[v10,2/5] libstdc++: Use new built-in trait __is_reference for std::is_reference

Message ID 20230713023731.15571-3-kmatsui@gcc.gnu.org
State Accepted
Headers
Series c++, libstdc++: Make std::is_object dispatch to new built-in traits |

Checks

Context Check Description
snail/gcc-patch-check success Github commit url

Commit Message

Ken Matsui July 13, 2023, 2:33 a.m. UTC
  This patch gets std::is_reference to dispatch to new built-in trait
__is_reference.

libstdc++-v3/ChangeLog:

	* include/std/type_traits (is_reference): Use __is_reference built-in
	trait.
	(is_reference_v): Likewise.

Signed-off-by: Ken Matsui <kmatsui@gcc.gnu.org>
---
 libstdc++-v3/include/std/type_traits | 14 ++++++++++++++
 1 file changed, 14 insertions(+)
  

Comments

Ken Matsui July 13, 2023, 2:56 a.m. UTC | #1
Hi,

Here is the benchmark result for is_reference:

https://github.com/ken-matsui/gcc-benches/blob/main/is_reference.md#wed-jul-12-074702-pm-pdt-2023

Time: -8.15593%
Peak Memory Usage: -4.48408%
Total Memory Usage: -8.03783%

Sincerely,
Ken Matsui

On Wed, Jul 12, 2023 at 7:39 PM Ken Matsui <kmatsui@gcc.gnu.org> wrote:
>
> This patch gets std::is_reference to dispatch to new built-in trait
> __is_reference.
>
> libstdc++-v3/ChangeLog:
>
>         * include/std/type_traits (is_reference): Use __is_reference built-in
>         trait.
>         (is_reference_v): Likewise.
>
> Signed-off-by: Ken Matsui <kmatsui@gcc.gnu.org>
> ---
>  libstdc++-v3/include/std/type_traits | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)
>
> diff --git a/libstdc++-v3/include/std/type_traits b/libstdc++-v3/include/std/type_traits
> index 0e7a9c9c7f3..2a14df7e5f9 100644
> --- a/libstdc++-v3/include/std/type_traits
> +++ b/libstdc++-v3/include/std/type_traits
> @@ -639,6 +639,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
>    // Composite type categories.
>
>    /// is_reference
> +#if __has_builtin(__is_reference)
> +  template<typename _Tp>
> +    struct is_reference
> +    : public __bool_constant<__is_reference(_Tp)>
> +    { };
> +#else
>    template<typename _Tp>
>      struct is_reference
>      : public false_type
> @@ -653,6 +659,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
>      struct is_reference<_Tp&&>
>      : public true_type
>      { };
> +#endif
>
>    /// is_arithmetic
>    template<typename _Tp>
> @@ -3192,12 +3199,19 @@ template <typename _Tp>
>    inline constexpr bool is_class_v = __is_class(_Tp);
>  template <typename _Tp>
>    inline constexpr bool is_function_v = is_function<_Tp>::value;
> +
> +#if __has_builtin(__is_reference)
> +template <typename _Tp>
> +  inline constexpr bool is_reference_v = __is_reference(_Tp);
> +#else
>  template <typename _Tp>
>    inline constexpr bool is_reference_v = false;
>  template <typename _Tp>
>    inline constexpr bool is_reference_v<_Tp&> = true;
>  template <typename _Tp>
>    inline constexpr bool is_reference_v<_Tp&&> = true;
> +#endif
> +
>  template <typename _Tp>
>    inline constexpr bool is_arithmetic_v = is_arithmetic<_Tp>::value;
>  template <typename _Tp>
> --
> 2.41.0
>
  
Ken Matsui Sept. 4, 2023, 3 p.m. UTC | #2
Ping for __is_reference built-in.

Sincerely,
Ken Matsui


On Wed, Jul 12, 2023 at 7:56 PM Ken Matsui <kmatsui@cs.washington.edu> wrote:
>
> Hi,
>
> Here is the benchmark result for is_reference:
>
> https://github.com/ken-matsui/gcc-benches/blob/main/is_reference.md#wed-jul-12-074702-pm-pdt-2023
>
> Time: -8.15593%
> Peak Memory Usage: -4.48408%
> Total Memory Usage: -8.03783%
>
> Sincerely,
> Ken Matsui
>
> On Wed, Jul 12, 2023 at 7:39 PM Ken Matsui <kmatsui@gcc.gnu.org> wrote:
> >
> > This patch gets std::is_reference to dispatch to new built-in trait
> > __is_reference.
> >
> > libstdc++-v3/ChangeLog:
> >
> >         * include/std/type_traits (is_reference): Use __is_reference built-in
> >         trait.
> >         (is_reference_v): Likewise.
> >
> > Signed-off-by: Ken Matsui <kmatsui@gcc.gnu.org>
> > ---
> >  libstdc++-v3/include/std/type_traits | 14 ++++++++++++++
> >  1 file changed, 14 insertions(+)
> >
> > diff --git a/libstdc++-v3/include/std/type_traits b/libstdc++-v3/include/std/type_traits
> > index 0e7a9c9c7f3..2a14df7e5f9 100644
> > --- a/libstdc++-v3/include/std/type_traits
> > +++ b/libstdc++-v3/include/std/type_traits
> > @@ -639,6 +639,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> >    // Composite type categories.
> >
> >    /// is_reference
> > +#if __has_builtin(__is_reference)
> > +  template<typename _Tp>
> > +    struct is_reference
> > +    : public __bool_constant<__is_reference(_Tp)>
> > +    { };
> > +#else
> >    template<typename _Tp>
> >      struct is_reference
> >      : public false_type
> > @@ -653,6 +659,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> >      struct is_reference<_Tp&&>
> >      : public true_type
> >      { };
> > +#endif
> >
> >    /// is_arithmetic
> >    template<typename _Tp>
> > @@ -3192,12 +3199,19 @@ template <typename _Tp>
> >    inline constexpr bool is_class_v = __is_class(_Tp);
> >  template <typename _Tp>
> >    inline constexpr bool is_function_v = is_function<_Tp>::value;
> > +
> > +#if __has_builtin(__is_reference)
> > +template <typename _Tp>
> > +  inline constexpr bool is_reference_v = __is_reference(_Tp);
> > +#else
> >  template <typename _Tp>
> >    inline constexpr bool is_reference_v = false;
> >  template <typename _Tp>
> >    inline constexpr bool is_reference_v<_Tp&> = true;
> >  template <typename _Tp>
> >    inline constexpr bool is_reference_v<_Tp&&> = true;
> > +#endif
> > +
> >  template <typename _Tp>
> >    inline constexpr bool is_arithmetic_v = is_arithmetic<_Tp>::value;
> >  template <typename _Tp>
> > --
> > 2.41.0
> >
  

Patch

diff --git a/libstdc++-v3/include/std/type_traits b/libstdc++-v3/include/std/type_traits
index 0e7a9c9c7f3..2a14df7e5f9 100644
--- a/libstdc++-v3/include/std/type_traits
+++ b/libstdc++-v3/include/std/type_traits
@@ -639,6 +639,12 @@  _GLIBCXX_BEGIN_NAMESPACE_VERSION
   // Composite type categories.
 
   /// is_reference
+#if __has_builtin(__is_reference)
+  template<typename _Tp>
+    struct is_reference
+    : public __bool_constant<__is_reference(_Tp)>
+    { };
+#else
   template<typename _Tp>
     struct is_reference
     : public false_type
@@ -653,6 +659,7 @@  _GLIBCXX_BEGIN_NAMESPACE_VERSION
     struct is_reference<_Tp&&>
     : public true_type
     { };
+#endif
 
   /// is_arithmetic
   template<typename _Tp>
@@ -3192,12 +3199,19 @@  template <typename _Tp>
   inline constexpr bool is_class_v = __is_class(_Tp);
 template <typename _Tp>
   inline constexpr bool is_function_v = is_function<_Tp>::value;
+
+#if __has_builtin(__is_reference)
+template <typename _Tp>
+  inline constexpr bool is_reference_v = __is_reference(_Tp);
+#else
 template <typename _Tp>
   inline constexpr bool is_reference_v = false;
 template <typename _Tp>
   inline constexpr bool is_reference_v<_Tp&> = true;
 template <typename _Tp>
   inline constexpr bool is_reference_v<_Tp&&> = true;
+#endif
+
 template <typename _Tp>
   inline constexpr bool is_arithmetic_v = is_arithmetic<_Tp>::value;
 template <typename _Tp>