don't store opaque info during encoding

[bvanjoi]

Now remapped_ctxts reserved and let's check the performance.

r? @petrochenkov

[lqd]

@bors try @rust-timer queue

[bors]

⌛ Trying commit 941e1ef with merge 5fe2fa1...

[bors]

☀️ Try build successful - checks-actions
Build commit: 5fe2fa1 (5fe2fa19dccbc7033df9d47ca2be3c9c658e1fb5)

[rust-timer]

Finished benchmarking commit (5fe2fa1): 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)	0.9%	[0.3%, 1.1%]	5
Regressions ❌ (secondary)	0.4%	[0.2%, 0.9%]	12
Improvements ✅ (primary)	-0.3%	[-0.5%, -0.2%]	13
Improvements ✅ (secondary)	-0.4%	[-0.5%, -0.1%]	16
All ❌✅ (primary)	0.0%	[-0.5%, 1.1%]	18

Max RSS (memory usage)

Results (primary 0.2%, secondary 2.4%)

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)	2.4%	[2.4%, 2.4%]	1
Regressions ❌ (secondary)	2.4%	[1.9%, 2.8%]	2
Improvements ✅ (primary)	-1.9%	[-1.9%, -1.9%]	1
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.2%	[-1.9%, 2.4%]	2

Cycles

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

Binary size

Results (primary -0.2%, secondary -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)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-0.2%	[-0.9%, -0.0%]	121
Improvements ✅ (secondary)	-0.4%	[-0.9%, -0.1%]	37
All ❌✅ (primary)	-0.2%	[-0.9%, -0.0%]	121

Bootstrap: 775.08s -> 774.329s (-0.10%)
Artifact size: 365.94 MiB -> 365.94 MiB (-0.00%)

[petrochenkov]

Instruction results are mixed, but it's a clear improvement in binary sizes.
I want to try one more thing before merging this.

[petrochenkov]

Blocked on #139281.
@rustbot blocked

[petrochenkov]

#139281 has landed.
@rustbot author

[rustbot]

Reminder, once the PR becomes ready for a review, use @rustbot ready.

[bvanjoi]

I have a few questions here:

1. Does this imply we should close the current PR?
2. If we stick with storing only SyntaxContextKey in the disk cache, we’d simply be changing SyntaxContextDataNonRecursive to SyntaxContextKey — which would essentially leave things as they are now.

[petrochenkov]

Does this imply we should close the current PR?

I think we should at least measure the effect (incl. binary size).

we’d simply be changing SyntaxContextDataNonRecursive to SyntaxContextKey — which would essentially leave things as they are now.

In the first case we encode more and decode more, in the second case we encode less, decode less but re-calculate more. Not exactly the same.

[petrochenkov]

@bors try @rust-timer queue

[bors]

⌛ Trying commit 8ae6485 with merge e3fff58...

[bors]

☀️ Try build successful - checks-actions
Build commit: e3fff58 (e3fff58fa34c73361d7bda6ee094298a7421f243)

[rust-timer]

Finished benchmarking commit (e3fff58): comparison URL.

Overall result: no relevant changes - 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 benchmark run did not return any relevant results for this metric.

Max RSS (memory usage)

Results (primary -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)	3.3%	[3.3%, 3.3%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-2.9%	[-3.4%, -2.4%]	2
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-0.8%	[-3.4%, 3.3%]	3

Cycles

Results (secondary 3.5%)

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)	3.5%	[3.5%, 3.5%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Binary size

Results (primary -0.2%, 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)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-0.2%	[-0.5%, -0.0%]	92
Improvements ✅ (secondary)	-0.3%	[-0.7%, -0.0%]	37
All ❌✅ (primary)	-0.2%	[-0.5%, -0.0%]	92

Bootstrap: 776.898s -> 777.128s (0.03%)
Artifact size: 365.51 MiB -> 365.49 MiB (-0.01%)

[petrochenkov]

Let's land this, it's a clear code simplification and binary size improvement, and the perf changes are within the noise level.
@bors r+

[bors]

📌 Commit 8ae6485 has been approved by petrochenkov

It is now in the queue for this repository.

[bors]

⌛ Testing commit 8ae6485 with merge c580c49...

[bors]

☀️ Test successful - checks-actions
Approved by: petrochenkov
Pushing c580c49 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 5961e5b (parent) -> c580c49 (this PR)

Test differences

Show 8 test diffs

Additionally, 8 doctest diffs were found. These are ignored, as they are noisy.

Job group index

Job duration changes

1. x86_64-apple-2: 5044.6s -> 6506.7s (29.0%)
2. dist-x86_64-apple: 10770.2s -> 7945.5s (-26.2%)
3. x86_64-apple-1: 7102.8s -> 8751.6s (23.2%)
4. x86_64-gnu-debug: 6486.8s -> 6140.2s (-5.3%)
5. dist-x86_64-msvc: 6203.4s -> 5954.5s (-4.0%)
6. dist-apple-various: 6877.8s -> 6608.8s (-3.9%)
7. aarch64-gnu-debug: 4279.9s -> 4112.6s (-3.9%)
8. i686-msvc-1: 9750.2s -> 9391.9s (-3.7%)
9. dist-aarch64-apple: 4717.2s -> 4890.0s (3.7%)
10. dist-powerpc-linux: 5454.1s -> 5265.6s (-3.5%)

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 (c580c49): comparison URL.

Overall result: no relevant changes - no action needed

@rustbot label: -perf-regression

Instruction count

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

Max RSS (memory usage)

Results (primary 0.5%)

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%	[0.5%, 0.6%]	5
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.5%	[0.5%, 0.6%]	5

Cycles

Results (primary 2.1%, 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)	2.1%	[2.1%, 2.1%]	1
Regressions ❌ (secondary)	2.1%	[2.1%, 2.1%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-2.4%	[-2.4%, -2.4%]	1
All ❌✅ (primary)	2.1%	[2.1%, 2.1%]	1

Binary size

Results (primary -0.2%, 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)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-0.2%	[-0.5%, -0.0%]	92
Improvements ✅ (secondary)	-0.3%	[-0.7%, -0.0%]	37
All ❌✅ (primary)	-0.2%	[-0.5%, -0.0%]	92

Bootstrap: 784.641s -> 784.038s (-0.08%)
Artifact size: 365.11 MiB -> 365.12 MiB (0.00%)