Don't call temporary_scope twice.

[nnethercote]

mirror_expr_inner calls temporary_scope. It then calls make_mirror_unadjusted which makes an identical call to temporary_scope.

This commit changes the mirror_expr_inner to get the temp_lifetime out of the expression produced by make_mirror_unadjusted, similar to how it currently gets the type.

r? @cjgillot

[nnethercote]

@bors try @rust-timer queue

[bors]

⌛ Trying commit 6b9c412 with merge 77fbe01754d928b0abe469e83464bf87d78ab9d1...

[bors]

☀️ Try build successful - checks-actions
Build commit: 77fbe01754d928b0abe469e83464bf87d78ab9d1 (77fbe01754d928b0abe469e83464bf87d78ab9d1)

[rust-timer]

Finished benchmarking commit (77fbe01754d928b0abe469e83464bf87d78ab9d1): 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)	-0.3%	[-0.6%, -0.2%]	14
Improvements ✅ (secondary)	-0.9%	[-1.5%, -0.3%]	30
All ❌✅ (primary)	-0.3%	[-0.6%, -0.2%]	14

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)	0.9%	[0.7%, 1.0%]	3
Regressions ❌ (secondary)	1.4%	[1.4%, 1.4%]	1
Improvements ✅ (primary)	-2.9%	[-2.9%, -2.9%]	1
Improvements ✅ (secondary)	-2.5%	[-3.5%, -1.6%]	2
All ❌✅ (primary)	-0.0%	[-2.9%, 1.0%]	4

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)	-	-	0
Improvements ✅ (secondary)	-1.9%	[-2.3%, -1.3%]	4
All ❌✅ (primary)	-	-	0

[cjgillot]

That's unexpected for a 2 line change.
@bors r+

[bors]

📌 Commit 6b9c412 has been approved by cjgillot

It is now in the queue for this repository.

[bors]

🌲 The tree is currently closed for pull requests below priority 100. This pull request will be tested once the tree is reopened.

[nnethercote]

That's unexpected for a 2 line change.

I go where the profilers take me :)

[bors]

⌛ Testing commit 6b9c412 with merge b171953...

[bors]

☀️ Test successful - checks-actions
Approved by: cjgillot
Pushing b171953 to master...

[rust-timer]

Finished benchmarking commit (b171953): 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)	-0.3%	[-0.6%, -0.2%]	15
Improvements ✅ (secondary)	-1.0%	[-1.5%, -0.4%]	27
All ❌✅ (primary)	-0.3%	[-0.6%, -0.2%]	15

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)	-4.2%	[-4.2%, -4.2%]	1
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-4.2%	[-4.2%, -4.2%]	1

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)	-	-	0
Improvements ✅ (secondary)	-1.7%	[-2.0%, -1.4%]	2
All ❌✅ (primary)	-	-	0