Rollup of 6 pull requests #151667

Zalathar · 2026-01-26T03:36:24Z

Successful merges:

Improve is_ascii performance on x86_64 with explicit SSE2 intrinsics #151611 (Improve is_ascii performance on x86_64 with explicit SSE2 intrinsics)
Add missing mut to pin.rs docs #150705 (Add missing mut to pin.rs docs)
compiletest: add implied needs-target-std for codegen mode tests unless annotated with #![no_std]/#![no_core] #151294 (compiletest: add implied needs-target-std for codegen mode tests unless annotated with #![no_std]/#![no_core])
Add a documentation remapping path scope for rustdoc usage #151589 (Add a documentation remapping path scope for rustdoc usage)
Fix broken WASIp1 reference link #151639 (Fix broken WASIp1 reference link)
Update sysinfo version to 0.38.0 #151645 (Update sysinfo version to 0.38.0)

Per my understanding, needed for mut access next line.

Use explicit SSE2 intrinsics to avoid LLVM's broken AVX-512 auto-vectorization which generates ~31 kshiftrd instructions. Performance - AVX-512: 34-48x faster - SSE2: 1.5-2x faster Improves on earlier pr

The SSE2 helper function is not inlined across crate boundaries, so we cannot verify the codegen in an assembly test. The fix is still verified by the absence of performance regression.

…tests by default A `codegen-llvm` test (and other codegen test mode tests) will now by default have an implied `//@ needs-target-std` directive, *unless* the test explicitly has an `#![no_std]`/`#![no_core]` attribute which disables this implied behavior. - When a test has both `#![no_std]`/`#![no_core]` and `//@ needs-target-std`, the explicit `//@ needs-target-std` directive will cause the test to be ignored for targets that do not support std still. This is to make it easier to test out-of-tree targets / custom targets (and targets not tested in r-l/r CI) without requiring target maintainers to do a bunch of manual `//@ needs-target-std` busywork. Co-authored-by: Edoardo Marangoni <ecmm@anche.no>

@folkertdev

…erformance, r=folkertdev Improve is_ascii performance on x86_64 with explicit SSE2 intrinsics # Summary Improves `slice::is_ascii` performance for SSE2 target roughly 1.5-2x on larger inputs. AVX-512 keeps similiar performance characteristics. This is building on the work already merged in rust-lang#151259. In particular this PR improves the default SSE2 performance, I don't consider this a temporary fix anymore. Thanks to @folkertdev for pointing me to consider `as_chunk` again. # The implementation: - Uses 64-byte chunks with 4x 16-byte SSE2 loads OR'd together - Extracts the MSB mask with a single `pmovmskb` instruction - Falls back to usize-at-a-time SWAR for inputs < 64 bytes # Performance impact (vs before rust-lang#151259): - AVX-512: 34-48x faster - SSE2: 1.5-2x faster <details> <summary>Benchmark Results (click to expand)</summary> Benchmarked on AMD Ryzen 9 9950X (AVX-512 capable). Values show relative performance (1.00 = fastest). Tops out at 139GB/s for large inputs. ### early_non_ascii | Input Size | new_avx512 | new_sse2 | old_avx512 | old_sse2 | |------------|------------|----------|------------|----------| | 64 | 1.01 | **1.00** | 13.45 | 1.13 | | 1024 | 1.01 | **1.00** | 13.53 | 1.14 | | 65536 | 1.01 | **1.00** | 13.99 | 1.12 | | 1048576 | 1.02 | **1.00** | 13.29 | 1.12 | ### late_non_ascii | Input Size | new_avx512 | new_sse2 | old_avx512 | old_sse2 | |------------|------------|----------|------------|----------| | 64 | **1.00** | 1.01 | 13.37 | 1.13 | | 1024 | 1.10 | **1.00** | 42.42 | 1.95 | | 65536 | **1.00** | 1.06 | 42.22 | 1.73 | | 1048576 | **1.00** | 1.03 | 34.73 | 1.46 | ### pure_ascii | Input Size | new_avx512 | new_sse2 | old_avx512 | old_sse2 | |------------|------------|----------|------------|----------| | 4 | 1.03 | **1.00** | 1.75 | 1.32 | | 8 | **1.00** | 1.14 | 3.89 | 2.06 | | 16 | **1.00** | 1.04 | 1.13 | 1.62 | | 32 | 1.07 | 1.19 | 5.11 | **1.00** | | 64 | **1.00** | 1.13 | 13.32 | 1.57 | | 128 | **1.00** | 1.01 | 19.97 | 1.55 | | 256 | **1.00** | 1.02 | 27.77 | 1.61 | | 1024 | **1.00** | 1.02 | 41.34 | 1.84 | | 4096 | 1.02 | **1.00** | 45.61 | 1.98 | | 16384 | 1.01 | **1.00** | 48.67 | 2.04 | | 65536 | **1.00** | 1.03 | 43.86 | 1.77 | | 262144 | **1.00** | 1.06 | 41.44 | 1.79 | | 1048576 | 1.02 | **1.00** | 35.36 | 1.44 | </details> ## Reproduction / Test Projects Standalone validation tools: https://github.com/bonega/is-ascii-fix-validation - `bench/` - Criterion benchmarks for SSE2 vs AVX-512 comparison - `fuzz/` - Compares old/new implementations with libfuzzer Relates to: llvm/llvm-project#176906

…r=joboet Add missing mut to pin.rs docs Per my understanding, needed for mut access next line.

…=Zalathar compiletest: add implied `needs-target-std` for `codegen` mode tests unless annotated with `#![no_std]`/`#![no_core]` A `codegen` mode test (such as `codegen-llvm` test suite) will now by default have an implied `//@ needs-target-std` directive, *unless* the test explicitly has an `#![no_std]`/`#![no_core]` attribute which disables this behavior. - When a test has both `#![no_std]`/`#![no_core]` and `//@ needs-target-std`, the explicit `//@ needs-target-std` directive will cause the test to be ignored for targets that do not support std still. This is to make it easier to test out-of-tree targets / custom targets (and targets not tested in r-l/r CI) without requiring target maintainers to do a bunch of manual `//@ needs-target-std` busywork. Context: [#t-compiler/help > &rust-lang#96;compiletest&rust-lang#96; cannot find &rust-lang#96;core&rust-lang#96; library for target != host](https://rust-lang.zulipchat.com/#narrow/channel/182449-t-compiler.2Fhelp/topic/.60compiletest.60.20cannot.20find.20.60core.60.20library.20for.20target.20!.3D.20host/with/568652419) ## Implementation remarks This is an alternative version of rust-lang#150672, with some differences: - *This* PR applies this implied-`needs-target-std` behavior to all `codegen` test mode tests. - *This* PR does the synthetic directive injection in the same place as implied-`codegen-run` directives. Both are of course hacks, but at least they're together next to each other.

…aumeGomez Add a `documentation` remapping path scope for rustdoc usage This PR adds a new remapping path scope for rustdoc usage: `documentation`, instead of rustdoc abusing the other scopes for it's usage. Like remapping paths in rustdoc, this scope is unstable. (rustdoc doesn't even have yet an equivalent to [rustc `--remap-path-scope`](https://doc.rust-lang.org/nightly/rustc/remap-source-paths.html#--remap-path-scope)). I also took the opportunity to add a bit of documentation in rustdoc book.

Fix broken WASIp1 reference link ### Location (URL) https://doc.rust-lang.org/rustc/platform-support/wasm32-wasip1.html <img width="800" alt="image" src="https://github.com/user-attachments/assets/b9402b3a-db7b-405f-b4ef-d849c03ad893" /> ### Summary The WASIp1 reference link in the `wasm32-wasip1` platform documentation currently points to a path that no longer exists in the WASI repository. The WASI project recently migrated the WASI 0.1 (preview1) documentation from the `legacy/preview1` directory to the dedicated `wasi-0.1` branch (WebAssembly/WASI#855). This updates the link to point to the intended historical WASIp1 reference, which matches the documented intent of the `wasm32-wasip1` target.

@Kobzol

…obzol Update `sysinfo` version to `0.38.0` Some bugfixes and added supported for NetBSD. r? @Kobzol

Zalathar · 2026-01-26T03:36:41Z

Rollup of everything.

@bors r+ rollup=never p=5

rust-bors · 2026-01-26T03:36:44Z

📌 Commit ec48041 has been approved by Zalathar

It is now in the queue for this repository.

Zalathar · 2026-01-26T03:38:29Z

Checking the probably-flaky failure from #151664 (comment):

@bors try jobs=i686-gnu-1

Rollup of 6 pull requests try-job: i686-gnu-1

rust-bors · 2026-01-26T06:09:16Z

☀️ Try build successful (CI)
Build commit: b7d669e (b7d669eb39c5d2b94f5ea136486ee5b8e9a760b0, parent: 873d4682c7d285540b8f28bfe637006cef8918a6)

rust-bors · 2026-01-26T09:25:14Z

☀️ Test successful - CI
Approved by: Zalathar
Duration: 3h 42m 19s
Pushing 0462e8f to main...

rust-timer · 2026-01-26T09:26:58Z

📌 Perf builds for each rolled up PR:

PR#	Message	Perf Build Sha
#150705	Add missing mut to pin.rs docs	`33e78feeede8a7d57d9b910b199b088550a5ced1` (link)
#151294	compiletest: add implied `needs-target-std` for `codegen` m…	`099101ea82c952349f4130f8caea617fbdeafb1b` (link)
#151589	Add a `documentation` remapping path scope for rustdoc usage	`00c04f9fa38ce73385147dc052b66eee4afb9e2e` (link)
#151611	Improve is_ascii performance on x86_64 with explicit SSE2 i…	`34b0423a2432740ce6f2f7203896331792d3e7ce` (link)
#151639	Fix broken WASIp1 reference link	`d971337d8c863fa5561e80b0d03cb27711873f16` (link)
#151645	Update `sysinfo` version to `0.38.0`	`a04ec21aff8ec0e5e71fbace137f443da7aacaa9` (link)

previous master: fb292b75fb

In the case of a perf regression, run the following command for each PR you suspect might be the cause: @rust-timer build $SHA

github-actions · 2026-01-26T09:28:33Z

What is this?

This is an experimental post-merge analysis report that shows differences in test outcomes between the merged PR and its parent PR.

Comparing fb292b7 (parent) -> 0462e8f (this PR)

Test differences

Show 79 test diffs

Stage 0

directives::tests::implied_needs_target_std: [missing] -> pass (J2)

Stage 1

[ui] tests/ui/compile-flags/invalid/remap-path-scope.rs#foo: [missing] -> pass (J0)
[ui] tests/ui/compile-flags/invalid/remap-path-scope.rs#underscore: [missing] -> pass (J0)
[ui] tests/ui/errors/remap-path-prefix-diagnostics.rs#only-doc-in-deps: [missing] -> pass (J0)
[ui] tests/ui/errors/remap-path-prefix-diagnostics.rs#with-doc-in-deps: [missing] -> pass (J0)
[ui] tests/ui/errors/remap-path-prefix-macro.rs#only-doc-in-deps: [missing] -> pass (J0)
[ui] tests/ui/errors/remap-path-prefix-macro.rs#with-doc-in-deps: [missing] -> pass (J0)
[ui] tests/ui/feature-gates/remap-path-scope-documentation.rs: [missing] -> pass (J0)

Stage 2

[ui] tests/ui/compile-flags/invalid/remap-path-scope.rs#foo: [missing] -> pass (J1)
[ui] tests/ui/compile-flags/invalid/remap-path-scope.rs#underscore: [missing] -> pass (J1)
[ui] tests/ui/errors/remap-path-prefix-diagnostics.rs#only-doc-in-deps: [missing] -> pass (J1)
[ui] tests/ui/errors/remap-path-prefix-diagnostics.rs#with-doc-in-deps: [missing] -> pass (J1)
[ui] tests/ui/errors/remap-path-prefix-macro.rs#only-doc-in-deps: [missing] -> pass (J1)
[ui] tests/ui/errors/remap-path-prefix-macro.rs#with-doc-in-deps: [missing] -> pass (J1)
[ui] tests/ui/feature-gates/remap-path-scope-documentation.rs: [missing] -> pass (J1)

Additionally, 64 doctest diffs were found. These are ignored, as they are noisy.

Job group index

Test dashboard

Run

cargo run --manifest-path src/ci/citool/Cargo.toml -- \
    test-dashboard 0462e8f7e51f20692b02d68efee68bb28a6f4457 --output-dir test-dashboard

And then open test-dashboard/index.html in your browser to see an overview of all executed tests.

Job duration changes

dist-aarch64-apple: 8394.7s -> 5965.4s (-28.9%)
pr-check-1: 1685.2s -> 2018.9s (+19.8%)
i686-gnu-2: 5233.2s -> 6164.0s (+17.8%)
aarch64-apple: 11260.7s -> 12925.4s (+14.8%)
x86_64-rust-for-linux: 2723.3s -> 3125.0s (+14.8%)
x86_64-gnu-tools: 3352.2s -> 3846.1s (+14.7%)
x86_64-gnu-miri: 4409.3s -> 5026.3s (+14.0%)
i686-gnu-nopt-1: 7326.3s -> 8298.0s (+13.3%)
armhf-gnu: 4851.2s -> 5424.5s (+11.8%)
i686-gnu-1: 7595.4s -> 8460.5s (+11.4%)

How to interpret the job duration changes?

Job durations can vary a lot, based on the actual runner instance
that executed the job, system noise, invalidated caches, etc. The table above is provided
mostly for t-infra members, for simpler debugging of potential CI slow-downs.

rust-timer · 2026-01-26T10:06:28Z

Finished benchmarking commit (0462e8f): comparison URL.

Overall result: no relevant changes - no action needed

@rustbot label: -perf-regression

Instruction count

This benchmark run did not return any relevant results for this metric.

Max RSS (memory usage)

Results (primary 2.3%, secondary -0.9%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	2.3%	[2.3%, 2.3%]	1
Regressions ❌ (secondary)	7.8%	[7.8%, 7.8%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-5.3%	[-5.4%, -5.1%]	2
All ❌✅ (primary)	2.3%	[2.3%, 2.3%]	1

Cycles

Results (primary -1.0%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-1.0%	[-1.4%, -0.6%]	2
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-1.0%	[-1.4%, -0.6%]	2

Binary size

Results (primary 0.1%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	0.1%	[0.1%, 0.1%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.1%	[0.1%, 0.1%]	1

Bootstrap: 475.284s -> 473.061s (-0.47%)
Artifact size: 383.64 MiB -> 383.58 MiB (-0.02%)

justanotheranonymoususer and others added 18 commits January 22, 2026 14:00

Add missing mut to pin.rs docs

672828e

Per my understanding, needed for mut access next line.

Add test for invalid --remap-path-scope arguments

ee6dd56

Add the remapping path documentation scope for rustdoc usage

91e3e2a

Make rustdoc use the documentation remapping scope and cleanups

fbab2c0

Make sure the documentation scope doesn't imply other scopes

3d6a5b5

Add documentation for --remap-path-prefix and doc scope in rustdoc

dd84a4f

Fix is_ascii performance on x86_64 with explicit SSE2 intrinsics

a72f68e

Use explicit SSE2 intrinsics to avoid LLVM's broken AVX-512 auto-vectorization which generates ~31 kshiftrd instructions. Performance - AVX-512: 34-48x faster - SSE2: 1.5-2x faster Improves on earlier pr

Fix broken WASIp1 reference link

9e80b1b

Remove x86_64 assembly test for is_ascii

cbcd869

The SSE2 helper function is not inlined across crate boundaries, so we cannot verify the codegen in an assembly test. The fix is still verified by the absence of performance regression.

Update sysinfo version to 0.38.0

36fb9f0

Mark is_ascii_sse2 as #[inline]

dbc870a

Rollup merge of rust-lang#150705 - justanotheranonymoususer:patch-1, …

ef849a2

…r=joboet Add missing mut to pin.rs docs Per my understanding, needed for mut access next line.

Rollup merge of rust-lang#151645 - GuillaumeGomez:update-sysinfo, r=K…

ec48041

…obzol Update `sysinfo` version to `0.38.0` Some bugfixes and added supported for NetBSD. r? @Kobzol

rust-bors bot added the rollup A PR which is a rollup label Jan 26, 2026

rust-bors bot added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Jan 26, 2026

rust-bors bot pushed a commit that referenced this pull request Jan 26, 2026

Auto merge of #151667 - Zalathar:rollup-OzG0S5m, r=<try>

b7d669e

Rollup of 6 pull requests try-job: i686-gnu-1

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Rollup of 4 pull requests #151664

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rust-bors bot added merged-by-bors This PR was explicitly merged by bors. and removed S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. labels Jan 26, 2026

rust-bors bot merged commit 0462e8f into rust-lang:main Jan 26, 2026
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rustbot added this to the 1.95.0 milestone Jan 26, 2026

Zalathar deleted the rollup-OzG0S5m branch January 26, 2026 09:26

rust-bors bot mentioned this pull request Jan 26, 2026

compiletest/codegen-llvm: automatically add needs-target-std if needed #150672

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Rollup of 2 pull requests #151674

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Remove Deref<Target = TyCtxt> from QueryCtxt #151626

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Overall result: no relevant changes - no action needed

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