Rollup of 5 pull requests by JonathanBrouwer · Pull Request #152361 · rust-lang/rust

JonathanBrouwer · 2026-02-08T20:06:31Z

Successful merges:

add test for codegen of SIMD vector from array repeat #151869 (add test for codegen of SIMD vector from array repeat)
bootstrap: always propagate CARGO_TARGET_{host}_LINKER #152077 (bootstrap: always propagate CARGO_TARGET_{host}_LINKER)
Reword the caveats on array::map #126100 (Reword the caveats on array::map)
Stop having two different alignment constants #152275 (Stop having two different alignment constants)
Remove more adhoc groups that correspond to teams #152325 (Remove more adhoc groups that correspond to teams)

Thanks to 107634 and some improvements in LLVM (particularly `dead_on_unwind`), the method actually optimizes reasonably well now. So focus the discussion on the fundamental ordering differences where the optimizer might never be able to fix it because of the different behaviour, and encouraging `Iterator::map` where an array wasn't actually ever needed.

We were already setting `CARGO_TARGET_{target}_LINKER` when there is a setting in `bootstrap.toml`, and when the host and target are the same, this is also used for build scripts and proc-macros. However, the host value wasn't set when building for any other target, and Cargo would see that as a fingerprint change for those build artifacts, rebuilding them. If we always set the `CARGO_TARGET_{host}_LINKER`, then those build scripts will keep a consistent Cargo fingerprint, so they'll remain cached no matter how we're alternating targets.

* Stop having two different alignment constants * Update library/core/src/alloc/global.rs

@programmerjake

…rk-Simulacrum add test for codegen of SIMD vector from array repeat fixes rust-lang#97804 It appears that this issue was fixed silently in LLVM 19. The original codegen was terrible, but starting at LLVM 19 `opt` is able to generate good code. https://llvm.godbolt.org/z/5vq8scP6q cc @programmerjake

…ark-Simulacrum bootstrap: always propagate `CARGO_TARGET_{host}_LINKER` We were already setting `CARGO_TARGET_{target}_LINKER` when there is a setting in `bootstrap.toml`, and when the host and target are the same, this is also used for build scripts and proc-macros. However, the host value wasn't set when building for any other target, and Cargo would see that as a fingerprint change for those build artifacts, rebuilding them. If we always set the `CARGO_TARGET_{host}_LINKER`, then those build scripts will keep a consistent Cargo fingerprint, so they'll remain cached no matter how we're alternating targets.

…lacrum Reword the caveats on `array::map` Thanks to rust-lang#107634 and some improvements in LLVM (particularly [`dead_on_unwind`](https://llvm.org/docs/LangRef.html#parameter-attributes)), the method actually optimizes reasonably well now. So focus the discussion on the fundamental ordering differences where the optimizer might never be able to fix it because of the different behaviour, and keep encouraging `Iterator::map` where an array wasn't actually ever needed.

…Mark-Simulacrum Stop having two different alignment constants Now that there's a `<T as SizedTypeProperties>::ALIGNMENT` constant, `Alignment::of` can use that instead of an inline constant, like how `Layout::new` uses the constant from `SizedTypeProperties`.

…-Simulacrum Remove more adhoc groups that correspond to teams Following in the footsteps of rust-lang#152310. - [types](https://github.com/rust-lang/team/blob/main/teams/types.toml) team - removed Niko and lqd from team rotation in triagebot - [project-const-traits](https://github.com/rust-lang/team/blob/main/teams/project-const-traits.toml) - no changes needed, whole team was already on rotation - [project-stable-mir](https://github.com/rust-lang/team/blob/main/teams/project-stable-mir.toml) - no changes needed, whole team was already on rotation - [project-exploit-mitigations](https://github.com/rust-lang/team/blob/main/teams/project-exploit-mitigations.toml) - removed 1c3t3a from team rotation in triagebot (TODO - it didn't work yet, need to fix triagebot to allow running commands on top of people that are only in project/working groups)

JonathanBrouwer · 2026-02-08T20:06:38Z

@bors r+ rollup=never p=5

rust-bors · 2026-02-08T20:06:41Z

📌 Commit b0c9c4b has been approved by JonathanBrouwer

It is now in the queue for this repository.

rust-bors · 2026-02-09T01:12:33Z

☀️ Test successful - CI
Approved by: JonathanBrouwer
Duration: 3h 30m 1s
Pushing 1c316d3 to main...

rust-timer · 2026-02-09T01:13:58Z

📌 Perf builds for each rolled up PR:

PR#	Message	Perf Build Sha
#126100	Reword the caveats on `array::map`	`fb2577d0b0bea5c317fa09dcc5e7bcca0dcb4273` (link)
#151869	add test for codegen of SIMD vector from array repeat	`195cfd5b04704a404adf93cced87a78b5179bda4` (link)
#152077	bootstrap: always propagate `CARGO_TARGET_{host}_LINKER`	`5e61681a855c56ae9572fc31ce7040fea38df6e1` (link)
#152275	Stop having two different alignment constants	`dd2ee24a3d8bc434e0398c09adf2630100d94d36` (link)
#152325	Remove more adhoc groups that correspond to teams	`19fc9fdc841f8c9715eb92b3e2ce2453cbeef529` (link)

previous master: 6efa357bff

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 · 2026-02-09T01:15:02Z

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 6efa357 (parent) -> 1c316d3 (this PR)

Test differences

Show 86 test diffs

Stage 1

[codegen] tests/codegen-llvm/simd/array-repeat.rs#AARCH64: [missing] -> pass (J0)
[codegen] tests/codegen-llvm/simd/array-repeat.rs#RISCV: [missing] -> pass (J0)
[codegen] tests/codegen-llvm/simd/array-repeat.rs#S390X: [missing] -> pass (J0)
[codegen] tests/codegen-llvm/simd/array-repeat.rs#X86: [missing] -> pass (J0)

Stage 2

[codegen] tests/codegen-llvm/simd/array-repeat.rs#AARCH64: [missing] -> pass (J1)
[codegen] tests/codegen-llvm/simd/array-repeat.rs#RISCV: [missing] -> pass (J1)
[codegen] tests/codegen-llvm/simd/array-repeat.rs#S390X: [missing] -> pass (J1)
[codegen] tests/codegen-llvm/simd/array-repeat.rs#X86: [missing] -> pass (J1)

Additionally, 78 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 1c316d34610a3cd31831d2ae8e5dd454f26de430 --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-x86_64-apple: 2h 14m -> 1h 41m (-24.7%)
aarch64-apple: 2h 31m -> 2h 52m (+14.0%)
dist-sparcv9-solaris: 1h 39m -> 1h 31m (-7.8%)
dist-aarch64-msvc: 1h 43m -> 1h 35m (-7.2%)
x86_64-gnu-stable: 2h 21m -> 2h 11m (-7.0%)
x86_64-gnu-gcc: 1h 3m -> 59m 17s (-6.9%)
aarch64-msvc-1: 2h 9m -> 2h (-6.7%)
aarch64-gnu-debug: 1h 11m -> 1h 6m (-6.7%)
dist-powerpc-linux: 1h 22m -> 1h 28m (+6.3%)
dist-x86_64-llvm-mingw: 1h 55m -> 2h 2m (+6.3%)

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 · 2026-02-09T01:54:30Z

Finished benchmarking commit (1c316d3): 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 2.8%, secondary 1.7%)

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

	mean	range	count
Regressions ❌ (primary)	2.8%	[1.5%, 4.1%]	2
Regressions ❌ (secondary)	5.1%	[4.5%, 5.6%]	2
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-5.0%	[-5.0%, -5.0%]	1
All ❌✅ (primary)	2.8%	[1.5%, 4.1%]	2

Cycles

Results (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)	-	-	0
Regressions ❌ (secondary)	4.9%	[3.0%, 6.8%]	2
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-3.1%	[-3.9%, -2.3%]	2
All ❌✅ (primary)	-	-	0

Binary size

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

Bootstrap: 477.097s -> 475.432s (-0.35%)
Artifact size: 397.86 MiB -> 397.82 MiB (-0.01%)

scottmcm and others added 13 commits January 17, 2026 17:14

add test for simd from array repeat codegen

ef7a780

Remove types adhoc group

6b1ed21

Remove project-const-traits adhoc group

c19c780

Remove project-stable-mir adhoc group

5e33ea7

Remove project-exploit-mitigations adhoc group

f460320

Stop having two different alignment constants

4a979d5

* Stop having two different alignment constants * Update library/core/src/alloc/global.rs

rust-bors bot added the rollup A PR which is a rollup label Feb 8, 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 Feb 8, 2026

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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 Feb 9, 2026

rust-bors bot merged commit 1c316d3 into rust-lang:main Feb 9, 2026
12 checks passed

rustbot added this to the 1.95.0 milestone Feb 9, 2026

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Rollup of 5 pull requests#152361

Rollup of 5 pull requests#152361
rust-bors[bot] merged 13 commits intorust-lang:mainfrom
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Overall result: no relevant changes - no action needed

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