Only visit reachable blocks in ConstProp lint.

[cjgillot]

Fixes #78803
Fixes #109731

[rustbot]

r? @compiler-errors

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

[rustbot]

Some changes occurred to MIR optimizations

cc @rust-lang/wg-mir-opt

[Noratrieb]

Does this also fix #78803?

[cjgillot]

Yes, added a test.

[bors]

☔ The latest upstream changes (presumably #109819) made this pull request unmergeable. Please resolve the merge conflicts.

[cjgillot]

Just in case:
@bors try @rust-timer queue

[bors]

⌛ Trying commit 2de1e0d360eaffa73ff7e4aa91c2582807771d38 with merge 0e11821993d7df722968873d7817efa9ad6a1f1d...

[bors]

☀️ Try build successful - checks-actions
Build commit: 0e11821993d7df722968873d7817efa9ad6a1f1d (0e11821993d7df722968873d7817efa9ad6a1f1d)

[bors]

☀️ Try build successful - checks-actions
Build commit: 0e11821993d7df722968873d7817efa9ad6a1f1d (0e11821993d7df722968873d7817efa9ad6a1f1d)

[rust-timer]

Finished benchmarking commit (0e11821993d7df722968873d7817efa9ad6a1f1d): 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
Improvements ✅ (secondary)	-0.3%	[-0.3%, -0.3%]	1
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)	3.2%	[3.2%, 3.2%]	1
Regressions ❌ (secondary)	1.3%	[1.3%, 1.3%]	2
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	3.2%	[3.2%, 3.2%]	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)	1.4%	[1.4%, 1.4%]	1
Improvements ✅ (primary)	-2.8%	[-4.6%, -0.5%]	10
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-2.8%	[-4.6%, -0.5%]	10

[oli-obk]

r=me after a rebase

[cjgillot]

@bors r=oli-obk

[bors]

📌 Commit 98255cc has been approved by oli-obk

It is now in the queue for this repository.

[bors]

⌛ Testing commit 98255cc with merge f211da7...

[bors]

☀️ Test successful - checks-actions
Approved by: oli-obk
Pushing f211da7 to master...

[rust-timer]

Finished benchmarking commit (f211da7): 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)	3.9%	[3.9%, 3.9%]	1
Regressions ❌ (secondary)	2.6%	[2.6%, 2.6%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-1.8%	[-2.2%, -1.4%]	2
All ❌✅ (primary)	3.9%	[3.9%, 3.9%]	1

Cycles

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

[apiraino]

Going to nominate for a backport because one issue fixed is a P-high

@rustbot label +beta-nominated

[apiraino]

Beta backport accepted as per compiler team on Zulip

@rustbot label +beta-accepted

[apiraino]

this was not fixing a beta regression (my bad for misunderstanding the context)

@rustbot label -beta-accepted -beta-nominated