Remove support for `extern "rust-intrinsic"` blocks
Part of rust-lang/rust#132735
Looked manageable and there didn't appear to have been progress in the last two weeks,
so decided to give it a try.
Add new `PatKind::Missing` variants
To avoid some ugly uses of `kw::Empty` when handling "missing" patterns, e.g. in bare fn tys. Helps with #137978. Details in the individual commits.
r? ``@oli-obk``
style guide: add let-chain rules
Reopens#110568
refs #53667 and I suppose #132833 as well
This reflects the style rules that the style team had already agreed upon back in 2023, with the addition of literals in the lhs being permissible for single line formatting, and the removal of unnecessary language/example snippets around non-`&&` operators that was a small hiccup in the original PR.
It also reflects current formatting behavior implemented in rustfmt (though note that the adjustment to include literals has been implemented & merged, but is still pending a sync to nightly)
Add `*_value` methods to proc_macro lib
This is the (re-)implementation of https://github.com/rust-lang/libs-team/issues/459.
It allows to get the actual value (unescaped) of the different string literals.
It was originally done in https://github.com/rust-lang/rust/pull/136355 but it broke the artifacts build so we decided to move the crate to crates.io to go around this limitation.
Part of https://github.com/rust-lang/rust/issues/136652.
Considering this is a copy-paste of the originally approved PR, no need to go through the whole process again. \o/
r? `@Urgau`
Only build `rust_test_helpers` for `{incremental,ui}` test suites
Only build `rust_test_helpers` for `{incremental,ui}` test suites.
Context: Trying to see what test suites actually need `rust_test_helpers`, because this was causing unnecessary local failures when trying to run `./x test tests/run-make --target=wasm32-unknown-unknown` when `run-make` tests don't need `rust_test_helpers` at all.
r? `@ghost`
try-job: armhf-gnu
try-job: test-various
try-job: x86_64-apple-1
try-job: aarch64-apple
try-job: x86_64-msvc-1
try-job: i686-msvc-1
try-job: x86_64-mingw-1
try-job: i686-mingw-1
tidy: Fix paths to `coretests` and `alloctests`
Following `#135937` and `#136642`, tests for core and alloc are in coretests and alloctests. Fix tidy to lint for the new paths. Also, update comments referring to the old locations.
Some context for changes which don't match that pattern:
- `library/std/src/thread/local/dynamic_tests.rs` and `library/std/src/sync/mpsc/sync_tests.rs` were moved under `library/std/tests/` in 332fb7e6f1 (Move std::thread_local unit tests to integration tests, 2025-01-17) and b8ae372e48 (Move std::sync unit tests to integration tests, 2025-01-17), respectively, so are no longer special cases.
- There never was a `library/core/tests/fmt.rs` file. That comment previously referred to `src/test/ui/ifmt.rs`, which was folded into `library/alloc/tests/fmt.rs` in 949c96660c (move format! interface tests, 2020-09-08).
Now, the only matches for `(alloc|core)/tests` are in `compiler/rustc_codegen_{cranelift,gcc}/patches`. I don't know why CI hasn't broken because those patches can't apply. Or maybe they somehow still can apply?
r? `@bjorn3`
Following `#135937` and `#136642`, tests for core and alloc are in
coretests and alloctests. Fix tidy to lint for the new paths. Also,
update comments referring to the old locations.
Some context for changes which don't match that pattern:
* library/std/src/thread/local/dynamic_tests.rs and
library/std/src/sync/mpsc/sync_tests.rs were moved under
library/std/tests/ in 332fb7e6f1 (Move std::thread_local unit tests
to integration tests, 2025-01-17) and b8ae372e48 (Move std::sync unit
tests to integration tests, 2025-01-17), respectively, so are no
longer special cases.
* There never was a library/core/tests/fmt.rs file. That comment
previously referred to src/test/ui/ifmt.rs, which was folded into
library/alloc/tests/fmt.rs in 949c96660c (move format! interface
tests, 2020-09-08).
Move `fd` into `std::sys`
Move platform definitions of `fd` into `std::sys`, as part of https://github.com/rust-lang/rust/issues/117276.
Unlike other modules directly under `std::sys`, this is only available on some platforms and I have not provided a fallback abstraction for unsupported platforms. That is similar to how `std::os::fd` is gated to only supported platforms.
Also, fix the `unsafe_op_in_unsafe_fn` lint, which was allowed for the Unix fd impl. Since macro expansions from `std::sys::pal::unix::weak` trigger this lint, fix it there too.
cc `@joboet,` `@ChrisDenton`
try-job: x86_64-gnu-aux
Rustdoc: typecheck settings.js
This makes the file fully typechecked with no instances of ``````@ts-expect-error`````` and no type casts.
r? `````@notriddle`````
Expose algebraic floating point intrinsics
# Problem
A stable Rust implementation of a simple dot product is 8x slower than C++ on modern x86-64 CPUs. The root cause is an inability to let the compiler reorder floating point operations for better vectorization.
See https://github.com/calder/dot-bench for benchmarks. Measurements below were performed on a i7-10875H.
### C++: 10us ✅
With Clang 18.1.3 and `-O2 -march=haswell`:
<table>
<tr>
<th>C++</th>
<th>Assembly</th>
</tr>
<tr>
<td>
<pre lang="cc">
float dot(float *a, float *b, size_t len) {
#pragma clang fp reassociate(on)
float sum = 0.0;
for (size_t i = 0; i < len; ++i) {
sum += a[i] * b[i];
}
return sum;
}
</pre>
</td>
<td>
<img src="https://github.com/user-attachments/assets/739573c0-380a-4d84-9fd9-141343ce7e68" />
</td>
</tr>
</table>
### Nightly Rust: 10us ✅
With rustc 1.86.0-nightly (8239a37f9) and `-C opt-level=3 -C target-feature=+avx2,+fma`:
<table>
<tr>
<th>Rust</th>
<th>Assembly</th>
</tr>
<tr>
<td>
<pre lang="rust">
fn dot(a: &[f32], b: &[f32]) -> f32 {
let mut sum = 0.0;
for i in 0..a.len() {
sum = fadd_algebraic(sum, fmul_algebraic(a[i], b[i]));
}
sum
}
</pre>
</td>
<td>
<img src="https://github.com/user-attachments/assets/9dcf953a-2cd7-42f3-bc34-7117de4c5fb9" />
</td>
</tr>
</table>
### Stable Rust: 84us ❌
With rustc 1.84.1 (e71f9a9a9) and `-C opt-level=3 -C target-feature=+avx2,+fma`:
<table>
<tr>
<th>Rust</th>
<th>Assembly</th>
</tr>
<tr>
<td>
<pre lang="rust">
fn dot(a: &[f32], b: &[f32]) -> f32 {
let mut sum = 0.0;
for i in 0..a.len() {
sum += a[i] * b[i];
}
sum
}
</pre>
</td>
<td>
<img src="https://github.com/user-attachments/assets/936a1f7e-33e4-4ff8-a732-c3cdfe068dca" />
</td>
</tr>
</table>
# Proposed Change
Add `core::intrinsics::f*_algebraic` wrappers to `f16`, `f32`, `f64`, and `f128` gated on a new `float_algebraic` feature.
# Alternatives Considered
https://github.com/rust-lang/rust/issues/21690 has a lot of good discussion of various options for supporting fast math in Rust, but is still open a decade later because any choice that opts in more than individual operations is ultimately contrary to Rust's design principles.
In the mean time, processors have evolved and we're leaving major performance on the table by not supporting vectorization. We shouldn't make users choose between an unstable compiler and an 8x performance hit.
# References
* https://github.com/rust-lang/rust/issues/21690
* https://github.com/rust-lang/libs-team/issues/532
* https://github.com/rust-lang/rust/issues/136469
* https://github.com/calder/dot-bench
* https://www.felixcloutier.com/x86/vfmadd132ps:vfmadd213ps:vfmadd231ps
try-job: x86_64-gnu-nopt
try-job: x86_64-gnu-aux
Fix 2024 edition doctest panic output
Fixes#137970.
The problem was that the output was actually displayed by rustc itself because we're exiting with `Result<(), String>`, and the display is really not great. So instead, we get the output, we print it and then we return an `ExitCode`.
r? ````@aDotInTheVoid````
Demote i686-pc-windows-gnu to Tier 2
In accordance with [RFC 3771](https://github.com/rust-lang/rfcs/pull/3771). FCP has been completed.
tracking issue #138422
I also added a stub doc page for the target and renamed the windows-gnullvm page for consistency.
compiletest: Encapsulate all of the code that touches libtest
Compiletest currently relies on unstable libtest APIs in order to actually execute tests. That's unfortunate, but removing the dependency isn't trivial.
However, we can make a small step towards removing the libtest dependency by encapsulating the libtest interactions into a single dedicated module. That makes it easier to see what parts of libtest are actually used.
---
As a side-effect of moving the `test_opts` function into that dedicated module, this PR also ends up allowing `--fail-fast` to be passed on the command line, instead of requiring an environment variable.
---
There is still (at least) one other aspect of the libtest dependency that this PR does not address, namely the fact that we rely on libtest's output capture (via unstable std APIs) to capture the output that we print during individual tests. I hope to do something about that at some point.
r? jieyouxu
