Experiment linking with Wild

[mati865]

Due to master branch migration, I cannot reopen #146421, so I'm moving to a new PR. Hopefully this sporadic perf testing is not viewed as disrupting or harmful to the project, otherwise let me know.

[mati865]

@bors try @rust-timer queue

[Urgau]

Don't worry about using our CI capacity. We explicitly allow "wasting our ressources":

Rust has plenty of CI capacity, and you should never have to worry about wasting computational resources each time you push a change. It is also perfectly fine (and even encouraged!) to use the CI to test your changes if it can help your productivity. In particular, we don’t recommend running the full ./x test suite locally, since it takes a very long time to execute.

[rust-bors]

💔 Test for fbf0e6a failed: CI. Failed jobs:

• try - dist-x86_64-linux (web logs, enhanced plaintext logs)

[mati865]

@bors try

[rust-log-analyzer]

The job tidy failed! Check out the build log: (web) (plain enhanced) (plain)

Click to see the possible cause of the failure (guessed by this bot)

fmt: checked 6635 files
tidy check
tidy [rustdoc_json (src)]: `rustdoc-json-types` modified, checking format version
tidy: Skipping binary file check, read-only filesystem
tidy [style (compiler)]: /checkout/compiler/rustc_target/src/spec/mod.rs:131: TODO is used for tasks that should be done before merging a PR; If you want to leave a message in the codebase use FIXME
tidy [style (compiler)]: FAIL
removing old virtual environment
creating virtual environment at '/checkout/obj/build/venv' using 'python3.10' and 'venv'
creating virtual environment at '/checkout/obj/build/venv' using 'python3.10' and 'virtualenv'
Requirement already satisfied: pip in ./build/venv/lib/python3.10/site-packages (25.3)
linting python files
---
linting javascript files and applying suggestions
Running eslint on rustdoc JS files
info: ES-Check: there were no ES version matching errors!  🎉
typechecking javascript files
tidy: The following check failed: style (compiler)
Command `/checkout/obj/build/x86_64-unknown-linux-gnu/stage1-tools-bin/rust-tidy /checkout /checkout/obj/build/x86_64-unknown-linux-gnu/stage0/bin/cargo /checkout/obj/build 4 /node/bin/yarn --extra-checks=py,cpp,js,spellcheck` failed with exit code 1
Created at: src/bootstrap/src/core/build_steps/tool.rs:1713:23
Executed at: src/bootstrap/src/core/build_steps/test.rs:1357:29

Command has failed. Rerun with -v to see more details.
Bootstrap failed while executing `test src/tools/tidy tidyselftest --extra-checks=py,cpp,js,spellcheck`
Build completed unsuccessfully in 0:02:55
  local time: Mon Jan 12 23:18:46 UTC 2026
  network time: Mon, 12 Jan 2026 23:18:46 GMT
##[error]Process completed with exit code 1.

[rust-bors]

☀️ Try build successful (CI)
Build commit: 289623b (289623b501cf708780d96485b05c4ccac7857d00, parent: aefa10405d7b67b3780027484cb02c85d3a3bf36)

[rust-timer]

Finished benchmarking commit (289623b): comparison URL.

Overall result: ✅ improvements - no action needed

Benchmarking this pull request means it may be perf-sensitive – we'll automatically label it not fit for rolling up. You can override this, but we strongly advise not to, due to possible changes in compiler perf.

@bors rollup=never
@rustbot label: -S-waiting-on-perf -perf-regression

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
Regressions ❌ (secondary)	0.0%	[0.0%, 0.0%]	1
Improvements ✅ (primary)	-3.9%	[-13.7%, -0.3%]	25
Improvements ✅ (secondary)	-2.6%	[-12.9%, -0.0%]	71
All ❌✅ (primary)	-3.9%	[-13.7%, -0.3%]	25

Max RSS (memory usage)

Results (primary -5.0%, 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)	4.1%	[4.1%, 4.1%]	1
Regressions ❌ (secondary)	1.8%	[0.7%, 3.3%]	8
Improvements ✅ (primary)	-9.6%	[-14.0%, -5.3%]	2
Improvements ✅ (secondary)	-3.7%	[-4.9%, -1.8%]	8
All ❌✅ (primary)	-5.0%	[-14.0%, 4.1%]	3

Cycles

Results (primary -6.2%, secondary -5.7%)

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%	[4.5%, 4.5%]	1
Improvements ✅ (primary)	-6.2%	[-11.9%, -2.6%]	14
Improvements ✅ (secondary)	-6.0%	[-12.2%, -2.1%]	41
All ❌✅ (primary)	-6.2%	[-11.9%, -2.6%]	14

Binary size

Results (primary -1.0%, 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)	0.9%	[0.9%, 1.0%]	4
Regressions ❌ (secondary)	3.0%	[0.0%, 3.9%]	5
Improvements ✅ (primary)	-1.3%	[-2.4%, -0.4%]	28
Improvements ✅ (secondary)	-2.1%	[-4.1%, -0.0%]	48
All ❌✅ (primary)	-1.0%	[-2.4%, 1.0%]	32

Bootstrap: 474.371s -> 521.958s (10.03%)
Artifact size: 391.41 MiB -> 393.44 MiB (0.52%)