Use as_deref in compiler (but only where it makes sense)

[WaffleLapkin]

This simplifies some code :3

(there are some changes that are not exacly as_deref, but more like "clever Option/Result method use")

[rustbot]

r? @wesleywiser

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

[rustbot]

Some changes occurred in compiler/rustc_codegen_cranelift

cc @bjorn3

[wesleywiser]

@bors try @rust-timer queue

[bors]

⌛ Trying commit 94470f4 with merge f86c17cdc363b12bc54a20fbff6b6e1a8744ec4d...

[bors]

☀️ Try build successful - checks-actions
Build commit: f86c17cdc363b12bc54a20fbff6b6e1a8744ec4d (f86c17cdc363b12bc54a20fbff6b6e1a8744ec4d)

[rust-timer]

Finished benchmarking commit (f86c17cdc363b12bc54a20fbff6b6e1a8744ec4d): 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.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-1.1%	[-1.1%, -1.1%]	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.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-2.3%	[-2.9%, -1.0%]	4
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.

	mean	range	count
Regressions ❌ (primary)	3.9%	[1.8%, 5.4%]	6
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	3.9%	[1.8%, 5.4%]	6

[WaffleLapkin]

The perf doesn't show any regressions (as expected, this doesn't really change anything). ctfe-stress-5 | {opt,debug} | incr-unchanged for some reason got ""significantly"" faster (Significance Factor ≈ 9x), looking at its history it looks legitimate, although surprising — I don't see anything here that could cause this. I think this is good to go.

[wesleywiser]

Thanks @WaffleLapkin!

@bors r+

[bors]

📌 Commit 94470f4 has been approved by wesleywiser

It is now in the queue for this repository.

[bors]

⌛ Testing commit 94470f4 with merge 872631d...

[bors]

☀️ Test successful - checks-actions
Approved by: wesleywiser
Pushing 872631d to master...

[rust-timer]

Finished benchmarking commit (872631d): comparison URL.

Overall result: no relevant changes - no action needed

@rustbot label: -perf-regression

Instruction count

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

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)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-3.0%	[-3.5%, -2.5%]	2
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.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	4.6%	[4.1%, 5.1%]	2
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0