| Message ID | 20231016001227.2717180-31-kmatsui@gcc.gnu.org |
|---|---|
| State | New |
| Headers | show |
| Series | Optimize type traits performance | expand |
On Sun, 15 Oct 2023, Ken Matsui wrote: > This patch optimizes the performance of the is_pointer trait 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. > * include/std/type_traits (is_pointer): Likewise. Optimize its > implementation. > (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 | 8 ++++ > libstdc++-v3/include/std/type_traits | 44 +++++++++++++++++---- > 2 files changed, 44 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..cd5ce45951f 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 __has_builtin(__is_pointer) Why not _GLIBCXX_USE_BUILTIN_TRAIT? LGTM besides this. > + template<typename _Tp> > + struct __is_pointer : __truth_type<__is_pointer(_Tp)> > + { > + enum { __value = __is_pointer(_Tp) }; > + }; Nice :D > +#else > template<typename _Tp> > struct __is_pointer > { > @@ -376,6 +383,7 @@ __INT_N(__GLIBCXX_TYPE_INT_N_3) > enum { __value = 1 }; > typedef __true_type __type; > }; > +#endif > > // > // 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 9c56d15c0b7..3acd843f2f2 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> > @@ -3254,8 +3268,22 @@ 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> > -- > 2.42.0 > >
On Mon, Oct 16, 2023 at 9:36 AM Patrick Palka <ppalka@redhat.com> wrote: > > On Sun, 15 Oct 2023, Ken Matsui wrote: > > > This patch optimizes the performance of the is_pointer trait 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. > > * include/std/type_traits (is_pointer): Likewise. Optimize its > > implementation. > > (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 | 8 ++++ > > libstdc++-v3/include/std/type_traits | 44 +++++++++++++++++---- > > 2 files changed, 44 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..cd5ce45951f 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 __has_builtin(__is_pointer) > > Why not _GLIBCXX_USE_BUILTIN_TRAIT? LGTM besides this. > Oops, thank you for pointing this out :) > > + template<typename _Tp> > > + struct __is_pointer : __truth_type<__is_pointer(_Tp)> > > + { > > + enum { __value = __is_pointer(_Tp) }; > > + }; > > Nice :D > Yeees! But I thought this might be very confusing for someone who does not know the new built-in behavior. > > +#else > > template<typename _Tp> > > struct __is_pointer > > { > > @@ -376,6 +383,7 @@ __INT_N(__GLIBCXX_TYPE_INT_N_3) > > enum { __value = 1 }; > > typedef __true_type __type; > > }; > > +#endif > > > > // > > // 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 9c56d15c0b7..3acd843f2f2 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> > > @@ -3254,8 +3268,22 @@ 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> > > -- > > 2.42.0 > > > > >
diff --git a/libstdc++-v3/include/bits/cpp_type_traits.h b/libstdc++-v3/include/bits/cpp_type_traits.h index 4312f32a4e0..cd5ce45951f 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 __has_builtin(__is_pointer) + template<typename _Tp> + struct __is_pointer : __truth_type<__is_pointer(_Tp)> + { + enum { __value = __is_pointer(_Tp) }; + }; +#else template<typename _Tp> struct __is_pointer { @@ -376,6 +383,7 @@ __INT_N(__GLIBCXX_TYPE_INT_N_3) enum { __value = 1 }; typedef __true_type __type; }; +#endif // // 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 9c56d15c0b7..3acd843f2f2 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> @@ -3254,8 +3268,22 @@ 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 performance of the is_pointer trait 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. * include/std/type_traits (is_pointer): Likewise. Optimize its implementation. (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 | 8 ++++ libstdc++-v3/include/std/type_traits | 44 +++++++++++++++++---- 2 files changed, 44 insertions(+), 8 deletions(-)