alarsyo/spot
1
0
Fork 0
Code Issues Pull requests Projects Releases Wiki Activity

remove_alternation: use edge_separator

Browse source 
* spot/twaalgos/split.cc,
spot/twaalgos/split.hh (edge_separator::add_to_basis): Add a variant
that is limited in the number of labels it adds.
* spot/twaalgos/alternation.cc: Use it.  Also add
a cache of separated edges, as in the split.
This commit is contained in:
Alexandre Duret-Lutz 2024-03-18 21:19:38 +01:00
parent 3bcffa2fcd
commit c220107eb4
3 changed files with 82 additions and 33 deletions
Download patch file Download diff file Expand all files Collapse all files

85
spot/twaalgos/alternation.cc
View file

@ -21,6 +21,8 @@
#include <sstream>
#include <spot/twaalgos/alternation.hh>
#include <spot/twaalgos/sccinfo.hh>
#include <spot/twaalgos/split.hh>
#include <spot/priv/robin_hood.hh>
#include <spot/misc/minato.hh>
#include <spot/misc/bddlt.hh>
@ -389,37 +391,12 @@ namespace spot
bool will_use_labels = n_ap > 5;
if (will_use_labels)
{
std::set<bdd, bdd_less_than> all_labels;
edge_separator es;
// Gather all labels, but stop if we see too many.
// The threshold below is arbitrary.
unsigned max_labels = 100 * n_ap;
for (auto& e: aut_->edges())
{
if (all_labels.insert(e.cond).second)
if (all_labels.size() > max_labels)
{
will_use_labels = false;
break;
}
}
will_use_labels = es.add_to_basis(aut_, 256 * n_ap);
if (will_use_labels)
{
separated_labels.reserve(all_labels.size());
separated_labels.push_back(bddtrue);
for (auto& lab: all_labels)
{
// Do not use a range-based or iterator-based for loop
// here, as push_back invalidates the end iterator.
for (unsigned cur = 0, sz = separated_labels.size();
cur < sz; ++cur)
if (bdd common = separated_labels[cur] & lab;
common != bddfalse && common != separated_labels[cur])
{
separated_labels[cur] -= lab;
separated_labels.push_back(common);
}
}
}
separated_labels = es.basis();
}
// We for easier computation of outgoing sets, we will
@ -490,6 +467,19 @@ namespace spot
acc_cond::mark_t all_marks = res->acc().all_sets();
// We use a cache to avoid the costly loop around
// separated_labels.
//
// Cache entries have the form (bdd, [begin, end]) where bdd
// what should be split, and begin/end denotes a range of
// existing transition numbers that cover the split.
//
// std::pair causes some noexcept warnings when used in
// robin_hood::unordered_map with GCC 9.4. Use robin_hood::pair
// instead.
typedef robin_hood::pair<unsigned, unsigned> cached_t;
robin_hood::unordered_map<bdd, cached_t, bdd_hash> split_cond;
state_set v;
while (!todo.empty())
{
@ -547,12 +537,41 @@ namespace spot
};
if (!will_use_labels)
// Loop over all possible valuations atomic properties.
for (bdd oneletter: minterms_of(all_letters, ap))
create_edges(oneletter, bdd_restrict(bs, oneletter));
{
// Loop over all possible valuations of atomic properties.
for (bdd oneletter: minterms_of(all_letters, ap))
create_edges(oneletter, bdd_restrict(bs, oneletter));
}
else
for (bdd label: separated_labels)
create_edges(label, bdd_relprod(label, bs, res->ap_vars()));
{
auto& [begin, end] = split_cond[all_letters];
if (begin == end)
{
begin = res->num_edges() + 1;
for (bdd label: separated_labels)
create_edges(label, bdd_relprod(label, bs,
res->ap_vars()));
end = res->num_edges() + 1;
}
else
{
// We have already split all_letters once, so we
// can simply reuse the set of labels we used
// then, avoiding the iteration on
// separated_labels.
auto& g = res->get_graph();
bdd last = bddfalse;
for (unsigned i = begin; i < end; ++i)
{
bdd label = g.edge_storage(i).cond;
if (label == last)
continue;
last = label;
create_edges(label, bdd_relprod(label, bs,
res->ap_vars()));
}
}
}
}
res->merge_edges();
return res;

17
spot/twaalgos/split.cc
View file

@ -118,6 +118,23 @@ namespace spot
add_to_basis(lab);
}
bool edge_separator::add_to_basis(const const_twa_graph_ptr& aut,
unsigned long max_label)
{
std::set<bdd, bdd_less_than> all_labels;
for (auto& e: aut->edges())
{
if (all_labels.insert(e.cond).second)
if (max_label-- == 0)
return false;
}
for (bdd lab: all_labels)
add_to_basis(lab);
for (formula f: aut->ap())
aps_.insert(f);
return true;
}
twa_graph_ptr
edge_separator::separate_implying(const const_twa_graph_ptr& aut)
{

13
spot/twaalgos/split.hh
View file

@ -156,9 +156,15 @@ namespace spot
/// add_to_basis() and add a new atomic proposition, you should
/// remember to register it in the result of separate_implying()
/// or separate_compat() yourself.
///
/// If \a max_label is given, at most \a max_label unique labels
/// are added to the basis. False is returned iff the automaton
/// used more labels.
/// @{
void add_to_basis(bdd label);
void add_to_basis(const const_twa_graph_ptr& aut);
bool add_to_basis(const const_twa_graph_ptr& aut,
unsigned long max_label);
/// @}
/// \brief Separate an automaton
///
@ -200,10 +206,17 @@ namespace spot
return {basis_, label};
}
#endif
unsigned basis_size() const
{
return basis_.size();
}
const std::vector<bdd>& basis() const
{
return basis_;
}
private:
std::vector<bdd> basis_{bddtrue};
std::set<formula> aps_;