improve AttrTokenStream

[kiscad]

Improve the performance of AttrTokenStream::to_tokenstream method

[rustbot]

r? @compiler-errors

(rustbot has picked a reviewer for you, use r? to override)

[kiscad]

r? @petrochenkov

[rustbot]

Could not assign reviewer from: petrochenkov.
User(s) petrochenkov are either the PR author, already assigned, or on vacation, and there are no other candidates.
Use r? to specify someone else to assign.

[petrochenkov]

@bors try @rust-timer queue

[bors]

⌛ Trying commit f404990 with merge 940bc63a1822b2b7dd2068b9a03ee4f749c62f5a...

[bors]

☀️ Try build successful - checks-actions
Build commit: 940bc63a1822b2b7dd2068b9a03ee4f749c62f5a (940bc63a1822b2b7dd2068b9a03ee4f749c62f5a)

[rust-timer]

Finished benchmarking commit (940bc63a1822b2b7dd2068b9a03ee4f749c62f5a): comparison URL.

Overall result: ❌✅ regressions and 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)	0.6%	[0.6%, 0.6%]	2
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.2%	[-0.2%, -0.2%]	1
All ❌✅ (primary)	0.6%	[0.6%, 0.6%]	2

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)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-3.2%	[-3.2%, -3.2%]	1
All ❌✅ (primary)	-	-	0

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: 627.22s -> 627.867s (0.10%)
Artifact size: 316.03 MiB -> 316.04 MiB (0.00%)

[kiscad]

https://perf.rust-lang.org/compare.html?start=bf1e3f31f95c0f75b9bf51a58e8684f750f919f2&end=940bc63a1822b2b7dd2068b9a03ee4f749c62f5a&stat=instructions%3Au&nonRelevant=true

It looks that the average performance has a minor improvement, about 0.05%.

[petrochenkov]

The perf changes are most likely noise, but the PR doesn't complicate code so we can merge it.
@bors r+ rollup

[bors]

📌 Commit f404990 has been approved by petrochenkov

It is now in the queue for this repository.

[klensy]

How this works? Attributes in AttrVec here contained in unspecified order and partition_point should return some meaningless result. And no test failure.

[petrochenkov]

Attributes are supposed to always be partitioned #[outer1] #[outer2] { #![inner1] #![inner2] } because they go in left-to-right order.