+2021-04-20 Jonathan Wakely <jwakely@redhat.com>
+
+ Backported from master:
+ 2021-04-20 Jonathan Wakely <jwakely@redhat.com>
+
+ * testsuite/30_threads/semaphore/try_acquire_for.cc: Disable
+ test for targets not using futexes for semaphores.
+ * testsuite/30_threads/semaphore/try_acquire_until.cc: Likewise.
+ * testsuite/30_threads/stop_token/stop_callback/destroy.cc:
+ Disable for all targets.
+
+2021-04-20 Thomas Rodgers <trodgers@redhat.com>
+
+ Backported from master:
+ 2021-04-20 Thomas Rodgers <trodgers@redhat.com>
+
+ * include/Makefile.am: Add new <bits/this_thread_sleep.h> header.
+ * include/Makefile.in: Regenerate.
+ * include/bits/this_thread_sleep.h: New file.
+ * include/bits/atomic_base.h: Adjust all calls
+ to __atomic_wait/__atomic_notify for new call signatures.
+ * include/bits/atomic_timed_wait.h: Extensive rewrite.
+ * include/bits/atomic_wait.h: Likewise.
+ * include/bits/semaphore_base.h: Adjust all calls
+ to __atomic_wait/__atomic_notify for new call signatures.
+ * include/std/atomic: Likewise.
+ * include/std/barrier: Likewise.
+ * include/std/latch: Likewise.
+ * include/std/semaphore: Likewise.
+ * include/std/thread (this_thread::sleep_for)
+ (this_thread::sleep_until): Move to new header.
+ * testsuite/29_atomics/atomic/wait_notify/bool.cc: Simplify
+ test.
+ * testsuite/29_atomics/atomic/wait_notify/generic.cc: Likewise.
+ * testsuite/29_atomics/atomic/wait_notify/pointers.cc: Likewise.
+ * testsuite/29_atomics/atomic_flag/wait_notify/1.cc: Likewise.
+ * testsuite/29_atomics/atomic_float/wait_notify.cc: Likewise.
+ * testsuite/29_atomics/atomic_integral/wait_notify.cc: Likewise.
+ * testsuite/29_atomics/atomic_ref/wait_notify.cc: Likewise.
+
+2021-04-20 Patrick Palka <ppalka@redhat.com>
+
+ Backported from master:
+ 2021-04-20 Patrick Palka <ppalka@redhat.com>
+
+ PR libstdc++/95983
+ * include/bits/stl_iterator.h (__detail::__move_iter_cat):
+ Define.
+ (move_iterator): Derive from the above in C++20 in order to
+ conditionally define iterator_category as per P2259.
+ (move_iterator::__base_cat): No longer used, so remove.
+ (move_iterator::iterator_category): Remove in C++20.
+ (__detail::__common_iter_use_postfix_proxy): Define.
+ (common_iterator::_Proxy): Rename to ...
+ (common_iterator:__arrow_proxy): ... this.
+ (common_iterator::__postfix_proxy): Define as per P2259.
+ (common_iterator::operator->): Adjust.
+ (common_iterator::operator++): Adjust as per P2259.
+ (iterator_traits<common_iterator>::_S_iter_cat): Define.
+ (iterator_traits<common_iterator>::iterator_category): Change as
+ per P2259.
+ (__detail::__counted_iter_value_type): Define.
+ (__detail::__counted_iter_concept): Define.
+ (__detail::__counted_iter_cat): Define.
+ (counted_iterator): Derive from the above three classes in order
+ to conditionally define value_type, iterator_concept and
+ iterator category respectively as per P2259.
+ (counted_iterator::operator->): Define as per P2259.
+ (incrementable_traits<counted_iterator>): Remove as per P2259.
+ (iterator_traits<counted_iterator>): Adjust as per P2259.
+ * include/std/ranges (__detail::__iota_view_iter_cat): Define.
+ (iota_view::_Iterator): Derive from the above in order to
+ conditionally define iterator_category as per P2259.
+ (iota_view::_S_iter_cat): Rename to ...
+ (iota_view::_S_iter_concept): ... this.
+ (iota_view::iterator_concept): Use it to apply LWG 3291 changes.
+ (iota_view::iterator_category): Remove.
+ (__detail::__filter_view_iter_cat): Define.
+ (filter_view::_Iterator): Derive from the above in order to
+ conditionally define iterator_category as per P2259.
+ (filter_view::_Iterator): Move to struct __filter_view_iter_cat.
+ (filter_view::_Iterator::iterator_category): Remove.
+ (transform_view::_Base): Define.
+ (transform_view::__iter_cat): Define.
+ (transform_view::_Iterator): Derive from the above in order to
+ conditionally define iterator_category as per P2259.
+ (transform_view::_Iterator::_Base): Just alias
+ transform_view::_Base.
+ (transform_view::_Iterator::_S_iter_cat): Move to struct
+ transform_view::__iter_cat.
+ (transform_view::_Iterator::iterator_category): Remove.
+ (transform_view::_Sentinel::_Base): Just alias
+ transform_view::_Base.
+ (join_view::_Base): Define.
+ (join_view::_Outer_iter): Define.
+ (join_view::_Inner_iter): Define.
+ (join_view::_S_ref_is_glvalue): Define.
+ (join_view::__iter_cat): Define.
+ (join_view::_Iterator): Derive from it in order to conditionally
+ define iterator_category as per P2259.
+ (join_view::_Iterator::_Base): Just alias join_view::_Base.
+ (join_view::_Iterator::_S_ref_is_glvalue): Just alias
+ join_view::_S_ref_is_glvalue.
+ (join_view::_Iterator::_S_iter_cat): Move to struct
+ transform_view::__iter_cat.
+ (join_view::_Iterator::_Outer_iter): Just alias
+ join_view::_Outer_iter.
+ (join_view::_Iterator::_Inner_iter): Just alias
+ join_view::_Inner_iter.
+ (join_view::_Iterator::iterator_category): Remove.
+ (join_view::_Sentinel::_Base): Just alias join_view::_Base.
+ (__detail::__split_view_outer_iter_cat): Define.
+ (__detail::__split_view_inner_iter_cat): Define.
+ (split_view::_Base): Define.
+ (split_view::_Outer_iter): Derive from __split_view_outer_iter_cat
+ in order to conditionally define iterator_category as per P2259.
+ (split_view::_Outer_iter::iterator_category): Remove.
+ (split_view::_Inner_iter): Derive from __split_view_inner_iter_cat
+ in order to conditionally define iterator_category as per P2259.
+ (split_view::_Inner_iter::_S_iter_cat): Move to
+ __split_view_inner_iter_cat.
+ (split_view::_Inner_iter::iterator_category): Remove.
+ (elements_view::_Base): Define.
+ (elements_view::__iter_cat): Define.
+ (elements_view::_Iterator): Derive from the above in order to
+ conditionall define iterator_category as per P2259.
+ (elements_view::_Iterator::_Base): Just alias
+ elements_view::_Base.
+ (elements_view::_Iterator::_S_iter_concept)
+ (elements_view::_Iterator::iterator_concept): Define as per
+ P2259.
+ (elements_view::_Iterator::iterator_category): Remove.
+ (elements_view::_Sentinel::_Base): Just alias
+ elements_view::_Base.
+ * testsuite/24_iterators/headers/iterator/synopsis_c++20.cc:
+ Adjust constraints on iterator_traits<counted_iterator>.
+ * testsuite/std/ranges/p2259.cc: New test.
+
+2021-04-20 Jonathan Wakely <jwakely@redhat.com>
+
+ Backported from master:
+ 2021-04-20 Jonathan Wakely <jwakely@redhat.com>
+
+ PR libstdc++/100146
+ * include/std/charconv (__cpp_lib_to_chars): Define
+ conditionally.
+ * include/std/version (__cpp_lib_to_chars): Likewise..
+ * testsuite/20_util/from_chars/4.cc: Only check feature test
+ macro, not _GLIBCXX_HAVE_USELOCALE.
+ * testsuite/20_util/from_chars/5.cc: Likewise.
+ * testsuite/20_util/from_chars/6.cc: Likewise.
+ * testsuite/20_util/to_chars/long_double.cc: Likewise.
+
+2021-04-20 Jakub Jelinek <jakub@redhat.com>
+
+ Backported from master:
+ 2021-04-20 Jakub Jelinek <jakub@redhat.com>
+
+ * testsuite/util/testsuite_abi.cc (compare_symbols): If any symbol
+ versions with _IEEE128_ substring are found, set ieee_version_found
+ to true. Ignore missing symbols with _IEEE128_ in version name if
+ !ieee_version_found. Use i->first as version_name instead of
+ i->second.version_name if the latter is empty.
+ * config/abi/post/powerpc64-linux-gnu/baseline_symbols.txt: Update.
+
2021-04-19 H.J. Lu <hjl.tools@gmail.com>
* config/abi/post/x86_64-linux-gnu/x32/baseline_symbols.txt: