Stop using uadd.with.overflow

[scottmcm]

As discussed in #t-compiler/llvm > `uadd.with.overflow` (again) @ 💬, stop emitting uadd.with.overflow in favour of add+icmp instead.

r? nikic

[scottmcm]

@bors try @rust-timer queue

[rust-bors]

⌛ Trying commit 8831c5b with merge d6fe4fe…

To cancel the try build, run the command @bors try cancel.

[rust-bors]

☀️ Try build successful (CI)
Build commit: d6fe4fe (d6fe4fe6836a625695610af12809a3aa52d9647a, parent: 4c7749e8c8e50ad146da599eea3a250160c1bc2b)

[rust-timer]

Finished benchmarking commit (d6fe4fe): comparison URL.

Overall result: ✅ improvements - no action needed

Benchmarking this pull request means it may be perf-sensitive – we'll automatically label it not fit for rolling up. You can override this, but we strongly advise not to, due to possible changes in compiler perf.

@bors rollup=never
@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)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-0.4%	[-0.5%, -0.2%]	5
Improvements ✅ (secondary)	-2.0%	[-2.9%, -0.2%]	9
All ❌✅ (primary)	-0.4%	[-0.5%, -0.2%]	5

Max RSS (memory usage)

Results (primary 4.5%)

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

	mean	range	count
Regressions ❌ (primary)	4.5%	[4.5%, 4.5%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	4.5%	[4.5%, 4.5%]	1

Cycles

Results (secondary -0.7%)

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)	4.5%	[4.5%, 4.5%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-5.8%	[-5.8%, -5.8%]	1
All ❌✅ (primary)	-	-	0

Binary size

Results (primary -0.0%, secondary -0.0%)

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)	-0.0%	[-0.1%, -0.0%]	19
Improvements ✅ (secondary)	-0.0%	[-0.0%, -0.0%]	5
All ❌✅ (primary)	-0.0%	[-0.1%, -0.0%]	19

Bootstrap: 463.02s -> 464.507s (0.32%)
Artifact size: 377.40 MiB -> 377.38 MiB (-0.01%)

[nikic]

@bors r+

[bors]

📌 Commit 8831c5b has been approved by nikic

It is now in the queue for this repository.

[bors]

⌛ Testing commit 8831c5b with merge 7f7b8ef...

[bors]

☀️ Test successful - checks-actions
Approved by: nikic
Pushing 7f7b8ef to master...

[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 8712e45 (parent) -> 7f7b8ef (this PR)

Test differences

Show 20 test diffs

Stage 1

• [assembly] tests/assembly-llvm/x86_64-bigint-helpers.rs: [missing] -> pass (J2)
• [assembly] tests/assembly-llvm/x86_64-bigint-helpers.rs#llvm-20: pass -> [missing] (J2)
• [assembly] tests/assembly-llvm/x86_64-bigint-helpers.rs#llvm-pre-20: ignore (ignored when the LLVM version (20.1.2) is newer than majorversion 19) -> [missing] (J2)
• [assembly] tests/assembly-llvm/x86_64-bigint-helpers.rs: [missing] -> ignore (ignored when the LLVM version 19.1.1 is older than 20.0.0) (J4)
• [assembly] tests/assembly-llvm/x86_64-bigint-helpers.rs#llvm-20: ignore (ignored when the LLVM version 19.1.1 is older than 20.0.0) -> [missing] (J4)
• [assembly] tests/assembly-llvm/x86_64-bigint-helpers.rs#llvm-pre-20: pass -> [missing] (J4)

Stage 2

• [assembly] tests/assembly-llvm/x86_64-bigint-helpers.rs: [missing] -> ignore (ignored when the LLVM version 19.1.1 is older than 20.0.0) (J0)
• [assembly] tests/assembly-llvm/x86_64-bigint-helpers.rs#llvm-20: ignore (ignored when the LLVM version 19.1.1 is older than 20.0.0) -> [missing] (J0)
• [assembly] tests/assembly-llvm/x86_64-bigint-helpers.rs#llvm-pre-20: ignore (ignored when the LLVM version (20.1.2) is newer than majorversion 19) -> [missing] (J1)
• [assembly] tests/assembly-llvm/x86_64-bigint-helpers.rs#llvm-pre-20: ignore (ignored when the LLVM version (21.1.0) is newer than majorversion 19) -> [missing] (J3)
• [assembly] tests/assembly-llvm/x86_64-bigint-helpers.rs: [missing] -> ignore (only executed when the architecture is x86_64) (J5)
• [assembly] tests/assembly-llvm/x86_64-bigint-helpers.rs#llvm-20: ignore (only executed when the architecture is x86_64) -> [missing] (J5)
• [assembly] tests/assembly-llvm/x86_64-bigint-helpers.rs: [missing] -> pass (J6)
• [assembly] tests/assembly-llvm/x86_64-bigint-helpers.rs#llvm-20: pass -> [missing] (J6)
• [assembly] tests/assembly-llvm/x86_64-bigint-helpers.rs#llvm-pre-20: pass -> [missing] (J7)
• [assembly] tests/assembly-llvm/x86_64-bigint-helpers.rs#llvm-pre-20: ignore (only executed when the architecture is x86_64) -> [missing] (J8)

Additionally, 4 doctest diffs were found. These are ignored, as they are noisy.

Job group index

• J0: aarch64-gnu-llvm-19-1, x86_64-gnu-llvm-19-2
• J1: x86_64-gnu-llvm-20-2
• J2: x86_64-gnu-llvm-20-3
• J3: aarch64-apple, aarch64-gnu, aarch64-msvc-1, arm-android, armhf-gnu, dist-i586-gnu-i586-i686-musl, i686-gnu-1, i686-gnu-nopt-1, i686-msvc-1, test-various, x86_64-apple-1, x86_64-gnu, x86_64-gnu-nopt, x86_64-gnu-stable, x86_64-mingw-1, x86_64-msvc-1
• J4: x86_64-gnu-llvm-19-3
• J5: aarch64-apple, aarch64-gnu, aarch64-msvc-1, arm-android, armhf-gnu, dist-i586-gnu-i586-i686-musl, i686-gnu-1, i686-gnu-nopt-1, i686-msvc-1
• J6: test-various, x86_64-apple-1, x86_64-gnu, x86_64-gnu-llvm-20-2, x86_64-gnu-nopt, x86_64-gnu-stable, x86_64-mingw-1, x86_64-msvc-1
• J7: x86_64-gnu-llvm-19-2
• J8: aarch64-gnu-llvm-19-1

Test dashboard

Run

cargo run --manifest-path src/ci/citool/Cargo.toml -- \
    test-dashboard 7f7b8ef27d86c865a7ab20c7c42f50811c6a914d --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. x86_64-apple-1: 8159.0s -> 6329.5s (-22.4%)
2. dist-aarch64-apple: 6400.6s -> 5159.8s (-19.4%)
3. pr-check-2: 2674.4s -> 2195.6s (-17.9%)
4. x86_64-gnu-llvm-19-3: 7455.9s -> 6610.1s (-11.3%)
5. x86_64-rust-for-linux: 2927.7s -> 2613.9s (-10.7%)
6. pr-check-1: 1677.9s -> 1508.3s (-10.1%)
7. aarch64-gnu-llvm-19-2: 2545.2s -> 2302.9s (-9.5%)
8. x86_64-gnu-debug: 6969.9s -> 6356.8s (-8.8%)
9. x86_64-gnu-llvm-20-1: 3542.9s -> 3236.7s (-8.6%)
10. i686-gnu-nopt-1: 7835.4s -> 7168.9s (-8.5%)

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 (7f7b8ef): comparison URL.

Overall result: ❌✅ regressions and improvements - please read the text below

Our benchmarks found a performance regression caused by this PR.
This might be an actual regression, but it can also be just noise.

Next Steps:

• If the regression was expected or you think it can be justified,
  please write a comment with sufficient written justification, and add
  @rustbot label: +perf-regression-triaged to it, to mark the regression as triaged.
• If you think that you know of a way to resolve the regression, try to create
  a new PR with a fix for the regression.
• If you do not understand the regression or you think that it is just noise,
  you can ask the @rust-lang/wg-compiler-performance working group for help (members of this group
  were already notified of this PR).

@rustbot label: +perf-regression
cc @rust-lang/wg-compiler-performance

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)	0.2%	[0.2%, 0.2%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-0.3%	[-0.3%, -0.2%]	7
Improvements ✅ (secondary)	-0.5%	[-0.8%, -0.2%]	14
All ❌✅ (primary)	-0.2%	[-0.3%, 0.2%]	8

Max RSS (memory usage)

Results (primary 2.9%, secondary 2.2%)

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

	mean	range	count
Regressions ❌ (primary)	2.9%	[2.6%, 3.3%]	3
Regressions ❌ (secondary)	2.2%	[2.0%, 2.6%]	3
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	2.9%	[2.6%, 3.3%]	3

Cycles

Results (primary 2.5%)

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

	mean	range	count
Regressions ❌ (primary)	2.5%	[2.5%, 2.5%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	2.5%	[2.5%, 2.5%]	1

Binary size

Results (primary -0.0%, secondary -0.0%)

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)	-0.0%	[-0.1%, -0.0%]	20
Improvements ✅ (secondary)	-0.0%	[-0.0%, -0.0%]	5
All ❌✅ (primary)	-0.0%	[-0.1%, -0.0%]	20

Bootstrap: 462.592s -> 463.378s (0.17%)
Artifact size: 377.39 MiB -> 377.34 MiB (-0.01%)

[nnethercote]

The icount and binary size improvements greatly outweigh the regressions. Wall-time numbers are a bit weird, not sure what to make of them.

@rustbot label: +perf-regression-triaged

[scottmcm]

Wonder if wall time was mostly a glitch; a bunch seem to have come down again in #145210 (comment)