To use the FILE data structure, LLVM-libc must be in fullbuild mode
since it expects its own implementation. This means that (f)printf can't
be used without fullbuild, but s(n)printf only uses strings. This patch
adjusts the CMake to allow for this.
Reviewed By: sivachandra, lntue
Differential Revision: https://reviews.llvm.org/D131913
Implement tanf function correctly rounded for all rounding modes.
We use the range reduction that is shared with `sinf`, `cosf`, and `sincosf`:
```
k = round(x * 32/pi) and y = x * (32/pi) - k.
```
Then we use the tangent of sum formula:
```
tan(x) = tan((k + y)* pi/32) = tan((k mod 32) * pi / 32 + y * pi/32)
= (tan((k mod 32) * pi/32) + tan(y * pi/32)) / (1 - tan((k mod 32) * pi/32) * tan(y * pi/32))
```
We need to make a further reduction when `k mod 32 >= 16` due to the pole at `pi/2` of `tan(x)` function:
```
if (k mod 32 >= 16): k = k - 31, y = y - 1.0
```
And to compute the final result, we store `tan(k * pi/32)` for `k = -15..15` in a table of 32 double values,
and evaluate `tan(y * pi/32)` with a degree-11 minimax odd polynomial generated by Sollya with:
```
> P = fpminimax(tan(y * pi/32)/y, [|0, 2, 4, 6, 8, 10|], [|D...|], [0, 1.5]);
```
Performance benchmark using `perf` tool from the CORE-MATH project on Ryzen 1700:
```
$ CORE_MATH_PERF_MODE="rdtsc" ./perf.sh tanf
CORE-MATH reciprocal throughput : 18.586
System LIBC reciprocal throughput : 50.068
LIBC reciprocal throughput : 33.823
LIBC reciprocal throughput : 25.161 (with `-msse4.2` flag)
LIBC reciprocal throughput : 19.157 (with `-mfma` flag)
$ CORE_MATH_PERF_MODE="rdtsc" ./perf.sh tanf --latency
GNU libc version: 2.31
GNU libc release: stable
CORE-MATH latency : 55.630
System LIBC latency : 106.264
LIBC latency : 96.060
LIBC latency : 90.727 (with `-msse4.2` flag)
LIBC latency : 82.361 (with `-mfma` flag)
```
Reviewed By: orex
Differential Revision: https://reviews.llvm.org/D131715
Specifically, POSIX functions pthread_key_create, pthread_key_delete,
pthread_setspecific and pthread_getspecific have been added. The C
standard equivalents tss_create, tss_delete, tss_set and tss_get have
also been added.
Reviewed By: lntue, michaelrj
Differential Revision: https://reviews.llvm.org/D131647
With correctly rounded implementations, these functions will be tested for all
rounding modes. Since fegetround and fesetround are not implemented for arm32,
these tests will fail in all non-default rounding modes. We will re-enable
these entrypoints and tests once fegetround and fesetround are implemented for
arm32.
This patch adds all the string and stdlib entrypoints, as well as a few
math entrypoints to the arm32 build.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D129821
This is a implementation of find remainder fmod function from standard libm.
The underline algorithm is developed by myself, but probably it was first
invented before.
Some features of the implementation:
1. The code is written on more-or-less modern C++.
2. One general implementation for both float and double precision numbers.
3. Spitted platform/architecture dependent and independent code and tests.
4. Tests covers 100% of the code for both float and double numbers. Tests cases with NaN/Inf etc is copied from glibc.
5. The new implementation in general 2-4 times faster for “regular” x,y values. It can be 20 times faster for x/y huge value, but can also be 2 times slower for double denormalized range (according to perf tests provided).
6. Two different implementation of division loop are provided. In some platforms division can be very time consuming operation. Depend on platform it can be 3-10 times slower than multiplication.
Performance tests:
The test is based on core-math project (https://gitlab.inria.fr/core-math/core-math). By Tue Ly suggestion I took hypot function and use it as template for fmod. Preserving all test cases.
`./check.sh <--special|--worst> fmodf` passed.
`CORE_MATH_PERF_MODE=rdtsc ./perf.sh fmodf` results are
```
GNU libc version: 2.35
GNU libc release: stable
21.166 <-- FPU
51.031 <-- current glibc
37.659 <-- this fmod version.
```
The TLS loader test has been enabled for aarch64.
Handling of PT_TLS' filesz and memsz for x86_64 has also been fixed.
Reviewed By: jeffbailey
Differential Revision: https://reviews.llvm.org/D128032
This patch adds the entrypoint for printf. With this, building a
"hello world" program with just LLVM-libc is possible.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D126831
Tests for pthread_detach and thrd_detach have not been added. Instead, a
test for the underlying implementation has been added as it makes use of
an internal wait method to synchronize with detached threads.
Reviewed By: lntue, michaelrj
Differential Revision: https://reviews.llvm.org/D127479
Previously all FILE objects were fully buffered, this patch adds line
buffering and unbuffered output, as well as applying them to stdout and
stderr.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D126829
They do not yet support all the feature/attributes in pthread_attr_t.
Future changes will add such support.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D126718
This patch adds the file_writer header, which just provides a wrapper
for File->write, as well as fprintf to use it. There are no unit tests
for file_writer since it's too simple to need them, but fprintf does
have a simple test of writing to a file.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D125939
They are added as entrypoint object targets. The header-gen
infrastructure has been extended to enable handling standard required
global objects. The libc-api-test has also been extended to verify the
global object declarations.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D126329
Simple implementations of the functions pthread_mutex_init,
pthread_mutex_destroy, pthread_mutex_lock and pthread_mutex_unlock have
have also been added. Future patches will extend these functions to add
features required by the POSIX specification.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D126235
After adding sprintf, snprintf is simple. The functions are very
similar. The tests only cover the behavior of the max length since the
sprintf tests should cover the other behavior.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D125826
This adds the sprintf entrypoint, as well as unit tests. Currently
sprintf only supports %%, %s, and %c, but the other conversions are on
the way.
Reviewed By: sivachandra, lntue
Differential Revision: https://reviews.llvm.org/D125573
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
All existing loader tests are switched to an integration test added with
the new rule. Also, the getenv test is now enabled as an integration test.
All loader tests have been moved to test/integration. Also, the simple
checker library for the previous loader tests has been moved to a
separate directory of its own.
A follow up change will perform more cleanup of the loader CMake rules
to eliminate now redundent options.
Reviewed By: lntue, michaelrj
Differential Revision: https://reviews.llvm.org/D122266
The loader TLS test for x86_64, which now passes, has been enabled.
A future change should enable the test for aarch64 as well.
Reviewed By: jeffbailey
Differential Revision: https://reviews.llvm.org/D121091
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
New methods to the Atomic class have been added as required. Futex
related types have been consolidated at a common place.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D120705
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
Siva Chandra Reddy