Since [1], `compiler-builtins` makes a certain set of math symbols
weakly available on all platforms. This means we can begin exposing some
of the related functions in `core`, so begin this process here.
It is not possible to provide inherent methods in both `core` and `std`
while giving them different stability gates, so standalone functions are
added instead. This provides a way to experiment with the functionality
while unstable; once it is time to stabilize, they can be converted to
inherent.
For `f16` and `f128`, everything is unstable so we can move the inherent
methods.
The following are included to start:
* floor
* ceil
* round
* round_ties_even
* trunc
* fract
* mul_add
* div_euclid
* rem_euclid
* powi
* sqrt
* abs_sub
* cbrt
These mirror the set of functions that we have in `compiler-builtins`
since [1].
Tracking issue: https://github.com/rust-lang/rust/issues/137578
[1]: https://github.com/rust-lang/compiler-builtins/pull/763
New compiler configuration has been introduced that is designed to
replace the build script configuration `reliable_f16`, `reliable_f128`,
`reliable_f16_math`, and `reliable_f128_math`. Do this replacement here,
which allows us to clean up `std`'s build script.
All tests are gated by `#[cfg(bootstrap)]` rather than doing a more
complicated `cfg(bootstrap)` / `cfg(not(bootstrap))` split since the
next beta split is within two weeks.
Document results of non-positive logarithms
The integer versions of logarithm functions panic on non-positive numbers. The floating point versions have different, undocumented behaviour (-inf on 0, NaN on <0). This PR documents that.
try-job: aarch64-gnu
intrinsics: unify rint, roundeven, nearbyint in a single round_ties_even intrinsic
LLVM has three intrinsics here that all do the same thing (when used in the default FP environment). There's no reason Rust needs to copy that historically-grown mess -- let's just have one intrinsic and leave it up to the LLVM backend to decide how to lower that.
Suggested by `@hanna-kruppe` in https://github.com/rust-lang/rust/issues/136459; Cc `@tgross35`
try-job: test-various
In 136324 the doctest for `f16::erf()` was gated with
`reliable_f16_math`. Add the same gate on `f16::erfc()` to
avoid:
rust_out.71e2e529d20ea47d-cgu.0:\
(.text._ZN8rust_out4main43_doctest_main_library_std_src_f16_rs_1321_017h485f3ffe6bf2a981E+0x38): \
undefined reference to `__gnu_h2f_ieee'
on MIPS (and maybe other architectures).
Move some std tests to integration tests
Unit tests directly inside of standard library crates require a very fragile way of building that is hard to reproduce outside of bootstrap.
Follow up to https://github.com/rust-lang/rust/pull/133859
Searching "fma" in the Rust documentation returns results for
`intrinsics::fma*`, but does not point to the user-facing `mul_add`. Add
aliases for `fma*` and the IEEE operation name `fusedMultiplyAdd`. Add
the IEEE name to `sqrt` as well, `squareRoot`.
Some float methods are now `const fn` under the `const_float_methods` feature gate.
In order to support `min`, `max`, `abs` and `copysign`, the implementation of some intrinsics had to be moved from Miri to rustc_const_eval.
This adds missing functions for math operations on the new float types.
Platform support is pretty spotty at this point, since even platforms
with generally good support can be missing math functions.
`std/build.rs` is updated to reflect this.
This adds everything that was directly or transitively blocked on const
arithmetic for these types, which was recently merged.
Since const arithmetic is recent, most of these need to be gated by
`bootstrap`.
Anything that relies on intrinsics that are still missing is excluded.
