proc_macro bridge fxhash perf testing

[lukas-code]

results:

• updating to rustc-hash v2: no changes: proc_macro bridge fxhash perf testing #134434 (comment)
• replacing it with the default hasher: minor regression in a stress test: proc_macro bridge fxhash perf testing #134434 (comment)

[lukas-code]

@bors try @rust-timer queue

[bors]

⌛ Trying commit 51749d0 with merge 0511dbb...

[bors]

☀️ Try build successful - checks-actions
Build commit: 0511dbb (0511dbb04f6ebaa3f562d4a50ac346f618923a5a)

[rust-timer]

Finished benchmarking commit (0511dbb): comparison URL.

Overall result: no relevant changes - no 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.

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

Instruction count

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

Max RSS (memory usage)

Results (secondary -3.4%)

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
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-3.4%	[-4.6%, -2.3%]	2
All ❌✅ (primary)	-	-	0

Cycles

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

Binary size

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

Bootstrap: 770.185s -> 770.679s (0.06%)
Artifact size: 330.28 MiB -> 330.35 MiB (0.02%)

[lukas-code]

hmm, no changes at at all. let's see if we can just use the default hasher then: @bors try @rust-timer queue

[bors]

⌛ Trying commit 49843b2 with merge 66534ef...

[bors]

☀️ Try build successful - checks-actions
Build commit: 66534ef (66534ef0b4abdb0b10612fc66c0dd17f03e62688)

[rust-timer]

Finished benchmarking commit (66534ef): comparison URL.

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

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 the most reliable metric that we have; it was used to determine the overall result at the top of this comment. However, even this metric can sometimes exhibit noise.

	mean	range	count
Regressions ❌ (primary)	0.3%	[0.2%, 0.3%]	2
Regressions ❌ (secondary)	1.0%	[0.5%, 1.6%]	8
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.3%	[-0.3%, -0.3%]	1
All ❌✅ (primary)	0.3%	[0.2%, 0.3%]	2

Max RSS (memory usage)

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

Cycles

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

Binary size

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

Bootstrap: 769.242s -> 769.828s (0.08%)
Artifact size: 330.31 MiB -> 330.32 MiB (0.00%)

[tgross35]

I wonder if the perf suite just isn't exercising proc macros very much. Using the builtin HashMap would be a nice cleanup if there aren't any significant regressions.

[lukas-code]

I was just about to close, but if you want to keep this, then r? @tgross35 i guess

[tgross35]

Well, the regressions aren't huge but probably enough that removing ~100 LOC isn't worth it. I guess you can close this if that was what you intended.

[lukas-code]

Alright, closing then.