Optimize mk_region

[nnethercote]

PR #107869 avoiding some interning under mk_ty by special-casing Ty variants with simple (integer) bodies. This PR does something similar for regions.

r? @compiler-errors

[rustbot]

Some changes occurred to MIR optimizations

cc @rust-lang/wg-mir-opt

[compiler-errors]

r=me when perf comes back green, looks good to me.

edit: oh, also seems to need a rebase.

[nnethercote]

Thanks for the fast review!

@bors try @rust-timer queue

[bors]

⌛ Trying commit a6d704eb87efb0a15e1d6b49ab44a8088ae5576f with merge 87ab11387193414f9cbceff868dd2f1f59f60803...

[bors]

☀️ Try build successful - checks-actions
Build commit: 87ab11387193414f9cbceff868dd2f1f59f60803 (87ab11387193414f9cbceff868dd2f1f59f60803)

[nnethercote]

BTW, I tried similar things with mk_predicate, but predicates are more complex. There are no variants containing just an integer, for example. The existing reuse_or_mk_predicate function is effective, I couldn't improve on that.

[rust-timer]

Finished benchmarking commit (87ab11387193414f9cbceff868dd2f1f59f60803): 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%	[-0.3%, -0.3%]	1
Improvements ✅ (secondary)	-0.4%	[-0.4%, -0.4%]	2
All ❌✅ (primary)	-0.3%	[-0.3%, -0.3%]	1

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)	0.6%	[0.6%, 0.6%]	1
Regressions ❌ (secondary)	2.1%	[1.8%, 3.1%]	4
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-1.6%	[-2.1%, -0.7%]	5
All ❌✅ (primary)	0.6%	[0.6%, 0.6%]	1

Cycles

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

[oli-obk]

@bors r=compiler-errors

[bors]

📌 Commit a6d704eb87efb0a15e1d6b49ab44a8088ae5576f has been approved by compiler-errors

It is now in the queue for this repository.

[bors]

☔ The latest upstream changes (presumably #108052) made this pull request unmergeable. Please resolve the merge conflicts.

[nnethercote]

I rebased.

@bors r=compiler-errors

[bors]

📌 Commit 9a53cee has been approved by compiler-errors

It is now in the queue for this repository.

[compiler-errors]

@bors retry

[rust-log-analyzer]

The job mingw-check failed! Check out the build log: (web) (plain)

Click to see the possible cause of the failure (guessed by this bot)

curl: (22) The requested URL returned error: 404

error: failed to download llvm from ci

    help: old builds get deleted after a certain time
    help: if trying to compile an old commit of rustc, disable `download-ci-llvm` in config.toml:

    [llvm]
    download-ci-llvm = false
Build completed unsuccessfully in 0:00:00

[bors]

⌛ Testing commit 9a53cee with merge c5d1b3e...

[bors]

☀️ Test successful - checks-actions
Approved by: compiler-errors
Pushing c5d1b3e to master...

[bors]

☀️ Test successful - checks-actions
Approved by: compiler-errors
Pushing c5d1b3e to master...

[rust-timer]

Finished benchmarking commit (c5d1b3e): comparison URL.

Overall result: ❌✅ regressions and 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)	0.2%	[0.2%, 0.2%]	1
Improvements ✅ (primary)	-0.9%	[-0.9%, -0.9%]	1
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-0.9%	[-0.9%, -0.9%]	1

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)	3.1%	[2.4%, 4.9%]	6
Improvements ✅ (primary)	-4.6%	[-4.6%, -4.6%]	1
Improvements ✅ (secondary)	-2.8%	[-4.6%, -1.0%]	5
All ❌✅ (primary)	-4.6%	[-4.6%, -4.6%]	1

Cycles

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