Use `nuw` when calculating slice lengths from `Range`s
An `assume` would definitely not be worth it, but since the flag is almost free we might as well tell LLVM this, especially on `_unchecked` calls where there's no obvious way for it to deduce it.
(Today neither safe nor unsafe indexing gets it: <https://rust.godbolt.org/z/G1jYT548s>)
Add `round_ties_even` to `f32` and `f64`
Tracking issue: #96710
Redux of #82273. See also #55107
Adds a new method, `round_ties_even`, to `f32` and `f64`, that rounds the float to the nearest integer , rounding halfway cases to the number with an even least significant bit. Uses the `roundeven` LLVM intrinsic to do this.
Of the five IEEE 754 rounding modes, this is the only one that doesn't already have a round-to-integer function exposed by Rust (others are `round`, `floor`, `ceil`, and `trunc`). Ties-to-even is also the rounding mode used for int-to-float and float-to-float `as` casts, as well as float arithmentic operations. So not having an explicit rounding method for it seems like an oversight.
Bikeshed: this PR currently uses `round_ties_even` for the name of the method. But maybe `round_ties_to_even` is better, or `round_even`, or `round_to_even`?
Remove `allow(potential_query_instability)` from `borrowck`
cc #84447
Replace uses of `FxHash*` with `FxIndex*`. One `#[allow]` for a HashMap in an external crate but the output is sorted afterwards.
fix multiple issues when promoting type-test subject
Multiple interdependent fixes. See linked issues for a short description of each.
When Promoting a type-test `T: 'a` from within the closure back to its parent function, there are a couple pre-existing bugs and limitations. They were exposed by the recent changes to opaque types because the type-test subject (`T`) is no longer a simple ParamTy.
Commit 1:
Fixes#108635Fixes#107426
Commit 2:
Fixes#108639
Commit 3:
Fixes#107516
Rollup of 8 pull requests
Successful merges:
- #107801 (const_eval: `implies_by` in `rustc_const_unstable`)
- #108750 (Fix `ObligationCtxt::sub`)
- #108780 (Add regression tests for issue 70919)
- #108786 (Check for free regions in MIR validation)
- #108790 (Do not ICE when interpreting a cast between non-monomorphic types)
- #108803 (Do not ICE when failing to normalize in ConstProp.)
- #108807 (Emit the suspicious_auto_trait_impls for negative impls as well)
- #108812 (Add regression test for #98444)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Do not ICE when failing to normalize in ConstProp.
There is no reason to delay a bug there, as we bubble up the failure as TooGeneric.
Fixes https://github.com/rust-lang/rust/issues/97728
Check for free regions in MIR validation
This turns https://github.com/rust-lang/rust/issues/108720 into a MIR validation failure that will reproduce without debug-assertions enabled.
```
error: internal compiler error: broken MIR in Item(WithOptConstParam { did: DefId(0:296 ~ futures_util[3805]::future::future::remote_handle::{impl#3}::poll), const_param_did: None }) (after pass ScalarReplacementOfAggregates) at bb0[0]:
Free regions in optimized runtime-post-cleanup MIR
--> /home/ben/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-util-0.3.26/src/future/future/remote_handle.rs:96:13
|
96 | let this = self.project();
| ^^^^
```
Add regression tests for issue 70919
Desugaring DropAndReplace at MIR build (#107844) fixed#70919.
Add regressions tests, borrowed from #102078, to ensure we check for this in the future.
cc ``@Aaron1011``
const_eval: `implies_by` in `rustc_const_unstable`
Fixes#107605.
Extend support for `implies_by` (from `#[stable]` and `#[unstable]`) to `#[rustc_const_stable]` and `#[rustc_const_unstable]`.
cc ``@steffahn``
Allow using `bool` instead of `Option<()>` in diagnostics
~~Disallow the unit type for `#[help]`, `#[note]` etc, instead using `bool` to express optional annotations without a span which I believe is more intuitive.~~
~~Test output ordering has changed in a few places, where a field was of type `()` and the annotation has been moved to the struct itself. If any of these changes are an issue, this can be restricted to allowing specifically `()`, and not `Option<()>`~~
~~Actual changes here: https://github.com/rust-lang/rust/pull/108402/files#diff-815b1d8debfc564112bd51093791d7c3f2ee288a37a8f5c0e89c11d1f609b4c0~~
Allows using `bool` in derive diagnostics to indicate an optional subdiagnostic without a span, where previously `Option<()>` had to be used
`@rustbot` label +A-diagnostics
Rollup of 7 pull requests
Successful merges:
- #108244 (Add test for semicolon recovery ICE)
- #108746 (Don't project to RPITIT that has no default value)
- #108764 (Tweaks to -Zdrop-tracking-mir)
- #108770 (Improve documentation and argument naming of some TyCtxt methods)
- #108773 (x fmt: Only check modified files locally)
- #108775 (Use the correct bound vars in return type suggestion.)
- #108776 (Make `x test tidy` less noisy)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
An `assume` would definitely not be worth it, but since the flag is almost free we might as well tell LLVM this, especially on `_unchecked` calls where there's no obvious way for it to deduce it.
(Today neither safe nor unsafe indexing gets it: <https://rust.godbolt.org/z/G1jYT548s>)
Use `partial_cmp` to implement tuple `lt`/`le`/`ge`/`gt`
In today's implementation, `(A, B)::gt` contains calls to *both* `A::eq` *and* `A::gt`.
That's fine for primitives, but for things like `String`s it's kinda weird -- `(String, usize)::gt` has a call to both `bcmp` and `memcmp` (<https://rust.godbolt.org/z/7jbbPMesf>) because when `bcmp` says the `String`s aren't equal, it turns around and calls `memcmp` to find out which one's bigger.
This PR changes the implementation to instead implement `(A, …, C, Z)::gt` using `A::partial_cmp`, `…::partial_cmp`, `C::partial_cmp`, and `Z::gt`. (And analogously for `lt`, `le`, and `ge`.) That way expensive comparisons don't need to be repeated.
Technically this is an observable change on stable, so I've marked it `needs-fcp` + `T-libs-api` and will
r? rust-lang/libs-api
I'm hoping that this will be non-controversial, however, since it's very similar to the observable changes that were made to the derives (#81384#98655) -- like those, this only changes behaviour if a type overrode behaviour in a way inconsistent with the rules for the various traits involved.
(The first commit here is #108156, adding the codegen test, which I used to make sure this doesn't regress behaviour for primitives.)
Zulip conversation about this change: <https://rust-lang.zulipchat.com/#narrow/stream/219381-t-libs/topic/.60.3E.60.20on.20Tuples/near/328392927>.
