llvm-project.git/libc/test/src/math/powf_test.cpp, branch users/nico/python-2

[libc] Move libc_errno.h to libc/src/__support and make LIBC_ERRNO_MODE_SYSTEM to be header-only. (#143187)

2025-06-11T20:25:27+00:00

This is the first step in preparation for:
https://discourse.llvm.org/t/rfc-make-clang-builtin-math-functions-constexpr-with-llvm-libc-to-support-c-23-constexpr-math-functions/86450

[libc] remove errno.h includes (#110934)

2024-10-05T23:31:36+00:00

[libc] Create a separate proxy header for math-function-macros.h (#98430)

2024-07-28T04:38:49+00:00

Fix #98393

[libc][math] Fix exact cases for powf. (#91488)

2024-05-10T15:07:41+00:00

It was reported from the CORE-MATH project that the `powf`
implementation did not round correctly when `x^y` is either exact for
exactly half-way.

This PR deals with the potential exact cases when `y` is an integer `2 <
y < 25`. In such cases, the results of `x^y` is exactly representable in
double precision.

[libc] Add proxy header math_macros.h. (#87598)

2024-04-05T22:21:16+00:00

Context: https://github.com/llvm/llvm-project/pull/87017

- Add proxy header `libc/hdr/math_macros.h` that will:
  - include `` in overlay mode,
- include `"include/llvm-libc-macros/math-macros.h"` in full build mode.
- Its corresponding CMake target `libc.hdr.math_macros` will only depend
on `libc.include.math` and `libc.include.llvm-libc-macros.math_macros`
in full build mode.
- Replace all `#include "include/llvm-libc-macros/math-macros.h"` with
`#include "hdr/math_macros.h"`.
- Add dependency to `libc.hdr.math_macros` CMake target when using
`add_fp_unittest`.
- Update the remaining dependency.
- Update bazel overlay: add `libc:hdr_math_macros` target, and replacing
all dependency on `libc:llvm_libc_macros_math_macros` with
`libc:hdr_math_macros`.

[libc] Remove direct math.h includes (#85324)

2024-03-18T21:19:33+00:00

Reland of #84991

A downstream overlay mode user ran into issues with the isnan macro not
working in our sources with a specific libc configuration. This patch
replaces the last direct includes of math.h with our internal
math_macros.h, along with the necessary build system changes.

[libc] Move libc_errno inside of LIBC_NAMESPACE (#80774)

2024-02-06T09:36:05+00:00

Having libc_errno outside of the namespace causes versioning issues when
trying to link the tests against LLVM-libc. Most of this patch is just
moving libc_errno inside the namespace in tests. This isn't necessary in
the function implementations since those are already inside the
namespace.

[libc][math] Implement powf function correctly rounded to all rounding modes. (#71188)

2023-11-06T21:54:25+00:00

We compute `pow(x, y)` using the formula
```
  pow(x, y) = x^y = 2^(y * log2(x))
```
We follow similar steps as in `log2f(x)` and `exp2f(x)`, by breaking
down into `hi + mid + lo` parts, in which `hi` parts are computed using
the exponent field directly, `mid` parts will use look-up tables, and
`lo` parts are approximated by polynomials.

We add some speedup for common use-cases:
```
  pow(2, y) = exp2(y)
  pow(10, y) = exp10(y)
  pow(x, 2) = x * x
  pow(x, 1/2) = sqrt(x)
  pow(x, -1/2) = rsqrt(x) - to be added
```