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

* src/tgbaalgos/ltl2tgba_fm.hh (ltl_to_tgba_fm): Add argument

Browse source 
branching_postponement.
* src/tgbaalgos/ltl2tgba_fm.cc (fill_dests): New function, extracted
from ltl_to_tgba_fm().
(ltl_to_tgba_fm): Implement the branching_postponement optimization.
* src/tgbatest/ltl2tgba.cc: Add the -p option.
* src/tgbatest/spotlbtt.test: Exercise branching postponement.
* wrap/python/cgi/ltl2tgba.in: Make it an option.
This commit is contained in:
Alexandre Duret-Lutz 2004-05-07 10:00:34 +00:00
parent f11df7679a
commit 6b06e28f3d
6 changed files with 150 additions and 44 deletions
Download patch file Download diff file Expand all files Collapse all files

116
src/tgbaalgos/ltl2tgba_fm.cc
View file

@ -396,9 +396,57 @@ namespace spot
}
typedef std::map<bdd, bdd, bdd_less_than> prom_map;
typedef Sgi::hash_map<const formula*, prom_map, ptr_hash<formula> > dest_map;
typedef std::map<bdd, const formula*, bdd_less_than> succ_to_formula;
static void
fill_dests(translate_dict& d, bool symb_merge,
std::set<const formula*>& formulae_seen,
succ_to_formula& canonical_succ, ltl_trad_visitor& v,
dest_map& dests, bdd label, formula* dest)
{
// If we already know a state with the same successors,
// use it in lieu of the current one. (See the comments
// for canonical_succ.) We need to do this only for new
// destinations.
if (symb_merge
&& formulae_seen.find(dest) == formulae_seen.end())
{
dest->accept(v);
bdd succbdd = v.result();
succ_to_formula::iterator cs =
canonical_succ.find(succbdd);
if (cs != canonical_succ.end())
{
destroy(dest);
dest = clone(cs->second);
}
else
{
canonical_succ[succbdd] = clone(dest);
}
}
bdd promises = bdd_existcomp(label, d.a_set);
bdd conds = bdd_existcomp(label, d.var_set);
dest_map::iterator i = dests.find(dest);
if (i == dests.end())
{
dests[dest][promises] = conds;
}
else
{
i->second[promises] |= conds;
destroy(dest);
}
}
tgba_explicit*
ltl_to_tgba_fm(const formula* f, bdd_dict* dict,
bool exprop, bool symb_merge)
bool exprop, bool symb_merge, bool branching_postponement)
{
// Normalize the formula. We want all the negations on
// the atomic propositions. We also suppress logic
@ -414,7 +462,6 @@ namespace spot
// We do this because many formulae (such as `aR(bRc)' and
// `aR(bRc).(bRc)') are equivalent, and are trivially identified
// by looking at the set of successors.
typedef std::map<bdd, const formula*, bdd_less_than> succ_to_formula;
succ_to_formula canonical_succ;
translate_dict d(dict);
@ -435,8 +482,8 @@ namespace spot
// Translate it into a BDD to simplify it.
// FIXME: Currently the same formula can be converted into a
// BDD twice. Once in the symb_merge block below, and then
// once here.
// BDD twice. Once in the symb_merge block in fill_dests,
// and then once here.
f->accept(v);
bdd res = v.result();
succ_to_formula::iterator cs = canonical_succ.find(res);
@ -474,10 +521,6 @@ namespace spot
//
// In `exprop' mode, considering all possible combinations of
// outgoing propositions generalizes the above trick.
typedef std::map<bdd, bdd, bdd_less_than> prom_map;
typedef Sgi::hash_map<const formula*, prom_map, ptr_hash<formula> >
dest_map;
dest_map dests;
// Compute all outgoing arcs.
@ -497,50 +540,43 @@ namespace spot
bdd one_prop_set =
exprop ? bdd_satoneset(all_props, var_set, bddtrue) : bddtrue;
all_props -= one_prop_set;
typedef std::map<bdd, formula*, bdd_less_than> succ_map;
succ_map succs;
minato_isop isop(res & one_prop_set);
bdd cube;
while ((cube = isop.next()) != bddfalse)
{
const formula* dest =
bdd label = bdd_exist(cube, d.next_set);
formula* dest =
d.conj_bdd_to_formula(bdd_existcomp(cube, d.next_set));
// If we already know a state with the same successors,
// use it in lieu of the current one. (See the comments
// for canonical_succ.) We need to do this only for new
// destinations.
if (symb_merge
&& formulae_seen.find(dest) == formulae_seen.end())
// If we are not postponing the branching, we can
// declare the outgoing transitions immediately.
// Otherwise, we merge transitions with identical
// label, and declare the outgoing transitions in a
// second loop.
if (!branching_postponement)
{
dest->accept(v);
bdd succbdd = v.result();
succ_to_formula::iterator cs =
canonical_succ.find(succbdd);
if (cs != canonical_succ.end())
{
destroy(dest);
dest = clone(cs->second);
}
else
{
canonical_succ[succbdd] = clone(dest);
}
}
bdd promises = bdd_existcomp(cube, d.a_set);
bdd conds =
exprop ? one_prop_set : bdd_existcomp(cube, var_set);
dest_map::iterator i = dests.find(dest);
if (i == dests.end())
{
dests[dest][promises] = conds;
fill_dests(d, symb_merge, formulae_seen, canonical_succ,
v, dests, label, dest);
}
else
{
i->second[promises] |= conds;
destroy(dest);
succ_map::iterator si = succs.find(label);
if (si == succs.end())
succs[label] = dest;
else
si->second = multop::instance(multop::Or,
si->second, dest);
}
}
if (branching_postponement)
for (succ_map::const_iterator si = succs.begin();
si != succs.end(); ++si)
fill_dests (d, symb_merge, formulae_seen, canonical_succ, v,
dests, si->first, si->second);
}
// Check for an arc going to 1 (True). Register it first, that