[perf] Use Blake2 for the type-id hash

[Urgau]

and only for the TypeId hash, not as a general stable hasher.

cc @michaelwoerister

[Urgau]

@bors try @rust-timer queue

[bors]

⌛ Trying commit 541f409 with merge cf164ca...

[bors]

💔 Test failed - checks-actions

[Urgau]

@bors try

[bors]

⌛ Trying commit 28b8ba4 with merge 12daf8a...

[bors]

💔 Test failed - checks-actions

[bjorn3]

I am pretty sure you can just use Fingerprint(p0, p1). Blake2s is proven to be indistinguishable from a random function according to https://eprint.iacr.org/2016/827. If a prefix of the hash was biased, it wouldn't be indistinguishable from a random function. Because of the lack of bias on the low bytes, there is no need to mix in the high bytes.

[Urgau]

@bors try @rust-timer queue

[bors]

⌛ Trying commit a42b030 with merge 3a79c24...

[bors]

☀️ Try build successful - checks-actions
Build commit: 3a79c24 (3a79c247d7abef9e66f5f689fe7c7ffc16716f11)

[rust-timer]

Finished benchmarking commit (3a79c24): comparison URL.

Overall result: ❌ regressions - BENCHMARK(S) FAILED

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

❗ ❗ ❗ ❗ ❗
Warning ⚠️: The following benchmark(s) failed to build:

• regression-31157
• issue-88862
• serde-1.0.136

❗ ❗ ❗ ❗ ❗

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
Regressions ❌ (secondary)	0.5%	[0.5%, 0.5%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Max RSS (memory usage)

Results (primary 5.3%, secondary -3.3%)

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)	5.3%	[5.3%, 5.3%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-3.3%	[-3.6%, -3.0%]	2
All ❌✅ (primary)	5.3%	[5.3%, 5.3%]	1

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: 751.515s -> 753.185s (0.22%)
Artifact size: 339.18 MiB -> 339.18 MiB (0.00%)

[Urgau]

@bors try @rust-timer queue

[bors]

⌛ Trying commit 41990be with merge c2fdbf6...

[michaelwoerister]

@Urgau, before you invest too much time in this: I think it is preferable to go through (a possibly adapted version of) v0 mangling for type-id (and then potentially cryptographically hash that if constant space for type-ids is desirable).

[bors]

☀️ Try build successful - checks-actions
Build commit: c2fdbf6 (c2fdbf6168ca1643684ba55c29e874cfcb9170a9)

[rust-timer]

Finished benchmarking commit (c2fdbf6): 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
Regressions ❌ (secondary)	0.6%	[0.6%, 0.6%]	1
Improvements ✅ (primary)	-0.2%	[-0.2%, -0.2%]	2
Improvements ✅ (secondary)	-0.2%	[-0.3%, -0.2%]	5
All ❌✅ (primary)	-0.2%	[-0.2%, -0.2%]	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: 751.027s -> 754.153s (0.42%)
Artifact size: 339.18 MiB -> 339.20 MiB (0.01%)