--- /dev/null
+{
+ "git": {
+ "sha1": "4c56dab175e41faaa367bae9eba82c555f002859"
+ },
+ "path_in_vcs": ""
+}
\ No newline at end of file
--- /dev/null
+Format: https://www.debian.org/doc/packaging-manuals/copyright-format/1.0/
+Copyright: Kathryn Long <squeeself@gmail.com>
+License: MIT OR Apache-2.0
+
+Files: *
+Copyright: 2021 Kathryn Long <squeeself@gmail.com>
+License: MIT OR Apache-2.0
--- /dev/null
+# Changelog
+
+The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
+and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
+
+## [Unreleased]
+
+## [2.2.1] - 2023-01-08 <a name="2.2.1"></a>
+### Changed
+- Reduced unnecessary bounds checks for SIMD operations on slices. By [@Shnatsel].
+- Further slice conversion optimizations for slices. Resolves [#66].
+
+## [2.2.0] - 2022-12-30 <a name="2.2.0"></a>
+### Added
+- Add `serialize_as_f32` and `serialize_as_string` functions when `serde` cargo feature is enabled.
+ They allowing customizing the serialization by using
+ `#[serde(serialize_with="f16::serialize_as_f32")]` attribute in serde derive macros. Closes [#60].
+- Deserialize now supports deserializing from `f32`, `f64`, and string values in addition to its
+ previous default deserialization. Closes [#60].
+
+### Changed
+- Add `#[inline]` on fallback functions, which improved conversion execution on non-nightly rust
+ by up to 50%. By [@Shnatsel].
+
+## [2.1.0] - 2022-07-18 <a name="2.1.0"></a>
+### Added
+- Add support for target_arch `spirv`. Some traits and functions are unavailble on this
+ architecture. By [@charles-r-earp].
+- Add `total_cmp` method to both float types. Closes [#55], by [@joseluis].
+
+## [2.0.0] - 2022-06-21 <a name="2.0.0"></a>
+### Changed
+- **Breaking Change** Minimum supported Rust version is now 1.58.
+- **Breaking Change** `std` is now enabled as a default cargo feature. Disable default features to
+ continue using `no_std` support.
+- Migrated to Rust Edition 2021.
+- Added `#[must_use]` attributes to functions, as appropriate.
+
+### Fixed
+- Fix a soundness bug with `slice::as_ptr` not correctly using mutable reference. By [@Nilstrieb].
+
+### Added
+- Added `const` conversion methods to both `f16` and `bf16`. These methods never use hardware
+ intrinsics, unlike the current conversion methods, which is why they are separated into new
+ methods. The following `const` methods were added:
+ - `from_f32_const`
+ - `from_f64_const`
+ - `to_f32_const`
+ - `to_f64_const`
+- Added `Neg` trait support for borrowed values `&f16` and `&bf16`. By [@pthariensflame].
+- Added `AsPrimitive` implementations from and to self, `usize`, and `isize`. By [@kali].
+
+### Removed
+- **Breaking Change** The deprecated `serialize` cargo feature has been removed. Use `serde` cargo
+ feature instead.
+- **Breaking Change** The deprecated `consts` module has been removed. Use associated constants on
+ `f16` instead.
+- **Breaking Change** The following deprecated functions have been removed:
+ - `f16::as_bits`
+ - `slice::from_bits_mut`
+ - `slice::to_bits_mut`
+ - `slice::from_bits`
+ - `slice::to_bits`
+ - `vec::from_bits`
+ - `vec::to_bits`
+
+## [1.8.2] - 2021-10-22 <a name="1.8.2"></a>
+### Fixed
+- Remove cargo resolver=2 from manifest to resolve errors in older versions of Rust that still
+ worked with 1.8.0. Going forward, MSRV increases will be major version increases. Fixes [#48].
+
+## [1.8.1] - 2021-10-21 - **Yanked** <a name="1.8.1"></a>
+### ***Yanked***
+*Not recommended due to introducing compilation error in Rust versions that worked with 1.8.0.*
+### Changed
+- Now uses cargo resolver version 2 to prevent dev-dependencies from enabling `std` feature on
+ optional dependencies.
+
+### Fixed
+- Fixed compile failure when `std` feature is not enabled and `num-traits` is enabled under new
+ resolver. Now properly uses `libm` num-traits feature.
+
+## [1.8.0] - 2021-10-13 <a name="1.8.0"></a>
+### Changed
+- Now always implements `Add`, `Div`, `Mul`, `Neg`, `Rem`, and `Sub` traits.
+ Previously, these were only implemented under the `num-traits` feature. Keep in mind they still
+ convert to `f32` and back in the implementation.
+- Minimum supported Rust version is now 1.51.
+- Made crate package [REUSE compliant](https://reuse.software/).
+- Docs now use intra-doc links instead of manual (and hard to maintain) links.
+- The following methods on both `f16` and `bf16` are now `const`:
+ - `to_le_bytes`
+ - `to_be_bytes`
+ - `to_ne_bytes`
+ - `from_le_bytes`
+ - `from_be_bytes`
+ - `from_ne_bytes`
+ - `is_normal`
+ - `classify`
+ - `signum`
+
+### Added
+- Added optional implementations of `zerocopy` traits `AsBytes` and `FromBytes`
+ under `zerocopy` cargo feature. By [@samcrow].
+- Implemented the `core::iter::Product` and `core::iter::Sum` traits, with the same caveat as above
+ about converting to `f32` and back under the hood.
+- Added new associated const `NEG_ONE` to both `f16` and `bf16`.
+- Added the following new methods on both `f16` and `bf16`:
+ - `copysign`
+ - `max`
+ - `min`
+ - `clamp`
+
+### Fixed
+- Fixed a number of minor lints discovered due to improved CI.
+
+## [1.7.1] - 2021-01-17 <a name="1.7.1"></a>
+### Fixed
+- Docs.rs now generates docs for `bytemuck` and `num-traits` optional features.
+
+## [1.7.0] - 2021-01-17 <a name="1.7.0"></a>
+### Added
+- Added optional implementations of `bytemuck` traits `Zeroable` and `Pod` under `bytemuck` cargo
+ feature. By [@charles-r-earp].
+- Added optional implementations of `num-traits` traits `ToPrimitive` and `FromPrimitive` under
+ `num-traits` cargo feature. By [@charles-r-earp].
+- Added implementations of `Binary`, `Octal`, `LowerHex`, and `UpperHex` string format traits to
+ format raw `f16`/`bf16` bytes to string.
+
+### Changed
+- `Debug` trait implementation now formats `f16`/`bf16` as float instead of raw bytes hex. Use newly
+ implemented formatting traits to format in hex instead of `Debug`. Fixes [#37].
+
+
+## [1.6.0] - 2020-05-09 <a name="1.6.0"></a>
+### Added
+- Added `LOG2_10` and `LOG10_2` constants to both `f16` and `bf16`, which were added to `f32` and
+ `f64` in the standard library in 1.43.0. By [@tspiteri].
+- Added `to_le/be/ne_bytes` and `from_le/be/ne_bytes` to both `f16` and `bf16`, which were added to
+ the standard library in 1.40.0. By [@bzm3r].
+
+## [1.5.0] - 2020-03-03 <a name="1.5.0"></a>
+### Added
+- Added the `alloc` feature to support the `alloc` crate in `no_std` environments. By [@zserik]. The
+ `vec` module is now available with either `alloc` or `std` feature.
+
+## [1.4.1] - 2020-02-10 <a name="1.4.1"></a>
+### Fixed
+- Added `#[repr(transparent)]` to `f16`/`bf16` to remove undefined behavior. By [@jfrimmel].
+
+## [1.4.0] - 2019-10-13 <a name="1.4.0"></a>
+### Added
+- Added a `bf16` type implementing the alternative
+ [`bfloat16`](https://en.wikipedia.org/wiki/Bfloat16_floating-point_format) 16-bit floating point
+ format. By [@tspiteri].
+- `f16::from_bits`, `f16::to_bits`, `f16::is_nan`, `f16::is_infinite`, `f16::is_finite`,
+ `f16::is_sign_positive`, and `f16::is_sign_negative` are now `const` fns.
+- `slice::HalfBitsSliceExt` and `slice::HalfBitsSliceExt` extension traits have been added for
+ performing efficient reinterpret casts and conversions of slices to and from `[f16]` and
+ `[bf16]`. These traits will use hardware SIMD conversion instructions when available and the
+ `use-intrinsics` cargo feature is enabled.
+- `vec::HalfBitsVecExt` and `vec::HalfFloatVecExt` extension traits have been added for
+ performing efficient reinterpret casts to and from `Vec<f16>` and `Vec<bf16>`. These traits
+ are only available with the `std` cargo feature.
+- `prelude` has been added, for easy importing of most common functionality. Currently the
+ prelude imports `f16`, `bf16`, and the new slice and vec extension traits.
+- New associated constants on `f16` type to replace deprecated `consts` module.
+
+### Fixed
+- Software conversion (when not using `use-intrinsics` feature) now matches hardware rounding
+ by rounding to nearest, ties to even. Fixes [#24], by [@tspiteri].
+- NaN value conversions now behave like `f32` to `f64` conversions, retaining sign. Fixes [#23],
+ by [@tspiteri].
+
+### Changed
+- Minimum rustc version bumped to 1.32.
+- Runtime target host feature detection is now used if both `std` and `use-intrinsics` features are
+ enabled and the compile target host does not support required features.
+- When `use-intrinsics` feature is enabled, will now always compile and run without error correctly
+ regardless of compile target options.
+
+### Deprecated
+- `consts` module and all its constants have been deprecated; use the associated constants on `f16`
+ instead.
+- `slice::from_bits` has been deprecated; use `slice::HalfBitsSliceExt::reinterpret_cast` instead.
+- `slice::from_bits_mut` has been deprecated; use `slice::HalfBitsSliceExt::reinterpret_cast_mut`
+ instead.
+- `slice::to_bits` has been deprecated; use `slice::HalfFloatSliceExt::reinterpret_cast` instead.
+- `slice::to_bits_mut` has been deprecated; use `slice::HalfFloatSliceExt::reinterpret_cast_mut`
+ instead.
+- `vec::from_bits` has been deprecated; use `vec::HalfBitsVecExt::reinterpret_into` instead.
+- `vec::to_bits` has been deprecated; use `vec::HalfFloatVecExt::reinterpret_into` instead.
+
+## [1.3.1] - 2019-10-04 <a name="1.3.1"></a>
+### Fixed
+- Corrected values of constants `EPSILON`, `MAX_10_EXP`, `MAX_EXP`, `MIN_10_EXP`, and `MIN_EXP`
+ in `consts` module, as well as setting `consts::NAN` to match value of `f32::NAN` converted to
+ `f16`. By [@tspiteri].
+
+## [1.3.0] - 2018-10-02 <a name="1.3.0"></a>
+### Added
+- `slice::from_bits_mut` and `slice::to_bits_mut` for conversion between mutable `u16` and `f16`
+ slices. Fixes [#16], by [@johannesvollmer].
+
+## [1.2.0] - 2018-09-03 <a name="1.2.0"></a>
+### Added
+- `slice` and optional `vec` (only included with `std` feature) modules for conversions between
+ `u16` and `f16` buffers. Fixes [#14], by [@johannesvollmer].
+- `to_bits` added to replace `as_bits`. Fixes [#12], by [@tspiteri].
+### Fixed
+- `serde` optional dependency no longer uses its default `std` feature.
+### Deprecated
+- `as_bits` has been deprecated; use `to_bits` instead.
+- `serialize` cargo feature is deprecated; use `serde` instead.
+
+## [1.1.2] - 2018-07-12 <a name="1.1.2"></a>
+### Fixed
+- Fixed compilation error in 1.1.1 on rustc < 1.27, now compiles again on rustc >= 1.10. Fixes
+ [#11].
+
+## [1.1.1] - 2018-06-24 - **Yanked** <a name="1.1.1"></a>
+### ***Yanked***
+*Not recommended due to introducing compilation error on rustc versions prior to 1.27.*
+### Fixed
+- Fix subnormal float conversions when `use-intrinsics` is not enabled. By [@Moongoodboy-K].
+
+## [1.1.0] - 2018-03-17 <a name="1.1.0"></a>
+### Added
+- Made `to_f32` and `to_f64` public. Fixes [#7], by [@PSeitz].
+
+## [1.0.2] - 2018-01-12 <a name="1.0.2"></a>
+### Changed
+- Update behavior of `is_sign_positive` and `is_sign_negative` to match the IEEE754 conforming
+ behavior of the standard library since Rust 1.20.0. Fixes [#3], by [@tspiteri].
+- Small optimization on `is_nan` and `is_infinite` from [@tspiteri].
+### Fixed
+- Fix comparisons of +0 to -0 and comparisons involving negative numbers. Fixes [#2], by
+ [@tspiteri].
+- Fix loss of sign when converting `f16` and `f32` to `f16`, and case where `f64` NaN could be
+ converted to `f16` infinity instead of NaN. Fixes [#5], by [@tspiteri].
+
+## [1.0.1] - 2017-08-30 <a name="1.0.1"></a>
+### Added
+- More README documentation.
+- Badges and categories in crate metadata.
+### Changed
+- `serde` dependency updated to 1.0 stable.
+- Writing changelog manually.
+
+## [1.0.0] - 2017-02-03 <a name="1.0.0"></a>
+### Added
+- Update to `serde` 0.9 and stable Rust 1.15 for `serialize` feature.
+
+## [0.1.1] - 2017-01-08 <a name="0.1.1"></a>
+### Added
+- Add `serde` support under new `serialize` feature.
+### Changed
+- Use `no_std` for crate by default.
+
+## 0.1.0 - 2016-03-17 <a name="0.1.0"></a>
+### Added
+- Initial release of `f16` type.
+
+[#2]: https://github.com/starkat99/half-rs/issues/2
+[#3]: https://github.com/starkat99/half-rs/issues/3
+[#5]: https://github.com/starkat99/half-rs/issues/5
+[#7]: https://github.com/starkat99/half-rs/issues/7
+[#11]: https://github.com/starkat99/half-rs/issues/11
+[#12]: https://github.com/starkat99/half-rs/issues/12
+[#14]: https://github.com/starkat99/half-rs/issues/14
+[#16]: https://github.com/starkat99/half-rs/issues/16
+[#23]: https://github.com/starkat99/half-rs/issues/23
+[#24]: https://github.com/starkat99/half-rs/issues/24
+[#37]: https://github.com/starkat99/half-rs/issues/37
+[#48]: https://github.com/starkat99/half-rs/issues/48
+[#55]: https://github.com/starkat99/half-rs/issues/55
+[#60]: https://github.com/starkat99/half-rs/issues/60
+[#66]: https://github.com/starkat99/half-rs/issues/66
+
+[@tspiteri]: https://github.com/tspiteri
+[@PSeitz]: https://github.com/PSeitz
+[@Moongoodboy-K]: https://github.com/Moongoodboy-K
+[@johannesvollmer]: https://github.com/johannesvollmer
+[@jfrimmel]: https://github.com/jfrimmel
+[@zserik]: https://github.com/zserik
+[@bzm3r]: https://github.com/bzm3r
+[@charles-r-earp]: https://github.com/charles-r-earp
+[@samcrow]: https://github.com/samcrow
+[@pthariensflame]: https://github.com/pthariensflame
+[@kali]: https://github.com/kali
+[@Nilstrieb]: https://github.com/Nilstrieb
+[@joseluis]: https://github.com/joseluis
+[@Shnatsel]: https://github.com/Shnatsel
+
+
+[Unreleased]: https://github.com/starkat99/half-rs/compare/v2.2.1...HEAD
+[2.2.1]: https://github.com/starkat99/half-rs/compare/v2.2.0...v2.2.1
+[2.2.0]: https://github.com/starkat99/half-rs/compare/v2.1.0...v2.2.0
+[2.1.0]: https://github.com/starkat99/half-rs/compare/v2.0.0...v2.1.0
+[2.0.0]: https://github.com/starkat99/half-rs/compare/v1.8.2...v2.0.0
+[1.8.2]: https://github.com/starkat99/half-rs/compare/v1.8.1...v1.8.2
+[1.8.1]: https://github.com/starkat99/half-rs/compare/v1.8.0...v1.8.1
+[1.8.0]: https://github.com/starkat99/half-rs/compare/v1.7.1...v1.8.0
+[1.7.1]: https://github.com/starkat99/half-rs/compare/v1.7.0...v1.7.1
+[1.7.0]: https://github.com/starkat99/half-rs/compare/v1.6.0...v1.7.0
+[1.6.0]: https://github.com/starkat99/half-rs/compare/v1.5.0...v1.6.0
+[1.5.0]: https://github.com/starkat99/half-rs/compare/v1.4.1...v1.5.0
+[1.4.1]: https://github.com/starkat99/half-rs/compare/v1.4.0...v1.4.1
+[1.4.0]: https://github.com/starkat99/half-rs/compare/v1.3.1...v1.4.0
+[1.3.1]: https://github.com/starkat99/half-rs/compare/v1.3.0...v1.3.1
+[1.3.0]: https://github.com/starkat99/half-rs/compare/v1.2.0...v1.3.0
+[1.2.0]: https://github.com/starkat99/half-rs/compare/v1.1.2...v1.2.0
+[1.1.2]: https://github.com/starkat99/half-rs/compare/v1.1.1...v1.1.2
+[1.1.1]: https://github.com/starkat99/half-rs/compare/v1.1.0...v1.1.1
+[1.1.0]: https://github.com/starkat99/half-rs/compare/v1.0.2...v1.1.0
+[1.0.2]: https://github.com/starkat99/half-rs/compare/v1.0.1...v1.0.2
+[1.0.1]: https://github.com/starkat99/half-rs/compare/v1.0.0...v1.0.1
+[1.0.0]: https://github.com/starkat99/half-rs/compare/v0.1.1...v1.0.0
+[0.1.1]: https://github.com/starkat99/half-rs/compare/v0.1.0...v0.1.1
--- /dev/null
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# When uploading crates to the registry Cargo will automatically
+# "normalize" Cargo.toml files for maximal compatibility
+# with all versions of Cargo and also rewrite `path` dependencies
+# to registry (e.g., crates.io) dependencies.
+#
+# If you are reading this file be aware that the original Cargo.toml
+# will likely look very different (and much more reasonable).
+# See Cargo.toml.orig for the original contents.
+
+[package]
+edition = "2021"
+rust-version = "1.58"
+name = "half"
+version = "2.2.1"
+authors = ["Kathryn Long <squeeself@gmail.com>"]
+exclude = [
+ ".git*",
+ ".editorconfig",
+]
+description = "Half-precision floating point f16 and bf16 types for Rust implementing the IEEE 754-2008 standard binary16 and bfloat16 types."
+readme = "README.md"
+keywords = [
+ "f16",
+ "bfloat16",
+ "no_std",
+]
+categories = [
+ "no-std",
+ "data-structures",
+ "encoding",
+]
+license = "MIT OR Apache-2.0"
+repository = "https://github.com/starkat99/half-rs"
+
+[package.metadata.docs.rs]
+rustc-args = [
+ "--cfg",
+ "docsrs",
+]
+features = [
+ "std",
+ "serde",
+ "bytemuck",
+ "num-traits",
+ "zerocopy",
+]
+
+[[bench]]
+name = "convert"
+harness = false
+
+[dependencies.bytemuck]
+version = "1.4.1"
+features = ["derive"]
+optional = true
+default-features = false
+
+[dependencies.num-traits]
+version = "0.2.14"
+features = ["libm"]
+optional = true
+default-features = false
+
+[dependencies.serde]
+version = "1.0"
+features = ["derive"]
+optional = true
+default-features = false
+
+[dependencies.zerocopy]
+version = "0.6.0"
+optional = true
+default-features = false
+
+[dev-dependencies.criterion]
+version = "0.4.0"
+
+[dev-dependencies.crunchy]
+version = "0.2.2"
+
+[dev-dependencies.quickcheck]
+version = "1.0"
+
+[dev-dependencies.quickcheck_macros]
+version = "1.0"
+
+[dev-dependencies.rand]
+version = "0.8.4"
+
+[features]
+alloc = []
+default = ["std"]
+std = ["alloc"]
+use-intrinsics = []
+
+[target."cfg(target_arch = \"spirv\")".dependencies.crunchy]
+version = "0.2.2"
--- /dev/null
+[package]
+name = "half"
+# Remember to keep in sync with html_root_url crate attribute
+version = "2.2.1"
+authors = ["Kathryn Long <squeeself@gmail.com>"]
+description = "Half-precision floating point f16 and bf16 types for Rust implementing the IEEE 754-2008 standard binary16 and bfloat16 types."
+repository = "https://github.com/starkat99/half-rs"
+readme = "README.md"
+keywords = ["f16", "bfloat16", "no_std"]
+license = "MIT OR Apache-2.0"
+categories = ["no-std", "data-structures", "encoding"]
+edition = "2021"
+rust-version = "1.58"
+exclude = [".git*", ".editorconfig"]
+
+[features]
+default = ["std"]
+std = ["alloc"]
+use-intrinsics = []
+alloc = []
+
+[dependencies]
+bytemuck = { version = "1.4.1", default-features = false, features = [
+ "derive",
+], optional = true }
+serde = { version = "1.0", default-features = false, features = [
+ "derive",
+], optional = true }
+num-traits = { version = "0.2.14", default-features = false, features = ["libm"], optional = true }
+zerocopy = { version = "0.6.0", default-features = false, optional = true }
+
+[target.'cfg(target_arch = "spirv")'.dependencies]
+crunchy = "0.2.2"
+
+[dev-dependencies]
+criterion = "0.4.0"
+quickcheck = "1.0"
+quickcheck_macros = "1.0"
+rand = "0.8.4"
+crunchy = "0.2.2"
+
+[[bench]]
+name = "convert"
+harness = false
+
+[package.metadata.docs.rs]
+rustc-args = ["--cfg", "docsrs"]
+features = ["std", "serde", "bytemuck", "num-traits", "zerocopy"]
--- /dev/null
+MIT OR Apache-2.0
--- /dev/null
+Apache License
+Version 2.0, January 2004
+http://www.apache.org/licenses/
+
+TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+1. Definitions.
+
+"License" shall mean the terms and conditions for use, reproduction, and distribution as defined by Sections 1 through 9 of this document.
+
+"Licensor" shall mean the copyright owner or entity authorized by the copyright owner that is granting the License.
+
+"Legal Entity" shall mean the union of the acting entity and all other entities that control, are controlled by, or are under common control with that entity. For the purposes of this definition, "control" means (i) the power, direct or indirect, to cause the direction or management of such entity, whether by contract or otherwise, or (ii) ownership of fifty percent (50%) or more of the outstanding shares, or (iii) beneficial ownership of such entity.
+
+"You" (or "Your") shall mean an individual or Legal Entity exercising permissions granted by this License.
+
+"Source" form shall mean the preferred form for making modifications, including but not limited to software source code, documentation source, and configuration files.
+
+"Object" form shall mean any form resulting from mechanical transformation or translation of a Source form, including but not limited to compiled object code, generated documentation, and conversions to other media types.
+
+"Work" shall mean the work of authorship, whether in Source or Object form, made available under the License, as indicated by a copyright notice that is included in or attached to the work (an example is provided in the Appendix below).
+
+"Derivative Works" shall mean any work, whether in Source or Object form, that is based on (or derived from) the Work and for which the editorial revisions, annotations, elaborations, or other modifications represent, as a whole, an original work of authorship. For the purposes of this License, Derivative Works shall not include works that remain separable from, or merely link (or bind by name) to the interfaces of, the Work and Derivative Works thereof.
+
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+5. Submission of Contributions. Unless You explicitly state otherwise, any Contribution intentionally submitted for inclusion in the Work by You to the Licensor shall be under the terms and conditions of this License, without any additional terms or conditions. Notwithstanding the above, nothing herein shall supersede or modify the terms of any separate license agreement you may have executed with Licensor regarding such Contributions.
+
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+
+8. Limitation of Liability. In no event and under no legal theory, whether in tort (including negligence), contract, or otherwise, unless required by applicable law (such as deliberate and grossly negligent acts) or agreed to in writing, shall any Contributor be liable to You for damages, including any direct, indirect, special, incidental, or consequential damages of any character arising as a result of this License or out of the use or inability to use the Work (including but not limited to damages for loss of goodwill, work stoppage, computer failure or malfunction, or any and all other commercial damages or losses), even if such Contributor has been advised of the possibility of such damages.
+
+9. Accepting Warranty or Additional Liability. While redistributing the Work or Derivative Works thereof, You may choose to offer, and charge a fee for, acceptance of support, warranty, indemnity, or other liability obligations and/or rights consistent with this License. However, in accepting such obligations, You may act only on Your own behalf and on Your sole responsibility, not on behalf of any other Contributor, and only if You agree to indemnify, defend, and hold each Contributor harmless for any liability incurred by, or claims asserted against, such Contributor by reason of your accepting any such warranty or additional liability.
+
+END OF TERMS AND CONDITIONS
+
+APPENDIX: How to apply the Apache License to your work.
+
+To apply the Apache License to your work, attach the following boilerplate notice, with the fields enclosed by brackets "[]" replaced with your own identifying information. (Don't include the brackets!) The text should be enclosed in the appropriate comment syntax for the file format. We also recommend that a file or class name and description of purpose be included on the same "printed page" as the copyright notice for easier identification within third-party archives.
+
+Copyright [yyyy] [name of copyright owner]
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
--- /dev/null
+MIT License
+
+Copyright (c) <year> <copyright holders>
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
--- /dev/null
+[config]
+min_version = "0.35.0"
+
+[env]
+CI_CARGO_TEST_FLAGS = { value = "--locked -- --nocapture", condition = { env_true = [
+ "CARGO_MAKE_CI",
+] } }
+CARGO_MAKE_CARGO_ALL_FEATURES = { source = "${CARGO_MAKE_RUST_CHANNEL}", default_value = "--features=std,serde,num-traits,bytemuck,zerocopy", mapping = { "nightly" = "--all-features" } }
+CARGO_MAKE_CLIPPY_ARGS = { value = "${CARGO_MAKE_CLIPPY_ALL_FEATURES_WARN}", condition = { env_true = [
+ "CARGO_MAKE_CI",
+] } }
+
+# Override for CI flag additions
+[tasks.test]
+args = [
+ "test",
+ "@@remove-empty(CARGO_MAKE_CARGO_VERBOSE_FLAGS)",
+ "@@split(CARGO_MAKE_CARGO_BUILD_TEST_FLAGS, )",
+ "@@split(CI_CARGO_TEST_FLAGS, )",
+]
+
+# Let clippy run on non-nightly CI
+[tasks.clippy-ci-flow]
+condition = { env_set = ["CARGO_MAKE_RUN_CLIPPY"] }
+
+# Let format check run on non-nightly CI
+[tasks.check-format-ci-flow]
+condition = { env_set = ["CARGO_MAKE_RUN_CHECK_FORMAT"] }
+
+[tasks.check-docs]
+description = "Checks docs for errors."
+category = "Documentation"
+install_crate = false
+env = { RUSTDOCFLAGS = "-D warnings" }
+command = "cargo"
+args = [
+ "doc",
+ "--workspace",
+ "--no-deps",
+ "@@remove-empty(CARGO_MAKE_CARGO_VERBOSE_FLAGS)",
+ "${CARGO_MAKE_CARGO_ALL_FEATURES}",
+]
+
+# Build & Test with no features enabled
+[tasks.post-ci-flow]
+run_task = [{ name = ["check-docs", "build-no-std", "test-no-std"] }]
+
+[tasks.build-no-std]
+description = "Build without any features"
+category = "Build"
+env = { CARGO_MAKE_CARGO_BUILD_TEST_FLAGS = "--no-default-features" }
+run_task = "build"
+
+[tasks.test-no-std]
+description = "Run tests without any features"
+category = "Test"
+env = { CARGO_MAKE_CARGO_BUILD_TEST_FLAGS = "--no-default-features" }
+run_task = "test"
--- /dev/null
+# `f16` and `bf16` floating point types for Rust
+[](https://crates.io/crates/half/) [](https://docs.rs/half/)  [](https://github.com/starkat99/half-rs/actions/workflows/rust.yml)
+
+This crate implements a half-precision floating point `f16` type for Rust implementing the IEEE
+754-2008 standard [`binary16`](https://en.wikipedia.org/wiki/Half-precision_floating-point_format)
+a.k.a `half` format, as well as a `bf16` type implementing the
+[`bfloat16`](https://en.wikipedia.org/wiki/Bfloat16_floating-point_format) 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`](https://rust-embedded.github.io/book/intro/no-std.html) 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](https://docs.rs/half/) for more details.
+
+### Optional Features
+
+- **`serde`** - Implement `Serialize` and `Deserialize` traits for `f16` and `bf16`. This adds a
+ dependency on the [`serde`](https://crates.io/crates/serde) crate.
+
+- **`use-intrinsics`** - Use hardware intrinsics for `f16` and `bf16` conversions 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 the [`alloc`](https://doc.rust-lang.org/alloc/) crate when not using
+ the `std` library.
+
+ This enables the `vec` module, which contains zero-copy conversions for the `Vec` type. This
+ allows fast conversion between raw `Vec<u16>` bits and `Vec<f16>` or `Vec<bf16>` arrays, and vice
+ versa.
+
+- **`std`** - Enable features that depend on the Rust `std` library, including everything in the
+ `alloc` feature.
+
+ Enabling the `std` feature enables runtime CPU feature detection when the `use-intrsincis` feature
+ is also enabled.
+ Without this feature detection, intrinsics are only used when compiler host target supports them.
+
+- **`num-traits`** - Enable `ToPrimitive`, `FromPrimitive`, `Num`, `Float`, `FloatCore` and
+ `Bounded` trait implementations from the [`num-traits`](https://crates.io/crates/num-traits) crate.
+
+- **`bytemuck`** - Enable `Zeroable` and `Pod` trait implementations from the
+ [`bytemuck`](https://crates.io/crates/bytemuck) crate.
+
+- **`zerocopy`** - Enable `AsBytes` and `FromBytes` trait implementations from the
+ [`zerocopy`](https://crates.io/crates/zerocopy) crate.
+
+### More Documentation
+
+- [Crate API Reference](https://docs.rs/half/)
+- [Latest Changes](CHANGELOG.md)
+
+## License
+
+This library is distributed under the terms of either of:
+
+* [MIT License](LICENSES/MIT.txt)
+ ([http://opensource.org/licenses/MIT](http://opensource.org/licenses/MIT))
+* [Apache License, Version 2.0](LICENSES/Apache-2.0.txt)
+ ([http://www.apache.org/licenses/LICENSE-2.0](http://www.apache.org/licenses/LICENSE-2.0))
+
+at your option.
+
+This project is [REUSE-compliant](https://reuse.software/spec/). Copyrights are retained by their
+contributors. Some files may include explicit copyright notices and/or license
+[SPDX identifiers](https://spdx.dev/ids/). 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.
--- /dev/null
+use criterion::{criterion_group, criterion_main, Bencher, BenchmarkId, Criterion};
+use half::prelude::*;
+use std::{f32, f64, iter};
+
+const SIMD_LARGE_BENCH_SLICE_LEN: usize = 1024;
+
+fn bench_f32_to_f16(c: &mut Criterion) {
+ let mut group = c.benchmark_group("Convert f16 From f32");
+ for val in &[
+ 0.,
+ -0.,
+ 1.,
+ f32::MIN,
+ f32::MAX,
+ f32::MIN_POSITIVE,
+ f32::NEG_INFINITY,
+ f32::INFINITY,
+ f32::NAN,
+ f32::consts::E,
+ f32::consts::PI,
+ ] {
+ group.bench_with_input(BenchmarkId::new("f16::from_f32", val), val, |b, i| {
+ b.iter(|| f16::from_f32(*i))
+ });
+ }
+}
+
+fn bench_f64_to_f16(c: &mut Criterion) {
+ let mut group = c.benchmark_group("Convert f16 From f64");
+ for val in &[
+ 0.,
+ -0.,
+ 1.,
+ f64::MIN,
+ f64::MAX,
+ f64::MIN_POSITIVE,
+ f64::NEG_INFINITY,
+ f64::INFINITY,
+ f64::NAN,
+ f64::consts::E,
+ f64::consts::PI,
+ ] {
+ group.bench_with_input(BenchmarkId::new("f16::from_f64", val), val, |b, i| {
+ b.iter(|| f16::from_f64(*i))
+ });
+ }
+}
+
+fn bench_f16_to_f32(c: &mut Criterion) {
+ let mut group = c.benchmark_group("Convert f16 to f32");
+ for val in &[
+ f16::ZERO,
+ f16::NEG_ZERO,
+ f16::ONE,
+ f16::MIN,
+ f16::MAX,
+ f16::MIN_POSITIVE,
+ f16::NEG_INFINITY,
+ f16::INFINITY,
+ f16::NAN,
+ f16::E,
+ f16::PI,
+ ] {
+ group.bench_with_input(BenchmarkId::new("f16::to_f32", val), val, |b, i| {
+ b.iter(|| i.to_f32())
+ });
+ }
+}
+
+fn bench_f16_to_f64(c: &mut Criterion) {
+ let mut group = c.benchmark_group("Convert f16 to f64");
+ for val in &[
+ f16::ZERO,
+ f16::NEG_ZERO,
+ f16::ONE,
+ f16::MIN,
+ f16::MAX,
+ f16::MIN_POSITIVE,
+ f16::NEG_INFINITY,
+ f16::INFINITY,
+ f16::NAN,
+ f16::E,
+ f16::PI,
+ ] {
+ group.bench_with_input(BenchmarkId::new("f16::to_f64", val), val, |b, i| {
+ b.iter(|| i.to_f64())
+ });
+ }
+}
+
+criterion_group!(
+ f16_sisd,
+ bench_f32_to_f16,
+ bench_f64_to_f16,
+ bench_f16_to_f32,
+ bench_f16_to_f64
+);
+
+fn bench_slice_f32_to_f16(c: &mut Criterion) {
+ let mut constant_buffer = [f16::ZERO; 11];
+ let constants = [
+ 0.,
+ -0.,
+ 1.,
+ f32::MIN,
+ f32::MAX,
+ f32::MIN_POSITIVE,
+ f32::NEG_INFINITY,
+ f32::INFINITY,
+ f32::NAN,
+ f32::consts::E,
+ f32::consts::PI,
+ ];
+ c.bench_function(
+ "HalfFloatSliceExt::convert_from_f32_slice/constants",
+ |b: &mut Bencher<'_>| b.iter(|| constant_buffer.convert_from_f32_slice(&constants)),
+ );
+
+ let large: Vec<_> = iter::repeat(0)
+ .enumerate()
+ .map(|(i, _)| i as f32)
+ .take(SIMD_LARGE_BENCH_SLICE_LEN)
+ .collect();
+ let mut large_buffer = [f16::ZERO; SIMD_LARGE_BENCH_SLICE_LEN];
+ c.bench_function(
+ "HalfFloatSliceExt::convert_from_f32_slice/large",
+ |b: &mut Bencher<'_>| b.iter(|| large_buffer.convert_from_f32_slice(&large)),
+ );
+}
+
+fn bench_slice_f64_to_f16(c: &mut Criterion) {
+ let mut constant_buffer = [f16::ZERO; 11];
+ let constants = [
+ 0.,
+ -0.,
+ 1.,
+ f64::MIN,
+ f64::MAX,
+ f64::MIN_POSITIVE,
+ f64::NEG_INFINITY,
+ f64::INFINITY,
+ f64::NAN,
+ f64::consts::E,
+ f64::consts::PI,
+ ];
+ c.bench_function(
+ "HalfFloatSliceExt::convert_from_f64_slice/constants",
+ |b: &mut Bencher<'_>| b.iter(|| constant_buffer.convert_from_f64_slice(&constants)),
+ );
+
+ let large: Vec<_> = iter::repeat(0)
+ .enumerate()
+ .map(|(i, _)| i as f64)
+ .take(SIMD_LARGE_BENCH_SLICE_LEN)
+ .collect();
+ let mut large_buffer = [f16::ZERO; SIMD_LARGE_BENCH_SLICE_LEN];
+ c.bench_function(
+ "HalfFloatSliceExt::convert_from_f64_slice/large",
+ |b: &mut Bencher<'_>| b.iter(|| large_buffer.convert_from_f64_slice(&large)),
+ );
+}
+
+fn bench_slice_f16_to_f32(c: &mut Criterion) {
+ let mut constant_buffer = [0f32; 11];
+ let constants = [
+ f16::ZERO,
+ f16::NEG_ZERO,
+ f16::ONE,
+ f16::MIN,
+ f16::MAX,
+ f16::MIN_POSITIVE,
+ f16::NEG_INFINITY,
+ f16::INFINITY,
+ f16::NAN,
+ f16::E,
+ f16::PI,
+ ];
+ c.bench_function(
+ "HalfFloatSliceExt::convert_to_f32_slice/constants",
+ |b: &mut Bencher<'_>| b.iter(|| constants.convert_to_f32_slice(&mut constant_buffer)),
+ );
+
+ let large: Vec<_> = iter::repeat(0)
+ .enumerate()
+ .map(|(i, _)| f16::from_f32(i as f32))
+ .take(SIMD_LARGE_BENCH_SLICE_LEN)
+ .collect();
+ let mut large_buffer = [0f32; SIMD_LARGE_BENCH_SLICE_LEN];
+ c.bench_function(
+ "HalfFloatSliceExt::convert_to_f32_slice/large",
+ |b: &mut Bencher<'_>| b.iter(|| large.convert_to_f32_slice(&mut large_buffer)),
+ );
+}
+
+fn bench_slice_f16_to_f64(c: &mut Criterion) {
+ let mut constant_buffer = [0f64; 11];
+ let constants = [
+ f16::ZERO,
+ f16::NEG_ZERO,
+ f16::ONE,
+ f16::MIN,
+ f16::MAX,
+ f16::MIN_POSITIVE,
+ f16::NEG_INFINITY,
+ f16::INFINITY,
+ f16::NAN,
+ f16::E,
+ f16::PI,
+ ];
+ c.bench_function(
+ "HalfFloatSliceExt::convert_to_f64_slice/constants",
+ |b: &mut Bencher<'_>| b.iter(|| constants.convert_to_f64_slice(&mut constant_buffer)),
+ );
+
+ let large: Vec<_> = iter::repeat(0)
+ .enumerate()
+ .map(|(i, _)| f16::from_f64(i as f64))
+ .take(SIMD_LARGE_BENCH_SLICE_LEN)
+ .collect();
+ let mut large_buffer = [0f64; SIMD_LARGE_BENCH_SLICE_LEN];
+ c.bench_function(
+ "HalfFloatSliceExt::convert_to_f64_slice/large",
+ |b: &mut Bencher<'_>| b.iter(|| large.convert_to_f64_slice(&mut large_buffer)),
+ );
+}
+
+criterion_group!(
+ f16_simd,
+ bench_slice_f32_to_f16,
+ bench_slice_f64_to_f16,
+ bench_slice_f16_to_f32,
+ bench_slice_f16_to_f64
+);
+
+fn bench_f32_to_bf16(c: &mut Criterion) {
+ let mut group = c.benchmark_group("Convert bf16 From f32");
+ for val in &[
+ 0.,
+ -0.,
+ 1.,
+ f32::MIN,
+ f32::MAX,
+ f32::MIN_POSITIVE,
+ f32::NEG_INFINITY,
+ f32::INFINITY,
+ f32::NAN,
+ f32::consts::E,
+ f32::consts::PI,
+ ] {
+ group.bench_with_input(BenchmarkId::new("bf16::from_f32", val), val, |b, i| {
+ b.iter(|| bf16::from_f32(*i))
+ });
+ }
+}
+
+fn bench_f64_to_bf16(c: &mut Criterion) {
+ let mut group = c.benchmark_group("Convert bf16 From f64");
+ for val in &[
+ 0.,
+ -0.,
+ 1.,
+ f64::MIN,
+ f64::MAX,
+ f64::MIN_POSITIVE,
+ f64::NEG_INFINITY,
+ f64::INFINITY,
+ f64::NAN,
+ f64::consts::E,
+ f64::consts::PI,
+ ] {
+ group.bench_with_input(BenchmarkId::new("bf16::from_f64", val), val, |b, i| {
+ b.iter(|| bf16::from_f64(*i))
+ });
+ }
+}
+
+fn bench_bf16_to_f32(c: &mut Criterion) {
+ let mut group = c.benchmark_group("Convert bf16 to f32");
+ for val in &[
+ bf16::ZERO,
+ bf16::NEG_ZERO,
+ bf16::ONE,
+ bf16::MIN,
+ bf16::MAX,
+ bf16::MIN_POSITIVE,
+ bf16::NEG_INFINITY,
+ bf16::INFINITY,
+ bf16::NAN,
+ bf16::E,
+ bf16::PI,
+ ] {
+ group.bench_with_input(BenchmarkId::new("bf16::to_f32", val), val, |b, i| {
+ b.iter(|| i.to_f32())
+ });
+ }
+}
+
+fn bench_bf16_to_f64(c: &mut Criterion) {
+ let mut group = c.benchmark_group("Convert bf16 to f64");
+ for val in &[
+ bf16::ZERO,
+ bf16::NEG_ZERO,
+ bf16::ONE,
+ bf16::MIN,
+ bf16::MAX,
+ bf16::MIN_POSITIVE,
+ bf16::NEG_INFINITY,
+ bf16::INFINITY,
+ bf16::NAN,
+ bf16::E,
+ bf16::PI,
+ ] {
+ group.bench_with_input(BenchmarkId::new("bf16::to_f64", val), val, |b, i| {
+ b.iter(|| i.to_f64())
+ });
+ }
+}
+
+criterion_group!(
+ bf16_sisd,
+ bench_f32_to_bf16,
+ bench_f64_to_bf16,
+ bench_bf16_to_f32,
+ bench_bf16_to_f64
+);
+
+criterion_main!(f16_sisd, bf16_sisd, f16_simd);
--- /dev/null
+#[cfg(feature = "bytemuck")]
+use bytemuck::{Pod, Zeroable};
+use core::{
+ cmp::Ordering,
+ iter::{Product, Sum},
+ num::FpCategory,
+ ops::{Add, AddAssign, Div, DivAssign, Mul, MulAssign, Neg, Rem, RemAssign, Sub, SubAssign},
+};
+#[cfg(not(target_arch = "spirv"))]
+use core::{
+ fmt::{
+ Binary, Debug, Display, Error, Formatter, LowerExp, LowerHex, Octal, UpperExp, UpperHex,
+ },
+ num::ParseFloatError,
+ str::FromStr,
+};
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
+#[cfg(feature = "zerocopy")]
+use zerocopy::{AsBytes, FromBytes};
+
+pub(crate) mod convert;
+
+/// A 16-bit floating point type implementing the [`bfloat16`] format.
+///
+/// The [`bfloat16`] floating point format is a truncated 16-bit version of the IEEE 754 standard
+/// `binary32`, a.k.a [`f32`]. [`bf16`] has approximately the same dynamic range as [`f32`] by
+/// having a lower precision than [`f16`][crate::f16]. While [`f16`][crate::f16] has a precision of
+/// 11 bits, [`bf16`] has a precision of only 8 bits.
+///
+/// Like [`f16`][crate::f16], [`bf16`] does not offer arithmetic operations as it is intended for
+/// compact storage rather than calculations. Operations should be performed with [`f32`] or
+/// higher-precision types and converted to/from [`bf16`] as necessary.
+///
+/// [`bfloat16`]: https://en.wikipedia.org/wiki/Bfloat16_floating-point_format
+#[allow(non_camel_case_types)]
+#[derive(Clone, Copy, Default)]
+#[repr(transparent)]
+#[cfg_attr(feature = "serde", derive(Serialize))]
+#[cfg_attr(feature = "bytemuck", derive(Zeroable, Pod))]
+#[cfg_attr(feature = "zerocopy", derive(AsBytes, FromBytes))]
+pub struct bf16(u16);
+
+impl bf16 {
+ /// Constructs a [`bf16`] value from the raw bits.
+ #[inline]
+ #[must_use]
+ pub const fn from_bits(bits: u16) -> bf16 {
+ bf16(bits)
+ }
+
+ /// Constructs a [`bf16`] value from a 32-bit floating point value.
+ ///
+ /// If the 32-bit value is too large to fit, ±∞ will result. NaN values are preserved.
+ /// Subnormal values that are too tiny to be represented will result in ±0. All other values
+ /// are truncated and rounded to the nearest representable value.
+ #[inline]
+ #[must_use]
+ pub fn from_f32(value: f32) -> bf16 {
+ Self::from_f32_const(value)
+ }
+
+ /// Constructs a [`bf16`] value from a 32-bit floating point value.
+ ///
+ /// This function is identical to [`from_f32`][Self::from_f32] except it never uses hardware
+ /// intrinsics, which allows it to be `const`. [`from_f32`][Self::from_f32] should be preferred
+ /// in any non-`const` context.
+ ///
+ /// If the 32-bit value is too large to fit, ±∞ will result. NaN values are preserved.
+ /// Subnormal values that are too tiny to be represented will result in ±0. All other values
+ /// are truncated and rounded to the nearest representable value.
+ #[inline]
+ #[must_use]
+ pub const fn from_f32_const(value: f32) -> bf16 {
+ bf16(convert::f32_to_bf16(value))
+ }
+
+ /// Constructs a [`bf16`] value from a 64-bit floating point value.
+ ///
+ /// If the 64-bit value is to large to fit, ±∞ will result. NaN values are preserved.
+ /// 64-bit subnormal values are too tiny to be represented and result in ±0. Exponents that
+ /// underflow the minimum exponent will result in subnormals or ±0. All other values are
+ /// truncated and rounded to the nearest representable value.
+ #[inline]
+ #[must_use]
+ pub fn from_f64(value: f64) -> bf16 {
+ Self::from_f64_const(value)
+ }
+
+ /// Constructs a [`bf16`] value from a 64-bit floating point value.
+ ///
+ /// This function is identical to [`from_f64`][Self::from_f64] except it never uses hardware
+ /// intrinsics, which allows it to be `const`. [`from_f64`][Self::from_f64] should be preferred
+ /// in any non-`const` context.
+ ///
+ /// If the 64-bit value is to large to fit, ±∞ will result. NaN values are preserved.
+ /// 64-bit subnormal values are too tiny to be represented and result in ±0. Exponents that
+ /// underflow the minimum exponent will result in subnormals or ±0. All other values are
+ /// truncated and rounded to the nearest representable value.
+ #[inline]
+ #[must_use]
+ pub const fn from_f64_const(value: f64) -> bf16 {
+ bf16(convert::f64_to_bf16(value))
+ }
+
+ /// Converts a [`bf16`] into the underlying bit representation.
+ #[inline]
+ #[must_use]
+ pub const fn to_bits(self) -> u16 {
+ self.0
+ }
+
+ /// Returns the memory representation of the underlying bit representation as a byte array in
+ /// little-endian byte order.
+ ///
+ /// # Examples
+ ///
+ /// ```rust
+ /// # use half::prelude::*;
+ /// let bytes = bf16::from_f32(12.5).to_le_bytes();
+ /// assert_eq!(bytes, [0x48, 0x41]);
+ /// ```
+ #[inline]
+ #[must_use]
+ pub const fn to_le_bytes(self) -> [u8; 2] {
+ self.0.to_le_bytes()
+ }
+
+ /// Returns the memory representation of the underlying bit representation as a byte array in
+ /// big-endian (network) byte order.
+ ///
+ /// # Examples
+ ///
+ /// ```rust
+ /// # use half::prelude::*;
+ /// let bytes = bf16::from_f32(12.5).to_be_bytes();
+ /// assert_eq!(bytes, [0x41, 0x48]);
+ /// ```
+ #[inline]
+ #[must_use]
+ pub const fn to_be_bytes(self) -> [u8; 2] {
+ self.0.to_be_bytes()
+ }
+
+ /// Returns the memory representation of the underlying bit representation as a byte array in
+ /// native byte order.
+ ///
+ /// As the target platform's native endianness is used, portable code should use
+ /// [`to_be_bytes`][bf16::to_be_bytes] or [`to_le_bytes`][bf16::to_le_bytes], as appropriate,
+ /// instead.
+ ///
+ /// # Examples
+ ///
+ /// ```rust
+ /// # use half::prelude::*;
+ /// let bytes = bf16::from_f32(12.5).to_ne_bytes();
+ /// assert_eq!(bytes, if cfg!(target_endian = "big") {
+ /// [0x41, 0x48]
+ /// } else {
+ /// [0x48, 0x41]
+ /// });
+ /// ```
+ #[inline]
+ #[must_use]
+ pub const fn to_ne_bytes(self) -> [u8; 2] {
+ self.0.to_ne_bytes()
+ }
+
+ /// Creates a floating point value from its representation as a byte array in little endian.
+ ///
+ /// # Examples
+ ///
+ /// ```rust
+ /// # use half::prelude::*;
+ /// let value = bf16::from_le_bytes([0x48, 0x41]);
+ /// assert_eq!(value, bf16::from_f32(12.5));
+ /// ```
+ #[inline]
+ #[must_use]
+ pub const fn from_le_bytes(bytes: [u8; 2]) -> bf16 {
+ bf16::from_bits(u16::from_le_bytes(bytes))
+ }
+
+ /// Creates a floating point value from its representation as a byte array in big endian.
+ ///
+ /// # Examples
+ ///
+ /// ```rust
+ /// # use half::prelude::*;
+ /// let value = bf16::from_be_bytes([0x41, 0x48]);
+ /// assert_eq!(value, bf16::from_f32(12.5));
+ /// ```
+ #[inline]
+ #[must_use]
+ pub const fn from_be_bytes(bytes: [u8; 2]) -> bf16 {
+ bf16::from_bits(u16::from_be_bytes(bytes))
+ }
+
+ /// Creates a floating point value from its representation as a byte array in native endian.
+ ///
+ /// As the target platform's native endianness is used, portable code likely wants to use
+ /// [`from_be_bytes`][bf16::from_be_bytes] or [`from_le_bytes`][bf16::from_le_bytes], as
+ /// appropriate instead.
+ ///
+ /// # Examples
+ ///
+ /// ```rust
+ /// # use half::prelude::*;
+ /// let value = bf16::from_ne_bytes(if cfg!(target_endian = "big") {
+ /// [0x41, 0x48]
+ /// } else {
+ /// [0x48, 0x41]
+ /// });
+ /// assert_eq!(value, bf16::from_f32(12.5));
+ /// ```
+ #[inline]
+ #[must_use]
+ pub const fn from_ne_bytes(bytes: [u8; 2]) -> bf16 {
+ bf16::from_bits(u16::from_ne_bytes(bytes))
+ }
+
+ /// Converts a [`bf16`] value into an [`f32`] value.
+ ///
+ /// This conversion is lossless as all values can be represented exactly in [`f32`].
+ #[inline]
+ #[must_use]
+ pub fn to_f32(self) -> f32 {
+ self.to_f32_const()
+ }
+
+ /// Converts a [`bf16`] value into an [`f32`] value.
+ ///
+ /// This function is identical to [`to_f32`][Self::to_f32] except it never uses hardware
+ /// intrinsics, which allows it to be `const`. [`to_f32`][Self::to_f32] should be preferred
+ /// in any non-`const` context.
+ ///
+ /// This conversion is lossless as all values can be represented exactly in [`f32`].
+ #[inline]
+ #[must_use]
+ pub const fn to_f32_const(self) -> f32 {
+ convert::bf16_to_f32(self.0)
+ }
+
+ /// Converts a [`bf16`] value into an [`f64`] value.
+ ///
+ /// This conversion is lossless as all values can be represented exactly in [`f64`].
+ #[inline]
+ #[must_use]
+ pub fn to_f64(self) -> f64 {
+ self.to_f64_const()
+ }
+
+ /// Converts a [`bf16`] value into an [`f64`] value.
+ ///
+ /// This function is identical to [`to_f64`][Self::to_f64] except it never uses hardware
+ /// intrinsics, which allows it to be `const`. [`to_f64`][Self::to_f64] should be preferred
+ /// in any non-`const` context.
+ ///
+ /// This conversion is lossless as all values can be represented exactly in [`f64`].
+ #[inline]
+ #[must_use]
+ pub const fn to_f64_const(self) -> f64 {
+ convert::bf16_to_f64(self.0)
+ }
+
+ /// Returns `true` if this value is NaN and `false` otherwise.
+ ///
+ /// # Examples
+ ///
+ /// ```rust
+ /// # use half::prelude::*;
+ ///
+ /// let nan = bf16::NAN;
+ /// let f = bf16::from_f32(7.0_f32);
+ ///
+ /// assert!(nan.is_nan());
+ /// assert!(!f.is_nan());
+ /// ```
+ #[inline]
+ #[must_use]
+ pub const fn is_nan(self) -> bool {
+ self.0 & 0x7FFFu16 > 0x7F80u16
+ }
+
+ /// Returns `true` if this value is ±∞ and `false` otherwise.
+ ///
+ /// # Examples
+ ///
+ /// ```rust
+ /// # use half::prelude::*;
+ ///
+ /// let f = bf16::from_f32(7.0f32);
+ /// let inf = bf16::INFINITY;
+ /// let neg_inf = bf16::NEG_INFINITY;
+ /// let nan = bf16::NAN;
+ ///
+ /// assert!(!f.is_infinite());
+ /// assert!(!nan.is_infinite());
+ ///
+ /// assert!(inf.is_infinite());
+ /// assert!(neg_inf.is_infinite());
+ /// ```
+ #[inline]
+ #[must_use]
+ pub const fn is_infinite(self) -> bool {
+ self.0 & 0x7FFFu16 == 0x7F80u16
+ }
+
+ /// Returns `true` if this number is neither infinite nor NaN.
+ ///
+ /// # Examples
+ ///
+ /// ```rust
+ /// # use half::prelude::*;
+ ///
+ /// let f = bf16::from_f32(7.0f32);
+ /// let inf = bf16::INFINITY;
+ /// let neg_inf = bf16::NEG_INFINITY;
+ /// let nan = bf16::NAN;
+ ///
+ /// assert!(f.is_finite());
+ ///
+ /// assert!(!nan.is_finite());
+ /// assert!(!inf.is_finite());
+ /// assert!(!neg_inf.is_finite());
+ /// ```
+ #[inline]
+ #[must_use]
+ pub const fn is_finite(self) -> bool {
+ self.0 & 0x7F80u16 != 0x7F80u16
+ }
+
+ /// Returns `true` if the number is neither zero, infinite, subnormal, or NaN.
+ ///
+ /// # Examples
+ ///
+ /// ```rust
+ /// # use half::prelude::*;
+ ///
+ /// let min = bf16::MIN_POSITIVE;
+ /// let max = bf16::MAX;
+ /// let lower_than_min = bf16::from_f32(1.0e-39_f32);
+ /// let zero = bf16::from_f32(0.0_f32);
+ ///
+ /// assert!(min.is_normal());
+ /// assert!(max.is_normal());
+ ///
+ /// assert!(!zero.is_normal());
+ /// assert!(!bf16::NAN.is_normal());
+ /// assert!(!bf16::INFINITY.is_normal());
+ /// // Values between 0 and `min` are subnormal.
+ /// assert!(!lower_than_min.is_normal());
+ /// ```
+ #[inline]
+ #[must_use]
+ pub const fn is_normal(self) -> bool {
+ let exp = self.0 & 0x7F80u16;
+ exp != 0x7F80u16 && exp != 0
+ }
+
+ /// Returns the floating point category of the number.
+ ///
+ /// If only one property is going to be tested, it is generally faster to use the specific
+ /// predicate instead.
+ ///
+ /// # Examples
+ ///
+ /// ```rust
+ /// use std::num::FpCategory;
+ /// # use half::prelude::*;
+ ///
+ /// let num = bf16::from_f32(12.4_f32);
+ /// let inf = bf16::INFINITY;
+ ///
+ /// assert_eq!(num.classify(), FpCategory::Normal);
+ /// assert_eq!(inf.classify(), FpCategory::Infinite);
+ /// ```
+ #[must_use]
+ pub const fn classify(self) -> FpCategory {
+ let exp = self.0 & 0x7F80u16;
+ let man = self.0 & 0x007Fu16;
+ match (exp, man) {
+ (0, 0) => FpCategory::Zero,
+ (0, _) => FpCategory::Subnormal,
+ (0x7F80u16, 0) => FpCategory::Infinite,
+ (0x7F80u16, _) => FpCategory::Nan,
+ _ => FpCategory::Normal,
+ }
+ }
+
+ /// Returns a number that represents the sign of `self`.
+ ///
+ /// * 1.0 if the number is positive, +0.0 or [`INFINITY`][bf16::INFINITY]
+ /// * −1.0 if the number is negative, −0.0` or [`NEG_INFINITY`][bf16::NEG_INFINITY]
+ /// * [`NAN`][bf16::NAN] if the number is NaN
+ ///
+ /// # Examples
+ ///
+ /// ```rust
+ /// # use half::prelude::*;
+ ///
+ /// let f = bf16::from_f32(3.5_f32);
+ ///
+ /// assert_eq!(f.signum(), bf16::from_f32(1.0));
+ /// assert_eq!(bf16::NEG_INFINITY.signum(), bf16::from_f32(-1.0));
+ ///
+ /// assert!(bf16::NAN.signum().is_nan());
+ /// ```
+ #[must_use]
+ pub const fn signum(self) -> bf16 {
+ if self.is_nan() {
+ self
+ } else if self.0 & 0x8000u16 != 0 {
+ Self::NEG_ONE
+ } else {
+ Self::ONE
+ }
+ }
+
+ /// Returns `true` if and only if `self` has a positive sign, including +0.0, NaNs with a
+ /// positive sign bit and +∞.
+ ///
+ /// # Examples
+ ///
+ /// ```rust
+ /// # use half::prelude::*;
+ ///
+ /// let nan = bf16::NAN;
+ /// let f = bf16::from_f32(7.0_f32);
+ /// let g = bf16::from_f32(-7.0_f32);
+ ///
+ /// assert!(f.is_sign_positive());
+ /// assert!(!g.is_sign_positive());
+ /// // NaN can be either positive or negative
+ /// assert!(nan.is_sign_positive() != nan.is_sign_negative());
+ /// ```
+ #[inline]
+ #[must_use]
+ pub const fn is_sign_positive(self) -> bool {
+ self.0 & 0x8000u16 == 0
+ }
+
+ /// Returns `true` if and only if `self` has a negative sign, including −0.0, NaNs with a
+ /// negative sign bit and −∞.
+ ///
+ /// # Examples
+ ///
+ /// ```rust
+ /// # use half::prelude::*;
+ ///
+ /// let nan = bf16::NAN;
+ /// let f = bf16::from_f32(7.0f32);
+ /// let g = bf16::from_f32(-7.0f32);
+ ///
+ /// assert!(!f.is_sign_negative());
+ /// assert!(g.is_sign_negative());
+ /// // NaN can be either positive or negative
+ /// assert!(nan.is_sign_positive() != nan.is_sign_negative());
+ /// ```
+ #[inline]
+ #[must_use]
+ pub const fn is_sign_negative(self) -> bool {
+ self.0 & 0x8000u16 != 0
+ }
+
+ /// Returns a number composed of the magnitude of `self` and the sign of `sign`.
+ ///
+ /// Equal to `self` if the sign of `self` and `sign` are the same, otherwise equal to `-self`.
+ /// If `self` is NaN, then NaN with the sign of `sign` is returned.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// # use half::prelude::*;
+ /// let f = bf16::from_f32(3.5);
+ ///
+ /// assert_eq!(f.copysign(bf16::from_f32(0.42)), bf16::from_f32(3.5));
+ /// assert_eq!(f.copysign(bf16::from_f32(-0.42)), bf16::from_f32(-3.5));
+ /// assert_eq!((-f).copysign(bf16::from_f32(0.42)), bf16::from_f32(3.5));
+ /// assert_eq!((-f).copysign(bf16::from_f32(-0.42)), bf16::from_f32(-3.5));
+ ///
+ /// assert!(bf16::NAN.copysign(bf16::from_f32(1.0)).is_nan());
+ /// ```
+ #[inline]
+ #[must_use]
+ pub const fn copysign(self, sign: bf16) -> bf16 {
+ bf16((sign.0 & 0x8000u16) | (self.0 & 0x7FFFu16))
+ }
+
+ /// Returns the maximum of the two numbers.
+ ///
+ /// If one of the arguments is NaN, then the other argument is returned.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// # use half::prelude::*;
+ /// let x = bf16::from_f32(1.0);
+ /// let y = bf16::from_f32(2.0);
+ ///
+ /// assert_eq!(x.max(y), y);
+ /// ```
+ #[inline]
+ #[must_use]
+ pub fn max(self, other: bf16) -> bf16 {
+ if other > self && !other.is_nan() {
+ other
+ } else {
+ self
+ }
+ }
+
+ /// Returns the minimum of the two numbers.
+ ///
+ /// If one of the arguments is NaN, then the other argument is returned.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// # use half::prelude::*;
+ /// let x = bf16::from_f32(1.0);
+ /// let y = bf16::from_f32(2.0);
+ ///
+ /// assert_eq!(x.min(y), x);
+ /// ```
+ #[inline]
+ #[must_use]
+ pub fn min(self, other: bf16) -> bf16 {
+ if other < self && !other.is_nan() {
+ other
+ } else {
+ self
+ }
+ }
+
+ /// Restrict a value to a certain interval unless it is NaN.
+ ///
+ /// Returns `max` if `self` is greater than `max`, and `min` if `self` is less than `min`.
+ /// Otherwise this returns `self`.
+ ///
+ /// Note that this function returns NaN if the initial value was NaN as well.
+ ///
+ /// # Panics
+ /// Panics if `min > max`, `min` is NaN, or `max` is NaN.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// # use half::prelude::*;
+ /// assert!(bf16::from_f32(-3.0).clamp(bf16::from_f32(-2.0), bf16::from_f32(1.0)) == bf16::from_f32(-2.0));
+ /// assert!(bf16::from_f32(0.0).clamp(bf16::from_f32(-2.0), bf16::from_f32(1.0)) == bf16::from_f32(0.0));
+ /// assert!(bf16::from_f32(2.0).clamp(bf16::from_f32(-2.0), bf16::from_f32(1.0)) == bf16::from_f32(1.0));
+ /// assert!(bf16::NAN.clamp(bf16::from_f32(-2.0), bf16::from_f32(1.0)).is_nan());
+ /// ```
+ #[inline]
+ #[must_use]
+ pub fn clamp(self, min: bf16, max: bf16) -> bf16 {
+ assert!(min <= max);
+ let mut x = self;
+ if x < min {
+ x = min;
+ }
+ if x > max {
+ x = max;
+ }
+ x
+ }
+
+ /// Returns the ordering between `self` and `other`.
+ ///
+ /// Unlike the standard partial comparison between floating point numbers,
+ /// this comparison always produces an ordering in accordance to
+ /// the `totalOrder` predicate as defined in the IEEE 754 (2008 revision)
+ /// floating point standard. The values are ordered in the following sequence:
+ ///
+ /// - negative quiet NaN
+ /// - negative signaling NaN
+ /// - negative infinity
+ /// - negative numbers
+ /// - negative subnormal numbers
+ /// - negative zero
+ /// - positive zero
+ /// - positive subnormal numbers
+ /// - positive numbers
+ /// - positive infinity
+ /// - positive signaling NaN
+ /// - positive quiet NaN.
+ ///
+ /// The ordering established by this function does not always agree with the
+ /// [`PartialOrd`] and [`PartialEq`] implementations of `bf16`. For example,
+ /// they consider negative and positive zero equal, while `total_cmp`
+ /// doesn't.
+ ///
+ /// The interpretation of the signaling NaN bit follows the definition in
+ /// the IEEE 754 standard, which may not match the interpretation by some of
+ /// the older, non-conformant (e.g. MIPS) hardware implementations.
+ ///
+ /// # Examples
+ /// ```
+ /// # use half::bf16;
+ /// let mut v: Vec<bf16> = vec![];
+ /// v.push(bf16::ONE);
+ /// v.push(bf16::INFINITY);
+ /// v.push(bf16::NEG_INFINITY);
+ /// v.push(bf16::NAN);
+ /// v.push(bf16::MAX_SUBNORMAL);
+ /// v.push(-bf16::MAX_SUBNORMAL);
+ /// v.push(bf16::ZERO);
+ /// v.push(bf16::NEG_ZERO);
+ /// v.push(bf16::NEG_ONE);
+ /// v.push(bf16::MIN_POSITIVE);
+ ///
+ /// v.sort_by(|a, b| a.total_cmp(&b));
+ ///
+ /// assert!(v
+ /// .into_iter()
+ /// .zip(
+ /// [
+ /// bf16::NEG_INFINITY,
+ /// bf16::NEG_ONE,
+ /// -bf16::MAX_SUBNORMAL,
+ /// bf16::NEG_ZERO,
+ /// bf16::ZERO,
+ /// bf16::MAX_SUBNORMAL,
+ /// bf16::MIN_POSITIVE,
+ /// bf16::ONE,
+ /// bf16::INFINITY,
+ /// bf16::NAN
+ /// ]
+ /// .iter()
+ /// )
+ /// .all(|(a, b)| a.to_bits() == b.to_bits()));
+ /// ```
+ // Implementation based on: https://doc.rust-lang.org/std/primitive.f32.html#method.total_cmp
+ #[inline]
+ #[must_use]
+ pub fn total_cmp(&self, other: &Self) -> Ordering {
+ let mut left = self.to_bits() as i16;
+ let mut right = other.to_bits() as i16;
+ left ^= (((left >> 15) as u16) >> 1) as i16;
+ right ^= (((right >> 15) as u16) >> 1) as i16;
+ left.cmp(&right)
+ }
+
+ /// Alternate serialize adapter for serializing as a float.
+ ///
+ /// By default, [`bf16`] serializes as a newtype of [`u16`]. This is an alternate serialize
+ /// implementation that serializes as an [`f32`] value. It is designed for use with
+ /// `serialize_with` serde attributes. Deserialization from `f32` values is already supported by
+ /// the default deserialize implementation.
+ ///
+ /// # Examples
+ ///
+ /// A demonstration on how to use this adapater:
+ ///
+ /// ```
+ /// use serde::{Serialize, Deserialize};
+ /// use half::bf16;
+ ///
+ /// #[derive(Serialize, Deserialize)]
+ /// struct MyStruct {
+ /// #[serde(serialize_with = "bf16::serialize_as_f32")]
+ /// value: bf16 // Will be serialized as f32 instead of u16
+ /// }
+ /// ```
+ #[cfg(feature = "serde")]
+ pub fn serialize_as_f32<S: serde::Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
+ serializer.serialize_f32(self.to_f32())
+ }
+
+ /// Alternate serialize adapter for serializing as a string.
+ ///
+ /// By default, [`bf16`] serializes as a newtype of [`u16`]. This is an alternate serialize
+ /// implementation that serializes as a string value. It is designed for use with
+ /// `serialize_with` serde attributes. Deserialization from string values is already supported
+ /// by the default deserialize implementation.
+ ///
+ /// # Examples
+ ///
+ /// A demonstration on how to use this adapater:
+ ///
+ /// ```
+ /// use serde::{Serialize, Deserialize};
+ /// use half::bf16;
+ ///
+ /// #[derive(Serialize, Deserialize)]
+ /// struct MyStruct {
+ /// #[serde(serialize_with = "bf16::serialize_as_string")]
+ /// value: bf16 // Will be serialized as a string instead of u16
+ /// }
+ /// ```
+ #[cfg(feature = "serde")]
+ pub fn serialize_as_string<S: serde::Serializer>(
+ &self,
+ serializer: S,
+ ) -> Result<S::Ok, S::Error> {
+ serializer.serialize_str(&self.to_string())
+ }
+
+ /// Approximate number of [`bf16`] significant digits in base 10
+ pub const DIGITS: u32 = 2;
+ /// [`bf16`]
+ /// [machine epsilon](https://en.wikipedia.org/wiki/Machine_epsilon) value
+ ///
+ /// This is the difference between 1.0 and the next largest representable number.
+ pub const EPSILON: bf16 = bf16(0x3C00u16);
+ /// [`bf16`] positive Infinity (+∞)
+ pub const INFINITY: bf16 = bf16(0x7F80u16);
+ /// Number of [`bf16`] significant digits in base 2
+ pub const MANTISSA_DIGITS: u32 = 8;
+ /// Largest finite [`bf16`] value
+ pub const MAX: bf16 = bf16(0x7F7F);
+ /// Maximum possible [`bf16`] power of 10 exponent
+ pub const MAX_10_EXP: i32 = 38;
+ /// Maximum possible [`bf16`] power of 2 exponent
+ pub const MAX_EXP: i32 = 128;
+ /// Smallest finite [`bf16`] value
+ pub const MIN: bf16 = bf16(0xFF7F);
+ /// Minimum possible normal [`bf16`] power of 10 exponent
+ pub const MIN_10_EXP: i32 = -37;
+ /// One greater than the minimum possible normal [`bf16`] power of 2 exponent
+ pub const MIN_EXP: i32 = -125;
+ /// Smallest positive normal [`bf16`] value
+ pub const MIN_POSITIVE: bf16 = bf16(0x0080u16);
+ /// [`bf16`] Not a Number (NaN)
+ pub const NAN: bf16 = bf16(0x7FC0u16);
+ /// [`bf16`] negative infinity (-∞).
+ pub const NEG_INFINITY: bf16 = bf16(0xFF80u16);
+ /// The radix or base of the internal representation of [`bf16`]
+ pub const RADIX: u32 = 2;
+
+ /// Minimum positive subnormal [`bf16`] value
+ pub const MIN_POSITIVE_SUBNORMAL: bf16 = bf16(0x0001u16);
+ /// Maximum subnormal [`bf16`] value
+ pub const MAX_SUBNORMAL: bf16 = bf16(0x007Fu16);
+
+ /// [`bf16`] 1
+ pub const ONE: bf16 = bf16(0x3F80u16);
+ /// [`bf16`] 0
+ pub const ZERO: bf16 = bf16(0x0000u16);
+ /// [`bf16`] -0
+ pub const NEG_ZERO: bf16 = bf16(0x8000u16);
+ /// [`bf16`] -1
+ pub const NEG_ONE: bf16 = bf16(0xBF80u16);
+
+ /// [`bf16`] Euler's number (ℯ)
+ pub const E: bf16 = bf16(0x402Eu16);
+ /// [`bf16`] Archimedes' constant (π)
+ pub const PI: bf16 = bf16(0x4049u16);
+ /// [`bf16`] 1/π
+ pub const FRAC_1_PI: bf16 = bf16(0x3EA3u16);
+ /// [`bf16`] 1/√2
+ pub const FRAC_1_SQRT_2: bf16 = bf16(0x3F35u16);
+ /// [`bf16`] 2/π
+ pub const FRAC_2_PI: bf16 = bf16(0x3F23u16);
+ /// [`bf16`] 2/√π
+ pub const FRAC_2_SQRT_PI: bf16 = bf16(0x3F90u16);
+ /// [`bf16`] π/2
+ pub const FRAC_PI_2: bf16 = bf16(0x3FC9u16);
+ /// [`bf16`] π/3
+ pub const FRAC_PI_3: bf16 = bf16(0x3F86u16);
+ /// [`bf16`] π/4
+ pub const FRAC_PI_4: bf16 = bf16(0x3F49u16);
+ /// [`bf16`] π/6
+ pub const FRAC_PI_6: bf16 = bf16(0x3F06u16);
+ /// [`bf16`] π/8
+ pub const FRAC_PI_8: bf16 = bf16(0x3EC9u16);
+ /// [`bf16`] 𝗅𝗇 10
+ pub const LN_10: bf16 = bf16(0x4013u16);
+ /// [`bf16`] 𝗅𝗇 2
+ pub const LN_2: bf16 = bf16(0x3F31u16);
+ /// [`bf16`] 𝗅𝗈𝗀₁₀ℯ
+ pub const LOG10_E: bf16 = bf16(0x3EDEu16);
+ /// [`bf16`] 𝗅𝗈𝗀₁₀2
+ pub const LOG10_2: bf16 = bf16(0x3E9Au16);
+ /// [`bf16`] 𝗅𝗈𝗀₂ℯ
+ pub const LOG2_E: bf16 = bf16(0x3FB9u16);
+ /// [`bf16`] 𝗅𝗈𝗀₂10
+ pub const LOG2_10: bf16 = bf16(0x4055u16);
+ /// [`bf16`] √2
+ pub const SQRT_2: bf16 = bf16(0x3FB5u16);
+}
+
+impl From<bf16> for f32 {
+ #[inline]
+ fn from(x: bf16) -> f32 {
+ x.to_f32()
+ }
+}
+
+impl From<bf16> for f64 {
+ #[inline]
+ fn from(x: bf16) -> f64 {
+ x.to_f64()
+ }
+}
+
+impl From<i8> for bf16 {
+ #[inline]
+ fn from(x: i8) -> bf16 {
+ // Convert to f32, then to bf16
+ bf16::from_f32(f32::from(x))
+ }
+}
+
+impl From<u8> for bf16 {
+ #[inline]
+ fn from(x: u8) -> bf16 {
+ // Convert to f32, then to f16
+ bf16::from_f32(f32::from(x))
+ }
+}
+
+impl PartialEq for bf16 {
+ fn eq(&self, other: &bf16) -> bool {
+ if self.is_nan() || other.is_nan() {
+ false
+ } else {
+ (self.0 == other.0) || ((self.0 | other.0) & 0x7FFFu16 == 0)
+ }
+ }
+}
+
+impl PartialOrd for bf16 {
+ fn partial_cmp(&self, other: &bf16) -> Option<Ordering> {
+ if self.is_nan() || other.is_nan() {
+ None
+ } else {
+ let neg = self.0 & 0x8000u16 != 0;
+ let other_neg = other.0 & 0x8000u16 != 0;
+ match (neg, other_neg) {
+ (false, false) => Some(self.0.cmp(&other.0)),
+ (false, true) => {
+ if (self.0 | other.0) & 0x7FFFu16 == 0 {
+ Some(Ordering::Equal)
+ } else {
+ Some(Ordering::Greater)
+ }
+ }
+ (true, false) => {
+ if (self.0 | other.0) & 0x7FFFu16 == 0 {
+ Some(Ordering::Equal)
+ } else {
+ Some(Ordering::Less)
+ }
+ }
+ (true, true) => Some(other.0.cmp(&self.0)),
+ }
+ }
+ }
+
+ fn lt(&self, other: &bf16) -> bool {
+ if self.is_nan() || other.is_nan() {
+ false
+ } else {
+ let neg = self.0 & 0x8000u16 != 0;
+ let other_neg = other.0 & 0x8000u16 != 0;
+ match (neg, other_neg) {
+ (false, false) => self.0 < other.0,
+ (false, true) => false,
+ (true, false) => (self.0 | other.0) & 0x7FFFu16 != 0,
+ (true, true) => self.0 > other.0,
+ }
+ }
+ }
+
+ fn le(&self, other: &bf16) -> bool {
+ if self.is_nan() || other.is_nan() {
+ false
+ } else {
+ let neg = self.0 & 0x8000u16 != 0;
+ let other_neg = other.0 & 0x8000u16 != 0;
+ match (neg, other_neg) {
+ (false, false) => self.0 <= other.0,
+ (false, true) => (self.0 | other.0) & 0x7FFFu16 == 0,
+ (true, false) => true,
+ (true, true) => self.0 >= other.0,
+ }
+ }
+ }
+
+ fn gt(&self, other: &bf16) -> bool {
+ if self.is_nan() || other.is_nan() {
+ false
+ } else {
+ let neg = self.0 & 0x8000u16 != 0;
+ let other_neg = other.0 & 0x8000u16 != 0;
+ match (neg, other_neg) {
+ (false, false) => self.0 > other.0,
+ (false, true) => (self.0 | other.0) & 0x7FFFu16 != 0,
+ (true, false) => false,
+ (true, true) => self.0 < other.0,
+ }
+ }
+ }
+
+ fn ge(&self, other: &bf16) -> bool {
+ if self.is_nan() || other.is_nan() {
+ false
+ } else {
+ let neg = self.0 & 0x8000u16 != 0;
+ let other_neg = other.0 & 0x8000u16 != 0;
+ match (neg, other_neg) {
+ (false, false) => self.0 >= other.0,
+ (false, true) => true,
+ (true, false) => (self.0 | other.0) & 0x7FFFu16 == 0,
+ (true, true) => self.0 <= other.0,
+ }
+ }
+ }
+}
+
+#[cfg(not(target_arch = "spirv"))]
+impl FromStr for bf16 {
+ type Err = ParseFloatError;
+ fn from_str(src: &str) -> Result<bf16, ParseFloatError> {
+ f32::from_str(src).map(bf16::from_f32)
+ }
+}
+
+#[cfg(not(target_arch = "spirv"))]
+impl Debug for bf16 {
+ fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error> {
+ write!(f, "{:?}", self.to_f32())
+ }
+}
+
+#[cfg(not(target_arch = "spirv"))]
+impl Display for bf16 {
+ fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error> {
+ write!(f, "{}", self.to_f32())
+ }
+}
+
+#[cfg(not(target_arch = "spirv"))]
+impl LowerExp for bf16 {
+ fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error> {
+ write!(f, "{:e}", self.to_f32())
+ }
+}
+
+#[cfg(not(target_arch = "spirv"))]
+impl UpperExp for bf16 {
+ fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error> {
+ write!(f, "{:E}", self.to_f32())
+ }
+}
+
+#[cfg(not(target_arch = "spirv"))]
+impl Binary for bf16 {
+ fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error> {
+ write!(f, "{:b}", self.0)
+ }
+}
+
+#[cfg(not(target_arch = "spirv"))]
+impl Octal for bf16 {
+ fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error> {
+ write!(f, "{:o}", self.0)
+ }
+}
+
+#[cfg(not(target_arch = "spirv"))]
+impl LowerHex for bf16 {
+ fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error> {
+ write!(f, "{:x}", self.0)
+ }
+}
+
+#[cfg(not(target_arch = "spirv"))]
+impl UpperHex for bf16 {
+ fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error> {
+ write!(f, "{:X}", self.0)
+ }
+}
+
+impl Neg for bf16 {
+ type Output = Self;
+
+ fn neg(self) -> Self::Output {
+ Self(self.0 ^ 0x8000)
+ }
+}
+
+impl Neg for &bf16 {
+ type Output = <bf16 as Neg>::Output;
+
+ #[inline]
+ fn neg(self) -> Self::Output {
+ Neg::neg(*self)
+ }
+}
+
+impl Add for bf16 {
+ type Output = Self;
+
+ fn add(self, rhs: Self) -> Self::Output {
+ Self::from_f32(Self::to_f32(self) + Self::to_f32(rhs))
+ }
+}
+
+impl Add<&bf16> for bf16 {
+ type Output = <bf16 as Add<bf16>>::Output;
+
+ #[inline]
+ fn add(self, rhs: &bf16) -> Self::Output {
+ self.add(*rhs)
+ }
+}
+
+impl Add<&bf16> for &bf16 {
+ type Output = <bf16 as Add<bf16>>::Output;
+
+ #[inline]
+ fn add(self, rhs: &bf16) -> Self::Output {
+ (*self).add(*rhs)
+ }
+}
+
+impl Add<bf16> for &bf16 {
+ type Output = <bf16 as Add<bf16>>::Output;
+
+ #[inline]
+ fn add(self, rhs: bf16) -> Self::Output {
+ (*self).add(rhs)
+ }
+}
+
+impl AddAssign for bf16 {
+ #[inline]
+ fn add_assign(&mut self, rhs: Self) {
+ *self = (*self).add(rhs);
+ }
+}
+
+impl AddAssign<&bf16> for bf16 {
+ #[inline]
+ fn add_assign(&mut self, rhs: &bf16) {
+ *self = (*self).add(rhs);
+ }
+}
+
+impl Sub for bf16 {
+ type Output = Self;
+
+ fn sub(self, rhs: Self) -> Self::Output {
+ Self::from_f32(Self::to_f32(self) - Self::to_f32(rhs))
+ }
+}
+
+impl Sub<&bf16> for bf16 {
+ type Output = <bf16 as Sub<bf16>>::Output;
+
+ #[inline]
+ fn sub(self, rhs: &bf16) -> Self::Output {
+ self.sub(*rhs)
+ }
+}
+
+impl Sub<&bf16> for &bf16 {
+ type Output = <bf16 as Sub<bf16>>::Output;
+
+ #[inline]
+ fn sub(self, rhs: &bf16) -> Self::Output {
+ (*self).sub(*rhs)
+ }
+}
+
+impl Sub<bf16> for &bf16 {
+ type Output = <bf16 as Sub<bf16>>::Output;
+
+ #[inline]
+ fn sub(self, rhs: bf16) -> Self::Output {
+ (*self).sub(rhs)
+ }
+}
+
+impl SubAssign for bf16 {
+ #[inline]
+ fn sub_assign(&mut self, rhs: Self) {
+ *self = (*self).sub(rhs);
+ }
+}
+
+impl SubAssign<&bf16> for bf16 {
+ #[inline]
+ fn sub_assign(&mut self, rhs: &bf16) {
+ *self = (*self).sub(rhs);
+ }
+}
+
+impl Mul for bf16 {
+ type Output = Self;
+
+ fn mul(self, rhs: Self) -> Self::Output {
+ Self::from_f32(Self::to_f32(self) * Self::to_f32(rhs))
+ }
+}
+
+impl Mul<&bf16> for bf16 {
+ type Output = <bf16 as Mul<bf16>>::Output;
+
+ #[inline]
+ fn mul(self, rhs: &bf16) -> Self::Output {
+ self.mul(*rhs)
+ }
+}
+
+impl Mul<&bf16> for &bf16 {
+ type Output = <bf16 as Mul<bf16>>::Output;
+
+ #[inline]
+ fn mul(self, rhs: &bf16) -> Self::Output {
+ (*self).mul(*rhs)
+ }
+}
+
+impl Mul<bf16> for &bf16 {
+ type Output = <bf16 as Mul<bf16>>::Output;
+
+ #[inline]
+ fn mul(self, rhs: bf16) -> Self::Output {
+ (*self).mul(rhs)
+ }
+}
+
+impl MulAssign for bf16 {
+ #[inline]
+ fn mul_assign(&mut self, rhs: Self) {
+ *self = (*self).mul(rhs);
+ }
+}
+
+impl MulAssign<&bf16> for bf16 {
+ #[inline]
+ fn mul_assign(&mut self, rhs: &bf16) {
+ *self = (*self).mul(rhs);
+ }
+}
+
+impl Div for bf16 {
+ type Output = Self;
+
+ fn div(self, rhs: Self) -> Self::Output {
+ Self::from_f32(Self::to_f32(self) / Self::to_f32(rhs))
+ }
+}
+
+impl Div<&bf16> for bf16 {
+ type Output = <bf16 as Div<bf16>>::Output;
+
+ #[inline]
+ fn div(self, rhs: &bf16) -> Self::Output {
+ self.div(*rhs)
+ }
+}
+
+impl Div<&bf16> for &bf16 {
+ type Output = <bf16 as Div<bf16>>::Output;
+
+ #[inline]
+ fn div(self, rhs: &bf16) -> Self::Output {
+ (*self).div(*rhs)
+ }
+}
+
+impl Div<bf16> for &bf16 {
+ type Output = <bf16 as Div<bf16>>::Output;
+
+ #[inline]
+ fn div(self, rhs: bf16) -> Self::Output {
+ (*self).div(rhs)
+ }
+}
+
+impl DivAssign for bf16 {
+ #[inline]
+ fn div_assign(&mut self, rhs: Self) {
+ *self = (*self).div(rhs);
+ }
+}
+
+impl DivAssign<&bf16> for bf16 {
+ #[inline]
+ fn div_assign(&mut self, rhs: &bf16) {
+ *self = (*self).div(rhs);
+ }
+}
+
+impl Rem for bf16 {
+ type Output = Self;
+
+ fn rem(self, rhs: Self) -> Self::Output {
+ Self::from_f32(Self::to_f32(self) % Self::to_f32(rhs))
+ }
+}
+
+impl Rem<&bf16> for bf16 {
+ type Output = <bf16 as Rem<bf16>>::Output;
+
+ #[inline]
+ fn rem(self, rhs: &bf16) -> Self::Output {
+ self.rem(*rhs)
+ }
+}
+
+impl Rem<&bf16> for &bf16 {
+ type Output = <bf16 as Rem<bf16>>::Output;
+
+ #[inline]
+ fn rem(self, rhs: &bf16) -> Self::Output {
+ (*self).rem(*rhs)
+ }
+}
+
+impl Rem<bf16> for &bf16 {
+ type Output = <bf16 as Rem<bf16>>::Output;
+
+ #[inline]
+ fn rem(self, rhs: bf16) -> Self::Output {
+ (*self).rem(rhs)
+ }
+}
+
+impl RemAssign for bf16 {
+ #[inline]
+ fn rem_assign(&mut self, rhs: Self) {
+ *self = (*self).rem(rhs);
+ }
+}
+
+impl RemAssign<&bf16> for bf16 {
+ #[inline]
+ fn rem_assign(&mut self, rhs: &bf16) {
+ *self = (*self).rem(rhs);
+ }
+}
+
+impl Product for bf16 {
+ #[inline]
+ fn product<I: Iterator<Item = Self>>(iter: I) -> Self {
+ bf16::from_f32(iter.map(|f| f.to_f32()).product())
+ }
+}
+
+impl<'a> Product<&'a bf16> for bf16 {
+ #[inline]
+ fn product<I: Iterator<Item = &'a bf16>>(iter: I) -> Self {
+ bf16::from_f32(iter.map(|f| f.to_f32()).product())
+ }
+}
+
+impl Sum for bf16 {
+ #[inline]
+ fn sum<I: Iterator<Item = Self>>(iter: I) -> Self {
+ bf16::from_f32(iter.map(|f| f.to_f32()).sum())
+ }
+}
+
+impl<'a> Sum<&'a bf16> for bf16 {
+ #[inline]
+ fn sum<I: Iterator<Item = &'a bf16>>(iter: I) -> Self {
+ bf16::from_f32(iter.map(|f| f.to_f32()).product())
+ }
+}
+
+#[cfg(feature = "serde")]
+struct Visitor;
+
+#[cfg(feature = "serde")]
+impl<'de> Deserialize<'de> for bf16 {
+ fn deserialize<D>(deserializer: D) -> Result<bf16, D::Error>
+ where
+ D: serde::de::Deserializer<'de>,
+ {
+ deserializer.deserialize_newtype_struct("bf16", Visitor)
+ }
+}
+
+#[cfg(feature = "serde")]
+impl<'de> serde::de::Visitor<'de> for Visitor {
+ type Value = bf16;
+
+ fn expecting(&self, formatter: &mut alloc::fmt::Formatter) -> alloc::fmt::Result {
+ write!(formatter, "tuple struct bf16")
+ }
+
+ fn visit_newtype_struct<D>(self, deserializer: D) -> Result<Self::Value, D::Error>
+ where
+ D: serde::Deserializer<'de>,
+ {
+ Ok(bf16(<u16 as Deserialize>::deserialize(deserializer)?))
+ }
+
+ fn visit_str<E>(self, v: &str) -> Result<Self::Value, E>
+ where
+ E: serde::de::Error,
+ {
+ v.parse().map_err(|_| {
+ serde::de::Error::invalid_value(serde::de::Unexpected::Str(v), &"a float string")
+ })
+ }
+
+ fn visit_f32<E>(self, v: f32) -> Result<Self::Value, E>
+ where
+ E: serde::de::Error,
+ {
+ Ok(bf16::from_f32(v))
+ }
+
+ fn visit_f64<E>(self, v: f64) -> Result<Self::Value, E>
+ where
+ E: serde::de::Error,
+ {
+ Ok(bf16::from_f64(v))
+ }
+}
+
+#[allow(
+ clippy::cognitive_complexity,
+ clippy::float_cmp,
+ clippy::neg_cmp_op_on_partial_ord
+)]
+#[cfg(test)]
+mod test {
+ use super::*;
+ use core::cmp::Ordering;
+ #[cfg(feature = "num-traits")]
+ use num_traits::{AsPrimitive, FromPrimitive, ToPrimitive};
+ use quickcheck_macros::quickcheck;
+
+ #[cfg(feature = "num-traits")]
+ #[test]
+ fn as_primitive() {
+ let two = bf16::from_f32(2.0);
+ assert_eq!(<i32 as AsPrimitive<bf16>>::as_(2), two);
+ assert_eq!(<bf16 as AsPrimitive<i32>>::as_(two), 2);
+
+ assert_eq!(<f32 as AsPrimitive<bf16>>::as_(2.0), two);
+ assert_eq!(<bf16 as AsPrimitive<f32>>::as_(two), 2.0);
+
+ assert_eq!(<f64 as AsPrimitive<bf16>>::as_(2.0), two);
+ assert_eq!(<bf16 as AsPrimitive<f64>>::as_(two), 2.0);
+ }
+
+ #[cfg(feature = "num-traits")]
+ #[test]
+ fn to_primitive() {
+ let two = bf16::from_f32(2.0);
+ assert_eq!(ToPrimitive::to_i32(&two).unwrap(), 2i32);
+ assert_eq!(ToPrimitive::to_f32(&two).unwrap(), 2.0f32);
+ assert_eq!(ToPrimitive::to_f64(&two).unwrap(), 2.0f64);
+ }
+
+ #[cfg(feature = "num-traits")]
+ #[test]
+ fn from_primitive() {
+ let two = bf16::from_f32(2.0);
+ assert_eq!(<bf16 as FromPrimitive>::from_i32(2).unwrap(), two);
+ assert_eq!(<bf16 as FromPrimitive>::from_f32(2.0).unwrap(), two);
+ assert_eq!(<bf16 as FromPrimitive>::from_f64(2.0).unwrap(), two);
+ }
+
+ #[test]
+ fn test_bf16_consts_from_f32() {
+ let one = bf16::from_f32(1.0);
+ let zero = bf16::from_f32(0.0);
+ let neg_zero = bf16::from_f32(-0.0);
+ let neg_one = bf16::from_f32(-1.0);
+ let inf = bf16::from_f32(core::f32::INFINITY);
+ let neg_inf = bf16::from_f32(core::f32::NEG_INFINITY);
+ let nan = bf16::from_f32(core::f32::NAN);
+
+ assert_eq!(bf16::ONE, one);
+ assert_eq!(bf16::ZERO, zero);
+ assert!(zero.is_sign_positive());
+ assert_eq!(bf16::NEG_ZERO, neg_zero);
+ assert!(neg_zero.is_sign_negative());
+ assert_eq!(bf16::NEG_ONE, neg_one);
+ assert!(neg_one.is_sign_negative());
+ assert_eq!(bf16::INFINITY, inf);
+ assert_eq!(bf16::NEG_INFINITY, neg_inf);
+ assert!(nan.is_nan());
+ assert!(bf16::NAN.is_nan());
+
+ let e = bf16::from_f32(core::f32::consts::E);
+ let pi = bf16::from_f32(core::f32::consts::PI);
+ let frac_1_pi = bf16::from_f32(core::f32::consts::FRAC_1_PI);
+ let frac_1_sqrt_2 = bf16::from_f32(core::f32::consts::FRAC_1_SQRT_2);
+ let frac_2_pi = bf16::from_f32(core::f32::consts::FRAC_2_PI);
+ let frac_2_sqrt_pi = bf16::from_f32(core::f32::consts::FRAC_2_SQRT_PI);
+ let frac_pi_2 = bf16::from_f32(core::f32::consts::FRAC_PI_2);
+ let frac_pi_3 = bf16::from_f32(core::f32::consts::FRAC_PI_3);
+ let frac_pi_4 = bf16::from_f32(core::f32::consts::FRAC_PI_4);
+ let frac_pi_6 = bf16::from_f32(core::f32::consts::FRAC_PI_6);
+ let frac_pi_8 = bf16::from_f32(core::f32::consts::FRAC_PI_8);
+ let ln_10 = bf16::from_f32(core::f32::consts::LN_10);
+ let ln_2 = bf16::from_f32(core::f32::consts::LN_2);
+ let log10_e = bf16::from_f32(core::f32::consts::LOG10_E);
+ // core::f32::consts::LOG10_2 requires rustc 1.43.0
+ let log10_2 = bf16::from_f32(2f32.log10());
+ let log2_e = bf16::from_f32(core::f32::consts::LOG2_E);
+ // core::f32::consts::LOG2_10 requires rustc 1.43.0
+ let log2_10 = bf16::from_f32(10f32.log2());
+ let sqrt_2 = bf16::from_f32(core::f32::consts::SQRT_2);
+
+ assert_eq!(bf16::E, e);
+ assert_eq!(bf16::PI, pi);
+ assert_eq!(bf16::FRAC_1_PI, frac_1_pi);
+ assert_eq!(bf16::FRAC_1_SQRT_2, frac_1_sqrt_2);
+ assert_eq!(bf16::FRAC_2_PI, frac_2_pi);
+ assert_eq!(bf16::FRAC_2_SQRT_PI, frac_2_sqrt_pi);
+ assert_eq!(bf16::FRAC_PI_2, frac_pi_2);
+ assert_eq!(bf16::FRAC_PI_3, frac_pi_3);
+ assert_eq!(bf16::FRAC_PI_4, frac_pi_4);
+ assert_eq!(bf16::FRAC_PI_6, frac_pi_6);
+ assert_eq!(bf16::FRAC_PI_8, frac_pi_8);
+ assert_eq!(bf16::LN_10, ln_10);
+ assert_eq!(bf16::LN_2, ln_2);
+ assert_eq!(bf16::LOG10_E, log10_e);
+ assert_eq!(bf16::LOG10_2, log10_2);
+ assert_eq!(bf16::LOG2_E, log2_e);
+ assert_eq!(bf16::LOG2_10, log2_10);
+ assert_eq!(bf16::SQRT_2, sqrt_2);
+ }
+
+ #[test]
+ fn test_bf16_consts_from_f64() {
+ let one = bf16::from_f64(1.0);
+ let zero = bf16::from_f64(0.0);
+ let neg_zero = bf16::from_f64(-0.0);
+ let inf = bf16::from_f64(core::f64::INFINITY);
+ let neg_inf = bf16::from_f64(core::f64::NEG_INFINITY);
+ let nan = bf16::from_f64(core::f64::NAN);
+
+ assert_eq!(bf16::ONE, one);
+ assert_eq!(bf16::ZERO, zero);
+ assert_eq!(bf16::NEG_ZERO, neg_zero);
+ assert_eq!(bf16::INFINITY, inf);
+ assert_eq!(bf16::NEG_INFINITY, neg_inf);
+ assert!(nan.is_nan());
+ assert!(bf16::NAN.is_nan());
+
+ let e = bf16::from_f64(core::f64::consts::E);
+ let pi = bf16::from_f64(core::f64::consts::PI);
+ let frac_1_pi = bf16::from_f64(core::f64::consts::FRAC_1_PI);
+ let frac_1_sqrt_2 = bf16::from_f64(core::f64::consts::FRAC_1_SQRT_2);
+ let frac_2_pi = bf16::from_f64(core::f64::consts::FRAC_2_PI);
+ let frac_2_sqrt_pi = bf16::from_f64(core::f64::consts::FRAC_2_SQRT_PI);
+ let frac_pi_2 = bf16::from_f64(core::f64::consts::FRAC_PI_2);
+ let frac_pi_3 = bf16::from_f64(core::f64::consts::FRAC_PI_3);
+ let frac_pi_4 = bf16::from_f64(core::f64::consts::FRAC_PI_4);
+ let frac_pi_6 = bf16::from_f64(core::f64::consts::FRAC_PI_6);
+ let frac_pi_8 = bf16::from_f64(core::f64::consts::FRAC_PI_8);
+ let ln_10 = bf16::from_f64(core::f64::consts::LN_10);
+ let ln_2 = bf16::from_f64(core::f64::consts::LN_2);
+ let log10_e = bf16::from_f64(core::f64::consts::LOG10_E);
+ // core::f64::consts::LOG10_2 requires rustc 1.43.0
+ let log10_2 = bf16::from_f64(2f64.log10());
+ let log2_e = bf16::from_f64(core::f64::consts::LOG2_E);
+ // core::f64::consts::LOG2_10 requires rustc 1.43.0
+ let log2_10 = bf16::from_f64(10f64.log2());
+ let sqrt_2 = bf16::from_f64(core::f64::consts::SQRT_2);
+
+ assert_eq!(bf16::E, e);
+ assert_eq!(bf16::PI, pi);
+ assert_eq!(bf16::FRAC_1_PI, frac_1_pi);
+ assert_eq!(bf16::FRAC_1_SQRT_2, frac_1_sqrt_2);
+ assert_eq!(bf16::FRAC_2_PI, frac_2_pi);
+ assert_eq!(bf16::FRAC_2_SQRT_PI, frac_2_sqrt_pi);
+ assert_eq!(bf16::FRAC_PI_2, frac_pi_2);
+ assert_eq!(bf16::FRAC_PI_3, frac_pi_3);
+ assert_eq!(bf16::FRAC_PI_4, frac_pi_4);
+ assert_eq!(bf16::FRAC_PI_6, frac_pi_6);
+ assert_eq!(bf16::FRAC_PI_8, frac_pi_8);
+ assert_eq!(bf16::LN_10, ln_10);
+ assert_eq!(bf16::LN_2, ln_2);
+ assert_eq!(bf16::LOG10_E, log10_e);
+ assert_eq!(bf16::LOG10_2, log10_2);
+ assert_eq!(bf16::LOG2_E, log2_e);
+ assert_eq!(bf16::LOG2_10, log2_10);
+ assert_eq!(bf16::SQRT_2, sqrt_2);
+ }
+
+ #[test]
+ fn test_nan_conversion_to_smaller() {
+ let nan64 = f64::from_bits(0x7FF0_0000_0000_0001u64);
+ let neg_nan64 = f64::from_bits(0xFFF0_0000_0000_0001u64);
+ let nan32 = f32::from_bits(0x7F80_0001u32);
+ let neg_nan32 = f32::from_bits(0xFF80_0001u32);
+ let nan32_from_64 = nan64 as f32;
+ let neg_nan32_from_64 = neg_nan64 as f32;
+ let nan16_from_64 = bf16::from_f64(nan64);
+ let neg_nan16_from_64 = bf16::from_f64(neg_nan64);
+ let nan16_from_32 = bf16::from_f32(nan32);
+ let neg_nan16_from_32 = bf16::from_f32(neg_nan32);
+
+ assert!(nan64.is_nan() && nan64.is_sign_positive());
+ assert!(neg_nan64.is_nan() && neg_nan64.is_sign_negative());
+ assert!(nan32.is_nan() && nan32.is_sign_positive());
+ assert!(neg_nan32.is_nan() && neg_nan32.is_sign_negative());
+ assert!(nan32_from_64.is_nan() && nan32_from_64.is_sign_positive());
+ assert!(neg_nan32_from_64.is_nan() && neg_nan32_from_64.is_sign_negative());
+ assert!(nan16_from_64.is_nan() && nan16_from_64.is_sign_positive());
+ assert!(neg_nan16_from_64.is_nan() && neg_nan16_from_64.is_sign_negative());
+ assert!(nan16_from_32.is_nan() && nan16_from_32.is_sign_positive());
+ assert!(neg_nan16_from_32.is_nan() && neg_nan16_from_32.is_sign_negative());
+ }
+
+ #[test]
+ fn test_nan_conversion_to_larger() {
+ let nan16 = bf16::from_bits(0x7F81u16);
+ let neg_nan16 = bf16::from_bits(0xFF81u16);
+ let nan32 = f32::from_bits(0x7F80_0001u32);
+ let neg_nan32 = f32::from_bits(0xFF80_0001u32);
+ let nan32_from_16 = f32::from(nan16);
+ let neg_nan32_from_16 = f32::from(neg_nan16);
+ let nan64_from_16 = f64::from(nan16);
+ let neg_nan64_from_16 = f64::from(neg_nan16);
+ let nan64_from_32 = f64::from(nan32);
+ let neg_nan64_from_32 = f64::from(neg_nan32);
+
+ assert!(nan16.is_nan() && nan16.is_sign_positive());
+ assert!(neg_nan16.is_nan() && neg_nan16.is_sign_negative());
+ assert!(nan32.is_nan() && nan32.is_sign_positive());
+ assert!(neg_nan32.is_nan() && neg_nan32.is_sign_negative());
+ assert!(nan32_from_16.is_nan() && nan32_from_16.is_sign_positive());
+ assert!(neg_nan32_from_16.is_nan() && neg_nan32_from_16.is_sign_negative());
+ assert!(nan64_from_16.is_nan() && nan64_from_16.is_sign_positive());
+ assert!(neg_nan64_from_16.is_nan() && neg_nan64_from_16.is_sign_negative());
+ assert!(nan64_from_32.is_nan() && nan64_from_32.is_sign_positive());
+ assert!(neg_nan64_from_32.is_nan() && neg_nan64_from_32.is_sign_negative());
+ }
+
+ #[test]
+ fn test_bf16_to_f32() {
+ let f = bf16::from_f32(7.0);
+ assert_eq!(f.to_f32(), 7.0f32);
+
+ // 7.1 is NOT exactly representable in 16-bit, it's rounded
+ let f = bf16::from_f32(7.1);
+ let diff = (f.to_f32() - 7.1f32).abs();
+ // diff must be <= 4 * EPSILON, as 7 has two more significant bits than 1
+ assert!(diff <= 4.0 * bf16::EPSILON.to_f32());
+
+ let tiny32 = f32::from_bits(0x0001_0000u32);
+ assert_eq!(bf16::from_bits(0x0001).to_f32(), tiny32);
+ assert_eq!(bf16::from_bits(0x0005).to_f32(), 5.0 * tiny32);
+
+ assert_eq!(bf16::from_bits(0x0001), bf16::from_f32(tiny32));
+ assert_eq!(bf16::from_bits(0x0005), bf16::from_f32(5.0 * tiny32));
+ }
+
+ #[test]
+ fn test_bf16_to_f64() {
+ let f = bf16::from_f64(7.0);
+ assert_eq!(f.to_f64(), 7.0f64);
+
+ // 7.1 is NOT exactly representable in 16-bit, it's rounded
+ let f = bf16::from_f64(7.1);
+ let diff = (f.to_f64() - 7.1f64).abs();
+ // diff must be <= 4 * EPSILON, as 7 has two more significant bits than 1
+ assert!(diff <= 4.0 * bf16::EPSILON.to_f64());
+
+ let tiny64 = 2.0f64.powi(-133);
+ assert_eq!(bf16::from_bits(0x0001).to_f64(), tiny64);
+ assert_eq!(bf16::from_bits(0x0005).to_f64(), 5.0 * tiny64);
+
+ assert_eq!(bf16::from_bits(0x0001), bf16::from_f64(tiny64));
+ assert_eq!(bf16::from_bits(0x0005), bf16::from_f64(5.0 * tiny64));
+ }
+
+ #[test]
+ fn test_comparisons() {
+ let zero = bf16::from_f64(0.0);
+ let one = bf16::from_f64(1.0);
+ let neg_zero = bf16::from_f64(-0.0);
+ let neg_one = bf16::from_f64(-1.0);
+
+ assert_eq!(zero.partial_cmp(&neg_zero), Some(Ordering::Equal));
+ assert_eq!(neg_zero.partial_cmp(&zero), Some(Ordering::Equal));
+ assert!(zero == neg_zero);
+ assert!(neg_zero == zero);
+ assert!(!(zero != neg_zero));
+ assert!(!(neg_zero != zero));
+ assert!(!(zero < neg_zero));
+ assert!(!(neg_zero < zero));
+ assert!(zero <= neg_zero);
+ assert!(neg_zero <= zero);
+ assert!(!(zero > neg_zero));
+ assert!(!(neg_zero > zero));
+ assert!(zero >= neg_zero);
+ assert!(neg_zero >= zero);
+
+ assert_eq!(one.partial_cmp(&neg_zero), Some(Ordering::Greater));
+ assert_eq!(neg_zero.partial_cmp(&one), Some(Ordering::Less));
+ assert!(!(one == neg_zero));
+ assert!(!(neg_zero == one));
+ assert!(one != neg_zero);
+ assert!(neg_zero != one);
+ assert!(!(one < neg_zero));
+ assert!(neg_zero < one);
+ assert!(!(one <= neg_zero));
+ assert!(neg_zero <= one);
+ assert!(one > neg_zero);
+ assert!(!(neg_zero > one));
+ assert!(one >= neg_zero);
+ assert!(!(neg_zero >= one));
+
+ assert_eq!(one.partial_cmp(&neg_one), Some(Ordering::Greater));
+ assert_eq!(neg_one.partial_cmp(&one), Some(Ordering::Less));
+ assert!(!(one == neg_one));
+ assert!(!(neg_one == one));
+ assert!(one != neg_one);
+ assert!(neg_one != one);
+ assert!(!(one < neg_one));
+ assert!(neg_one < one);
+ assert!(!(one <= neg_one));
+ assert!(neg_one <= one);
+ assert!(one > neg_one);
+ assert!(!(neg_one > one));
+ assert!(one >= neg_one);
+ assert!(!(neg_one >= one));
+ }
+
+ #[test]
+ #[allow(clippy::erasing_op, clippy::identity_op)]
+ fn round_to_even_f32() {
+ // smallest positive subnormal = 0b0.0000_001 * 2^-126 = 2^-133
+ let min_sub = bf16::from_bits(1);
+ let min_sub_f = (-133f32).exp2();
+ assert_eq!(bf16::from_f32(min_sub_f).to_bits(), min_sub.to_bits());
+ assert_eq!(f32::from(min_sub).to_bits(), min_sub_f.to_bits());
+
+ // 0.0000000_011111 rounded to 0.0000000 (< tie, no rounding)
+ // 0.0000000_100000 rounded to 0.0000000 (tie and even, remains at even)
+ // 0.0000000_100001 rounded to 0.0000001 (> tie, rounds up)
+ assert_eq!(
+ bf16::from_f32(min_sub_f * 0.49).to_bits(),
+ min_sub.to_bits() * 0
+ );
+ assert_eq!(
+ bf16::from_f32(min_sub_f * 0.50).to_bits(),
+ min_sub.to_bits() * 0
+ );
+ assert_eq!(
+ bf16::from_f32(min_sub_f * 0.51).to_bits(),
+ min_sub.to_bits() * 1
+ );
+
+ // 0.0000001_011111 rounded to 0.0000001 (< tie, no rounding)
+ // 0.0000001_100000 rounded to 0.0000010 (tie and odd, rounds up to even)
+ // 0.0000001_100001 rounded to 0.0000010 (> tie, rounds up)
+ assert_eq!(
+ bf16::from_f32(min_sub_f * 1.49).to_bits(),
+ min_sub.to_bits() * 1
+ );
+ assert_eq!(
+ bf16::from_f32(min_sub_f * 1.50).to_bits(),
+ min_sub.to_bits() * 2
+ );
+ assert_eq!(
+ bf16::from_f32(min_sub_f * 1.51).to_bits(),
+ min_sub.to_bits() * 2
+ );
+
+ // 0.0000010_011111 rounded to 0.0000010 (< tie, no rounding)
+ // 0.0000010_100000 rounded to 0.0000010 (tie and even, remains at even)
+ // 0.0000010_100001 rounded to 0.0000011 (> tie, rounds up)
+ assert_eq!(
+ bf16::from_f32(min_sub_f * 2.49).to_bits(),
+ min_sub.to_bits() * 2
+ );
+ assert_eq!(
+ bf16::from_f32(min_sub_f * 2.50).to_bits(),
+ min_sub.to_bits() * 2
+ );
+ assert_eq!(
+ bf16::from_f32(min_sub_f * 2.51).to_bits(),
+ min_sub.to_bits() * 3
+ );
+
+ assert_eq!(
+ bf16::from_f32(250.49f32).to_bits(),
+ bf16::from_f32(250.0).to_bits()
+ );
+ assert_eq!(
+ bf16::from_f32(250.50f32).to_bits(),
+ bf16::from_f32(250.0).to_bits()
+ );
+ assert_eq!(
+ bf16::from_f32(250.51f32).to_bits(),
+ bf16::from_f32(251.0).to_bits()
+ );
+ assert_eq!(
+ bf16::from_f32(251.49f32).to_bits(),
+ bf16::from_f32(251.0).to_bits()
+ );
+ assert_eq!(
+ bf16::from_f32(251.50f32).to_bits(),
+ bf16::from_f32(252.0).to_bits()
+ );
+ assert_eq!(
+ bf16::from_f32(251.51f32).to_bits(),
+ bf16::from_f32(252.0).to_bits()
+ );
+ assert_eq!(
+ bf16::from_f32(252.49f32).to_bits(),
+ bf16::from_f32(252.0).to_bits()
+ );
+ assert_eq!(
+ bf16::from_f32(252.50f32).to_bits(),
+ bf16::from_f32(252.0).to_bits()
+ );
+ assert_eq!(
+ bf16::from_f32(252.51f32).to_bits(),
+ bf16::from_f32(253.0).to_bits()
+ );
+ }
+
+ #[test]
+ #[allow(clippy::erasing_op, clippy::identity_op)]
+ fn round_to_even_f64() {
+ // smallest positive subnormal = 0b0.0000_001 * 2^-126 = 2^-133
+ let min_sub = bf16::from_bits(1);
+ let min_sub_f = (-133f64).exp2();
+ assert_eq!(bf16::from_f64(min_sub_f).to_bits(), min_sub.to_bits());
+ assert_eq!(f64::from(min_sub).to_bits(), min_sub_f.to_bits());
+
+ // 0.0000000_011111 rounded to 0.0000000 (< tie, no rounding)
+ // 0.0000000_100000 rounded to 0.0000000 (tie and even, remains at even)
+ // 0.0000000_100001 rounded to 0.0000001 (> tie, rounds up)
+ assert_eq!(
+ bf16::from_f64(min_sub_f * 0.49).to_bits(),
+ min_sub.to_bits() * 0
+ );
+ assert_eq!(
+ bf16::from_f64(min_sub_f * 0.50).to_bits(),
+ min_sub.to_bits() * 0
+ );
+ assert_eq!(
+ bf16::from_f64(min_sub_f * 0.51).to_bits(),
+ min_sub.to_bits() * 1
+ );
+
+ // 0.0000001_011111 rounded to 0.0000001 (< tie, no rounding)
+ // 0.0000001_100000 rounded to 0.0000010 (tie and odd, rounds up to even)
+ // 0.0000001_100001 rounded to 0.0000010 (> tie, rounds up)
+ assert_eq!(
+ bf16::from_f64(min_sub_f * 1.49).to_bits(),
+ min_sub.to_bits() * 1
+ );
+ assert_eq!(
+ bf16::from_f64(min_sub_f * 1.50).to_bits(),
+ min_sub.to_bits() * 2
+ );
+ assert_eq!(
+ bf16::from_f64(min_sub_f * 1.51).to_bits(),
+ min_sub.to_bits() * 2
+ );
+
+ // 0.0000010_011111 rounded to 0.0000010 (< tie, no rounding)
+ // 0.0000010_100000 rounded to 0.0000010 (tie and even, remains at even)
+ // 0.0000010_100001 rounded to 0.0000011 (> tie, rounds up)
+ assert_eq!(
+ bf16::from_f64(min_sub_f * 2.49).to_bits(),
+ min_sub.to_bits() * 2
+ );
+ assert_eq!(
+ bf16::from_f64(min_sub_f * 2.50).to_bits(),
+ min_sub.to_bits() * 2
+ );
+ assert_eq!(
+ bf16::from_f64(min_sub_f * 2.51).to_bits(),
+ min_sub.to_bits() * 3
+ );
+
+ assert_eq!(
+ bf16::from_f64(250.49f64).to_bits(),
+ bf16::from_f64(250.0).to_bits()
+ );
+ assert_eq!(
+ bf16::from_f64(250.50f64).to_bits(),
+ bf16::from_f64(250.0).to_bits()
+ );
+ assert_eq!(
+ bf16::from_f64(250.51f64).to_bits(),
+ bf16::from_f64(251.0).to_bits()
+ );
+ assert_eq!(
+ bf16::from_f64(251.49f64).to_bits(),
+ bf16::from_f64(251.0).to_bits()
+ );
+ assert_eq!(
+ bf16::from_f64(251.50f64).to_bits(),
+ bf16::from_f64(252.0).to_bits()
+ );
+ assert_eq!(
+ bf16::from_f64(251.51f64).to_bits(),
+ bf16::from_f64(252.0).to_bits()
+ );
+ assert_eq!(
+ bf16::from_f64(252.49f64).to_bits(),
+ bf16::from_f64(252.0).to_bits()
+ );
+ assert_eq!(
+ bf16::from_f64(252.50f64).to_bits(),
+ bf16::from_f64(252.0).to_bits()
+ );
+ assert_eq!(
+ bf16::from_f64(252.51f64).to_bits(),
+ bf16::from_f64(253.0).to_bits()
+ );
+ }
+
+ impl quickcheck::Arbitrary for bf16 {
+ fn arbitrary(g: &mut quickcheck::Gen) -> Self {
+ bf16(u16::arbitrary(g))
+ }
+ }
+
+ #[quickcheck]
+ fn qc_roundtrip_bf16_f32_is_identity(f: bf16) -> bool {
+ let roundtrip = bf16::from_f32(f.to_f32());
+ if f.is_nan() {
+ roundtrip.is_nan() && f.is_sign_negative() == roundtrip.is_sign_negative()
+ } else {
+ f.0 == roundtrip.0
+ }
+ }
+
+ #[quickcheck]
+ fn qc_roundtrip_bf16_f64_is_identity(f: bf16) -> bool {
+ let roundtrip = bf16::from_f64(f.to_f64());
+ if f.is_nan() {
+ roundtrip.is_nan() && f.is_sign_negative() == roundtrip.is_sign_negative()
+ } else {
+ f.0 == roundtrip.0
+ }
+ }
+}
--- /dev/null
+use crate::leading_zeros::leading_zeros_u16;
+use core::mem;
+
+#[inline]
+pub(crate) const fn f32_to_bf16(value: f32) -> u16 {
+ // TODO: Replace mem::transmute with to_bits() once to_bits is const-stabilized
+ // Convert to raw bytes
+ let x: u32 = unsafe { mem::transmute(value) };
+
+ // check for NaN
+ if x & 0x7FFF_FFFFu32 > 0x7F80_0000u32 {
+ // Keep high part of current mantissa but also set most significiant mantissa bit
+ return ((x >> 16) | 0x0040u32) as u16;
+ }
+
+ // round and shift
+ let round_bit = 0x0000_8000u32;
+ if (x & round_bit) != 0 && (x & (3 * round_bit - 1)) != 0 {
+ (x >> 16) as u16 + 1
+ } else {
+ (x >> 16) as u16
+ }
+}
+
+#[inline]
+pub(crate) const fn f64_to_bf16(value: f64) -> u16 {
+ // TODO: Replace mem::transmute with to_bits() once to_bits is const-stabilized
+ // Convert to raw bytes, truncating the last 32-bits of mantissa; that precision will always
+ // be lost on half-precision.
+ let val: u64 = unsafe { mem::transmute(value) };
+ let x = (val >> 32) as u32;
+
+ // Extract IEEE754 components
+ let sign = x & 0x8000_0000u32;
+ let exp = x & 0x7FF0_0000u32;
+ let man = x & 0x000F_FFFFu32;
+
+ // Check for all exponent bits being set, which is Infinity or NaN
+ if exp == 0x7FF0_0000u32 {
+ // Set mantissa MSB for NaN (and also keep shifted mantissa bits).
+ // We also have to check the last 32 bits.
+ let nan_bit = if man == 0 && (val as u32 == 0) {
+ 0
+ } else {
+ 0x0040u32
+ };
+ return ((sign >> 16) | 0x7F80u32 | nan_bit | (man >> 13)) as u16;
+ }
+
+ // The number is normalized, start assembling half precision version
+ let half_sign = sign >> 16;
+ // Unbias the exponent, then bias for bfloat16 precision
+ let unbiased_exp = ((exp >> 20) as i64) - 1023;
+ let half_exp = unbiased_exp + 127;
+
+ // Check for exponent overflow, return +infinity
+ if half_exp >= 0xFF {
+ return (half_sign | 0x7F80u32) as u16;
+ }
+
+ // Check for underflow
+ if half_exp <= 0 {
+ // Check mantissa for what we can do
+ if 7 - half_exp > 21 {
+ // No rounding possibility, so this is a full underflow, return signed zero
+ return half_sign as u16;
+ }
+ // Don't forget about hidden leading mantissa bit when assembling mantissa
+ let man = man | 0x0010_0000u32;
+ let mut half_man = man >> (14 - half_exp);
+ // Check for rounding
+ let round_bit = 1 << (13 - half_exp);
+ if (man & round_bit) != 0 && (man & (3 * round_bit - 1)) != 0 {
+ half_man += 1;
+ }
+ // No exponent for subnormals
+ return (half_sign | half_man) as u16;
+ }
+
+ // Rebias the exponent
+ let half_exp = (half_exp as u32) << 7;
+ let half_man = man >> 13;
+ // Check for rounding
+ let round_bit = 0x0000_1000u32;
+ if (man & round_bit) != 0 && (man & (3 * round_bit - 1)) != 0 {
+ // Round it
+ ((half_sign | half_exp | half_man) + 1) as u16
+ } else {
+ (half_sign | half_exp | half_man) as u16
+ }
+}
+
+#[inline]
+pub(crate) const fn bf16_to_f32(i: u16) -> f32 {
+ // TODO: Replace mem::transmute with from_bits() once from_bits is const-stabilized
+ // If NaN, keep current mantissa but also set most significiant mantissa bit
+ if i & 0x7FFFu16 > 0x7F80u16 {
+ unsafe { mem::transmute((i as u32 | 0x0040u32) << 16) }
+ } else {
+ unsafe { mem::transmute((i as u32) << 16) }
+ }
+}
+
+#[inline]
+pub(crate) const fn bf16_to_f64(i: u16) -> f64 {
+ // TODO: Replace mem::transmute with from_bits() once from_bits is const-stabilized
+ // Check for signed zero
+ if i & 0x7FFFu16 == 0 {
+ return unsafe { mem::transmute((i as u64) << 48) };
+ }
+
+ let half_sign = (i & 0x8000u16) as u64;
+ let half_exp = (i & 0x7F80u16) as u64;
+ let half_man = (i & 0x007Fu16) as u64;
+
+ // Check for an infinity or NaN when all exponent bits set
+ if half_exp == 0x7F80u64 {
+ // Check for signed infinity if mantissa is zero
+ if half_man == 0 {
+ return unsafe { mem::transmute((half_sign << 48) | 0x7FF0_0000_0000_0000u64) };
+ } else {
+ // NaN, keep current mantissa but also set most significiant mantissa bit
+ return unsafe {
+ mem::transmute((half_sign << 48) | 0x7FF8_0000_0000_0000u64 | (half_man << 45))
+ };
+ }
+ }
+
+ // Calculate double-precision components with adjusted exponent
+ let sign = half_sign << 48;
+ // Unbias exponent
+ let unbiased_exp = ((half_exp as i64) >> 7) - 127;
+
+ // Check for subnormals, which will be normalized by adjusting exponent
+ if half_exp == 0 {
+ // Calculate how much to adjust the exponent by
+ let e = leading_zeros_u16(half_man as u16) - 9;
+
+ // Rebias and adjust exponent
+ let exp = ((1023 - 127 - e) as u64) << 52;
+ let man = (half_man << (46 + e)) & 0xF_FFFF_FFFF_FFFFu64;
+ return unsafe { mem::transmute(sign | exp | man) };
+ }
+ // Rebias exponent for a normalized normal
+ let exp = ((unbiased_exp + 1023) as u64) << 52;
+ let man = (half_man & 0x007Fu64) << 45;
+ unsafe { mem::transmute(sign | exp | man) }
+}
--- /dev/null
+#[cfg(feature = "bytemuck")]
+use bytemuck::{Pod, Zeroable};
+use core::{
+ cmp::Ordering,
+ iter::{Product, Sum},
+ num::FpCategory,
+ ops::{Add, AddAssign, Div, DivAssign, Mul, MulAssign, Neg, Rem, RemAssign, Sub, SubAssign},
+};
+#[cfg(not(target_arch = "spirv"))]
+use core::{
+ fmt::{
+ Binary, Debug, Display, Error, Formatter, LowerExp, LowerHex, Octal, UpperExp, UpperHex,
+ },
+ num::ParseFloatError,
+ str::FromStr,
+};
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
+#[cfg(feature = "zerocopy")]
+use zerocopy::{AsBytes, FromBytes};
+
+pub(crate) mod convert;
+
+/// A 16-bit floating point type implementing the IEEE 754-2008 standard [`binary16`] a.k.a `half`
+/// format.
+///
+/// This 16-bit floating point type is intended for efficient storage where the full range and
+/// precision of a larger floating point value is not required. Because [`f16`] is primarily for
+/// efficient storage, floating point operations such as addition, multiplication, etc. are not
+/// implemented. Operations should be performed with [`f32`] or higher-precision types and converted
+/// to/from [`f16`] as necessary.
+///
+/// [`binary16`]: https://en.wikipedia.org/wiki/Half-precision_floating-point_format
+#[allow(non_camel_case_types)]
+#[derive(Clone, Copy, Default)]
+#[repr(transparent)]
+#[cfg_attr(feature = "serde", derive(Serialize))]
+#[cfg_attr(feature = "bytemuck", derive(Zeroable, Pod))]
+#[cfg_attr(feature = "zerocopy", derive(AsBytes, FromBytes))]
+pub struct f16(u16);
+
+impl f16 {
+ /// Constructs a 16-bit floating point value from the raw bits.
+ #[inline]
+ #[must_use]
+ pub const fn from_bits(bits: u16) -> f16 {
+ f16(bits)
+ }
+
+ /// Constructs a 16-bit floating point value from a 32-bit floating point value.
+ ///
+ /// If the 32-bit value is to large to fit in 16-bits, ±∞ will result. NaN values are
+ /// preserved. 32-bit subnormal values are too tiny to be represented in 16-bits and result in
+ /// ±0. Exponents that underflow the minimum 16-bit exponent will result in 16-bit subnormals
+ /// or ±0. All other values are truncated and rounded to the nearest representable 16-bit
+ /// value.
+ #[inline]
+ #[must_use]
+ pub fn from_f32(value: f32) -> f16 {
+ f16(convert::f32_to_f16(value))
+ }
+
+ /// Constructs a 16-bit floating point value from a 32-bit floating point value.
+ ///
+ /// This function is identical to [`from_f32`][Self::from_f32] except it never uses hardware
+ /// intrinsics, which allows it to be `const`. [`from_f32`][Self::from_f32] should be preferred
+ /// in any non-`const` context.
+ ///
+ /// If the 32-bit value is to large to fit in 16-bits, ±∞ will result. NaN values are
+ /// preserved. 32-bit subnormal values are too tiny to be represented in 16-bits and result in
+ /// ±0. Exponents that underflow the minimum 16-bit exponent will result in 16-bit subnormals
+ /// or ±0. All other values are truncated and rounded to the nearest representable 16-bit
+ /// value.
+ #[inline]
+ #[must_use]
+ pub const fn from_f32_const(value: f32) -> f16 {
+ f16(convert::f32_to_f16_fallback(value))
+ }
+
+ /// Constructs a 16-bit floating point value from a 64-bit floating point value.
+ ///
+ /// If the 64-bit value is to large to fit in 16-bits, ±∞ will result. NaN values are
+ /// preserved. 64-bit subnormal values are too tiny to be represented in 16-bits and result in
+ /// ±0. Exponents that underflow the minimum 16-bit exponent will result in 16-bit subnormals
+ /// or ±0. All other values are truncated and rounded to the nearest representable 16-bit
+ /// value.
+ #[inline]
+ #[must_use]
+ pub fn from_f64(value: f64) -> f16 {
+ f16(convert::f64_to_f16(value))
+ }
+
+ /// Constructs a 16-bit floating point value from a 64-bit floating point value.
+ ///
+ /// This function is identical to [`from_f64`][Self::from_f64] except it never uses hardware
+ /// intrinsics, which allows it to be `const`. [`from_f64`][Self::from_f64] should be preferred
+ /// in any non-`const` context.
+ ///
+ /// If the 64-bit value is to large to fit in 16-bits, ±∞ will result. NaN values are
+ /// preserved. 64-bit subnormal values are too tiny to be represented in 16-bits and result in
+ /// ±0. Exponents that underflow the minimum 16-bit exponent will result in 16-bit subnormals
+ /// or ±0. All other values are truncated and rounded to the nearest representable 16-bit
+ /// value.
+ #[inline]
+ #[must_use]
+ pub const fn from_f64_const(value: f64) -> f16 {
+ f16(convert::f64_to_f16_fallback(value))
+ }
+
+ /// Converts a [`f16`] into the underlying bit representation.
+ #[inline]
+ #[must_use]
+ pub const fn to_bits(self) -> u16 {
+ self.0
+ }
+
+ /// Returns the memory representation of the underlying bit representation as a byte array in
+ /// little-endian byte order.
+ ///
+ /// # Examples
+ ///
+ /// ```rust
+ /// # use half::prelude::*;
+ /// let bytes = f16::from_f32(12.5).to_le_bytes();
+ /// assert_eq!(bytes, [0x40, 0x4A]);
+ /// ```
+ #[inline]
+ #[must_use]
+ pub const fn to_le_bytes(self) -> [u8; 2] {
+ self.0.to_le_bytes()
+ }
+
+ /// Returns the memory representation of the underlying bit representation as a byte array in
+ /// big-endian (network) byte order.
+ ///
+ /// # Examples
+ ///
+ /// ```rust
+ /// # use half::prelude::*;
+ /// let bytes = f16::from_f32(12.5).to_be_bytes();
+ /// assert_eq!(bytes, [0x4A, 0x40]);
+ /// ```
+ #[inline]
+ #[must_use]
+ pub const fn to_be_bytes(self) -> [u8; 2] {
+ self.0.to_be_bytes()
+ }
+
+ /// Returns the memory representation of the underlying bit representation as a byte array in
+ /// native byte order.
+ ///
+ /// As the target platform's native endianness is used, portable code should use
+ /// [`to_be_bytes`][Self::to_be_bytes] or [`to_le_bytes`][Self::to_le_bytes], as appropriate,
+ /// instead.
+ ///
+ /// # Examples
+ ///
+ /// ```rust
+ /// # use half::prelude::*;
+ /// let bytes = f16::from_f32(12.5).to_ne_bytes();
+ /// assert_eq!(bytes, if cfg!(target_endian = "big") {
+ /// [0x4A, 0x40]
+ /// } else {
+ /// [0x40, 0x4A]
+ /// });
+ /// ```
+ #[inline]
+ #[must_use]
+ pub const fn to_ne_bytes(self) -> [u8; 2] {
+ self.0.to_ne_bytes()
+ }
+
+ /// Creates a floating point value from its representation as a byte array in little endian.
+ ///
+ /// # Examples
+ ///
+ /// ```rust
+ /// # use half::prelude::*;
+ /// let value = f16::from_le_bytes([0x40, 0x4A]);
+ /// assert_eq!(value, f16::from_f32(12.5));
+ /// ```
+ #[inline]
+ #[must_use]
+ pub const fn from_le_bytes(bytes: [u8; 2]) -> f16 {
+ f16::from_bits(u16::from_le_bytes(bytes))
+ }
+
+ /// Creates a floating point value from its representation as a byte array in big endian.
+ ///
+ /// # Examples
+ ///
+ /// ```rust
+ /// # use half::prelude::*;
+ /// let value = f16::from_be_bytes([0x4A, 0x40]);
+ /// assert_eq!(value, f16::from_f32(12.5));
+ /// ```
+ #[inline]
+ #[must_use]
+ pub const fn from_be_bytes(bytes: [u8; 2]) -> f16 {
+ f16::from_bits(u16::from_be_bytes(bytes))
+ }
+
+ /// Creates a floating point value from its representation as a byte array in native endian.
+ ///
+ /// As the target platform's native endianness is used, portable code likely wants to use
+ /// [`from_be_bytes`][Self::from_be_bytes] or [`from_le_bytes`][Self::from_le_bytes], as
+ /// appropriate instead.
+ ///
+ /// # Examples
+ ///
+ /// ```rust
+ /// # use half::prelude::*;
+ /// let value = f16::from_ne_bytes(if cfg!(target_endian = "big") {
+ /// [0x4A, 0x40]
+ /// } else {
+ /// [0x40, 0x4A]
+ /// });
+ /// assert_eq!(value, f16::from_f32(12.5));
+ /// ```
+ #[inline]
+ #[must_use]
+ pub const fn from_ne_bytes(bytes: [u8; 2]) -> f16 {
+ f16::from_bits(u16::from_ne_bytes(bytes))
+ }
+
+ /// Converts a [`f16`] value into a `f32` value.
+ ///
+ /// This conversion is lossless as all 16-bit floating point values can be represented exactly
+ /// in 32-bit floating point.
+ #[inline]
+ #[must_use]
+ pub fn to_f32(self) -> f32 {
+ convert::f16_to_f32(self.0)
+ }
+
+ /// Converts a [`f16`] value into a `f32` value.
+ ///
+ /// This function is identical to [`to_f32`][Self::to_f32] except it never uses hardware
+ /// intrinsics, which allows it to be `const`. [`to_f32`][Self::to_f32] should be preferred
+ /// in any non-`const` context.
+ ///
+ /// This conversion is lossless as all 16-bit floating point values can be represented exactly
+ /// in 32-bit floating point.
+ #[inline]
+ #[must_use]
+ pub const fn to_f32_const(self) -> f32 {
+ convert::f16_to_f32_fallback(self.0)
+ }
+
+ /// Converts a [`f16`] value into a `f64` value.
+ ///
+ /// This conversion is lossless as all 16-bit floating point values can be represented exactly
+ /// in 64-bit floating point.
+ #[inline]
+ #[must_use]
+ pub fn to_f64(self) -> f64 {
+ convert::f16_to_f64(self.0)
+ }
+
+ /// Converts a [`f16`] value into a `f64` value.
+ ///
+ /// This function is identical to [`to_f64`][Self::to_f64] except it never uses hardware
+ /// intrinsics, which allows it to be `const`. [`to_f64`][Self::to_f64] should be preferred
+ /// in any non-`const` context.
+ ///
+ /// This conversion is lossless as all 16-bit floating point values can be represented exactly
+ /// in 64-bit floating point.
+ #[inline]
+ #[must_use]
+ pub const fn to_f64_const(self) -> f64 {
+ convert::f16_to_f64_fallback(self.0)
+ }
+
+ /// Returns `true` if this value is `NaN` and `false` otherwise.
+ ///
+ /// # Examples
+ ///
+ /// ```rust
+ /// # use half::prelude::*;
+ ///
+ /// let nan = f16::NAN;
+ /// let f = f16::from_f32(7.0_f32);
+ ///
+ /// assert!(nan.is_nan());
+ /// assert!(!f.is_nan());
+ /// ```
+ #[inline]
+ #[must_use]
+ pub const fn is_nan(self) -> bool {
+ self.0 & 0x7FFFu16 > 0x7C00u16
+ }
+
+ /// Returns `true` if this value is ±∞ and `false`.
+ /// otherwise.
+ ///
+ /// # Examples
+ ///
+ /// ```rust
+ /// # use half::prelude::*;
+ ///
+ /// let f = f16::from_f32(7.0f32);
+ /// let inf = f16::INFINITY;
+ /// let neg_inf = f16::NEG_INFINITY;
+ /// let nan = f16::NAN;
+ ///
+ /// assert!(!f.is_infinite());
+ /// assert!(!nan.is_infinite());
+ ///
+ /// assert!(inf.is_infinite());
+ /// assert!(neg_inf.is_infinite());
+ /// ```
+ #[inline]
+ #[must_use]
+ pub const fn is_infinite(self) -> bool {
+ self.0 & 0x7FFFu16 == 0x7C00u16
+ }
+
+ /// Returns `true` if this number is neither infinite nor `NaN`.
+ ///
+ /// # Examples
+ ///
+ /// ```rust
+ /// # use half::prelude::*;
+ ///
+ /// let f = f16::from_f32(7.0f32);
+ /// let inf = f16::INFINITY;
+ /// let neg_inf = f16::NEG_INFINITY;
+ /// let nan = f16::NAN;
+ ///
+ /// assert!(f.is_finite());
+ ///
+ /// assert!(!nan.is_finite());
+ /// assert!(!inf.is_finite());
+ /// assert!(!neg_inf.is_finite());
+ /// ```
+ #[inline]
+ #[must_use]
+ pub const fn is_finite(self) -> bool {
+ self.0 & 0x7C00u16 != 0x7C00u16
+ }
+
+ /// Returns `true` if the number is neither zero, infinite, subnormal, or `NaN`.
+ ///
+ /// # Examples
+ ///
+ /// ```rust
+ /// # use half::prelude::*;
+ ///
+ /// let min = f16::MIN_POSITIVE;
+ /// let max = f16::MAX;
+ /// let lower_than_min = f16::from_f32(1.0e-10_f32);
+ /// let zero = f16::from_f32(0.0_f32);
+ ///
+ /// assert!(min.is_normal());
+ /// assert!(max.is_normal());
+ ///
+ /// assert!(!zero.is_normal());
+ /// assert!(!f16::NAN.is_normal());
+ /// assert!(!f16::INFINITY.is_normal());
+ /// // Values between `0` and `min` are Subnormal.
+ /// assert!(!lower_than_min.is_normal());
+ /// ```
+ #[inline]
+ #[must_use]
+ pub const fn is_normal(self) -> bool {
+ let exp = self.0 & 0x7C00u16;
+ exp != 0x7C00u16 && exp != 0
+ }
+
+ /// Returns the floating point category of the number.
+ ///
+ /// If only one property is going to be tested, it is generally faster to use the specific
+ /// predicate instead.
+ ///
+ /// # Examples
+ ///
+ /// ```rust
+ /// use std::num::FpCategory;
+ /// # use half::prelude::*;
+ ///
+ /// let num = f16::from_f32(12.4_f32);
+ /// let inf = f16::INFINITY;
+ ///
+ /// assert_eq!(num.classify(), FpCategory::Normal);
+ /// assert_eq!(inf.classify(), FpCategory::Infinite);
+ /// ```
+ #[must_use]
+ pub const fn classify(self) -> FpCategory {
+ let exp = self.0 & 0x7C00u16;
+ let man = self.0 & 0x03FFu16;
+ match (exp, man) {
+ (0, 0) => FpCategory::Zero,
+ (0, _) => FpCategory::Subnormal,
+ (0x7C00u16, 0) => FpCategory::Infinite,
+ (0x7C00u16, _) => FpCategory::Nan,
+ _ => FpCategory::Normal,
+ }
+ }
+
+ /// Returns a number that represents the sign of `self`.
+ ///
+ /// * `1.0` if the number is positive, `+0.0` or [`INFINITY`][f16::INFINITY]
+ /// * `-1.0` if the number is negative, `-0.0` or [`NEG_INFINITY`][f16::NEG_INFINITY]
+ /// * [`NAN`][f16::NAN] if the number is `NaN`
+ ///
+ /// # Examples
+ ///
+ /// ```rust
+ /// # use half::prelude::*;
+ ///
+ /// let f = f16::from_f32(3.5_f32);
+ ///
+ /// assert_eq!(f.signum(), f16::from_f32(1.0));
+ /// assert_eq!(f16::NEG_INFINITY.signum(), f16::from_f32(-1.0));
+ ///
+ /// assert!(f16::NAN.signum().is_nan());
+ /// ```
+ #[must_use]
+ pub const fn signum(self) -> f16 {
+ if self.is_nan() {
+ self
+ } else if self.0 & 0x8000u16 != 0 {
+ Self::NEG_ONE
+ } else {
+ Self::ONE
+ }
+ }
+
+ /// Returns `true` if and only if `self` has a positive sign, including `+0.0`, `NaNs` with a
+ /// positive sign bit and +∞.
+ ///
+ /// # Examples
+ ///
+ /// ```rust
+ /// # use half::prelude::*;
+ ///
+ /// let nan = f16::NAN;
+ /// let f = f16::from_f32(7.0_f32);
+ /// let g = f16::from_f32(-7.0_f32);
+ ///
+ /// assert!(f.is_sign_positive());
+ /// assert!(!g.is_sign_positive());
+ /// // `NaN` can be either positive or negative
+ /// assert!(nan.is_sign_positive() != nan.is_sign_negative());
+ /// ```
+ #[inline]
+ #[must_use]
+ pub const fn is_sign_positive(self) -> bool {
+ self.0 & 0x8000u16 == 0
+ }
+
+ /// Returns `true` if and only if `self` has a negative sign, including `-0.0`, `NaNs` with a
+ /// negative sign bit and −∞.
+ ///
+ /// # Examples
+ ///
+ /// ```rust
+ /// # use half::prelude::*;
+ ///
+ /// let nan = f16::NAN;
+ /// let f = f16::from_f32(7.0f32);
+ /// let g = f16::from_f32(-7.0f32);
+ ///
+ /// assert!(!f.is_sign_negative());
+ /// assert!(g.is_sign_negative());
+ /// // `NaN` can be either positive or negative
+ /// assert!(nan.is_sign_positive() != nan.is_sign_negative());
+ /// ```
+ #[inline]
+ #[must_use]
+ pub const fn is_sign_negative(self) -> bool {
+ self.0 & 0x8000u16 != 0
+ }
+
+ /// Returns a number composed of the magnitude of `self` and the sign of `sign`.
+ ///
+ /// Equal to `self` if the sign of `self` and `sign` are the same, otherwise equal to `-self`.
+ /// If `self` is NaN, then NaN with the sign of `sign` is returned.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// # use half::prelude::*;
+ /// let f = f16::from_f32(3.5);
+ ///
+ /// assert_eq!(f.copysign(f16::from_f32(0.42)), f16::from_f32(3.5));
+ /// assert_eq!(f.copysign(f16::from_f32(-0.42)), f16::from_f32(-3.5));
+ /// assert_eq!((-f).copysign(f16::from_f32(0.42)), f16::from_f32(3.5));
+ /// assert_eq!((-f).copysign(f16::from_f32(-0.42)), f16::from_f32(-3.5));
+ ///
+ /// assert!(f16::NAN.copysign(f16::from_f32(1.0)).is_nan());
+ /// ```
+ #[inline]
+ #[must_use]
+ pub const fn copysign(self, sign: f16) -> f16 {
+ f16((sign.0 & 0x8000u16) | (self.0 & 0x7FFFu16))
+ }
+
+ /// Returns the maximum of the two numbers.
+ ///
+ /// If one of the arguments is NaN, then the other argument is returned.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// # use half::prelude::*;
+ /// let x = f16::from_f32(1.0);
+ /// let y = f16::from_f32(2.0);
+ ///
+ /// assert_eq!(x.max(y), y);
+ /// ```
+ #[inline]
+ #[must_use]
+ pub fn max(self, other: f16) -> f16 {
+ if other > self && !other.is_nan() {
+ other
+ } else {
+ self
+ }
+ }
+
+ /// Returns the minimum of the two numbers.
+ ///
+ /// If one of the arguments is NaN, then the other argument is returned.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// # use half::prelude::*;
+ /// let x = f16::from_f32(1.0);
+ /// let y = f16::from_f32(2.0);
+ ///
+ /// assert_eq!(x.min(y), x);
+ /// ```
+ #[inline]
+ #[must_use]
+ pub fn min(self, other: f16) -> f16 {
+ if other < self && !other.is_nan() {
+ other
+ } else {
+ self
+ }
+ }
+
+ /// Restrict a value to a certain interval unless it is NaN.
+ ///
+ /// Returns `max` if `self` is greater than `max`, and `min` if `self` is less than `min`.
+ /// Otherwise this returns `self`.
+ ///
+ /// Note that this function returns NaN if the initial value was NaN as well.
+ ///
+ /// # Panics
+ /// Panics if `min > max`, `min` is NaN, or `max` is NaN.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// # use half::prelude::*;
+ /// assert!(f16::from_f32(-3.0).clamp(f16::from_f32(-2.0), f16::from_f32(1.0)) == f16::from_f32(-2.0));
+ /// assert!(f16::from_f32(0.0).clamp(f16::from_f32(-2.0), f16::from_f32(1.0)) == f16::from_f32(0.0));
+ /// assert!(f16::from_f32(2.0).clamp(f16::from_f32(-2.0), f16::from_f32(1.0)) == f16::from_f32(1.0));
+ /// assert!(f16::NAN.clamp(f16::from_f32(-2.0), f16::from_f32(1.0)).is_nan());
+ /// ```
+ #[inline]
+ #[must_use]
+ pub fn clamp(self, min: f16, max: f16) -> f16 {
+ assert!(min <= max);
+ let mut x = self;
+ if x < min {
+ x = min;
+ }
+ if x > max {
+ x = max;
+ }
+ x
+ }
+
+ /// Returns the ordering between `self` and `other`.
+ ///
+ /// Unlike the standard partial comparison between floating point numbers,
+ /// this comparison always produces an ordering in accordance to
+ /// the `totalOrder` predicate as defined in the IEEE 754 (2008 revision)
+ /// floating point standard. The values are ordered in the following sequence:
+ ///
+ /// - negative quiet NaN
+ /// - negative signaling NaN
+ /// - negative infinity
+ /// - negative numbers
+ /// - negative subnormal numbers
+ /// - negative zero
+ /// - positive zero
+ /// - positive subnormal numbers
+ /// - positive numbers
+ /// - positive infinity
+ /// - positive signaling NaN
+ /// - positive quiet NaN.
+ ///
+ /// The ordering established by this function does not always agree with the
+ /// [`PartialOrd`] and [`PartialEq`] implementations of `f16`. For example,
+ /// they consider negative and positive zero equal, while `total_cmp`
+ /// doesn't.
+ ///
+ /// The interpretation of the signaling NaN bit follows the definition in
+ /// the IEEE 754 standard, which may not match the interpretation by some of
+ /// the older, non-conformant (e.g. MIPS) hardware implementations.
+ ///
+ /// # Examples
+ /// ```
+ /// # use half::f16;
+ /// let mut v: Vec<f16> = vec![];
+ /// v.push(f16::ONE);
+ /// v.push(f16::INFINITY);
+ /// v.push(f16::NEG_INFINITY);
+ /// v.push(f16::NAN);
+ /// v.push(f16::MAX_SUBNORMAL);
+ /// v.push(-f16::MAX_SUBNORMAL);
+ /// v.push(f16::ZERO);
+ /// v.push(f16::NEG_ZERO);
+ /// v.push(f16::NEG_ONE);
+ /// v.push(f16::MIN_POSITIVE);
+ ///
+ /// v.sort_by(|a, b| a.total_cmp(&b));
+ ///
+ /// assert!(v
+ /// .into_iter()
+ /// .zip(
+ /// [
+ /// f16::NEG_INFINITY,
+ /// f16::NEG_ONE,
+ /// -f16::MAX_SUBNORMAL,
+ /// f16::NEG_ZERO,
+ /// f16::ZERO,
+ /// f16::MAX_SUBNORMAL,
+ /// f16::MIN_POSITIVE,
+ /// f16::ONE,
+ /// f16::INFINITY,
+ /// f16::NAN
+ /// ]
+ /// .iter()
+ /// )
+ /// .all(|(a, b)| a.to_bits() == b.to_bits()));
+ /// ```
+ // Implementation based on: https://doc.rust-lang.org/std/primitive.f32.html#method.total_cmp
+ #[inline]
+ #[must_use]
+ pub fn total_cmp(&self, other: &Self) -> Ordering {
+ let mut left = self.to_bits() as i16;
+ let mut right = other.to_bits() as i16;
+ left ^= (((left >> 15) as u16) >> 1) as i16;
+ right ^= (((right >> 15) as u16) >> 1) as i16;
+ left.cmp(&right)
+ }
+
+ /// Alternate serialize adapter for serializing as a float.
+ ///
+ /// By default, [`f16`] serializes as a newtype of [`u16`]. This is an alternate serialize
+ /// implementation that serializes as an [`f32`] value. It is designed for use with
+ /// `serialize_with` serde attributes. Deserialization from `f32` values is already supported by
+ /// the default deserialize implementation.
+ ///
+ /// # Examples
+ ///
+ /// A demonstration on how to use this adapater:
+ ///
+ /// ```
+ /// use serde::{Serialize, Deserialize};
+ /// use half::f16;
+ ///
+ /// #[derive(Serialize, Deserialize)]
+ /// struct MyStruct {
+ /// #[serde(serialize_with = "f16::serialize_as_f32")]
+ /// value: f16 // Will be serialized as f32 instead of u16
+ /// }
+ /// ```
+ #[cfg(feature = "serde")]
+ pub fn serialize_as_f32<S: serde::Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
+ serializer.serialize_f32(self.to_f32())
+ }
+
+ /// Alternate serialize adapter for serializing as a string.
+ ///
+ /// By default, [`f16`] serializes as a newtype of [`u16`]. This is an alternate serialize
+ /// implementation that serializes as a string value. It is designed for use with
+ /// `serialize_with` serde attributes. Deserialization from string values is already supported
+ /// by the default deserialize implementation.
+ ///
+ /// # Examples
+ ///
+ /// A demonstration on how to use this adapater:
+ ///
+ /// ```
+ /// use serde::{Serialize, Deserialize};
+ /// use half::f16;
+ ///
+ /// #[derive(Serialize, Deserialize)]
+ /// struct MyStruct {
+ /// #[serde(serialize_with = "f16::serialize_as_string")]
+ /// value: f16 // Will be serialized as a string instead of u16
+ /// }
+ /// ```
+ #[cfg(feature = "serde")]
+ pub fn serialize_as_string<S: serde::Serializer>(
+ &self,
+ serializer: S,
+ ) -> Result<S::Ok, S::Error> {
+ serializer.serialize_str(&self.to_string())
+ }
+
+ /// Approximate number of [`f16`] significant digits in base 10
+ pub const DIGITS: u32 = 3;
+ /// [`f16`]
+ /// [machine epsilon](https://en.wikipedia.org/wiki/Machine_epsilon) value
+ ///
+ /// This is the difference between 1.0 and the next largest representable number.
+ pub const EPSILON: f16 = f16(0x1400u16);
+ /// [`f16`] positive Infinity (+∞)
+ pub const INFINITY: f16 = f16(0x7C00u16);
+ /// Number of [`f16`] significant digits in base 2
+ pub const MANTISSA_DIGITS: u32 = 11;
+ /// Largest finite [`f16`] value
+ pub const MAX: f16 = f16(0x7BFF);
+ /// Maximum possible [`f16`] power of 10 exponent
+ pub const MAX_10_EXP: i32 = 4;
+ /// Maximum possible [`f16`] power of 2 exponent
+ pub const MAX_EXP: i32 = 16;
+ /// Smallest finite [`f16`] value
+ pub const MIN: f16 = f16(0xFBFF);
+ /// Minimum possible normal [`f16`] power of 10 exponent
+ pub const MIN_10_EXP: i32 = -4;
+ /// One greater than the minimum possible normal [`f16`] power of 2 exponent
+ pub const MIN_EXP: i32 = -13;
+ /// Smallest positive normal [`f16`] value
+ pub const MIN_POSITIVE: f16 = f16(0x0400u16);
+ /// [`f16`] Not a Number (NaN)
+ pub const NAN: f16 = f16(0x7E00u16);
+ /// [`f16`] negative infinity (-∞)
+ pub const NEG_INFINITY: f16 = f16(0xFC00u16);
+ /// The radix or base of the internal representation of [`f16`]
+ pub const RADIX: u32 = 2;
+
+ /// Minimum positive subnormal [`f16`] value
+ pub const MIN_POSITIVE_SUBNORMAL: f16 = f16(0x0001u16);
+ /// Maximum subnormal [`f16`] value
+ pub const MAX_SUBNORMAL: f16 = f16(0x03FFu16);
+
+ /// [`f16`] 1
+ pub const ONE: f16 = f16(0x3C00u16);
+ /// [`f16`] 0
+ pub const ZERO: f16 = f16(0x0000u16);
+ /// [`f16`] -0
+ pub const NEG_ZERO: f16 = f16(0x8000u16);
+ /// [`f16`] -1
+ pub const NEG_ONE: f16 = f16(0xBC00u16);
+
+ /// [`f16`] Euler's number (ℯ)
+ pub const E: f16 = f16(0x4170u16);
+ /// [`f16`] Archimedes' constant (π)
+ pub const PI: f16 = f16(0x4248u16);
+ /// [`f16`] 1/π
+ pub const FRAC_1_PI: f16 = f16(0x3518u16);
+ /// [`f16`] 1/√2
+ pub const FRAC_1_SQRT_2: f16 = f16(0x39A8u16);
+ /// [`f16`] 2/π
+ pub const FRAC_2_PI: f16 = f16(0x3918u16);
+ /// [`f16`] 2/√π
+ pub const FRAC_2_SQRT_PI: f16 = f16(0x3C83u16);
+ /// [`f16`] π/2
+ pub const FRAC_PI_2: f16 = f16(0x3E48u16);
+ /// [`f16`] π/3
+ pub const FRAC_PI_3: f16 = f16(0x3C30u16);
+ /// [`f16`] π/4
+ pub const FRAC_PI_4: f16 = f16(0x3A48u16);
+ /// [`f16`] π/6
+ pub const FRAC_PI_6: f16 = f16(0x3830u16);
+ /// [`f16`] π/8
+ pub const FRAC_PI_8: f16 = f16(0x3648u16);
+ /// [`f16`] 𝗅𝗇 10
+ pub const LN_10: f16 = f16(0x409Bu16);
+ /// [`f16`] 𝗅𝗇 2
+ pub const LN_2: f16 = f16(0x398Cu16);
+ /// [`f16`] 𝗅𝗈𝗀₁₀ℯ
+ pub const LOG10_E: f16 = f16(0x36F3u16);
+ /// [`f16`] 𝗅𝗈𝗀₁₀2
+ pub const LOG10_2: f16 = f16(0x34D1u16);
+ /// [`f16`] 𝗅𝗈𝗀₂ℯ
+ pub const LOG2_E: f16 = f16(0x3DC5u16);
+ /// [`f16`] 𝗅𝗈𝗀₂10
+ pub const LOG2_10: f16 = f16(0x42A5u16);
+ /// [`f16`] √2
+ pub const SQRT_2: f16 = f16(0x3DA8u16);
+}
+
+impl From<f16> for f32 {
+ #[inline]
+ fn from(x: f16) -> f32 {
+ x.to_f32()
+ }
+}
+
+impl From<f16> for f64 {
+ #[inline]
+ fn from(x: f16) -> f64 {
+ x.to_f64()
+ }
+}
+
+impl From<i8> for f16 {
+ #[inline]
+ fn from(x: i8) -> f16 {
+ // Convert to f32, then to f16
+ f16::from_f32(f32::from(x))
+ }
+}
+
+impl From<u8> for f16 {
+ #[inline]
+ fn from(x: u8) -> f16 {
+ // Convert to f32, then to f16
+ f16::from_f32(f32::from(x))
+ }
+}
+
+impl PartialEq for f16 {
+ fn eq(&self, other: &f16) -> bool {
+ if self.is_nan() || other.is_nan() {
+ false
+ } else {
+ (self.0 == other.0) || ((self.0 | other.0) & 0x7FFFu16 == 0)
+ }
+ }
+}
+
+impl PartialOrd for f16 {
+ fn partial_cmp(&self, other: &f16) -> Option<Ordering> {
+ if self.is_nan() || other.is_nan() {
+ None
+ } else {
+ let neg = self.0 & 0x8000u16 != 0;
+ let other_neg = other.0 & 0x8000u16 != 0;
+ match (neg, other_neg) {
+ (false, false) => Some(self.0.cmp(&other.0)),
+ (false, true) => {
+ if (self.0 | other.0) & 0x7FFFu16 == 0 {
+ Some(Ordering::Equal)
+ } else {
+ Some(Ordering::Greater)
+ }
+ }
+ (true, false) => {
+ if (self.0 | other.0) & 0x7FFFu16 == 0 {
+ Some(Ordering::Equal)
+ } else {
+ Some(Ordering::Less)
+ }
+ }
+ (true, true) => Some(other.0.cmp(&self.0)),
+ }
+ }
+ }
+
+ fn lt(&self, other: &f16) -> bool {
+ if self.is_nan() || other.is_nan() {
+ false
+ } else {
+ let neg = self.0 & 0x8000u16 != 0;
+ let other_neg = other.0 & 0x8000u16 != 0;
+ match (neg, other_neg) {
+ (false, false) => self.0 < other.0,
+ (false, true) => false,
+ (true, false) => (self.0 | other.0) & 0x7FFFu16 != 0,
+ (true, true) => self.0 > other.0,
+ }
+ }
+ }
+
+ fn le(&self, other: &f16) -> bool {
+ if self.is_nan() || other.is_nan() {
+ false
+ } else {
+ let neg = self.0 & 0x8000u16 != 0;
+ let other_neg = other.0 & 0x8000u16 != 0;
+ match (neg, other_neg) {
+ (false, false) => self.0 <= other.0,
+ (false, true) => (self.0 | other.0) & 0x7FFFu16 == 0,
+ (true, false) => true,
+ (true, true) => self.0 >= other.0,
+ }
+ }
+ }
+
+ fn gt(&self, other: &f16) -> bool {
+ if self.is_nan() || other.is_nan() {
+ false
+ } else {
+ let neg = self.0 & 0x8000u16 != 0;
+ let other_neg = other.0 & 0x8000u16 != 0;
+ match (neg, other_neg) {
+ (false, false) => self.0 > other.0,
+ (false, true) => (self.0 | other.0) & 0x7FFFu16 != 0,
+ (true, false) => false,
+ (true, true) => self.0 < other.0,
+ }
+ }
+ }
+
+ fn ge(&self, other: &f16) -> bool {
+ if self.is_nan() || other.is_nan() {
+ false
+ } else {
+ let neg = self.0 & 0x8000u16 != 0;
+ let other_neg = other.0 & 0x8000u16 != 0;
+ match (neg, other_neg) {
+ (false, false) => self.0 >= other.0,
+ (false, true) => true,
+ (true, false) => (self.0 | other.0) & 0x7FFFu16 == 0,
+ (true, true) => self.0 <= other.0,
+ }
+ }
+ }
+}
+
+#[cfg(not(target_arch = "spirv"))]
+impl FromStr for f16 {
+ type Err = ParseFloatError;
+ fn from_str(src: &str) -> Result<f16, ParseFloatError> {
+ f32::from_str(src).map(f16::from_f32)
+ }
+}
+
+#[cfg(not(target_arch = "spirv"))]
+impl Debug for f16 {
+ fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error> {
+ write!(f, "{:?}", self.to_f32())
+ }
+}
+
+#[cfg(not(target_arch = "spirv"))]
+impl Display for f16 {
+ fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error> {
+ write!(f, "{}", self.to_f32())
+ }
+}
+
+#[cfg(not(target_arch = "spirv"))]
+impl LowerExp for f16 {
+ fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error> {
+ write!(f, "{:e}", self.to_f32())
+ }
+}
+
+#[cfg(not(target_arch = "spirv"))]
+impl UpperExp for f16 {
+ fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error> {
+ write!(f, "{:E}", self.to_f32())
+ }
+}
+
+#[cfg(not(target_arch = "spirv"))]
+impl Binary for f16 {
+ fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error> {
+ write!(f, "{:b}", self.0)
+ }
+}
+
+#[cfg(not(target_arch = "spirv"))]
+impl Octal for f16 {
+ fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error> {
+ write!(f, "{:o}", self.0)
+ }
+}
+
+#[cfg(not(target_arch = "spirv"))]
+impl LowerHex for f16 {
+ fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error> {
+ write!(f, "{:x}", self.0)
+ }
+}
+
+#[cfg(not(target_arch = "spirv"))]
+impl UpperHex for f16 {
+ fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error> {
+ write!(f, "{:X}", self.0)
+ }
+}
+
+impl Neg for f16 {
+ type Output = Self;
+
+ #[inline]
+ fn neg(self) -> Self::Output {
+ Self(self.0 ^ 0x8000)
+ }
+}
+
+impl Neg for &f16 {
+ type Output = <f16 as Neg>::Output;
+
+ #[inline]
+ fn neg(self) -> Self::Output {
+ Neg::neg(*self)
+ }
+}
+
+impl Add for f16 {
+ type Output = Self;
+
+ #[inline]
+ fn add(self, rhs: Self) -> Self::Output {
+ Self::from_f32(Self::to_f32(self) + Self::to_f32(rhs))
+ }
+}
+
+impl Add<&f16> for f16 {
+ type Output = <f16 as Add<f16>>::Output;
+
+ #[inline]
+ fn add(self, rhs: &f16) -> Self::Output {
+ self.add(*rhs)
+ }
+}
+
+impl Add<&f16> for &f16 {
+ type Output = <f16 as Add<f16>>::Output;
+
+ #[inline]
+ fn add(self, rhs: &f16) -> Self::Output {
+ (*self).add(*rhs)
+ }
+}
+
+impl Add<f16> for &f16 {
+ type Output = <f16 as Add<f16>>::Output;
+
+ #[inline]
+ fn add(self, rhs: f16) -> Self::Output {
+ (*self).add(rhs)
+ }
+}
+
+impl AddAssign for f16 {
+ #[inline]
+ fn add_assign(&mut self, rhs: Self) {
+ *self = (*self).add(rhs);
+ }
+}
+
+impl AddAssign<&f16> for f16 {
+ #[inline]
+ fn add_assign(&mut self, rhs: &f16) {
+ *self = (*self).add(rhs);
+ }
+}
+
+impl Sub for f16 {
+ type Output = Self;
+
+ #[inline]
+ fn sub(self, rhs: Self) -> Self::Output {
+ Self::from_f32(Self::to_f32(self) - Self::to_f32(rhs))
+ }
+}
+
+impl Sub<&f16> for f16 {
+ type Output = <f16 as Sub<f16>>::Output;
+
+ #[inline]
+ fn sub(self, rhs: &f16) -> Self::Output {
+ self.sub(*rhs)
+ }
+}
+
+impl Sub<&f16> for &f16 {
+ type Output = <f16 as Sub<f16>>::Output;
+
+ #[inline]
+ fn sub(self, rhs: &f16) -> Self::Output {
+ (*self).sub(*rhs)
+ }
+}
+
+impl Sub<f16> for &f16 {
+ type Output = <f16 as Sub<f16>>::Output;
+
+ #[inline]
+ fn sub(self, rhs: f16) -> Self::Output {
+ (*self).sub(rhs)
+ }
+}
+
+impl SubAssign for f16 {
+ #[inline]
+ fn sub_assign(&mut self, rhs: Self) {
+ *self = (*self).sub(rhs);
+ }
+}
+
+impl SubAssign<&f16> for f16 {
+ #[inline]
+ fn sub_assign(&mut self, rhs: &f16) {
+ *self = (*self).sub(rhs);
+ }
+}
+
+impl Mul for f16 {
+ type Output = Self;
+
+ #[inline]
+ fn mul(self, rhs: Self) -> Self::Output {
+ Self::from_f32(Self::to_f32(self) * Self::to_f32(rhs))
+ }
+}
+
+impl Mul<&f16> for f16 {
+ type Output = <f16 as Mul<f16>>::Output;
+
+ #[inline]
+ fn mul(self, rhs: &f16) -> Self::Output {
+ self.mul(*rhs)
+ }
+}
+
+impl Mul<&f16> for &f16 {
+ type Output = <f16 as Mul<f16>>::Output;
+
+ #[inline]
+ fn mul(self, rhs: &f16) -> Self::Output {
+ (*self).mul(*rhs)
+ }
+}
+
+impl Mul<f16> for &f16 {
+ type Output = <f16 as Mul<f16>>::Output;
+
+ #[inline]
+ fn mul(self, rhs: f16) -> Self::Output {
+ (*self).mul(rhs)
+ }
+}
+
+impl MulAssign for f16 {
+ #[inline]
+ fn mul_assign(&mut self, rhs: Self) {
+ *self = (*self).mul(rhs);
+ }
+}
+
+impl MulAssign<&f16> for f16 {
+ #[inline]
+ fn mul_assign(&mut self, rhs: &f16) {
+ *self = (*self).mul(rhs);
+ }
+}
+
+impl Div for f16 {
+ type Output = Self;
+
+ #[inline]
+ fn div(self, rhs: Self) -> Self::Output {
+ Self::from_f32(Self::to_f32(self) / Self::to_f32(rhs))
+ }
+}
+
+impl Div<&f16> for f16 {
+ type Output = <f16 as Div<f16>>::Output;
+
+ #[inline]
+ fn div(self, rhs: &f16) -> Self::Output {
+ self.div(*rhs)
+ }
+}
+
+impl Div<&f16> for &f16 {
+ type Output = <f16 as Div<f16>>::Output;
+
+ #[inline]
+ fn div(self, rhs: &f16) -> Self::Output {
+ (*self).div(*rhs)
+ }
+}
+
+impl Div<f16> for &f16 {
+ type Output = <f16 as Div<f16>>::Output;
+
+ #[inline]
+ fn div(self, rhs: f16) -> Self::Output {
+ (*self).div(rhs)
+ }
+}
+
+impl DivAssign for f16 {
+ #[inline]
+ fn div_assign(&mut self, rhs: Self) {
+ *self = (*self).div(rhs);
+ }
+}
+
+impl DivAssign<&f16> for f16 {
+ #[inline]
+ fn div_assign(&mut self, rhs: &f16) {
+ *self = (*self).div(rhs);
+ }
+}
+
+impl Rem for f16 {
+ type Output = Self;
+
+ #[inline]
+ fn rem(self, rhs: Self) -> Self::Output {
+ Self::from_f32(Self::to_f32(self) % Self::to_f32(rhs))
+ }
+}
+
+impl Rem<&f16> for f16 {
+ type Output = <f16 as Rem<f16>>::Output;
+
+ #[inline]
+ fn rem(self, rhs: &f16) -> Self::Output {
+ self.rem(*rhs)
+ }
+}
+
+impl Rem<&f16> for &f16 {
+ type Output = <f16 as Rem<f16>>::Output;
+
+ #[inline]
+ fn rem(self, rhs: &f16) -> Self::Output {
+ (*self).rem(*rhs)
+ }
+}
+
+impl Rem<f16> for &f16 {
+ type Output = <f16 as Rem<f16>>::Output;
+
+ #[inline]
+ fn rem(self, rhs: f16) -> Self::Output {
+ (*self).rem(rhs)
+ }
+}
+
+impl RemAssign for f16 {
+ #[inline]
+ fn rem_assign(&mut self, rhs: Self) {
+ *self = (*self).rem(rhs);
+ }
+}
+
+impl RemAssign<&f16> for f16 {
+ #[inline]
+ fn rem_assign(&mut self, rhs: &f16) {
+ *self = (*self).rem(rhs);
+ }
+}
+
+impl Product for f16 {
+ #[inline]
+ fn product<I: Iterator<Item = Self>>(iter: I) -> Self {
+ f16::from_f32(iter.map(|f| f.to_f32()).product())
+ }
+}
+
+impl<'a> Product<&'a f16> for f16 {
+ #[inline]
+ fn product<I: Iterator<Item = &'a f16>>(iter: I) -> Self {
+ f16::from_f32(iter.map(|f| f.to_f32()).product())
+ }
+}
+
+impl Sum for f16 {
+ #[inline]
+ fn sum<I: Iterator<Item = Self>>(iter: I) -> Self {
+ f16::from_f32(iter.map(|f| f.to_f32()).sum())
+ }
+}
+
+impl<'a> Sum<&'a f16> for f16 {
+ #[inline]
+ fn sum<I: Iterator<Item = &'a f16>>(iter: I) -> Self {
+ f16::from_f32(iter.map(|f| f.to_f32()).product())
+ }
+}
+
+#[cfg(feature = "serde")]
+struct Visitor;
+
+#[cfg(feature = "serde")]
+impl<'de> Deserialize<'de> for f16 {
+ fn deserialize<D>(deserializer: D) -> Result<f16, D::Error>
+ where
+ D: serde::de::Deserializer<'de>,
+ {
+ deserializer.deserialize_newtype_struct("f16", Visitor)
+ }
+}
+
+#[cfg(feature = "serde")]
+impl<'de> serde::de::Visitor<'de> for Visitor {
+ type Value = f16;
+
+ fn expecting(&self, formatter: &mut alloc::fmt::Formatter) -> alloc::fmt::Result {
+ write!(formatter, "tuple struct f16")
+ }
+
+ fn visit_newtype_struct<D>(self, deserializer: D) -> Result<Self::Value, D::Error>
+ where
+ D: serde::Deserializer<'de>,
+ {
+ Ok(f16(<u16 as Deserialize>::deserialize(deserializer)?))
+ }
+
+ fn visit_str<E>(self, v: &str) -> Result<Self::Value, E>
+ where
+ E: serde::de::Error,
+ {
+ v.parse().map_err(|_| {
+ serde::de::Error::invalid_value(serde::de::Unexpected::Str(v), &"a float string")
+ })
+ }
+
+ fn visit_f32<E>(self, v: f32) -> Result<Self::Value, E>
+ where
+ E: serde::de::Error,
+ {
+ Ok(f16::from_f32(v))
+ }
+
+ fn visit_f64<E>(self, v: f64) -> Result<Self::Value, E>
+ where
+ E: serde::de::Error,
+ {
+ Ok(f16::from_f64(v))
+ }
+}
+
+#[allow(
+ clippy::cognitive_complexity,
+ clippy::float_cmp,
+ clippy::neg_cmp_op_on_partial_ord
+)]
+#[cfg(test)]
+mod test {
+ use super::*;
+ use core::cmp::Ordering;
+ #[cfg(feature = "num-traits")]
+ use num_traits::{AsPrimitive, FromPrimitive, ToPrimitive};
+ use quickcheck_macros::quickcheck;
+
+ #[cfg(feature = "num-traits")]
+ #[test]
+ fn as_primitive() {
+ let two = f16::from_f32(2.0);
+ assert_eq!(<i32 as AsPrimitive<f16>>::as_(2), two);
+ assert_eq!(<f16 as AsPrimitive<i32>>::as_(two), 2);
+
+ assert_eq!(<f32 as AsPrimitive<f16>>::as_(2.0), two);
+ assert_eq!(<f16 as AsPrimitive<f32>>::as_(two), 2.0);
+
+ assert_eq!(<f64 as AsPrimitive<f16>>::as_(2.0), two);
+ assert_eq!(<f16 as AsPrimitive<f64>>::as_(two), 2.0);
+ }
+
+ #[cfg(feature = "num-traits")]
+ #[test]
+ fn to_primitive() {
+ let two = f16::from_f32(2.0);
+ assert_eq!(ToPrimitive::to_i32(&two).unwrap(), 2i32);
+ assert_eq!(ToPrimitive::to_f32(&two).unwrap(), 2.0f32);
+ assert_eq!(ToPrimitive::to_f64(&two).unwrap(), 2.0f64);
+ }
+
+ #[cfg(feature = "num-traits")]
+ #[test]
+ fn from_primitive() {
+ let two = f16::from_f32(2.0);
+ assert_eq!(<f16 as FromPrimitive>::from_i32(2).unwrap(), two);
+ assert_eq!(<f16 as FromPrimitive>::from_f32(2.0).unwrap(), two);
+ assert_eq!(<f16 as FromPrimitive>::from_f64(2.0).unwrap(), two);
+ }
+
+ #[test]
+ fn test_f16_consts() {
+ // DIGITS
+ let digits = ((f16::MANTISSA_DIGITS as f32 - 1.0) * 2f32.log10()).floor() as u32;
+ assert_eq!(f16::DIGITS, digits);
+ // sanity check to show test is good
+ let digits32 = ((core::f32::MANTISSA_DIGITS as f32 - 1.0) * 2f32.log10()).floor() as u32;
+ assert_eq!(core::f32::DIGITS, digits32);
+
+ // EPSILON
+ let one = f16::from_f32(1.0);
+ let one_plus_epsilon = f16::from_bits(one.to_bits() + 1);
+ let epsilon = f16::from_f32(one_plus_epsilon.to_f32() - 1.0);
+ assert_eq!(f16::EPSILON, epsilon);
+ // sanity check to show test is good
+ let one_plus_epsilon32 = f32::from_bits(1.0f32.to_bits() + 1);
+ let epsilon32 = one_plus_epsilon32 - 1f32;
+ assert_eq!(core::f32::EPSILON, epsilon32);
+
+ // MAX, MIN and MIN_POSITIVE
+ let max = f16::from_bits(f16::INFINITY.to_bits() - 1);
+ let min = f16::from_bits(f16::NEG_INFINITY.to_bits() - 1);
+ let min_pos = f16::from_f32(2f32.powi(f16::MIN_EXP - 1));
+ assert_eq!(f16::MAX, max);
+ assert_eq!(f16::MIN, min);
+ assert_eq!(f16::MIN_POSITIVE, min_pos);
+ // sanity check to show test is good
+ let max32 = f32::from_bits(core::f32::INFINITY.to_bits() - 1);
+ let min32 = f32::from_bits(core::f32::NEG_INFINITY.to_bits() - 1);
+ let min_pos32 = 2f32.powi(core::f32::MIN_EXP - 1);
+ assert_eq!(core::f32::MAX, max32);
+ assert_eq!(core::f32::MIN, min32);
+ assert_eq!(core::f32::MIN_POSITIVE, min_pos32);
+
+ // MIN_10_EXP and MAX_10_EXP
+ let ten_to_min = 10f32.powi(f16::MIN_10_EXP);
+ assert!(ten_to_min / 10.0 < f16::MIN_POSITIVE.to_f32());
+ assert!(ten_to_min > f16::MIN_POSITIVE.to_f32());
+ let ten_to_max = 10f32.powi(f16::MAX_10_EXP);
+ assert!(ten_to_max < f16::MAX.to_f32());
+ assert!(ten_to_max * 10.0 > f16::MAX.to_f32());
+ // sanity check to show test is good
+ let ten_to_min32 = 10f64.powi(core::f32::MIN_10_EXP);
+ assert!(ten_to_min32 / 10.0 < f64::from(core::f32::MIN_POSITIVE));
+ assert!(ten_to_min32 > f64::from(core::f32::MIN_POSITIVE));
+ let ten_to_max32 = 10f64.powi(core::f32::MAX_10_EXP);
+ assert!(ten_to_max32 < f64::from(core::f32::MAX));
+ assert!(ten_to_max32 * 10.0 > f64::from(core::f32::MAX));
+ }
+
+ #[test]
+ fn test_f16_consts_from_f32() {
+ let one = f16::from_f32(1.0);
+ let zero = f16::from_f32(0.0);
+ let neg_zero = f16::from_f32(-0.0);
+ let neg_one = f16::from_f32(-1.0);
+ let inf = f16::from_f32(core::f32::INFINITY);
+ let neg_inf = f16::from_f32(core::f32::NEG_INFINITY);
+ let nan = f16::from_f32(core::f32::NAN);
+
+ assert_eq!(f16::ONE, one);
+ assert_eq!(f16::ZERO, zero);
+ assert!(zero.is_sign_positive());
+ assert_eq!(f16::NEG_ZERO, neg_zero);
+ assert!(neg_zero.is_sign_negative());
+ assert_eq!(f16::NEG_ONE, neg_one);
+ assert!(neg_one.is_sign_negative());
+ assert_eq!(f16::INFINITY, inf);
+ assert_eq!(f16::NEG_INFINITY, neg_inf);
+ assert!(nan.is_nan());
+ assert!(f16::NAN.is_nan());
+
+ let e = f16::from_f32(core::f32::consts::E);
+ let pi = f16::from_f32(core::f32::consts::PI);
+ let frac_1_pi = f16::from_f32(core::f32::consts::FRAC_1_PI);
+ let frac_1_sqrt_2 = f16::from_f32(core::f32::consts::FRAC_1_SQRT_2);
+ let frac_2_pi = f16::from_f32(core::f32::consts::FRAC_2_PI);
+ let frac_2_sqrt_pi = f16::from_f32(core::f32::consts::FRAC_2_SQRT_PI);
+ let frac_pi_2 = f16::from_f32(core::f32::consts::FRAC_PI_2);
+ let frac_pi_3 = f16::from_f32(core::f32::consts::FRAC_PI_3);
+ let frac_pi_4 = f16::from_f32(core::f32::consts::FRAC_PI_4);
+ let frac_pi_6 = f16::from_f32(core::f32::consts::FRAC_PI_6);
+ let frac_pi_8 = f16::from_f32(core::f32::consts::FRAC_PI_8);
+ let ln_10 = f16::from_f32(core::f32::consts::LN_10);
+ let ln_2 = f16::from_f32(core::f32::consts::LN_2);
+ let log10_e = f16::from_f32(core::f32::consts::LOG10_E);
+ // core::f32::consts::LOG10_2 requires rustc 1.43.0
+ let log10_2 = f16::from_f32(2f32.log10());
+ let log2_e = f16::from_f32(core::f32::consts::LOG2_E);
+ // core::f32::consts::LOG2_10 requires rustc 1.43.0
+ let log2_10 = f16::from_f32(10f32.log2());
+ let sqrt_2 = f16::from_f32(core::f32::consts::SQRT_2);
+
+ assert_eq!(f16::E, e);
+ assert_eq!(f16::PI, pi);
+ assert_eq!(f16::FRAC_1_PI, frac_1_pi);
+ assert_eq!(f16::FRAC_1_SQRT_2, frac_1_sqrt_2);
+ assert_eq!(f16::FRAC_2_PI, frac_2_pi);
+ assert_eq!(f16::FRAC_2_SQRT_PI, frac_2_sqrt_pi);
+ assert_eq!(f16::FRAC_PI_2, frac_pi_2);
+ assert_eq!(f16::FRAC_PI_3, frac_pi_3);
+ assert_eq!(f16::FRAC_PI_4, frac_pi_4);
+ assert_eq!(f16::FRAC_PI_6, frac_pi_6);
+ assert_eq!(f16::FRAC_PI_8, frac_pi_8);
+ assert_eq!(f16::LN_10, ln_10);
+ assert_eq!(f16::LN_2, ln_2);
+ assert_eq!(f16::LOG10_E, log10_e);
+ assert_eq!(f16::LOG10_2, log10_2);
+ assert_eq!(f16::LOG2_E, log2_e);
+ assert_eq!(f16::LOG2_10, log2_10);
+ assert_eq!(f16::SQRT_2, sqrt_2);
+ }
+
+ #[test]
+ fn test_f16_consts_from_f64() {
+ let one = f16::from_f64(1.0);
+ let zero = f16::from_f64(0.0);
+ let neg_zero = f16::from_f64(-0.0);
+ let inf = f16::from_f64(core::f64::INFINITY);
+ let neg_inf = f16::from_f64(core::f64::NEG_INFINITY);
+ let nan = f16::from_f64(core::f64::NAN);
+
+ assert_eq!(f16::ONE, one);
+ assert_eq!(f16::ZERO, zero);
+ assert!(zero.is_sign_positive());
+ assert_eq!(f16::NEG_ZERO, neg_zero);
+ assert!(neg_zero.is_sign_negative());
+ assert_eq!(f16::INFINITY, inf);
+ assert_eq!(f16::NEG_INFINITY, neg_inf);
+ assert!(nan.is_nan());
+ assert!(f16::NAN.is_nan());
+
+ let e = f16::from_f64(core::f64::consts::E);
+ let pi = f16::from_f64(core::f64::consts::PI);
+ let frac_1_pi = f16::from_f64(core::f64::consts::FRAC_1_PI);
+ let frac_1_sqrt_2 = f16::from_f64(core::f64::consts::FRAC_1_SQRT_2);
+ let frac_2_pi = f16::from_f64(core::f64::consts::FRAC_2_PI);
+ let frac_2_sqrt_pi = f16::from_f64(core::f64::consts::FRAC_2_SQRT_PI);
+ let frac_pi_2 = f16::from_f64(core::f64::consts::FRAC_PI_2);
+ let frac_pi_3 = f16::from_f64(core::f64::consts::FRAC_PI_3);
+ let frac_pi_4 = f16::from_f64(core::f64::consts::FRAC_PI_4);
+ let frac_pi_6 = f16::from_f64(core::f64::consts::FRAC_PI_6);
+ let frac_pi_8 = f16::from_f64(core::f64::consts::FRAC_PI_8);
+ let ln_10 = f16::from_f64(core::f64::consts::LN_10);
+ let ln_2 = f16::from_f64(core::f64::consts::LN_2);
+ let log10_e = f16::from_f64(core::f64::consts::LOG10_E);
+ // core::f64::consts::LOG10_2 requires rustc 1.43.0
+ let log10_2 = f16::from_f64(2f64.log10());
+ let log2_e = f16::from_f64(core::f64::consts::LOG2_E);
+ // core::f64::consts::LOG2_10 requires rustc 1.43.0
+ let log2_10 = f16::from_f64(10f64.log2());
+ let sqrt_2 = f16::from_f64(core::f64::consts::SQRT_2);
+
+ assert_eq!(f16::E, e);
+ assert_eq!(f16::PI, pi);
+ assert_eq!(f16::FRAC_1_PI, frac_1_pi);
+ assert_eq!(f16::FRAC_1_SQRT_2, frac_1_sqrt_2);
+ assert_eq!(f16::FRAC_2_PI, frac_2_pi);
+ assert_eq!(f16::FRAC_2_SQRT_PI, frac_2_sqrt_pi);
+ assert_eq!(f16::FRAC_PI_2, frac_pi_2);
+ assert_eq!(f16::FRAC_PI_3, frac_pi_3);
+ assert_eq!(f16::FRAC_PI_4, frac_pi_4);
+ assert_eq!(f16::FRAC_PI_6, frac_pi_6);
+ assert_eq!(f16::FRAC_PI_8, frac_pi_8);
+ assert_eq!(f16::LN_10, ln_10);
+ assert_eq!(f16::LN_2, ln_2);
+ assert_eq!(f16::LOG10_E, log10_e);
+ assert_eq!(f16::LOG10_2, log10_2);
+ assert_eq!(f16::LOG2_E, log2_e);
+ assert_eq!(f16::LOG2_10, log2_10);
+ assert_eq!(f16::SQRT_2, sqrt_2);
+ }
+
+ #[test]
+ fn test_nan_conversion_to_smaller() {
+ let nan64 = f64::from_bits(0x7FF0_0000_0000_0001u64);
+ let neg_nan64 = f64::from_bits(0xFFF0_0000_0000_0001u64);
+ let nan32 = f32::from_bits(0x7F80_0001u32);
+ let neg_nan32 = f32::from_bits(0xFF80_0001u32);
+ let nan32_from_64 = nan64 as f32;
+ let neg_nan32_from_64 = neg_nan64 as f32;
+ let nan16_from_64 = f16::from_f64(nan64);
+ let neg_nan16_from_64 = f16::from_f64(neg_nan64);
+ let nan16_from_32 = f16::from_f32(nan32);
+ let neg_nan16_from_32 = f16::from_f32(neg_nan32);
+
+ assert!(nan64.is_nan() && nan64.is_sign_positive());
+ assert!(neg_nan64.is_nan() && neg_nan64.is_sign_negative());
+ assert!(nan32.is_nan() && nan32.is_sign_positive());
+ assert!(neg_nan32.is_nan() && neg_nan32.is_sign_negative());
+ assert!(nan32_from_64.is_nan() && nan32_from_64.is_sign_positive());
+ assert!(neg_nan32_from_64.is_nan() && neg_nan32_from_64.is_sign_negative());
+ assert!(nan16_from_64.is_nan() && nan16_from_64.is_sign_positive());
+ assert!(neg_nan16_from_64.is_nan() && neg_nan16_from_64.is_sign_negative());
+ assert!(nan16_from_32.is_nan() && nan16_from_32.is_sign_positive());
+ assert!(neg_nan16_from_32.is_nan() && neg_nan16_from_32.is_sign_negative());
+ }
+
+ #[test]
+ fn test_nan_conversion_to_larger() {
+ let nan16 = f16::from_bits(0x7C01u16);
+ let neg_nan16 = f16::from_bits(0xFC01u16);
+ let nan32 = f32::from_bits(0x7F80_0001u32);
+ let neg_nan32 = f32::from_bits(0xFF80_0001u32);
+ let nan32_from_16 = f32::from(nan16);
+ let neg_nan32_from_16 = f32::from(neg_nan16);
+ let nan64_from_16 = f64::from(nan16);
+ let neg_nan64_from_16 = f64::from(neg_nan16);
+ let nan64_from_32 = f64::from(nan32);
+ let neg_nan64_from_32 = f64::from(neg_nan32);
+
+ assert!(nan16.is_nan() && nan16.is_sign_positive());
+ assert!(neg_nan16.is_nan() && neg_nan16.is_sign_negative());
+ assert!(nan32.is_nan() && nan32.is_sign_positive());
+ assert!(neg_nan32.is_nan() && neg_nan32.is_sign_negative());
+ assert!(nan32_from_16.is_nan() && nan32_from_16.is_sign_positive());
+ assert!(neg_nan32_from_16.is_nan() && neg_nan32_from_16.is_sign_negative());
+ assert!(nan64_from_16.is_nan() && nan64_from_16.is_sign_positive());
+ assert!(neg_nan64_from_16.is_nan() && neg_nan64_from_16.is_sign_negative());
+ assert!(nan64_from_32.is_nan() && nan64_from_32.is_sign_positive());
+ assert!(neg_nan64_from_32.is_nan() && neg_nan64_from_32.is_sign_negative());
+ }
+
+ #[test]
+ fn test_f16_to_f32() {
+ let f = f16::from_f32(7.0);
+ assert_eq!(f.to_f32(), 7.0f32);
+
+ // 7.1 is NOT exactly representable in 16-bit, it's rounded
+ let f = f16::from_f32(7.1);
+ let diff = (f.to_f32() - 7.1f32).abs();
+ // diff must be <= 4 * EPSILON, as 7 has two more significant bits than 1
+ assert!(diff <= 4.0 * f16::EPSILON.to_f32());
+
+ assert_eq!(f16::from_bits(0x0000_0001).to_f32(), 2.0f32.powi(-24));
+ assert_eq!(f16::from_bits(0x0000_0005).to_f32(), 5.0 * 2.0f32.powi(-24));
+
+ assert_eq!(f16::from_bits(0x0000_0001), f16::from_f32(2.0f32.powi(-24)));
+ assert_eq!(
+ f16::from_bits(0x0000_0005),
+ f16::from_f32(5.0 * 2.0f32.powi(-24))
+ );
+ }
+
+ #[test]
+ fn test_f16_to_f64() {
+ let f = f16::from_f64(7.0);
+ assert_eq!(f.to_f64(), 7.0f64);
+
+ // 7.1 is NOT exactly representable in 16-bit, it's rounded
+ let f = f16::from_f64(7.1);
+ let diff = (f.to_f64() - 7.1f64).abs();
+ // diff must be <= 4 * EPSILON, as 7 has two more significant bits than 1
+ assert!(diff <= 4.0 * f16::EPSILON.to_f64());
+
+ assert_eq!(f16::from_bits(0x0000_0001).to_f64(), 2.0f64.powi(-24));
+ assert_eq!(f16::from_bits(0x0000_0005).to_f64(), 5.0 * 2.0f64.powi(-24));
+
+ assert_eq!(f16::from_bits(0x0000_0001), f16::from_f64(2.0f64.powi(-24)));
+ assert_eq!(
+ f16::from_bits(0x0000_0005),
+ f16::from_f64(5.0 * 2.0f64.powi(-24))
+ );
+ }
+
+ #[test]
+ fn test_comparisons() {
+ let zero = f16::from_f64(0.0);
+ let one = f16::from_f64(1.0);
+ let neg_zero = f16::from_f64(-0.0);
+ let neg_one = f16::from_f64(-1.0);
+
+ assert_eq!(zero.partial_cmp(&neg_zero), Some(Ordering::Equal));
+ assert_eq!(neg_zero.partial_cmp(&zero), Some(Ordering::Equal));
+ assert!(zero == neg_zero);
+ assert!(neg_zero == zero);
+ assert!(!(zero != neg_zero));
+ assert!(!(neg_zero != zero));
+ assert!(!(zero < neg_zero));
+ assert!(!(neg_zero < zero));
+ assert!(zero <= neg_zero);
+ assert!(neg_zero <= zero);
+ assert!(!(zero > neg_zero));
+ assert!(!(neg_zero > zero));
+ assert!(zero >= neg_zero);
+ assert!(neg_zero >= zero);
+
+ assert_eq!(one.partial_cmp(&neg_zero), Some(Ordering::Greater));
+ assert_eq!(neg_zero.partial_cmp(&one), Some(Ordering::Less));
+ assert!(!(one == neg_zero));
+ assert!(!(neg_zero == one));
+ assert!(one != neg_zero);
+ assert!(neg_zero != one);
+ assert!(!(one < neg_zero));
+ assert!(neg_zero < one);
+ assert!(!(one <= neg_zero));
+ assert!(neg_zero <= one);
+ assert!(one > neg_zero);
+ assert!(!(neg_zero > one));
+ assert!(one >= neg_zero);
+ assert!(!(neg_zero >= one));
+
+ assert_eq!(one.partial_cmp(&neg_one), Some(Ordering::Greater));
+ assert_eq!(neg_one.partial_cmp(&one), Some(Ordering::Less));
+ assert!(!(one == neg_one));
+ assert!(!(neg_one == one));
+ assert!(one != neg_one);
+ assert!(neg_one != one);
+ assert!(!(one < neg_one));
+ assert!(neg_one < one);
+ assert!(!(one <= neg_one));
+ assert!(neg_one <= one);
+ assert!(one > neg_one);
+ assert!(!(neg_one > one));
+ assert!(one >= neg_one);
+ assert!(!(neg_one >= one));
+ }
+
+ #[test]
+ #[allow(clippy::erasing_op, clippy::identity_op)]
+ fn round_to_even_f32() {
+ // smallest positive subnormal = 0b0.0000_0000_01 * 2^-14 = 2^-24
+ let min_sub = f16::from_bits(1);
+ let min_sub_f = (-24f32).exp2();
+ assert_eq!(f16::from_f32(min_sub_f).to_bits(), min_sub.to_bits());
+ assert_eq!(f32::from(min_sub).to_bits(), min_sub_f.to_bits());
+
+ // 0.0000000000_011111 rounded to 0.0000000000 (< tie, no rounding)
+ // 0.0000000000_100000 rounded to 0.0000000000 (tie and even, remains at even)
+ // 0.0000000000_100001 rounded to 0.0000000001 (> tie, rounds up)
+ assert_eq!(
+ f16::from_f32(min_sub_f * 0.49).to_bits(),
+ min_sub.to_bits() * 0
+ );
+ assert_eq!(
+ f16::from_f32(min_sub_f * 0.50).to_bits(),
+ min_sub.to_bits() * 0
+ );
+ assert_eq!(
+ f16::from_f32(min_sub_f * 0.51).to_bits(),
+ min_sub.to_bits() * 1
+ );
+
+ // 0.0000000001_011111 rounded to 0.0000000001 (< tie, no rounding)
+ // 0.0000000001_100000 rounded to 0.0000000010 (tie and odd, rounds up to even)
+ // 0.0000000001_100001 rounded to 0.0000000010 (> tie, rounds up)
+ assert_eq!(
+ f16::from_f32(min_sub_f * 1.49).to_bits(),
+ min_sub.to_bits() * 1
+ );
+ assert_eq!(
+ f16::from_f32(min_sub_f * 1.50).to_bits(),
+ min_sub.to_bits() * 2
+ );
+ assert_eq!(
+ f16::from_f32(min_sub_f * 1.51).to_bits(),
+ min_sub.to_bits() * 2
+ );
+
+ // 0.0000000010_011111 rounded to 0.0000000010 (< tie, no rounding)
+ // 0.0000000010_100000 rounded to 0.0000000010 (tie and even, remains at even)
+ // 0.0000000010_100001 rounded to 0.0000000011 (> tie, rounds up)
+ assert_eq!(
+ f16::from_f32(min_sub_f * 2.49).to_bits(),
+ min_sub.to_bits() * 2
+ );
+ assert_eq!(
+ f16::from_f32(min_sub_f * 2.50).to_bits(),
+ min_sub.to_bits() * 2
+ );
+ assert_eq!(
+ f16::from_f32(min_sub_f * 2.51).to_bits(),
+ min_sub.to_bits() * 3
+ );
+
+ assert_eq!(
+ f16::from_f32(2000.49f32).to_bits(),
+ f16::from_f32(2000.0).to_bits()
+ );
+ assert_eq!(
+ f16::from_f32(2000.50f32).to_bits(),
+ f16::from_f32(2000.0).to_bits()
+ );
+ assert_eq!(
+ f16::from_f32(2000.51f32).to_bits(),
+ f16::from_f32(2001.0).to_bits()
+ );
+ assert_eq!(
+ f16::from_f32(2001.49f32).to_bits(),
+ f16::from_f32(2001.0).to_bits()
+ );
+ assert_eq!(
+ f16::from_f32(2001.50f32).to_bits(),
+ f16::from_f32(2002.0).to_bits()
+ );
+ assert_eq!(
+ f16::from_f32(2001.51f32).to_bits(),
+ f16::from_f32(2002.0).to_bits()
+ );
+ assert_eq!(
+ f16::from_f32(2002.49f32).to_bits(),
+ f16::from_f32(2002.0).to_bits()
+ );
+ assert_eq!(
+ f16::from_f32(2002.50f32).to_bits(),
+ f16::from_f32(2002.0).to_bits()
+ );
+ assert_eq!(
+ f16::from_f32(2002.51f32).to_bits(),
+ f16::from_f32(2003.0).to_bits()
+ );
+ }
+
+ #[test]
+ #[allow(clippy::erasing_op, clippy::identity_op)]
+ fn round_to_even_f64() {
+ // smallest positive subnormal = 0b0.0000_0000_01 * 2^-14 = 2^-24
+ let min_sub = f16::from_bits(1);
+ let min_sub_f = (-24f64).exp2();
+ assert_eq!(f16::from_f64(min_sub_f).to_bits(), min_sub.to_bits());
+ assert_eq!(f64::from(min_sub).to_bits(), min_sub_f.to_bits());
+
+ // 0.0000000000_011111 rounded to 0.0000000000 (< tie, no rounding)
+ // 0.0000000000_100000 rounded to 0.0000000000 (tie and even, remains at even)
+ // 0.0000000000_100001 rounded to 0.0000000001 (> tie, rounds up)
+ assert_eq!(
+ f16::from_f64(min_sub_f * 0.49).to_bits(),
+ min_sub.to_bits() * 0
+ );
+ assert_eq!(
+ f16::from_f64(min_sub_f * 0.50).to_bits(),
+ min_sub.to_bits() * 0
+ );
+ assert_eq!(
+ f16::from_f64(min_sub_f * 0.51).to_bits(),
+ min_sub.to_bits() * 1
+ );
+
+ // 0.0000000001_011111 rounded to 0.0000000001 (< tie, no rounding)
+ // 0.0000000001_100000 rounded to 0.0000000010 (tie and odd, rounds up to even)
+ // 0.0000000001_100001 rounded to 0.0000000010 (> tie, rounds up)
+ assert_eq!(
+ f16::from_f64(min_sub_f * 1.49).to_bits(),
+ min_sub.to_bits() * 1
+ );
+ assert_eq!(
+ f16::from_f64(min_sub_f * 1.50).to_bits(),
+ min_sub.to_bits() * 2
+ );
+ assert_eq!(
+ f16::from_f64(min_sub_f * 1.51).to_bits(),
+ min_sub.to_bits() * 2
+ );
+
+ // 0.0000000010_011111 rounded to 0.0000000010 (< tie, no rounding)
+ // 0.0000000010_100000 rounded to 0.0000000010 (tie and even, remains at even)
+ // 0.0000000010_100001 rounded to 0.0000000011 (> tie, rounds up)
+ assert_eq!(
+ f16::from_f64(min_sub_f * 2.49).to_bits(),
+ min_sub.to_bits() * 2
+ );
+ assert_eq!(
+ f16::from_f64(min_sub_f * 2.50).to_bits(),
+ min_sub.to_bits() * 2
+ );
+ assert_eq!(
+ f16::from_f64(min_sub_f * 2.51).to_bits(),
+ min_sub.to_bits() * 3
+ );
+
+ assert_eq!(
+ f16::from_f64(2000.49f64).to_bits(),
+ f16::from_f64(2000.0).to_bits()
+ );
+ assert_eq!(
+ f16::from_f64(2000.50f64).to_bits(),
+ f16::from_f64(2000.0).to_bits()
+ );
+ assert_eq!(
+ f16::from_f64(2000.51f64).to_bits(),
+ f16::from_f64(2001.0).to_bits()
+ );
+ assert_eq!(
+ f16::from_f64(2001.49f64).to_bits(),
+ f16::from_f64(2001.0).to_bits()
+ );
+ assert_eq!(
+ f16::from_f64(2001.50f64).to_bits(),
+ f16::from_f64(2002.0).to_bits()
+ );
+ assert_eq!(
+ f16::from_f64(2001.51f64).to_bits(),
+ f16::from_f64(2002.0).to_bits()
+ );
+ assert_eq!(
+ f16::from_f64(2002.49f64).to_bits(),
+ f16::from_f64(2002.0).to_bits()
+ );
+ assert_eq!(
+ f16::from_f64(2002.50f64).to_bits(),
+ f16::from_f64(2002.0).to_bits()
+ );
+ assert_eq!(
+ f16::from_f64(2002.51f64).to_bits(),
+ f16::from_f64(2003.0).to_bits()
+ );
+ }
+
+ impl quickcheck::Arbitrary for f16 {
+ fn arbitrary(g: &mut quickcheck::Gen) -> Self {
+ f16(u16::arbitrary(g))
+ }
+ }
+
+ #[quickcheck]
+ fn qc_roundtrip_f16_f32_is_identity(f: f16) -> bool {
+ let roundtrip = f16::from_f32(f.to_f32());
+ if f.is_nan() {
+ roundtrip.is_nan() && f.is_sign_negative() == roundtrip.is_sign_negative()
+ } else {
+ f.0 == roundtrip.0
+ }
+ }
+
+ #[quickcheck]
+ fn qc_roundtrip_f16_f64_is_identity(f: f16) -> bool {
+ let roundtrip = f16::from_f64(f.to_f64());
+ if f.is_nan() {
+ roundtrip.is_nan() && f.is_sign_negative() == roundtrip.is_sign_negative()
+ } else {
+ f.0 == roundtrip.0
+ }
+ }
+}
--- /dev/null
+#![allow(dead_code, unused_imports)]
+use crate::leading_zeros::leading_zeros_u16;
+use core::mem;
+
+macro_rules! convert_fn {
+ (fn $name:ident($($var:ident : $vartype:ty),+) -> $restype:ty {
+ if feature("f16c") { $f16c:expr }
+ else { $fallback:expr }}) => {
+ #[inline]
+ pub(crate) fn $name($($var: $vartype),+) -> $restype {
+ // Use CPU feature detection if using std
+ #[cfg(all(
+ feature = "use-intrinsics",
+ feature = "std",
+ any(target_arch = "x86", target_arch = "x86_64"),
+ not(target_feature = "f16c")
+ ))]
+ {
+ if is_x86_feature_detected!("f16c") {
+ $f16c
+ } else {
+ $fallback
+ }
+ }
+ // Use intrinsics directly when a compile target or using no_std
+ #[cfg(all(
+ feature = "use-intrinsics",
+ any(target_arch = "x86", target_arch = "x86_64"),
+ target_feature = "f16c"
+ ))]
+ {
+ $f16c
+ }
+ // Fallback to software
+ #[cfg(any(
+ not(feature = "use-intrinsics"),
+ not(any(target_arch = "x86", target_arch = "x86_64")),
+ all(not(feature = "std"), not(target_feature = "f16c"))
+ ))]
+ {
+ $fallback
+ }
+ }
+ };
+}
+
+convert_fn! {
+ fn f32_to_f16(f: f32) -> u16 {
+ if feature("f16c") {
+ unsafe { x86::f32_to_f16_x86_f16c(f) }
+ } else {
+ f32_to_f16_fallback(f)
+ }
+ }
+}
+
+convert_fn! {
+ fn f64_to_f16(f: f64) -> u16 {
+ if feature("f16c") {
+ unsafe { x86::f32_to_f16_x86_f16c(f as f32) }
+ } else {
+ f64_to_f16_fallback(f)
+ }
+ }
+}
+
+convert_fn! {
+ fn f16_to_f32(i: u16) -> f32 {
+ if feature("f16c") {
+ unsafe { x86::f16_to_f32_x86_f16c(i) }
+ } else {
+ f16_to_f32_fallback(i)
+ }
+ }
+}
+
+convert_fn! {
+ fn f16_to_f64(i: u16) -> f64 {
+ if feature("f16c") {
+ unsafe { x86::f16_to_f32_x86_f16c(i) as f64 }
+ } else {
+ f16_to_f64_fallback(i)
+ }
+ }
+}
+
+convert_fn! {
+ fn f32x4_to_f16x4(f: &[f32; 4]) -> [u16; 4] {
+ if feature("f16c") {
+ unsafe { x86::f32x4_to_f16x4_x86_f16c(f) }
+ } else {
+ f32x4_to_f16x4_fallback(f)
+ }
+ }
+}
+
+convert_fn! {
+ fn f16x4_to_f32x4(i: &[u16; 4]) -> [f32; 4] {
+ if feature("f16c") {
+ unsafe { x86::f16x4_to_f32x4_x86_f16c(i) }
+ } else {
+ f16x4_to_f32x4_fallback(i)
+ }
+ }
+}
+
+convert_fn! {
+ fn f64x4_to_f16x4(f: &[f64; 4]) -> [u16; 4] {
+ if feature("f16c") {
+ unsafe { x86::f64x4_to_f16x4_x86_f16c(f) }
+ } else {
+ f64x4_to_f16x4_fallback(f)
+ }
+ }
+}
+
+convert_fn! {
+ fn f16x4_to_f64x4(i: &[u16; 4]) -> [f64; 4] {
+ if feature("f16c") {
+ unsafe { x86::f16x4_to_f64x4_x86_f16c(i) }
+ } else {
+ f16x4_to_f64x4_fallback(i)
+ }
+ }
+}
+
+convert_fn! {
+ fn f32x8_to_f16x8(f: &[f32; 8]) -> [u16; 8] {
+ if feature("f16c") {
+ unsafe { x86::f32x8_to_f16x8_x86_f16c(f) }
+ } else {
+ f32x8_to_f16x8_fallback(f)
+ }
+ }
+}
+
+convert_fn! {
+ fn f16x8_to_f32x8(i: &[u16; 8]) -> [f32; 8] {
+ if feature("f16c") {
+ unsafe { x86::f16x8_to_f32x8_x86_f16c(i) }
+ } else {
+ f16x8_to_f32x8_fallback(i)
+ }
+ }
+}
+
+convert_fn! {
+ fn f64x8_to_f16x8(f: &[f64; 8]) -> [u16; 8] {
+ if feature("f16c") {
+ unsafe { x86::f64x8_to_f16x8_x86_f16c(f) }
+ } else {
+ f64x8_to_f16x8_fallback(f)
+ }
+ }
+}
+
+convert_fn! {
+ fn f16x8_to_f64x8(i: &[u16; 8]) -> [f64; 8] {
+ if feature("f16c") {
+ unsafe { x86::f16x8_to_f64x8_x86_f16c(i) }
+ } else {
+ f16x8_to_f64x8_fallback(i)
+ }
+ }
+}
+
+convert_fn! {
+ fn f32_to_f16_slice(src: &[f32], dst: &mut [u16]) -> () {
+ if feature("f16c") {
+ convert_chunked_slice_8(src, dst, x86::f32x8_to_f16x8_x86_f16c,
+ x86::f32x4_to_f16x4_x86_f16c)
+ } else {
+ slice_fallback(src, dst, f32_to_f16_fallback)
+ }
+ }
+}
+
+convert_fn! {
+ fn f16_to_f32_slice(src: &[u16], dst: &mut [f32]) -> () {
+ if feature("f16c") {
+ convert_chunked_slice_8(src, dst, x86::f16x8_to_f32x8_x86_f16c,
+ x86::f16x4_to_f32x4_x86_f16c)
+ } else {
+ slice_fallback(src, dst, f16_to_f32_fallback)
+ }
+ }
+}
+
+convert_fn! {
+ fn f64_to_f16_slice(src: &[f64], dst: &mut [u16]) -> () {
+ if feature("f16c") {
+ convert_chunked_slice_8(src, dst, x86::f64x8_to_f16x8_x86_f16c,
+ x86::f64x4_to_f16x4_x86_f16c)
+ } else {
+ slice_fallback(src, dst, f64_to_f16_fallback)
+ }
+ }
+}
+
+convert_fn! {
+ fn f16_to_f64_slice(src: &[u16], dst: &mut [f64]) -> () {
+ if feature("f16c") {
+ convert_chunked_slice_8(src, dst, x86::f16x8_to_f64x8_x86_f16c,
+ x86::f16x4_to_f64x4_x86_f16c)
+ } else {
+ slice_fallback(src, dst, f16_to_f64_fallback)
+ }
+ }
+}
+
+/// Chunks sliced into x8 or x4 arrays
+#[inline]
+fn convert_chunked_slice_8<S: Copy + Default, D: Copy>(
+ src: &[S],
+ dst: &mut [D],
+ fn8: unsafe fn(&[S; 8]) -> [D; 8],
+ fn4: unsafe fn(&[S; 4]) -> [D; 4],
+) {
+ assert_eq!(src.len(), dst.len());
+
+ // TODO: Can be further optimized with array_chunks when it becomes stabilized
+
+ let src_chunks = src.chunks_exact(8);
+ let mut dst_chunks = dst.chunks_exact_mut(8);
+ let src_remainder = src_chunks.remainder();
+ for (s, d) in src_chunks.zip(&mut dst_chunks) {
+ let chunk: &[S; 8] = s.try_into().unwrap();
+ d.copy_from_slice(unsafe { &fn8(chunk) });
+ }
+
+ // Process remainder
+ if src_remainder.len() > 4 {
+ let mut buf: [S; 8] = Default::default();
+ buf[..src_remainder.len()].copy_from_slice(src_remainder);
+ let vec = unsafe { fn8(&buf) };
+ let dst_remainder = dst_chunks.into_remainder();
+ dst_remainder.copy_from_slice(&vec[..dst_remainder.len()]);
+ } else if !src_remainder.is_empty() {
+ let mut buf: [S; 4] = Default::default();
+ buf[..src_remainder.len()].copy_from_slice(src_remainder);
+ let vec = unsafe { fn4(&buf) };
+ let dst_remainder = dst_chunks.into_remainder();
+ dst_remainder.copy_from_slice(&vec[..dst_remainder.len()]);
+ }
+}
+
+/// Chunks sliced into x4 arrays
+#[inline]
+fn convert_chunked_slice_4<S: Copy + Default, D: Copy>(
+ src: &[S],
+ dst: &mut [D],
+ f: unsafe fn(&[S; 4]) -> [D; 4],
+) {
+ assert_eq!(src.len(), dst.len());
+
+ // TODO: Can be further optimized with array_chunks when it becomes stabilized
+
+ let src_chunks = src.chunks_exact(4);
+ let mut dst_chunks = dst.chunks_exact_mut(4);
+ let src_remainder = src_chunks.remainder();
+ for (s, d) in src_chunks.zip(&mut dst_chunks) {
+ let chunk: &[S; 4] = s.try_into().unwrap();
+ d.copy_from_slice(unsafe { &f(chunk) });
+ }
+
+ // Process remainder
+ if !src_remainder.is_empty() {
+ let mut buf: [S; 4] = Default::default();
+ buf[..src_remainder.len()].copy_from_slice(src_remainder);
+ let vec = unsafe { f(&buf) };
+ let dst_remainder = dst_chunks.into_remainder();
+ dst_remainder.copy_from_slice(&vec[..dst_remainder.len()]);
+ }
+}
+
+/////////////// Fallbacks ////////////////
+
+// In the below functions, round to nearest, with ties to even.
+// Let us call the most significant bit that will be shifted out the round_bit.
+//
+// Round up if either
+// a) Removed part > tie.
+// (mantissa & round_bit) != 0 && (mantissa & (round_bit - 1)) != 0
+// b) Removed part == tie, and retained part is odd.
+// (mantissa & round_bit) != 0 && (mantissa & (2 * round_bit)) != 0
+// (If removed part == tie and retained part is even, do not round up.)
+// These two conditions can be combined into one:
+// (mantissa & round_bit) != 0 && (mantissa & ((round_bit - 1) | (2 * round_bit))) != 0
+// which can be simplified into
+// (mantissa & round_bit) != 0 && (mantissa & (3 * round_bit - 1)) != 0
+
+#[inline]
+pub(crate) const fn f32_to_f16_fallback(value: f32) -> u16 {
+ // TODO: Replace mem::transmute with to_bits() once to_bits is const-stabilized
+ // Convert to raw bytes
+ let x: u32 = unsafe { mem::transmute(value) };
+
+ // Extract IEEE754 components
+ let sign = x & 0x8000_0000u32;
+ let exp = x & 0x7F80_0000u32;
+ let man = x & 0x007F_FFFFu32;
+
+ // Check for all exponent bits being set, which is Infinity or NaN
+ if exp == 0x7F80_0000u32 {
+ // Set mantissa MSB for NaN (and also keep shifted mantissa bits)
+ let nan_bit = if man == 0 { 0 } else { 0x0200u32 };
+ return ((sign >> 16) | 0x7C00u32 | nan_bit | (man >> 13)) as u16;
+ }
+
+ // The number is normalized, start assembling half precision version
+ let half_sign = sign >> 16;
+ // Unbias the exponent, then bias for half precision
+ let unbiased_exp = ((exp >> 23) as i32) - 127;
+ let half_exp = unbiased_exp + 15;
+
+ // Check for exponent overflow, return +infinity
+ if half_exp >= 0x1F {
+ return (half_sign | 0x7C00u32) as u16;
+ }
+
+ // Check for underflow
+ if half_exp <= 0 {
+ // Check mantissa for what we can do
+ if 14 - half_exp > 24 {
+ // No rounding possibility, so this is a full underflow, return signed zero
+ return half_sign as u16;
+ }
+ // Don't forget about hidden leading mantissa bit when assembling mantissa
+ let man = man | 0x0080_0000u32;
+ let mut half_man = man >> (14 - half_exp);
+ // Check for rounding (see comment above functions)
+ let round_bit = 1 << (13 - half_exp);
+ if (man & round_bit) != 0 && (man & (3 * round_bit - 1)) != 0 {
+ half_man += 1;
+ }
+ // No exponent for subnormals
+ return (half_sign | half_man) as u16;
+ }
+
+ // Rebias the exponent
+ let half_exp = (half_exp as u32) << 10;
+ let half_man = man >> 13;
+ // Check for rounding (see comment above functions)
+ let round_bit = 0x0000_1000u32;
+ if (man & round_bit) != 0 && (man & (3 * round_bit - 1)) != 0 {
+ // Round it
+ ((half_sign | half_exp | half_man) + 1) as u16
+ } else {
+ (half_sign | half_exp | half_man) as u16
+ }
+}
+
+#[inline]
+pub(crate) const fn f64_to_f16_fallback(value: f64) -> u16 {
+ // Convert to raw bytes, truncating the last 32-bits of mantissa; that precision will always
+ // be lost on half-precision.
+ // TODO: Replace mem::transmute with to_bits() once to_bits is const-stabilized
+ let val: u64 = unsafe { mem::transmute(value) };
+ let x = (val >> 32) as u32;
+
+ // Extract IEEE754 components
+ let sign = x & 0x8000_0000u32;
+ let exp = x & 0x7FF0_0000u32;
+ let man = x & 0x000F_FFFFu32;
+
+ // Check for all exponent bits being set, which is Infinity or NaN
+ if exp == 0x7FF0_0000u32 {
+ // Set mantissa MSB for NaN (and also keep shifted mantissa bits).
+ // We also have to check the last 32 bits.
+ let nan_bit = if man == 0 && (val as u32 == 0) {
+ 0
+ } else {
+ 0x0200u32
+ };
+ return ((sign >> 16) | 0x7C00u32 | nan_bit | (man >> 10)) as u16;
+ }
+
+ // The number is normalized, start assembling half precision version
+ let half_sign = sign >> 16;
+ // Unbias the exponent, then bias for half precision
+ let unbiased_exp = ((exp >> 20) as i64) - 1023;
+ let half_exp = unbiased_exp + 15;
+
+ // Check for exponent overflow, return +infinity
+ if half_exp >= 0x1F {
+ return (half_sign | 0x7C00u32) as u16;
+ }
+
+ // Check for underflow
+ if half_exp <= 0 {
+ // Check mantissa for what we can do
+ if 10 - half_exp > 21 {
+ // No rounding possibility, so this is a full underflow, return signed zero
+ return half_sign as u16;
+ }
+ // Don't forget about hidden leading mantissa bit when assembling mantissa
+ let man = man | 0x0010_0000u32;
+ let mut half_man = man >> (11 - half_exp);
+ // Check for rounding (see comment above functions)
+ let round_bit = 1 << (10 - half_exp);
+ if (man & round_bit) != 0 && (man & (3 * round_bit - 1)) != 0 {
+ half_man += 1;
+ }
+ // No exponent for subnormals
+ return (half_sign | half_man) as u16;
+ }
+
+ // Rebias the exponent
+ let half_exp = (half_exp as u32) << 10;
+ let half_man = man >> 10;
+ // Check for rounding (see comment above functions)
+ let round_bit = 0x0000_0200u32;
+ if (man & round_bit) != 0 && (man & (3 * round_bit - 1)) != 0 {
+ // Round it
+ ((half_sign | half_exp | half_man) + 1) as u16
+ } else {
+ (half_sign | half_exp | half_man) as u16
+ }
+}
+
+#[inline]
+pub(crate) const fn f16_to_f32_fallback(i: u16) -> f32 {
+ // Check for signed zero
+ // TODO: Replace mem::transmute with from_bits() once from_bits is const-stabilized
+ if i & 0x7FFFu16 == 0 {
+ return unsafe { mem::transmute((i as u32) << 16) };
+ }
+
+ let half_sign = (i & 0x8000u16) as u32;
+ let half_exp = (i & 0x7C00u16) as u32;
+ let half_man = (i & 0x03FFu16) as u32;
+
+ // Check for an infinity or NaN when all exponent bits set
+ if half_exp == 0x7C00u32 {
+ // Check for signed infinity if mantissa is zero
+ if half_man == 0 {
+ return unsafe { mem::transmute((half_sign << 16) | 0x7F80_0000u32) };
+ } else {
+ // NaN, keep current mantissa but also set most significiant mantissa bit
+ return unsafe {
+ mem::transmute((half_sign << 16) | 0x7FC0_0000u32 | (half_man << 13))
+ };
+ }
+ }
+
+ // Calculate single-precision components with adjusted exponent
+ let sign = half_sign << 16;
+ // Unbias exponent
+ let unbiased_exp = ((half_exp as i32) >> 10) - 15;
+
+ // Check for subnormals, which will be normalized by adjusting exponent
+ if half_exp == 0 {
+ // Calculate how much to adjust the exponent by
+ let e = leading_zeros_u16(half_man as u16) - 6;
+
+ // Rebias and adjust exponent
+ let exp = (127 - 15 - e) << 23;
+ let man = (half_man << (14 + e)) & 0x7F_FF_FFu32;
+ return unsafe { mem::transmute(sign | exp | man) };
+ }
+
+ // Rebias exponent for a normalized normal
+ let exp = ((unbiased_exp + 127) as u32) << 23;
+ let man = (half_man & 0x03FFu32) << 13;
+ unsafe { mem::transmute(sign | exp | man) }
+}
+
+#[inline]
+pub(crate) const fn f16_to_f64_fallback(i: u16) -> f64 {
+ // Check for signed zero
+ // TODO: Replace mem::transmute with from_bits() once from_bits is const-stabilized
+ if i & 0x7FFFu16 == 0 {
+ return unsafe { mem::transmute((i as u64) << 48) };
+ }
+
+ let half_sign = (i & 0x8000u16) as u64;
+ let half_exp = (i & 0x7C00u16) as u64;
+ let half_man = (i & 0x03FFu16) as u64;
+
+ // Check for an infinity or NaN when all exponent bits set
+ if half_exp == 0x7C00u64 {
+ // Check for signed infinity if mantissa is zero
+ if half_man == 0 {
+ return unsafe { mem::transmute((half_sign << 48) | 0x7FF0_0000_0000_0000u64) };
+ } else {
+ // NaN, keep current mantissa but also set most significiant mantissa bit
+ return unsafe {
+ mem::transmute((half_sign << 48) | 0x7FF8_0000_0000_0000u64 | (half_man << 42))
+ };
+ }
+ }
+
+ // Calculate double-precision components with adjusted exponent
+ let sign = half_sign << 48;
+ // Unbias exponent
+ let unbiased_exp = ((half_exp as i64) >> 10) - 15;
+
+ // Check for subnormals, which will be normalized by adjusting exponent
+ if half_exp == 0 {
+ // Calculate how much to adjust the exponent by
+ let e = leading_zeros_u16(half_man as u16) - 6;
+
+ // Rebias and adjust exponent
+ let exp = ((1023 - 15 - e) as u64) << 52;
+ let man = (half_man << (43 + e)) & 0xF_FFFF_FFFF_FFFFu64;
+ return unsafe { mem::transmute(sign | exp | man) };
+ }
+
+ // Rebias exponent for a normalized normal
+ let exp = ((unbiased_exp + 1023) as u64) << 52;
+ let man = (half_man & 0x03FFu64) << 42;
+ unsafe { mem::transmute(sign | exp | man) }
+}
+
+#[inline]
+fn f16x4_to_f32x4_fallback(v: &[u16; 4]) -> [f32; 4] {
+ [
+ f16_to_f32_fallback(v[0]),
+ f16_to_f32_fallback(v[1]),
+ f16_to_f32_fallback(v[2]),
+ f16_to_f32_fallback(v[3]),
+ ]
+}
+
+#[inline]
+fn f32x4_to_f16x4_fallback(v: &[f32; 4]) -> [u16; 4] {
+ [
+ f32_to_f16_fallback(v[0]),
+ f32_to_f16_fallback(v[1]),
+ f32_to_f16_fallback(v[2]),
+ f32_to_f16_fallback(v[3]),
+ ]
+}
+
+#[inline]
+fn f16x4_to_f64x4_fallback(v: &[u16; 4]) -> [f64; 4] {
+ [
+ f16_to_f64_fallback(v[0]),
+ f16_to_f64_fallback(v[1]),
+ f16_to_f64_fallback(v[2]),
+ f16_to_f64_fallback(v[3]),
+ ]
+}
+
+#[inline]
+fn f64x4_to_f16x4_fallback(v: &[f64; 4]) -> [u16; 4] {
+ [
+ f64_to_f16_fallback(v[0]),
+ f64_to_f16_fallback(v[1]),
+ f64_to_f16_fallback(v[2]),
+ f64_to_f16_fallback(v[3]),
+ ]
+}
+
+#[inline]
+fn f16x8_to_f32x8_fallback(v: &[u16; 8]) -> [f32; 8] {
+ [
+ f16_to_f32_fallback(v[0]),
+ f16_to_f32_fallback(v[1]),
+ f16_to_f32_fallback(v[2]),
+ f16_to_f32_fallback(v[3]),
+ f16_to_f32_fallback(v[4]),
+ f16_to_f32_fallback(v[5]),
+ f16_to_f32_fallback(v[6]),
+ f16_to_f32_fallback(v[7]),
+ ]
+}
+
+#[inline]
+fn f32x8_to_f16x8_fallback(v: &[f32; 8]) -> [u16; 8] {
+ [
+ f32_to_f16_fallback(v[0]),
+ f32_to_f16_fallback(v[1]),
+ f32_to_f16_fallback(v[2]),
+ f32_to_f16_fallback(v[3]),
+ f32_to_f16_fallback(v[4]),
+ f32_to_f16_fallback(v[5]),
+ f32_to_f16_fallback(v[6]),
+ f32_to_f16_fallback(v[7]),
+ ]
+}
+
+#[inline]
+fn f16x8_to_f64x8_fallback(v: &[u16; 8]) -> [f64; 8] {
+ [
+ f16_to_f64_fallback(v[0]),
+ f16_to_f64_fallback(v[1]),
+ f16_to_f64_fallback(v[2]),
+ f16_to_f64_fallback(v[3]),
+ f16_to_f64_fallback(v[4]),
+ f16_to_f64_fallback(v[5]),
+ f16_to_f64_fallback(v[6]),
+ f16_to_f64_fallback(v[7]),
+ ]
+}
+
+#[inline]
+fn f64x8_to_f16x8_fallback(v: &[f64; 8]) -> [u16; 8] {
+ [
+ f64_to_f16_fallback(v[0]),
+ f64_to_f16_fallback(v[1]),
+ f64_to_f16_fallback(v[2]),
+ f64_to_f16_fallback(v[3]),
+ f64_to_f16_fallback(v[4]),
+ f64_to_f16_fallback(v[5]),
+ f64_to_f16_fallback(v[6]),
+ f64_to_f16_fallback(v[7]),
+ ]
+}
+
+#[inline]
+fn slice_fallback<S: Copy, D>(src: &[S], dst: &mut [D], f: fn(S) -> D) {
+ assert_eq!(src.len(), dst.len());
+ for (s, d) in src.iter().copied().zip(dst.iter_mut()) {
+ *d = f(s);
+ }
+}
+
+/////////////// x86/x86_64 f16c ////////////////
+#[cfg(all(
+ feature = "use-intrinsics",
+ any(target_arch = "x86", target_arch = "x86_64")
+))]
+mod x86 {
+ use core::{mem::MaybeUninit, ptr};
+
+ #[cfg(target_arch = "x86")]
+ use core::arch::x86::{
+ __m128, __m128i, __m256, _mm256_cvtph_ps, _mm256_cvtps_ph, _mm_cvtph_ps,
+ _MM_FROUND_TO_NEAREST_INT,
+ };
+ #[cfg(target_arch = "x86_64")]
+ use core::arch::x86_64::{
+ __m128, __m128i, __m256, _mm256_cvtph_ps, _mm256_cvtps_ph, _mm_cvtph_ps, _mm_cvtps_ph,
+ _MM_FROUND_TO_NEAREST_INT,
+ };
+
+ use super::convert_chunked_slice_8;
+
+ #[target_feature(enable = "f16c")]
+ #[inline]
+ pub(super) unsafe fn f16_to_f32_x86_f16c(i: u16) -> f32 {
+ let mut vec = MaybeUninit::<__m128i>::zeroed();
+ vec.as_mut_ptr().cast::<u16>().write(i);
+ let retval = _mm_cvtph_ps(vec.assume_init());
+ *(&retval as *const __m128).cast()
+ }
+
+ #[target_feature(enable = "f16c")]
+ #[inline]
+ pub(super) unsafe fn f32_to_f16_x86_f16c(f: f32) -> u16 {
+ let mut vec = MaybeUninit::<__m128>::zeroed();
+ vec.as_mut_ptr().cast::<f32>().write(f);
+ let retval = _mm_cvtps_ph(vec.assume_init(), _MM_FROUND_TO_NEAREST_INT);
+ *(&retval as *const __m128i).cast()
+ }
+
+ #[target_feature(enable = "f16c")]
+ #[inline]
+ pub(super) unsafe fn f16x4_to_f32x4_x86_f16c(v: &[u16; 4]) -> [f32; 4] {
+ let mut vec = MaybeUninit::<__m128i>::zeroed();
+ ptr::copy_nonoverlapping(v.as_ptr(), vec.as_mut_ptr().cast(), 4);
+ let retval = _mm_cvtph_ps(vec.assume_init());
+ *(&retval as *const __m128).cast()
+ }
+
+ #[target_feature(enable = "f16c")]
+ #[inline]
+ pub(super) unsafe fn f32x4_to_f16x4_x86_f16c(v: &[f32; 4]) -> [u16; 4] {
+ let mut vec = MaybeUninit::<__m128>::uninit();
+ ptr::copy_nonoverlapping(v.as_ptr(), vec.as_mut_ptr().cast(), 4);
+ let retval = _mm_cvtps_ph(vec.assume_init(), _MM_FROUND_TO_NEAREST_INT);
+ *(&retval as *const __m128i).cast()
+ }
+
+ #[target_feature(enable = "f16c")]
+ #[inline]
+ pub(super) unsafe fn f16x4_to_f64x4_x86_f16c(v: &[u16; 4]) -> [f64; 4] {
+ let array = f16x4_to_f32x4_x86_f16c(v);
+ // Let compiler vectorize this regular cast for now.
+ // TODO: investigate auto-detecting sse2/avx convert features
+ [
+ array[0] as f64,
+ array[1] as f64,
+ array[2] as f64,
+ array[3] as f64,
+ ]
+ }
+
+ #[target_feature(enable = "f16c")]
+ #[inline]
+ pub(super) unsafe fn f64x4_to_f16x4_x86_f16c(v: &[f64; 4]) -> [u16; 4] {
+ // Let compiler vectorize this regular cast for now.
+ // TODO: investigate auto-detecting sse2/avx convert features
+ let v = [v[0] as f32, v[1] as f32, v[2] as f32, v[3] as f32];
+ f32x4_to_f16x4_x86_f16c(&v)
+ }
+
+ #[target_feature(enable = "f16c")]
+ #[inline]
+ pub(super) unsafe fn f16x8_to_f32x8_x86_f16c(v: &[u16; 8]) -> [f32; 8] {
+ let mut vec = MaybeUninit::<__m128i>::zeroed();
+ ptr::copy_nonoverlapping(v.as_ptr(), vec.as_mut_ptr().cast(), 8);
+ let retval = _mm256_cvtph_ps(vec.assume_init());
+ *(&retval as *const __m256).cast()
+ }
+
+ #[target_feature(enable = "f16c")]
+ #[inline]
+ pub(super) unsafe fn f32x8_to_f16x8_x86_f16c(v: &[f32; 8]) -> [u16; 8] {
+ let mut vec = MaybeUninit::<__m256>::uninit();
+ ptr::copy_nonoverlapping(v.as_ptr(), vec.as_mut_ptr().cast(), 8);
+ let retval = _mm256_cvtps_ph(vec.assume_init(), _MM_FROUND_TO_NEAREST_INT);
+ *(&retval as *const __m128i).cast()
+ }
+
+ #[target_feature(enable = "f16c")]
+ #[inline]
+ pub(super) unsafe fn f16x8_to_f64x8_x86_f16c(v: &[u16; 8]) -> [f64; 8] {
+ let array = f16x8_to_f32x8_x86_f16c(v);
+ // Let compiler vectorize this regular cast for now.
+ // TODO: investigate auto-detecting sse2/avx convert features
+ [
+ array[0] as f64,
+ array[1] as f64,
+ array[2] as f64,
+ array[3] as f64,
+ array[4] as f64,
+ array[5] as f64,
+ array[6] as f64,
+ array[7] as f64,
+ ]
+ }
+
+ #[target_feature(enable = "f16c")]
+ #[inline]
+ pub(super) unsafe fn f64x8_to_f16x8_x86_f16c(v: &[f64; 8]) -> [u16; 8] {
+ // Let compiler vectorize this regular cast for now.
+ // TODO: investigate auto-detecting sse2/avx convert features
+ let v = [
+ v[0] as f32,
+ v[1] as f32,
+ v[2] as f32,
+ v[3] as f32,
+ v[4] as f32,
+ v[5] as f32,
+ v[6] as f32,
+ v[7] as f32,
+ ];
+ f32x8_to_f16x8_x86_f16c(&v)
+ }
+}
--- /dev/null
+// https://doc.rust-lang.org/std/primitive.u16.html#method.leading_zeros
+
+#[cfg(not(any(all(
+ target_arch = "spirv",
+ not(all(
+ target_feature = "IntegerFunctions2INTEL",
+ target_feature = "SPV_INTEL_shader_integer_functions2"
+ ))
+))))]
+pub(crate) const fn leading_zeros_u16(x: u16) -> u32 {
+ x.leading_zeros()
+}
+
+#[cfg(all(
+ target_arch = "spirv",
+ not(all(
+ target_feature = "IntegerFunctions2INTEL",
+ target_feature = "SPV_INTEL_shader_integer_functions2"
+ ))
+))]
+pub(crate) const fn leading_zeros_u16(x: u16) -> u32 {
+ leading_zeros_u16_fallback(x)
+}
+
+#[cfg(any(
+ test,
+ all(
+ target_arch = "spirv",
+ not(all(
+ target_feature = "IntegerFunctions2INTEL",
+ target_feature = "SPV_INTEL_shader_integer_functions2"
+ ))
+ )
+))]
+const fn leading_zeros_u16_fallback(mut x: u16) -> u32 {
+ use crunchy::unroll;
+ let mut c = 0;
+ let msb = 1 << 15;
+ unroll! { for i in 0 .. 16 {
+ if x & msb == 0 {
+ c += 1;
+ } else {
+ return c;
+ }
+ #[allow(unused_assignments)]
+ if i < 15 {
+ x <<= 1;
+ }
+ }}
+ c
+}
+
+#[cfg(test)]
+mod test {
+
+ #[test]
+ fn leading_zeros_u16_fallback() {
+ for x in [44, 97, 304, 1179, 23571] {
+ assert_eq!(super::leading_zeros_u16_fallback(x), x.leading_zeros());
+ }
+ }
+}
--- /dev/null
+//! A crate that provides support for half-precision 16-bit floating point types.
+//!
+//! This crate provides the [`f16`] type, which is an implementation of the IEEE 754-2008 standard
+//! [`binary16`] a.k.a `half` floating point type. This 16-bit floating point type is intended for
+//! efficient storage where the full range and precision of a larger floating point value is not
+//! required. This is especially useful for image storage formats.
+//!
+//! This crate also provides a [`bf16`] type, an alternative 16-bit floating point format. The
+//! [`bfloat16`] format is a truncated IEEE 754 standard `binary32` float that preserves the
+//! exponent to allow the same range as [`f32`] but with only 8 bits of precision (instead of 11
+//! bits for [`f16`]). See the [`bf16`] type for details.
+//!
+//! Because [`f16`] and [`bf16`] are primarily for efficient storage, floating point operations such
+//! as addition, multiplication, etc. are not implemented by hardware. While this crate does provide
+//! the appropriate trait implementations for basic operations, they each convert the value to
+//! [`f32`] before performing the operation and then back afterward. When performing complex
+//! arithmetic, manually convert to and from [`f32`] before and after to reduce repeated conversions
+//! for each operation.
+//!
+//! This crate also provides a [`slice`][mod@slice] module for zero-copy in-place conversions of
+//! [`u16`] slices to both [`f16`] and [`bf16`], as well as efficient vectorized conversions of
+//! larger buffers of floating point values to and from these half formats.
+//!
+//! The crate uses `#[no_std]` by default, so can be used in embedded environments without using the
+//! Rust [`std`] library. A `std` feature to enable support for the standard library is available,
+//! see the [Cargo Features](#cargo-features) section below.
+//!
+//! A [`prelude`] module is provided for easy importing of available utility traits.
+//!
+//! # Serialization
+//!
+//! When the `serde` feature is enabled, [`f16`] and [`bf16`] will be serialized as a newtype of
+//! [`u16`] by default. In binary formats this is ideal, as it will generally use just two bytes for
+//! storage. For string formats like JSON, however, this isn't as useful, and due to design
+//! limitations of serde, it's not possible for the default `Serialize` implementation to support
+//! different serialization for different formats.
+//!
+//! Instead, it's up to the containter type of the floats to control how it is serialized. This can
+//! easily be controlled when using the derive macros using `#[serde(serialize_with="")]`
+//! attributes. For both [`f16`] and [`bf16`] a `serialize_as_f32` and `serialize_as_string` are
+//! provided for use with this attribute.
+//!
+//! Deserialization of both float types supports deserializing from the default serialization,
+//! strings, and `f32`/`f64` values, so no additional work is required.
+//!
+//! # Cargo Features
+//!
+//! This crate supports a number of optional cargo features. None of these features are enabled by
+//! default, even `std`.
+//!
+//! - **`use-intrinsics`** -- Use [`core::arch`] hardware intrinsics for `f16` and `bf16` conversions
+//! if available on the compiler target. This feature currently only works on nightly Rust
+//! until the corresponding intrinsics are stabilized.
+//!
+//! When this feature is enabled and the hardware supports it, the functions and traits in the
+//! [`slice`][mod@slice] module will use vectorized SIMD intructions for increased efficiency.
+//!
+//! By default, without this feature, conversions are done only in software, which will also be
+//! the fallback if the target does not have hardware support. Note that without the `std`
+//! feature enabled, no runtime CPU feature detection is used, so the hardware support is only
+//! compiled if the compiler target supports the CPU feature.
+//!
+//! - **`alloc`** -- Enable use of the [`alloc`] crate when not using the `std` library.
+//!
+//! Among other functions, this enables the [`vec`] module, which contains zero-copy
+//! conversions for the [`Vec`] type. This allows fast conversion between raw `Vec<u16>` bits and
+//! `Vec<f16>` or `Vec<bf16>` arrays, and vice versa.
+//!
+//! - **`std`** -- Enable features that depend on the Rust [`std`] library. This also enables the
+//! `alloc` feature automatically.
+//!
+//! Enabling the `std` feature also enables runtime CPU feature detection when the
+//! `use-intrsincis` feature is also enabled. Without this feature detection, intrinsics are only
+//! used when compiler target supports the target feature.
+//!
+//! - **`serde`** -- Adds support for the [`serde`] crate by implementing [`Serialize`] and
+//! [`Deserialize`] traits for both [`f16`] and [`bf16`].
+//!
+//! - **`num-traits`** -- Adds support for the [`num-traits`] crate by implementing [`ToPrimitive`],
+//! [`FromPrimitive`], [`AsPrimitive`], [`Num`], [`Float`], [`FloatCore`], and [`Bounded`] traits
+//! for both [`f16`] and [`bf16`].
+//!
+//! - **`bytemuck`** -- Adds support for the [`bytemuck`] crate by implementing [`Zeroable`] and
+//! [`Pod`] traits for both [`f16`] and [`bf16`].
+//!
+//! - **`zerocopy`** -- Adds support for the [`zerocopy`] crate by implementing [`AsBytes`] and
+//! [`FromBytes`] traits for both [`f16`] and [`bf16`].
+//!
+//! [`alloc`]: https://doc.rust-lang.org/alloc/
+//! [`std`]: https://doc.rust-lang.org/std/
+//! [`binary16`]: https://en.wikipedia.org/wiki/Half-precision_floating-point_format
+//! [`bfloat16`]: https://en.wikipedia.org/wiki/Bfloat16_floating-point_format
+//! [`serde`]: https://crates.io/crates/serde
+//! [`bytemuck`]: https://crates.io/crates/bytemuck
+//! [`num-traits`]: https://crates.io/crates/num-traits
+//! [`zerocopy`]: https://crates.io/crates/zerocopy
+#![cfg_attr(
+ feature = "alloc",
+ doc = "
+[`vec`]: mod@vec"
+)]
+#![cfg_attr(
+ not(feature = "alloc"),
+ doc = "
+[`vec`]: #
+[`Vec`]: https://docs.rust-lang.org/stable/alloc/vec/struct.Vec.html"
+)]
+#![cfg_attr(
+ feature = "serde",
+ doc = "
+[`Serialize`]: serde::Serialize
+[`Deserialize`]: serde::Deserialize"
+)]
+#![cfg_attr(
+ not(feature = "serde"),
+ doc = "
+[`Serialize`]: https://docs.rs/serde/*/serde/trait.Serialize.html
+[`Deserialize`]: https://docs.rs/serde/*/serde/trait.Deserialize.html"
+)]
+#![cfg_attr(
+ feature = "num-traits",
+ doc = "
+[`ToPrimitive`]: ::num_traits::ToPrimitive
+[`FromPrimitive`]: ::num_traits::FromPrimitive
+[`AsPrimitive`]: ::num_traits::AsPrimitive
+[`Num`]: ::num_traits::Num
+[`Float`]: ::num_traits::Float
+[`FloatCore`]: ::num_traits::float::FloatCore
+[`Bounded`]: ::num_traits::Bounded"
+)]
+#![cfg_attr(
+ not(feature = "num-traits"),
+ doc = "
+[`ToPrimitive`]: https://docs.rs/num-traits/*/num_traits/cast/trait.ToPrimitive.html
+[`FromPrimitive`]: https://docs.rs/num-traits/*/num_traits/cast/trait.FromPrimitive.html
+[`AsPrimitive`]: https://docs.rs/num-traits/*/num_traits/cast/trait.AsPrimitive.html
+[`Num`]: https://docs.rs/num-traits/*/num_traits/trait.Num.html
+[`Float`]: https://docs.rs/num-traits/*/num_traits/float/trait.Float.html
+[`FloatCore`]: https://docs.rs/num-traits/*/num_traits/float/trait.FloatCore.html
+[`Bounded`]: https://docs.rs/num-traits/*/num_traits/bounds/trait.Bounded.html"
+)]
+#![cfg_attr(
+ feature = "bytemuck",
+ doc = "
+[`Zeroable`]: bytemuck::Zeroable
+[`Pod`]: bytemuck::Pod"
+)]
+#![cfg_attr(
+ not(feature = "bytemuck"),
+ doc = "
+[`Zeroable`]: https://docs.rs/bytemuck/*/bytemuck/trait.Zeroable.html
+[`Pod`]: https://docs.rs/bytemuck/*bytemuck/trait.Pod.html"
+)]
+#![cfg_attr(
+ feature = "zerocopy",
+ doc = "
+[`AsBytes`]: zerocopy::AsBytes
+[`FromBytes`]: zerocopy::FromBytes"
+)]
+#![cfg_attr(
+ not(feature = "zerocopy"),
+ doc = "
+[`AsBytes`]: https://docs.rs/zerocopy/*/zerocopy/trait.AsBytes.html
+[`FromBytes`]: https://docs.rs/zerocopy/*/zerocopy/trait.FromBytes.html"
+)]
+#![warn(
+ missing_docs,
+ missing_copy_implementations,
+ trivial_numeric_casts,
+ future_incompatible
+)]
+#![cfg_attr(not(target_arch = "spirv"), warn(missing_debug_implementations))]
+#![allow(clippy::verbose_bit_mask, clippy::cast_lossless)]
+#![cfg_attr(not(feature = "std"), no_std)]
+#![cfg_attr(
+ all(
+ feature = "use-intrinsics",
+ any(target_arch = "x86", target_arch = "x86_64")
+ ),
+ feature(stdsimd, f16c_target_feature)
+)]
+#![doc(html_root_url = "https://docs.rs/half/2.2.1")]
+#![doc(test(attr(deny(warnings), allow(unused))))]
+#![cfg_attr(docsrs, feature(doc_cfg))]
+
+#[cfg(feature = "alloc")]
+extern crate alloc;
+
+mod bfloat;
+mod binary16;
+mod leading_zeros;
+#[cfg(feature = "num-traits")]
+mod num_traits;
+
+#[cfg(not(target_arch = "spirv"))]
+pub mod slice;
+#[cfg(feature = "alloc")]
+#[cfg_attr(docsrs, doc(cfg(feature = "alloc")))]
+pub mod vec;
+
+pub use bfloat::bf16;
+pub use binary16::f16;
+
+/// A collection of the most used items and traits in this crate for easy importing.
+///
+/// # Examples
+///
+/// ```rust
+/// use half::prelude::*;
+/// ```
+pub mod prelude {
+ #[doc(no_inline)]
+ pub use crate::{bf16, f16};
+
+ #[cfg(not(target_arch = "spirv"))]
+ #[doc(no_inline)]
+ pub use crate::slice::{HalfBitsSliceExt, HalfFloatSliceExt};
+
+ #[cfg(feature = "alloc")]
+ #[doc(no_inline)]
+ #[cfg_attr(docsrs, doc(cfg(feature = "alloc")))]
+ pub use crate::vec::{HalfBitsVecExt, HalfFloatVecExt};
+}
+
+// Keep this module private to crate
+mod private {
+ use crate::{bf16, f16};
+
+ pub trait SealedHalf {}
+
+ impl SealedHalf for f16 {}
+ impl SealedHalf for bf16 {}
+}
--- /dev/null
+use crate::{bf16, f16};
+use core::cmp::Ordering;
+use core::{num::FpCategory, ops::Div};
+use num_traits::{
+ AsPrimitive, Bounded, FloatConst, FromPrimitive, Num, NumCast, One, ToPrimitive, Zero,
+};
+
+impl ToPrimitive for f16 {
+ #[inline]
+ fn to_i64(&self) -> Option<i64> {
+ Self::to_f32(*self).to_i64()
+ }
+ #[inline]
+ fn to_u64(&self) -> Option<u64> {
+ Self::to_f32(*self).to_u64()
+ }
+ #[inline]
+ fn to_i8(&self) -> Option<i8> {
+ Self::to_f32(*self).to_i8()
+ }
+ #[inline]
+ fn to_u8(&self) -> Option<u8> {
+ Self::to_f32(*self).to_u8()
+ }
+ #[inline]
+ fn to_i16(&self) -> Option<i16> {
+ Self::to_f32(*self).to_i16()
+ }
+ #[inline]
+ fn to_u16(&self) -> Option<u16> {
+ Self::to_f32(*self).to_u16()
+ }
+ #[inline]
+ fn to_i32(&self) -> Option<i32> {
+ Self::to_f32(*self).to_i32()
+ }
+ #[inline]
+ fn to_u32(&self) -> Option<u32> {
+ Self::to_f32(*self).to_u32()
+ }
+ #[inline]
+ fn to_f32(&self) -> Option<f32> {
+ Some(Self::to_f32(*self))
+ }
+ #[inline]
+ fn to_f64(&self) -> Option<f64> {
+ Some(Self::to_f64(*self))
+ }
+}
+
+impl FromPrimitive for f16 {
+ #[inline]
+ fn from_i64(n: i64) -> Option<Self> {
+ n.to_f32().map(Self::from_f32)
+ }
+ #[inline]
+ fn from_u64(n: u64) -> Option<Self> {
+ n.to_f32().map(Self::from_f32)
+ }
+ #[inline]
+ fn from_i8(n: i8) -> Option<Self> {
+ n.to_f32().map(Self::from_f32)
+ }
+ #[inline]
+ fn from_u8(n: u8) -> Option<Self> {
+ n.to_f32().map(Self::from_f32)
+ }
+ #[inline]
+ fn from_i16(n: i16) -> Option<Self> {
+ n.to_f32().map(Self::from_f32)
+ }
+ #[inline]
+ fn from_u16(n: u16) -> Option<Self> {
+ n.to_f32().map(Self::from_f32)
+ }
+ #[inline]
+ fn from_i32(n: i32) -> Option<Self> {
+ n.to_f32().map(Self::from_f32)
+ }
+ #[inline]
+ fn from_u32(n: u32) -> Option<Self> {
+ n.to_f32().map(Self::from_f32)
+ }
+ #[inline]
+ fn from_f32(n: f32) -> Option<Self> {
+ n.to_f32().map(Self::from_f32)
+ }
+ #[inline]
+ fn from_f64(n: f64) -> Option<Self> {
+ n.to_f64().map(Self::from_f64)
+ }
+}
+
+impl Num for f16 {
+ type FromStrRadixErr = <f32 as Num>::FromStrRadixErr;
+
+ #[inline]
+ fn from_str_radix(str: &str, radix: u32) -> Result<Self, Self::FromStrRadixErr> {
+ Ok(Self::from_f32(f32::from_str_radix(str, radix)?))
+ }
+}
+
+impl One for f16 {
+ #[inline]
+ fn one() -> Self {
+ Self::ONE
+ }
+}
+
+impl Zero for f16 {
+ #[inline]
+ fn zero() -> Self {
+ Self::ZERO
+ }
+
+ #[inline]
+ fn is_zero(&self) -> bool {
+ *self == Self::ZERO
+ }
+}
+
+impl NumCast for f16 {
+ #[inline]
+ fn from<T: ToPrimitive>(n: T) -> Option<Self> {
+ n.to_f32().map(Self::from_f32)
+ }
+}
+
+impl num_traits::float::FloatCore for f16 {
+ #[inline]
+ fn infinity() -> Self {
+ Self::INFINITY
+ }
+
+ #[inline]
+ fn neg_infinity() -> Self {
+ Self::NEG_INFINITY
+ }
+
+ #[inline]
+ fn nan() -> Self {
+ Self::NAN
+ }
+
+ #[inline]
+ fn neg_zero() -> Self {
+ Self::NEG_ZERO
+ }
+
+ #[inline]
+ fn min_value() -> Self {
+ Self::MIN
+ }
+
+ #[inline]
+ fn min_positive_value() -> Self {
+ Self::MIN_POSITIVE
+ }
+
+ #[inline]
+ fn epsilon() -> Self {
+ Self::EPSILON
+ }
+
+ #[inline]
+ fn max_value() -> Self {
+ Self::MAX
+ }
+
+ #[inline]
+ fn is_nan(self) -> bool {
+ self.is_nan()
+ }
+
+ #[inline]
+ fn is_infinite(self) -> bool {
+ self.is_infinite()
+ }
+
+ #[inline]
+ fn is_finite(self) -> bool {
+ self.is_finite()
+ }
+
+ #[inline]
+ fn is_normal(self) -> bool {
+ self.is_normal()
+ }
+
+ #[inline]
+ fn classify(self) -> FpCategory {
+ self.classify()
+ }
+
+ #[inline]
+ fn floor(self) -> Self {
+ Self::from_f32(self.to_f32().floor())
+ }
+
+ #[inline]
+ fn ceil(self) -> Self {
+ Self::from_f32(self.to_f32().ceil())
+ }
+
+ #[inline]
+ fn round(self) -> Self {
+ Self::from_f32(self.to_f32().round())
+ }
+
+ #[inline]
+ fn trunc(self) -> Self {
+ Self::from_f32(self.to_f32().trunc())
+ }
+
+ #[inline]
+ fn fract(self) -> Self {
+ Self::from_f32(self.to_f32().fract())
+ }
+
+ #[inline]
+ fn abs(self) -> Self {
+ Self::from_bits(self.to_bits() & 0x7FFF)
+ }
+
+ #[inline]
+ fn signum(self) -> Self {
+ self.signum()
+ }
+
+ #[inline]
+ fn is_sign_positive(self) -> bool {
+ self.is_sign_positive()
+ }
+
+ #[inline]
+ fn is_sign_negative(self) -> bool {
+ self.is_sign_negative()
+ }
+
+ fn min(self, other: Self) -> Self {
+ match self.partial_cmp(&other) {
+ None => {
+ if self.is_nan() {
+ other
+ } else {
+ self
+ }
+ }
+ Some(Ordering::Greater) | Some(Ordering::Equal) => other,
+ Some(Ordering::Less) => self,
+ }
+ }
+
+ fn max(self, other: Self) -> Self {
+ match self.partial_cmp(&other) {
+ None => {
+ if self.is_nan() {
+ other
+ } else {
+ self
+ }
+ }
+ Some(Ordering::Greater) | Some(Ordering::Equal) => self,
+ Some(Ordering::Less) => other,
+ }
+ }
+
+ #[inline]
+ fn recip(self) -> Self {
+ Self::from_f32(self.to_f32().recip())
+ }
+
+ #[inline]
+ fn powi(self, exp: i32) -> Self {
+ Self::from_f32(self.to_f32().powi(exp))
+ }
+
+ #[inline]
+ fn to_degrees(self) -> Self {
+ Self::from_f32(self.to_f32().to_degrees())
+ }
+
+ #[inline]
+ fn to_radians(self) -> Self {
+ Self::from_f32(self.to_f32().to_radians())
+ }
+
+ #[inline]
+ fn integer_decode(self) -> (u64, i16, i8) {
+ num_traits::float::FloatCore::integer_decode(self.to_f32())
+ }
+}
+
+impl num_traits::float::Float for f16 {
+ #[inline]
+ fn nan() -> Self {
+ Self::NAN
+ }
+
+ #[inline]
+ fn infinity() -> Self {
+ Self::INFINITY
+ }
+
+ #[inline]
+ fn neg_infinity() -> Self {
+ Self::NEG_INFINITY
+ }
+
+ #[inline]
+ fn neg_zero() -> Self {
+ Self::NEG_ZERO
+ }
+
+ #[inline]
+ fn min_value() -> Self {
+ Self::MIN
+ }
+
+ #[inline]
+ fn min_positive_value() -> Self {
+ Self::MIN_POSITIVE
+ }
+
+ #[inline]
+ fn epsilon() -> Self {
+ Self::EPSILON
+ }
+
+ #[inline]
+ fn max_value() -> Self {
+ Self::MAX
+ }
+
+ #[inline]
+ fn is_nan(self) -> bool {
+ self.is_nan()
+ }
+
+ #[inline]
+ fn is_infinite(self) -> bool {
+ self.is_infinite()
+ }
+
+ #[inline]
+ fn is_finite(self) -> bool {
+ self.is_finite()
+ }
+
+ #[inline]
+ fn is_normal(self) -> bool {
+ self.is_normal()
+ }
+
+ #[inline]
+ fn classify(self) -> FpCategory {
+ self.classify()
+ }
+
+ #[inline]
+ fn floor(self) -> Self {
+ Self::from_f32(self.to_f32().floor())
+ }
+
+ #[inline]
+ fn ceil(self) -> Self {
+ Self::from_f32(self.to_f32().ceil())
+ }
+
+ #[inline]
+ fn round(self) -> Self {
+ Self::from_f32(self.to_f32().round())
+ }
+
+ #[inline]
+ fn trunc(self) -> Self {
+ Self::from_f32(self.to_f32().trunc())
+ }
+
+ #[inline]
+ fn fract(self) -> Self {
+ Self::from_f32(self.to_f32().fract())
+ }
+
+ #[inline]
+ fn abs(self) -> Self {
+ Self::from_f32(self.to_f32().abs())
+ }
+
+ #[inline]
+ fn signum(self) -> Self {
+ Self::from_f32(self.to_f32().signum())
+ }
+
+ #[inline]
+ fn is_sign_positive(self) -> bool {
+ self.is_sign_positive()
+ }
+
+ #[inline]
+ fn is_sign_negative(self) -> bool {
+ self.is_sign_negative()
+ }
+
+ #[inline]
+ fn mul_add(self, a: Self, b: Self) -> Self {
+ Self::from_f32(self.to_f32().mul_add(a.to_f32(), b.to_f32()))
+ }
+
+ #[inline]
+ fn recip(self) -> Self {
+ Self::from_f32(self.to_f32().recip())
+ }
+
+ #[inline]
+ fn powi(self, n: i32) -> Self {
+ Self::from_f32(self.to_f32().powi(n))
+ }
+
+ #[inline]
+ fn powf(self, n: Self) -> Self {
+ Self::from_f32(self.to_f32().powf(n.to_f32()))
+ }
+
+ #[inline]
+ fn sqrt(self) -> Self {
+ Self::from_f32(self.to_f32().sqrt())
+ }
+
+ #[inline]
+ fn exp(self) -> Self {
+ Self::from_f32(self.to_f32().exp())
+ }
+
+ #[inline]
+ fn exp2(self) -> Self {
+ Self::from_f32(self.to_f32().exp2())
+ }
+
+ #[inline]
+ fn ln(self) -> Self {
+ Self::from_f32(self.to_f32().ln())
+ }
+
+ #[inline]
+ fn log(self, base: Self) -> Self {
+ Self::from_f32(self.to_f32().log(base.to_f32()))
+ }
+
+ #[inline]
+ fn log2(self) -> Self {
+ Self::from_f32(self.to_f32().log2())
+ }
+
+ #[inline]
+ fn log10(self) -> Self {
+ Self::from_f32(self.to_f32().log10())
+ }
+
+ #[inline]
+ fn to_degrees(self) -> Self {
+ Self::from_f32(self.to_f32().to_degrees())
+ }
+
+ #[inline]
+ fn to_radians(self) -> Self {
+ Self::from_f32(self.to_f32().to_radians())
+ }
+
+ #[inline]
+ fn max(self, other: Self) -> Self {
+ self.max(other)
+ }
+
+ #[inline]
+ fn min(self, other: Self) -> Self {
+ self.min(other)
+ }
+
+ #[inline]
+ fn abs_sub(self, other: Self) -> Self {
+ Self::from_f32((self.to_f32() - other.to_f32()).max(0.0))
+ }
+
+ #[inline]
+ fn cbrt(self) -> Self {
+ Self::from_f32(self.to_f32().cbrt())
+ }
+
+ #[inline]
+ fn hypot(self, other: Self) -> Self {
+ Self::from_f32(self.to_f32().hypot(other.to_f32()))
+ }
+
+ #[inline]
+ fn sin(self) -> Self {
+ Self::from_f32(self.to_f32().sin())
+ }
+
+ #[inline]
+ fn cos(self) -> Self {
+ Self::from_f32(self.to_f32().cos())
+ }
+
+ #[inline]
+ fn tan(self) -> Self {
+ Self::from_f32(self.to_f32().tan())
+ }
+
+ #[inline]
+ fn asin(self) -> Self {
+ Self::from_f32(self.to_f32().asin())
+ }
+
+ #[inline]
+ fn acos(self) -> Self {
+ Self::from_f32(self.to_f32().acos())
+ }
+
+ #[inline]
+ fn atan(self) -> Self {
+ Self::from_f32(self.to_f32().atan())
+ }
+
+ #[inline]
+ fn atan2(self, other: Self) -> Self {
+ Self::from_f32(self.to_f32().atan2(other.to_f32()))
+ }
+
+ #[inline]
+ fn sin_cos(self) -> (Self, Self) {
+ let (sin, cos) = self.to_f32().sin_cos();
+ (Self::from_f32(sin), Self::from_f32(cos))
+ }
+
+ #[inline]
+ fn exp_m1(self) -> Self {
+ Self::from_f32(self.to_f32().exp_m1())
+ }
+
+ #[inline]
+ fn ln_1p(self) -> Self {
+ Self::from_f32(self.to_f32().ln_1p())
+ }
+
+ #[inline]
+ fn sinh(self) -> Self {
+ Self::from_f32(self.to_f32().sinh())
+ }
+
+ #[inline]
+ fn cosh(self) -> Self {
+ Self::from_f32(self.to_f32().cosh())
+ }
+
+ #[inline]
+ fn tanh(self) -> Self {
+ Self::from_f32(self.to_f32().tanh())
+ }
+
+ #[inline]
+ fn asinh(self) -> Self {
+ Self::from_f32(self.to_f32().asinh())
+ }
+
+ #[inline]
+ fn acosh(self) -> Self {
+ Self::from_f32(self.to_f32().acosh())
+ }
+
+ #[inline]
+ fn atanh(self) -> Self {
+ Self::from_f32(self.to_f32().atanh())
+ }
+
+ #[inline]
+ fn integer_decode(self) -> (u64, i16, i8) {
+ num_traits::float::Float::integer_decode(self.to_f32())
+ }
+}
+
+impl FloatConst for f16 {
+ #[inline]
+ fn E() -> Self {
+ Self::E
+ }
+
+ #[inline]
+ fn FRAC_1_PI() -> Self {
+ Self::FRAC_1_PI
+ }
+
+ #[inline]
+ fn FRAC_1_SQRT_2() -> Self {
+ Self::FRAC_1_SQRT_2
+ }
+
+ #[inline]
+ fn FRAC_2_PI() -> Self {
+ Self::FRAC_2_PI
+ }
+
+ #[inline]
+ fn FRAC_2_SQRT_PI() -> Self {
+ Self::FRAC_2_SQRT_PI
+ }
+
+ #[inline]
+ fn FRAC_PI_2() -> Self {
+ Self::FRAC_PI_2
+ }
+
+ #[inline]
+ fn FRAC_PI_3() -> Self {
+ Self::FRAC_PI_3
+ }
+
+ #[inline]
+ fn FRAC_PI_4() -> Self {
+ Self::FRAC_PI_4
+ }
+
+ #[inline]
+ fn FRAC_PI_6() -> Self {
+ Self::FRAC_PI_6
+ }
+
+ #[inline]
+ fn FRAC_PI_8() -> Self {
+ Self::FRAC_PI_8
+ }
+
+ #[inline]
+ fn LN_10() -> Self {
+ Self::LN_10
+ }
+
+ #[inline]
+ fn LN_2() -> Self {
+ Self::LN_2
+ }
+
+ #[inline]
+ fn LOG10_E() -> Self {
+ Self::LOG10_E
+ }
+
+ #[inline]
+ fn LOG2_E() -> Self {
+ Self::LOG2_E
+ }
+
+ #[inline]
+ fn PI() -> Self {
+ Self::PI
+ }
+
+ fn SQRT_2() -> Self {
+ Self::SQRT_2
+ }
+
+ #[inline]
+ fn LOG10_2() -> Self
+ where
+ Self: Sized + Div<Self, Output = Self>,
+ {
+ Self::LOG10_2
+ }
+
+ #[inline]
+ fn LOG2_10() -> Self
+ where
+ Self: Sized + Div<Self, Output = Self>,
+ {
+ Self::LOG2_10
+ }
+}
+
+impl Bounded for f16 {
+ #[inline]
+ fn min_value() -> Self {
+ f16::MIN
+ }
+
+ #[inline]
+ fn max_value() -> Self {
+ f16::MAX
+ }
+}
+
+macro_rules! impl_as_primitive_to_f16 {
+ ($ty:ty, $meth:ident) => {
+ impl AsPrimitive<$ty> for f16 {
+ #[inline]
+ fn as_(self) -> $ty {
+ self.$meth().as_()
+ }
+ }
+ };
+}
+
+impl AsPrimitive<f16> for f16 {
+ #[inline]
+ fn as_(self) -> f16 {
+ self
+ }
+}
+
+impl_as_primitive_to_f16!(i64, to_f32);
+impl_as_primitive_to_f16!(u64, to_f32);
+impl_as_primitive_to_f16!(i8, to_f32);
+impl_as_primitive_to_f16!(u8, to_f32);
+impl_as_primitive_to_f16!(i16, to_f32);
+impl_as_primitive_to_f16!(u16, to_f32);
+impl_as_primitive_to_f16!(i32, to_f32);
+impl_as_primitive_to_f16!(u32, to_f32);
+impl_as_primitive_to_f16!(isize, to_f32);
+impl_as_primitive_to_f16!(usize, to_f32);
+impl_as_primitive_to_f16!(f32, to_f32);
+impl_as_primitive_to_f16!(f64, to_f64);
+
+macro_rules! impl_as_primitive_f16_from {
+ ($ty:ty, $meth:ident) => {
+ impl AsPrimitive<f16> for $ty {
+ #[inline]
+ fn as_(self) -> f16 {
+ f16::$meth(self.as_())
+ }
+ }
+ };
+}
+
+impl_as_primitive_f16_from!(i64, from_f32);
+impl_as_primitive_f16_from!(u64, from_f32);
+impl_as_primitive_f16_from!(i8, from_f32);
+impl_as_primitive_f16_from!(u8, from_f32);
+impl_as_primitive_f16_from!(i16, from_f32);
+impl_as_primitive_f16_from!(u16, from_f32);
+impl_as_primitive_f16_from!(i32, from_f32);
+impl_as_primitive_f16_from!(u32, from_f32);
+impl_as_primitive_f16_from!(isize, from_f32);
+impl_as_primitive_f16_from!(usize, from_f32);
+impl_as_primitive_f16_from!(f32, from_f32);
+impl_as_primitive_f16_from!(f64, from_f64);
+
+impl ToPrimitive for bf16 {
+ #[inline]
+ fn to_i64(&self) -> Option<i64> {
+ Self::to_f32(*self).to_i64()
+ }
+ #[inline]
+ fn to_u64(&self) -> Option<u64> {
+ Self::to_f32(*self).to_u64()
+ }
+ #[inline]
+ fn to_i8(&self) -> Option<i8> {
+ Self::to_f32(*self).to_i8()
+ }
+ #[inline]
+ fn to_u8(&self) -> Option<u8> {
+ Self::to_f32(*self).to_u8()
+ }
+ #[inline]
+ fn to_i16(&self) -> Option<i16> {
+ Self::to_f32(*self).to_i16()
+ }
+ #[inline]
+ fn to_u16(&self) -> Option<u16> {
+ Self::to_f32(*self).to_u16()
+ }
+ #[inline]
+ fn to_i32(&self) -> Option<i32> {
+ Self::to_f32(*self).to_i32()
+ }
+ #[inline]
+ fn to_u32(&self) -> Option<u32> {
+ Self::to_f32(*self).to_u32()
+ }
+ #[inline]
+ fn to_f32(&self) -> Option<f32> {
+ Some(Self::to_f32(*self))
+ }
+ #[inline]
+ fn to_f64(&self) -> Option<f64> {
+ Some(Self::to_f64(*self))
+ }
+}
+
+impl FromPrimitive for bf16 {
+ #[inline]
+ fn from_i64(n: i64) -> Option<Self> {
+ n.to_f32().map(Self::from_f32)
+ }
+ #[inline]
+ fn from_u64(n: u64) -> Option<Self> {
+ n.to_f32().map(Self::from_f32)
+ }
+ #[inline]
+ fn from_i8(n: i8) -> Option<Self> {
+ n.to_f32().map(Self::from_f32)
+ }
+ #[inline]
+ fn from_u8(n: u8) -> Option<Self> {
+ n.to_f32().map(Self::from_f32)
+ }
+ #[inline]
+ fn from_i16(n: i16) -> Option<Self> {
+ n.to_f32().map(Self::from_f32)
+ }
+ #[inline]
+ fn from_u16(n: u16) -> Option<Self> {
+ n.to_f32().map(Self::from_f32)
+ }
+ #[inline]
+ fn from_i32(n: i32) -> Option<Self> {
+ n.to_f32().map(Self::from_f32)
+ }
+ #[inline]
+ fn from_u32(n: u32) -> Option<Self> {
+ n.to_f32().map(Self::from_f32)
+ }
+ #[inline]
+ fn from_f32(n: f32) -> Option<Self> {
+ n.to_f32().map(Self::from_f32)
+ }
+ #[inline]
+ fn from_f64(n: f64) -> Option<Self> {
+ n.to_f64().map(Self::from_f64)
+ }
+}
+
+impl Num for bf16 {
+ type FromStrRadixErr = <f32 as Num>::FromStrRadixErr;
+
+ #[inline]
+ fn from_str_radix(str: &str, radix: u32) -> Result<Self, Self::FromStrRadixErr> {
+ Ok(Self::from_f32(f32::from_str_radix(str, radix)?))
+ }
+}
+
+impl One for bf16 {
+ #[inline]
+ fn one() -> Self {
+ Self::ONE
+ }
+}
+
+impl Zero for bf16 {
+ #[inline]
+ fn zero() -> Self {
+ Self::ZERO
+ }
+
+ #[inline]
+ fn is_zero(&self) -> bool {
+ *self == Self::ZERO
+ }
+}
+
+impl NumCast for bf16 {
+ #[inline]
+ fn from<T: ToPrimitive>(n: T) -> Option<Self> {
+ n.to_f32().map(Self::from_f32)
+ }
+}
+
+impl num_traits::float::FloatCore for bf16 {
+ #[inline]
+ fn infinity() -> Self {
+ Self::INFINITY
+ }
+
+ #[inline]
+ fn neg_infinity() -> Self {
+ Self::NEG_INFINITY
+ }
+
+ #[inline]
+ fn nan() -> Self {
+ Self::NAN
+ }
+
+ #[inline]
+ fn neg_zero() -> Self {
+ Self::NEG_ZERO
+ }
+
+ #[inline]
+ fn min_value() -> Self {
+ Self::MIN
+ }
+
+ #[inline]
+ fn min_positive_value() -> Self {
+ Self::MIN_POSITIVE
+ }
+
+ #[inline]
+ fn epsilon() -> Self {
+ Self::EPSILON
+ }
+
+ #[inline]
+ fn max_value() -> Self {
+ Self::MAX
+ }
+
+ #[inline]
+ fn is_nan(self) -> bool {
+ self.is_nan()
+ }
+
+ #[inline]
+ fn is_infinite(self) -> bool {
+ self.is_infinite()
+ }
+
+ #[inline]
+ fn is_finite(self) -> bool {
+ self.is_finite()
+ }
+
+ #[inline]
+ fn is_normal(self) -> bool {
+ self.is_normal()
+ }
+
+ #[inline]
+ fn classify(self) -> FpCategory {
+ self.classify()
+ }
+
+ #[inline]
+ fn floor(self) -> Self {
+ Self::from_f32(self.to_f32().floor())
+ }
+
+ #[inline]
+ fn ceil(self) -> Self {
+ Self::from_f32(self.to_f32().ceil())
+ }
+
+ #[inline]
+ fn round(self) -> Self {
+ Self::from_f32(self.to_f32().round())
+ }
+
+ #[inline]
+ fn trunc(self) -> Self {
+ Self::from_f32(self.to_f32().trunc())
+ }
+
+ #[inline]
+ fn fract(self) -> Self {
+ Self::from_f32(self.to_f32().fract())
+ }
+
+ #[inline]
+ fn abs(self) -> Self {
+ Self::from_bits(self.to_bits() & 0x7FFF)
+ }
+
+ #[inline]
+ fn signum(self) -> Self {
+ self.signum()
+ }
+
+ #[inline]
+ fn is_sign_positive(self) -> bool {
+ self.is_sign_positive()
+ }
+
+ #[inline]
+ fn is_sign_negative(self) -> bool {
+ self.is_sign_negative()
+ }
+
+ fn min(self, other: Self) -> Self {
+ match self.partial_cmp(&other) {
+ None => {
+ if self.is_nan() {
+ other
+ } else {
+ self
+ }
+ }
+ Some(Ordering::Greater) | Some(Ordering::Equal) => other,
+ Some(Ordering::Less) => self,
+ }
+ }
+
+ fn max(self, other: Self) -> Self {
+ match self.partial_cmp(&other) {
+ None => {
+ if self.is_nan() {
+ other
+ } else {
+ self
+ }
+ }
+ Some(Ordering::Greater) | Some(Ordering::Equal) => self,
+ Some(Ordering::Less) => other,
+ }
+ }
+
+ #[inline]
+ fn recip(self) -> Self {
+ Self::from_f32(self.to_f32().recip())
+ }
+
+ #[inline]
+ fn powi(self, exp: i32) -> Self {
+ Self::from_f32(self.to_f32().powi(exp))
+ }
+
+ #[inline]
+ fn to_degrees(self) -> Self {
+ Self::from_f32(self.to_f32().to_degrees())
+ }
+
+ #[inline]
+ fn to_radians(self) -> Self {
+ Self::from_f32(self.to_f32().to_radians())
+ }
+
+ #[inline]
+ fn integer_decode(self) -> (u64, i16, i8) {
+ num_traits::float::FloatCore::integer_decode(self.to_f32())
+ }
+}
+
+impl num_traits::float::Float for bf16 {
+ #[inline]
+ fn nan() -> Self {
+ Self::NAN
+ }
+
+ #[inline]
+ fn infinity() -> Self {
+ Self::INFINITY
+ }
+
+ #[inline]
+ fn neg_infinity() -> Self {
+ Self::NEG_INFINITY
+ }
+
+ #[inline]
+ fn neg_zero() -> Self {
+ Self::NEG_ZERO
+ }
+
+ #[inline]
+ fn min_value() -> Self {
+ Self::MIN
+ }
+
+ #[inline]
+ fn min_positive_value() -> Self {
+ Self::MIN_POSITIVE
+ }
+
+ #[inline]
+ fn epsilon() -> Self {
+ Self::EPSILON
+ }
+
+ #[inline]
+ fn max_value() -> Self {
+ Self::MAX
+ }
+
+ #[inline]
+ fn is_nan(self) -> bool {
+ self.is_nan()
+ }
+
+ #[inline]
+ fn is_infinite(self) -> bool {
+ self.is_infinite()
+ }
+
+ #[inline]
+ fn is_finite(self) -> bool {
+ self.is_finite()
+ }
+
+ #[inline]
+ fn is_normal(self) -> bool {
+ self.is_normal()
+ }
+
+ #[inline]
+ fn classify(self) -> FpCategory {
+ self.classify()
+ }
+
+ #[inline]
+ fn floor(self) -> Self {
+ Self::from_f32(self.to_f32().floor())
+ }
+
+ #[inline]
+ fn ceil(self) -> Self {
+ Self::from_f32(self.to_f32().ceil())
+ }
+
+ #[inline]
+ fn round(self) -> Self {
+ Self::from_f32(self.to_f32().round())
+ }
+
+ #[inline]
+ fn trunc(self) -> Self {
+ Self::from_f32(self.to_f32().trunc())
+ }
+
+ #[inline]
+ fn fract(self) -> Self {
+ Self::from_f32(self.to_f32().fract())
+ }
+
+ #[inline]
+ fn abs(self) -> Self {
+ Self::from_f32(self.to_f32().abs())
+ }
+
+ #[inline]
+ fn signum(self) -> Self {
+ Self::from_f32(self.to_f32().signum())
+ }
+
+ #[inline]
+ fn is_sign_positive(self) -> bool {
+ self.is_sign_positive()
+ }
+
+ #[inline]
+ fn is_sign_negative(self) -> bool {
+ self.is_sign_negative()
+ }
+
+ #[inline]
+ fn mul_add(self, a: Self, b: Self) -> Self {
+ Self::from_f32(self.to_f32().mul_add(a.to_f32(), b.to_f32()))
+ }
+
+ #[inline]
+ fn recip(self) -> Self {
+ Self::from_f32(self.to_f32().recip())
+ }
+
+ #[inline]
+ fn powi(self, n: i32) -> Self {
+ Self::from_f32(self.to_f32().powi(n))
+ }
+
+ #[inline]
+ fn powf(self, n: Self) -> Self {
+ Self::from_f32(self.to_f32().powf(n.to_f32()))
+ }
+
+ #[inline]
+ fn sqrt(self) -> Self {
+ Self::from_f32(self.to_f32().sqrt())
+ }
+
+ #[inline]
+ fn exp(self) -> Self {
+ Self::from_f32(self.to_f32().exp())
+ }
+
+ #[inline]
+ fn exp2(self) -> Self {
+ Self::from_f32(self.to_f32().exp2())
+ }
+
+ #[inline]
+ fn ln(self) -> Self {
+ Self::from_f32(self.to_f32().ln())
+ }
+
+ #[inline]
+ fn log(self, base: Self) -> Self {
+ Self::from_f32(self.to_f32().log(base.to_f32()))
+ }
+
+ #[inline]
+ fn log2(self) -> Self {
+ Self::from_f32(self.to_f32().log2())
+ }
+
+ #[inline]
+ fn log10(self) -> Self {
+ Self::from_f32(self.to_f32().log10())
+ }
+
+ #[inline]
+ fn to_degrees(self) -> Self {
+ Self::from_f32(self.to_f32().to_degrees())
+ }
+
+ #[inline]
+ fn to_radians(self) -> Self {
+ Self::from_f32(self.to_f32().to_radians())
+ }
+
+ #[inline]
+ fn max(self, other: Self) -> Self {
+ self.max(other)
+ }
+
+ #[inline]
+ fn min(self, other: Self) -> Self {
+ self.min(other)
+ }
+
+ #[inline]
+ fn abs_sub(self, other: Self) -> Self {
+ Self::from_f32((self.to_f32() - other.to_f32()).max(0.0))
+ }
+
+ #[inline]
+ fn cbrt(self) -> Self {
+ Self::from_f32(self.to_f32().cbrt())
+ }
+
+ #[inline]
+ fn hypot(self, other: Self) -> Self {
+ Self::from_f32(self.to_f32().hypot(other.to_f32()))
+ }
+
+ #[inline]
+ fn sin(self) -> Self {
+ Self::from_f32(self.to_f32().sin())
+ }
+
+ #[inline]
+ fn cos(self) -> Self {
+ Self::from_f32(self.to_f32().cos())
+ }
+
+ #[inline]
+ fn tan(self) -> Self {
+ Self::from_f32(self.to_f32().tan())
+ }
+
+ #[inline]
+ fn asin(self) -> Self {
+ Self::from_f32(self.to_f32().asin())
+ }
+
+ #[inline]
+ fn acos(self) -> Self {
+ Self::from_f32(self.to_f32().acos())
+ }
+
+ #[inline]
+ fn atan(self) -> Self {
+ Self::from_f32(self.to_f32().atan())
+ }
+
+ #[inline]
+ fn atan2(self, other: Self) -> Self {
+ Self::from_f32(self.to_f32().atan2(other.to_f32()))
+ }
+
+ #[inline]
+ fn sin_cos(self) -> (Self, Self) {
+ let (sin, cos) = self.to_f32().sin_cos();
+ (Self::from_f32(sin), Self::from_f32(cos))
+ }
+
+ #[inline]
+ fn exp_m1(self) -> Self {
+ Self::from_f32(self.to_f32().exp_m1())
+ }
+
+ #[inline]
+ fn ln_1p(self) -> Self {
+ Self::from_f32(self.to_f32().ln_1p())
+ }
+
+ #[inline]
+ fn sinh(self) -> Self {
+ Self::from_f32(self.to_f32().sinh())
+ }
+
+ #[inline]
+ fn cosh(self) -> Self {
+ Self::from_f32(self.to_f32().cosh())
+ }
+
+ #[inline]
+ fn tanh(self) -> Self {
+ Self::from_f32(self.to_f32().tanh())
+ }
+
+ #[inline]
+ fn asinh(self) -> Self {
+ Self::from_f32(self.to_f32().asinh())
+ }
+
+ #[inline]
+ fn acosh(self) -> Self {
+ Self::from_f32(self.to_f32().acosh())
+ }
+
+ #[inline]
+ fn atanh(self) -> Self {
+ Self::from_f32(self.to_f32().atanh())
+ }
+
+ #[inline]
+ fn integer_decode(self) -> (u64, i16, i8) {
+ num_traits::float::Float::integer_decode(self.to_f32())
+ }
+}
+
+impl FloatConst for bf16 {
+ #[inline]
+ fn E() -> Self {
+ Self::E
+ }
+
+ #[inline]
+ fn FRAC_1_PI() -> Self {
+ Self::FRAC_1_PI
+ }
+
+ #[inline]
+ fn FRAC_1_SQRT_2() -> Self {
+ Self::FRAC_1_SQRT_2
+ }
+
+ #[inline]
+ fn FRAC_2_PI() -> Self {
+ Self::FRAC_2_PI
+ }
+
+ #[inline]
+ fn FRAC_2_SQRT_PI() -> Self {
+ Self::FRAC_2_SQRT_PI
+ }
+
+ #[inline]
+ fn FRAC_PI_2() -> Self {
+ Self::FRAC_PI_2
+ }
+
+ #[inline]
+ fn FRAC_PI_3() -> Self {
+ Self::FRAC_PI_3
+ }
+
+ #[inline]
+ fn FRAC_PI_4() -> Self {
+ Self::FRAC_PI_4
+ }
+
+ #[inline]
+ fn FRAC_PI_6() -> Self {
+ Self::FRAC_PI_6
+ }
+
+ #[inline]
+ fn FRAC_PI_8() -> Self {
+ Self::FRAC_PI_8
+ }
+
+ #[inline]
+ fn LN_10() -> Self {
+ Self::LN_10
+ }
+
+ #[inline]
+ fn LN_2() -> Self {
+ Self::LN_2
+ }
+
+ #[inline]
+ fn LOG10_E() -> Self {
+ Self::LOG10_E
+ }
+
+ #[inline]
+ fn LOG2_E() -> Self {
+ Self::LOG2_E
+ }
+
+ #[inline]
+ fn PI() -> Self {
+ Self::PI
+ }
+
+ #[inline]
+ fn SQRT_2() -> Self {
+ Self::SQRT_2
+ }
+
+ #[inline]
+ fn LOG10_2() -> Self
+ where
+ Self: Sized + Div<Self, Output = Self>,
+ {
+ Self::LOG10_2
+ }
+
+ #[inline]
+ fn LOG2_10() -> Self
+ where
+ Self: Sized + Div<Self, Output = Self>,
+ {
+ Self::LOG2_10
+ }
+}
+
+impl Bounded for bf16 {
+ #[inline]
+ fn min_value() -> Self {
+ bf16::MIN
+ }
+
+ #[inline]
+ fn max_value() -> Self {
+ bf16::MAX
+ }
+}
+
+impl AsPrimitive<bf16> for bf16 {
+ #[inline]
+ fn as_(self) -> bf16 {
+ self
+ }
+}
+
+macro_rules! impl_as_primitive_to_bf16 {
+ ($ty:ty, $meth:ident) => {
+ impl AsPrimitive<$ty> for bf16 {
+ #[inline]
+ fn as_(self) -> $ty {
+ self.$meth().as_()
+ }
+ }
+ };
+}
+
+impl_as_primitive_to_bf16!(i64, to_f32);
+impl_as_primitive_to_bf16!(u64, to_f32);
+impl_as_primitive_to_bf16!(i8, to_f32);
+impl_as_primitive_to_bf16!(u8, to_f32);
+impl_as_primitive_to_bf16!(i16, to_f32);
+impl_as_primitive_to_bf16!(u16, to_f32);
+impl_as_primitive_to_bf16!(i32, to_f32);
+impl_as_primitive_to_bf16!(u32, to_f32);
+impl_as_primitive_to_bf16!(isize, to_f32);
+impl_as_primitive_to_bf16!(usize, to_f32);
+impl_as_primitive_to_bf16!(f32, to_f32);
+impl_as_primitive_to_bf16!(f64, to_f64);
+
+macro_rules! impl_as_primitive_bf16_from {
+ ($ty:ty, $meth:ident) => {
+ impl AsPrimitive<bf16> for $ty {
+ #[inline]
+ fn as_(self) -> bf16 {
+ bf16::$meth(self.as_())
+ }
+ }
+ };
+}
+
+impl_as_primitive_bf16_from!(i64, from_f32);
+impl_as_primitive_bf16_from!(u64, from_f32);
+impl_as_primitive_bf16_from!(i8, from_f32);
+impl_as_primitive_bf16_from!(u8, from_f32);
+impl_as_primitive_bf16_from!(i16, from_f32);
+impl_as_primitive_bf16_from!(u16, from_f32);
+impl_as_primitive_bf16_from!(i32, from_f32);
+impl_as_primitive_bf16_from!(u32, from_f32);
+impl_as_primitive_bf16_from!(isize, from_f32);
+impl_as_primitive_bf16_from!(usize, from_f32);
+impl_as_primitive_bf16_from!(f32, from_f32);
+impl_as_primitive_bf16_from!(f64, from_f64);
--- /dev/null
+//! Contains utility functions and traits to convert between slices of [`u16`] bits and [`f16`] or
+//! [`bf16`] numbers.
+//!
+//! The utility [`HalfBitsSliceExt`] sealed extension trait is implemented for `[u16]` slices,
+//! while the utility [`HalfFloatSliceExt`] sealed extension trait is implemented for both `[f16]`
+//! and `[bf16]` slices. These traits provide efficient conversions and reinterpret casting of
+//! larger buffers of floating point values, and are automatically included in the
+//! [`prelude`][crate::prelude] module.
+
+use crate::{bf16, binary16::convert, f16};
+#[cfg(feature = "alloc")]
+use alloc::vec::Vec;
+use core::slice;
+
+/// Extensions to `[f16]` and `[bf16]` slices to support conversion and reinterpret operations.
+///
+/// This trait is sealed and cannot be implemented outside of this crate.
+pub trait HalfFloatSliceExt: private::SealedHalfFloatSlice {
+ /// Reinterprets a slice of [`f16`] or [`bf16`] numbers as a slice of [`u16`] bits.
+ ///
+ /// This is a zero-copy operation. The reinterpreted slice has the same lifetime and memory
+ /// location as `self`.
+ ///
+ /// # Examples
+ ///
+ /// ```rust
+ /// # use half::prelude::*;
+ /// let float_buffer = [f16::from_f32(1.), f16::from_f32(2.), f16::from_f32(3.)];
+ /// let int_buffer = float_buffer.reinterpret_cast();
+ ///
+ /// assert_eq!(int_buffer, [float_buffer[0].to_bits(), float_buffer[1].to_bits(), float_buffer[2].to_bits()]);
+ /// ```
+ #[must_use]
+ fn reinterpret_cast(&self) -> &[u16];
+
+ /// Reinterprets a mutable slice of [`f16`] or [`bf16`] numbers as a mutable slice of [`u16`].
+ /// bits
+ ///
+ /// This is a zero-copy operation. The transmuted slice has the same lifetime as the original,
+ /// which prevents mutating `self` as long as the returned `&mut [u16]` is borrowed.
+ ///
+ /// # Examples
+ ///
+ /// ```rust
+ /// # use half::prelude::*;
+ /// let mut float_buffer = [f16::from_f32(1.), f16::from_f32(2.), f16::from_f32(3.)];
+ ///
+ /// {
+ /// let int_buffer = float_buffer.reinterpret_cast_mut();
+ ///
+ /// assert_eq!(int_buffer, [f16::from_f32(1.).to_bits(), f16::from_f32(2.).to_bits(), f16::from_f32(3.).to_bits()]);
+ ///
+ /// // Mutating the u16 slice will mutating the original
+ /// int_buffer[0] = 0;
+ /// }
+ ///
+ /// // Note that we need to drop int_buffer before using float_buffer again or we will get a borrow error.
+ /// assert_eq!(float_buffer, [f16::from_f32(0.), f16::from_f32(2.), f16::from_f32(3.)]);
+ /// ```
+ #[must_use]
+ fn reinterpret_cast_mut(&mut self) -> &mut [u16];
+
+ /// Converts all of the elements of a `[f32]` slice into [`f16`] or [`bf16`] values in `self`.
+ ///
+ /// The length of `src` must be the same as `self`.
+ ///
+ /// The conversion operation is vectorized over the slice, meaning the conversion may be more
+ /// efficient than converting individual elements on some hardware that supports SIMD
+ /// conversions. See [crate documentation](crate) for more information on hardware conversion
+ /// support.
+ ///
+ /// # Panics
+ ///
+ /// This function will panic if the two slices have different lengths.
+ ///
+ /// # Examples
+ /// ```rust
+ /// # use half::prelude::*;
+ /// // Initialize an empty buffer
+ /// let mut buffer = [0u16; 4];
+ /// let buffer = buffer.reinterpret_cast_mut::<f16>();
+ ///
+ /// let float_values = [1., 2., 3., 4.];
+ ///
+ /// // Now convert
+ /// buffer.convert_from_f32_slice(&float_values);
+ ///
+ /// assert_eq!(buffer, [f16::from_f32(1.), f16::from_f32(2.), f16::from_f32(3.), f16::from_f32(4.)]);
+ /// ```
+ fn convert_from_f32_slice(&mut self, src: &[f32]);
+
+ /// Converts all of the elements of a `[f64]` slice into [`f16`] or [`bf16`] values in `self`.
+ ///
+ /// The length of `src` must be the same as `self`.
+ ///
+ /// The conversion operation is vectorized over the slice, meaning the conversion may be more
+ /// efficient than converting individual elements on some hardware that supports SIMD
+ /// conversions. See [crate documentation](crate) for more information on hardware conversion
+ /// support.
+ ///
+ /// # Panics
+ ///
+ /// This function will panic if the two slices have different lengths.
+ ///
+ /// # Examples
+ /// ```rust
+ /// # use half::prelude::*;
+ /// // Initialize an empty buffer
+ /// let mut buffer = [0u16; 4];
+ /// let buffer = buffer.reinterpret_cast_mut::<f16>();
+ ///
+ /// let float_values = [1., 2., 3., 4.];
+ ///
+ /// // Now convert
+ /// buffer.convert_from_f64_slice(&float_values);
+ ///
+ /// assert_eq!(buffer, [f16::from_f64(1.), f16::from_f64(2.), f16::from_f64(3.), f16::from_f64(4.)]);
+ /// ```
+ fn convert_from_f64_slice(&mut self, src: &[f64]);
+
+ /// Converts all of the [`f16`] or [`bf16`] elements of `self` into [`f32`] values in `dst`.
+ ///
+ /// The length of `src` must be the same as `self`.
+ ///
+ /// The conversion operation is vectorized over the slice, meaning the conversion may be more
+ /// efficient than converting individual elements on some hardware that supports SIMD
+ /// conversions. See [crate documentation](crate) for more information on hardware conversion
+ /// support.
+ ///
+ /// # Panics
+ ///
+ /// This function will panic if the two slices have different lengths.
+ ///
+ /// # Examples
+ /// ```rust
+ /// # use half::prelude::*;
+ /// // Initialize an empty buffer
+ /// let mut buffer = [0f32; 4];
+ ///
+ /// let half_values = [f16::from_f32(1.), f16::from_f32(2.), f16::from_f32(3.), f16::from_f32(4.)];
+ ///
+ /// // Now convert
+ /// half_values.convert_to_f32_slice(&mut buffer);
+ ///
+ /// assert_eq!(buffer, [1., 2., 3., 4.]);
+ /// ```
+ fn convert_to_f32_slice(&self, dst: &mut [f32]);
+
+ /// Converts all of the [`f16`] or [`bf16`] elements of `self` into [`f64`] values in `dst`.
+ ///
+ /// The length of `src` must be the same as `self`.
+ ///
+ /// The conversion operation is vectorized over the slice, meaning the conversion may be more
+ /// efficient than converting individual elements on some hardware that supports SIMD
+ /// conversions. See [crate documentation](crate) for more information on hardware conversion
+ /// support.
+ ///
+ /// # Panics
+ ///
+ /// This function will panic if the two slices have different lengths.
+ ///
+ /// # Examples
+ /// ```rust
+ /// # use half::prelude::*;
+ /// // Initialize an empty buffer
+ /// let mut buffer = [0f64; 4];
+ ///
+ /// let half_values = [f16::from_f64(1.), f16::from_f64(2.), f16::from_f64(3.), f16::from_f64(4.)];
+ ///
+ /// // Now convert
+ /// half_values.convert_to_f64_slice(&mut buffer);
+ ///
+ /// assert_eq!(buffer, [1., 2., 3., 4.]);
+ /// ```
+ fn convert_to_f64_slice(&self, dst: &mut [f64]);
+
+ // Because trait is sealed, we can get away with different interfaces between features.
+
+ /// Converts all of the [`f16`] or [`bf16`] elements of `self` into [`f32`] values in a new
+ /// vector
+ ///
+ /// The conversion operation is vectorized over the slice, meaning the conversion may be more
+ /// efficient than converting individual elements on some hardware that supports SIMD
+ /// conversions. See [crate documentation](crate) for more information on hardware conversion
+ /// support.
+ ///
+ /// This method is only available with the `std` or `alloc` feature.
+ ///
+ /// # Examples
+ /// ```rust
+ /// # use half::prelude::*;
+ /// let half_values = [f16::from_f32(1.), f16::from_f32(2.), f16::from_f32(3.), f16::from_f32(4.)];
+ /// let vec = half_values.to_f32_vec();
+ ///
+ /// assert_eq!(vec, vec![1., 2., 3., 4.]);
+ /// ```
+ #[cfg(any(feature = "alloc", feature = "std"))]
+ #[cfg_attr(docsrs, doc(cfg(feature = "alloc")))]
+ #[must_use]
+ fn to_f32_vec(&self) -> Vec<f32>;
+
+ /// Converts all of the [`f16`] or [`bf16`] elements of `self` into [`f64`] values in a new
+ /// vector.
+ ///
+ /// The conversion operation is vectorized over the slice, meaning the conversion may be more
+ /// efficient than converting individual elements on some hardware that supports SIMD
+ /// conversions. See [crate documentation](crate) for more information on hardware conversion
+ /// support.
+ ///
+ /// This method is only available with the `std` or `alloc` feature.
+ ///
+ /// # Examples
+ /// ```rust
+ /// # use half::prelude::*;
+ /// let half_values = [f16::from_f64(1.), f16::from_f64(2.), f16::from_f64(3.), f16::from_f64(4.)];
+ /// let vec = half_values.to_f64_vec();
+ ///
+ /// assert_eq!(vec, vec![1., 2., 3., 4.]);
+ /// ```
+ #[cfg(feature = "alloc")]
+ #[cfg_attr(docsrs, doc(cfg(feature = "alloc")))]
+ #[must_use]
+ fn to_f64_vec(&self) -> Vec<f64>;
+}
+
+/// Extensions to `[u16]` slices to support reinterpret operations.
+///
+/// This trait is sealed and cannot be implemented outside of this crate.
+pub trait HalfBitsSliceExt: private::SealedHalfBitsSlice {
+ /// Reinterprets a slice of [`u16`] bits as a slice of [`f16`] or [`bf16`] numbers.
+ ///
+ /// `H` is the type to cast to, and must be either the [`f16`] or [`bf16`] type.
+ ///
+ /// This is a zero-copy operation. The reinterpreted slice has the same lifetime and memory
+ /// location as `self`.
+ ///
+ /// # Examples
+ ///
+ /// ```rust
+ /// # use half::prelude::*;
+ /// let int_buffer = [f16::from_f32(1.).to_bits(), f16::from_f32(2.).to_bits(), f16::from_f32(3.).to_bits()];
+ /// let float_buffer: &[f16] = int_buffer.reinterpret_cast();
+ ///
+ /// assert_eq!(float_buffer, [f16::from_f32(1.), f16::from_f32(2.), f16::from_f32(3.)]);
+ ///
+ /// // You may have to specify the cast type directly if the compiler can't infer the type.
+ /// // The following is also valid in Rust.
+ /// let typed_buffer = int_buffer.reinterpret_cast::<f16>();
+ /// ```
+ #[must_use]
+ fn reinterpret_cast<H>(&self) -> &[H]
+ where
+ H: crate::private::SealedHalf;
+
+ /// Reinterprets a mutable slice of [`u16`] bits as a mutable slice of [`f16`] or [`bf16`]
+ /// numbers.
+ ///
+ /// `H` is the type to cast to, and must be either the [`f16`] or [`bf16`] type.
+ ///
+ /// This is a zero-copy operation. The transmuted slice has the same lifetime as the original,
+ /// which prevents mutating `self` as long as the returned `&mut [f16]` is borrowed.
+ ///
+ /// # Examples
+ ///
+ /// ```rust
+ /// # use half::prelude::*;
+ /// let mut int_buffer = [f16::from_f32(1.).to_bits(), f16::from_f32(2.).to_bits(), f16::from_f32(3.).to_bits()];
+ ///
+ /// {
+ /// let float_buffer: &mut [f16] = int_buffer.reinterpret_cast_mut();
+ ///
+ /// assert_eq!(float_buffer, [f16::from_f32(1.), f16::from_f32(2.), f16::from_f32(3.)]);
+ ///
+ /// // Mutating the f16 slice will mutating the original
+ /// float_buffer[0] = f16::from_f32(0.);
+ /// }
+ ///
+ /// // Note that we need to drop float_buffer before using int_buffer again or we will get a borrow error.
+ /// assert_eq!(int_buffer, [f16::from_f32(0.).to_bits(), f16::from_f32(2.).to_bits(), f16::from_f32(3.).to_bits()]);
+ ///
+ /// // You may have to specify the cast type directly if the compiler can't infer the type.
+ /// // The following is also valid in Rust.
+ /// let typed_buffer = int_buffer.reinterpret_cast_mut::<f16>();
+ /// ```
+ #[must_use]
+ fn reinterpret_cast_mut<H>(&mut self) -> &mut [H]
+ where
+ H: crate::private::SealedHalf;
+}
+
+mod private {
+ use crate::{bf16, f16};
+
+ pub trait SealedHalfFloatSlice {}
+ impl SealedHalfFloatSlice for [f16] {}
+ impl SealedHalfFloatSlice for [bf16] {}
+
+ pub trait SealedHalfBitsSlice {}
+ impl SealedHalfBitsSlice for [u16] {}
+}
+
+impl HalfFloatSliceExt for [f16] {
+ #[inline]
+ fn reinterpret_cast(&self) -> &[u16] {
+ let pointer = self.as_ptr() as *const u16;
+ let length = self.len();
+ // SAFETY: We are reconstructing full length of original slice, using its same lifetime,
+ // and the size of elements are identical
+ unsafe { slice::from_raw_parts(pointer, length) }
+ }
+
+ #[inline]
+ fn reinterpret_cast_mut(&mut self) -> &mut [u16] {
+ let pointer = self.as_mut_ptr().cast::<u16>();
+ let length = self.len();
+ // SAFETY: We are reconstructing full length of original slice, using its same lifetime,
+ // and the size of elements are identical
+ unsafe { slice::from_raw_parts_mut(pointer, length) }
+ }
+
+ fn convert_from_f32_slice(&mut self, src: &[f32]) {
+ assert_eq!(
+ self.len(),
+ src.len(),
+ "destination and source slices have different lengths"
+ );
+
+ convert::f32_to_f16_slice(src, self.reinterpret_cast_mut())
+ }
+
+ fn convert_from_f64_slice(&mut self, src: &[f64]) {
+ assert_eq!(
+ self.len(),
+ src.len(),
+ "destination and source slices have different lengths"
+ );
+
+ convert::f64_to_f16_slice(src, self.reinterpret_cast_mut())
+ }
+
+ fn convert_to_f32_slice(&self, dst: &mut [f32]) {
+ assert_eq!(
+ self.len(),
+ dst.len(),
+ "destination and source slices have different lengths"
+ );
+
+ convert::f16_to_f32_slice(self.reinterpret_cast(), dst)
+ }
+
+ fn convert_to_f64_slice(&self, dst: &mut [f64]) {
+ assert_eq!(
+ self.len(),
+ dst.len(),
+ "destination and source slices have different lengths"
+ );
+
+ convert::f16_to_f64_slice(self.reinterpret_cast(), dst)
+ }
+
+ #[cfg(any(feature = "alloc", feature = "std"))]
+ #[inline]
+ #[allow(clippy::uninit_vec)]
+ fn to_f32_vec(&self) -> Vec<f32> {
+ let mut vec = Vec::with_capacity(self.len());
+ // SAFETY: convert will initialize every value in the vector without reading them,
+ // so this is safe to do instead of double initialize from resize, and we're setting it to
+ // same value as capacity.
+ unsafe { vec.set_len(self.len()) };
+ self.convert_to_f32_slice(&mut vec);
+ vec
+ }
+
+ #[cfg(any(feature = "alloc", feature = "std"))]
+ #[inline]
+ #[allow(clippy::uninit_vec)]
+ fn to_f64_vec(&self) -> Vec<f64> {
+ let mut vec = Vec::with_capacity(self.len());
+ // SAFETY: convert will initialize every value in the vector without reading them,
+ // so this is safe to do instead of double initialize from resize, and we're setting it to
+ // same value as capacity.
+ unsafe { vec.set_len(self.len()) };
+ self.convert_to_f64_slice(&mut vec);
+ vec
+ }
+}
+
+impl HalfFloatSliceExt for [bf16] {
+ #[inline]
+ fn reinterpret_cast(&self) -> &[u16] {
+ let pointer = self.as_ptr() as *const u16;
+ let length = self.len();
+ // SAFETY: We are reconstructing full length of original slice, using its same lifetime,
+ // and the size of elements are identical
+ unsafe { slice::from_raw_parts(pointer, length) }
+ }
+
+ #[inline]
+ fn reinterpret_cast_mut(&mut self) -> &mut [u16] {
+ let pointer = self.as_mut_ptr().cast::<u16>();
+ let length = self.len();
+ // SAFETY: We are reconstructing full length of original slice, using its same lifetime,
+ // and the size of elements are identical
+ unsafe { slice::from_raw_parts_mut(pointer, length) }
+ }
+
+ fn convert_from_f32_slice(&mut self, src: &[f32]) {
+ assert_eq!(
+ self.len(),
+ src.len(),
+ "destination and source slices have different lengths"
+ );
+
+ // Just use regular loop here until there's any bf16 SIMD support.
+ for (i, f) in src.iter().enumerate() {
+ self[i] = bf16::from_f32(*f);
+ }
+ }
+
+ fn convert_from_f64_slice(&mut self, src: &[f64]) {
+ assert_eq!(
+ self.len(),
+ src.len(),
+ "destination and source slices have different lengths"
+ );
+
+ // Just use regular loop here until there's any bf16 SIMD support.
+ for (i, f) in src.iter().enumerate() {
+ self[i] = bf16::from_f64(*f);
+ }
+ }
+
+ fn convert_to_f32_slice(&self, dst: &mut [f32]) {
+ assert_eq!(
+ self.len(),
+ dst.len(),
+ "destination and source slices have different lengths"
+ );
+
+ // Just use regular loop here until there's any bf16 SIMD support.
+ for (i, f) in self.iter().enumerate() {
+ dst[i] = f.to_f32();
+ }
+ }
+
+ fn convert_to_f64_slice(&self, dst: &mut [f64]) {
+ assert_eq!(
+ self.len(),
+ dst.len(),
+ "destination and source slices have different lengths"
+ );
+
+ // Just use regular loop here until there's any bf16 SIMD support.
+ for (i, f) in self.iter().enumerate() {
+ dst[i] = f.to_f64();
+ }
+ }
+
+ #[cfg(any(feature = "alloc", feature = "std"))]
+ #[inline]
+ #[allow(clippy::uninit_vec)]
+ fn to_f32_vec(&self) -> Vec<f32> {
+ let mut vec = Vec::with_capacity(self.len());
+ // SAFETY: convert will initialize every value in the vector without reading them,
+ // so this is safe to do instead of double initialize from resize, and we're setting it to
+ // same value as capacity.
+ unsafe { vec.set_len(self.len()) };
+ self.convert_to_f32_slice(&mut vec);
+ vec
+ }
+
+ #[cfg(any(feature = "alloc", feature = "std"))]
+ #[inline]
+ #[allow(clippy::uninit_vec)]
+ fn to_f64_vec(&self) -> Vec<f64> {
+ let mut vec = Vec::with_capacity(self.len());
+ // SAFETY: convert will initialize every value in the vector without reading them,
+ // so this is safe to do instead of double initialize from resize, and we're setting it to
+ // same value as capacity.
+ unsafe { vec.set_len(self.len()) };
+ self.convert_to_f64_slice(&mut vec);
+ vec
+ }
+}
+
+impl HalfBitsSliceExt for [u16] {
+ // Since we sealed all the traits involved, these are safe.
+ #[inline]
+ fn reinterpret_cast<H>(&self) -> &[H]
+ where
+ H: crate::private::SealedHalf,
+ {
+ let pointer = self.as_ptr() as *const H;
+ let length = self.len();
+ // SAFETY: We are reconstructing full length of original slice, using its same lifetime,
+ // and the size of elements are identical
+ unsafe { slice::from_raw_parts(pointer, length) }
+ }
+
+ #[inline]
+ fn reinterpret_cast_mut<H>(&mut self) -> &mut [H]
+ where
+ H: crate::private::SealedHalf,
+ {
+ let pointer = self.as_mut_ptr() as *mut H;
+ let length = self.len();
+ // SAFETY: We are reconstructing full length of original slice, using its same lifetime,
+ // and the size of elements are identical
+ unsafe { slice::from_raw_parts_mut(pointer, length) }
+ }
+}
+
+#[allow(clippy::float_cmp)]
+#[cfg(test)]
+mod test {
+ use super::{HalfBitsSliceExt, HalfFloatSliceExt};
+ use crate::{bf16, f16};
+
+ #[test]
+ fn test_slice_conversions_f16() {
+ let bits = &[
+ f16::E.to_bits(),
+ f16::PI.to_bits(),
+ f16::EPSILON.to_bits(),
+ f16::FRAC_1_SQRT_2.to_bits(),
+ ];
+ let numbers = &[f16::E, f16::PI, f16::EPSILON, f16::FRAC_1_SQRT_2];
+
+ // Convert from bits to numbers
+ let from_bits = bits.reinterpret_cast::<f16>();
+ assert_eq!(from_bits, numbers);
+
+ // Convert from numbers back to bits
+ let to_bits = from_bits.reinterpret_cast();
+ assert_eq!(to_bits, bits);
+ }
+
+ #[test]
+ fn test_mutablility_f16() {
+ let mut bits_array = [f16::PI.to_bits()];
+ let bits = &mut bits_array[..];
+
+ {
+ // would not compile without these braces
+ let numbers = bits.reinterpret_cast_mut();
+ numbers[0] = f16::E;
+ }
+
+ assert_eq!(bits, &[f16::E.to_bits()]);
+
+ bits[0] = f16::LN_2.to_bits();
+ assert_eq!(bits, &[f16::LN_2.to_bits()]);
+ }
+
+ #[test]
+ fn test_slice_conversions_bf16() {
+ let bits = &[
+ bf16::E.to_bits(),
+ bf16::PI.to_bits(),
+ bf16::EPSILON.to_bits(),
+ bf16::FRAC_1_SQRT_2.to_bits(),
+ ];
+ let numbers = &[bf16::E, bf16::PI, bf16::EPSILON, bf16::FRAC_1_SQRT_2];
+
+ // Convert from bits to numbers
+ let from_bits = bits.reinterpret_cast::<bf16>();
+ assert_eq!(from_bits, numbers);
+
+ // Convert from numbers back to bits
+ let to_bits = from_bits.reinterpret_cast();
+ assert_eq!(to_bits, bits);
+ }
+
+ #[test]
+ fn test_mutablility_bf16() {
+ let mut bits_array = [bf16::PI.to_bits()];
+ let bits = &mut bits_array[..];
+
+ {
+ // would not compile without these braces
+ let numbers = bits.reinterpret_cast_mut();
+ numbers[0] = bf16::E;
+ }
+
+ assert_eq!(bits, &[bf16::E.to_bits()]);
+
+ bits[0] = bf16::LN_2.to_bits();
+ assert_eq!(bits, &[bf16::LN_2.to_bits()]);
+ }
+
+ #[test]
+ fn slice_convert_f16_f32() {
+ // Exact chunks
+ let vf32 = [1., 2., 3., 4., 5., 6., 7., 8.];
+ let vf16 = [
+ f16::from_f32(1.),
+ f16::from_f32(2.),
+ f16::from_f32(3.),
+ f16::from_f32(4.),
+ f16::from_f32(5.),
+ f16::from_f32(6.),
+ f16::from_f32(7.),
+ f16::from_f32(8.),
+ ];
+ let mut buf32 = vf32;
+ let mut buf16 = vf16;
+
+ vf16.convert_to_f32_slice(&mut buf32);
+ assert_eq!(&vf32, &buf32);
+
+ buf16.convert_from_f32_slice(&vf32);
+ assert_eq!(&vf16, &buf16);
+
+ // Partial with chunks
+ let vf32 = [1., 2., 3., 4., 5., 6., 7., 8., 9.];
+ let vf16 = [
+ f16::from_f32(1.),
+ f16::from_f32(2.),
+ f16::from_f32(3.),
+ f16::from_f32(4.),
+ f16::from_f32(5.),
+ f16::from_f32(6.),
+ f16::from_f32(7.),
+ f16::from_f32(8.),
+ f16::from_f32(9.),
+ ];
+ let mut buf32 = vf32;
+ let mut buf16 = vf16;
+
+ vf16.convert_to_f32_slice(&mut buf32);
+ assert_eq!(&vf32, &buf32);
+
+ buf16.convert_from_f32_slice(&vf32);
+ assert_eq!(&vf16, &buf16);
+
+ // Partial with chunks
+ let vf32 = [1., 2.];
+ let vf16 = [f16::from_f32(1.), f16::from_f32(2.)];
+ let mut buf32 = vf32;
+ let mut buf16 = vf16;
+
+ vf16.convert_to_f32_slice(&mut buf32);
+ assert_eq!(&vf32, &buf32);
+
+ buf16.convert_from_f32_slice(&vf32);
+ assert_eq!(&vf16, &buf16);
+ }
+
+ #[test]
+ fn slice_convert_bf16_f32() {
+ // Exact chunks
+ let vf32 = [1., 2., 3., 4., 5., 6., 7., 8.];
+ let vf16 = [
+ bf16::from_f32(1.),
+ bf16::from_f32(2.),
+ bf16::from_f32(3.),
+ bf16::from_f32(4.),
+ bf16::from_f32(5.),
+ bf16::from_f32(6.),
+ bf16::from_f32(7.),
+ bf16::from_f32(8.),
+ ];
+ let mut buf32 = vf32;
+ let mut buf16 = vf16;
+
+ vf16.convert_to_f32_slice(&mut buf32);
+ assert_eq!(&vf32, &buf32);
+
+ buf16.convert_from_f32_slice(&vf32);
+ assert_eq!(&vf16, &buf16);
+
+ // Partial with chunks
+ let vf32 = [1., 2., 3., 4., 5., 6., 7., 8., 9.];
+ let vf16 = [
+ bf16::from_f32(1.),
+ bf16::from_f32(2.),
+ bf16::from_f32(3.),
+ bf16::from_f32(4.),
+ bf16::from_f32(5.),
+ bf16::from_f32(6.),
+ bf16::from_f32(7.),
+ bf16::from_f32(8.),
+ bf16::from_f32(9.),
+ ];
+ let mut buf32 = vf32;
+ let mut buf16 = vf16;
+
+ vf16.convert_to_f32_slice(&mut buf32);
+ assert_eq!(&vf32, &buf32);
+
+ buf16.convert_from_f32_slice(&vf32);
+ assert_eq!(&vf16, &buf16);
+
+ // Partial with chunks
+ let vf32 = [1., 2.];
+ let vf16 = [bf16::from_f32(1.), bf16::from_f32(2.)];
+ let mut buf32 = vf32;
+ let mut buf16 = vf16;
+
+ vf16.convert_to_f32_slice(&mut buf32);
+ assert_eq!(&vf32, &buf32);
+
+ buf16.convert_from_f32_slice(&vf32);
+ assert_eq!(&vf16, &buf16);
+ }
+
+ #[test]
+ fn slice_convert_f16_f64() {
+ // Exact chunks
+ let vf64 = [1., 2., 3., 4., 5., 6., 7., 8.];
+ let vf16 = [
+ f16::from_f64(1.),
+ f16::from_f64(2.),
+ f16::from_f64(3.),
+ f16::from_f64(4.),
+ f16::from_f64(5.),
+ f16::from_f64(6.),
+ f16::from_f64(7.),
+ f16::from_f64(8.),
+ ];
+ let mut buf64 = vf64;
+ let mut buf16 = vf16;
+
+ vf16.convert_to_f64_slice(&mut buf64);
+ assert_eq!(&vf64, &buf64);
+
+ buf16.convert_from_f64_slice(&vf64);
+ assert_eq!(&vf16, &buf16);
+
+ // Partial with chunks
+ let vf64 = [1., 2., 3., 4., 5., 6., 7., 8., 9.];
+ let vf16 = [
+ f16::from_f64(1.),
+ f16::from_f64(2.),
+ f16::from_f64(3.),
+ f16::from_f64(4.),
+ f16::from_f64(5.),
+ f16::from_f64(6.),
+ f16::from_f64(7.),
+ f16::from_f64(8.),
+ f16::from_f64(9.),
+ ];
+ let mut buf64 = vf64;
+ let mut buf16 = vf16;
+
+ vf16.convert_to_f64_slice(&mut buf64);
+ assert_eq!(&vf64, &buf64);
+
+ buf16.convert_from_f64_slice(&vf64);
+ assert_eq!(&vf16, &buf16);
+
+ // Partial with chunks
+ let vf64 = [1., 2.];
+ let vf16 = [f16::from_f64(1.), f16::from_f64(2.)];
+ let mut buf64 = vf64;
+ let mut buf16 = vf16;
+
+ vf16.convert_to_f64_slice(&mut buf64);
+ assert_eq!(&vf64, &buf64);
+
+ buf16.convert_from_f64_slice(&vf64);
+ assert_eq!(&vf16, &buf16);
+ }
+
+ #[test]
+ fn slice_convert_bf16_f64() {
+ // Exact chunks
+ let vf64 = [1., 2., 3., 4., 5., 6., 7., 8.];
+ let vf16 = [
+ bf16::from_f64(1.),
+ bf16::from_f64(2.),
+ bf16::from_f64(3.),
+ bf16::from_f64(4.),
+ bf16::from_f64(5.),
+ bf16::from_f64(6.),
+ bf16::from_f64(7.),
+ bf16::from_f64(8.),
+ ];
+ let mut buf64 = vf64;
+ let mut buf16 = vf16;
+
+ vf16.convert_to_f64_slice(&mut buf64);
+ assert_eq!(&vf64, &buf64);
+
+ buf16.convert_from_f64_slice(&vf64);
+ assert_eq!(&vf16, &buf16);
+
+ // Partial with chunks
+ let vf64 = [1., 2., 3., 4., 5., 6., 7., 8., 9.];
+ let vf16 = [
+ bf16::from_f64(1.),
+ bf16::from_f64(2.),
+ bf16::from_f64(3.),
+ bf16::from_f64(4.),
+ bf16::from_f64(5.),
+ bf16::from_f64(6.),
+ bf16::from_f64(7.),
+ bf16::from_f64(8.),
+ bf16::from_f64(9.),
+ ];
+ let mut buf64 = vf64;
+ let mut buf16 = vf16;
+
+ vf16.convert_to_f64_slice(&mut buf64);
+ assert_eq!(&vf64, &buf64);
+
+ buf16.convert_from_f64_slice(&vf64);
+ assert_eq!(&vf16, &buf16);
+
+ // Partial with chunks
+ let vf64 = [1., 2.];
+ let vf16 = [bf16::from_f64(1.), bf16::from_f64(2.)];
+ let mut buf64 = vf64;
+ let mut buf16 = vf16;
+
+ vf16.convert_to_f64_slice(&mut buf64);
+ assert_eq!(&vf64, &buf64);
+
+ buf16.convert_from_f64_slice(&vf64);
+ assert_eq!(&vf16, &buf16);
+ }
+
+ #[test]
+ #[should_panic]
+ fn convert_from_f32_slice_len_mismatch_panics() {
+ let mut slice1 = [f16::ZERO; 3];
+ let slice2 = [0f32; 4];
+ slice1.convert_from_f32_slice(&slice2);
+ }
+
+ #[test]
+ #[should_panic]
+ fn convert_from_f64_slice_len_mismatch_panics() {
+ let mut slice1 = [f16::ZERO; 3];
+ let slice2 = [0f64; 4];
+ slice1.convert_from_f64_slice(&slice2);
+ }
+
+ #[test]
+ #[should_panic]
+ fn convert_to_f32_slice_len_mismatch_panics() {
+ let slice1 = [f16::ZERO; 3];
+ let mut slice2 = [0f32; 4];
+ slice1.convert_to_f32_slice(&mut slice2);
+ }
+
+ #[test]
+ #[should_panic]
+ fn convert_to_f64_slice_len_mismatch_panics() {
+ let slice1 = [f16::ZERO; 3];
+ let mut slice2 = [0f64; 4];
+ slice1.convert_to_f64_slice(&mut slice2);
+ }
+}
--- /dev/null
+//! Contains utility functions and traits to convert between vectors of [`u16`] bits and [`f16`] or
+//! [`bf16`] vectors.
+//!
+//! The utility [`HalfBitsVecExt`] sealed extension trait is implemented for [`Vec<u16>`] vectors,
+//! while the utility [`HalfFloatVecExt`] sealed extension trait is implemented for both
+//! [`Vec<f16>`] and [`Vec<bf16>`] vectors. These traits provide efficient conversions and
+//! reinterpret casting of larger buffers of floating point values, and are automatically included
+//! in the [`prelude`][crate::prelude] module.
+//!
+//! This module is only available with the `std` or `alloc` feature.
+
+use super::{bf16, f16, slice::HalfFloatSliceExt};
+#[cfg(feature = "alloc")]
+use alloc::vec::Vec;
+use core::mem;
+
+/// Extensions to [`Vec<f16>`] and [`Vec<bf16>`] to support reinterpret operations.
+///
+/// This trait is sealed and cannot be implemented outside of this crate.
+pub trait HalfFloatVecExt: private::SealedHalfFloatVec {
+ /// Reinterprets a vector of [`f16`]or [`bf16`] numbers as a vector of [`u16`] bits.
+ ///
+ /// This is a zero-copy operation. The reinterpreted vector has the same memory location as
+ /// `self`.
+ ///
+ /// # Examples
+ ///
+ /// ```rust
+ /// # use half::prelude::*;
+ /// let float_buffer = vec![f16::from_f32(1.), f16::from_f32(2.), f16::from_f32(3.)];
+ /// let int_buffer = float_buffer.reinterpret_into();
+ ///
+ /// assert_eq!(int_buffer, [f16::from_f32(1.).to_bits(), f16::from_f32(2.).to_bits(), f16::from_f32(3.).to_bits()]);
+ /// ```
+ #[must_use]
+ fn reinterpret_into(self) -> Vec<u16>;
+
+ /// Converts all of the elements of a `[f32]` slice into a new [`f16`] or [`bf16`] vector.
+ ///
+ /// The conversion operation is vectorized over the slice, meaning the conversion may be more
+ /// efficient than converting individual elements on some hardware that supports SIMD
+ /// conversions. See [crate documentation][crate] for more information on hardware conversion
+ /// support.
+ ///
+ /// # Examples
+ /// ```rust
+ /// # use half::prelude::*;
+ /// let float_values = [1., 2., 3., 4.];
+ /// let vec: Vec<f16> = Vec::from_f32_slice(&float_values);
+ ///
+ /// assert_eq!(vec, vec![f16::from_f32(1.), f16::from_f32(2.), f16::from_f32(3.), f16::from_f32(4.)]);
+ /// ```
+ #[must_use]
+ fn from_f32_slice(slice: &[f32]) -> Self;
+
+ /// Converts all of the elements of a `[f64]` slice into a new [`f16`] or [`bf16`] vector.
+ ///
+ /// The conversion operation is vectorized over the slice, meaning the conversion may be more
+ /// efficient than converting individual elements on some hardware that supports SIMD
+ /// conversions. See [crate documentation][crate] for more information on hardware conversion
+ /// support.
+ ///
+ /// # Examples
+ /// ```rust
+ /// # use half::prelude::*;
+ /// let float_values = [1., 2., 3., 4.];
+ /// let vec: Vec<f16> = Vec::from_f64_slice(&float_values);
+ ///
+ /// assert_eq!(vec, vec![f16::from_f64(1.), f16::from_f64(2.), f16::from_f64(3.), f16::from_f64(4.)]);
+ /// ```
+ #[must_use]
+ fn from_f64_slice(slice: &[f64]) -> Self;
+}
+
+/// Extensions to [`Vec<u16>`] to support reinterpret operations.
+///
+/// This trait is sealed and cannot be implemented outside of this crate.
+pub trait HalfBitsVecExt: private::SealedHalfBitsVec {
+ /// Reinterprets a vector of [`u16`] bits as a vector of [`f16`] or [`bf16`] numbers.
+ ///
+ /// `H` is the type to cast to, and must be either the [`f16`] or [`bf16`] type.
+ ///
+ /// This is a zero-copy operation. The reinterpreted vector has the same memory location as
+ /// `self`.
+ ///
+ /// # Examples
+ ///
+ /// ```rust
+ /// # use half::prelude::*;
+ /// let int_buffer = vec![f16::from_f32(1.).to_bits(), f16::from_f32(2.).to_bits(), f16::from_f32(3.).to_bits()];
+ /// let float_buffer = int_buffer.reinterpret_into::<f16>();
+ ///
+ /// assert_eq!(float_buffer, [f16::from_f32(1.), f16::from_f32(2.), f16::from_f32(3.)]);
+ /// ```
+ #[must_use]
+ fn reinterpret_into<H>(self) -> Vec<H>
+ where
+ H: crate::private::SealedHalf;
+}
+
+mod private {
+ use crate::{bf16, f16};
+ #[cfg(feature = "alloc")]
+ use alloc::vec::Vec;
+
+ pub trait SealedHalfFloatVec {}
+ impl SealedHalfFloatVec for Vec<f16> {}
+ impl SealedHalfFloatVec for Vec<bf16> {}
+
+ pub trait SealedHalfBitsVec {}
+ impl SealedHalfBitsVec for Vec<u16> {}
+}
+
+impl HalfFloatVecExt for Vec<f16> {
+ #[inline]
+ fn reinterpret_into(mut self) -> Vec<u16> {
+ // An f16 array has same length and capacity as u16 array
+ let length = self.len();
+ let capacity = self.capacity();
+
+ // Actually reinterpret the contents of the Vec<f16> as u16,
+ // knowing that structs are represented as only their members in memory,
+ // which is the u16 part of `f16(u16)`
+ let pointer = self.as_mut_ptr() as *mut u16;
+
+ // Prevent running a destructor on the old Vec<u16>, so the pointer won't be deleted
+ mem::forget(self);
+
+ // Finally construct a new Vec<f16> from the raw pointer
+ // SAFETY: We are reconstructing full length and capacity of original vector,
+ // using its original pointer, and the size of elements are identical.
+ unsafe { Vec::from_raw_parts(pointer, length, capacity) }
+ }
+
+ #[allow(clippy::uninit_vec)]
+ fn from_f32_slice(slice: &[f32]) -> Self {
+ let mut vec = Vec::with_capacity(slice.len());
+ // SAFETY: convert will initialize every value in the vector without reading them,
+ // so this is safe to do instead of double initialize from resize, and we're setting it to
+ // same value as capacity.
+ unsafe { vec.set_len(slice.len()) };
+ vec.convert_from_f32_slice(slice);
+ vec
+ }
+
+ #[allow(clippy::uninit_vec)]
+ fn from_f64_slice(slice: &[f64]) -> Self {
+ let mut vec = Vec::with_capacity(slice.len());
+ // SAFETY: convert will initialize every value in the vector without reading them,
+ // so this is safe to do instead of double initialize from resize, and we're setting it to
+ // same value as capacity.
+ unsafe { vec.set_len(slice.len()) };
+ vec.convert_from_f64_slice(slice);
+ vec
+ }
+}
+
+impl HalfFloatVecExt for Vec<bf16> {
+ #[inline]
+ fn reinterpret_into(mut self) -> Vec<u16> {
+ // An f16 array has same length and capacity as u16 array
+ let length = self.len();
+ let capacity = self.capacity();
+
+ // Actually reinterpret the contents of the Vec<f16> as u16,
+ // knowing that structs are represented as only their members in memory,
+ // which is the u16 part of `f16(u16)`
+ let pointer = self.as_mut_ptr() as *mut u16;
+
+ // Prevent running a destructor on the old Vec<u16>, so the pointer won't be deleted
+ mem::forget(self);
+
+ // Finally construct a new Vec<f16> from the raw pointer
+ // SAFETY: We are reconstructing full length and capacity of original vector,
+ // using its original pointer, and the size of elements are identical.
+ unsafe { Vec::from_raw_parts(pointer, length, capacity) }
+ }
+
+ #[allow(clippy::uninit_vec)]
+ fn from_f32_slice(slice: &[f32]) -> Self {
+ let mut vec = Vec::with_capacity(slice.len());
+ // SAFETY: convert will initialize every value in the vector without reading them,
+ // so this is safe to do instead of double initialize from resize, and we're setting it to
+ // same value as capacity.
+ unsafe { vec.set_len(slice.len()) };
+ vec.convert_from_f32_slice(slice);
+ vec
+ }
+
+ #[allow(clippy::uninit_vec)]
+ fn from_f64_slice(slice: &[f64]) -> Self {
+ let mut vec = Vec::with_capacity(slice.len());
+ // SAFETY: convert will initialize every value in the vector without reading them,
+ // so this is safe to do instead of double initialize from resize, and we're setting it to
+ // same value as capacity.
+ unsafe { vec.set_len(slice.len()) };
+ vec.convert_from_f64_slice(slice);
+ vec
+ }
+}
+
+impl HalfBitsVecExt for Vec<u16> {
+ // This is safe because all traits are sealed
+ #[inline]
+ fn reinterpret_into<H>(mut self) -> Vec<H>
+ where
+ H: crate::private::SealedHalf,
+ {
+ // An f16 array has same length and capacity as u16 array
+ let length = self.len();
+ let capacity = self.capacity();
+
+ // Actually reinterpret the contents of the Vec<u16> as f16,
+ // knowing that structs are represented as only their members in memory,
+ // which is the u16 part of `f16(u16)`
+ let pointer = self.as_mut_ptr() as *mut H;
+
+ // Prevent running a destructor on the old Vec<u16>, so the pointer won't be deleted
+ mem::forget(self);
+
+ // Finally construct a new Vec<f16> from the raw pointer
+ // SAFETY: We are reconstructing full length and capacity of original vector,
+ // using its original pointer, and the size of elements are identical.
+ unsafe { Vec::from_raw_parts(pointer, length, capacity) }
+ }
+}
+
+#[cfg(test)]
+mod test {
+ use super::{HalfBitsVecExt, HalfFloatVecExt};
+ use crate::{bf16, f16};
+ #[cfg(all(feature = "alloc", not(feature = "std")))]
+ use alloc::vec;
+
+ #[test]
+ fn test_vec_conversions_f16() {
+ let numbers = vec![f16::E, f16::PI, f16::EPSILON, f16::FRAC_1_SQRT_2];
+ let bits = vec![
+ f16::E.to_bits(),
+ f16::PI.to_bits(),
+ f16::EPSILON.to_bits(),
+ f16::FRAC_1_SQRT_2.to_bits(),
+ ];
+ let bits_cloned = bits.clone();
+
+ // Convert from bits to numbers
+ let from_bits = bits.reinterpret_into::<f16>();
+ assert_eq!(&from_bits[..], &numbers[..]);
+
+ // Convert from numbers back to bits
+ let to_bits = from_bits.reinterpret_into();
+ assert_eq!(&to_bits[..], &bits_cloned[..]);
+ }
+
+ #[test]
+ fn test_vec_conversions_bf16() {
+ let numbers = vec![bf16::E, bf16::PI, bf16::EPSILON, bf16::FRAC_1_SQRT_2];
+ let bits = vec![
+ bf16::E.to_bits(),
+ bf16::PI.to_bits(),
+ bf16::EPSILON.to_bits(),
+ bf16::FRAC_1_SQRT_2.to_bits(),
+ ];
+ let bits_cloned = bits.clone();
+
+ // Convert from bits to numbers
+ let from_bits = bits.reinterpret_into::<bf16>();
+ assert_eq!(&from_bits[..], &numbers[..]);
+
+ // Convert from numbers back to bits
+ let to_bits = from_bits.reinterpret_into();
+ assert_eq!(&to_bits[..], &bits_cloned[..]);
+ }
+}
projects / platform / upstream / rust-half.git / commitdiff