Optimize Cranelift with PGO

[Kobzol]

Opening for perf. experiments.

[Kobzol]

@bors try jobs=dist-x86_64-linux @rust-timer queue backends=Llvm,Cranelift

[rust-bors]

☀️ Try build successful (CI)
Build commit: 65872f1 (65872f1ea564eab345f03ad14e54001032cffeb0)
Base parent: dba8825 (dba8825fe50879b22129271fb865944e384f7cce)

[rust-timer]

Finished benchmarking commit (65872f1): comparison URL.

Overall result: ❌✅ regressions and improvements - please read:

Benchmarking means the PR may be perf-sensitive. It's automatically marked not fit for rolling up. Overriding is possible but disadvised: it risks changing compiler perf.

Next, please: If you can, justify the regressions found in this try perf run in writing along with @rustbot label: +perf-regression-triaged. If not, fix the regressions and do another perf run. Neutral or positive results will clear the label automatically.

@bors rollup=never rustc-perf
@rustbot label: -S-waiting-on-perf +perf-regression

Instruction count

Our most reliable metric. Used to determine the overall result above. However, even this metric can be noisy.

	mean	range	count
Regressions ❌ (primary)	2.2%	[0.4%, 5.9%]	14
Regressions ❌ (secondary)	1.3%	[0.3%, 4.7%]	102
Improvements ✅ (primary)	-4.1%	[-10.6%, -0.3%]	72
Improvements ✅ (secondary)	-3.2%	[-10.6%, -0.3%]	69
All ❌✅ (primary)	-3.1%	[-10.6%, 5.9%]	86

Max RSS (memory usage)

Results (primary -0.6%, secondary -0.3%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	0.8%	[0.4%, 1.5%]	25
Regressions ❌ (secondary)	1.3%	[0.4%, 4.9%]	84
Improvements ✅ (primary)	-1.0%	[-2.2%, -0.4%]	88
Improvements ✅ (secondary)	-1.3%	[-3.0%, -0.4%]	141
All ❌✅ (primary)	-0.6%	[-2.2%, 1.5%]	113

Cycles

Results (primary -1.2%, secondary -0.1%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	0.9%	[0.4%, 3.3%]	66
Regressions ❌ (secondary)	2.2%	[0.4%, 16.9%]	120
Improvements ✅ (primary)	-2.4%	[-8.7%, -0.4%]	120
Improvements ✅ (secondary)	-2.5%	[-8.5%, -0.4%]	122
All ❌✅ (primary)	-1.2%	[-8.7%, 3.3%]	186

Binary size

This perf run didn't have relevant results for this metric.

Bootstrap: 490.969s -> 492.497s (0.31%)
Artifact size: 408.65 MiB -> 409.36 MiB (0.17%)

[Kobzol]

No changes on LLVM and nice wins for Cranelift. CI duration is extended by maybe 2-3 minutes, only for full builds, so that seems fine.

[rustbot]

This PR modifies bootstrap.example.toml.

If appropriate, please update CONFIG_CHANGE_HISTORY in src/bootstrap/src/utils/change_tracker.rs.

This PR modifies src/bootstrap/src/core/config.

If appropriate, please update CONFIG_CHANGE_HISTORY in src/bootstrap/src/utils/change_tracker.rs.

[rustbot]

r? @Mark-Simulacrum

rustbot has assigned @Mark-Simulacrum.
They will have a look at your PR within the next two weeks and either review your PR or reassign to another reviewer.

Use r? to explicitly pick a reviewer

Why was this reviewer chosen?

The reviewer was selected based on:

• Fallback group: @Mark-Simulacrum, @jieyouxu
• @Mark-Simulacrum, @jieyouxu expanded to Mark-Simulacrum, jieyouxu
• Random selection from Mark-Simulacrum, jieyouxu

[Mark-Simulacrum]

@bors r+

[rust-bors]

📌 Commit 1df9512 has been approved by Mark-Simulacrum

It is now in the queue for this repository.

[rust-bors]

☀️ Test successful - CI
Approved by: Mark-Simulacrum
Duration: 3h 6m 34s
Pushing 56343b1 to main...

[github-actions]

What is this?

This is an experimental post-merge analysis report that shows differences in test outcomes between the merged PR and its parent PR.

Comparing 1d9e680 (parent) -> 56343b1 (this PR)

Test differences

Show 1 test diff

Stage 2

• [run-make] tests/run-make/compressed-debuginfo-zstd: ignore (ignored if LLVM wasn't build with zstd for ELF section compression or LLVM is not the default codegen backend) -> pass (J0)

Job group index

• J0: test-x86_64-gnu-nopt

Test dashboard

Run

cargo run --manifest-path src/ci/citool/Cargo.toml -- \
    test-dashboard 56343b1a7d3fed3f349a5c2dc474f65b504f5221 --output-dir test-dashboard

And then open test-dashboard/index.html in your browser to see an overview of all executed tests.

Job duration changes

1. test-x86_64-mingw-2: 1h 42m -> 2h 46m (+62.2%)
2. dist-sparcv9-solaris: 1h 6m -> 1h 42m (+53.1%)
3. dist-x86_64-msvc: 2h 1m -> 3h 3m (+51.6%)
4. dist-x86_64-apple: 4h 33m -> 2h 14m (-51.0%)
5. dist-powerpc64le-linux-gnu: 1h 9m -> 1h 40m (+44.5%)
6. test-x86_64-gnu-gcc: 1h 36m -> 54m 54s (-43.0%)
7. dist-x86_64-freebsd: 1h 3m -> 1h 29m (+41.7%)
8. test-x86_64-msvc-ext3: 1h 57m -> 1h 8m (-41.1%)
9. test-x86_64-gnu-nopt: 1h 49m -> 2h 34m (+40.3%)
10. test-x86_64-msvc-2: 1h 52m -> 2h 35m (+39.0%)

How to interpret the job duration changes?

Job durations can vary a lot, based on the actual runner instance
that executed the job, system noise, invalidated caches, etc. The table above is provided
mostly for t-infra members, for simpler debugging of potential CI slow-downs.

[rust-timer]

Finished benchmarking commit (56343b1): comparison URL.

Overall result: no relevant changes - no action needed

@rustbot label: -perf-regression

Instruction count

This perf run didn't have relevant results for this metric.

Max RSS (memory usage)

Results (primary -3.6%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-3.6%	[-3.6%, -3.6%]	1
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-3.6%	[-3.6%, -3.6%]	1

Cycles

Results (primary 5.2%, secondary 2.7%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	5.2%	[5.2%, 5.2%]	1
Regressions ❌ (secondary)	2.7%	[2.3%, 3.2%]	2
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	5.2%	[5.2%, 5.2%]	1

Binary size

This perf run didn't have relevant results for this metric.

Bootstrap: 488.976s -> 488.752s (-0.05%)
Artifact size: 408.69 MiB -> 408.67 MiB (-0.00%)