f16 and bf16 floating point types for Rust
This crate implements a half-precision floating point f16 type for Rust implementing the IEEE
754-2008 standard binary16
a.k.a half format, as well as a bf16 type implementing the
bfloat16 format.
Usage
The f16 and bf16 types provides conversion operations as a normal Rust floating point type, but
since they are primarily leveraged for minimal floating point storage and most major hardware does
not implement them, all math operations are done as an f32 type under the hood. Complex arithmetic
should manually convert to and from f32 for better performance.
This crate provides no_std support by
default so can easily be used in embedded code where a smaller float format is most useful.
Requires Rust 1.58 or greater. If you need support for older versions of Rust, use 1.x versions of this crate.
See the crate documentation for more details.
Optional Features
-
serde- ImplementSerializeandDeserializetraits forf16andbf16. This adds a dependency on theserdecrate. -
use-intrinsics- Use hardware intrinsics forf16andbf16conversions if available on the compiler host target. By default, without this feature, conversions are done only in software, which will be the fallback if the host target does not have hardware support. Available only on Rust nightly channel. -
alloc- Enable use of thealloccrate when not using thestdlibrary.This enables the
vecmodule, which contains zero-copy conversions for theVectype. This allows fast conversion between rawVec<u16>bits andVec<f16>orVec<bf16>arrays, and vice versa. -
std- Enable features that depend on the Ruststdlibrary, including everything in theallocfeature.Enabling the
stdfeature enables runtime CPU feature detection when theuse-intrsincisfeature is also enabled. Without this feature detection, intrinsics are only used when compiler host target supports them. -
num-traits- EnableToPrimitive,FromPrimitive,Num,Float,FloatCoreandBoundedtrait implementations from thenum-traitscrate. -
bytemuck- EnableZeroableandPodtrait implementations from thebytemuckcrate. -
zerocopy- EnableAsBytesandFromBytestrait implementations from thezerocopycrate.
More Documentation
License
This library is distributed under the terms of either of:
- MIT License (http://opensource.org/licenses/MIT)
- Apache License, Version 2.0 (http://www.apache.org/licenses/LICENSE-2.0)
at your option.
This project is REUSE-compliant. Copyrights are retained by their contributors. Some files may include explicit copyright notices and/or license SPDX identifiers. For full authorship information, see the version control history.
Contributing
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 above, without any additional terms or conditions.