr());
if (m_hill_climb) {
/**
Give preference to cores that have large minmal values.
*/
sort_assumptions(asms);
unsigned index = 0;
while (index < asms.size() && is_sat != l_false) {
index = next_index(asms, index);
is_sat = s().check_sat(index, asms.c_ptr());
}
}
else {
is_sat = s().check_sat(asms.size(), asms.c_ptr());
}
}
TRACE("opt",
tout << "num cores: " << cores.size() << "\n";
@ -315,6 +331,36 @@ public:
}
struct compare_asm {
maxres& mr;
compare_asm(maxres& mr):mr(mr) {}
bool operator()(expr* a, expr* b) const {
return mr.get_weight(a) > mr.get_weight(b);
}
};
void sort_assumptions(expr_ref_vector& _asms) {
compare_asm comp(*this);
ptr_vector<expr> asms(_asms.size(), _asms.c_ptr());
expr_ref_vector trail(_asms);
std::sort(asms.begin(), asms.end(), comp);
_asms.reset();
_asms.append(asms.size(), asms.c_ptr());
DEBUG_CODE(
for (unsigned i = 0; i + 1 < asms.size(); ++i) {
SASSERT(get_weight(asms[i]) >= get_weight(asms[i+1]));
});
}
unsigned next_index(expr_ref_vector const& asms, unsigned index) {
if (index < asms.size()) {
rational w = get_weight(asms[index]);
++index;
for (; index < asms.size() && w == get_weight(asms[index]); ++index);
}
return index;
}
lbool process_sat(ptr_vector<expr>& corr_set) {
expr_ref fml(m), tmp(m);
TRACE("opt", display_vec(tout << "corr_set: ", corr_set.size(), corr_set.c_ptr()););
@ -379,7 +425,7 @@ public:
return l_true;
}
rational get_weight(expr* e) {
rational get_weight(expr* e) const {
return m_asm2weight.find(e);
}