diff mbox series

[6/7] libstdc++: Add always_inline to some one-liners in <bits/stl_algobase.h>

Message ID 20241015142630.2148792-6-jwakely@redhat.com
State New
Headers show
Series [1/7] libstdc++: Refactor std::uninitialized_{copy, fill, fill_n} algos [PR68350] | expand

Commit Message

Jonathan Wakely Oct. 15, 2024, 2:20 p.m. UTC 
Tested x86_64-linux.

-- >8 --

We implement std::copy, std::fill etc. as a series of calls to other
overloads which incrementally peel off layers of iterator wrappers. This
adds a high abstraction penalty for -O0 and potentially even -O1. Add
the always_inline attribute to several functions that are just a single
return statement (and maybe a static_assert, or some concept-checking
assertions which are disabled by default).

libstdc++-v3/ChangeLog:

	* include/bits/stl_algobase.h (__copy_move_a1, __copy_move_a)
	(__copy_move_backward_a1, __copy_move_backward_a, move_backward)
	(__fill_a1, __fill_a, fill, __fill_n_a, fill_n, __equal_aux):
	Add always_inline attribute to one-line forwarding functions.
---
 libstdc++-v3/include/bits/stl_algobase.h | 14 ++++++++++++++
 1 file changed, 14 insertions(+)
diff mbox series

Patch

diff --git a/libstdc++-v3/include/bits/stl_algobase.h b/libstdc++-v3/include/bits/stl_algobase.h
index d9d1d00b113..b2f5b96d46e 100644
--- a/libstdc++-v3/include/bits/stl_algobase.h
+++ b/libstdc++-v3/include/bits/stl_algobase.h
@@ -500,12 +500,14 @@  _GLIBCXX_END_NAMESPACE_CONTAINER
     __copy_move_a1(_II, _II, _GLIBCXX_STD_C::_Deque_iterator<_Tp, _Tp&, _Tp*>);
 
   template<bool _IsMove, typename _II, typename _OI>
+    __attribute__((__always_inline__))
     _GLIBCXX20_CONSTEXPR
     inline _OI
     __copy_move_a1(_II __first, _II __last, _OI __result)
     { return std::__copy_move_a2<_IsMove>(__first, __last, __result); }
 
   template<bool _IsMove, typename _II, typename _OI>
+    __attribute__((__always_inline__))
     _GLIBCXX20_CONSTEXPR
     inline _OI
     __copy_move_a(_II __first, _II __last, _OI __result)
@@ -757,6 +759,7 @@  _GLIBCXX_END_NAMESPACE_CONTAINER
 #undef _GLIBCXX_ADVANCE
 
   template<bool _IsMove, typename _BI1, typename _BI2>
+    __attribute__((__always_inline__))
     _GLIBCXX20_CONSTEXPR
     inline _BI2
     __copy_move_backward_a1(_BI1 __first, _BI1 __last, _BI2 __result)
@@ -785,6 +788,7 @@  _GLIBCXX_END_NAMESPACE_CONTAINER
 			    _GLIBCXX_STD_C::_Deque_iterator<_Tp, _Tp&, _Tp*>);
 
   template<bool _IsMove, typename _II, typename _OI>
+    __attribute__((__always_inline__))
     _GLIBCXX20_CONSTEXPR
     inline _OI
     __copy_move_backward_a(_II __first, _II __last, _OI __result)
@@ -840,6 +844,7 @@  _GLIBCXX_END_NAMESPACE_CONTAINER
    *  that the start of the output range may overlap [first,last).
   */
   template<typename _BI1, typename _BI2>
+    __attribute__((__always_inline__))
     _GLIBCXX20_CONSTEXPR
     inline _BI2
     copy_backward(_BI1 __first, _BI1 __last, _BI2 __result)
@@ -875,6 +880,7 @@  _GLIBCXX_END_NAMESPACE_CONTAINER
    *  that the start of the output range may overlap [first,last).
   */
   template<typename _BI1, typename _BI2>
+    __attribute__((__always_inline__))
     _GLIBCXX20_CONSTEXPR
     inline _BI2
     move_backward(_BI1 __first, _BI1 __last, _BI2 __result)
@@ -958,6 +964,7 @@  _GLIBCXX_END_NAMESPACE_CONTAINER
     }
 
   template<typename _Ite, typename _Cont, typename _Tp>
+    __attribute__((__always_inline__))
     _GLIBCXX20_CONSTEXPR
     inline void
     __fill_a1(::__gnu_cxx::__normal_iterator<_Ite, _Cont> __first,
@@ -977,6 +984,7 @@  _GLIBCXX_END_NAMESPACE_CONTAINER
 	    const bool&);
 
   template<typename _FIte, typename _Tp>
+    __attribute__((__always_inline__))
     _GLIBCXX20_CONSTEXPR
     inline void
     __fill_a(_FIte __first, _FIte __last, const _Tp& __value)
@@ -1002,6 +1010,7 @@  _GLIBCXX_END_NAMESPACE_CONTAINER
    *  to @c memset or @c wmemset.
   */
   template<typename _ForwardIterator, typename _Tp>
+    __attribute__((__always_inline__))
     _GLIBCXX20_CONSTEXPR
     inline void
     fill(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value)
@@ -1108,6 +1117,7 @@  _GLIBCXX_END_NAMESPACE_CONTAINER
 	       std::input_iterator_tag);
 
   template<typename _OutputIterator, typename _Size, typename _Tp>
+    __attribute__((__always_inline__))
     _GLIBCXX20_CONSTEXPR
     inline _OutputIterator
     __fill_n_a(_OutputIterator __first, _Size __n, const _Tp& __value,
@@ -1120,6 +1130,7 @@  _GLIBCXX_END_NAMESPACE_CONTAINER
     }
 
   template<typename _OutputIterator, typename _Size, typename _Tp>
+    __attribute__((__always_inline__))
     _GLIBCXX20_CONSTEXPR
     inline _OutputIterator
     __fill_n_a(_OutputIterator __first, _Size __n, const _Tp& __value,
@@ -1132,6 +1143,7 @@  _GLIBCXX_END_NAMESPACE_CONTAINER
     }
 
   template<typename _OutputIterator, typename _Size, typename _Tp>
+    __attribute__((__always_inline__))
     _GLIBCXX20_CONSTEXPR
     inline _OutputIterator
     __fill_n_a(_OutputIterator __first, _Size __n, const _Tp& __value,
@@ -1167,6 +1179,7 @@  _GLIBCXX_END_NAMESPACE_CONTAINER
   // DR 865. More algorithms that throw away information
   // DR 426. search_n(), fill_n(), and generate_n() with negative n
   template<typename _OI, typename _Size, typename _Tp>
+    __attribute__((__always_inline__))
     _GLIBCXX20_CONSTEXPR
     inline _OI
     fill_n(_OI __first, _Size __n, const _Tp& __value)
@@ -1246,6 +1259,7 @@  _GLIBCXX_END_NAMESPACE_CONTAINER
     }
 
   template<typename _II1, typename _II2>
+    __attribute__((__always_inline__))
     _GLIBCXX20_CONSTEXPR
     inline bool
     __equal_aux(_II1 __first1, _II1 __last1, _II2 __first2)