Note that the underlying flush implementation does not yet fully implement
the POSIX standard. It is complete with respect to the C standard
however. A future change will add the POSIX behavior. It should not affect
the implementation of the fflush function however as the POSIX behavior
will be added in a lower layer.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D124073
POSIX locking and unlocking functions flockfile and funlockfile have
also been added. The locking is not recursive yet. A future patch will
make the underlying lock a recursive lock.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D123986
Not all attributes have been added to phtread_attr_t in this patch. They
will be added gradually in future patches.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D123423
A simple implementation of the getters and setters has been added. More
logic can be added to them in future as required.
Reviewed By: michaelrj
Differential Revision: https://reviews.llvm.org/D122969
This patch adds aligned_alloc as an entrypoint. Previously it was being
included implicitly.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D122362
With modern architectures having a thread pointer and language supporting
thread locals, there is no reason to use a function intermediary to access
the thread local errno value.
The entrypoint corresponding to errno has been replaced with an object
library as there is no formal entrypoint for errno anymore.
Reviewed By: jeffbailey, michaelrj
Differential Revision: https://reviews.llvm.org/D120920
Often atexit is implemented using __cxa_atexit. I have not implemented __cxa_atexit here because it potentially requires more discussion. It is unique for llvm-libc (I think) that it is an exported symbol that wouldn’t be defined in any spec file because it doesn’t have a header. Implementing it will be trivial given what is here already, but I figured it would be more contentious so it can be implemented later.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D119512
Add support for getenv as defined by the Open Group's "System Interface &
Header" in https://pubs.opengroup.org/onlinepubs/7908799/xsh/getenv.html
getenv requires a standard way of accessing the environment,
so a pointer to the environment is added to the startup in crt1.
Consquently, this function is not usable on top of other libcs.
Added starts_with method to StringView. getenv function uses it.
Co-authored-by: Jeff Bailey <jeffbailey@google.com>
Reviewed By: sivachandra, rtenneti
Differential Revision: https://reviews.llvm.org/D119403
They are implemented as simple syscall wrappers. The file creation
macros have been put in a header file as a temporary solution until we
have a cleaner approach to listing platform relevant macros.
Reviewed By: abrachet
Differential Revision: https://reviews.llvm.org/D118396
The type names in the spec are just sugar used by the header generator to
generate the function prototype. Giving the VarArgType a name of "..."
allows the header generator to treat and generate the "type name" for var
arg parameters similar to how it does for any other type.
Based on RLIBM implementation similar to logf and log2f. Most of the exceptional inputs are the exact powers of 10.
Reviewed By: sivachandra, zimmermann6, santoshn, jpl169
Differential Revision: https://reviews.llvm.org/D118093
Due to the differences between the types of long double, this function
is effectively three functions in one. This patch adds basic support for
the types of long double, although it's just using the fast path and the
fallback for the moment. I still need to implement a version of
Eisel-Lemire for performance, but the existing algorithms should be
correct.
Reviewed By: sivachandra, lntue
Differential Revision: https://reviews.llvm.org/D113710
Adds an implementation for stpcpy and stpncpy, which are posix extension
functions.
Reviewed By: sivachandra, lntue
Differential Revision: https://reviews.llvm.org/D111913
malloc, calloc, realloc, and free are all functions that other libc
functions depend on, but are pulled from external sources, instead of
having an internal implementation. This patch adds a way to include
functions like that as entrypoints in the list of external entrypoints,
and includes the malloc functions using this new path.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D112104
Add an implementation for memccpy and mempcpy. These functions are
posix extensions for the moment.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D111762
This patch adds a skeleton as a preparatory step for the next patch which
adds the actual implementations of the condition variable functions.
Reviewed By: michaelrj
Differential Revision: https://reviews.llvm.org/D108947
Add inttypes.h to llvm libc. As its first functions strtoimax and
strtoumax are included.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D108736
This is based on the work done to add strtoll and the other strto
functions. The atoi functions also were added to stdc and
entrypoints.txt.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D108330
Updates the internal string conversion function so that it
uses the new Limits.h added in a previous commit for max and min values,
and has a templated type. This makes implementing the other strto*
functions very simple.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D107999
This change adds the stroll function, but most of the implementation is
in the new file str_conv_utils.h since many of the other integer
conversion functions are implemented through what are effectively calls
to strtoll.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D107792
Use expm1f(x) = exp(x) - 1 for |x| > ln(2).
For |x| <= ln(2), divide it into 3 subintervals: [-ln2, -1/8], [-1/8, 1/8], [1/8, ln2]
and use a degree-6 polynomial approximation generated by Sollya's fpminmax for each interval.
Errors < 1.5 ULPs when we use fma to evaluate the polynomials.
Differential Revision: https://reviews.llvm.org/D101134
The implementations use the x86_64 FPU instructions. These instructions
are extremely slow compared to a polynomial based software
implementation. Also, their accuracy falls drastically once the input
goes beyond 2PI. To improve both the speed and accuracy, we will be
taking the following approach going forward:
1. As a follow up to this CL, we will implement a range reduction algorithm
which will expand the accuracy to the entire double precision range.
2. After that, we will replace the HW instructions with a polynomial
implementation to improve the run time.
After step 2, the implementations will be accurate, performant and target
architecture independent.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D102384
[libc] Introduce asctime, asctime_r to LLVM libc
asctime and asctime_r share the same common code. They call asctime_internal
a static inline function.
asctime uses snprintf to return the string representation in a buffer.
It uses the following format (26 characters is the buffer size) as per
7.27.3.1 section in http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2478.pdf.
The buf parameter for asctime_r shall point to a buffer of at least 26 bytes.
snprintf(buf, 26, "%.3s %.3s%3d %.2d:%.2d:%.2d %d\n",...)
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D99686
gmtime and gmtime_r share the same common code. They call gmtime_internal
a static inline function. Thus added only validation tests for gmtime_r.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D99046
This change doesn't handle TIMEZONE, tm_isdst and leap seconds.
Moved shared code between mktime and gmtime into time_utils.cpp.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D98467
Namely, implementations of fegetexceptfflag, fesetexceptflag,
fegetenv, fesetenv, feholdexcept and feupdateenv have been added.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D96935
A differential fuzzer for these functions has also been added.
Along the way, a small correction has been done to the normal/subnormal
limits of x86 long double values.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D94109
The implementation is exactly the same as rint* as even rint does not
raise any floating point exceptions currently. [Note that the standards
do not specify that floating point exceptions must be raised - they
leave it up to the implementation to choose to raise FE_INEXACT when
rounding non-integral values.]
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D94112
Siva Chandra Reddy