[PATCH v11 34/40] libstdc++: Optimize is_compound trait performance

Ken Matsui kmatsui@gcc.gnu.org
Thu Sep 14 06:43:13 GMT 2023


This patch optimizes the performance of the is_compound trait by dispatching
to the new __is_arithmetic built-in trait.

libstdc++-v3/ChangeLog:

	* include/std/type_traits (is_compound): Do not use __not_.
	(is_compound_v): Use is_fundamental_v instead.

Signed-off-by: Ken Matsui <kmatsui@gcc.gnu.org>
---
 libstdc++-v3/include/std/type_traits | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/libstdc++-v3/include/std/type_traits b/libstdc++-v3/include/std/type_traits
index 88171e1a672..48d630a1478 100644
--- a/libstdc++-v3/include/std/type_traits
+++ b/libstdc++-v3/include/std/type_traits
@@ -784,7 +784,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
   /// is_compound
   template<typename _Tp>
     struct is_compound
-    : public __not_<is_fundamental<_Tp>>::type { };
+    : public __bool_constant<!is_fundamental<_Tp>::value> { };
 
   /// is_member_pointer
 #if _GLIBCXX_USE_BUILTIN_TRAIT(__is_member_pointer)
@@ -3387,7 +3387,7 @@ template <typename _Tp>
 template <typename _Tp>
   inline constexpr bool is_scalar_v = is_scalar<_Tp>::value;
 template <typename _Tp>
-  inline constexpr bool is_compound_v = is_compound<_Tp>::value;
+  inline constexpr bool is_compound_v = !is_fundamental_v<_Tp>;
 
 #if _GLIBCXX_USE_BUILTIN_TRAIT(__is_member_pointer)
 template <typename _Tp>
-- 
2.42.0



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