8995ac0448
Get performance closer to the glibc implementations by adding assembly
fma routines, with runtime feature detection so they are used even if
not compiled with `+fma` (as the distributed standard library is often
not). Glibc uses ifuncs, this implementation stores a function pointer
in an atomic.
Results of CPU flags are also cached in order to avoid repeating the
startup time in calls to different functions. The feature detection code
is a slightly simplified version of `std-detect`.
Musl sources were used as a reference [1].
Fixes: https://github.com/rust-lang/rust/issues/140452 once synced
[1]: c47ad25ea3/src/math/x32/fma.c
libm
A Rust implementations of the C math library.
Usage
libm provides fallback implementations for Rust's float math functions in
core, and the core_float_math feature. If what is available suits your
needs, there is no need to add libm as a dependency.
If more functionality is needed, this crate can also be used directly:
[dependencies]
libm = "0.2.11"
Contributing
Please check CONTRIBUTING.md
Minimum Rust version policy
This crate supports rustc 1.63 and newer.
License
Usage is under the MIT license, available at https://opensource.org/license/mit.
Contribution
Contributions are licensed under both the MIT license and the Apache License, Version 2.0, available at htps://www.apache.org/licenses/LICENSE-2.0. Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as mentioned, without any additional terms or conditions.
See LICENSE.txt for full details.