[v13,22/26] libstdc++: Optimize std::rank compilation performance

Message ID 20240221093616.4001742-22-kmatsui@gcc.gnu.org
State Superseded
Headers
Series [v13,01/26] c++: Implement __is_const built-in trait |

Checks

Context Check Description
linaro-tcwg-bot/tcwg_gcc_build--master-aarch64 success Testing passed
linaro-tcwg-bot/tcwg_gcc_check--master-aarch64 success Testing passed
linaro-tcwg-bot/tcwg_gcc_build--master-arm success Testing passed
linaro-tcwg-bot/tcwg_gcc_check--master-arm success Testing passed

Commit Message

Ken Matsui Feb. 21, 2024, 9:36 a.m. UTC
  This patch optimizes the compilation performance of std::rank
by dispatching to the new __rank built-in trait.

libstdc++-v3/ChangeLog:

	* include/std/type_traits (rank): Use __rank built-in trait.
	(rank_v): Likewise.

Signed-off-by: Ken Matsui <kmatsui@gcc.gnu.org>
---
 libstdc++-v3/include/std/type_traits | 11 +++++++++++
 1 file changed, 11 insertions(+)
  

Patch

diff --git a/libstdc++-v3/include/std/type_traits b/libstdc++-v3/include/std/type_traits
index 2f4c8dd3b21..1577042a5b8 100644
--- a/libstdc++-v3/include/std/type_traits
+++ b/libstdc++-v3/include/std/type_traits
@@ -1473,6 +1473,11 @@  _GLIBCXX_BEGIN_NAMESPACE_VERSION
     };
 
   /// rank
+#if _GLIBCXX_USE_BUILTIN_TRAIT(__rank)
+  template<typename _Tp>
+    struct rank
+    : public integral_constant<std::size_t, __rank(_Tp)> { };
+#else
   template<typename>
     struct rank
     : public integral_constant<std::size_t, 0> { };
@@ -1484,6 +1489,7 @@  _GLIBCXX_BEGIN_NAMESPACE_VERSION
   template<typename _Tp>
     struct rank<_Tp[]>
     : public integral_constant<std::size_t, 1 + rank<_Tp>::value> { };
+#endif
 
   /// extent
   template<typename, unsigned _Uint = 0>
@@ -3579,12 +3585,17 @@  template <typename _Tp>
 template <typename _Tp>
   inline constexpr size_t alignment_of_v = alignment_of<_Tp>::value;
 
+#if _GLIBCXX_USE_BUILTIN_TRAIT(__rank)
+template <typename _Tp>
+  inline constexpr size_t rank_v = __rank(_Tp);
+#else
 template <typename _Tp>
   inline constexpr size_t rank_v = 0;
 template <typename _Tp, size_t _Size>
   inline constexpr size_t rank_v<_Tp[_Size]> = 1 + rank_v<_Tp>;
 template <typename _Tp>
   inline constexpr size_t rank_v<_Tp[]> = 1 + rank_v<_Tp>;
+#endif
 
 template <typename _Tp, unsigned _Idx = 0>
   inline constexpr size_t extent_v = 0;