[PATCH v16 12/26] libstdc++: Optimize std::remove_extent compilation performance

[Ken Matsui]

This patch optimizes the compilation performance of std::remove_extent
by dispatching to the new __builtin_remove_extent trait.

libstdc++-v3/ChangeLog:

        * include/std/type_traits (remove_extent): Use
        __builtin_remove_extent trait.

Signed-off-by: Ken Matsui <kmat...@gcc.gnu.org>
---
 libstdc++-v3/include/std/type_traits | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/libstdc++-v3/include/std/type_traits 
b/libstdc++-v3/include/std/type_traits
index 59d952194af..36136440fdd 100644
--- a/libstdc++-v3/include/std/type_traits
+++ b/libstdc++-v3/include/std/type_traits
@@ -2092,6 +2092,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
   // Array modifications.
 
   /// remove_extent
+#if _GLIBCXX_USE_BUILTIN_TRAIT(__builtin_remove_extent)
+  template<typename _Tp>
+    struct remove_extent
+    { using type = __builtin_remove_extent(_Tp); };
+#else
   template<typename _Tp>
     struct remove_extent
     { using type = _Tp; };
@@ -2103,6 +2108,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
   template<typename _Tp>
     struct remove_extent<_Tp[]>
     { using type = _Tp; };
+#endif
 
   /// remove_all_extents
   template<typename _Tp>
-- 
2.44.0