`MinSequenceContainer::size` can be narrowing on 64-bit platforms, and
MSVC complains about such implicit conversion. This PR changes the
implicit conversion to explicit `static_cast`.
`min_allocator::allocate` and `min_allocator::deallocate` have
`ptrdiff_t` as the parameter type, which seems weird, because the
underlying `std::allocator`'s member functions take `size_t`. It seems
better to use `size_t` consistently.
This patch does not significantly change how the sequence container
benchmarks are done, but it adopts the same style as the associative
container benchmarks.
This commit does adjust how we were benchmarking push_back, where we
never really measured the overhead of the slow path of push_back (when
we need to reallocate).
It turns out that the new implementation takes significantly more stack
memory for some reason.
This reverts commit 2696e4fb9567d23ce065a067e7f4909b310daf50.
This patch implements generic associative container benchmarks for
containers with unique keys. In doing so, it replaces the existing
std::map benchmarks which were based on the cartesian product
infrastructure and were too slow to execute.
These new benchmarks aim to strike a balance between exhaustive coverage
of all operations in the most interesting case, while executing fairly
rapidly (~40s on my machine).
This bumps the requirement for the map benchmarks from C++17 to C++20
because the common header that provides associative container benchmarks
requires support for C++20 concepts.
Having them defined ouf-of-line results in a significant amount of
boilerplate without improving readability, since they're just one or two
lines long anyways.
As a drive-by, add comments between the declarations to make them easier
to distinguish.
Implements parts of:
- P0355 Extending <chrono> to Calendars and Time Zones
- P1361 Integration of chrono with text formatting
- LWG3359 <chrono> leap second support should allow for negative leap
seconds
The capacity is now passed correctly and a test for this path is added.
Since we changed the implementation of `reserve(size_type)` to only ever
extend,
it doesn't make a ton of sense anymore to have `__shrink_or_extend`,
since the code
paths of `reserve` and `shrink_to_fit` are now almost completely
separate.
This patch splits up `__shrink_or_extend` so that the individual parts
are in `reserve`
and `shrink_to_fit` depending on where they are needed.
This reverts commit 59f57be94f38758616b1339b293b43af845571af.
This PR slightly simplifies the implementation of `vector<bool>::max_size`
and adds extensive tests for the `max_size()` function for both `vector<bool>`
and `vector<T>`. The main purposes of the new tests include:
- Verify correctness of `max_size()` under various `size_type` and
`difference_type` definitions: check that `max_size()` works properly
with allocators that have custom `size_type` and `difference_type`. This
is particularly useful for `vector<bool>`, as different `size_type` lead
to different `__storage_type` of different word lengths, resulting in
varying `max_size()` values for `vector<bool>`. Additionally, different
`difference_type` also sets different upper limit of `max_size()` for
both `vector<bool>` and `std::vector`. These tests were previously
missing.
- Eliminate incorrect implementations: Special tests are added to identify and
reject incorrect implementations of `vector<bool>::max_size` that unconditionally
return `std::min<size_type>(size-max, __internal_cap_to_external(allocator-max-size))`.
This can cause overflow in the `__internal_cap_to_external()` call and lead
to incorrect results. The new tests ensure that such incorrect
implementations are identified.
The __is_trivially_relocatable builtin has semantics that do not
correspond to any current or future notion of trivial relocation.
Furthermore, it currently leads to incorrect optimizations for some
types on supported compilers:
- Clang on Windows where types with non-trivial destructors get
incorrectly optimized
- AppleClang where types with non-trivial move constructors get
incorrectly optimized
Until there is an agreed upon and bugfree implementation of what it
means to be trivially relocatable, it is safer to simply use trivially
copyable instead. This doesn't leave a lot of types behind and is
definitely correct.
This PR addresses an undefined behavior that arises when using the
`std::fill` and `std::fill_n` algorithms, as well as their ranges
counterparts `ranges::fill` and `ranges::fill_n`, with `vector<bool, Alloc>`
that utilizes a custom-sized allocator with small integral types.
There's no reason not to, and it's easy enough to do using enable_if. As
a drive-by change, also add a missing _LIBCPP_NO_CFI attribute on
__add_alignment_assumption.
The previous tested TZDB did not contain %z for the rule letters. The
usage of %z in TZDB 2024b revealed a bug in the implementation. The
patch fixes it and has been locally tested with TZDB 2024b.
Fixes#108957
Using `if constexpr` in `__constexpr_memmove` makes the instantiation
three times faster for the same type, since it avoids a bunch of class
instantiations and SFINAE for constexpr support that's never actually
used. Given that `__constexpr_memmove` is used quite a bit through
`std::copy` and is instantiated multiple times when just including
`<__string/char_traits.h>` this can provide a nice compile time speedup
for a very simple change.
Rewrite the sequence container benchmarks to only rely on the actual
operations specified in SequenceContainer requirements and add
benchmarks for std::list, which is also considered a sequence container.
One of the major goals of this refactoring is also to make these
container benchmarks run faster so that they can be run more frequently.
The existing benchmarks have the significant problem that they take so
long to run that they must basically be run overnight. This patch
reduces the size of inputs such that the rewritten benchmarks each take
at most a minute to run.
This patch doesn't touch the string benchmarks, which were not using the
generic container benchmark functions previously.
As a follow-up to #121013 (which focused on `std::ranges::copy`), this
PR optimizes the performance of `std::ranges::copy_backward` for
`vector<bool>::iterator`, addressing a subtask outlined in issue #64038.
The optimizations yield performance improvements of up to 2000x for
aligned copies and 60x for unaligned copies.
This refactors the standard stream implementation in multiple ways:
- The streams are now `stream_data` structs, which contain all the data
required for a stream
- The windows mangling is generated via a macro instead of having magic
strings for the different streams. (i.e. it's now only partially magic)
This patch simplifies the implementation of `__construct_at_end` in
`vector<bool>`, which currently contains duplicate initialization logic
across its two overloads.
These symbols are never referenced directly outside the dylib, so we can
make them hidden instead. They are still in the dylib since can be
referenced through the `memory_resource*`, but dynamic linkers don't
have to do any work to deduplicate them.
This patch adds the following pieces to the locale base API:
- __setlocale (for std::setlocale)
- __lconv_t (for std::lconv)
- _LIBCPP_FOO_MASK and _LIBCPP_LC_ALL
This should be sufficient to implement all of the platform-agnostic
localization support in libc++ without relying directly on any public
API names from the C library. This makes it possible to port libc++ to
platforms that don't provide the usual locale APIs.
This changes the __output_buffer to a new structure. This improves the
performace of std::format, std::format_to, std::format_to_n, and
std::formatted_size.
The old and new implementation of `_And` are very close in terms of
performance according to my testing, but the new implementation can also
be used to implement `conjunction`, which make that ~50% faster.
The commit 24e70e3930724ce499ad05d669bfbc4423c542e0 changed internal
macros which were used in 0cd794d4860e376698bb4da24bcdf8cbf331835c.
This caused build failures on platforms without TZDB support
