Revert "increase perf of charsearcher for single ascii characters"

[Kobzol]

This reverts commit 245bf50 (PR #141516).

It caused a large doc perf. regression in #141605.

[Kobzol]

@bors try @rust-timer queue

[bors]

⌛ Trying commit cd4f199 with merge 74d6826...

[bors]

☀️ Try build successful - checks-actions
Build commit: 74d6826 (74d6826c92a6fb600ec35ea03b819563c1c863a6)

[rust-timer]

Finished benchmarking commit (74d6826): comparison URL.

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

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 the most reliable metric that we have; it was used to determine the overall result at the top of this comment. However, even this metric can sometimes exhibit noise.

	mean	range	count
Regressions ❌ (primary)	1.4%	[0.4%, 2.2%]	3
Regressions ❌ (secondary)	0.9%	[0.9%, 0.9%]	1
Improvements ✅ (primary)	-1.3%	[-7.3%, -0.1%]	37
Improvements ✅ (secondary)	-1.5%	[-2.6%, -0.3%]	22
All ❌✅ (primary)	-1.1%	[-7.3%, 2.2%]	40

Max RSS (memory usage)

Results (primary 0.2%, secondary -4.7%)

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)	1.5%	[0.8%, 2.2%]	2
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-2.3%	[-2.3%, -2.3%]	1
Improvements ✅ (secondary)	-4.7%	[-4.7%, -4.7%]	1
All ❌✅ (primary)	0.2%	[-2.3%, 2.2%]	3

Cycles

Results (primary -0.4%)

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)	1.8%	[0.8%, 2.7%]	3
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-2.0%	[-3.8%, -0.8%]	4
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-0.4%	[-3.8%, 2.7%]	7

Binary size

Results (primary 0.0%, secondary 0.1%)

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)	0.2%	[0.0%, 0.9%]	8
Regressions ❌ (secondary)	0.2%	[0.1%, 0.4%]	38
Improvements ✅ (primary)	-0.2%	[-0.5%, -0.0%]	7
Improvements ✅ (secondary)	-0.6%	[-0.7%, -0.3%]	4
All ❌✅ (primary)	0.0%	[-0.5%, 0.9%]	15

Bootstrap: 778.064s -> 779.335s (0.16%)
Artifact size: 368.46 MiB -> 368.45 MiB (-0.00%)

[Kobzol]

Huh, the doc regressions in #141605 were from this PR, who knew.

[Kobzol]

@workingjubilee #141516 (comment) famous last words xD Should we revert?

[workingjubilee]

hand me my hat, tonight's dinner has been picked for me

sigh!

r=me if undrafted

[rustbot]

r? @thomcc

rustbot has assigned @thomcc.
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

[Kobzol]

r? @workingjubilee

@bors r=workingjubilee

Also CC @bend-n.

[bors]

📌 Commit cd4f199 has been approved by workingjubilee

It is now in the queue for this repository.

[bend-n]

i wonder if it would not cause a perf regression if i used memchr instead of iter::position

[Kobzol]

Feel free to send the PR again (once the revert is merged) and we can do a perf. run to try out! :)

[bors]

⌛ Testing commit cd4f199 with merge e0d014a...

[bors]

☀️ Test successful - checks-actions
Approved by: workingjubilee
Pushing e0d014a to master...

[github-actions]

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 ec28ae9 (parent) -> e0d014a (this PR)

Test differences

Show 24 test diffs

24 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 e0d014a3dffbb3f0575cfbeb0f480c5080c4d018 --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

1. dist-aarch64-linux: 7561.4s -> 5730.5s (-24.2%)
2. dist-x86_64-apple: 7677.4s -> 8900.4s (15.9%)
3. dist-aarch64-apple: 5159.1s -> 5582.9s (8.2%)
4. dist-apple-various: 6813.2s -> 7333.6s (7.6%)
5. x86_64-apple-2: 5134.3s -> 4757.4s (-7.3%)
6. x86_64-apple-1: 8282.7s -> 8881.7s (7.2%)
7. aarch64-apple: 5129.2s -> 4816.8s (-6.1%)
8. aarch64-gnu: 6631.2s -> 7031.3s (6.0%)
9. dist-android: 2434.7s -> 2580.1s (6.0%)
10. dist-ohos-aarch64: 4734.1s -> 4472.1s (-5.5%)

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]

Finished benchmarking commit (e0d014a): comparison URL.

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

Our benchmarks found a performance regression caused by this PR.
This might be an actual regression, but it can also be just noise.

Next Steps:

• If the regression was expected or you think it can be justified,
  please write a comment with sufficient written justification, and add
  @rustbot label: +perf-regression-triaged to it, to mark the regression as triaged.
• If you think that you know of a way to resolve the regression, try to create
  a new PR with a fix for the regression.
• If you do not understand the regression or you think that it is just noise,
  you can ask the @rust-lang/wg-compiler-performance working group for help (members of this group
  were already notified of this PR).

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

Instruction count

This is the most reliable metric that we have; it was used to determine the overall result at the top of this comment. However, even this metric can sometimes exhibit noise.

	mean	range	count
Regressions ❌ (primary)	1.9%	[1.6%, 2.2%]	2
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-1.4%	[-7.3%, -0.2%]	36
Improvements ✅ (secondary)	-1.6%	[-4.2%, -0.3%]	25
All ❌✅ (primary)	-1.2%	[-7.3%, 2.2%]	38

Max RSS (memory usage)

Results (primary 2.0%, secondary 0.8%)

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)	4.1%	[1.7%, 6.3%]	4
Regressions ❌ (secondary)	1.1%	[0.4%, 3.0%]	11
Improvements ✅ (primary)	-6.1%	[-6.1%, -6.1%]	1
Improvements ✅ (secondary)	-0.8%	[-1.0%, -0.6%]	2
All ❌✅ (primary)	2.0%	[-6.1%, 6.3%]	5

Cycles

Results (primary -0.9%, secondary 0.3%)

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)	2.0%	[1.6%, 2.4%]	2
Regressions ❌ (secondary)	2.2%	[0.5%, 5.4%]	6
Improvements ✅ (primary)	-2.3%	[-3.5%, -1.0%]	4
Improvements ✅ (secondary)	-0.8%	[-1.1%, -0.4%]	11
All ❌✅ (primary)	-0.9%	[-3.5%, 2.4%]	6

Binary size

Results (primary -0.1%, secondary 0.1%)

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)	0.2%	[0.0%, 0.9%]	11
Regressions ❌ (secondary)	0.2%	[0.1%, 0.4%]	38
Improvements ✅ (primary)	-0.3%	[-1.2%, -0.0%]	10
Improvements ✅ (secondary)	-0.6%	[-0.7%, -0.3%]	4
All ❌✅ (primary)	-0.1%	[-1.2%, 0.9%]	21

Bootstrap: 776.684s -> 777.196s (0.07%)
Artifact size: 370.33 MiB -> 370.47 MiB (0.04%)