More aggressive CGU merging

[nnethercote]

r? @ghost

[nnethercote]

@bors try @rust-timer queue

[bors]

⌛ Trying commit e8379a7 with merge fd8020ccffcc7d3cc03bce0b231f6b50a8f866e3...

[bors]

☀️ Try build successful - checks-actions
Build commit: fd8020ccffcc7d3cc03bce0b231f6b50a8f866e3 (fd8020ccffcc7d3cc03bce0b231f6b50a8f866e3)

[rust-timer]

Finished benchmarking commit (fd8020ccffcc7d3cc03bce0b231f6b50a8f866e3): comparison URL.

Overall result: ❌✅ regressions and improvements - 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.

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 a highly reliable metric that was used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	0.5%	[0.2%, 1.8%]	115
Regressions ❌ (secondary)	0.7%	[0.2%, 2.4%]	64
Improvements ✅ (primary)	-1.3%	[-4.5%, -0.3%]	16
Improvements ✅ (secondary)	-0.9%	[-3.2%, -0.2%]	7
All ❌✅ (primary)	0.3%	[-4.5%, 1.8%]	131

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)	7.2%	[2.9%, 13.8%]	10
Regressions ❌ (secondary)	2.0%	[1.4%, 2.5%]	2
Improvements ✅ (primary)	-4.7%	[-14.3%, -1.6%]	5
Improvements ✅ (secondary)	-2.7%	[-4.0%, -1.3%]	5
All ❌✅ (primary)	3.2%	[-14.3%, 13.8%]	15

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)	2.2%	[2.2%, 2.2%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-2.7%	[-5.0%, -1.3%]	6
Improvements ✅ (secondary)	-4.2%	[-4.2%, -4.2%]	1
All ❌✅ (primary)	-2.0%	[-5.0%, 2.2%]	7

Binary size

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)	0.1%	[0.0%, 0.4%]	10
Regressions ❌ (secondary)	1.0%	[1.0%, 1.0%]	1
Improvements ✅ (primary)	-1.4%	[-8.1%, -0.0%]	38
Improvements ✅ (secondary)	-3.4%	[-13.3%, -0.2%]	7
All ❌✅ (primary)	-1.1%	[-8.1%, 0.4%]	48

Bootstrap: 647.125s -> 648.507s (0.21%)

[nnethercote]

Inaccurate CGU size estimates mean this idea is very hard to get working well, alas.