Merging upstream version 1.71.1+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 217 insertions, 0 deletions

diff --git a/vendor/half/src/lib.rs b/vendor/half/src/lib.rs
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+//! 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.
+//!
+//! # 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,
+    missing_debug_implementations,
+    trivial_numeric_casts,
+    future_incompatible
+)]
+#![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/1.8.2")]
+#![doc(test(attr(deny(warnings), allow(unused))))]
+#![cfg_attr(docsrs, feature(doc_cfg))]
+
+#[cfg(feature = "alloc")]
+extern crate alloc;
+
+mod bfloat;
+mod binary16;
+#[cfg(feature = "num-traits")]
+mod num_traits;
+
+pub mod slice;
+#[cfg(feature = "alloc")]
+#[cfg_attr(docsrs, doc(cfg(feature = "alloc")))]
+pub mod vec;
+
+pub use bfloat::bf16;
+#[doc(hidden)]
+#[allow(deprecated)]
+pub use binary16::consts;
+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,
+        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 {}
+}