Only check inlining counter after recursing.

[cjgillot]

This PR aims to reduce the strength of #105119 even more.

In the current implementation, we check the inline count before recursing. This means that we never actually reach inlining depth 3.

This PR checks the counter after recursion, to give a chance to inline at depth >= 3.

r? @scottmcm
cc @JakobDegen

[rustbot]

Some changes occurred to MIR optimizations

cc @rust-lang/wg-mir-opt

[cjgillot]

@bors try @rust-timer queue

[bors]

⌛ Trying commit 9e68344 with merge 8c6964db79fae5c0e4d65a28b8399e3f128b6909...

[bors]

☀️ Try build successful - checks-actions
Build commit: 8c6964db79fae5c0e4d65a28b8399e3f128b6909 (8c6964db79fae5c0e4d65a28b8399e3f128b6909)

[rust-timer]

Finished benchmarking commit (8c6964db79fae5c0e4d65a28b8399e3f128b6909): 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)	-0.4%	[-0.4%, -0.3%]	2
Improvements ✅ (secondary)	-0.7%	[-1.4%, -0.4%]	8
All ❌✅ (primary)	-0.4%	[-0.4%, -0.3%]	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.

	mean	range	count
Regressions ❌ (primary)	1.9%	[1.6%, 2.2%]	2
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-1.1%	[-1.1%, -1.1%]	1
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.9%	[-1.1%, 2.2%]	3

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)	2.0%	[2.0%, 2.0%]	1
Improvements ✅ (primary)	-3.4%	[-3.8%, -3.1%]	6
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-3.4%	[-3.8%, -3.1%]	6

Binary size

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)	0.1%	[0.0%, 0.4%]	17
Regressions ❌ (secondary)	0.5%	[0.5%, 0.5%]	1
Improvements ✅ (primary)	-0.1%	[-0.2%, -0.0%]	7
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.0%	[-0.2%, 0.4%]	24

Bootstrap: 647.289s -> 646.164s (-0.17%)

[scottmcm]

Looks great! Simple code change, pure win on instructions, helps a known case, and has roughly neutral overall binary size impact (which is probably usually the case for inlining tweaks, and just needs to not be obviously worse on size).

@bors r+

[bors]

📌 Commit 9e68344 has been approved by scottmcm

It is now in the queue for this repository.

[bors]

⌛ Testing commit 9e68344 with merge 9eee230...

[bors]

☀️ Test successful - checks-actions
Approved by: scottmcm
Pushing 9eee230 to master...

[rust-timer]

Finished benchmarking commit (9eee230): 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.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	0.2%	[0.1%, 0.3%]	5
Improvements ✅ (primary)	-0.3%	[-0.5%, -0.2%]	6
Improvements ✅ (secondary)	-0.5%	[-1.0%, -0.3%]	11
All ❌✅ (primary)	-0.3%	[-0.5%, -0.2%]	6

Max RSS (memory usage)

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

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)	-2.8%	[-4.0%, -0.7%]	8
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-2.8%	[-4.0%, -0.7%]	8

Binary size

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)	0.1%	[0.0%, 0.4%]	20
Regressions ❌ (secondary)	0.5%	[0.5%, 0.5%]	1
Improvements ✅ (primary)	-0.2%	[-0.3%, -0.0%]	7
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.0%	[-0.3%, 0.4%]	27

Bootstrap: 647.947s -> 645.202s (-0.42%)

[nnethercote]

Wins outweigh losses.

@rustbot label: +perf-regression-triaged