It was disabled because of pathological behaviour of LLVM in some
benchmarks. As of #77680, this has been fixed. The problem there was
that it caused pessimizations in some cases. These have now been fixed
as well.
Before, UnreachablePropagation removed all unreachable branches.
This was a pessimization, as it removed information about
reachability that was used later in the optimization pipeline.
For example, this code
```rust
pub enum Two { A, B }
pub fn identity(x: Two) -> Two {
match x {
Two::A => Two::A,
Two::B => Two::B,
}
}
```
basically has `switchInt() -> [0: 0, 1: 1, otherwise: unreachable]` for the match.
This allows it to be transformed into a simple `x`. If we remove the
unreachable branch, the transformation becomes illegal.
Rollup of 11 pull requests
Successful merges:
- #100556 (Clamp Function for f32 and f64)
- #100663 (Make slice::reverse const)
- #100697 ( Minor syntax and formatting update to doc comment on `find_vtable_types_for_unsizing`)
- #100760 (update test for LLVM change)
- #100761 (some general mir typeck cleanup)
- #100775 (rustdoc: Merge source code pages HTML elements together v2)
- #100813 (Add `/build-rust-analyzer/` to .gitignore)
- #100821 (Make some docs nicer wrt pointer offsets)
- #100822 (Replace most uses of `pointer::offset` with `add` and `sub`)
- #100839 (Make doc for stdin field of process consistent)
- #100842 (Add diagnostics lints to `rustc_transmute` module (zero diags))
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
rustdoc: strategic boxing to reduce the size of ItemKind and Type
The `Type` change redesigns `QPath` to box the entire data structure instead of boxing `self_type` and the `trait_`.
This reduces the size of several `ItemKind` variants, leaving `Impl` as the biggest variant. The `ItemKind` change boxes that variant's payload.
Replace most uses of `pointer::offset` with `add` and `sub`
As PR title says, it replaces `pointer::offset` in compiler and standard library with `pointer::add` and `pointer::sub`. This generally makes code cleaner, easier to grasp and removes (or, well, hides) integer casts.
This is generally trivially correct, `.offset(-constant)` is just `.sub(constant)`, `.offset(usized as isize)` is just `.add(usized)`, etc. However in some cases we need to be careful with signs of things.
r? ````@scottmcm````
_split off from #100746_
Replace most uses of `pointer::offset` with `add` and `sub`
As PR title says, it replaces `pointer::offset` in compiler and standard library with `pointer::add` and `pointer::sub`. This generally makes code cleaner, easier to grasp and removes (or, well, hides) integer casts.
This is generally trivially correct, `.offset(-constant)` is just `.sub(constant)`, `.offset(usized as isize)` is just `.add(usized)`, etc. However in some cases we need to be careful with signs of things.
r? ````@scottmcm````
_split off from #100746_
Make some docs nicer wrt pointer offsets
This PR replaces `pointer::offset` with `pointer::add` and similarly `.cast().wrapping_add().cast()` with `.wrapping_byte_add()` **in docs**.
r? ``````@scottmcm``````
_split off from #100746_
rustdoc: Merge source code pages HTML elements together v2
This is the follow-up of https://github.com/rust-lang/rust/pull/100429.
I strongly recommend to review it one commit at a time because otherwise it's a lot at once.
For these ones, on each page, I run this JS: `document.getElementsByTagName('*').length`. The goal is to count the number of DOM elements. I took some pages that seemed big, but don't hesitate to check some others. I also added the "starting point" because it's quite nice to see how much the page was reduced thanks to these two PRs.
| file name | before #100429 | before this PR | with this PR | diff |
|-|-|-|-|-|
| std/lib.rs.html (source link on std crate page) | 3455 | 2332 | 1772 | 24% |
| alloc/vec/mod.rs.html (source on Vec type page) | 11012 | 5982 | 5833 | 2.5% |
| alloc/string.rs.html (source on String type page) | 10800 | 6010 | 5822 | 3.2% |
| std/sync/mutex.rs.html (source on Mutex type page) | 2953 | 2041 | 2038 | 0.1% |
So unsurprisingly, the more attributes you have, the bigger the difference.
You can test it [here](https://rustdoc.crud.net/imperio/reduce-span-v2/src/std/lib.rs.html).
cc ``````@jsha``````
r? ``````@notriddle``````
some general mir typeck cleanup
this pr contains the parts of #95763 which already work correctly.
the remaining commits of that PR have some issues which are more complex to fix.
r? types
Minor syntax and formatting update to doc comment on `find_vtable_types_for_unsizing`
I noticed the code examples on this function weren't formatted as code, and also the that the syntax for trait objects was out of date (or just incorrect). This should bring it up to date.
Clamp Function for f32 and f64
I thought the clamp function could use a little improvement for readability purposes. The function now returns early in order to skip the extra bound checks.
If there was a reason for binding `self` to `x` or if this code is incorrect, please correct me :)
