Remove boxes from ast list elements by camsteffen · Pull Request #146221 · rust-lang/rust

camsteffen · 2025-09-05T01:13:50Z

Less indirection should be better perf.

rustbot · 2025-09-05T01:13:55Z

rustbot has assigned @spastorino.
They will have a look at your PR within the next two weeks and either review your PR or reassign to another reviewer.

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rustbot · 2025-09-05T01:13:57Z

Some changes occurred in src/tools/clippy

cc @rust-lang/clippy

Some changes occurred in src/tools/rustfmt

cc @rust-lang/rustfmt

Some changes occurred in compiler/rustc_builtin_macros/src/autodiff.rs

cc @ZuseZ4

petrochenkov · 2025-09-05T12:01:50Z

Indirection is removed, but expansion may now do more work to box the stuff and then unbox it again.
@bors2 try @rust-timer queue

Remove boxes from ast list elements

rust-bors · 2025-09-05T14:22:01Z

☀️ Try build successful (CI)
Build commit: cd2fe74 (cd2fe744675bd21a03fe74405a44184f1dbf682e, parent: ad85bc524b1ad696e42061ad8338d382dffbdbe5)

rust-timer · 2025-09-05T16:13:40Z

Finished benchmarking commit (cd2fe74): comparison URL.

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

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.

Next Steps: If you can justify the regressions found in this try perf run, please do so in sufficient writing along with @rustbot label: +perf-regression-triaged. If not, please fix the regressions and do another perf run. If its results are neutral or positive, the label will be automatically removed.

@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)	0.2%	[0.1%, 0.4%]	12
Improvements ✅ (primary)	-0.2%	[-0.2%, -0.1%]	4
Improvements ✅ (secondary)	-0.3%	[-0.4%, -0.1%]	8
All ❌✅ (primary)	-0.2%	[-0.2%, -0.1%]	4

Max RSS (memory usage)

Results (primary -0.6%, 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)	-0.6%	[-0.6%, -0.6%]	1
Improvements ✅ (secondary)	-2.9%	[-3.2%, -2.6%]	3
All ❌✅ (primary)	-0.6%	[-0.6%, -0.6%]	1

Cycles

Results (primary 1.6%, secondary 2.6%)

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

	mean	range	count
Regressions ❌ (primary)	1.6%	[1.6%, 1.6%]	1
Regressions ❌ (secondary)	2.6%	[2.2%, 3.0%]	4
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	1.6%	[1.6%, 1.6%]	1

Binary size

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

Bootstrap: 467.829s -> 467.149s (-0.15%)
Artifact size: 390.58 MiB -> 390.60 MiB (0.00%)

camsteffen · 2025-09-05T16:39:26Z

Seems neutral/mixed with a bit of max RSS improvements?

camsteffen · 2025-09-06T22:41:50Z

Moved a Box::new to try and fix regressions. Profiling shows the regressions are in parse_param_general::{closure#0}.

ZuseZ4 · 2025-09-06T22:51:21Z

@bors2 try @rust-timer queue

Remove boxes from ast list elements

rust-bors · 2025-09-07T01:08:42Z

☀️ Try build successful (CI)
Build commit: 4c3b5d3 (4c3b5d3811bd68ed990231b0dcfaad8b5ab255af, parent: 1ed3cd7030718935a5c5e5c8f6581f36d8be179f)

rust-timer · 2025-09-07T02:23:25Z

Finished benchmarking commit (4c3b5d3): comparison URL.

Overall result: ❌ regressions - please read the text below

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.

Next Steps: If you can justify the regressions found in this try perf run, please do so in sufficient writing along with @rustbot label: +perf-regression-triaged. If not, please fix the regressions and do another perf run. If its results are neutral or positive, the label will be automatically removed.

@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)	0.4%	[0.1%, 0.8%]	19
Regressions ❌ (secondary)	0.2%	[0.1%, 0.4%]	22
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.4%	[-0.5%, -0.3%]	3
All ❌✅ (primary)	0.4%	[0.1%, 0.8%]	19

Max RSS (memory usage)

Results (primary 1.3%, secondary -2.2%)

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

	mean	range	count
Regressions ❌ (primary)	1.3%	[1.3%, 1.3%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-2.2%	[-3.4%, -0.7%]	4
All ❌✅ (primary)	1.3%	[1.3%, 1.3%]	1

Cycles

Results (primary 3.1%)

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

	mean	range	count
Regressions ❌ (primary)	3.1%	[3.1%, 3.1%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	3.1%	[3.1%, 3.1%]	1

Binary size

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

Bootstrap: 465.747s -> 468.049s (0.49%)
Artifact size: 387.43 MiB -> 387.47 MiB (0.01%)

camsteffen · 2025-09-07T13:18:42Z

@rustbot author

rust-bors · 2025-10-05T07:52:41Z

💥 Test timed out after 21600s

camsteffen · 2025-10-07T20:22:26Z

@ZuseZ4 can you give it another try?

ZuseZ4 · 2025-10-07T20:25:56Z

@bors2 try @rust-timer queue

Remove boxes from ast list elements

rust-bors · 2025-10-07T22:41:32Z

☀️ Try build successful (CI)
Build commit: c10c5b1 (c10c5b1ea7de995e6ec34ef6dcda49324b4c2810, parent: fed46ffd5059e11669df1bd9406b02914c3fb73f)

rust-timer · 2025-10-08T00:59:29Z

Finished benchmarking commit (c10c5b1): comparison URL.

Overall result: ❌✅ regressions and 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)	0.2%	[0.2%, 0.2%]	1
Improvements ✅ (primary)	-0.2%	[-0.2%, -0.2%]	2
Improvements ✅ (secondary)	-0.0%	[-0.0%, -0.0%]	1
All ❌✅ (primary)	-0.2%	[-0.2%, -0.2%]	2

Max RSS (memory usage)

Results (primary -2.4%, secondary -0.8%)

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)	1.7%	[0.9%, 2.4%]	2
Improvements ✅ (primary)	-2.4%	[-3.2%, -1.6%]	2
Improvements ✅ (secondary)	-2.0%	[-2.6%, -0.6%]	4
All ❌✅ (primary)	-2.4%	[-3.2%, -1.6%]	2

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: 474.165s -> 473.322s (-0.18%)
Artifact size: 388.38 MiB -> 388.39 MiB (0.00%)

camsteffen · 2025-10-08T02:25:29Z

This looks like a small win now. I think the one regression is noise.

@rustbot ready

cjgillot · 2025-10-15T16:22:48Z

Thanks! The code is even a bit cleaner.
@bors r+

bors · 2025-10-15T16:22:51Z

📌 Commit 0ea65e0 has been approved by cjgillot

It is now in the queue for this repository.

bors · 2025-10-16T02:31:47Z

⌛ Testing commit 0ea65e0 with merge f524236...

bors · 2025-10-16T05:36:48Z

☀️ Test successful - checks-actions
Approved by: cjgillot
Pushing f524236 to master...

github-actions · 2025-10-16T05:40:02Z

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 402ce0e (parent) -> f524236 (this PR)

Test differences

Show 10 test diffs

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

Test dashboard

Run

cargo run --manifest-path src/ci/citool/Cargo.toml -- \
    test-dashboard f5242367f4acf0130c9b68e6956531b2cb73bd38 --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: 6985.7s -> 9880.1s (41.4%)
aarch64-apple: 8235.5s -> 10172.0s (23.5%)
dist-apple-various: 4036.2s -> 4817.9s (19.4%)
pr-check-1: 1757.8s -> 1541.4s (-12.3%)
test-various: 4334.8s -> 4791.1s (10.5%)
dist-aarch64-apple: 7990.0s -> 8689.0s (8.7%)
x86_64-gnu-tools: 3707.9s -> 3390.3s (-8.6%)
x86_64-msvc-ext2: 6309.5s -> 5787.9s (-8.3%)
i686-msvc-1: 10301.7s -> 9544.6s (-7.3%)
dist-aarch64-msvc: 5407.3s -> 5735.0s (6.1%)

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 · 2025-10-16T07:36:45Z

Finished benchmarking commit (f524236): comparison URL.

Overall result: ❌✅ regressions and improvements - no action needed

@rustbot label: -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)	0.1%	[0.1%, 0.1%]	2
Improvements ✅ (primary)	-0.2%	[-0.2%, -0.2%]	1
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-0.2%	[-0.2%, -0.2%]	1

Max RSS (memory usage)

Results (secondary 0.6%)

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)	1.2%	[0.7%, 1.7%]	5
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-2.4%	[-2.4%, -2.4%]	1
All ❌✅ (primary)	-	-	0

Cycles

Results (primary 2.4%, secondary 2.0%)

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

	mean	range	count
Regressions ❌ (primary)	2.4%	[2.4%, 2.4%]	1
Regressions ❌ (secondary)	2.0%	[2.0%, 2.0%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	2.4%	[2.4%, 2.4%]	1

Binary size

Results (secondary -0.0%)

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)	-	-	0
Improvements ✅ (secondary)	-0.0%	[-0.0%, -0.0%]	1
All ❌✅ (primary)	-	-	0

Bootstrap: 474.904s -> 475.759s (0.18%)
Artifact size: 388.04 MiB -> 388.06 MiB (0.01%)

Remove boxes from ast list elements Less indirection should be better perf.

rustbot assigned spastorino Sep 5, 2025

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rust-bors Bot added a commit that referenced this pull request Sep 5, 2025

Auto merge of #146221 - camsteffen:ast-boxes, r=<try>

cd2fe74

Remove boxes from ast list elements

rustbot added the S-waiting-on-perf Status: Waiting on a perf run to be completed. label Sep 5, 2025

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rustbot added perf-regression Performance regression. and removed S-waiting-on-perf Status: Waiting on a perf run to be completed. labels Sep 5, 2025

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rust-bors Bot added a commit that referenced this pull request Sep 6, 2025

Auto merge of #146221 - camsteffen:ast-boxes, r=<try>

4c3b5d3

Remove boxes from ast list elements

rustbot added the S-waiting-on-perf Status: Waiting on a perf run to be completed. label Sep 6, 2025

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rustbot removed the S-waiting-on-perf Status: Waiting on a perf run to be completed. label Sep 7, 2025

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rust-bors Bot added a commit that referenced this pull request Oct 7, 2025

Auto merge of #146221 - camsteffen:ast-boxes, r=<try>

c10c5b1

Remove boxes from ast list elements

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rustbot removed the S-waiting-on-perf Status: Waiting on a perf run to be completed. label Oct 8, 2025

rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. and removed S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. labels Oct 8, 2025

bors 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 Oct 15, 2025

bors added the merged-by-bors This PR was explicitly merged by bors. label Oct 16, 2025

bors merged commit f524236 into rust-lang:master Oct 16, 2025
12 checks passed

rustbot added this to the 1.92.0 milestone Oct 16, 2025

This was referenced Oct 16, 2025

Add NonNull pattern types #142339

Merged

Externally implementable items #146348

Merged

flip1995 pushed a commit to flip1995/rust that referenced this pull request Oct 31, 2025

Auto merge of rust-lang#146221 - camsteffen:ast-boxes, r=cjgillot

2c8a9e2

Remove boxes from ast list elements Less indirection should be better perf.

makai410 pushed a commit to makai410/rust that referenced this pull request Nov 8, 2025

Auto merge of rust-lang#146221 - camsteffen:ast-boxes, r=cjgillot

80abe9c

Remove boxes from ast list elements Less indirection should be better perf.

makai410 pushed a commit to makai410/rust that referenced this pull request Nov 10, 2025

Auto merge of rust-lang#146221 - camsteffen:ast-boxes, r=cjgillot

c2caa30

Remove boxes from ast list elements Less indirection should be better perf.

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rust-timer commented Sep 5, 2025

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

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Overall result: ❌ regressions - please read the text below

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Overall result: ❌✅ regressions and improvements - no action needed

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Test differences

Job duration changes

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rust-timer commented Oct 16, 2025

Overall result: ❌✅ regressions and improvements - no action needed

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9 participants