Revert "Remove deferred sized checks"

[compiler-errors]

cc: #100652 (comment)

I'm okay with reverting this for now, and I will look into the diagnostic regressions.

This reverts commit 33212bf.

r? @pnkfelix

---

EDIT: This also fixes #101066, a regression in method selection logic/coercion(?) due to the early registering of a Sized bound.

[compiler-errors]

@bors try @rust-timer queue

[rust-timer]

Awaiting bors try build completion.

@rustbot label: +S-waiting-on-perf

[bors]

⌛ Trying commit 4cda07276706f5fe9ac717e0bc3d910d3f09b2c4 with merge dda8534232f54934ab4d3d5a3b59689254fdeb05...

[bors]

☀️ Try build successful - checks-actions
Build commit: dda8534232f54934ab4d3d5a3b59689254fdeb05 (dda8534232f54934ab4d3d5a3b59689254fdeb05)

[rust-timer]

Queued dda8534232f54934ab4d3d5a3b59689254fdeb05 with parent 4a24f08, future comparison URL.

[rust-timer]

Finished benchmarking commit (dda8534232f54934ab4d3d5a3b59689254fdeb05): 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-review -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.

	mean1	range	count2
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-1.7%	[-1.8%, -1.6%]	2
All ❌✅ (primary)	-	-	0

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.

	mean1	range	count2
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	3.9%	[2.8%, 5.1%]	2
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

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.

	mean1	range	count2
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	2.7%	[2.7%, 2.7%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Footnotes

1. the arithmetic mean of the percent change ↩ ↩² ↩³

2. number of relevant changes ↩ ↩² ↩³

[compiler-errors]

Hm, why would it be that reverting this PR doesn't cause a perf improvement (at least for the primary regressions seen in that rollup, like serde).

[compiler-errors]

ping @pnkfelix, originally opened this as a revert due to the perf regression (which is why i r?'ed you), but turns out it's also a typechecker regression, so this is a pretty easy r+

[pnkfelix]

@bors r+

[bors]

📌 Commit eda91d9 has been approved by pnkfelix

It is now in the queue for this repository.

[bors]

⌛ Testing commit eda91d9 with merge 0209485...

[bors]

☀️ Test successful - checks-actions
Approved by: pnkfelix
Pushing 0209485 to master...

[rust-timer]

Finished benchmarking commit (0209485): comparison URL.

Overall result: ❌✅ regressions and improvements - ACTION NEEDED

Next Steps: If you can justify the regressions found in this perf run, please indicate this with @rustbot label: +perf-regression-triaged along with sufficient written justification. If you cannot justify the regressions please open an issue or create a new PR that fixes the regressions, add a comment linking to the newly created issue or PR, and then add the perf-regression-triaged label to this PR.

@rustbot label: +perf-regression
cc @rust-lang/wg-compiler-performance

Instruction count

This is a highly reliable metric that was used to determine the overall result at the top of this comment.

	mean1	range	count2
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	0.9%	[0.6%, 2.4%]	7
Improvements ✅ (primary)	-1.2%	[-1.3%, -1.1%]	2
Improvements ✅ (secondary)	-1.7%	[-1.7%, -1.6%]	2
All ❌✅ (primary)	-1.2%	[-1.3%, -1.1%]	2

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.

	mean1	range	count2
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	5.8%	[2.0%, 8.3%]	4
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-3.4%	[-4.2%, -2.5%]	3
All ❌✅ (primary)	-	-	0

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.

	mean1	range	count2
Regressions ❌ (primary)	2.0%	[2.0%, 2.0%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-3.3%	[-3.3%, -3.3%]	1
Improvements ✅ (secondary)	-2.4%	[-2.4%, -2.4%]	1
All ❌✅ (primary)	-0.6%	[-3.3%, 2.0%]	2

Footnotes

1. the arithmetic mean of the percent change ↩ ↩² ↩³

2. number of relevant changes ↩ ↩² ↩³

[compiler-errors]

I am dumbfounded. This PR was opened because of a perf regression, then tested neutrally, then turned into a regression.

[nnethercote]

The supposed regressions are mostly in keccak, which has been noisy lately. Pretty sure those changes are just noise, and this is actually perf-neutral.

@rustbot label: +perf-regression-triaged