Matthias Krüger 789d168e13 Rollup merge of #91008 - Urgau:float-minimum-maximum, r=scottmcm ... Adds IEEE 754-2019 minimun and maximum functions for f32/f64 IEEE 754-2019 removed the `minNum` (`min` in Rust) and `maxNum` (`max` in Rust) operations in favor of the newly created `minimum` and `maximum` operations due to their [non-associativity](https://grouper.ieee.org/groups/msc/ANSI_IEEE-Std-754-2019/background/minNum_maxNum_Removal_Demotion_v3.pdf) that cannot be fix in a backwards compatible manner. This PR adds `fN::{minimun,maximum}` functions following the new rules. ### IEEE 754-2019 Rules > **minimum(x, y)** is x if x < y, y if y < x, and a quiet NaN if either operand is a NaN, according to 6.2. For this operation, −0 compares less than +0. Otherwise (i.e., when x = y and signs are the same) it is either x or y. > **maximum(x, y)** is x if x > y, y if y > x, and a quiet NaN if either operand is a NaN, according to 6.2. For this operation, +0 compares greater than −0. Otherwise (i.e., when x = y and signs are the same) it is either x or y. "IEEE Standard for Floating-Point Arithmetic," in IEEE Std 754-2019 (Revision of IEEE 754-2008) , vol., no., pp.1-84, 22 July 2019, doi: 10.1109/IEEESTD.2019.8766229. ### Implementation This implementation is inspired by the one in [`glibc` ](90f0ac10a7/math/s_fminimum_template.c) (it self derived from the C2X draft) expect that: - it doesn't use `copysign` because it's not available in `core` and also because `copysign` is unnecessary (we only want to check the sign, no need to create a new float) - it also prefer `other > self` instead of `self < other` like IEEE 754-2019 does I originally tried to implement them [using intrinsics](1d8aa13bc3) but LLVM [error out](https://godbolt.org/z/7sMrxW49a) when trying to lower them to machine intructions, GCC doesn't yet have built-ins for them, only cranelift support them nativelly (as it doesn't support the nativelly the old sementics). Helps with https://github.com/rust-lang/rust/issues/83984		2021-11-21 09:55:13 +01:00
..
benches	mv std libs to library/	2020-07-27 19:51:13 -05:00
primitive_docs	Add primitive documentation to libcore	2021-09-12 02:23:08 +00:00
src	Rollup merge of #91008 - Urgau:float-minimum-maximum, r=scottmcm	2021-11-21 09:55:13 +01:00
tests	Update aarch64 runtime feature detection tests	2021-08-03 12:07:56 +00:00
build.rs	std: Get the standard library compiling for wasm64	2021-11-10 08:35:42 -08:00
Cargo.toml	Update stdarch/dlmalloc	2021-11-10 08:35:43 -08:00