[perf] tiny fulfillment loop

[lcnr]

let's see perrrrrf

r? ghost

[lcnr]

@bors try @rust-timer queue

[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 7070 files
tidy check
tidy [rustdoc_json (src)]: `rustdoc-json-types` modified, checking format version
tidy: Skipping binary file check, read-only filesystem
tidy [alphabetical (compiler)]: /checkout/compiler/rustc_trait_selection/src/lib.rs:22: line not in alphabetical order (tip: use --bless to sort this list)
tidy [alphabetical (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 (26.1.2)
Collecting pip
---
typechecking javascript files
tidy: The following check failed: alphabetical (compiler)
Bootstrap failed while executing `test src/tools/tidy tidyselftest --extra-checks=py,cpp,js,spellcheck`
Currently active steps:
test::Tidy {  } at src/bootstrap/src/core/build_steps/test.rs:1606
Command `/checkout/obj/build/x86_64-unknown-linux-gnu/stage1-tools-bin/rust-tidy --root-path=/checkout --cargo-path=/checkout/obj/build/x86_64-unknown-linux-gnu/stage0/bin/cargo --output-dir=/checkout/obj/build --concurrency=4 --npm-path=/node/bin/yarn --ci=true --extra-checks=py,cpp,js,spellcheck` failed with exit code 1
Created at: src/bootstrap/src/core/build_steps/tool.rs:1627:23
Executed at: src/bootstrap/src/core/build_steps/test.rs:1684:29

Command has failed. Rerun with -v to see more details.
Build completed unsuccessfully in 0:02:42
  local time: Fri Jul 31 18:34:50 UTC 2026
  network time: Fri, 31 Jul 2026 18:34:50 GMT
##[error]Process completed with exit code 1.
##[group]Run echo "disk usage:"

[rust-bors]

☀️ Try build successful (CI)
Build commit: c1c58e0 (c1c58e0bfa5a50db36ef7bce9dde6fbfc732610d)
Base parent: 64af19d (64af19d44c63587455c76f484ce76261a9971e96)

[rust-timer]

Finished benchmarking commit (c1c58e0): comparison URL.

Overall result: ✅ improvements - no action needed

Benchmarking means the PR may be perf-sensitive. It's automatically marked not fit for rolling up. Overriding is possible but disadvised: it risks changing compiler perf.

@bors rollup=never rustc-perf
@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
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-1.7%	[-3.5%, -0.5%]	8
All ❌✅ (primary)	-	-	0

Max RSS (memory usage)

Results (primary 0.5%, 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)	3.7%	[3.7%, 3.7%]	1
Regressions ❌ (secondary)	1.6%	[0.4%, 3.9%]	8
Improvements ✅ (primary)	-2.7%	[-2.7%, -2.7%]	1
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.5%	[-2.7%, 3.7%]	2

Cycles

Results (primary 0.9%, 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)	1.0%	[0.5%, 2.3%]	10
Regressions ❌ (secondary)	0.9%	[0.4%, 2.5%]	8
Improvements ✅ (primary)	-0.5%	[-0.5%, -0.5%]	1
Improvements ✅ (secondary)	-2.7%	[-4.8%, -0.6%]	8
All ❌✅ (primary)	0.9%	[-0.5%, 2.3%]	11

Binary size

Results (primary -0.1%, secondary -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
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-0.1%	[-0.2%, -0.0%]	74
Improvements ✅ (secondary)	-0.1%	[-0.1%, -0.0%]	45
All ❌✅ (primary)	-0.1%	[-0.2%, -0.0%]	74

Bootstrap: 492.106s -> 493.116s (0.21%)
Artifact size: 390.46 MiB -> 390.33 MiB (-0.03%)

[rust-bors]

☔ The latest upstream changes (presumably #160479) made this pull request unmergeable. Please resolve the merge conflicts by rebasing.