Avoid cloning a collection only to iterate over it

[kadiwa4]

@rustbot label: +C-cleanup

[rust-highfive]

r? @CraftSpider

(rust-highfive has picked a reviewer for you, use r? to override)

[cjgillot]

@bors r+ rollup=iffy

[bors]

📌 Commit 4eebcb9 has been approved by cjgillot

It is now in the queue for this repository.

[compiler-errors]

Gonna do a perf run on this, if it's perf-sensitive then let's leave it as rollup=never, otherwise we can make it rollup=maybe

@bors try @rust-timer queue

[rust-timer]

Awaiting bors try build completion.

@rustbot label: +S-waiting-on-perf

[bors]

🙅 Please do not try after a pull request has been r+ed. If you need to try, unapprove (r-) it first.

[compiler-errors]

@bors r-

[compiler-errors]

@bors try @rust-timer queue

[rust-timer]

Awaiting bors try build completion.

@rustbot label: +S-waiting-on-perf

[compiler-errors]

(i'm doing this because the rollup=iffy list is super long and it's probably not getting any shorter)

[compiler-errors]

@bors try

[bors]

⌛ Trying commit 4eebcb9 with merge feb1ea3e27edab7fa9b1eb2edfe0f46c52711ca8...

[bors]

☀️ Try build successful - checks-actions
Build commit: feb1ea3e27edab7fa9b1eb2edfe0f46c52711ca8 (feb1ea3e27edab7fa9b1eb2edfe0f46c52711ca8)

[rust-timer]

Queued feb1ea3e27edab7fa9b1eb2edfe0f46c52711ca8 with parent c07a8b4, future comparison URL.

[rust-timer]

Finished benchmarking commit (feb1ea3e27edab7fa9b1eb2edfe0f46c52711ca8): comparison URL.

Overall result: ❌✅ regressions and improvements - ACTION NEEDED

Benchmarking this pull request likely means that it is perf-sensitive, so we're automatically marking it as not fit for rolling up. While you can manually mark this PR as fit for rollup, we strongly recommend not doing so since this PR may lead to changes in compiler perf.

Next Steps: If you can justify the regressions found in this try perf run, please indicate this with @rustbot label: +perf-regression-triaged along with sufficient written justification. If you cannot justify the regressions please fix the regressions and do another perf run. If the next run shows neutral or positive results, the label will be automatically removed.

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

Instruction count

This is a highly reliable metric that was used to determine the overall result at the top of this comment.

	mean1	range	count2
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	0.2%	[0.2%, 0.3%]	3
Improvements ✅ (primary)	-0.5%	[-0.7%, -0.3%]	4
Improvements ✅ (secondary)	-0.9%	[-1.2%, -0.5%]	8
All ❌✅ (primary)	-0.5%	[-0.7%, -0.3%]	4

Max RSS (memory usage)

Results

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean1	range	count2
Regressions ❌ (primary)	2.4%	[2.4%, 2.4%]	1
Regressions ❌ (secondary)	5.9%	[2.1%, 9.7%]	2
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	2.4%	[2.4%, 2.4%]	1

Cycles

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

Footnotes

1. the arithmetic mean of the percent change ↩ ↩²

2. number of relevant changes ↩ ↩²

[compiler-errors]

Secondary regressions are outweighed by primary and secondary improvements.

@bors r=cjgillot rollup=never

[bors]

📌 Commit 4eebcb9 has been approved by cjgillot

It is now in the queue for this repository.

[bors]

⌛ Testing commit 4eebcb9 with merge ce36e88...

[bors]

☀️ Test successful - checks-actions
Approved by: cjgillot
Pushing ce36e88 to master...

[rust-timer]

Finished benchmarking commit (ce36e88): comparison URL.

Overall result: ❌✅ regressions and improvements - ACTION NEEDED

Next Steps: If you can justify the regressions found in this perf run, please indicate this with @rustbot label: +perf-regression-triaged along with sufficient written justification. If you cannot justify the regressions please open an issue or create a new PR that fixes the regressions, add a comment linking to the newly created issue or PR, and then add the perf-regression-triaged label to this PR.

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

Instruction count

This is a highly reliable metric that was used to determine the overall result at the top of this comment.

	mean1	range	count2
Regressions ❌ (primary)	0.5%	[0.5%, 0.6%]	6
Regressions ❌ (secondary)	0.8%	[0.5%, 1.1%]	10
Improvements ✅ (primary)	-0.6%	[-0.8%, -0.5%]	3
Improvements ✅ (secondary)	-1.0%	[-1.2%, -0.5%]	4
All ❌✅ (primary)	0.2%	[-0.8%, 0.6%]	9

Max RSS (memory usage)

Results

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean1	range	count2
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-1.3%	[-1.3%, -1.3%]	1
All ❌✅ (primary)	-	-	0

Cycles

Results

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean1	range	count2
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-4.1%	[-4.2%, -4.0%]	2
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-4.1%	[-4.2%, -4.0%]	2

Footnotes

1. the arithmetic mean of the percent change ↩ ↩² ↩³

2. number of relevant changes ↩ ↩² ↩³

[nnethercote]

html5ever-0.26.0 has been noisy recently, so I think those numbers can be ignored. The doc improvements for webrender, syn and regex look like they're real, because they were seen on both perf runs. The other changes are iffy, may just be noise.