whytofly
/
qt6-bb10
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

QSlotObjectBase: re-enable tail-call optimisation in impl() 

Two of the three operations in impl() return void, among them the
most common one, call(). Having impl() return bool prevents tail-
call optimisations for these.

Fix by passing the bool return value for Compare as an out-parameter.

Results in a nice decrease in text size
(GCC 4.8-pre -O2 -std=c++11, stripped):

   text    data     bss     dec     hex filename
 507343   13984      48  521375   7f49f tst_qobject (old)
 505551   13984      48  519583   7ed9f tst_qobject (new)

Reported-by: Thiago Macieira <thiago.macieira@intel.com>

Change-Id: I7538c5b3f0992970c089e44f07244e6b62794a1d
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>
bb10
Marc Mutz 2012-08-15 16:42:06 +02:00 committed by Qt by Nokia
parent 04c286ceb6
commit 15b5b28425
1 changed files with 19 additions and 19 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

38
src/corelib/kernel/qobject_impl.h
View File

@ -113,13 +113,13 @@ namespace QtPrivate {
NumOperations
};
typedef bool (*ImplFn)(int which, QSlotObjectBase* this_, QObject *receiver, void **args);
typedef void (*ImplFn)(int which, QSlotObjectBase* this_, QObject *receiver, void **args, bool *ret);
const ImplFn impl;
explicit QSlotObjectBase(ImplFn fn) : ref(1), impl(fn) {} // ### make constexpr once QAtomicInt's ctor is, too
inline void destroy() { impl(Destroy, this, 0, 0); }
inline bool compare(void **a) { return impl(Compare, this, 0, a); }
inline void call(QObject *r, void **a) { impl(Call, this, r, a); }
inline void destroy() { impl(Destroy, this, 0, 0, 0); }
inline bool compare(void **a) { bool ret; impl(Compare, this, 0, a, &ret); return ret; }
inline void call(QObject *r, void **a) { impl(Call, this, r, a, 0); }
protected:
~QSlotObjectBase() {}
};
@ -129,20 +129,20 @@ namespace QtPrivate {
{
typedef QtPrivate::FunctionPointer<Func> FuncType;
Func function;
static bool impl(int which, QSlotObjectBase *this_, QObject *r, void **a)
static void impl(int which, QSlotObjectBase *this_, QObject *r, void **a, bool *ret)
{
switch (which) {
case Destroy:
delete static_cast<QSlotObject*>(this_);
return true;
break;
case Call:
FuncType::template call<Args, R>(static_cast<QSlotObject*>(this_)->function, static_cast<typename FuncType::Object *>(r), a);
return true;
break;
case Compare:
return *reinterpret_cast<Func *>(a) == static_cast<QSlotObject*>(this_)->function;
*ret = *reinterpret_cast<Func *>(a) == static_cast<QSlotObject*>(this_)->function;
break;
case NumOperations: ;
}
return false;
}
public:
explicit QSlotObject(Func f) : QSlotObjectBase(&impl), function(f) {}
@ -153,20 +153,20 @@ namespace QtPrivate {
{
typedef QtPrivate::FunctionPointer<Func> FuncType;
Func function;
static bool impl(int which, QSlotObjectBase *this_, QObject *r, void **a)
static void impl(int which, QSlotObjectBase *this_, QObject *r, void **a, bool *ret)
{
switch (which) {
case Destroy:
delete static_cast<QStaticSlotObject*>(this_);
return true;
break;
case Call:
FuncType::template call<Args, R>(static_cast<QStaticSlotObject*>(this_)->function, r, a);
return true;
break;
case Compare:
return false; // not implemented
*ret = false; // not implemented
break;
case NumOperations: ;
}
return false;
}
public:
explicit QStaticSlotObject(Func f) : QSlotObjectBase(&impl), function(f) {}
@ -178,20 +178,20 @@ namespace QtPrivate {
{
typedef QtPrivate::Functor<Func, N> FuncType;
Func function;
static bool impl(int which, QSlotObjectBase *this_, QObject *r, void **a)
static void impl(int which, QSlotObjectBase *this_, QObject *r, void **a, bool *ret)
{
switch (which) {
case Destroy:
delete static_cast<QFunctorSlotObject*>(this_);
return true;
break;
case Call:
FuncType::template call<Args, R>(static_cast<QFunctorSlotObject*>(this_)->function, r, a);
return true;
break;
case Compare:
return false; // not implemented
*ret = false; // not implemented
break;
case NumOperations: ;
}
return false;
}
public:
explicit QFunctorSlotObject(const Func &f) : QSlotObjectBase(&impl), function(f) {}