On Fri, 21 Aug 2026 at 20:23 +0800, Yuao Ma wrote:
On Thu, Aug 20, 2026 at 11:34 PM Jonathan Wakely <[email protected]> wrote:
On Thu, 20 Aug 2026 at 14:38, Yuao Ma <[email protected]> wrote:
>
> Hi!
>
> Based on previous discussions, we could remove the gnu++11 flag in the
> check performance script. And the rebind logic removed in c++20 is
> also adjusted.
This makes the pb_ds performance tests unable to run as C++98, because
that doesn't have std::allocator_traits. So if anybody wanted to
compare performance of those containers in C++98 and C++20 (or C++11),
maybe because they were adding move semantics to the pb_ds containers,
the performance tests would not work.
Although I really don't care about the pb_ds tests (because pb_ds is
unmaintained and should be moved to a separate repo), you could make
it work for all versions of C++ by using __gnu_cxx::__alloc_traits
instead of std::allocator_traits.
Thanks for the review! Indeed when I made the change in the patch I
did not think about the compatibility of c++98. Fixed in the new
patch.
>
> Tested with make check-performance, ok for trunk?
>
> Thanks,
> Yuao
From b243166201265b86491044b20bdba79116766ae6 Mon Sep 17 00:00:00 2001
From: Yuao Ma <[email protected]>
Date: Fri, 21 Aug 2026 20:21:13 +0800
Subject: [PATCH] libstdc++: remove the gnu++11 in check performance script
Nowadays gcc's default c++ version is gnu++20, maybe we should just use
this in performance check as well.
libstdc++-v3/ChangeLog:
* scripts/check_performance: Remove gnu++11 flag.
* testsuite/util/native_type/native_hash_map.hpp: Adjust rebind
usage.
* testsuite/util/native_type/native_hash_multimap.hpp: Ditto.
* testsuite/util/native_type/native_hash_set.hpp: Ditto.
* testsuite/util/native_type/native_map.hpp: Ditto.
* testsuite/util/native_type/native_multimap.hpp: Ditto.
* testsuite/util/native_type/native_set.hpp: Ditto.
---
libstdc++-v3/scripts/check_performance | 2 +-
.../testsuite/util/native_type/native_hash_map.hpp | 2 +-
.../testsuite/util/native_type/native_hash_multimap.hpp | 4 +---
.../testsuite/util/native_type/native_hash_set.hpp | 2 +-
libstdc++-v3/testsuite/util/native_type/native_map.hpp | 4 ++--
.../testsuite/util/native_type/native_multimap.hpp | 7 ++-----
libstdc++-v3/testsuite/util/native_type/native_set.hpp | 2 +-
7 files changed, 9 insertions(+), 14 deletions(-)
diff --git a/libstdc++-v3/scripts/check_performance
b/libstdc++-v3/scripts/check_performance
index 4831ed71b6f..eb6adbc5ec6 100755
--- a/libstdc++-v3/scripts/check_performance
+++ b/libstdc++-v3/scripts/check_performance
@@ -32,7 +32,7 @@ SH_FLAG="-Wl,--rpath -Wl,$BUILD_DIR/../../gcc \
-Wl,--rpath -Wl,$BUILD_DIR/src/.libs"
ST_FLAG="-static"
LINK=$SH_FLAG
-CXX="$COMPILER $INCLUDES $FLAGS -std=gnu++11 $CXXFLAGS $LINK"
+CXX="$COMPILER $INCLUDES $FLAGS $CXXFLAGS $LINK"
LIBS="./libtestc++.a"
TESTS_FILE="testsuite_files_performance"
diff --git a/libstdc++-v3/testsuite/util/native_type/native_hash_map.hpp
b/libstdc++-v3/testsuite/util/native_type/native_hash_map.hpp
index 1eb9851c886..0c0ecaeaa6b 100644
--- a/libstdc++-v3/testsuite/util/native_type/native_hash_map.hpp
+++ b/libstdc++-v3/testsuite/util/native_type/native_hash_map.hpp
@@ -50,7 +50,7 @@ namespace __gnu_pbds
{
#define PB_DS_BASE_C_DEC \
std::tr1::__unordered_map<Key, Data, Hash_Fn, Eq_Fn, \
- typename _Alloc::template rebind<std::pair<const Key, Data> >::other,
Cache_Hash>
+ typename __gnu_cxx::__alloc_traits<_Alloc>::template rebind_alloc<std::pair<const
Key, Data>>, Cache_Hash>
For C++98 compatibility we need a space between the >> tokens.
template<typename Key,
typename Data,
diff --git a/libstdc++-v3/testsuite/util/native_type/native_hash_multimap.hpp
b/libstdc++-v3/testsuite/util/native_type/native_hash_multimap.hpp
index 35f16de8a1c..f6808aab9d1 100644
--- a/libstdc++-v3/testsuite/util/native_type/native_hash_multimap.hpp
+++ b/libstdc++-v3/testsuite/util/native_type/native_hash_multimap.hpp
@@ -70,9 +70,7 @@ namespace __gnu_pbds
typedef typename base_type::iterator iterator;
typedef typename base_type::const_iterator const_iterator;
- typedef
- typename allocator::template rebind<pair_type>::other::const_reference
- const_reference;
+ typedef const pair_type& const_reference;
native_hash_multimap() : base_type(Init_Size)
{ }
diff --git a/libstdc++-v3/testsuite/util/native_type/native_hash_set.hpp
b/libstdc++-v3/testsuite/util/native_type/native_hash_set.hpp
index 75ebed43110..27bc4d76d3d 100644
--- a/libstdc++-v3/testsuite/util/native_type/native_hash_set.hpp
+++ b/libstdc++-v3/testsuite/util/native_type/native_hash_set.hpp
@@ -50,7 +50,7 @@ namespace __gnu_pbds
{
#define PB_DS_BASE_C_DEC \
std::tr1::__unordered_set<Key, Hash_Fn, Eq_Fn, \
- typename _Alloc::template rebind<Key>::other, Cache_Hash>
+ typename __gnu_cxx::__alloc_traits<_Alloc>::template rebind_alloc<Key>,
Cache_Hash>
template<typename Key,
size_t Init_Size = 8,
diff --git a/libstdc++-v3/testsuite/util/native_type/native_map.hpp
b/libstdc++-v3/testsuite/util/native_type/native_map.hpp
index 958553951b4..1617ed27e20 100644
--- a/libstdc++-v3/testsuite/util/native_type/native_map.hpp
+++ b/libstdc++-v3/testsuite/util/native_type/native_map.hpp
@@ -49,8 +49,8 @@ namespace __gnu_pbds
namespace test
{
#define PB_DS_BASE_C_DEC \
- std::map<Key, Data, Cmp_Fn, \
-typename _Alloc::template rebind<std::pair<const Key, Data > >::other >
+ std::map<Key, Data, Cmp_Fn, \
+ typename __gnu_cxx::__alloc_traits<_Alloc>::template rebind_alloc<std::pair<const
Key, Data>>>
And here.
template<typename Key, typename Data, class Cmp_Fn = std::less<Key>,
typename _Alloc = std::allocator<char> >
diff --git a/libstdc++-v3/testsuite/util/native_type/native_multimap.hpp
b/libstdc++-v3/testsuite/util/native_type/native_multimap.hpp
index 3646de930b4..eea682131cd 100644
--- a/libstdc++-v3/testsuite/util/native_type/native_multimap.hpp
+++ b/libstdc++-v3/testsuite/util/native_type/native_multimap.hpp
@@ -48,7 +48,7 @@ namespace __gnu_pbds
{
#define PB_DS_BASE_C_DEC \
std::multimap<Key, Data, Less_Fn, \
- typename _Alloc::template rebind<std::pair<const Key, Data> >::other>
+ typename __gnu_cxx::__alloc_traits<_Alloc>::template rebind_alloc<std::pair<const
Key, Data>>>
And here.
template<typename Key, typename Data, class Less_Fn = std::less<Key>,
typename _Alloc = std::allocator<char> >
@@ -62,10 +62,7 @@ namespace __gnu_pbds
typedef _Alloc allocator;
- typedef
- typename _Alloc::template rebind<
- std::pair<Key, Data> >::other::const_reference
- const_reference;
+ typedef const std::pair<Key, Data>& const_reference;
typedef typename base_type::iterator iterator;
typedef typename base_type::const_iterator const_iterator;
diff --git a/libstdc++-v3/testsuite/util/native_type/native_set.hpp
b/libstdc++-v3/testsuite/util/native_type/native_set.hpp
index d382a371226..d26e665843a 100644
--- a/libstdc++-v3/testsuite/util/native_type/native_set.hpp
+++ b/libstdc++-v3/testsuite/util/native_type/native_set.hpp
@@ -48,7 +48,7 @@ namespace __gnu_pbds
namespace test
{
#define PB_DS_BASE_C_DEC \
- std::set<Key, Cmp_Fn, typename _Alloc::template rebind<Key>::other>
+ std::set<Key, Cmp_Fn, typename __gnu_cxx::__alloc_traits<_Alloc>::template
rebind_alloc<Key>>
And here.
OK for trunk with those changes, thanks.
template<typename Key, class Cmp_Fn = std::less<Key>,
typename _Alloc = std::allocator<char> >
--
2.54.0
