Commit 1087c623 authored by Alexandre Duret-Lutz's avatar Alexandre Duret-Lutz
Browse files

Move language containment into ltl_simplifier.

* src/ltlvisit/simplify.cc: Integrate the tau03
containment rules.
* src/ltlvisit/simplify.hh: Add options to select simplifications.
* src/ltlvisit/reduce.cc (reduce): Do not call reduce_tau03().
* src/ltlvisit/contain.cc (reduce_tau03_visitor): Remove.
(reduce_tau03): Implement it using ltl_simplifier.
parent 82b42494
......@@ -22,6 +22,7 @@
// 02111-1307, USA.
#include "contain.hh"
#include "simplify.hh"
#include "tunabbrev.hh"
#include "ltlast/unop.hh"
#include "ltlast/binop.hh"
......@@ -144,271 +145,16 @@ namespace spot
}
namespace
{
struct reduce_tau03_visitor : public clone_visitor {
bool stronger;
language_containment_checker* lcc;
reduce_tau03_visitor(bool stronger,
language_containment_checker* lcc)
: stronger(stronger), lcc(lcc)
{
}
void
visit(unop* uo)
{
formula* a = recurse(uo->child());
switch (uo->op())
{
case unop::X:
// if X(a) = a, then keep only a !
if (stronger && lcc->equal(a, uo))
{
result_ = a;
break;
}
default:
result_ = unop::instance(uo->op(), a);
}
}
void
visit(binop* bo)
{
formula* a = recurse(bo->first());
formula* b = recurse(bo->second());
switch (bo->op())
{
case binop::U:
// if (a U b) => b, then keep b !
if (stronger && lcc->contained(bo, b))
{
a->destroy();
result_ = b;
}
// if a => b, then a U b = b.
else if ((!stronger) && lcc->contained(a, b))
{
a->destroy();
result_ = b;
}
// if !a => b, then a U b = Fb
else if (lcc->neg_contained(a, b))
{
a->destroy();
result_ = unop::instance(unop::F, b);
}
else
{
result_ = binop::instance(binop::U, a, b);
}
break;
case binop::W:
// if (a W b) => b, then keep b !
if (stronger && lcc->contained(bo, b))
{
a->destroy();
result_ = b;
}
// if a => b, then a W b = b.
else if ((!stronger) && lcc->contained(a, b))
{
a->destroy();
result_ = b;
}
// if !a => b, then a W b = 1
else if (lcc->neg_contained(a, b))
{
a->destroy();
b->destroy();
result_ = constant::true_instance();
}
else
{
result_ = binop::instance(binop::W, a, b);
}
break;
case binop::R:
// if b => a, then a R b = b.
if (lcc->contained(b, a))
{
a->destroy();
result_ = b;
}
// if a => !b, then a R b = Gb
else if (lcc->contained_neg(a, b))
{
a->destroy();
result_ = unop::instance(unop::G, b);
}
else
{
result_ = binop::instance(binop::R, a, b);
}
break;
case binop::M:
// if b => a, then a M b = b.
if (lcc->contained(b, a))
{
a->destroy();
result_ = b;
}
// if a => !b, then a M b = 0
else if (lcc->contained_neg(a, b))
{
a->destroy();
b->destroy();
result_ = constant::false_instance();
}
else
{
result_ = binop::instance(binop::M, a, b);
}
break;
default:
result_ = binop::instance(bo->op(), a, b);
}
}
void
visit(automatop*)
{
assert(0);
}
void
visit(multop* mo)
{
multop::vec* res = new multop::vec;
unsigned mos = mo->size();
for (unsigned i = 0; i < mos; ++i)
res->push_back(recurse(mo->nth(i)));
result_ = 0;
bool changed = false;
switch (mo->op())
{
case multop::Or:
for (unsigned i = 0; i < mos; ++i)
{
if (!(*res)[i])
continue;
for (unsigned j = i + 1; j < mos; ++j)
{
if (!(*res)[j])
continue;
// if !i => j, then i|j = true
if (lcc->neg_contained((*res)[i], (*res)[j]))
{
result_ = constant::true_instance();
goto constant_;
}
// if i => j, then i|j = j
else if (lcc->contained((*res)[i], (*res)[j]))
{
(*res)[i]->destroy();
(*res)[i] = 0;
changed = true;
break;
}
// if j => i, then i|j = i
else if (lcc->contained((*res)[j], (*res)[i]))
{
(*res)[j]->destroy();
(*res)[j] = 0;
changed = true;
}
}
}
break;
case multop::And:
for (unsigned i = 0; i < mos; ++i)
{
if (!(*res)[i])
continue;
for (unsigned j = i + 1; j < mos; ++j)
{
if (!(*res)[j])
continue;
// if i => !j, then i&j = false
if (lcc->contained_neg((*res)[i], (*res)[j]))
{
result_ = constant::false_instance();
goto constant_;
}
// if i => j, then i&j = i
else if (lcc->contained((*res)[i], (*res)[j]))
{
(*res)[j]->destroy();
(*res)[j] = 0;
changed = true;
}
// if j => i, then i&j = j
else if (lcc->contained((*res)[j], (*res)[i]))
{
(*res)[i]->destroy();
(*res)[i] = 0;
changed = true;
break;
}
}
}
break;
case multop::Concat:
case multop::Fusion:
case multop::AndNLM:
break;
}
if (changed)
{
multop::vec* nres = new multop::vec;
for (unsigned i = 0; i < mos; ++i)
if ((*res)[i])
nres->push_back((*res)[i]);
delete res;
res = nres;
}
result_ = multop::instance(mo->op(), res);
return;
constant_:
for (unsigned i = 0; i < mos; ++i)
if ((*res)[i])
(*res)[i]->destroy();
delete res;
}
formula*
recurse(formula* f)
{
if (!f->is_psl_formula())
return f->clone();
reduce_tau03_visitor v(stronger, lcc);
const_cast<formula*>(f)->accept(v);
return v.result();
}
};
}
formula*
reduce_tau03(const formula* f, bool stronger)
{
if (!f->is_psl_formula())
return f->clone();
bdd_dict b;
reduce_tau03_visitor v(stronger,
new language_containment_checker(&b,
true, true,
false, false));
// reduce_tau03_visitor does not handle Xor, Implies, and Equiv.
f = unabbreviate_ltl(f);
const_cast<formula*>(f)->accept(v);
f->destroy();
delete v.lcc;
return v.result();
ltl_simplifier_options opt(false, false, false,
true, stronger);
ltl_simplifier simpl(opt);
return simpl.simplify(f);
}
}
}
......@@ -28,7 +28,6 @@
#include "lunabbrev.hh"
#include "simpfg.hh"
#include "nenoform.hh"
#include "contain.hh"
#include "simplify.hh"
namespace spot
......@@ -73,20 +72,8 @@ namespace spot
f2->destroy();
f2 = f1;
f1 = simplifier.simplify(f2);
f = simplifier.simplify(f2);
f2->destroy();
f2 = f1;
if (opt & (Reduce_Containment_Checks
| Reduce_Containment_Checks_Stronger))
{
formula* f1 =
reduce_tau03(f2,
opt & Reduce_Containment_Checks_Stronger);
f2->destroy();
f2 = f1;
}
f = f2;
}
prev->destroy();
......
This diff is collapsed.
......@@ -31,15 +31,20 @@ namespace spot
class ltl_simplifier_options
{
public:
ltl_simplifier_options()
: reduce_basics(true),
synt_impl(true),
event_univ(true),
containment_checks(false),
containment_checks_stronger(false),
ltl_simplifier_options(bool basics = true,
bool synt_impl = true,
bool event_univ = true,
bool containment_checks = false,
bool containment_checks_stronger = false,
bool nenoform_stop_on_boolean = false)
: reduce_basics(basics),
synt_impl(synt_impl),
event_univ(event_univ),
containment_checks(containment_checks),
containment_checks_stronger(containment_checks_stronger),
// If true, Boolean subformulae will not be put into
// negative normal form.
nenoform_stop_on_boolean(false)
nenoform_stop_on_boolean(nenoform_stop_on_boolean)
{
}
......@@ -48,6 +53,8 @@ namespace spot
bool event_univ;
bool containment_checks;
bool containment_checks_stronger;
// If true, Boolean subformulae will not be put into
// negative normal form.
bool nenoform_stop_on_boolean;
};
......
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