[EXPERIMENT] Remove static booleans from rustc_query_impl::DynamicConfig

[Zalathar]

Checking the bootstrap-perf and compiler-perf implications of getting rid of the intermediate DynamicConfig layer.

r? ghost

[Zalathar]

@bors try @rust-timer queue

[rust-bors]

☀️ Try build successful (CI)
Build commit: 8ad1208 (8ad1208acfb04ec51735a52a806c87a481c22ef3, parent: 75963ce795666bc1f961e5d60060809809f6bc68)

[rust-timer]

Finished benchmarking commit (8ad1208): 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)	0.3%	[0.1%, 0.6%]	16
Regressions ❌ (secondary)	0.3%	[0.0%, 0.6%]	50
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.0%	[-0.1%, -0.0%]	3
All ❌✅ (primary)	0.3%	[0.1%, 0.6%]	16

Max RSS (memory usage)

Results (primary 2.7%, secondary -1.4%)

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

	mean	range	count
Regressions ❌ (primary)	2.7%	[2.7%, 2.7%]	1
Regressions ❌ (secondary)	2.4%	[1.3%, 5.4%]	6
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-5.2%	[-6.6%, -4.3%]	6
All ❌✅ (primary)	2.7%	[2.7%, 2.7%]	1

Cycles

Results (primary 2.6%, secondary -0.7%)

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

	mean	range	count
Regressions ❌ (primary)	2.6%	[2.6%, 2.6%]	1
Regressions ❌ (secondary)	3.0%	[2.1%, 5.0%]	4
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-4.3%	[-5.1%, -3.8%]	4
All ❌✅ (primary)	2.6%	[2.6%, 2.6%]	1

Binary size

Results (primary -0.0%, secondary -0.0%)

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)	-0.0%	[-0.0%, -0.0%]	4
Improvements ✅ (secondary)	-0.0%	[-0.0%, -0.0%]	1
All ❌✅ (primary)	-0.0%	[-0.0%, -0.0%]	4

Bootstrap: 471.746s -> 470.583s (-0.25%)
Artifact size: 383.60 MiB -> 385.85 MiB (0.59%)

[Zalathar]

Hmm, small but measurable regressions across the board.

[Zalathar]

I think my takeaway here is that we could afford to take this hit if we had a specific reason (e.g. unblocking other work), but general cleanup is perhaps not quite compelling enough on its own.

[petrochenkov]

@Zalathar
Nightly rustc supports using structs in const generics, so technically all the flags could be merged into one FLAGS parameter, perhaps that will look better than what we have now.

[Zalathar]

Oh nice.

I have a local branch where I tried to simulate const-generic structs using traits and macros, but being able to use an actual struct would be nicer.