Mark `u8::make_ascii_uppercase` and `u8::make_ascii_lowercase` as const.
Relevant tracking issue: #130698
This PR extends #130697 by also marking the `make_ascii_uppercase` and `make_ascii_lowercase` methods in `u8` as const.
The `const_char_make_ascii` feature gate is additionally renamed to `const_make_ascii`.
[Clippy] Get rid of most `std` `match_def_path` usage, swap to diagnostic items.
Part of https://github.com/rust-lang/rust-clippy/issues/5393.
This was going to remove all `std` paths, but `SeekFrom` has issues being cleanly replaced with a diagnostic item as the paths are for variants, which currently cannot be diagnostic items.
This also, as a last step, categories the paths to help with future path removals.
Improve documentation for <integer>::from_str_radix
Two improvements to the documentation:
- Document `-` as a valid character for signed integer destinations
- Make the documentation even more clear that extra whitespace and non-digit characters is invalid. Many other languages, e.g. c++, are very permissive in string to integer routines and simply try to consume as much as they can, ignoring the rest. This is trying to make the transition for developers who are used to the conversion semantics in these languages a bit easier.
simplify float::classify logic
I played around with the float-classify test in the hope of triggering x87 bugs by strategically adding `black_box`, and still the exact expression `@beetrees` suggested [here](https://github.com/rust-lang/rust/pull/129835#issuecomment-2325661597) remains the only case I found where we get the wrong result on x87. Curiously, this bug only occurs when MIR optimizations are enabled -- probably the extra inlining that does is required for LLVM to hit the right "bad" case in the backend. But even for that case, it makes no difference whether `classify` is implemented in the simple bit-pattern-based version or the more complicated version we had before.
Without even a single testcase that can distinguish our `classify` from the naive version, I suggest we switch to the naive version.
some const cleanup: remove unnecessary attributes, add const-hack indications
I learned that we use `FIXME(const-hack)` on top of the "const-hack" label. That seems much better since it marks the right place in the code and moves around with the code. So I went through the PRs with that label and added appropriate FIXMEs in the code. IMO this means we can then remove the label -- Cc ``@rust-lang/wg-const-eval.``
I also noticed some const stability attributes that don't do anything useful, and removed them.
r? ``@fee1-dead``
Rollup of 10 pull requests
Successful merges:
- #126452 (Implement raw lifetimes and labels (`'r#ident`))
- #129555 (stabilize const_float_bits_conv)
- #129594 (explain the options bootstrap passes to curl)
- #129677 (Don't build by-move body when async closure is tainted)
- #129847 (Do not call query to compute coroutine layout for synthetic body of async closure)
- #129869 (add a few more crashtests)
- #130009 (rustdoc-search: allow trailing `Foo ->` arg search)
- #130046 (str: make as_mut_ptr and as_bytes_mut unstably const)
- #130047 (Win: Add dbghelp to the list of import libraries)
- #130059 (Remove the unused `llvm-skip-rebuild` option from x.py)
r? `@ghost`
`@rustbot` modify labels: rollup
Two improvements to the documentation:
- Document `-` as a valid character for signed integer destinations
- Make the documentation even more clear that extra whitespace and non-digit characters is invalid. Many other
languages, e.g. c++, are very permissive in string to integer routines and simply try to consume as much as they can,
ignoring the rest. This is trying to make the transition for developers who are used to the conversion semantics in
these languages a bit easier.
* Use a lookup table for 8-bit integers and the Karatsuba square root
algorithm for larger integers.
* Include optimization hints that give the compiler the exact numeric
range of results.
Add implementations for `unbounded_shl`/`unbounded_shr`
Tracking Issue: https://github.com/rust-lang/rust/issues/129375
This implements `unbounded_shl` and `unbounded_shr` under the feature gate `unbounded_shifts`
Optimize integer `pow` by removing the exit branch
The branch at the end of the `pow` implementations is redundant with multiplication code already present in the loop. By rotating the exit check, this branch can be largely removed, improving code size and reducing instruction cache misses.
Testing on my machine (`x86_64`, 11th Gen Intel Core i5-1135G7 @ 2.40GHz), the `num::int_pow` benchmarks improve by some 40% for the unchecked operations and show some slight improvement for the checked operations as well.
Mark `{f32,f64}::{next_up,next_down,midpoint}` inline
Most float functions are marked `#[inline]` so any float symbols used by these functions only need to be provided if the function itself is used. RFL recently noticed that `next_up`, `next_down`, and `midpoint` for `f32` and `f64` are not inline, which causes linker errors when building with certain configurations <https://lore.kernel.org/all/20240806150619.192882-1-ojeda@kernel.org/>.
Add the missing attributes so the symbols should no longer be required.
Most float functions are marked `#[inline]` so any float symbols used by
these functions only need to be provided if the function itself is used.
RFL recently noticed that `next_up`, `next_down`, and `midpoint` for
`f32` and `f64` are not inline, which causes linker errors when building
with certain configurations [1].
Add the missing attributes so the symbols should no longer be required.
Cc: Gary Guo <gary@garyguo.net>
Reported-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/all/20240806150619.192882-1-ojeda@kernel.org/ [1]
Add `f16` and `f128` math functions
This adds intrinsics and math functions for `f16` and `f128` floating point types. Support is quite limited and some things are broken so tests don't run on many platforms, but this provides a starting point.
The "dragon" `flt2dec` algorithm uses multi-precision multiplication by
(sometimes large) powers of 10. It has precomputed some values to help
with these calculations.
BUT:
* There is no need to store powers of 10 and 2 * powers of 10: it is
trivial to compute the second from the first.
* We can save a chunk of memory by storing powers of 5 instead of powers
of 10 for the large powers (and just shifting by 2 as appropriate).
* This also slightly speeds up the routines (by ~1-3%) since the
intermediate products are smaller and the shift is cheap.
In this PR, we remove the unnecessary constants and do the necessary
adjustments.
Relevant benchmarks before (on my Threadripper 3970X, x86_64-unknown-linux-gnu):
```
num::flt2dec::bench_big_shortest 137.92/iter +/- 2.24
num::flt2dec::strategy:🐉:bench_big_exact_12 2135.28/iter +/- 38.90
num::flt2dec::strategy:🐉:bench_big_exact_3 904.95/iter +/- 10.58
num::flt2dec::strategy:🐉:bench_big_exact_inf 47230.33/iter +/- 320.84
num::flt2dec::strategy:🐉:bench_big_shortest 3915.05/iter +/- 51.37
```
and after:
```
num::flt2dec::bench_big_shortest 137.40/iter +/- 2.03
num::flt2dec::strategy:🐉:bench_big_exact_12 2101.10/iter +/- 25.63
num::flt2dec::strategy:🐉:bench_big_exact_3 873.86/iter +/- 4.20
num::flt2dec::strategy:🐉:bench_big_exact_inf 47468.19/iter +/- 374.45
num::flt2dec::strategy:🐉:bench_big_shortest 3877.01/iter +/- 45.74
```
`min`, `max`, and similar functions require external math routines. Add
these under the same gates as `std` math functions (`reliable_f16_math`
and `reliable_f128_math`).
add `is_multiple_of` for unsigned integer types
tracking issue: https://github.com/rust-lang/rust/issues/128101
This adds the `.is_multiple_of` method on unsigned integers.
Returns `true` if `self` is an integer multiple of `rhs`, and false otherwise.
This function is equivalent to `self % rhs == 0`, except that it will not panic for `rhs == 0`. Instead, `0.is_multiple_of(0) == true`, and for any non-zero `n`, `n.is_multiple_of(0) == false`.
Fix doc nits
Many tiny changes to stdlib doc comments to make them consistent (for example "Returns foo", rather than "Return foo"), adding missing periods, paragraph breaks, backticks for monospace style, and other minor nits.
