fast path for declared_generic_bounds_from_env

[aliemjay]

~2% perf gain for diesel

[rustbot]

r? @b-naber

(rustbot has picked a reviewer for you, use r? to override)

[aliemjay]

@bors try @rust-timer queue

[bors]

⌛ Trying commit 20e222a with merge e0a7b59...

[compiler-errors]

r=me after perf

[aliemjay]

Suggested change

	(ty::Alias(_, a1), GenericKind::Alias(a2)) if a1.def_id != a2.def_id => {
	return None;
	}
	(ty::Param(p1), GenericKind::Param(p2)) if p1 != p2 => return None,
	_ => {}
	(ty::Alias(_, a1), GenericKind::Alias(a2)) if a1.def_id == a2.def_id =>{}
	(ty::Param(p1), GenericKind::Param(p2)) if p1 == p2 => {}
	_ => return None,

This should cover more cases.

[aliemjay]

This is missing the case of GenericKind::Placeholder.

[bors]

☀️ Try build successful - checks-actions
Build commit: e0a7b59 (e0a7b59fd81315e056574a0f8fb51546821d3753)

[rust-timer]

Finished benchmarking commit (e0a7b59): comparison URL.

Overall result: ✅ improvements - 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 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
Improvements ✅ (primary)	-1.4%	[-2.2%, -0.2%]	8
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-1.4%	[-2.2%, -0.2%]	8

Max RSS (memory usage)

Results

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)	0.5%	[0.5%, 0.5%]	1
Regressions ❌ (secondary)	1.3%	[1.3%, 1.4%]	2
Improvements ✅ (primary)	-0.5%	[-0.5%, -0.5%]	1
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-0.0%	[-0.5%, 0.5%]	2

Cycles

Results

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)	0.6%	[0.4%, 0.7%]	4
Regressions ❌ (secondary)	2.1%	[1.6%, 2.5%]	5
Improvements ✅ (primary)	-1.3%	[-1.5%, -1.1%]	2
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-0.1%	[-1.5%, 0.7%]	6

Binary size

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

Bootstrap: 673.256s -> 671.287s (-0.29%)
Artifact size: 312.47 MiB -> 312.47 MiB (0.00%)

[compiler-errors]

@rustbot author

[aliemjay]

Added a comment about rigid alias types and implemented an alternative approach

@rustbot review

[compiler-errors]

r=me

[aliemjay]

@bors r=compiler-errors rollup=never

[bors]

📌 Commit 27e964d has been approved by compiler-errors

It is now in the queue for this repository.

[bors]

⌛ Testing commit 27e964d with merge 57ad505...

[bors]

☀️ Test successful - checks-actions
Approved by: compiler-errors
Pushing 57ad505 to master...

[nnethercote]

@aliemjay: how did you find this improvement? Profiling, looking through the code, something else? I'm curious :)

[rust-timer]

Finished benchmarking commit (57ad505): comparison URL.

Overall result: ✅ improvements - no action needed

@rustbot label: -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
Improvements ✅ (primary)	-1.9%	[-2.9%, -0.2%]	8
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-1.9%	[-2.9%, -0.2%]	8

Max RSS (memory usage)

Results

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)	3.5%	[3.5%, 3.5%]	1
Improvements ✅ (primary)	-0.6%	[-0.6%, -0.5%]	2
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-0.6%	[-0.6%, -0.5%]	2

Cycles

Results

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)	-1.7%	[-1.8%, -1.5%]	4
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-1.7%	[-1.8%, -1.5%]	4

Binary size

Results

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)	0.0%	[0.0%, 0.0%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Bootstrap: 673.86s -> 671.988s (-0.28%)
Artifact size: 312.43 MiB -> 312.43 MiB (0.00%)

[aliemjay]

@aliemjay: how did you find this improvement? Profiling, looking through the code, something else? I'm curious :)

by callgrind profiles, looking at code that I have some expertise in so that I can easily catch optimazation opportunities.