Make lowering incremental, take 3/N

[cjgillot]

Rebase of #88186 that was rebased by #127262

No real change in design, so I'm not expecting a perf miracle.

r? @ghost

[cjgillot]

@bors try @rust-timer queue

[bors]

⌛ Trying commit 0e2f90b with merge a6b131d...

[bors]

☀️ Try build successful - checks-actions
Build commit: a6b131d (a6b131d42573c085b032a153779366b448148b9d)

[rust-timer]

Finished benchmarking commit (a6b131d): comparison URL.

Overall result: ❌✅ regressions and improvements - please read the text below

Benchmarking this pull request means it may be perf-sensitive – we'll automatically label it not fit for rolling up. You can override this, but we strongly advise not to, due to possible changes in compiler perf.

Next Steps: If you can justify the regressions found in this try perf run, please do so in sufficient writing along with @rustbot label: +perf-regression-triaged. If not, please fix the regressions and do another perf run. If its results are neutral or positive, the label will be automatically removed.

@bors rollup=never
@rustbot label: -S-waiting-on-perf +perf-regression

Instruction count

Our most reliable metric. Used to determine the overall result above. However, even this metric can be noisy.

	mean	range	count
Regressions ❌ (primary)	0.8%	[0.2%, 1.8%]	157
Regressions ❌ (secondary)	1.1%	[0.2%, 4.3%]	69
Improvements ✅ (primary)	-0.4%	[-0.5%, -0.3%]	5
Improvements ✅ (secondary)	-0.3%	[-0.5%, -0.2%]	7
All ❌✅ (primary)	0.7%	[-0.5%, 1.8%]	162

Max RSS (memory usage)

Results (primary 10.5%, secondary 10.1%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	10.5%	[3.1%, 28.6%]	249
Regressions ❌ (secondary)	10.1%	[2.2%, 31.4%]	142
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	10.5%	[3.1%, 28.6%]	249

Cycles

Results (primary 2.5%, secondary 4.1%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	2.5%	[1.4%, 5.5%]	35
Regressions ❌ (secondary)	4.1%	[1.8%, 7.5%]	22
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	2.5%	[1.4%, 5.5%]	35

Binary size

Results (primary -0.1%, secondary -0.2%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-0.1%	[-0.2%, -0.0%]	82
Improvements ✅ (secondary)	-0.2%	[-0.9%, -0.0%]	43
All ❌✅ (primary)	-0.1%	[-0.2%, -0.0%]	82

Bootstrap: 690.042s -> 689.298s (-0.11%)
Artifact size: 371.86 MiB -> 371.81 MiB (-0.01%)

[cjgillot]

@bors try @rust-timer queue

[bors]

⌛ Trying commit 8ab4e63 with merge 31325ff...

[bors]

☀️ Try build successful - checks-actions
Build commit: 31325ff (31325ff312ad91d8a2dd156c832cacc0435f9ea1)

[rust-timer]

Finished benchmarking commit (31325ff): comparison URL.

Overall result: ❌✅ regressions and improvements - please read the text below

Benchmarking this pull request means it may be perf-sensitive – we'll automatically label it not fit for rolling up. You can override this, but we strongly advise not to, due to possible changes in compiler perf.

Next Steps: If you can justify the regressions found in this try perf run, please do so in sufficient writing along with @rustbot label: +perf-regression-triaged. If not, please fix the regressions and do another perf run. If its results are neutral or positive, the label will be automatically removed.

@bors rollup=never
@rustbot label: -S-waiting-on-perf +perf-regression

Instruction count

Our most reliable metric. Used to determine the overall result above. However, even this metric can be noisy.

	mean	range	count
Regressions ❌ (primary)	0.5%	[0.2%, 1.3%]	120
Regressions ❌ (secondary)	0.8%	[0.2%, 3.2%]	77
Improvements ✅ (primary)	-0.7%	[-1.3%, -0.2%]	12
Improvements ✅ (secondary)	-0.6%	[-1.3%, -0.2%]	37
All ❌✅ (primary)	0.4%	[-1.3%, 1.3%]	132

Max RSS (memory usage)

Results (primary 10.8%, secondary 10.4%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	10.8%	[2.3%, 29.1%]	248
Regressions ❌ (secondary)	10.4%	[1.9%, 31.7%]	143
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	10.8%	[2.3%, 29.1%]	248

Cycles

Results (primary 2.1%, secondary 4.1%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	2.1%	[1.2%, 3.8%]	20
Regressions ❌ (secondary)	4.1%	[1.7%, 6.6%]	16
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	2.1%	[1.2%, 3.8%]	20

Binary size

Results (primary -0.1%, secondary -0.2%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-0.1%	[-0.2%, -0.0%]	83
Improvements ✅ (secondary)	-0.2%	[-0.9%, -0.0%]	43
All ❌✅ (primary)	-0.1%	[-0.2%, -0.0%]	83

Bootstrap: 689.082s -> 688.79s (-0.04%)
Artifact size: 371.89 MiB -> 371.87 MiB (-0.00%)