Rollup of 4 pull requests #151749

JonathanBrouwer · 2026-01-27T16:00:55Z

Successful merges:

std: move time implementations to sys #151161 (std: move time implementations to sys)
more proc_macro bridge cleanups #151694 (more proc_macro bridge cleanups)
stdarch subtree update #151711 (stdarch subtree update)
Don't try to evaluate const blocks during constant promotion #150557 (Don't try to evaluate const blocks during constant promotion)

This allows the `types` macro to easily implement `From<Simd<T, N>>` and `Into<Simd<T, N>>`

…oid-unsafe-tests Use a generic type to implement SIMD types in `core_arch::simd` and avoid `unsafe fn` in more tests

For other targets we don't have such instances. We specifically decided agains implementing arithmetic operators on these low-level vector types

The inline(always) attribute is now applied to the call site when a function has target features enabled so that it can determine that the call is safe to inline.

thread, grid, and block dim/idx can only return non-negative values

remove `impl Neg` on s390x/powerpc vector types

Mark the neon intrinsics as inline(always).

use `simd_extract_dyn` for `extract`

Because `qemu` does not support these (yet), I haven't added any runtime tests

s390x: add `nnp-assist` intrinsics

test `vmulh_lane_f16` in intrinsic test

Stabilize `__jcvt`

This updates the rust-version file to 873d468.

Pull recent changes from https://github.com/rust-lang/rust via Josh. Upstream ref: rust-lang/rust@873d468 Filtered ref: rust-lang/stdarch@003d326 Upstream diff: rust-lang/rust@4862272...873d468 This merge was created using https://github.com/rust-lang/josh-sync.

Rustc pull update

use `simd_splat`

JonathanBrouwer · 2026-01-27T16:01:07Z

@bors r+ rollup=never p=5

rust-bors · 2026-01-27T16:01:17Z

📌 Commit 53fb684 has been approved by JonathanBrouwer

It is now in the queue for this repository.

rust-bors · 2026-01-27T21:04:35Z

☀️ Test successful - CI
Approved by: JonathanBrouwer
Duration: 3h 23m 58s
Pushing e96bb7e to main...

rust-timer · 2026-01-27T21:05:46Z

📌 Perf builds for each rolled up PR:

PR#	Message	Perf Build Sha
#150557	Don't try to evaluate const blocks during constant promotion	`8d0fe88ffa814dcdb29368a0ab6a8e9aee1ba15d` (link)
#151161	std: move time implementations to `sys`	`cd13f942328e436d0704cafd97e522acd93cf333` (link)
#151694	more `proc_macro` bridge cleanups	`ce5409c2ca9d7b95a1aa646716269c6be06f5881` (link)
#151711	stdarch subtree update	`192c8ae6f9513ce9bb7943a5a61c39cd7935d06e` (link)

previous master: 94a0cd15f5

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 · 2026-01-27T21:07:15Z

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 94a0cd1 (parent) -> e96bb7e (this PR)

Test differences

Show 6 test diffs

Stage 1

[ui] tests/ui/inline-const/dont-eval-const-block-during-promotion.rs#fail: [missing] -> pass (J1)
[ui] tests/ui/inline-const/dont-eval-const-block-during-promotion.rs#pass: [missing] -> pass (J1)

Stage 2

[ui] tests/ui/inline-const/dont-eval-const-block-during-promotion.rs#fail: [missing] -> pass (J0)
[ui] tests/ui/inline-const/dont-eval-const-block-during-promotion.rs#pass: [missing] -> pass (J0)

Additionally, 2 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 e96bb7e44fbcc23c1e6009e8d0ee8ab208668fb4 --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: 6979.8s -> 9519.1s (+36.4%)
dist-aarch64-linux: 9171.1s -> 6376.7s (-30.5%)
dist-loongarch64-musl: 7538.5s -> 5658.7s (-24.9%)
dist-loongarch64-linux: 7349.9s -> 5641.3s (-23.2%)
dist-apple-various: 3681.0s -> 4322.4s (+17.4%)
dist-x86_64-apple: 7745.2s -> 8831.4s (+14.0%)
dist-aarch64-llvm-mingw: 5237.7s -> 5804.6s (+10.8%)
arm-android: 5325.6s -> 5871.7s (+10.3%)
dist-armv7-linux: 5195.1s -> 5687.0s (+9.5%)
dist-various-2: 2092.2s -> 2281.2s (+9.0%)

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 · 2026-01-27T21:45:40Z

Finished benchmarking commit (e96bb7e): comparison URL.

Overall result: ❌✅ regressions and improvements - please read the text below

Our benchmarks found a performance regression caused by this PR.
This might be an actual regression, but it can also be just noise.

Next Steps:

If the regression was expected or you think it can be justified,
please write a comment with sufficient written justification, and add
@rustbot label: +perf-regression-triaged to it, to mark the regression as triaged.
If you think that you know of a way to resolve the regression, try to create
a new PR with a fix for the regression.
If you do not understand the regression or you think that it is just noise,
you can ask the @rust-lang/wg-compiler-performance working group for help (members of this group
were already notified of this PR).

@rustbot label: +perf-regression
cc @rust-lang/wg-compiler-performance

Instruction count

Our most reliable metric. Used to determine the overall result above. However, even this metric can be noisy.

	mean	range	count
Regressions ❌ (primary)	0.4%	[0.4%, 0.4%]	1
Regressions ❌ (secondary)	0.1%	[0.0%, 0.1%]	3
Improvements ✅ (primary)	-0.2%	[-0.4%, -0.1%]	22
Improvements ✅ (secondary)	-0.5%	[-1.9%, -0.1%]	53
All ❌✅ (primary)	-0.2%	[-0.4%, 0.4%]	23

Max RSS (memory usage)

Results (primary 0.5%, secondary 1.8%)

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

	mean	range	count
Regressions ❌ (primary)	2.1%	[1.0%, 3.9%]	7
Regressions ❌ (secondary)	5.1%	[4.4%, 5.6%]	6
Improvements ✅ (primary)	-2.2%	[-4.8%, -0.8%]	4
Improvements ✅ (secondary)	-2.3%	[-3.2%, -1.6%]	5
All ❌✅ (primary)	0.5%	[-4.8%, 3.9%]	11

Cycles

Results (secondary -1.6%)

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)	4.5%	[4.3%, 4.7%]	2
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-3.6%	[-7.9%, -2.0%]	6
All ❌✅ (primary)	-	-	0

Binary size

Results (primary 0.2%)

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

	mean	range	count
Regressions ❌ (primary)	0.2%	[0.1%, 0.5%]	5
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.2%	[0.1%, 0.5%]	5

Bootstrap: 473.018s -> 470.891s (-0.45%)
Artifact size: 385.68 MiB -> 383.44 MiB (-0.58%)

nnethercote · 2026-01-28T03:19:24Z

We have an unexpected perf improvement, yay. Maybe #151694?

@rust-timer build ce5409c

rust-timer · 2026-01-28T04:15:10Z

Finished benchmarking commit (ce5409c): comparison URL.

Overall result: ❌ regressions - no action needed

Instruction count

Our most reliable metric. Used to determine the overall result above. However, even this metric can be noisy.

	mean	range	count
Regressions ❌ (primary)	0.4%	[0.4%, 0.4%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.4%	[0.4%, 0.4%]	1

Max RSS (memory usage)

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

Cycles

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

Binary size

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

Bootstrap: 473.018s -> 473.507s (0.10%)
Artifact size: 385.68 MiB -> 385.70 MiB (0.00%)

nnethercote · 2026-01-28T05:44:32Z

@rust-timer build 8d0fe88

rust-timer · 2026-01-28T06:25:11Z

Finished benchmarking commit (8d0fe88): comparison URL.

Overall result: no relevant changes - no action needed

Instruction count

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

Max RSS (memory usage)

Results (secondary -5.1%)

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)	-	-	0
Improvements ✅ (secondary)	-5.1%	[-5.1%, -5.1%]	1
All ❌✅ (primary)	-	-	0

Cycles

Results (primary -2.2%, secondary -2.9%)

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)	-	-	0
Improvements ✅ (primary)	-2.2%	[-2.2%, -2.2%]	1
Improvements ✅ (secondary)	-2.9%	[-2.9%, -2.9%]	1
All ❌✅ (primary)	-2.2%	[-2.2%, -2.2%]	1

Binary size

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

Bootstrap: 473.018s -> 472.846s (-0.04%)
Artifact size: 385.68 MiB -> 385.70 MiB (0.00%)

ZuseZ4 and others added 30 commits December 9, 2025 10:52

thread, grid, and block dim/idx can only return non-negative values

79b30d6

Use a generic type to implement SIMD types in core_arch::simd

69c7a7e

This allows the `types` macro to easily implement `From<Simd<T, N>>` and `Into<Simd<T, N>>`

x86: avoid using transmute in some tests

dab5532

arm_shared: avoid using transmute and unsafe fn in tests

68701ff

Merge pull request rust-lang#1987 from eduardosm/generic-simd-type-av…

f9e6d4b

…oid-unsafe-tests Use a generic type to implement SIMD types in `core_arch::simd` and avoid `unsafe fn` in more tests

remove impl Neg on s390x/powerpc vector types

d0204a3

For other targets we don't have such instances. We specifically decided agains implementing arithmetic operators on these low-level vector types

Mark the neon intrinsics as inline(always).

78952f6

The inline(always) attribute is now applied to the call site when a function has target features enabled so that it can determine that the call is safe to inline.

stabilize __jscvt

5bf9ca7

Merge pull request rust-lang#1973 from ZuseZ4/u32-threadidx

aaf31e7

thread, grid, and block dim/idx can only return non-negative values

Merge pull request rust-lang#1992 from folkertdev/remove-impl-neg

0d802f5

remove `impl Neg` on s390x/powerpc vector types

Merge pull request rust-lang#1974 from JamieCunliffe/inline-always-neon

d251a38

Mark the neon intrinsics as inline(always).

test vmulh_lane_f16 in intrinsic test

bf7c1c2

use simd_extract_dyn for extract

b1ef655

Merge pull request rust-lang#1997 from folkertdev/use-extract-dyn

5829f21

use `simd_extract_dyn` for `extract`

s390x: add nnp-assist intrinsics

cf08a11

Because `qemu` does not support these (yet), I haven't added any runtime tests

Merge pull request rust-lang#1996 from folkertdev/s390x-nnp-assist

84fc953

s390x: add `nnp-assist` intrinsics

Merge pull request rust-lang#1998 from folkertdev/test-vmulh_lane_f16

5ec32b5

test `vmulh_lane_f16` in intrinsic test

Merge pull request rust-lang#1993 from folkertdev/stabilize-jscvt

464b309

Stabilize `__jcvt`

Prepare for merging from rust-lang/rust

a4f92e5

This updates the rust-version file to 873d468.

use simd_splat

246399c

Merge pull request rust-lang#2002 from rust-lang/rustc-pull

a45071b

Rustc pull update

move Types from with_api! to Server

bf1c3f6

inline Writer and Reader type aliases

5fef797

flatten the api_tags module

f8d05b6

introduce MarkedX type aliases

d5328c5

remove some unneeded impls

356107e

merge Mark and Unmark traits

6e7a87c

use simd_splat for the set1 functions

0ef4c3a

Merge pull request rust-lang#2003 from folkertdev/use-simd-splat

f648ba2

use `simd_splat`

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 27, 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 Jan 27, 2026

rust-bors bot merged commit e96bb7e into rust-lang:main Jan 27, 2026
12 checks passed

rustbot added this to the 1.95.0 milestone Jan 27, 2026

rust-bors bot mentioned this pull request Jan 27, 2026

reduce the amount of panics in {TokenStream, Literal}::from_str calls #147859

Open

rustbot added the perf-regression Performance regression. label Jan 27, 2026

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Rollup of 4 pull requests #151749

Rollup of 4 pull requests #151749

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JonathanBrouwer commented Jan 27, 2026

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Test differences

Stage 1

Stage 2

Job duration changes

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rust-timer commented Jan 27, 2026

Overall result: ❌✅ regressions and improvements - please read the text below

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nnethercote commented Jan 28, 2026

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rust-timer commented Jan 28, 2026

Overall result: ❌ regressions - no action needed

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Overall result: no relevant changes - no action needed

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