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

[libc][math] Add missing parenthesis in sollya command (#132298)

2025-03-21T01:26:09+00:00

This PR adds the missing opening parenthesis for sollya command comment
in `libc/src/math/generic/cbrtf.cpp#L28`.

Signed-off-by: krishna2803

[libc][math] Add tests and fix some issues with FTZ/DAZ modes. (#113744)

2024-10-26T14:55:20+00:00

[libc] Migrate to using LIBC_NAMESPACE_DECL for namespace declaration (#98597)

2024-07-12T16:28:41+00:00

This is a part of #97655.

Revert "[libc] Migrate to using LIBC_NAMESPACE_DECL for namespace declaration" (#98593)

2024-07-12T07:12:13+00:00

Reverts llvm/llvm-project#98075

bots are broken

[libc] Migrate to using LIBC_NAMESPACE_DECL for namespace declaration (#98075)

2024-07-11T19:35:22+00:00

This is a part of #97655.

[libc][math] Implement cbrtf function correctly rounded to all rounding modes. (#97936)

2024-07-08T14:02:12+00:00

Fixes https://github.com/llvm/llvm-project/issues/92874

Algorithm: Let `x = (-1)^s * 2^e * (1 + m)`.
- Step 1: Range reduction: reduce the exponent with:
```
  y = cbrt(x) = (-1)^s * 2^(floor(e/3)) * 2^((e % 3)/3) * (1 + m)^(1/3)
```
- Step 2: Use the first 4 bit fractional bits of `m` to look up for a
degree-7 polynomial approximation to:
```
  (1 + m)^(1/3) ~ 1 + m * P(m).
```
- Step 3: Perform the multiplication:
```
  2^((e % 3)/3) * (1 + m)^(1/3).
```
- Step 4: Check for exact cases to prevent rounding and clear
`FE_INEXACT` floating point exception.
- Step 5: Combine with the exponent and sign before converting down to
`float` and return.