https://gcc.gnu.org/g:13a07c1420b35ac7649f7d8a776b553ec5c26269
commit r15-1290-g13a07c1420b35ac7649f7d8a776b553ec5c26269
Author: Ken Matsui <kmat...@gcc.gnu.org>
Date: Wed Feb 14 23:22:57 2024 -0800
libstdc++: Optimize std::add_lvalue_reference compilation performance
This patch optimizes the compilation performance of
std::add_lvalue_reference by dispatching to the new
__add_lvalue_reference built-in trait.
libstdc++-v3/ChangeLog:
* include/std/type_traits (__add_lval_ref_t): Use
__add_lvalue_reference built-in trait.
Signed-off-by: Ken Matsui <kmat...@gcc.gnu.org>
Reviewed-by: Patrick Palka <ppa...@redhat.com>
Reviewed-by: Jonathan Wakely <jwak...@redhat.com>
Diff:
---
libstdc++-v3/include/std/type_traits | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/libstdc++-v3/include/std/type_traits
b/libstdc++-v3/include/std/type_traits
index 0ef112926575..79983ea980a1 100644
--- a/libstdc++-v3/include/std/type_traits
+++ b/libstdc++-v3/include/std/type_traits
@@ -1157,6 +1157,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
};
/// @cond undocumented
+#if _GLIBCXX_USE_BUILTIN_TRAIT(__add_lvalue_reference)
+ template<typename _Tp>
+ using __add_lval_ref_t = __add_lvalue_reference(_Tp);
+#else
template<typename _Tp, typename = void>
struct __add_lvalue_reference_helper
{ using type = _Tp; };
@@ -1167,6 +1171,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename _Tp>
using __add_lval_ref_t = typename __add_lvalue_reference_helper<_Tp>::type;
+#endif
/// @endcond
/// is_copy_constructible
