Closes#161461
- This is my first time contributing to libc's POSIX, so for reference I
used `clock_gettime` implementation for Linux. For convenience, here is
the description of `clock_settime` function
[behavior](https://www.man7.org/linux/man-pages/man3/clock_settime.3.html)
Closes#159614
**Changes:**
- Initial implementation of rsqrt for single precision float
**Some small unrelated style changes to this PR (that I missed in my
rsqrtf16 PR):**
- Added extra - to the top comments to make it look nicer in
libc/shared/math/rsqrtf16.h
- Put rsqrtf16 inside of libc/src/__support/math/CMakeLists.txt in
sorted order
- Rearanged libc_math_function rsqrtf16 in Bazel to match alphabetical
order
This PR includes only one of the fxdivi functions (rdivi). It uses a
polynomial function for initial approximation followed by 4
newton-raphson iterations to calculate the reciprocal and finally
multiplies the numerator with it to get the result.
---------
Signed-off-by: Shreeyash Pandey <shreeyash335@gmail.com>
This patch enhances the GPU support documentation page (`support.html`)
by adding a new, detailed section for `math.h`. This new section
presents the results of the GPU math conformance tests, providing
quantitative data on the accuracy of the supported higher math
functions.
This is an implementation for template functions of localtime.
Update for this pull request: Implementation as been removed from this
pull request and will be added to a new one. This is because this pull
request is getting big. This pull request will only contain template
functions in order to implement localtime.
Update: The implementation is available in
https://github.com/zimirza/llvm-project/tree/localtime_implementation.
---------
Co-authored-by: Зишан Мирза <zmirza@tutanota.de>
Co-authored-by: Zishan Mirza <zmirza@posteo.de>
This PR adds the following basic math functions for BFloat16 type along
with the tests:
- scalbnbf16
- scalblnbf16
---------
Signed-off-by: Krishna Pandey <kpandey81930@gmail.com>
This PR adds the following basic math functions for BFloat16 type along
with the tests:
- totalorderbf16
- totalordermagbf16
---------
Signed-off-by: Krishna Pandey <kpandey81930@gmail.com>
This PR adds the following basic math functions for BFloat16 type along
with the tests:
- canonicalizebf16
- iscanonicalbf16
- fdimbf16
- copysignbf16
- issignalingbf16
---------
Signed-off-by: Krishna Pandey <kpandey81930@gmail.com>
This PR adds the following basic math functions for BFloat16 type along
with the tests:
- modfbf16
- remainderbf16
- remquobf16
---------
Signed-off-by: Krishna Pandey <kpandey81930@gmail.com>
Co-authored-by: OverMighty <its.overmighty@gmail.com>
This PR adds the following basic math functions for BFloat16 type along
with the tests:
- frexpbf16
- ilobbf16
- ldexpbf16
- llogbbf16
- logbbf16
---------
Signed-off-by: Krishna Pandey <kpandey81930@gmail.com>
This PR adds the following basic math functions for BFloat16 type along
with the tests:
- nearbyintbf16
- rintbf16
- lrintbf16
- llrintbf16
- lroundbf16
- llroundbf16
---------
Signed-off-by: Krishna Pandey <kpandey81930@gmail.com>
This PR adds the following basic math functions for BFloat16 type along
with the tests:
- getpayloadbf16
- setpayloadbf16
- setpayloadsigbf16
---------
Signed-off-by: Krishna Pandey <kpandey81930@gmail.com>
This PR adds the following basic math functions for BFloat16 type along
with the tests:
- nextafterbf16
- nextdownbf16
- nexttowardbf16
- nextupbf16
---------
Signed-off-by: Krishna Pandey <kpandey81930@gmail.com>
Co-authored-by: OverMighty <its.overmighty@gmail.com>
This PR adds the following basic math functions for BFloat16 type along
with the tests:
- fromfpbf16
- fromfpxbf16
- ufromfpbf16
- ufromfpxbf16
---------
Signed-off-by: Krishna Pandey <kpandey81930@gmail.com>
Reverts llvm/llvm-project#146226
The MPFR test uses `mpfr_asinpi` which requires MPFR 4.2.0 or later, but
the Buildbots are running an older version of MPFR.
See https://lab.llvm.org/buildbot/#/builders/104/builds/27743 for
example.
I said I was going to revert the PR until we have a workaround for older
versions of MPFR, but then I forgot and I just disabled the entrypoints
which doesn't fix the Buildbot builds.
The function is implemented using the following Taylor series that's
generated using [python-sympy](https://www.sympy.org/en/index.html), and
it is very accurate for |x| $$\in [0, 0.5]$$ and has been verified using
Geogebra. The range reduction is used for the rest range (0.5, 1].
$$
\frac{\arcsin(x)}{\pi} \approx
\begin{aligned}[t]
& 0.318309886183791x \\
& + 0.0530516476972984x^3 \\
& + 0.0238732414637843x^5 \\
& + 0.0142102627760621x^7 \\
& + 0.00967087327815336x^9 \\
& + 0.00712127941391293x^{11} \\
& + 0.00552355646848375x^{13} \\
& + 0.00444514782463692x^{15} \\
& + 0.00367705242846804x^{17} \\
& + 0.00310721681820837x^{19} + O(x^{21})
\end{aligned}
$$
## Geogebra graph
Closes#132210
Add `CLOCKS_PER_SEC` and the older `CLK_TCK`. Allows the user to define
a `__CLK_TCK` to override if necessary.
Also add an extra column for embedded AArch64 in `time.rst`
Main algorithm:
The Taylor series expansion of `asin(x)` is:
```math
\begin{align*}
asin(x) &= x + x^3 / 6 + 3x^5 / 40 + ... \\
&= x \cdot P(x^2) \\
&= x \cdot P(u) &\text{, where } u = x^2.
\end{align*}
```
For the fast path, we perform range reduction mod 1/64 and use degree-7
(minimax + Taylor) polynomials to approximate `P(x^2)`.
When `|x| >= 0.5`, we use the transformation:
```math
u = \frac{1 + x}{2}
```
and apply half-angle formula to reduce `asin(x)` to:
```math
\begin{align*}
asin(x) &= sign(x) \cdot \left( \frac{\pi}{2} - 2 \cdot asin(\sqrt{u}) \right) \\
&= sign(x) \cdot \left( \frac{\pi}{2} - 2 \cdot \sqrt{u} \cdot P(u) \right).
\end{align*}
```
Since `0.5 <= |x| <= 1`, `|u| <= 0.5`. So we can reuse the polynomial
evaluation of `P(u)` when `|x| < 0.5`.
For the accurate path, we redo the computations in 128-bit precision
with degree-15 (minimax + Taylor) polynomials to approximate `P(u)`.
This PR implements the following 8 functions along with the tests.
```c++
int idivr(fract, fract);
long int idivlr(long fract, long fract);
int idivk(accum, accum);
long int idivlk(long accum, long accum);
unsigned int idivur(unsigned fract, unsigned fract);
unsigned long int idivulr(unsigned long fract, unsigned long fract);
unsigned int idivuk(unsigned accum, unsigned accum);
unsigned long int idivulk(unsigned long accum, unsigned long accum);
```
ref: https://www.iso.org/standard/51126.htmlFixes#129125
---------
Signed-off-by: krishna2803 <kpandey81930@gmail.com>
The docs build action was failing with libc due to checks.rst not
existing in the expected path. This patch adjusts the path to the actual
path which seems to make everything happy. It seems like this did not
show up before as stdfix.rst was not included in a place that actually
caused it to get picked up by sphinx.
