2024-05-14 Triage Log

A pretty quiet week with only a few PRs being flagged for analysis. More improvements than regressions this week, and also several nice binary size reductions caused by generating less LLVM IR.

Triage done by @kobzol. Revision range: 69f53f5e..9105c57b

Summary:

(instructions:u)meanrangecount
Regressions ❌
(primary)		0.4%[0.2%, 0.9%]8
Regressions ❌
(secondary)		0.9%[0.2%, 2.4%]18
Improvements ✅
(primary)		-1.1%[-2.3%, -0.2%]51
Improvements ✅
(secondary)		-0.6%[-1.4%, -0.3%]19
All ❌✅ (primary)-0.9%[-2.3%, 0.9%]59

1 Regression, 0 Improvements, 3 Mixed; 0 of them in rollups 75 artifact comparisons made in total

Regressions

Do not add leading asterisk in the PartialEq #124157 (Comparison Link)

(instructions:u)meanrangecount
Regressions ❌
(primary)		0.3%[0.2%, 0.5%]9
Regressions ❌
(secondary)		0.4%[0.3%, 0.8%]9
Improvements ✅
(primary)		--0
Improvements ✅
(secondary)		--0
All ❌✅ (primary)0.3%[0.2%, 0.5%]9
  • Small regression on a few benchmarks caused by a change in code generation of #[derive(PartialEq)], which leads to more valid code being allowed to compile.
  • Marked as triaged.

Mixed

Avoid a cast in ptr::slice_from_raw_parts(_mut) #124795 (Comparison Link)

(instructions:u)meanrangecount
Regressions ❌
(primary)		0.3%[0.3%, 0.3%]1
Regressions ❌
(secondary)		--0
Improvements ✅
(primary)		-0.4%[-0.6%, -0.3%]6
Improvements ✅
(secondary)		-0.3%[-0.4%, -0.2%]16
All ❌✅ (primary)-0.3%[-0.6%, 0.3%]7
  • A single tiny regression outweighed by several performance wins.
  • This PR also reduced binary size nicely.

Avoid allocas in codegen for simple mir::Aggregate statements #123886 (Comparison Link)

(instructions:u)meanrangecount
Regressions ❌
(primary)		0.2%[0.2%, 0.3%]6
Regressions ❌
(secondary)		0.5%[0.2%, 1.3%]4
Improvements ✅
(primary)		-0.6%[-1.0%, -0.3%]6
Improvements ✅
(secondary)		-0.7%[-1.1%, -0.4%]2
All ❌✅ (primary)-0.2%[-1.0%, 0.3%]12
  • The regression was limited to a single primary benchmark, there were more primary benchmark wins.
  • Also a nice binary size reduction in debug builds.

Remove NtIdent and NtLifetime #124256 (Comparison Link)

(instructions:u)meanrangecount
Regressions ❌
(primary)		0.2%[0.2%, 0.2%]1
Regressions ❌
(secondary)		1.9%[1.2%, 2.7%]8
Improvements ✅
(primary)		-0.8%[-2.0%, -0.1%]24
Improvements ✅
(secondary)		-0.6%[-1.1%, -0.3%]9
All ❌✅ (primary)-0.7%[-2.0%, 0.2%]25
  • Pretty much a pure performance improvement, the instruction count regression on tt-muncher was actually a decent win in cycle count.