The LWG 3506 issue ads allocator-extended versions of the constructors
that take iterator arguments.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
* include/bits/stl_queue.h (priority_queue): Add
allocator-extended overloads for constructors taking iterator.
* testsuite/23_containers/priority_queue/lwg3506.cc: New test.
The LWG 3529 issue changes to use two overloads instead of one with a
default argument, so that the sequence can be initialized directly with
the iterator range when no sequence argument is provided.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
* include/bits/stl_queue.h (priority_queue): Construct sequence
from iterators when no sequence argument is present (LWG 3529).
* testsuite/23_containers/priority_queue/lwg3529.cc: New test.
The LWG 3522 issue constrains all constructors of container adaptors
that have InputIterator parameters.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
* include/bits/stl_queue.h (priority_queue): Constrain
constructors with InputIterator parameters (LWG 3522).
* testsuite/23_containers/priority_queue/lwg3522.cc: New test.
libstdc++-v3/ChangeLog:
* include/bits/ranges_base.h (ranges::distance): Split overload
into two (LWG 3392).
* testsuite/24_iterators/range_operations/lwg3392.cc: New test.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
* include/std/variant (__do_visit): Use variant_npos instead of
literal -1 that requires a narrowing conversion.
This change is inspired by the suggestion in
http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1715r0.html
The new std::__conditional_t alias template is functionally equivalent
to std::conditional_t but should be more efficient to compile, due to
only ever instantiating two specializations (std::__conditional<true>
and std::__conditional<false>) rather than a new specialization for
every use of std::conditional.
The new alias template is also available in C++11, unlike the C++14
std::conditional_t alias.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
* include/std/type_traits (__conditional): New class template
for internal uses of std::conditional.
(__conditional_t): New alias template to replace conditional_t.
(__and_, __or_, __result_of_memfun, __result_of_memobj): Use
__conditional_t instead of conditional::type.
* include/bits/atomic_base.h (__atomic_impl::_Diff): Likewise.
* include/bits/hashtable.h (_Hashtable): Likewise.
* include/bits/hashtable_policy.h (_Node_iterator, _Insert_base)
(_Local_iterator): Likewise. Replace typedefs with
using-declarations.
* include/bits/move.h (move_if_noexcept): Use __conditional_t.
* include/bits/parse_numbers.h (_Select_int_base): Likewise.
* include/bits/ptr_traits.h (__make_not_void): Likewise.
* include/bits/ranges_algobase.h (__copy_or_move_backward)
(__copy_or_move): Likewise.
* include/bits/ranges_base.h (borrowed_iterator_t): Likewise.
* include/bits/ranges_util.h (borrowed_subrange_t): Likewise.
* include/bits/regex_compiler.h (_BracketMatcher): Use
__conditional_t. Replace typedefs with using-declarations.
* include/bits/shared_ptr_base.h (__shared_count): Use
__conditional_t.
* include/bits/stl_algobase.h (__copy_move, __copy_move_backward):
Likewise.
* include/bits/stl_iterator.h (__detail::__clamp_iter_cat)
(reverse_iterator::iterator_concept)
(__make_move_if_noexcept_iterator)
(iterator_traits<common_iterator<_It, _Sent>>)
(iterator_traits<counted_iterator<_It>>): Likewise.
* include/bits/stl_pair.h (_PCC, pair::operator=): Likewise.
* include/bits/stl_tree.h (_Rb_tree::insert_return_type)
(_Rb_tree::_M_clone_node): Likewise.
* include/bits/unique_ptr.h (unique_ptr(unique_ptr<U,E>&&)):
Likewise.
* include/bits/uses_allocator.h (__uses_alloc): Likewise.
(__is_uses_allocator_predicate): Likewise.
* include/debug/functions.h (__foreign_iterator_aux2): Likewise.
* include/experimental/any (any::_Manager, __any_caster):
Likewise.
* include/experimental/executor (async_completion): Likewise.
* include/experimental/functional (__boyer_moore_base_t):
Likewise.
* include/std/any (any::_Manager): Likewise.
* include/std/functional (__boyer_moore_base_t): Likewise.
* include/std/ranges (borrowed_iterator_t)
(borrowed_subrange_t, __detail::__maybe_present_t)
(__detail::__maybe_const_t, split_view): Likewise.
* include/std/tuple (__empty_not_final, tuple::operator=):
Likewise.
* include/std/variant (__detail::__variant::__get_t): Likewise.
GCC does not do a good job of optimizing the table of function pointers
used for variant visitation. This avoids using the table for the common
case of visiting a single variant with a small number of alternative
types. Instead we use:
switch(v.index())
{
case 0: return visitor(get<0>(v));
case 1: return visitor(get<1>(v));
...
}
It's not quite that simple, because get<1>(v) is ill-formed if the
variant only has one alternative, and similarly for each get<N>. We
need to ensure each case only applies the visitor if the index is in
range for the actual type we're dealing with, and tell the compiler that
the case is unreachable otherwise. We also need to invoke the visitor
via the __gen_vtable_impl::__visit_invoke function, to handle the raw
visitation cases used to implement std::variant assignments and
comparisons.
Because that gets quite verbose and repetitive, a macro is used to stamp
out the cases.
We also need to handle the valueless_by_exception case, but only for raw
visitation, because std::visit already checks for it before calling
__do_visit.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
PR libstdc++/78113
* include/std/variant (__do_visit): Use a switch when we have a
single variant with a small number of alternatives.
Implement the changes from P2162R2 (as a DR for C++17).
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
PR libstdc++/90943
* include/std/variant (__cpp_lib_variant): Update value.
(__detail::__variant::__as): New helpers implementing the
as-variant exposition-only function templates.
(visit, visit<R>): Use __as to upcast the variant parameters.
* include/std/version (__cpp_lib_variant): Update value.
* testsuite/20_util/variant/visit_inherited.cc: New test.
This uses C++11 features to simplify the definition of the
__normal_iterator constructor that allows converting from iterator to
const_iterator. The previous definition relied on _Container::pointer
which is present in std::vector and std::basic_string, but is not
actually part of the container requirements.
Removing the use of _Container::pointer and defining it in terms of
is_convertible allows __normal_iterator to be used with new container
types which do not define a pointer member. Specifically, this will
allow it to be used in std::basic_stacktrace.
In theory this will enable some conversions which were not previously
permitted, for example __normal_iterator<volatile T*, vector<T>> can
now be converted to __normal_iterator<const volatile T*, vector<T>>.
In practice this doesn't matter because the library never uses such
types. In any case, allowing those conversions is consistent with
the corresponding constructors of std::reverse_iterator and
std::move_iterator.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
* include/bits/stl_iterator.h (__normal_iterator): Simplify
converting constructor and do not require _Container::pointer.
The move constructor for the "fully-dynamic" COW string is not noexcept,
because it allocates a new empty string rep for the moved-from string.
However, there is no need to do that, because the moved-from string does
not have to be left empty. Instead, implement move construction for the
fully-dynamic case as a reference count increment, so the string is
shared.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
* include/bits/cow_string.h [_GLIBCXX_FULLY_DYNAMIC_STRING]
(basic_string(basic_string&&)): Add noexcept and avoid
allocation, by sharing rep with the rvalue string.
This adds a noexcept-specifier to each constructor and assignment
operator of std::reverse_iterator so that they are noexcept when the
corresponding operation on the underlying iterator is noexcept.
The std::reverse_iterator class template already requires that the
operations on the underlying type are valid, so we don't need to use the
std::is_nothrow_xxx traits to protect against errors when the expression
isn't even valid. We can just use a noexcept operator to test if the
expression can throw, without the overhead of redundantly checking if
the initialization/assignment would be valid.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
PR libstdc++/94418
* include/bits/stl_iterator.h (reverse_iterator): Use
conditional noexcept on constructors and assignment operators.
* testsuite/24_iterators/reverse_iterator/noexcept.cc: New test.
The vector<bool>::shrink_to_fit() implementation will allocate new
storage even if the vector is empty. That then leads to the
end-of-storage pointer being non-null and equal to the _M_start._M_p
pointer, which means that _M_end_addr() has undefined behaviour.
The fix is to stop doing a useless zero-sized allocation in
shrink_to_fit(), so that _M_start._M_p and _M_end_of_storage are both
null after an empty vector shrinks.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
PR libstdc++/100153
* include/bits/vector.tcc (vector<bool>::_M_shrink_to_fit()):
When size() is zero just deallocate and reset.
The compiler doesn't know about the precondition of std::clamp that
(hi < lo) is false, and so can't optimize as well as we'd like. By using
std::min and std::max we help the compiler.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
PR libstdc++/96733
* include/bits/stl_algo.h (clamp): Use std::min and std::max.
The regex_constants::multiline constant is defined for non-strict C++11
and C++14 modes, on the basis that the feature is a DR (even though it
was really a new feature addition to C++17 and probably shouldn't have
gone through the issues list).
This makes the basic_regex::multiline constant defined consistently with
the regex_constants::multiline one.
For strict C++11 and C++14 mode we don't define them, because multiline
is not a reserved name in those standards.
libstdc++-v3/ChangeLog:
* include/bits/regex.h (basic_regex::multiline): Define for
non-strict C++11 and C++14 modes.
* include/bits/regex_constants.h (regex_constants::multiline):
Add _GLIBCXX_RESOLVE_LIB_DEFECTS comment.
libstdc++-v3/ChangeLog:
* include/bits/stream_iterator.h (istream_iterator): Add
noexcept to constructors and non-throwing member functions and
friend functions.
(ostream_iterator): Likewise.
The recent changes to the _GLIBCXX_CONCEPT_CHECKS checks for forward
iterators don't work for vector<bool> iterators in debug mode, because
the _Safe_iterator specializations don't match the special cases I added
for _Bit_iterator and _Bit_const_iterator.
This refactors the _ForwardIteratorReferenceConcept class template to
identify vector<bool> iterators using a new trait, which also works for
debug iterators.
libstdc++-v3/ChangeLog:
* include/bits/boost_concept_check.h (_Is_vector_bool_iterator):
New trait to identify vector<bool> iterators, including debug
ones.
(_ForwardIteratorReferenceConcept): Add default template
argument using _Is_vector_bool_iterator and use it in partial
specialization for the vector<bool> cases.
(_Mutable_ForwardIteratorReferenceConcept): Likewise.
* testsuite/24_iterators/operations/prev_neg.cc: Adjust dg-error
line number.
The current std::list::merge code calls size() before starting to merge
any elements, so that the _M_size members can be updated after the merge
finishes. The work is done in a try-block so that the sizes can still be
updated in an exception handler if any element comparison throws.
The _M_size members only exist for the cxx11 ABI, so the initial call to
size() and the try-catch are only needed for that ABI. For the old ABI
the size() call performs an O(N) list traversal to get a value that
isn't even used, and catching exceptions just to rethrow them isn't
needed either.
This refactors the merge functions to remove the try-catch block and use
an RAII type instead. For the cxx11 ABI that type's destructor updates
the list sizes, and for the old ABI it's a no-op.
libstdc++-v3/ChangeLog:
* include/bits/list.tcc (list::merge): Remove call to size() and
try-catch block. Use _Finalize_merge instead.
* include/bits/stl_list.h (list::_Finalize_merge): New
scope guard type to update _M_size members after a merge.
This implements LWG 2503, which allows ^ and $ to match line terminator
characters, rather than only matching the beginning and end of the
entire input. The multiline option is only valid for ECMAScript, but
for other grammars we ignore it rather than throwing an exception.
This is related to PR libstdc++/102480, which incorrectly said that
ECMAscript should match the beginning of a line when match_prev_avail
is used. I think that's only supposed to happen when multiline is used.
The new regex_constants::multiline and basic_regex::multiline constants
are not defined for strict -std=c++11 and -std=c++14 modes, but
regex_constants::__multiline is always defined, so that the
implementation can use it internally.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
* include/bits/regex.h (basic_regex::multiline): Define constant
for C++17.
* include/bits/regex_constants.h (regex_constants::multiline):
Define constant for C++17.
(regex_constants::__multiline): Define duplicate constant for
internal use in C++11 and C++14.
* include/bits/regex_executor.h (_Executor::_M_match_multiline()):
New member function.
(_Executor::_M_is_line_terminator(_CharT)): New member function.
(_Executor::_M_at_begin(), _Executor::_M_at_end()): Use new
member functions to support multiline matches.
* testsuite/28_regex/algorithms/regex_match/multiline.cc: New test.
The standard says that it is invalid for more than one grammar element
to be set in a value of type regex_constants::syntax_option_type. This
adds a check in the regex compiler andthrows an exception if an invalid
value is used.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
* include/bits/regex_compiler.h (_Compiler::_S_validate): New
function.
* include/bits/regex_compiler.tcc (_Compiler::_Compiler): Use
_S_validate to check flags.
* include/bits/regex_error.h (_S_grammar): New error code for
internal use.
* testsuite/28_regex/basic_regex/ctors/grammar.cc: New test.
When the input sequence contains a _CharT(0) character, the strchr call
in _Scanner<_CharT>::_M_scan_normal() will search for '\0' and so return
a pointer to the terminating null at the end of the string. This makes
the scanner think it's found a special character. Because it doesn't
match any of the actual special characters, we fall off the end of the
function (or assert in debug mode).
We should check for a null character explicitly and either treat it as
an ordinary character (for the ECMAScript grammar) or an error (for all
others). I'm not 100% sure that's right, but it seems consistent with
the POSIX RE rules where a '\0' means the end of the regex pattern or
the end of the sequence being matched.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
PR libstdc++/84110
* include/bits/regex_error.h (regex_constants::_S_null): New
error code for internal use.
* include/bits/regex_scanner.tcc (_Scanner::_M_scan_normal()):
Check for null character.
* testsuite/28_regex/basic_regex/84110.cc: New test.
Introduce a new _M_compile function which does the common work needed by
all constructors and assignment. Call that directly to avoid multiple
levels of constructor delegation or calls to basic_regex::assign
overloads.
For assignment, there is no need to construct a std::basic_string if we
already have a contiguous sequence of the correct character type, and no
need to construct a temporary basic_regex when assigning from an
existing basic_regex.
Also define the copy and move assignment operators as defaulted, which
does the right thing without constructing a temporary and swapping it.
Copying or moving the shared_ptr member cannot fail, so they can be
noexcept. The assign(const basic_regex&) and assign(basic_regex&&)
member can then be defined in terms of copy or move assignment.
The new _M_compile function takes pointer arguments, so the caller has
to convert arbitrary iterator ranges into a contiguous sequence of
characters. With that simplification, the __compile_nfa helpers are not
needed and can be removed.
This also fixes a bug where construction from a contiguous sequence with
the wrong character type would fail to compile, rather than converting
the elements to the regex character type.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
* include/bits/regex.h (__detail::__is_contiguous_iter): Move
here from <bits/regex_compiler.h>.
(basic_regex::_M_compile): New function to compile an NFA from
a regular expression string.
(basic_regex::basic_regex): Use _M_compile instead of delegating
to other constructors.
(basic_regex::operator=(const basic_regex&)): Define as
defaulted.
(basic_regex::operator=(initializer_list<C>)): Use _M_compile.
(basic_regex::assign(const basic_regex&)): Use copy assignment.
(basic_regex::assign(basic_regex&&)): Use move assignment.
(basic_regex::assign(const C*, flag_type)): Use _M_compile
instead of constructing a temporary string.
(basic_regex::assign(const C*, size_t, flag_type)): Likewise.
(basic_regex::assign(const basic_string<C,T,A>&, flag_type)):
Use _M_compile instead of constructing a temporary basic_regex.
(basic_regex::assign(InputIter, InputIter, flag_type)): Avoid
constructing a temporary string for contiguous iterators of the
right value type.
* include/bits/regex_compiler.h (__is_contiguous_iter): Move to
<bits/regex.h>.
(__enable_if_contiguous_iter, __disable_if_contiguous_iter)
(__compile_nfa): Remove.
* testsuite/28_regex/basic_regex/assign/exception_safety.cc: New
test.
* testsuite/28_regex/basic_regex/ctors/char/other.cc: New test.
This fixes a logic error in the futex-based timed wait.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
* include/bits/atomic_timed_wait.h (__platform_wait_until_impl):
Return false for ETIMEDOUT and true otherwise.
There is no benefit to using _SizeT instead of size_t, and IterT tells
you less about the type than const _CharT*. This removes some unhelpful
typedefs.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
* include/bits/regex_automaton.h (_NFA_base::_SizeT): Remove.
* include/bits/regex_compiler.h (_Compiler::_IterT): Remove.
* include/bits/regex_compiler.tcc: Likewise.
* include/bits/regex_scanner.h (_Scanner::_IterT): Remove.
* include/bits/regex_scanner.tcc: Likewise.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
* include/bits/regex_compiler.tcc: Add line break in empty while
statement.
* include/bits/regex_executor.tcc: Avoid unused parameter
warning.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
* include/bits/atomic_wait.h (_GLIBCXX_HAVE_PLATFORM_WAIT):
Define before first attempt to check it.
This adds some additional checks the the C++98-style concept checks for
iterators, and removes some bogus checks for mutable iterators. Instead
of requiring that the result of dereferencing a mutable iterator is
assignable (which is a property of the value type, not required for the
iterator) check that the reference type is a non-const reference to the
value type.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
* include/bits/boost_concept_check.h (_ForwardIteratorConcept)
(_BidirectionalIteratorConcept, _RandomAccessIteratorConcept):
Check result types of iterator operations.
(_Mutable_ForwardIteratorConcept): Check that iterator's
reference type is a reference to its value type.
(_Mutable_BidirectionalIteratorConcept): Do not require the
value type to be assignable.
(_Mutable_RandomAccessIteratorConcept): Likewise.
* testsuite/24_iterators/operations/prev_neg.cc: Adjust dg-error
line number.
The _OutputIteratorConcept should be checked using the correct value
category. The std::move_backward and std::copy_backward algorithms
should use _OutputIteratorConcept instead of _ConvertibleConcept.
In order to use the correct value category, the concept should use a
function that returns _ValueT instead of using an lvalue data member.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
* include/bits/boost_concept_check.h (_OutputIteratorConcept):
Use a function to preserve value category of the type.
* include/bits/stl_algobase.h (copy, move, fill_n): Use a
reference as the second argument for _OutputIteratorConcept.
(copy_backward, move_backward): Use _OutputIteratorConcept
instead of _ConvertibleConcept.
This allows std::__to_address to be used with __normal_iterator in
C++11/14/17 modes. Without the partial specialization the deduced
pointer_traits::element_type is incorrect, and so the return type of
__to_address is wrong.
A similar partial specialization is probably needed for
__gnu_debug::_Safe_iterator.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
* include/bits/stl_iterator.h (pointer_traits): Define partial
specialization for __normal_iterator.
* testsuite/24_iterators/normal_iterator/to_address.cc: New test.
The previous message told you something was wrong, but not why it
happened or why it's bad. This changes it to explain that the function
is being misused.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
* include/bits/move.h (forward(remove_reference_t<T>&&)):
Improve text of static_assert.
* testsuite/20_util/forward/c_neg.cc: Adjust dg-error.
* testsuite/20_util/forward/f_neg.cc: Likewise.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
PR libstdc++/102499
* include/bits/fs_path.h (path::begin, path::end): Add noexcept
to declarations, to match definitions.
These functions are constexpr, which means they are implicitly inline.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
* include/bits/range_access.h (cbegin, cend): Remove redundant
'inline' specifier.
All path::iterator operations are non-throwing.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
* include/bits/fs_path.h (path::iterator): Add noexcept to all
member functions and friend functions.
(distance): Add noexcept.
(advance): Add noexcept and inline.
* include/experimental/bits/fs_path.h (path::iterator):
Add noexcept to all member functions.
Also rename the test so it actually runs.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
PR libstdc++/102270
* include/std/tuple (_Tuple_impl): Add constexpr to constructor
missed in previous patch.
* testsuite/20_util/tuple/cons/102270.C: Moved to...
* testsuite/20_util/tuple/cons/102270.cc: ...here.
* testsuite/util/testsuite_allocator.h (SimpleAllocator): Add
constexpr to constructor so it can be used for C++20 tests.
This was just a copy and paste error.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
* include/bits/fs_path.h (advance): Remove non-deducible
template parameter.
When the values is guaranteed to fit in the SSO buffer we know the
string won't allocate, so the function can be noexcept. For 32-bit
integers, we know they need no more than 9 bytes (or 10 with a minus
sign) and the SSO buffer is 15 bytes.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
* include/bits/basic_string.h [_GLIBCXX_USE_CXX11_ABI]
(to_string): Add noexcept if the type width is 32 bits or less.
The last missing piece of the C++17 standard library is the hardware
intereference size constants. Much of the delay in implementing these has
been due to uncertainty about what the right values are, and even whether
there is a single constant value that is suitable; the destructive
interference size is intended to be used in structure layout, so program
ABIs will depend on it.
In principle, both of these values should be the same as the target's L1
cache line size. When compiling for a generic target that is intended to
support a range of target CPUs with different cache line sizes, the
constructive size should probably be the minimum size, and the destructive
size the maximum, unless you are constrained by ABI compatibility with
previous code.
From discussion on gcc-patches, I've come to the conclusion that the
solution to the difficulty of choosing stable values is to give up on it,
and instead encourage only uses where ABI stability is unimportant: in
particular, uses where the ABI is shared at most between translation units
built at the same time with the same flags.
To that end, I've added a warning for any use of the constant value of
std::hardware_destructive_interference_size in a header or module export.
Appropriate uses within a project can disable the warning.
A previous iteration of this patch included an -finterference-tune flag to
make the value vary with -mtune; this iteration makes that the default
behavior, which should be appropriate for all reasonable uses of the
variable. The previous default of "stable-ish" seems to me likely to have
been more of an attractive nuisance; since we can't promise actual
stability, we should instead make proper uses more convenient.
JF Bastien's implementation proposal is summarized at
https://github.com/itanium-cxx-abi/cxx-abi/issues/74
I implement this by adding new --params for the two sizes. Targets can
override these values in targetm.target_option.override() to support a range
of values for the generic target; otherwise, both will default to the L1
cache line size.
64 bytes still seems correct for all x86.
I'm not sure why he proposed 64/64 for generic 32-bit ARM, since the Cortex
A9 has a 32-byte cache line, so I'd think 32/64 would make more sense.
He proposed 64/128 for generic AArch64, but since the A64FX now has a 256B
cache line, I've changed that to 64/256.
Other arch maintainers are invited to set ranges for their generic targets
if that seems better than using the default cache line size for both values.
With the above choice to reject stability as a goal, getting these values
"right" is now just a matter of what we want the default optimization to be,
and we can feel free to adjust them as CPUs with different cache lines
become more and less common.
gcc/ChangeLog:
* params.opt: Add destructive-interference-size and
constructive-interference-size.
* doc/invoke.texi: Document them.
* config/aarch64/aarch64.c (aarch64_override_options_internal):
Set them.
* config/arm/arm.c (arm_option_override): Set them.
* config/i386/i386-options.c (ix86_option_override_internal):
Set them.
gcc/c-family/ChangeLog:
* c.opt: Add -Winterference-size.
* c-cppbuiltin.c (cpp_atomic_builtins): Add __GCC_DESTRUCTIVE_SIZE
and __GCC_CONSTRUCTIVE_SIZE.
gcc/cp/ChangeLog:
* constexpr.c (maybe_warn_about_constant_value):
Complain about std::hardware_destructive_interference_size.
(cxx_eval_constant_expression): Call it.
* decl.c (cxx_init_decl_processing): Check
--param *-interference-size values.
libstdc++-v3/ChangeLog:
* include/std/version: Define __cpp_lib_hardware_interference_size.
* libsupc++/new: Define hardware interference size variables.
gcc/testsuite/ChangeLog:
* g++.dg/warn/Winterference.H: New file.
* g++.dg/warn/Winterference.C: New test.
* g++.target/aarch64/interference.C: New test.
* g++.target/arm/interference.C: New test.
* g++.target/i386/interference.C: New test.
For some reason r170217 didn't add compare_exchange_weak to the
__atomic_base<T*> partial specialization, and so weak compare exchange
operations on pointers use compare_exchange_strong instead.
This adds __atomic_base<T*>::compare_exchange_weak and then uses it in
std::atomic<T*>::compare_exchange_weak.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
* include/bits/atomic_base.h (__atomic_base<P*>::compare_exchange_weak):
Add new functions.
* include/std/atomic (atomic<T*>::compare_exchange_weak): Use
it.
P0418R2 removed some preconditions from std::atomic::compare_exchange_*
but we still enforce them via __glibcxx_assert. This removes those
assertions.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
PR c++/102177
* include/bits/atomic_base.h (__is_valid_cmpexch_failure_order):
New function to check if a memory order is valid for the failure
case of compare exchange operations.
(__atomic_base<I>::compare_exchange_weak): Simplify assertions
by using __is_valid_cmpexch_failure_order.
(__atomic_base<I>::compare_exchange_strong): Likewise.
(__atomic_base<P*>::compare_exchange_weak): Likewise.
(__atomic_base<P*>::compare_exchange_strong): Likewise.
(__atomic_impl::compare_exchange_weak): Add assertion.
(__atomic_impl::compare_exchange_strong): Likewise.
* include/std/atomic (atomic::compare_exchange_weak): Likewise.
(atomic::compare_exchange_strong): Likewise.
We already supported this feature as std::__invoke<R>, for internal use.
This just adds a public version of it to <functional>.
Internal uses should continue to include <bits/invoke.h> and use
std::__invoke<R> so that they don't need to include all of <functional>.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
* include/std/functional (invoke_r): Define.
* include/std/version (__cpp_lib_invoke_r): Define.
* testsuite/20_util/function_objects/invoke/version.cc: Check
for __cpp_lib_invoke_r as well as __cpp_lib_invoke.
* testsuite/20_util/function_objects/invoke/4.cc: New test.
This adds a missing return statement to the non-futex wait-until
operation.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
PR libstdc++/102074
* include/bits/atomic_timed_wait.h (__timed_waiter_pool)
[!_GLIBCXX_HAVE_PLATFORM_TIMED_WAIT]: Add missing return.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
* include/experimental/internet (__make_resolver_error_code):
Handle EAI_SYSTEM errors.
(basic_resolver_results): Use __make_resolver_error_code. Use
Glibc NI_MAXHOST and NI_MAXSERV values for buffer sizes.
