2023-04-25 Triage Log

A week mostly dominated by noise, in particular a persistent bimodality in keccak and cranelift-codegen. No significant changes outside of that, a relatively equal mix of regressions and improvements. Most of the bimodality has been removed below as it's just noise.

Triage done by @simulacrum. Revision range: 74864fa496997a6498e623f0d2019ccb7eb6dad0..fdeef3ed1809aa9bd4ea9ff0fad92010c6de669c

Summary:

(instructions:u)	mean	range	count
Regressions ❌ (primary)	1.2%	[0.5%, 2.2%]	11
Regressions ❌ (secondary)	2.0%	[0.6%, 7.7%]	48
Improvements ✅ (primary)	-1.0%	[-3.6%, -0.3%]	144
Improvements ✅ (secondary)	-1.6%	[-6.7%, -0.3%]	89
All ❌✅ (primary)	-0.9%	[-3.6%, 2.2%]	155

3 Regressions, 6 Improvements, 5 Mixed; 1 of them in rollups 60 artifact comparisons made in total

Regressions

Support AIX-style archive type #106704 (Comparison Link)

(instructions:u)	mean	range	count
Regressions ❌ (primary)	1.1%	[1.0%, 1.2%]	6
Regressions ❌ (secondary)	2.5%	[1.1%, 3.9%]	2
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	1.1%	[1.0%, 1.2%]	6

This PR also bumped std dependencies, which likely explains the additional compile time cost in our smallest benchmarks (e.g., helloworld).

Ensure mir_drops_elaborated_and_const_checked when requiring codegen. #110107 (Comparison Link)

(instructions:u)	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	2.0%	[1.7%, 2.4%]	10
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Per comment on the PR this is enabling lints to run on dead code, expected regression.

Encode lifetime param spans too #110469 (Comparison Link)

(instructions:u)	mean	range	count
Regressions ❌ (primary)	0.5%	[0.2%, 0.7%]	21
Regressions ❌ (secondary)	0.7%	[0.3%, 0.9%]	4
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.5%	[0.2%, 0.7%]	21

This comment justifies the regressions.

Improvements

Don't allocate on SimplifyCfg/Locals/Const on every MIR pass #110477 (Comparison Link)

(instructions:u)	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-0.5%	[-0.7%, -0.3%]	10
Improvements ✅ (secondary)	-0.6%	[-0.7%, -0.4%]	9
All ❌✅ (primary)	-0.5%	[-0.7%, -0.3%]	10

Rm const traits in libcore #110393 (Comparison Link)

(instructions:u)	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-0.9%	[-2.6%, -0.4%]	15
Improvements ✅ (secondary)	-1.7%	[-2.8%, -0.5%]	24
All ❌✅ (primary)	-0.9%	[-2.6%, -0.4%]	15

In LexicalResolver, don't construct graph unless necessary. #110527 (Comparison Link)

(instructions:u)	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-0.3%	[-0.4%, -0.2%]	4
Improvements ✅ (secondary)	-0.4%	[-0.8%, -0.2%]	11
All ❌✅ (primary)	-0.3%	[-0.4%, -0.2%]	4

Enable flatten-format-args by default. #109999 (Comparison Link)

(instructions:u)	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-1.5%	[-2.3%, -0.6%]	10
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-1.5%	[-2.3%, -0.6%]	10

Allow to feed a value in another query's cache and remove WithOptConstParam #96840 (Comparison Link)

(instructions:u)	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	0.6%	[0.6%, 0.6%]	1
Improvements ✅ (primary)	-0.8%	[-2.1%, -0.3%]	57
Improvements ✅ (secondary)	-0.9%	[-1.7%, -0.3%]	26
All ❌✅ (primary)	-0.8%	[-2.1%, -0.3%]	57

Report allocation errors as panics #109507 (Comparison Link)

(instructions:u)	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-0.2%	[-0.2%, -0.2%]	3
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-0.2%	[-0.2%, -0.2%]	3

Mixed

rustc_metadata: Remove Span from ModChild #109772 (Comparison Link)

(instructions:u)	mean	range	count
Regressions ❌ (primary)	0.4%	[0.3%, 0.5%]	5
Regressions ❌ (secondary)	0.2%	[0.2%, 0.2%]	1
Improvements ✅ (primary)	-0.4%	[-0.7%, -0.2%]	15
Improvements ✅ (secondary)	-1.4%	[-4.2%, -0.4%]	13
All ❌✅ (primary)	-0.2%	[-0.7%, 0.5%]	20

Rollup of 10 pull requests #110546 (Comparison Link)

(instructions:u)	mean	range	count
Regressions ❌ (primary)	1.6%	[1.1%, 2.1%]	3
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-3.1%	[-3.1%, -3.1%]	1
All ❌✅ (primary)	1.6%	[1.1%, 2.1%]	3

resolve: Remove module_children_untracked #110542 (Comparison Link)

(instructions:u)	mean	range	count
Regressions ❌ (primary)	0.6%	[0.2%, 0.9%]	11
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-0.3%	[-0.3%, -0.3%]	1
Improvements ✅ (secondary)	-1.5%	[-1.9%, -1.0%]	3
All ❌✅ (primary)	0.6%	[-0.3%, 0.9%]	12

Turn on ConstDebugInfo pass. #107404 (Comparison Link)

(instructions:u)	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

Remove the size of locals heuristic in MIR inlining #110705 (Comparison Link)

(instructions:u)	mean	range	count
Regressions ❌ (primary)	0.9%	[0.3%, 2.7%]	9
Regressions ❌ (secondary)	1.9%	[0.3%, 7.9%]	34
Improvements ✅ (primary)	-0.6%	[-1.8%, -0.2%]	59
Improvements ✅ (secondary)	-0.8%	[-2.5%, -0.2%]	46
All ❌✅ (primary)	-0.4%	[-1.8%, 2.7%]	68