[EXPERIMENT] Change query erase_and_anonymize_regions_ty from anon to no_hash

[Zalathar]

Based on its comment, this query's use of anon might be better off as no_hash.

• Zulip thread
• PR that made this query anon: make erase_regions_ty query anonymous #45364

r? ghost

[Zalathar]

@bors try @rust-timer queue

[rust-bors]

☀️ Try build successful (CI)
Build commit: b9ba9d8 (b9ba9d8b24db14e463473daf7c51084a1a4c435b, parent: c58d9f9f82ead734d73d99a64e910718f5f464d3)

[rust-timer]

Finished benchmarking commit (b9ba9d8): 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%	[0.2%, 0.3%]	3
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.2%	[-0.2%, -0.1%]	3
All ❌✅ (primary)	0.3%	[0.2%, 0.3%]	3

Max RSS (memory usage)

Results (primary 0.4%, secondary 2.3%)

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

	mean	range	count
Regressions ❌ (primary)	0.4%	[0.4%, 0.4%]	1
Regressions ❌ (secondary)	2.3%	[2.3%, 2.3%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.4%	[0.4%, 0.4%]	1

Cycles

Results (secondary 3.9%)

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)	3.9%	[3.9%, 3.9%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Binary size

This benchmark run did not return any relevant results for this metric.

Bootstrap: 475.659s -> 474.598s (-0.22%)
Artifact size: 398.00 MiB -> 397.98 MiB (-0.01%)

[Zalathar]

Hmm, there's a small but measurable regression in cargo, backed up by an increased call count for incr_comp_encode_dep_graph.

We could conceivably eat the loss if we had sufficient motivation (e.g. getting rid of anon entirely), but for now the single extra anon isn't doing much harm.