Reduce some queries around associated items

[camsteffen]

No description provided.

[rustbot]

r? @petrochenkov

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[rustbot]

Some changes occurred to the CTFE machinery

cc @RalfJung, @oli-obk, @lcnr

Some changes occurred to MIR optimizations

cc @rust-lang/wg-mir-opt

Some changes occurred to the CTFE / Miri interpreter

cc @rust-lang/miri

[petrochenkov]

@bors2 try @rust-timer queue

[rust-bors]

☀️ Try build successful (CI)
Build commit: 811ef38 (811ef38822ea064db8fdb0a434857b88b1a36cd3, parent: fce0e74720d199eb7839fdb51af35ac5226da178)

[rust-timer]

Finished benchmarking commit (811ef38): comparison URL.

Overall result: no relevant changes - no action needed

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.

@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 -2.2%)

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
Improvements ✅ (secondary)	-2.2%	[-2.2%, -2.2%]	1
All ❌✅ (primary)	-	-	0

Cycles

Results (primary 2.5%, secondary 8.9%)

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

	mean	range	count
Regressions ❌ (primary)	2.5%	[2.5%, 2.5%]	1
Regressions ❌ (secondary)	8.9%	[6.1%, 11.6%]	2
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	2.5%	[2.5%, 2.5%]	1

Binary size

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

Bootstrap: 464.993s -> 464.719s (-0.06%)
Artifact size: 377.36 MiB -> 377.36 MiB (0.00%)

[oli-obk]

Cache hits of the def_kind and impl_trait_header have been reduced. No otherwise measurable impact, but it usually takes several changes like this to positively affect perf

[petrochenkov]

There are two kinds of changes here:

• the changes that simplify code - these are good
• the changes that do not simplify code, but should be optimizations in theory, but are not noticeable in practice - I'm not sure we should merge those

Although it looks like we can optimize some primitives here, making the code both simpler and more micro-optimized, let me write some inline comments.

[petrochenkov]

Although it looks like we can optimize some primitives here

Hm, actually not, the def kind checks are not redundant, some are on the def-id itself, and some are on its parent.

[petrochenkov]

I think this would benefit from

• a version of assoc_parent returning DefKind in addition to DefId,
• maybe also having trait_impl_of_assoc/inherent_impl_of_assoc in addition to just impl_of_assoc,
• removing micro-optimizations that do not fit into the pattern above ^^^ and hand roll some logic just to save a call to def_kind

@rustbot author

[rustbot]

Reminder, once the PR becomes ready for a review, use @rustbot ready.

[camsteffen]

I went with all of your ideas and I think it looks nice! @rustbot ready

[petrochenkov]

Doesn't look like an improvement.

[petrochenkov]

r=me with #145266 (comment) addressed.
@bors rollup=maybe