Commit b762f542 authored by Alexandre Duret-Lutz's avatar Alexandre Duret-Lutz
Browse files

remfin: do not clone transitions that are accepting in main

* spot/twaalgos/remfin.cc (default_strategy): Detect transitions
from the main copy that are completely accepting and that do not
need to be repeated in the clones.
* tests/python/remfin.py: Add a test case.
* tests/core/ltl2dstar4.test: Improve expected results.
* NEWS: Mention the change.
parent c005041e
......@@ -32,6 +32,9 @@ New in spot 2.9.0.dev (not yet released)
spot::translator class when creating deterministic automata with
generic acceptance.
- remove_fin() learned a trick to remove some superfluous
transitions.
Bugs fixed:
- Work around undefined behavior reported by clang 10.0.0's UBsan.
......
......@@ -667,6 +667,20 @@ namespace spot
trace << "main_sets " << main_sets << "\nmain_add "
<< main_add << '\n';
// If the SCC is rejecting, there is no need for clone.
// Pretend we don't interesect any Fin.
if (si.is_rejecting_scc(n))
intersects_fin = false;
// Edges that are already satisfying the acceptance of the
// main copy do not need to be duplicated in the clones, so
// we fill allacc_edge to remember those. Of course this is
// only needed if the main copy can be accepting and if we
// will create clones.
std::vector<bool> allacc_edge(aut->edge_vector().size(), false);
auto main_acc = res->acc().restrict_to(main_sets | main_add);
bool check_main_acc = intersects_fin && !main_acc.is_f();
// Create the main copy
for (auto s: states)
for (auto& t: aut->out(s))
......@@ -675,11 +689,14 @@ namespace spot
if (sbacc || SPOT_LIKELY(si.scc_of(t.dst) == n))
a = (t.acc & main_sets) | main_add;
res->new_edge(s, t.dst, t.cond, a);
// remember edges that are completely accepting
if (check_main_acc && main_acc.accepting(a))
allacc_edge[aut->edge_number(t)] = true;
}
// We do not need any other copy if the SCC is non-accepting,
// of if it does not intersect any Fin.
if (!intersects_fin || si.is_rejecting_scc(n))
if (!intersects_fin)
continue;
// Create clones
......@@ -698,7 +715,12 @@ namespace spot
auto ns = state_map[s];
for (auto& t: aut->out(s))
{
if ((t.acc & r) || si.scc_of(t.dst) != n)
if ((t.acc & r) || si.scc_of(t.dst) != n
// edges that are already accepting in the
// main copy need not be copied in the
// clone, since cycles going through them
// are already accepted.
|| allacc_edge[aut->edge_number(t)])
continue;
auto nd = state_map[t.dst];
res->new_edge(ns, nd, t.cond, (t.acc & k) | a);
......
#!/bin/sh
# -*- coding: utf-8 -*-
# Copyright (C) 2013, 2014, 2015, 2017 Laboratoire de Recherche et
# Copyright (C) 2013-2015, 2017, 2020 Laboratoire de Recherche et
# Développement de l'Epita (LRDE).
#
# This file is part of Spot, a model checking library.
......@@ -34,7 +34,7 @@ ltlfilt -f '(GFa -> GFb) & (GFc -> GFd)' -l |
ltl2dstar --ltl2nba=spin:ltl2tgba@-s $STR - - |
autfilt --tgba --stats '%S %E %A %s %e %t %a %d' |
tee out
test "`cat out`" = '9 144 4 25 149 416 2 0'
test "`cat out`" = '9 144 4 18 98 202 2 0'
ltlfilt -f '(GFa -> GFb) & (GFc -> GFd)' -l |
ltl2dstar --ltl2nba=spin:ltl2tgba@-s $STR - - |
......
# -*- mode: python; coding: utf-8 -*-
# Copyright (C) 2015-2018 Laboratoire de Recherche et Développement
# de l'Epita
# Copyright (C) 2015-2018, 2020 Laboratoire de Recherche et Développement de
# l'Epita
#
# This file is part of Spot, a model checking library.
#
......@@ -67,3 +67,29 @@ assert(a.prop_universal().is_maybe())
assert(a.prop_unambiguous().is_maybe())
assert(a.is_deterministic() == True)
assert(a.is_unambiguous() == True)
a = spot.automaton("""
HOA: v1
States: 3
Start: 0
AP: 2 "a" "b"
acc-name: Buchi
Acceptance: 5 Inf(0)&Fin(4) | Inf(2)&Inf(3) | Inf(1)
--BODY--
State: 0 {3}
[t] 0
[0] 1 {1}
[!0] 2 {0 4}
State: 1 {3}
[1] 0
[0&1] 1 {0}
[!0&1] 2 {2 4}
State: 2
[!1] 0
[0&!1] 1 {0}
[!0&!1] 2 {0 4}
--END--
""")
b = spot.remove_fin(a)
size = (b.num_states(), b.num_edges())
assert size == (5, 17);
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