Adjust expected errors or skip tests as UNSUPPORTED if -fno-char8_t is
used in the test flags.
libstdc++-v3/ChangeLog:
* testsuite/20_util/integer_comparisons/equal_neg.cc: Use
no-opts selector for errors that depend on -fchar8_t.
* testsuite/20_util/integer_comparisons/greater_equal_neg.cc:
Likewise.
* testsuite/20_util/integer_comparisons/greater_neg.cc:
Likewise.
* testsuite/20_util/integer_comparisons/in_range_neg.cc:
Likewise.
* testsuite/20_util/integer_comparisons/less_equal_neg.cc:
Likewise.
* testsuite/20_util/integer_comparisons/less_neg.cc: Likewise.
* testsuite/20_util/integer_comparisons/not_equal_neg.cc:
Likewise.
* testsuite/21_strings/basic_string/hash/hash_char8_t.cc: Skip
if -fno-char8_t is used.
* testsuite/21_strings/headers/cuchar/functions_std_cxx20.cc:
Likewise.
* testsuite/27_io/basic_ostream/inserters_character/char/deleted.cc:
Likewise.
* testsuite/27_io/basic_ostream/inserters_character/wchar_t/deleted.cc:
Likewise.
* testsuite/27_io/filesystem/path/factory/u8path-depr.cc: Use
char for u8 literal if char8_t is not available.
* testsuite/27_io/headers/iosfwd/synopsis.cc: Check
__cpp_char8_t.
* testsuite/29_atomics/atomic_integral/wait_notify.cc: Likewise.
* testsuite/29_atomics/headers/atomic/types_std_c++20_neg.cc:
Remove check for _GLIBCXX_USE_CHAR8_T.
For 80-bit long double we need to clear the padding bits on
construction.
libstdc++-v3/ChangeLog:
* include/bits/atomic_base.h (__atomic_float::__atomic_float(Fp)):
Clear padding.
* testsuite/29_atomics/atomic_float/compare_exchange_padding.cc:
New test.
Signed-off-by: xndcn <xndchn@gmail.com>
Reviewed-by: Jonathan Wakely <jwakely@redhat.com>
The whole point of these typedefs is to guarantee lock-freedom, so if
the target has no such types, we shouldn't defined the typedefs at all.
libstdc++-v3/ChangeLog:
PR libstdc++/114103
* include/bits/version.def (atomic_lock_free_type_aliases): Add
extra_cond to check for at least one always-lock-free type.
* include/bits/version.h: Regenerate.
* include/std/atomic (atomic_signed_lock_free)
(atomic_unsigned_lock_free): Only use always-lock-free types.
* src/c++20/tzdb.cc (time_zone::_Impl::RulesCounter): Don't use
atomic counter if lock-free aliases aren't available.
* testsuite/29_atomics/atomic/lock_free_aliases.cc: XFAIL for
targets without lock-free word-size compare_exchange.
I don't see why we should rely on __builtin_memset etc. in tests. We can
just include <cstring> and use the public API.
libstdc++-v3/ChangeLog:
* testsuite/23_containers/deque/allocator/default_init.cc: Use
std::memset instead of __builtin_memset.
* testsuite/23_containers/forward_list/allocator/default_init.cc:
Likewise.
* testsuite/23_containers/list/allocator/default_init.cc:
Likewise.
* testsuite/23_containers/map/allocator/default_init.cc:
Likewise.
* testsuite/23_containers/set/allocator/default_init.cc:
Likewise.
* testsuite/23_containers/unordered_map/allocator/default_init.cc:
Likewise.
* testsuite/23_containers/unordered_set/allocator/default_init.cc:
Likewise.
* testsuite/23_containers/vector/allocator/default_init.cc:
Likewise.
* testsuite/23_containers/vector/bool/allocator/default_init.cc:
Likewise.
* testsuite/29_atomics/atomic/compare_exchange_padding.cc:
Likewise.
* testsuite/util/atomic/wait_notify_util.h: Likewise.
These overloads are deprecated in C++20 (and likely to be removed for
C++26). The std::atomic<std::shared_ptr<T>> specialization should be
preferred in new code.
libstdc++-v3/ChangeLog:
* include/bits/shared_ptr_atomic.h (atomic_is_lock_free)
(atomic_load_explicit, atomic_load, atomic_store_explicit)
(atomic_store, atomic_exchange_explicit, atomic_exchange)
(atomic_compare_exchange_strong, atomic_compare_exchange_weak)
(atomic_compare_exchange_strong_explicit)
(atomic_compare_exchange_weak_explicit): Add deprecated
attribute for C++20 and later.
* testsuite/20_util/shared_ptr/atomic/1.cc: Suppress deprecated
warnings.
* testsuite/20_util/shared_ptr/atomic/2.cc: Likewise.
* testsuite/20_util/shared_ptr/atomic/3.cc: Likewise.
* testsuite/29_atomics/atomic/lwg3220.cc: Likewise.
These tests actually use a form of atomic compare and exchange
operation, not just atomic loading and storing. Some targets (not
supported by e.g. libatomic) have atomic loading and storing, but not
compare and exchange, yielding linker errors for missing library
functions.
This change is just for existing uses of
dg-require-thread-fence. It does not fix any other tests
that should also be gated on dg-require-atomic-cmpxchg-word.
* testsuite/29_atomics/atomic/compare_exchange_padding.cc,
testsuite/29_atomics/atomic_flag/clear/1.cc,
testsuite/29_atomics/atomic_flag/cons/value_init.cc,
testsuite/29_atomics/atomic_flag/test_and_set/explicit.cc,
testsuite/29_atomics/atomic_flag/test_and_set/implicit.cc,
testsuite/29_atomics/atomic_ref/compare_exchange_padding.cc,
testsuite/29_atomics/atomic_ref/generic.cc,
testsuite/29_atomics/atomic_ref/integral.cc,
testsuite/29_atomics/atomic_ref/pointer.cc: Replace
dg-require-thread-fence with dg-require-atomic-cmpxchg-word.
A recent patch made __atomic_test_and_set no longer fall
back to emitting non-atomic code, but instead will then emit
a call to __atomic_test_and_set, thereby exposing the need
to gate also this test on support for atomics, similar to
r14-3980-g62b29347c38394.
libstdc++-v3:
* testsuite/29_atomics/atomic_flag/cons/value_init.cc: Add
dg-require-thread-fence.
We can remove { dg-require-effective-target pthread } and allow these
tests non-pthread targets and conditionally adding -pthread only for
pthread targets.
Also remove the { dg-options "-std=gnu++20" } that is no longer needed.
libstdc++-v3/ChangeLog:
* testsuite/29_atomics/atomic_ref/wait_notify.cc: Do not
restrict to pthreads targets.
* testsuite/30_threads/jthread/3.cc: Likewise.
* testsuite/30_threads/semaphore/100806.cc: Likewise.
* testsuite/30_threads/semaphore/try_acquire.cc: Likewise.
* testsuite/30_threads/semaphore/try_acquire_for.cc: Likewise.
* testsuite/30_threads/semaphore/try_acquire_posix.cc: Likewise.
This test fails when run as C++23 because the <bits/stdc++.h> PCH
includes <stdatomic.h> which declares ::memory_order, invalidating the
test's assumptions. Disable PCH so that the test verifies that <atomic>
doesn't declare ::memory_order, as originally intended.
Also fix the using-declaration which would be invalid even if the type
was declared in the global namespace, and adjust the expected error.
libstdc++-v3/ChangeLog:
* testsuite/29_atomics/headers/atomic/types_std_c++2a_neg.cc:
Fix test to work for C++23 and C++26 too.
Some targets like arm-eabi with newlib and default settings rely on
__sync_synchronize() to ensure synchronization. Newlib does not
implement it by default, to make users aware they have to take special
care.
This makes a few tests fail to link.
This patch requires the missing thread-fence effective target in the
tests that need it, making them UNSUPPORTED instead of FAIL and
UNRESOLVED.
2023-09-10 Christophe Lyon <christophe.lyon@linaro.org>
libstdc++-v3/
* testsuite/29_atomics/atomic/compare_exchange_padding.cc: Likewise.
* testsuite/29_atomics/atomic/cons/value_init.cc: Likewise.
* testsuite/29_atomics/atomic_float/value_init.cc: Likewise.
* testsuite/29_atomics/atomic_integral/cons/value_init.cc: Likewise.
* testsuite/29_atomics/atomic_ref/compare_exchange_padding.cc: Likewise.
* testsuite/29_atomics/atomic_ref/generic.cc: Likewise.
* testsuite/29_atomics/atomic_ref/integral.cc: Likewise.
* testsuite/29_atomics/atomic_ref/pointer.cc: Likewise.
We need to use a loop in std::atomic_ref::compare_exchange_strong in
order to properly implement the C++20 requirement that padding bits do
not participate when checking the value for equality. The variable being
modified by a std::atomic_ref might have an initial value with non-zero
padding bits, so when the __atomic_compare_exchange built-in returns
false we need to check whether that was only because of non-equal
padding bits that are not part of the value representation. If the value
bits differ, it's just a failed compare-exchange. If the value bits are
the same, we need to retry the __atomic_compare_exchange using the value
that was just read by the previous failed call. As noted in the
comments, it's possible for that second try to also fail due to another
thread storing the same value but with differences in padding.
Because it's undefined to access a variable directly while it's held by
a std::atomic_ref, and because std::atomic_ref will only ever store
values with zeroed padding, we know that padding bits will never go from
zero to non-zero during the lifetime of a std::atomic_ref. They can only
go from an initial non-zero state to zero. This means the loop will
terminate, rather than looping indefinitely as padding bits flicker on
and off. In theory users could call __atomic_store etc. directly and
write a value with non-zero padding bits, but we don't need to support
that. Users doing that should ensure they do not write non-zero padding,
to be compatibile with our std::atomic_ref's invariants.
This isn't a problem for std::atomic<T>::compare_exchange_strong because
the initial value (and all later stores to the variable) are performed
by the library, so we ensure that stored values always have padding bits
cleared. That means we can simply clear the padding bits of the
'expected' value and we will be comparing two values with equal padding
bits. This means we don't need the loop for std::atomic, so update the
__atomic_impl::__compare_exchange function to take a bool parameter that
says whether it's being used by std::atomic_ref. If not, we can use a
simpler, non-looping implementation.
libstdc++-v3/ChangeLog:
PR libstdc++/111077
* include/bits/atomic_base.h (__atomic_impl::__compare_exchange):
Add _AtomicRef non-type template parameter and use a loop if it
is true.
(__atomic_impl::compare_exchange_weak): Add _AtomicRef NTTP.
(__atomic_impl::compare_exchange_strong): Likewise.
(atomic_ref::compare_exchange_weak): Use true for NTTP.
(atomic_ref::compare_exchange_strong): Use true for NTTP.
* testsuite/29_atomics/atomic_ref/compare_exchange_padding.cc:
Fix test to not rely on atomic_ref::load() to return an object
with padding preserved.
The _GLIBCXX_USE_C99_STDINT_TR1 macro (and the comments about it in
acinclude.m4 and config.h) are misleading when it is also used for
<stdint>, not only <tr1/stdint>. It is also wrong, because the
configure checks for TR1 use -std=c++98 and a target might define
uint32_t etc. for C++11 but not for C++98.
Add a separate configure check for the <stdint.h> types using -std=c++11
for the checks. Use the result of that separate check in <cstdint> and
most other places that still depend on the macro (many uses of that
macro have been removed already). The remaining uses of the STDINT_TR1
macro are really for TR1, or are in the src/c++11/compatibility-*.cc
files, where we don't want/need to change the condition they depend on
(if those symbols were only exported when <stdint.h> types were
available for -std=c++98, then that's the condition we should continue
to use for whether to export the compat symbols now).
Make similar changes for the related _GLIBCXX_USE_C99_INTTYPES_TR1 and
_GLIBCXX_USE_C99_INTTYPES_WCHAR_T_TR1 macros, adding new macros for
non-TR1 uses.
libstdc++-v3/ChangeLog:
* acinclude.m4 (GLIBCXX_USE_C99): Check for <stdint.h> types in
C++11 mode and define _GLIBCXX_USE_C99_STDINT. Check for
<inttypes.h> features in C++11 mode and define
_GLIBCXX_USE_C99_INTTYPES and _GLIBCXX_USE_C99_INTTYPES_WCHAR_T.
* config.h.in: Regenerate.
* configure: Regenerate.
* doc/doxygen/user.cfg.in (PREDEFINED): Add new macros.
* include/bits/chrono.h: Check _GLIBCXX_USE_C99_STDINT instead
of _GLIBCXX_USE_C99_STDINT_TR1.
* include/c_compatibility/inttypes.h: Check
_GLIBCXX_USE_C99_INTTYPES and _GLIBCXX_USE_C99_INTTYPES_WCHAR_T
instead of _GLIBCXX_USE_C99_INTTYPES_TR1 and
_GLIBCXX_USE_C99_INTTYPES_WCHAR_T_TR1.
* include/c_compatibility/stdatomic.h: Check
_GLIBCXX_USE_C99_STDINT instead of _GLIBCXX_USE_C99_STDINT_TR1.
* include/c_compatibility/stdint.h: Likewise.
* include/c_global/cinttypes: Check _GLIBCXX_USE_C99_INTTYPES
and _GLIBCXX_USE_C99_INTTYPES_WCHAR_T instead of
_GLIBCXX_USE_C99_INTTYPES_TR1 and
_GLIBCXX_USE_C99_INTTYPES_WCHAR_T_TR1.
* include/c_global/cstdint: Check _GLIBCXX_USE_C99_STDINT
instead of _GLIBCXX_USE_C99_STDINT_TR1.
* include/std/atomic: Likewise.
* src/c++11/cow-stdexcept.cc: Likewise.
* testsuite/29_atomics/headers/stdatomic.h/c_compat.cc:
Likewise.
* testsuite/lib/libstdc++.exp (check_v3_target_cstdint):
Likewise.
Since r9-2028-g8ba7f29e3dd064 we've defined most of <cstdint>
unconditionally, so we can do the same for most of the std::atomic
aliases such as std::atomic_int_least32_t.
The only aliases that need to depend on _GLIBCXX_USE_C99_STDINT_TR1 are
the ones for the integer types that are not guaranteed to be defined,
e.g. std::atomic_int32_t.
libstdc++-v3/ChangeLog:
* include/std/atomic (atomic_int_least8_t, atomic_uint_least8_t)
(atomic_int_least16_t, atomic_uint_least16_t)
(atomic_int_least32_t, atomic_uint_least32_t)
(atomic_int_least64_t, atomic_uint_least64_t)
(atomic_int_fast16_t, atomic_uint_fast16_t)
(atomic_int_fast32_t, atomic_uint_fast32_t)
(atomic_int_fast64_t, atomic_uint_fast64_t)
(atomic_intmax_t, atomic_uintmax_t): Define unconditionally.
* testsuite/29_atomics/headers/stdatomic.h/c_compat.cc: Adjust.
At some point, <charconv> was added to the non-hosted bit of the C++17
block, which induced failures in many tests.
In addition, some tests also lacked a dg-require-effective-target hosted
tag.
libstdc++-v3/ChangeLog:
* include/precompiled/stdc++.h (C++17): Don't double-include
<charconv>, once with wrong conditions.
* testsuite/18_support/96817.cc: Require hosted.
* testsuite/18_support/bad_exception/59392.cc: Ditto.
* testsuite/20_util/scoped_allocator/108952.cc: Ditto.
* testsuite/20_util/uses_allocator/lwg3527.cc: Ditto.
* testsuite/29_atomics/atomic/operators/pointer_partial_void.cc:
Ditto.
This patch adds -
atomic_flag_test
atomic_flag_test_explicit
Which were missed when commit 491ba6 introduced C++20 atomic flag
test.
libstdc++-v3/ChangeLog:
PR libstdc++/103934
* include/std/atomic (atomic_flag_test): Add.
(atomic_flag_test_explicit): Add.
* testsuite/29_atomics/atomic_flag/test/explicit.cc: Add
test case to cover missing atomic_flag free functions.
* testsuite/29_atomics/atomic_flag/test/implicit.cc:
Likewise.
The following patch is partial support for std::float{16,32,64,128}_t
and std::bfloat16_t in libstdc++.
https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2022/p1467r9.html
says that <ostream>, <istream>, <charconv> and <complex>
need changes toom, but that isn't implemented so far.
In <cmath> the only thing missing I'm aware of is
std::nextafter std::float16_t and std::bfloat16_t overloads (I think
we probably need to implement that out of line somewhere, or inline? - might
need inline asm barriers) and std::nexttoward overloads (those are
intentional, you said there is a LWG issue about that).
Also, this patch has the glibc 2.26+ std::float128_t support for platforms
where long double isn't IEEE quad format temporarily disabled
because it depends on
https://gcc.gnu.org/pipermail/gcc-patches/2022-October/603665.html
changes which aren't in yet.
The patch also doesn't include any testcases to cover the <type_traits>
changes, it isn't clear to me where to put that.
2022-10-18 Jakub Jelinek <jakub@redhat.com>
PR c++/106652
* include/std/stdfloat: New file.
* include/std/numbers (__glibcxx_numbers): Define and use it
for __float128 explicit instantiations as well as
_Float{16,32,64,128} and __gnu_cxx::__bfloat16_t.
* include/std/atomic (atomic<_Float16>, atomic<_Float32>,
atomic<_Float64>, atomic<_Float128>, atomic<__gnu_cxx::__bfloat16_t>):
New explicit instantiations.
* include/std/type_traits (__is_floating_point_helper<_Float16>,
__is_floating_point_helper<_Float32>,
__is_floating_point_helper<_Float64>,
__is_floating_point_helper<_Float128>,
__is_floating_point_helper<__gnu_cxx::__bfloat16_t>): Likewise.
* include/std/limits (__glibcxx_concat3_, __glibcxx_concat3,
__glibcxx_float_n): Define.
(numeric_limits<_Float16>, numeric_limits<_Float32>,
numeric_limits<_Float64>, numeric_limits<_Float128>,
numeric_limits<__gnu_cxx::__bfloat16_t>): New explicit instantiations.
* include/bits/std_abs.h (abs): New overloads for
_Float{16,32,64,128} and __gnu_cxx::__bfloat16_t.
* include/bits/c++config (_GLIBCXX_LDOUBLE_IS_IEEE_BINARY128): Define
if long double is IEEE quad.
(__gnu_cxx::__bfloat16_t): New using.
* include/c_global/cmath (acos, asin, atan, atan2, ceil, cos, cosh,
exp, fabs, floor, fmod, frexp, ldexp, log, log10, modf, pow, sin,
sinh, sqrt, tan, tanh, fpclassify, isfinite, isinf, isnan, isnormal,
signbit, isgreater, isgreaterequal, isless, islessequal,
islessgreater, isunordered, acosh, asinh, atanh, cbrt, copysign, erf,
erfc, exp2, expm1, fdim, fma, fmax, fmin, hypot, ilogb, lgamma,
llrint, llround, log1p, log2, logb, lrint, lround, nearbyint,
nextafter, remainder, rint, round, scalbln, scalbn, tgamma, trunc,
lerp): New overloads with _Float{16,32,64,128} or
__gnu_cxx::__bfloat16_t types.
* config/os/gnu-linux/os_defines.h (_GLIBCXX_HAVE_FLOAT128_MATH):
Prepare for definition if glibc 2.26 and later implements *f128 APIs
but comment out the actual definition for now.
* include/ext/type_traits.h (__promote<_Float16>, __promote<_Float32>,
__promote<_Float64>, __promote<_Float128>,
__promote<__gnu_cxx::__bfloat16_t>): New specializations.
* include/Makefile.am (std_headers): Add stdfloat.
* include/Makefile.in: Regenerated.
* include/precompiled/stdc++.h: Include stdfloat.
* testsuite/18_support/headers/stdfloat/types_std.cc: New test.
* testsuite/18_support/headers/limits/synopsis_cxx23.cc: New test.
* testsuite/26_numerics/headers/cmath/c99_classification_macros_c++23.cc:
New test.
* testsuite/26_numerics/headers/cmath/functions_std_c++23.cc: New test.
* testsuite/26_numerics/numbers/4.cc: New test.
* testsuite/29_atomics/atomic_float/requirements_cxx23.cc: New test.
This test was written assuming that std::atomic_ref clears its target's
padding on construction, but that could introduce data races. Change the
test to store a value after construction and check that its padding is
cleared by the store.
libstdc++-v3/ChangeLog:
* testsuite/29_atomics/atomic_ref/compare_exchange_padding.cc:
Store value with non-zero padding bits after construction.
This change implements P0528 which requires that padding bits not
participate in atomic compare exchange operations. All arguments to the
generic template are 'sanitized' by the __builtin_clear_padding intrinsic
before they are used in comparisons. This requires that any stores
also sanitize the incoming value.
Co-authored-by: Jakub Jelinek <jakub@redhat.com>
Co-authored-by: Jonathan Wakely <jwakely@redhat.com>
Signed-off-by: Thomas Rodgers <trodgers@redhat.com>
libstdc++-v3/ChangeLog:
* include/bits/atomic_base.h (__atomic_impl::__maybe_has_padding):
New function.
(__atomic_impl::clear_padding): Likewise.
(__atomic_impl::__compare_exchange): Likewise.
(__atomic_impl::compare_exchange_weak): Delegate to
__compare_exchange.
(__atomic_impl::compare_exchange_strong): Likewise.
* include/std/atomic (atomic<T>::atomic(T)): Clear padding when
possible in a constexpr function.
(atomic::store): Clear padding.
(atomic::exchange): Likewise.
(atomic::compare_exchange_weak): Use __compare_exchange.
(atomic::compare_exchange_strong): Likewise.
* testsuite/29_atomics/atomic/compare_exchange_padding.cc: New
test.
* testsuite/29_atomics/atomic_ref/compare_exchange_padding.cc:
New test.
This is LWG 3220 which is about to become Tentatively Ready.
libstdc++-v3/ChangeLog:
* include/std/atomic (__atomic_val_t): Use __type_identity_t
instead of atomic<T>::value_type, as per LWG 3220.
* testsuite/29_atomics/atomic/lwg3220.cc: New test.
<recording this here for future reference>
PR102994 "atomics: std::atomic<ptr>::wait is not marked const" raises the
issue that the current libstdc++ implementation marks the notify members
const, the implementation strategy used by libstdc++, as well as libc++
and the Microsoft STL, do not require the atomic to be mutable (it is hard
to conceive of a desirable implementation approach that would require it).
The original paper proposing the wait/notify functionality for atomics
(p1185) also had these members marked const for the first three revisions,
but that was changed without explanation in r3 and subsequent revisions of
the paper.
After raising the issue to the authors of p1185 and the author of the
libc++ implementation, the consensus seems to be "meh, it's harmless" so
there seems little appetite for an LWG issue to revisit the subject.
This patch changes the libstdc++ implementation to be in agreement with
the standard by removing const from those notify_one/notify_all members.
libstdc++-v3/ChangeLog:
PR libstdc++/102994
* include/bits/atomic_base.h (atomic_flag::notify_one,
notify_all): Remove const qualification.
(__atomic_base::notify_one, notify_all): Likewise.
* include/std/atomic (atomic<bool>::notify_one, notify_all):
Likewise.
(atomic::notify_one, notify_all): Likewise.
(atomic<T*>::notify_one, notify_all): Likewise.
(atomic_notify_one, atomic_notify_all): Likewise.
* testsuite/29_atomics/atomic/wait_notify/102994.cc: Adjust test
to account for change in notify_one/notify_all signature.
This function (and the explicit memory over version) are present in both
C++ <atomic> and C <stdatomic.h>, so should be in C++ <stdatomic.h> too.
There is a library issue incoming for this, but the resolution is
obvious.
libstdc++-v3/ChangeLog:
* include/c_compatibility/stdatomic.h (atomic_fetch_xor): Add
using-declaration.
(atomic_fetch_xor_explicit): Likewise.
* testsuite/29_atomics/headers/stdatomic.h/c_compat.cc: Check
arithmetic and logical operations for atomic_int.
This adds the C++23 <stdatomic.h> header, as proposed by P0943R6, for
compatibility with C code.
There are still some ABI differences between atomic_xxx in C and C++
std::atomic_xxx in C++, so this only provides source compatibility, not
binary compatibility.
libstdc++-v3/ChangeLog:
* include/Makefile.am: Install new header.
* include/Makefile.in: Regenerate.
* include/c_compatibility/stdatomic.h: New file.
* testsuite/29_atomics/headers/stdatomic.h/c_compat.cc: New test.
This was an oversight in the original commit adding wait/notify
to atomic<T>.
libstdc++-v3/ChangeLog:
PR libstdc++/102994
* include/bits/atomic_base.h (__atomic_base<_PTp*>::wait()):
Add const qualifier.
* include/std/atomic (atomic<_Tp*>::wait(), atomic_wait()):
Likewise.
* testsuite/29_atomics/atomic/wait_notify/102994.cc:
New test.
Remove UB in atomic_ref/wait_notify test.
Signed-off-by: Thomas Rodgers <trodgers@redhat.com>
libstdc++-v3/ChangeLog:
PR libstdc++/101761
* testsuite/29_atomics/atomic_ref/wait_notify.cc (test): Use
va and vb as arguments to wait/notify, remove unused bb local.
Fixes a regression on arm32 targets.
libstdc++-v3/ChangeLog:
* testsuite/29_atomics/atomic_ref/wait_notify.cc: Guard
test logic with constexpr check for is_always_lock_free.
libstdc++-v3/ChangeLog:
PR libstdc++/100889
* include/bits/atomic_base.h (atomic_ref<_Tp*>::wait):
Change parameter type from _Tp to _Tp*.
* testsuite/29_atomics/atomic_ref/wait_notify.cc: Extend
coverage of types tested.
Fixes https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100334
libstdc++-v3/ChangeLog:
* include/bits/atomic_wait.h (__waiter::_M_do_wait_v): loop
until value change observed.
(__waiter_base::_M_laundered): New member.
(__waiter_base::_M_notify): Check _M_laundered to determine
whether to wake one or all.
(__detail::__atomic_compare): Return true if call to
__builtin_memcmp() == 0.
(__waiter_base::_S_do_spin_v): Adjust predicate.
* testsuite/29_atomics/atomic/wait_notify/100334.cc: New
test.
gcc on ia32 miscompiles various atomics involving floating point,
unfortunately I'm afraid it is too late to fix that for 11.1 and
as I'm quite lost on it, it might take a while for 12 too
(disabling all the 8 peephole2s would be easiest, but then we'd
run into optimization regressions).
While 1.cc just FAILs, with dejagnu 1.6.1 wait_notify.cc hangs the
make check even after the timeout fires. The following patch therefore
xfails the former and skips the latter.
Tested on x86_64-linux where
make check RUNTESTFLAGS='conformance.exp=atomic_float/*.cc'
is still
=== libstdc++ Summary ===
# of expected passes 8
and on i686-linux, where it is now
=== libstdc++ Summary ===
# of expected passes 5
# of expected failures 1
# of unsupported tests 1
2021-04-22 Jakub Jelinek <jakub@redhat.com>
PR target/100182
* testsuite/29_atomics/atomic_float/1.cc: Add dg-xfail-run-if for
ia32.
* testsuite/29_atomics/atomic_float/wait_notify.cc: Add dg-skip-if for
ia32.
This is a substantial rewrite of the atomic wait/notify (and timed wait
counterparts) implementation.
The previous __platform_wait looped on EINTR however this behavior is
not required by the standard. A new _GLIBCXX_HAVE_PLATFORM_WAIT macro
now controls whether wait/notify are implemented using a platform
specific primitive or with a platform agnostic mutex/condvar. This
patch only supplies a definition for linux futexes. A future update
could add support __ulock_wait/wake on Darwin, for instance.
The members of __waiters were lifted to a new base class. The members
are now arranged such that overall sizeof(__waiter_pool_base) fits in
two cache lines (on platforms with at least 64 byte cache lines). The
definition will also use destructive_interference_size for this if it is
available.
The __waiters type is now specific to untimed waits, and is renamed to
__waiter_pool. Timed waits have a corresponding __timed_waiter_pool
type. Much of the code has been moved from the previous __atomic_wait()
free function to the __waiter_base template and a __waiter derived type
is provided to implement the un-timed wait operations. A similar change
has been made to the timed wait implementation.
The __atomic_spin code has been extended to take a spin policy which is
invoked after the initial busy wait loop. The default policy is to
return from the spin. The timed wait code adds a timed backoff spinning
policy. The code from <thread> which implements this_thread::sleep_for,
sleep_until has been moved to a new <bits/std_thread_sleep.h> header
which allows the thread sleep code to be consumed without pulling in the
whole of <thread>.
The entry points into the wait/notify code have been restructured to
support either -
* Testing the current value of the atomic stored at the given address
and waiting on a notification.
* Applying a predicate to determine if the wait was satisfied.
The entry points were renamed to make it clear that the wait and wake
operations operate on addresses. The first variant takes the expected
value and a function which returns the current value that should be used
in comparison operations, these operations are named with a _v suffix
(e.g. 'value'). All atomic<_Tp> wait/notify operations use the first
variant. Barriers, latches and semaphores use the predicate variant.
This change also centralizes what it means to compare values for the
purposes of atomic<T>::wait rather than scattering through individual
predicates.
This change also centralizes the repetitive code which adjusts for
different user supplied clocks (this should be moved elsewhere
and all such adjustments should use a common implementation).
This change also removes the hashing of the pointer and uses
the pointer value directly for indexing into the waiters table.
libstdc++-v3/ChangeLog:
* 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.
-fcf-protection is automatically enabled in libstdc++ on Linux/x86.
Starting from
commit 77d372abec
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Thu Jan 14 05:56:46 2021 -0800
x86: Error on -fcf-protection with incompatible target
GCC issues an error on -fcf-protection with incompatible target:
... -fcf-protection ... libstdc++-v3/testsuite/29_atomics/atomic_flag/test_and_set/explicit-hle.cc -m32 -O2 -g0 -fno-exceptions -fno-asynchronous-unwind-tables -march=i486 ...
cc1plus: error: '-fcf-protection' is not compatible with this target
FAIL: 29_atomics/atomic_flag/test_and_set/explicit-hle.cc (test for excess errors)
Add -fcf-protection=none to -march=i486 to compile explicit-hle.cc.
* testsuite/29_atomics/atomic_flag/test_and_set/explicit-hle.cc:
Add -fcf-protection=none to -march=i486.
Adds __cpp_lib_atomic_wait feature test macro which was overlooked in
the initial commit of this feature. Replaces uses of
_GLIBCXX_HAVE_ATOMIC_WAIT.
libstdc++-v3/ChangeLog:
* include/bits/atomic_base.h: Replace usage of
_GLIBCXX_HAVE_ATOMIC_WAIT with __cpp_lib_atomic_wait.
* include/bits/atomic_timed_wait.h: Likewise.
* include/bits/atomic_wait.h: Define __cpp_lib_atomic_wait
feature test macro.
* include/bits/semaphore_base.h: Replace usage of
_GLIBCXX_HAVE_ATOMIC_WAIT with __cpp_lib_atomic_wait.
* include/std/atomic: Likewise.
* include/std/latch: Likewise.
* include/std/semaphore: Likewise.
* include/std/version: Define __cpp_lib_atomic wait
feature test macro and replace usage of
_GLIBCXX_HAVE_ATOMIC_WAIT.
* testsuite/29_atomics/atomic/wait_notify/1.cc: New test.
* testsuite/29_atomics/atomic/wait_notify/2.cc: Likewise.
The missed notifications fixed in r11-5383 also happen in some other
tests which have similar code.
libstdc++-v3/ChangeLog:
PR libstdc++/97936
* testsuite/29_atomics/atomic/wait_notify/bool.cc: Fix missed
notifications by making the new thread wait until the parent
thread is waiting on the condition variable.
* testsuite/29_atomics/atomic/wait_notify/pointers.cc: Likewise.
* testsuite/29_atomics/atomic_flag/wait_notify/1.cc: Likewise.
* testsuite/29_atomics/atomic_ref/wait_notify.cc: Likewise.
