Turn on ConstDebugInfo pass.

[cjgillot]

Split from #103657

Moving those constant into debuginfo allows to shrink the number of locals and the actual size of the MIR body.

[cjgillot]

@bors try @rust-timer queue

[bors]

⌛ Trying commit 01e364ee80f8a6569ffd131f1eaa6cbdd1e2df37 with merge d908afcacb9fa8badcf4d4fb4355dfa77efb81d4...

[bors]

☀️ Try build successful - checks-actions
Build commit: d908afcacb9fa8badcf4d4fb4355dfa77efb81d4 (d908afcacb9fa8badcf4d4fb4355dfa77efb81d4)

[rust-timer]

Finished benchmarking commit (d908afcacb9fa8badcf4d4fb4355dfa77efb81d4): 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
Regressions ❌ (secondary)	3.8%	[3.8%, 3.8%]	1
Improvements ✅ (primary)	-0.9%	[-0.9%, -0.9%]	1
Improvements ✅ (secondary)	-0.8%	[-1.2%, -0.4%]	2
All ❌✅ (primary)	-0.9%	[-0.9%, -0.9%]	1

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)	2.8%	[2.8%, 2.8%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-3.3%	[-3.4%, -3.2%]	2
Improvements ✅ (secondary)	-1.5%	[-2.0%, -1.3%]	3
All ❌✅ (primary)	-1.3%	[-3.4%, 2.8%]	3

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)	-0.9%	[-0.9%, -0.9%]	1
Improvements ✅ (secondary)	-2.5%	[-2.5%, -2.5%]	1
All ❌✅ (primary)	-0.9%	[-0.9%, -0.9%]	1

[bors]

☔ The latest upstream changes (presumably #107727) made this pull request unmergeable. Please resolve the merge conflicts.

[rustbot]

Some changes occurred to MIR optimizations

cc @rust-lang/wg-mir-opt

[cjgillot]

r? compiler

[oli-obk]

Tiny, but consistent, regression in debug mode binary size (https://perf.rust-lang.org/compare.html?start=252741673b9c2b06267cd3a036d77489e92f963a&end=d908afcacb9fa8badcf4d4fb4355dfa77efb81d4&stat=size%3Alinked_artifact), but that's ok, just a bit of debuginfo shuffling.

@bors r+

[bors]

📌 Commit f15c14f2d6888da6bf4356bb2ab090ee6a658f9b has been approved by oli-obk

It is now in the queue for this repository.

[bors]

⌛ Testing commit f15c14f2d6888da6bf4356bb2ab090ee6a658f9b with merge 2c15a814665491718d25a12f8a6473bfbf6f628a...

[bors]

💔 Test failed - checks-actions

[cjgillot]

@bors r=oli-obk

[bors]

📌 Commit b8c67d8 has been approved by oli-obk

It is now in the queue for this repository.

[bors]

⌛ Testing commit b8c67d8 with merge 9e540df...

[bors]

☀️ Test successful - checks-actions
Approved by: oli-obk
Pushing 9e540df to master...

[rust-timer]

Finished benchmarking commit (9e540df): 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)	0.4%	[0.2%, 0.7%]	12
Regressions ❌ (secondary)	0.4%	[0.4%, 0.4%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.3%	[-0.3%, -0.3%]	2
All ❌✅ (primary)	0.4%	[0.2%, 0.7%]	12

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)	3.3%	[0.8%, 6.1%]	3
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	3.3%	[0.8%, 6.1%]	3

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)	1.0%	[1.0%, 1.0%]	1
Regressions ❌ (secondary)	3.1%	[3.1%, 3.1%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-11.6%	[-14.3%, -5.5%]	4
All ❌✅ (primary)	1.0%	[1.0%, 1.0%]	1

[nnethercote]

@oli-obk: the post-merge results look quite different. Any idea why?

[oli-obk]

Well, we add more info to debuginfo, it could be that LLVM now shuffles codegen units differently or just randomly takes more time. We'll need to see if these benchmarks had a single bump or if they are now more noisy.