Less generic code for Vec allocations

[kornelski]

Follow up to #120504 (comment) which hopefully makes compilation faster.

[rustbot]

r? @joboet

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

Use r? to explicitly pick a reviewer

[Noratrieb]

@bors try @rust-timer queue

[bors]

⌛ Trying commit 870d332 with merge 5af3381...

[bors]

☀️ Try build successful - checks-actions
Build commit: 5af3381 (5af33816ce489bad2f393d82636f8c65bd99ba55)

[rust-timer]

Finished benchmarking commit (5af3381): comparison URL.

Overall result: ✅ improvements - no 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.

@bors rollup=never
@rustbot label: -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.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-0.7%	[-1.4%, -0.5%]	8
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-0.7%	[-1.4%, -0.5%]	8

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.

	mean	range	count
Regressions ❌ (primary)	4.4%	[1.0%, 8.3%]	7
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-16.7%	[-16.7%, -16.7%]	1
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	1.7%	[-16.7%, 8.3%]	8

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.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-1.8%	[-1.8%, -1.8%]	1
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-1.8%	[-1.8%, -1.8%]	1

Binary size

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.

	mean	range	count
Regressions ❌ (primary)	0.5%	[0.0%, 1.8%]	7
Regressions ❌ (secondary)	0.0%	[0.0%, 0.0%]	11
Improvements ✅ (primary)	-0.3%	[-0.9%, -0.0%]	68
Improvements ✅ (secondary)	-0.3%	[-0.5%, -0.2%]	7
All ❌✅ (primary)	-0.2%	[-0.9%, 1.8%]	75

Bootstrap: 672.776s -> 672.488s (-0.04%)
Artifact size: 310.29 MiB -> 310.20 MiB (-0.03%)

[joboet]

Looks like there are some very small performance gains, and this makes sense to me from a readability standpoint.

Just two things, and then this should be good to go!

[joboet]

@bors try @rust-timer queue

[bors]

⌛ Trying commit a7064e1 with merge 918ae71...

[rust-timer]

Finished benchmarking commit (918ae71): 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-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.

	mean	range	count
Regressions ❌ (primary)	0.7%	[0.7%, 0.7%]	2
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-0.7%	[-1.3%, -0.5%]	6
Improvements ✅ (secondary)	-4.4%	[-4.4%, -4.4%]	1
All ❌✅ (primary)	-0.4%	[-1.3%, 0.7%]	8

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.

	mean	range	count
Regressions ❌ (primary)	6.1%	[3.3%, 8.1%]	5
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-2.7%	[-18.0%, -1.3%]	39
Improvements ✅ (secondary)	-2.7%	[-4.2%, -0.7%]	66
All ❌✅ (primary)	-1.7%	[-18.0%, 8.1%]	44

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.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	4.1%	[3.5%, 4.6%]	2
Improvements ✅ (primary)	-1.7%	[-1.7%, -1.6%]	2
Improvements ✅ (secondary)	-2.6%	[-2.6%, -2.6%]	1
All ❌✅ (primary)	-1.7%	[-1.7%, -1.6%]	2

Binary size

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.

	mean	range	count
Regressions ❌ (primary)	0.5%	[0.0%, 1.9%]	8
Regressions ❌ (secondary)	0.0%	[0.0%, 0.0%]	11
Improvements ✅ (primary)	-0.3%	[-0.8%, -0.0%]	67
Improvements ✅ (secondary)	-0.2%	[-0.3%, -0.2%]	4
All ❌✅ (primary)	-0.2%	[-0.8%, 1.9%]	75

Bootstrap: 669.125s -> 667.891s (-0.18%)
Artifact size: 311.46 MiB -> 311.42 MiB (-0.01%)

[workingjubilee]

@bors r=joboet

[bors]

📌 Commit 533d7d1 has been approved by joboet

It is now in the queue for this repository.

[bors]

⌛ Testing commit 533d7d1 with merge 8de7649...

[bors]

💔 Test failed - checks-actions

[kornelski]

I've removed word "reserve" from helper function name to avoid confusing tests that look for absence of functions like try_reserve.

[joboet]

Cool! r=me once CI comes in green.

[joboet]

@bors r+

[bors]

📌 Commit 443e29c has been approved by joboet

It is now in the queue for this repository.

[bors]

⌛ Testing commit 443e29c with merge c9f8f34...

[bors]

☀️ Test successful - checks-actions
Approved by: joboet
Pushing c9f8f34 to master...

[rust-timer]

Finished benchmarking commit (c9f8f34): 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.

	mean	range	count
Regressions ❌ (primary)	0.6%	[0.3%, 0.8%]	2
Regressions ❌ (secondary)	0.3%	[0.3%, 0.3%]	1
Improvements ✅ (primary)	-0.5%	[-1.4%, -0.1%]	12
Improvements ✅ (secondary)	-4.4%	[-4.4%, -4.4%]	1
All ❌✅ (primary)	-0.3%	[-1.4%, 0.8%]	14

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.

	mean	range	count
Regressions ❌ (primary)	3.2%	[0.6%, 5.8%]	2
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-1.5%	[-4.7%, -0.2%]	12
Improvements ✅ (secondary)	-3.6%	[-3.6%, -3.6%]	1
All ❌✅ (primary)	-0.8%	[-4.7%, 5.8%]	14

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.

	mean	range	count
Regressions ❌ (primary)	0.7%	[0.5%, 1.0%]	6
Regressions ❌ (secondary)	3.4%	[3.4%, 3.4%]	1
Improvements ✅ (primary)	-1.1%	[-1.8%, -0.5%]	2
Improvements ✅ (secondary)	-3.3%	[-4.3%, -2.4%]	2
All ❌✅ (primary)	0.2%	[-1.8%, 1.0%]	8

Binary size

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.

	mean	range	count
Regressions ❌ (primary)	0.1%	[0.0%, 0.2%]	16
Regressions ❌ (secondary)	0.0%	[0.0%, 0.2%]	15
Improvements ✅ (primary)	-0.2%	[-0.6%, -0.0%]	66
Improvements ✅ (secondary)	-0.2%	[-0.3%, -0.2%]	4
All ❌✅ (primary)	-0.1%	[-0.6%, 0.2%]	82

Bootstrap: 671.34s -> 672.049s (0.11%)
Artifact size: 315.76 MiB -> 315.66 MiB (-0.03%)

[m-ou-se]

We briefly discussed this in the libs meeting, but it didn't seem worth backporting considering the small performance impact.