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safra: Add stutter-invarience optimisation

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* spot/twaalgos/safra.cc, spot/twaalgos/safra.hh: Here.
* tests/core/safra.cc: Add option.
This commit is contained in:
Alexandre Lewkowicz 2016-02-05 15:42:22 +01:00 • committed by Alexandre Duret-Lutz
parent 1d68decaca
commit cd71286fb5
3 changed files with 61 additions and 11 deletions
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56
spot/twaalgos/safra.cc
View file

@ -240,15 +240,44 @@ safra_state::compute_succs(const const_twa_graph_ptr& aut,
std::unordered_map<bdd, unsigned, bdd_hash>& bdd2num,
std::vector<bdd>& all_bdds,
bool scc_opt,
bool use_bisimulation) const
bool use_bisimulation,
bool use_stutter) const
{
for (auto& ap: all_bdds)
{
safra_state ss = compute_succ(aut, ap, scc, implications, is_connected,
scc_opt, use_bisimulation);
safra_state ss = *this;
if (use_stutter && aut->prop_stutter_invariant())
{
std::vector<color_t> colors;
unsigned int counter = 0;
std::map<safra_state, unsigned int> safra2id;
bool stop = false;
while (!stop)
{
auto pair = safra2id.insert({ss, counter++});
// insert should never fail
assert(pair.second);
ss = ss.compute_succ(aut, ap, scc, implications, is_connected,
scc_opt, use_bisimulation);
colors.push_back(ss.color_);
stop = safra2id.find(ss) != safra2id.end();
}
// Add color of final transition that loops back
colors.push_back(ss.color_);
unsigned int loop_start = safra2id[ss];
for (auto& min: safra2id)
{
if (min.second >= loop_start && ss < min.first)
ss = min.first;
}
ss.color_ = *std::min_element(colors.begin(), colors.end());
}
else
ss = compute_succ(aut, ap, scc, implications, is_connected,
scc_opt, use_bisimulation);
unsigned bdd_idx = bdd2num[ap];
res.emplace_back(ss, bdd_idx);
}
}
@ -455,6 +484,18 @@ safra_state::compute_succs(const const_twa_graph_ptr& aut,
bool
safra_state::operator<(const safra_state& other) const
{
if (nodes_ == other.nodes_)
{
for (auto& n: nodes_)
{
auto it = other.nodes_.find(n.first);
assert(it != other.nodes_.end());
if (nesting_cmp(n.second, it->second))
return true;
}
return false;
}
return nodes_ < other.nodes_;
}
@ -487,7 +528,7 @@ safra_state::compute_succs(const const_twa_graph_ptr& aut,
twa_graph_ptr
tgba_determinisation(const const_twa_graph_ptr& a, bool bisimulation,
bool pretty_print, bool scc_opt, bool use_bisimulation,
bool complete)
bool complete, bool use_stutter)
{
// Degeneralize
twa_graph_ptr aut = spot::degeneralize_tba(a);
@ -569,11 +610,12 @@ safra_state::compute_succs(const const_twa_graph_ptr& aut,
unsigned src_num = seen.find(curr)->second;
todo.pop_front();
curr.compute_succs(aut, succs, scc, implications, is_connected,
bdd2num, num2bdd, scc_opt, use_bisimulation);
bdd2num, num2bdd, scc_opt, use_bisimulation,
use_stutter);
for (auto s: succs)
{
// Don't construct sink state as complete does a better job at this
if (s.first.nodes_.size() == 0)
if (s.first.nodes_.empty())
continue;
auto i = seen.find(s.first);
unsigned dst_num;

6
spot/twaalgos/safra.hh
View file

@ -63,7 +63,8 @@ namespace spot
std::unordered_map<bdd, unsigned, bdd_hash>& bdd2num,
std::vector<bdd>& all_bdds,
bool scc_opt,
bool use_bisimulation) const;
bool use_bisimulation,
bool use_stutter) const;
// Compute successor for transition ap
safra_state
compute_succ(const const_twa_graph_ptr& aut,
@ -107,5 +108,6 @@ namespace spot
bool pretty_print = false,
bool scc_opt = false,
bool use_bisimulation = false,
bool complete = false);
bool complete = false,
bool use_stutter = false);
}

10
tests/core/safra.cc
View file

@ -41,6 +41,9 @@ int help()
std::cerr << "\t-H\toutput hoa format\n";
std::cerr << "\t-b\treduce result using bisimulation\n";
std::cerr << "\t--scc_opt\tUse an SCC-based Safra\n";
std::cerr << "\t--bisim_opt\tUse Simulation info to reduce macro-states "
"size\n";
std::cerr << "\t--stutter\tStutter-invarience optimisation\n";
return 1;
}
@ -55,6 +58,7 @@ int main(int argc, char* argv[])
bool out_hoa = false;
bool pretty_print = false;
bool complete = false;
bool use_stutter = false;
char* input = nullptr;
if (argc <= 2)
@ -90,6 +94,8 @@ int main(int argc, char* argv[])
scc_opt = true;
else if (!strncmp(argv[i], "--bisim_opt", 10))
use_bisim = true;
else if (!strncmp(argv[i], "--stutter", 9))
use_stutter = true;
else
{
std::cerr << "Warning: " << argv[i] << " not used\n";
@ -112,7 +118,7 @@ int main(int argc, char* argv[])
trans.set_pref(spot::postprocessor::Deterministic);
auto tmp = trans.run(f);
res = spot::tgba_determinisation(tmp, sim, pretty_print, scc_opt,
use_bisim, complete);
use_bisim, complete, use_stutter);
}
else if (in_hoa)
{
@ -120,7 +126,7 @@ int main(int argc, char* argv[])
if (aut->format_errors(std::cerr))
return 2;
res = tgba_determinisation(aut->aut, sim, pretty_print, scc_opt,
use_bisim, complete);
use_bisim, complete, use_stutter);
}
res->merge_edges();