| Message ID | 20231223220432.712093-7-kmatsui@gcc.gnu.org |
|---|---|
| State | New |
| Headers | show |
| Series | Optimize more type traits | expand |
On Sat, 23 Dec 2023, Ken Matsui wrote: > This patch optimizes the compilation performance of std::is_pointer > by dispatching to the new __is_pointer built-in trait. > > libstdc++-v3/ChangeLog: > > * include/bits/cpp_type_traits.h (__is_pointer): Use > __is_pointer built-in trait. Optimize its implementation. > * include/std/type_traits (is_pointer): Likewise. > (is_pointer_v): Likewise. > > Co-authored-by: Jonathan Wakely <jwakely@redhat.com> > Signed-off-by: Ken Matsui <kmatsui@gcc.gnu.org> > --- > libstdc++-v3/include/bits/cpp_type_traits.h | 29 ++++++++++++++ > libstdc++-v3/include/std/type_traits | 44 +++++++++++++++++---- > 2 files changed, 65 insertions(+), 8 deletions(-) > > diff --git a/libstdc++-v3/include/bits/cpp_type_traits.h b/libstdc++-v3/include/bits/cpp_type_traits.h > index 4312f32a4e0..c348df97f72 100644 > --- a/libstdc++-v3/include/bits/cpp_type_traits.h > +++ b/libstdc++-v3/include/bits/cpp_type_traits.h > @@ -363,6 +363,13 @@ __INT_N(__GLIBCXX_TYPE_INT_N_3) > // > // Pointer types > // > +#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_pointer) > + template<typename _Tp, bool _IsPtr = __is_pointer(_Tp)> > + struct __is_pointer : __truth_type<_IsPtr> > + { > + enum { __value = _IsPtr }; > + }; > +#else > template<typename _Tp> > struct __is_pointer > { > @@ -377,6 +384,28 @@ __INT_N(__GLIBCXX_TYPE_INT_N_3) > typedef __true_type __type; > }; > > + template<typename _Tp> > + struct __is_pointer<_Tp* const> > + { > + enum { __value = 1 }; > + typedef __true_type __type; > + }; > + > + template<typename _Tp> > + struct __is_pointer<_Tp* volatile> > + { > + enum { __value = 1 }; > + typedef __true_type __type; > + }; > +#endif > + > + template<typename _Tp> > + struct __is_pointer<_Tp* const volatile> > + { > + enum { __value = 1 }; > + typedef __true_type __type; > + }; > + > // > // An arithmetic type is an integer type or a floating point type > // > diff --git a/libstdc++-v3/include/std/type_traits b/libstdc++-v3/include/std/type_traits > index 30b0778e58a..d53911b2fa0 100644 > --- a/libstdc++-v3/include/std/type_traits > +++ b/libstdc++-v3/include/std/type_traits > @@ -542,19 +542,33 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION > : public true_type { }; > #endif > > - template<typename> > - struct __is_pointer_helper > + /// is_pointer > +#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_pointer) > + template<typename _Tp> > + struct is_pointer > + : public __bool_constant<__is_pointer(_Tp)> > + { }; > +#else > + template<typename _Tp> > + struct is_pointer > : public false_type { }; > > template<typename _Tp> > - struct __is_pointer_helper<_Tp*> > + struct is_pointer<_Tp*> > : public true_type { }; > > - /// is_pointer > template<typename _Tp> > - struct is_pointer > - : public __is_pointer_helper<__remove_cv_t<_Tp>>::type > - { }; > + struct is_pointer<_Tp* const> > + : public true_type { }; > + > + template<typename _Tp> > + struct is_pointer<_Tp* volatile> > + : public true_type { }; > + > + template<typename _Tp> > + struct is_pointer<_Tp* const volatile> > + : public true_type { }; > +#endif > > /// is_lvalue_reference > template<typename> > @@ -3252,8 +3266,22 @@ template <typename _Tp, size_t _Num> > inline constexpr bool is_array_v<_Tp[_Num]> = true; > #endif > > +#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_pointer) > +template <typename _Tp> > + inline constexpr bool is_pointer_v = __is_pointer(_Tp); > +#else > template <typename _Tp> > - inline constexpr bool is_pointer_v = is_pointer<_Tp>::value; > + inline constexpr bool is_pointer_v = false; > +template <typename _Tp> > + inline constexpr bool is_pointer_v<_Tp*> = true; > +template <typename _Tp> > + inline constexpr bool is_pointer_v<_Tp* const> = true; > +template <typename _Tp> > + inline constexpr bool is_pointer_v<_Tp* volatile> = true; > +template <typename _Tp> > + inline constexpr bool is_pointer_v<_Tp* const volatile> = true; Is this fallback implementation faster than the current implementation? LGTM if so. > +#endif > + > template <typename _Tp> > inline constexpr bool is_lvalue_reference_v = false; > template <typename _Tp> > -- > 2.43.0 > >
On Sat, 23 Dec 2023 at 22:07, Ken Matsui <kmatsui@gcc.gnu.org> wrote: > > This patch optimizes the compilation performance of std::is_pointer > by dispatching to the new __is_pointer built-in trait. > > libstdc++-v3/ChangeLog: > > * include/bits/cpp_type_traits.h (__is_pointer): Use > __is_pointer built-in trait. Optimize its implementation. > * include/std/type_traits (is_pointer): Likewise. > (is_pointer_v): Likewise. > > Co-authored-by: Jonathan Wakely <jwakely@redhat.com> > Signed-off-by: Ken Matsui <kmatsui@gcc.gnu.org> > --- > libstdc++-v3/include/bits/cpp_type_traits.h | 29 ++++++++++++++ > libstdc++-v3/include/std/type_traits | 44 +++++++++++++++++---- > 2 files changed, 65 insertions(+), 8 deletions(-) > > diff --git a/libstdc++-v3/include/bits/cpp_type_traits.h b/libstdc++-v3/include/bits/cpp_type_traits.h > index 4312f32a4e0..c348df97f72 100644 > --- a/libstdc++-v3/include/bits/cpp_type_traits.h > +++ b/libstdc++-v3/include/bits/cpp_type_traits.h > @@ -363,6 +363,13 @@ __INT_N(__GLIBCXX_TYPE_INT_N_3) > // > // Pointer types > // > +#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_pointer) > + template<typename _Tp, bool _IsPtr = __is_pointer(_Tp)> > + struct __is_pointer : __truth_type<_IsPtr> > + { > + enum { __value = _IsPtr }; > + }; > +#else > template<typename _Tp> > struct __is_pointer > { > @@ -377,6 +384,28 @@ __INT_N(__GLIBCXX_TYPE_INT_N_3) > typedef __true_type __type; > }; > > + template<typename _Tp> > + struct __is_pointer<_Tp* const> > + { > + enum { __value = 1 }; > + typedef __true_type __type; > + }; > + > + template<typename _Tp> > + struct __is_pointer<_Tp* volatile> > + { > + enum { __value = 1 }; > + typedef __true_type __type; > + }; > +#endif > + > + template<typename _Tp> > + struct __is_pointer<_Tp* const volatile> > + { > + enum { __value = 1 }; > + typedef __true_type __type; > + }; Why is this partial specialization outside the #else group? > + > // > // An arithmetic type is an integer type or a floating point type > // > diff --git a/libstdc++-v3/include/std/type_traits b/libstdc++-v3/include/std/type_traits > index 30b0778e58a..d53911b2fa0 100644 > --- a/libstdc++-v3/include/std/type_traits > +++ b/libstdc++-v3/include/std/type_traits > @@ -542,19 +542,33 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION > : public true_type { }; > #endif > > - template<typename> > - struct __is_pointer_helper > + /// is_pointer > +#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_pointer) > + template<typename _Tp> > + struct is_pointer > + : public __bool_constant<__is_pointer(_Tp)> > + { }; > +#else > + template<typename _Tp> > + struct is_pointer > : public false_type { }; > > template<typename _Tp> > - struct __is_pointer_helper<_Tp*> > + struct is_pointer<_Tp*> > : public true_type { }; > > - /// is_pointer > template<typename _Tp> > - struct is_pointer > - : public __is_pointer_helper<__remove_cv_t<_Tp>>::type > - { }; > + struct is_pointer<_Tp* const> > + : public true_type { }; > + > + template<typename _Tp> > + struct is_pointer<_Tp* volatile> > + : public true_type { }; > + > + template<typename _Tp> > + struct is_pointer<_Tp* const volatile> > + : public true_type { }; > +#endif > > /// is_lvalue_reference > template<typename> > @@ -3252,8 +3266,22 @@ template <typename _Tp, size_t _Num> > inline constexpr bool is_array_v<_Tp[_Num]> = true; > #endif > > +#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_pointer) > +template <typename _Tp> > + inline constexpr bool is_pointer_v = __is_pointer(_Tp); > +#else > template <typename _Tp> > - inline constexpr bool is_pointer_v = is_pointer<_Tp>::value; > + inline constexpr bool is_pointer_v = false; > +template <typename _Tp> > + inline constexpr bool is_pointer_v<_Tp*> = true; > +template <typename _Tp> > + inline constexpr bool is_pointer_v<_Tp* const> = true; > +template <typename _Tp> > + inline constexpr bool is_pointer_v<_Tp* volatile> = true; > +template <typename _Tp> > + inline constexpr bool is_pointer_v<_Tp* const volatile> = true; > +#endif > + > template <typename _Tp> > inline constexpr bool is_lvalue_reference_v = false; > template <typename _Tp> > -- > 2.43.0 >
On Thu, 4 Jan 2024, Patrick Palka wrote: > On Sat, 23 Dec 2023, Ken Matsui wrote: > > > This patch optimizes the compilation performance of std::is_pointer > > by dispatching to the new __is_pointer built-in trait. > > > > libstdc++-v3/ChangeLog: > > > > * include/bits/cpp_type_traits.h (__is_pointer): Use > > __is_pointer built-in trait. Optimize its implementation. > > * include/std/type_traits (is_pointer): Likewise. > > (is_pointer_v): Likewise. > > > > Co-authored-by: Jonathan Wakely <jwakely@redhat.com> > > Signed-off-by: Ken Matsui <kmatsui@gcc.gnu.org> > > --- > > libstdc++-v3/include/bits/cpp_type_traits.h | 29 ++++++++++++++ > > libstdc++-v3/include/std/type_traits | 44 +++++++++++++++++---- > > 2 files changed, 65 insertions(+), 8 deletions(-) > > > > diff --git a/libstdc++-v3/include/bits/cpp_type_traits.h b/libstdc++-v3/include/bits/cpp_type_traits.h > > index 4312f32a4e0..c348df97f72 100644 > > --- a/libstdc++-v3/include/bits/cpp_type_traits.h > > +++ b/libstdc++-v3/include/bits/cpp_type_traits.h > > @@ -363,6 +363,13 @@ __INT_N(__GLIBCXX_TYPE_INT_N_3) > > // > > // Pointer types > > // > > +#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_pointer) > > + template<typename _Tp, bool _IsPtr = __is_pointer(_Tp)> > > + struct __is_pointer : __truth_type<_IsPtr> > > + { > > + enum { __value = _IsPtr }; > > + }; > > +#else > > template<typename _Tp> > > struct __is_pointer > > { > > @@ -377,6 +384,28 @@ __INT_N(__GLIBCXX_TYPE_INT_N_3) > > typedef __true_type __type; > > }; > > > > + template<typename _Tp> > > + struct __is_pointer<_Tp* const> > > + { > > + enum { __value = 1 }; > > + typedef __true_type __type; > > + }; > > + > > + template<typename _Tp> > > + struct __is_pointer<_Tp* volatile> > > + { > > + enum { __value = 1 }; > > + typedef __true_type __type; > > + }; > > +#endif > > + > > + template<typename _Tp> > > + struct __is_pointer<_Tp* const volatile> > > + { > > + enum { __value = 1 }; > > + typedef __true_type __type; > > + }; > > + > > // > > // An arithmetic type is an integer type or a floating point type > > // > > diff --git a/libstdc++-v3/include/std/type_traits b/libstdc++-v3/include/std/type_traits > > index 30b0778e58a..d53911b2fa0 100644 > > --- a/libstdc++-v3/include/std/type_traits > > +++ b/libstdc++-v3/include/std/type_traits > > @@ -542,19 +542,33 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION > > : public true_type { }; > > #endif > > > > - template<typename> > > - struct __is_pointer_helper > > + /// is_pointer > > +#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_pointer) > > + template<typename _Tp> > > + struct is_pointer > > + : public __bool_constant<__is_pointer(_Tp)> > > + { }; > > +#else > > + template<typename _Tp> > > + struct is_pointer > > : public false_type { }; > > > > template<typename _Tp> > > - struct __is_pointer_helper<_Tp*> > > + struct is_pointer<_Tp*> > > : public true_type { }; > > > > - /// is_pointer > > template<typename _Tp> > > - struct is_pointer > > - : public __is_pointer_helper<__remove_cv_t<_Tp>>::type > > - { }; > > + struct is_pointer<_Tp* const> > > + : public true_type { }; > > + > > + template<typename _Tp> > > + struct is_pointer<_Tp* volatile> > > + : public true_type { }; > > + > > + template<typename _Tp> > > + struct is_pointer<_Tp* const volatile> > > + : public true_type { }; > > +#endif > > > > /// is_lvalue_reference > > template<typename> > > @@ -3252,8 +3266,22 @@ template <typename _Tp, size_t _Num> > > inline constexpr bool is_array_v<_Tp[_Num]> = true; > > #endif > > > > +#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_pointer) > > +template <typename _Tp> > > + inline constexpr bool is_pointer_v = __is_pointer(_Tp); > > +#else > > template <typename _Tp> > > - inline constexpr bool is_pointer_v = is_pointer<_Tp>::value; > > + inline constexpr bool is_pointer_v = false; > > +template <typename _Tp> > > + inline constexpr bool is_pointer_v<_Tp*> = true; > > +template <typename _Tp> > > + inline constexpr bool is_pointer_v<_Tp* const> = true; > > +template <typename _Tp> > > + inline constexpr bool is_pointer_v<_Tp* volatile> = true; > > +template <typename _Tp> > > + inline constexpr bool is_pointer_v<_Tp* const volatile> = true; > > Is this fallback implementation faster than the current implementation? > LGTM if so. By the way, a related optimization might be to optimize __remove_cv_t via the built-in (related since the current fallback implementation is in terms of __remove_cv_t). This should be safe since the alias template isn't used in any function signature, so it's never mangled. > > > +#endif > > + > > template <typename _Tp> > > inline constexpr bool is_lvalue_reference_v = false; > > template <typename _Tp> > > -- > > 2.43.0 > > > > >
On Thu, Jan 4, 2024 at 2:16 PM Patrick Palka <ppalka@redhat.com> wrote: > > On Thu, 4 Jan 2024, Patrick Palka wrote: > > > On Sat, 23 Dec 2023, Ken Matsui wrote: > > > > > This patch optimizes the compilation performance of std::is_pointer > > > by dispatching to the new __is_pointer built-in trait. > > > > > > libstdc++-v3/ChangeLog: > > > > > > * include/bits/cpp_type_traits.h (__is_pointer): Use > > > __is_pointer built-in trait. Optimize its implementation. > > > * include/std/type_traits (is_pointer): Likewise. > > > (is_pointer_v): Likewise. > > > > > > Co-authored-by: Jonathan Wakely <jwakely@redhat.com> > > > Signed-off-by: Ken Matsui <kmatsui@gcc.gnu.org> > > > --- > > > libstdc++-v3/include/bits/cpp_type_traits.h | 29 ++++++++++++++ > > > libstdc++-v3/include/std/type_traits | 44 +++++++++++++++++---- > > > 2 files changed, 65 insertions(+), 8 deletions(-) > > > > > > diff --git a/libstdc++-v3/include/bits/cpp_type_traits.h b/libstdc++-v3/include/bits/cpp_type_traits.h > > > index 4312f32a4e0..c348df97f72 100644 > > > --- a/libstdc++-v3/include/bits/cpp_type_traits.h > > > +++ b/libstdc++-v3/include/bits/cpp_type_traits.h > > > @@ -363,6 +363,13 @@ __INT_N(__GLIBCXX_TYPE_INT_N_3) > > > // > > > // Pointer types > > > // > > > +#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_pointer) > > > + template<typename _Tp, bool _IsPtr = __is_pointer(_Tp)> > > > + struct __is_pointer : __truth_type<_IsPtr> > > > + { > > > + enum { __value = _IsPtr }; > > > + }; > > > +#else > > > template<typename _Tp> > > > struct __is_pointer > > > { > > > @@ -377,6 +384,28 @@ __INT_N(__GLIBCXX_TYPE_INT_N_3) > > > typedef __true_type __type; > > > }; > > > > > > + template<typename _Tp> > > > + struct __is_pointer<_Tp* const> > > > + { > > > + enum { __value = 1 }; > > > + typedef __true_type __type; > > > + }; > > > + > > > + template<typename _Tp> > > > + struct __is_pointer<_Tp* volatile> > > > + { > > > + enum { __value = 1 }; > > > + typedef __true_type __type; > > > + }; > > > +#endif > > > + > > > + template<typename _Tp> > > > + struct __is_pointer<_Tp* const volatile> > > > + { > > > + enum { __value = 1 }; > > > + typedef __true_type __type; > > > + }; > > > + > > > // > > > // An arithmetic type is an integer type or a floating point type > > > // > > > diff --git a/libstdc++-v3/include/std/type_traits b/libstdc++-v3/include/std/type_traits > > > index 30b0778e58a..d53911b2fa0 100644 > > > --- a/libstdc++-v3/include/std/type_traits > > > +++ b/libstdc++-v3/include/std/type_traits > > > @@ -542,19 +542,33 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION > > > : public true_type { }; > > > #endif > > > > > > - template<typename> > > > - struct __is_pointer_helper > > > + /// is_pointer > > > +#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_pointer) > > > + template<typename _Tp> > > > + struct is_pointer > > > + : public __bool_constant<__is_pointer(_Tp)> > > > + { }; > > > +#else > > > + template<typename _Tp> > > > + struct is_pointer > > > : public false_type { }; > > > > > > template<typename _Tp> > > > - struct __is_pointer_helper<_Tp*> > > > + struct is_pointer<_Tp*> > > > : public true_type { }; > > > > > > - /// is_pointer > > > template<typename _Tp> > > > - struct is_pointer > > > - : public __is_pointer_helper<__remove_cv_t<_Tp>>::type > > > - { }; > > > + struct is_pointer<_Tp* const> > > > + : public true_type { }; > > > + > > > + template<typename _Tp> > > > + struct is_pointer<_Tp* volatile> > > > + : public true_type { }; > > > + > > > + template<typename _Tp> > > > + struct is_pointer<_Tp* const volatile> > > > + : public true_type { }; > > > +#endif > > > > > > /// is_lvalue_reference > > > template<typename> > > > @@ -3252,8 +3266,22 @@ template <typename _Tp, size_t _Num> > > > inline constexpr bool is_array_v<_Tp[_Num]> = true; > > > #endif > > > > > > +#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_pointer) > > > +template <typename _Tp> > > > + inline constexpr bool is_pointer_v = __is_pointer(_Tp); > > > +#else > > > template <typename _Tp> > > > - inline constexpr bool is_pointer_v = is_pointer<_Tp>::value; > > > + inline constexpr bool is_pointer_v = false; > > > +template <typename _Tp> > > > + inline constexpr bool is_pointer_v<_Tp*> = true; > > > +template <typename _Tp> > > > + inline constexpr bool is_pointer_v<_Tp* const> = true; > > > +template <typename _Tp> > > > + inline constexpr bool is_pointer_v<_Tp* volatile> = true; > > > +template <typename _Tp> > > > + inline constexpr bool is_pointer_v<_Tp* const volatile> = true; > > > > Is this fallback implementation faster than the current implementation? > > LGTM if so. > Yes. Here are the benchmarks: 1 is current impl vs. built-in, and 2 is new impl vs. built-in. There is no explicit benchmark that compares the current impl and the new impl, but I think this shows the new impl is faster. 1. https://gcc.gnu.org/pipermail/gcc-patches/2023-July/624227.html Time: -62.1344% Peak Memory Usage: -52.4281% Total Memory Usage: -53.5889% 2. https://gcc.gnu.org/pipermail/gcc-patches/2023-July/624326.html Time: -2.79488% Peak Memory Usage: -2.39379% Total Memory Usage: -3.39559% > By the way, a related optimization might be to optimize __remove_cv_t > via the built-in (related since the current fallback implementation is > in terms of __remove_cv_t). This should be safe since the alias > template isn't used in any function signature, so it's never mangled. > Do we want to try this implementation as well? I think in this is_pointer case, the explicit specialization way is enough, but I am happy to hear your thoughts. > > > > > +#endif > > > + > > > template <typename _Tp> > > > inline constexpr bool is_lvalue_reference_v = false; > > > template <typename _Tp> > > > -- > > > 2.43.0 > > > > > > > > >
On Thu, Jan 4, 2024 at 2:13 PM Jonathan Wakely <jwakely@redhat.com> wrote: > > On Sat, 23 Dec 2023 at 22:07, Ken Matsui <kmatsui@gcc.gnu.org> wrote: > > > > This patch optimizes the compilation performance of std::is_pointer > > by dispatching to the new __is_pointer built-in trait. > > > > libstdc++-v3/ChangeLog: > > > > * include/bits/cpp_type_traits.h (__is_pointer): Use > > __is_pointer built-in trait. Optimize its implementation. > > * include/std/type_traits (is_pointer): Likewise. > > (is_pointer_v): Likewise. > > > > Co-authored-by: Jonathan Wakely <jwakely@redhat.com> > > Signed-off-by: Ken Matsui <kmatsui@gcc.gnu.org> > > --- > > libstdc++-v3/include/bits/cpp_type_traits.h | 29 ++++++++++++++ > > libstdc++-v3/include/std/type_traits | 44 +++++++++++++++++---- > > 2 files changed, 65 insertions(+), 8 deletions(-) > > > > diff --git a/libstdc++-v3/include/bits/cpp_type_traits.h b/libstdc++-v3/include/bits/cpp_type_traits.h > > index 4312f32a4e0..c348df97f72 100644 > > --- a/libstdc++-v3/include/bits/cpp_type_traits.h > > +++ b/libstdc++-v3/include/bits/cpp_type_traits.h > > @@ -363,6 +363,13 @@ __INT_N(__GLIBCXX_TYPE_INT_N_3) > > // > > // Pointer types > > // > > +#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_pointer) > > + template<typename _Tp, bool _IsPtr = __is_pointer(_Tp)> > > + struct __is_pointer : __truth_type<_IsPtr> > > + { > > + enum { __value = _IsPtr }; > > + }; > > +#else > > template<typename _Tp> > > struct __is_pointer > > { > > @@ -377,6 +384,28 @@ __INT_N(__GLIBCXX_TYPE_INT_N_3) > > typedef __true_type __type; > > }; > > > > + template<typename _Tp> > > + struct __is_pointer<_Tp* const> > > + { > > + enum { __value = 1 }; > > + typedef __true_type __type; > > + }; > > + > > + template<typename _Tp> > > + struct __is_pointer<_Tp* volatile> > > + { > > + enum { __value = 1 }; > > + typedef __true_type __type; > > + }; > > +#endif > > + > > + template<typename _Tp> > > + struct __is_pointer<_Tp* const volatile> > > + { > > + enum { __value = 1 }; > > + typedef __true_type __type; > > + }; > > Why is this partial specialization outside the #else group? > This is totally my fault. Thank you for pointing this out! > > > + > > // > > // An arithmetic type is an integer type or a floating point type > > // > > diff --git a/libstdc++-v3/include/std/type_traits b/libstdc++-v3/include/std/type_traits > > index 30b0778e58a..d53911b2fa0 100644 > > --- a/libstdc++-v3/include/std/type_traits > > +++ b/libstdc++-v3/include/std/type_traits > > @@ -542,19 +542,33 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION > > : public true_type { }; > > #endif > > > > - template<typename> > > - struct __is_pointer_helper > > + /// is_pointer > > +#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_pointer) > > + template<typename _Tp> > > + struct is_pointer > > + : public __bool_constant<__is_pointer(_Tp)> > > + { }; > > +#else > > + template<typename _Tp> > > + struct is_pointer > > : public false_type { }; > > > > template<typename _Tp> > > - struct __is_pointer_helper<_Tp*> > > + struct is_pointer<_Tp*> > > : public true_type { }; > > > > - /// is_pointer > > template<typename _Tp> > > - struct is_pointer > > - : public __is_pointer_helper<__remove_cv_t<_Tp>>::type > > - { }; > > + struct is_pointer<_Tp* const> > > + : public true_type { }; > > + > > + template<typename _Tp> > > + struct is_pointer<_Tp* volatile> > > + : public true_type { }; > > + > > + template<typename _Tp> > > + struct is_pointer<_Tp* const volatile> > > + : public true_type { }; > > +#endif > > > > /// is_lvalue_reference > > template<typename> > > @@ -3252,8 +3266,22 @@ template <typename _Tp, size_t _Num> > > inline constexpr bool is_array_v<_Tp[_Num]> = true; > > #endif > > > > +#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_pointer) > > +template <typename _Tp> > > + inline constexpr bool is_pointer_v = __is_pointer(_Tp); > > +#else > > template <typename _Tp> > > - inline constexpr bool is_pointer_v = is_pointer<_Tp>::value; > > + inline constexpr bool is_pointer_v = false; > > +template <typename _Tp> > > + inline constexpr bool is_pointer_v<_Tp*> = true; > > +template <typename _Tp> > > + inline constexpr bool is_pointer_v<_Tp* const> = true; > > +template <typename _Tp> > > + inline constexpr bool is_pointer_v<_Tp* volatile> = true; > > +template <typename _Tp> > > + inline constexpr bool is_pointer_v<_Tp* const volatile> = true; > > +#endif > > + > > template <typename _Tp> > > inline constexpr bool is_lvalue_reference_v = false; > > template <typename _Tp> > > -- > > 2.43.0 > > >
diff --git a/libstdc++-v3/include/bits/cpp_type_traits.h b/libstdc++-v3/include/bits/cpp_type_traits.h index 4312f32a4e0..c348df97f72 100644 --- a/libstdc++-v3/include/bits/cpp_type_traits.h +++ b/libstdc++-v3/include/bits/cpp_type_traits.h @@ -363,6 +363,13 @@ __INT_N(__GLIBCXX_TYPE_INT_N_3) // // Pointer types // +#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_pointer) + template<typename _Tp, bool _IsPtr = __is_pointer(_Tp)> + struct __is_pointer : __truth_type<_IsPtr> + { + enum { __value = _IsPtr }; + }; +#else template<typename _Tp> struct __is_pointer { @@ -377,6 +384,28 @@ __INT_N(__GLIBCXX_TYPE_INT_N_3) typedef __true_type __type; }; + template<typename _Tp> + struct __is_pointer<_Tp* const> + { + enum { __value = 1 }; + typedef __true_type __type; + }; + + template<typename _Tp> + struct __is_pointer<_Tp* volatile> + { + enum { __value = 1 }; + typedef __true_type __type; + }; +#endif + + template<typename _Tp> + struct __is_pointer<_Tp* const volatile> + { + enum { __value = 1 }; + typedef __true_type __type; + }; + // // An arithmetic type is an integer type or a floating point type // diff --git a/libstdc++-v3/include/std/type_traits b/libstdc++-v3/include/std/type_traits index 30b0778e58a..d53911b2fa0 100644 --- a/libstdc++-v3/include/std/type_traits +++ b/libstdc++-v3/include/std/type_traits @@ -542,19 +542,33 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION : public true_type { }; #endif - template<typename> - struct __is_pointer_helper + /// is_pointer +#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_pointer) + template<typename _Tp> + struct is_pointer + : public __bool_constant<__is_pointer(_Tp)> + { }; +#else + template<typename _Tp> + struct is_pointer : public false_type { }; template<typename _Tp> - struct __is_pointer_helper<_Tp*> + struct is_pointer<_Tp*> : public true_type { }; - /// is_pointer template<typename _Tp> - struct is_pointer - : public __is_pointer_helper<__remove_cv_t<_Tp>>::type - { }; + struct is_pointer<_Tp* const> + : public true_type { }; + + template<typename _Tp> + struct is_pointer<_Tp* volatile> + : public true_type { }; + + template<typename _Tp> + struct is_pointer<_Tp* const volatile> + : public true_type { }; +#endif /// is_lvalue_reference template<typename> @@ -3252,8 +3266,22 @@ template <typename _Tp, size_t _Num> inline constexpr bool is_array_v<_Tp[_Num]> = true; #endif +#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_pointer) +template <typename _Tp> + inline constexpr bool is_pointer_v = __is_pointer(_Tp); +#else template <typename _Tp> - inline constexpr bool is_pointer_v = is_pointer<_Tp>::value; + inline constexpr bool is_pointer_v = false; +template <typename _Tp> + inline constexpr bool is_pointer_v<_Tp*> = true; +template <typename _Tp> + inline constexpr bool is_pointer_v<_Tp* const> = true; +template <typename _Tp> + inline constexpr bool is_pointer_v<_Tp* volatile> = true; +template <typename _Tp> + inline constexpr bool is_pointer_v<_Tp* const volatile> = true; +#endif + template <typename _Tp> inline constexpr bool is_lvalue_reference_v = false; template <typename _Tp>
This patch optimizes the compilation performance of std::is_pointer by dispatching to the new __is_pointer built-in trait. libstdc++-v3/ChangeLog: * include/bits/cpp_type_traits.h (__is_pointer): Use __is_pointer built-in trait. Optimize its implementation. * include/std/type_traits (is_pointer): Likewise. (is_pointer_v): Likewise. Co-authored-by: Jonathan Wakely <jwakely@redhat.com> Signed-off-by: Ken Matsui <kmatsui@gcc.gnu.org> --- libstdc++-v3/include/bits/cpp_type_traits.h | 29 ++++++++++++++ libstdc++-v3/include/std/type_traits | 44 +++++++++++++++++---- 2 files changed, 65 insertions(+), 8 deletions(-)