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| author | Ken Matsui <kmatsui@gcc.gnu.org> | 2023-06-10 21:01:39 -0700 |
|---|---|---|
| committer | Ken Matsui <kmatsui@gcc.gnu.org> | 2023-12-16 08:59:38 -0800 |
| commit | cdd4387c5b6aeace2e58318691a5880d29157db9 (patch) | |
| tree | f3a84f6c716fd097fe8ef1b9d66c4ca27e865f71 | |
| parent | e86cfcaef246331ee7956dd86c156d594768fe70 (diff) | |
| download | gcc-cdd4387c5b6aeace2e58318691a5880d29157db9.zip gcc-cdd4387c5b6aeace2e58318691a5880d29157db9.tar.gz gcc-cdd4387c5b6aeace2e58318691a5880d29157db9.tar.bz2 | |
libstdc++: Optimize std::is_function compilation performance
This patch optimizes the compilation performance of std::is_function
by dispatching to the new __is_function built-in trait.
libstdc++-v3/ChangeLog:
* include/std/type_traits (is_function): Use __is_function
built-in trait.
(is_function_v): Likewise. Optimize its implementation. Move
this under is_const_v as this depends on is_const_v.
Signed-off-by: Ken Matsui <kmatsui@gcc.gnu.org>
Reviewed-by: Jonathan Wakely <jwakely@redhat.com>
| -rw-r--r-- | libstdc++-v3/include/std/type_traits | 23 |
1 files changed, 21 insertions, 2 deletions
diff --git a/libstdc++-v3/include/std/type_traits b/libstdc++-v3/include/std/type_traits index db880d8..b6d0441 100644 --- a/libstdc++-v3/include/std/type_traits +++ b/libstdc++-v3/include/std/type_traits @@ -637,6 +637,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION { }; /// is_function +#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_function) + template<typename _Tp> + struct is_function + : public __bool_constant<__is_function(_Tp)> + { }; +#else template<typename _Tp> struct is_function : public __bool_constant<!is_const<const _Tp>::value> { }; @@ -648,6 +654,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION template<typename _Tp> struct is_function<_Tp&&> : public false_type { }; +#endif #ifdef __cpp_lib_is_null_pointer // C++ >= 11 /// is_null_pointer (LWG 2247). @@ -3255,8 +3262,7 @@ template <typename _Tp> inline constexpr bool is_union_v = __is_union(_Tp); 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; +// is_function_v is defined below, after is_const_v. #if _GLIBCXX_USE_BUILTIN_TRAIT(__is_reference) template <typename _Tp> @@ -3293,6 +3299,19 @@ template <typename _Tp> inline constexpr bool is_const_v = false; template <typename _Tp> inline constexpr bool is_const_v<const _Tp> = true; + +#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_function) +template <typename _Tp> + inline constexpr bool is_function_v = __is_function(_Tp); +#else +template <typename _Tp> + inline constexpr bool is_function_v = !is_const_v<const _Tp>; +template <typename _Tp> + inline constexpr bool is_function_v<_Tp&> = false; +template <typename _Tp> + inline constexpr bool is_function_v<_Tp&&> = false; +#endif + template <typename _Tp> inline constexpr bool is_volatile_v = false; template <typename _Tp> |