Commit c7352498 authored by Alexandre Duret-Lutz's avatar Alexandre Duret-Lutz
Browse files

Halve the number of application of eventual_universal_visitor in

reduce_visitor::visit(binop).

* src/ltlvisit/reduce.cc (eventual_universal_visitor::recurse_):
Move this method...
(recurse_eu): ... outside as a separate function.  Likewise for
the universal/eventual result struct.
(reduce_visitor::visit(binop)): Call recurse_eu() once to replace
two calls to is_eventual and is_universal, thus replacing two
recursions by one.
parent dabb7ecc
2010-12-01 Alexandre Duret-Lutz <adl@gnu.org>
Halve the number of application of eventual_universal_visitor in
reduce_visitor::visit(binop).
* src/ltlvisit/reduce.cc (eventual_universal_visitor::recurse_):
Move this method...
(recurse_eu): ... outside as a separate function. Likewise for
the universal/eventual result struct.
(reduce_visitor::visit(binop)): Call recurse_eu() once to replace
two calls to is_eventual and is_universal, thus replacing two
recursions by one.
2010-12-01 Alexandre Duret-Lutz <adl@lrde.epita.fr>
Move the eventual-universal functions where the belong.
......
......@@ -38,18 +38,20 @@ namespace spot
{
namespace
{
class eventual_universal_visitor: public const_visitor
typedef union
{
union
unsigned v;
struct is_struct
{
unsigned v;
struct is_struct
{
bool eventual:1;
bool universal:1;
} is;
} ret_;
bool eventual:1;
bool universal:1;
} is;
} eu_info;
static unsigned recurse_eu(const formula* f);
class eventual_universal_visitor: public const_visitor
{
public:
eventual_universal_visitor()
......@@ -73,6 +75,12 @@ namespace spot
return ret_.is.universal;
}
unsigned
eu() const
{
return ret_.v;
}
void
visit(const atomic_prop*)
{
......@@ -91,13 +99,13 @@ namespace spot
const formula* f1 = uo->child();
if (uo->op() == unop::F)
{
ret_.v = recurse_(f1);
ret_.v = recurse_eu(f1);
ret_.is.eventual = true;
return;
}
if (uo->op() == unop::G)
{
ret_.v = recurse_(f1);
ret_.v = recurse_eu(f1);
ret_.is.universal = true;
return;
}
......@@ -122,7 +130,7 @@ namespace spot
// This means that we can use the following case to handle
// all cases of (f U g), (f R g), (f W g), (f M g) for
// universality and eventuality.
ret_.v = recurse_(f1) & recurse_(f2);
ret_.v = recurse_eu(f1) & recurse_eu(f2);
// we are left with the case where U, R, W, or M are actually
// used to represent F or G.
......@@ -164,21 +172,23 @@ namespace spot
{
unsigned mos = mo->size();
assert(mos != 0);
ret_.v = recurse_(mo->nth(0));
ret_.v = recurse_eu(mo->nth(0));
for (unsigned i = 1; i < mos && ret_.v != 0; ++i)
ret_.v &= recurse_(mo->nth(i));
ret_.v &= recurse_eu(mo->nth(i));
}
private:
unsigned
recurse_(const formula* f)
{
eventual_universal_visitor v;
const_cast<formula*>(f)->accept(v);
return v.ret_.v;
}
eu_info ret_;
};
static unsigned
recurse_eu(const formula* f)
{
eventual_universal_visitor v;
const_cast<formula*>(f)->accept(v);
return v.eu();
}
/////////////////////////////////////////////////////////////////////////
......@@ -257,15 +267,14 @@ namespace spot
binop::type op = bo->op();
formula* f2 = recurse(bo->second());
bool f2_eventual = false;
eu_info f2i = { recurse_eu(f2) };
if (opt_ & Reduce_Eventuality_And_Universality)
{
f2_eventual = is_eventual(f2);
/* If b is a pure eventuality formula then a U b = b.
If b is a pure universality formula a R b = b. */
if ((f2_eventual && (op == binop::U))
|| (is_universal(f2) && (op == binop::R)))
if ((f2i.is.eventual && (op == binop::U))
|| (f2i.is.universal && (op == binop::R)))
{
result_ = f2;
return;
......@@ -273,16 +282,17 @@ namespace spot
}
formula* f1 = recurse(bo->first());
eu_info f1i = { recurse_eu(f1) };
if (opt_ & Reduce_Eventuality_And_Universality)
{
/* If a&b is a pure eventuality formula then a M b = a & b.
If a is a pure universality formula a W b = a|b. */
if (is_eventual(f1) && f2_eventual && (op == binop::M))
if (f1i.is.eventual && f2i.is.eventual && (op == binop::M))
{
result_ = multop::instance(multop::And, f1, f2);
return;
}
if (is_universal(f1) && (op == binop::W))
if (f1i.is.universal && (op == binop::W))
{
result_ = multop::instance(multop::Or, f1, f2);
return;
......
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