The current implementation of binomial_distribution is not guaranteed to
converge for certain extreme configurations of the engine and distribution.
This is due to a mistake in the implementation of the algorithm from the
given reference paper. The algorithm in the paper is guaranteed to
terminate but has redundant statements. The current implementation
simplified away the redundancy into a while loop, but it excludes the
return condition of the case where a good sample cannot be returned for
the particular sample being used from the uniform distribution, which is
what causes the infinite loop. This change guarantees termination by
recognizing that a good sample cannot be returned and returning 0 after
breaking the loop. This is also in contrast to the paper because the
return value as specified in the paper violates basic checks in at least
a subset of the extreme cases where the current implementation fails to
terminate. This default return value of 0 is satisfactory for the
extreme case known so far.
Since this is only meant to affect extreme cases where the algorithm
does not terminate anyways, the behavior is expected to remain exactly
the same for all non-extreme cases that have been terminating so far.
Fixes https://llvm.org/PR44847
Differential Revision: https://reviews.llvm.org/D74997
Summary:
The former are like:
libcxx/include/typeinfo:322:11: warning: definition of implicit copy constructor for 'bad_cast' is deprecated because it has a user-declared destructor [-Wdeprecated-copy-dtor]
virtual ~bad_cast() _NOEXCEPT;
^
libcxx/include/typeinfo:344:11: note: in implicit copy constructor for 'std::bad_cast' first required here
throw bad_cast();
^
Fix these by adding an explicitly defaulted copy constructor.
The latter are like:
libcxx/include/codecvt:105:37: warning: dynamic exception specifications are deprecated [-Wdeprecated-dynamic-exception-spec]
virtual int do_encoding() const throw();
^~~~~~~
Fix these by using the _NOEXCEPT macro instead.
Reviewers: EricWF, mclow.lists, ldionne, #libc
Reviewed By: EricWF, #libc
Subscribers: dexonsmith, libcxx-commits
Tags: #libc
Differential Revision: https://reviews.llvm.org/D76150
Summary:
Android's libc uses new/delete internally and these are counted, so
the counter needs to be reset to zero at the start of the test.
Reviewers: EricWF, mclow.lists, #libc, ldionne
Reviewed By: #libc, ldionne
Subscribers: dexonsmith, libcxx-commits
Tags: #libc
Differential Revision: https://reviews.llvm.org/D76091
The benchmarks are intended to be build with C++17 but the
CMAKE_CXX_STANDARD in the LLVM forces the build to use C++14 by default.
This fixes the issue by setting the CXX_STANDARD property of the benchmark
targets.
The CMake documentation is not clear whether this will use the C++1z
fallback for older compilers. So this may break the benchmarks if somebody
uses the benchmarks with pre C++17 compilers with the C++1z fallback.
Differential Revision: https://reviews.llvm.org/D75955
Summary: The return type modification has already been implemented in rL364840 and rL365290.
Reviewers: ldionne, mclow.lists, EricWF, #libc!
Reviewed By: ldionne
Subscribers: christof, dexonsmith, libcxx-commits
Tags: #libc
Differential Revision: https://reviews.llvm.org/D70275
Summary:
This is NFC. We only add additional information to the log.
Reviewers: EricWF, ldionne, mclow.lists
Reviewed By: ldionne
Subscribers: kristof.beyls, dexonsmith, danielkiss, mgorny, ldionne, libcxx-commits
Tags: #libc
Differential Revision: https://reviews.llvm.org/D75991
Due to Clang bug http://llvm.org/PR45151, deprecated attributes are not
picked up on partial specializations. This patch instead applies it to
the first declaration of std::function itself.
Summary:
This is a recommit of https://reviews.llvm.org/D73223 where the added function accidentally ended up inside an idef block.
This change splits the copy constructor up inlining short initialization, and explicitly outlining long initialization into __init_copy_ctor_external() which is the externally instantiated slow path.
For unstable ABI, this has the following changes:
remove basic_string(const basic_string&)
remove basic_string(const basic_string&, const Allocator&)
add __init_copy_ctor_external(const value_type*, size_type)
Quick local benchmark for Copy:
Master
```
---------------------------------------------------------------
Benchmark Time CPU Iterations
---------------------------------------------------------------
BM_StringCopy_Empty 3.50 ns 3.51 ns 199326720
BM_StringCopy_Small 3.50 ns 3.51 ns 199510016
BM_StringCopy_Large 15.7 ns 15.7 ns 45230080
BM_StringCopy_Huge 1503 ns 1503 ns 464896
```
With this change
```
---------------------------------------------------------------
Benchmark Time CPU Iterations
---------------------------------------------------------------
BM_StringCopy_Empty 1.99 ns 2.00 ns 356471808
BM_StringCopy_Small 3.29 ns 3.30 ns 203425792
BM_StringCopy_Large 13.3 ns 13.3 ns 52948992
BM_StringCopy_Huge 1472 ns 1472 ns 475136
```
Subscribers: libcxx-commits
Tags: #libc
Differential Revision: https://reviews.llvm.org/D75639
They need to appear before any member functions are ODR used, because
they change the visibility of many of these functions and otherwise
they could end up with hidden visibility in the DSO.
The goal of the test was only to check that we could access the
`this->current` member of std::reverse_iterator from a derived
class, but in doing so we incremented a null iterator, which is UB.
We always want to build the table of contents. Additionally, we also
set the flag to make the output deterministic which is already the
default for llvm-ar.
Differential Revision: https://reviews.llvm.org/D74108
Summary: This review is a mostly trivial change to use an explicit ABI flag for the unstable external template list. This follows the practice for an ABI flag per feature, and provides a spot for the rational / motivation for the flag.
Reviewers: EricWF, ldionne
Subscribers: dexonsmith, libcxx-commits
Tags: #libc
Differential Revision: https://reviews.llvm.org/D75457
I've been sitting on this change for a while and have been using
it to build the bot images, so it should be upstream.
This re-configures the docker build files to use docker-compose
more heavily. This allows for composing large images with multiple
compilers without invalidating the docker caches.
After this commit I'll quickly switch all the current buildbots
over to a new docker image, followed by another update to add new
compilers
These tests check that an operations happens within a specified
deadline, which causes flaky failures on slow machines or machines
under heavy load.
By adding the // FLAKY_TEST. tag it allows the test suite to
retry or ignore the tests
The markup wasn't quite right, and that broke compilation with availability
markup enabled. I'm disabling it until I have time to fix it properly to
get the CI mostly green again.
Summary:
This change checks for the case where people want to erase a string to the end, i.e., __n == npos, and inlines the call if so.
This also demonstrates keeping the ABI intact for V1, but inlining the erase() method for unstable.
Reviewers: EricWF, mclow.lists, ldionne
Reviewed By: EricWF, ldionne
Subscribers: smeenai, dexonsmith, christof, libcxx-commits
Tags: #libc
Differential Revision: https://reviews.llvm.org/D73743
Summary:
The definition of `__libcpp_timed_backoff_policy` and the declaration of
`__libcpp_thread_poll_with_backoff` must not be guarded by
#if !defined(_LIBCPP_HAS_THREAD_API_EXTERNAL)
because the definitions of `__libcpp_timed_backoff_policy::operator()`
and `__libcpp_thread_poll_with_backoff` aren't guarded by this macro
(and this is correct because these two functions are implemented in
terms of other libc++ functions and don't interact with the host
threading library).
Reviewers: ldionne, __simt__, EricWF, mclow.lists
Reviewed By: ldionne
Subscribers: dexonsmith, libcxx-commits
Tags: #libc
Differential Revision: https://reviews.llvm.org/D75191
Summary:
This change adds the macros _LIBCPP_COMPILER_HAS_BUILTIN_CONSTANT and _LIBCPP_BUILTIN_CONSTANT_P to detect compile time constants, and optimze the code accordingly.
A planned usage example:
The implementation of basic_string::assign() can short-cut a compile time known short string assignent into a fast and compact inlined assignment:
```
basic_string::assign(const value_type* __s) {
if (_LIBCPP_BUILTIN_CONSTANT_P(__s[0]) && length(__s) < __min_cap) {
copy(pointer(), _s, length(__s) + 1);
set_size(length(__s));
} else {
// delegate / tail call out of line implementation
}
}
```
Subscribers: christof, libcxx-commits
Tags: #libc
Differential Revision: https://reviews.llvm.org/D73732
std::shared_ptr::allocate_shared isn't in the standard. This commit removes it from libc++. It updates std::allocate_shared to use __create_with_cntrl_block.
Differential Revision: https://reviews.llvm.org/D66178
Atmn Patel