Add post-mono MIR passes to make mono-reachable analysis more accurate #131650

saethlin · 2024-10-13T12:45:35Z

Debug full/incr-full builds regress, as far as I can tell this is just the expense of cloning, then monomorphizing, then caching the MIR.

saethlin · 2024-10-13T20:06:42Z

@bors try @rust-timer queue

bors · 2024-10-13T20:07:52Z

⌛ Trying commit a211812 with merge b141564...

Add post-mono MIR passes to make mono-reachable analysis more accurate r? ghost

bors · 2024-10-13T21:57:30Z

☀️ Try build successful - checks-actions
Build commit: b141564 (b1415647cdfcdd1b8dc5ed5f9a5aba87ade0b225)

rust-timer · 2024-10-13T23:17:40Z

Finished benchmarking commit (b141564): 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)	12.2%	[0.2%, 93.7%]	163
Regressions ❌ (secondary)	6.9%	[0.2%, 266.3%]	119
Improvements ✅ (primary)	-0.7%	[-3.0%, -0.2%]	6
Improvements ✅ (secondary)	-11.1%	[-33.8%, -0.2%]	12
All ❌✅ (primary)	11.7%	[-3.0%, 93.7%]	169

Max RSS (memory usage)

Results (primary 14.5%, secondary 1.7%)

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)	14.5%	[0.7%, 56.9%]	108
Regressions ❌ (secondary)	4.5%	[0.6%, 12.8%]	34
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-22.2%	[-24.2%, -19.2%]	4
All ❌✅ (primary)	14.5%	[0.7%, 56.9%]	108

Cycles

Results (primary 22.8%, secondary 13.8%)

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)	23.0%	[0.8%, 108.5%]	111
Regressions ❌ (secondary)	19.4%	[1.0%, 223.4%]	42
Improvements ✅ (primary)	-3.0%	[-3.0%, -3.0%]	1
Improvements ✅ (secondary)	-33.2%	[-42.8%, -1.3%]	5
All ❌✅ (primary)	22.8%	[-3.0%, 108.5%]	112

Binary size

Results (primary -0.3%, secondary -2.3%)

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)	0.8%	[0.0%, 2.3%]	7
Regressions ❌ (secondary)	0.1%	[0.1%, 0.1%]	1
Improvements ✅ (primary)	-0.4%	[-1.7%, -0.0%]	76
Improvements ✅ (secondary)	-2.4%	[-25.8%, -0.0%]	65
All ❌✅ (primary)	-0.3%	[-1.7%, 2.3%]	83

Bootstrap: 781.427s -> 807.023s (3.28%)
Artifact size: 331.96 MiB -> 332.21 MiB (0.08%)

saethlin · 2024-10-14T06:14:00Z

@bors try @rust-timer queue

bors · 2024-10-14T06:15:11Z

⌛ Trying commit 6f6737a with merge 9233d9f...

Add post-mono MIR passes to make mono-reachable analysis more accurate r? ghost

bors · 2024-10-14T08:05:01Z

☀️ Try build successful - checks-actions
Build commit: 9233d9f (9233d9f83ca672be3b2cfa697806fdb7c8970490)

rust-timer · 2024-10-14T09:23:57Z

Finished benchmarking commit (9233d9f): 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)	7.6%	[0.1%, 59.9%]	151
Regressions ❌ (secondary)	2.9%	[0.2%, 18.7%]	107
Improvements ✅ (primary)	-3.0%	[-3.0%, -3.0%]	1
Improvements ✅ (secondary)	-6.6%	[-64.0%, -0.3%]	11
All ❌✅ (primary)	7.5%	[-3.0%, 59.9%]	152

Max RSS (memory usage)

Results (primary 11.3%, 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)	12.9%	[1.3%, 52.1%]	93
Regressions ❌ (secondary)	3.6%	[2.2%, 5.9%]	10
Improvements ✅ (primary)	-2.7%	[-4.3%, -0.8%]	10
Improvements ✅ (secondary)	-3.4%	[-3.5%, -3.4%]	2
All ❌✅ (primary)	11.3%	[-4.3%, 52.1%]	103

Cycles

Results (primary 10.6%, secondary 3.2%)

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)	10.7%	[1.0%, 50.1%]	94
Regressions ❌ (secondary)	5.4%	[1.7%, 18.4%]	37
Improvements ✅ (primary)	-3.1%	[-3.1%, -3.1%]	1
Improvements ✅ (secondary)	-17.2%	[-62.3%, -1.6%]	4
All ❌✅ (primary)	10.6%	[-3.1%, 50.1%]	95

Binary size

Results (primary -0.1%, 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)	0.7%	[0.0%, 2.4%]	9
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-0.2%	[-0.8%, -0.0%]	69
Improvements ✅ (secondary)	-0.3%	[-0.8%, -0.0%]	51
All ❌✅ (primary)	-0.1%	[-0.8%, 2.4%]	78

Bootstrap: 782.104s -> 806.252s (3.09%)
Artifact size: 332.57 MiB -> 332.81 MiB (0.07%)

saethlin · 2024-10-24T02:45:21Z

@bors try @rust-timer queue

Add post-mono MIR passes to make mono-reachable analysis more accurate As of rust-lang#131650 (comment) I believe most of the incr overhead comes from re-computing, re-encoding, and loading a lot more MIR when all we're actually doing is traversing through it. I think that can be addressed by caching a query that looks up the mentioned/used items for an Instance. I think the full-build regressions are pretty much just the expense of cloning, then monomorphizing, then caching the MIR.

bors · 2024-10-24T02:46:32Z

⌛ Trying commit 4ae3542 with merge 174810c...

bors · 2025-02-23T17:30:45Z

☔ The latest upstream changes (presumably #137225) made this pull request unmergeable. Please resolve the merge conflicts.

bors · 2025-03-27T11:22:50Z

☔ The latest upstream changes (presumably #139012) made this pull request unmergeable. Please resolve the merge conflicts.

… r=<try> Ergonomic ref counting: optimize away clones when possible This PR build on top of rust-lang#134797. It optimizes codegen of ergonomic ref-counting when the type being `use`d is only known to be copy after monomorphization. We avoid codening a clone and generate bitwise copy instead. RFC: rust-lang/rfcs#3680 Tracking issue: rust-lang#132290 Project goal: rust-lang/rust-project-goals#107 r? `@nikomatsakis` This PR could better sit on top of rust-lang#131650 but as it did not land yet I've decided to just do minimal changes. It may be the case that doing what I'm doing regress the performance and we may need to go the full route of rust-lang#131650. cc `@saethlin` in this regard.

… r=nikomatsakis Ergonomic ref counting: optimize away clones when possible This PR build on top of rust-lang#134797. It optimizes codegen of ergonomic ref-counting when the type being `use`d is only known to be copy after monomorphization. We avoid codening a clone and generate bitwise copy instead. RFC: rust-lang/rfcs#3680 Tracking issue: rust-lang#132290 Project goal: rust-lang/rust-project-goals#107 r? `@nikomatsakis` This PR could better sit on top of rust-lang#131650 but as it did not land yet I've decided to just do minimal changes. It may be the case that doing what I'm doing regress the performance and we may need to go the full route of rust-lang#131650. cc `@saethlin` in this regard.

…tsakis Ergonomic ref counting: optimize away clones when possible This PR build on top of rust-lang/rust#134797. It optimizes codegen of ergonomic ref-counting when the type being `use`d is only known to be copy after monomorphization. We avoid codening a clone and generate bitwise copy instead. RFC: rust-lang/rfcs#3680 Tracking issue: rust-lang/rust#132290 Project goal: rust-lang/rust-project-goals#107 r? `@nikomatsakis` This PR could better sit on top of rust-lang/rust#131650 but as it did not land yet I've decided to just do minimal changes. It may be the case that doing what I'm doing regress the performance and we may need to go the full route of rust-lang/rust#131650. cc `@saethlin` in this regard.

bors · 2025-04-11T23:42:16Z

☔ The latest upstream changes (presumably #139689) made this pull request unmergeable. Please resolve the merge conflicts.

…tsakis Ergonomic ref counting: optimize away clones when possible This PR build on top of rust-lang/rust#134797. It optimizes codegen of ergonomic ref-counting when the type being `use`d is only known to be copy after monomorphization. We avoid codening a clone and generate bitwise copy instead. RFC: rust-lang/rfcs#3680 Tracking issue: rust-lang/rust#132290 Project goal: rust-lang/rust-project-goals#107 r? `@nikomatsakis` This PR could better sit on top of rust-lang/rust#131650 but as it did not land yet I've decided to just do minimal changes. It may be the case that doing what I'm doing regress the performance and we may need to go the full route of rust-lang/rust#131650. cc `@saethlin` in this regard.

bors · 2025-04-15T11:32:38Z

☔ The latest upstream changes (presumably #139845) made this pull request unmergeable. Please resolve the merge conflicts.

rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. labels Oct 13, 2024