Revert recent changes to dead code analysis
This is a revert to recent changes to dead code analysis, namely:
* efdf219 Rollup merge of #128104 - mu001999-contrib:fix/128053, r=petrochenkov
* a70dc297a8 Rollup merge of #127017 - mu001999-contrib:dead/enhance, r=pnkfelix
* 31fe9628cf Rollup merge of #127107 - mu001999-contrib:dead/enhance-2, r=pnkfelix
* 2724aeaaeb Rollup merge of #126618 - mu001999-contrib:dead/enhance, r=pnkfelix
* 977c5fd419 Rollup merge of #126315 - mu001999-contrib:fix/126289, r=petrochenkov
* 13314df21b Rollup merge of #125572 - mu001999-contrib:dead/enhance, r=pnkfelix
There is an additional change stacked on top, which suppresses false-negatives that were masked by this work. I believe the functions that are touched in that code are legitimately unused functions and the types are not reachable since this `AnonPipe` type is not publically reachable -- please correct me if I'm wrong cc `@NobodyXu` who added these in ##127153.
Some of these reverts (#126315 and #126618) are only included because it makes the revert apply cleanly, and I think these changes were only done to fix follow-ups from the other PRs?
I apologize for the size of the PR and the churn that it has on the codebase (and for reverting `@mu001999's` work here), but I'm putting this PR up because I am concerned that we're making ad-hoc changes to fix bugs that are fallout of these PRs, and I'd like to see these changes reimplemented in a way that's more separable from the existing dead code pass. I am happy to review any code to reapply these changes in a more separable way.
cc `@mu001999`
r? `@pnkfelix`
Fixes#128272Fixes#126169
Added SHA512, SM3, SM4 target-features and `sha512_sm_x86` feature gate
This is an effort towards #126624. This adds support for these 3 target-features and introduces the feature flag `sha512_sm_x86`, which would gate these target-features and the yet-to-be-implemented detection and intrinsics in stdarch.
Rewrite binary search implementation
This PR builds on top of #128250, which should be merged first.
This restores the original binary search implementation from #45333 which has the nice property of having a loop count that only depends on the size of the slice. This, along with explicit conditional moves from #128250, means that the entire binary search loop can be perfectly predicted by the branch predictor.
Additionally, LLVM is able to unroll the loop when the slice length is known at compile-time. This results in a very compact code sequence of 3-4 instructions per binary search step and zero branches.
Fixes#53823Fixes#115271
raw_eq: using it on bytes with provenance is not UB (outside const-eval)
The current behavior of raw_eq violates provenance monotonicity. See https://github.com/rust-lang/rust/pull/124921 for an explanation of provenance monotonicity. It is violated in raw_eq because comparing bytes without provenance is well-defined, but adding provenance makes the operation UB.
So remove the no-provenance requirement from raw_eq. However, the requirement stays in-place for compile-time invocations of raw_eq, that indeed cannot deal with provenance.
Cc `@rust-lang/opsem`
Due to a LLVM bug, `f128` math functions link successfully but LLVM
chooses the wrong symbols (`long double` symbols rather than those for
binary128).
Since this is a notable problem that may surprise a number of users, add
a note about it.
Link: https://github.com/llvm/llvm-project/issues/44744
`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`).
- Use if the implementation of [`Ord`] for `T`
language
- Link to total order wiki page
- Rework total order help and examples
- Improve language to be more precise and less
prone to misunderstandings.
- Fix usage of `sort_unstable_by` in `sort_by`
example
- Fix missing author mention
- Use more consistent example input for sort
- Use more idiomatic assert_eq! in examples
- Use more natural "comparison function" language
instead of "comparator function"
This restores the original binary search implementation from #45333
which has the nice property of having a loop count that only depends on
the size of the slice. This, along with explicit conditional moves
from #128250, means that the entire binary search loop can be perfectly
predicted by the branch predictor.
Additionally, LLVM is able to unroll the loop when the slice length is
known at compile-time. This results in a very compact code sequence of
3-4 instructions per binary search step and zero branches.
Fixes#53823
Add `select_unpredictable` to force LLVM to use CMOV
Since https://reviews.llvm.org/D118118, LLVM will no longer turn CMOVs into branches if it comes from a `select` marked with an `unpredictable` metadata attribute.
This PR introduces `core::intrinsics::select_unpredictable` which emits such a `select` and uses it in the implementation of `binary_search_by`.
Clean and enable `rustdoc::unescaped_backticks` for `core/alloc/std/test/proc_macro`
I am not sure if the lint is supposed to be "ready enough" (since it is `allow` by default), but it does catch a couple issues in `core` (`alloc`, `std`, `test` and `proc_macro` are already clean), so I propose making it `warn` in all the crates rendered in the website.
Cc: `@GuillaumeGomez`
There are only 3 cases across the crates rendered in the website (`core`,
`alloc`, `std`, `proc_macro` and `test`), and they are all in `core`.
Clean them up, so that the lint can be enabled in the next commit.
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Add links from `assert_eq!` docs to `debug_assert_eq!`, etc.
This adds information and links from the docs for the following macros to their debug-only versions:
* `assert_eq!`
* `assert_ne!`
* `assert_matches!`
This matches the existing documentation for the `assert!` macro.
Stabilize `const_waker`
Closes: https://github.com/rust-lang/rust/issues/102012.
For `local_waker` and `context_ext` related things, I just ~~moved them to dedicated feature gates and reused their own tracking issue (maybe it's better to open a new one later, but at least they should not be tracked under https://github.com/rust-lang/rust/issues/102012 from the beginning IMO.)~~ reused their own feature gates as suggested by ``@tgross35.``
``@rustbot`` label: +T-libs-api
r? libs-api
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.
Since https://reviews.llvm.org/D118118, LLVM will no longer turn CMOVs
into branches if it comes from a `select` marked with an `unpredictable`
metadata attribute.
This PR introduces `core::intrinsics::select_unpredictable` which emits
such a `select` and uses it in the implementation of `binary_search_by`.
from_ref, from_mut: clarify documentation
This was brought up [here](https://github.com/rust-lang/rust/issues/56604#issuecomment-2143193486). The domain of quantification is generally always constrained by the type in the type signature, and I am not sure it's always worth spelling that out explicitly as that makes things exceedingly verbose. But since this was explicitly brought up, let's clarify.
The new sort implementations have the ability to
detect Ord violations in many cases. This commit
improves the message in a way that should help
users realize what went wrong in their program.
Always set `result` during `finish()` in debug builders
Most functions for format builders set `self.result` after writing strings. This ensures that any further writing fails immediately rather than trying to write again.
A few `.finish()` methods and the `.finish_non_exhaustive` did have this same behavior, so update the remaining `.finish()` methods to make it consistent here.
