Ban projecting into SIMD types [MCP838]

[scottmcm]

Closes rust-lang/compiler-team#838

The actual compiler change here is tiny; there's just a bazillion tests to update.

Since I'm sure I've missed some, for now
r ghost

try-job: test-various
try-job: x86_64-gnu-nopt

[scottmcm]

Since you previously commented on 138036, how about
r? @compiler-errors

[rustbot]

The Miri subtree was changed

cc @rust-lang/miri

Some changes occurred to MIR optimizations

cc @rust-lang/wg-mir-opt

Some changes occurred in compiler/rustc_codegen_cranelift

cc @bjorn3

Some changes occurred in compiler/rustc_codegen_ssa

cc @WaffleLapkin

[compiler-errors]

@bors r+ rollup

[bors]

📌 Commit fa7734a has been approved by compiler-errors

It is now in the queue for this repository.

[scottmcm]

@bors r-
Needs an update since #144190 merged first

[scottmcm]

And checking the two jobs that have failed in bors without being caught by ci:
@bors try

[bors]

⌛ Trying commit 41ce1ed with merge 4dc4ab1...

[bors]

☀️ Try build successful - checks-actions
Build commit: 4dc4ab1 (4dc4ab197770cfd2da11fb83b224df924e7e594f)

[scottmcm]

Both jobs that have failed in bors on this in the past just succeeded in that last try run, so let's give it another shot 🤞
@bors r=compiler-errors

[bors]

📌 Commit 41ce1ed has been approved by compiler-errors

It is now in the queue for this repository.

[bors]

⌛ Testing commit 41ce1ed with merge e05ab47...

[bors]

☀️ Test successful - checks-actions
Approved by: compiler-errors
Pushing e05ab47 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 460259d (parent) -> e05ab47 (this PR)

Test differences

Show 7 test diffs

Stage 1

• [codegen] tests/codegen/simd/project-to-simd-array-field.rs: pass -> [missing] (J0)
• [ui] tests/ui/mir/validate/project-into-simd.rs: [missing] -> pass (J0)

Stage 2

• [codegen] tests/codegen/simd/project-to-simd-array-field.rs: pass -> [missing] (J1)
• [ui] tests/ui/mir/validate/project-into-simd.rs: [missing] -> pass (J2)

Additionally, 3 doctest diffs were found. These are ignored, as they are noisy.

Job group index

• J0: x86_64-gnu-llvm-19-3, x86_64-gnu-llvm-20-3
• J1: 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-llvm-19-2, x86_64-gnu-llvm-20-2, x86_64-gnu-nopt, x86_64-gnu-stable, x86_64-mingw-1, x86_64-msvc-1
• J2: 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-2, x86_64-gnu, x86_64-gnu-llvm-19-2, x86_64-gnu-llvm-20-2, x86_64-gnu-nopt, x86_64-gnu-stable, x86_64-mingw-1, x86_64-msvc-1

Test dashboard

Run

cargo run --manifest-path src/ci/citool/Cargo.toml -- \
    test-dashboard e05ab47e6c418fb2b9faa2eae9a7e70c65c98eaa --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. dist-apple-various: 7318.3s -> 5588.6s (-23.6%)
2. aarch64-apple: 4203.8s -> 5193.2s (23.5%)
3. x86_64-apple-2: 5373.1s -> 4143.1s (-22.9%)
4. test-various: 4522.2s -> 5035.3s (11.3%)
5. dist-aarch64-apple: 5238.1s -> 5752.6s (9.8%)
6. aarch64-msvc-1: 6968.7s -> 7642.9s (9.7%)
7. dist-ohos-armv7: 3763.3s -> 4089.4s (8.7%)
8. x86_64-msvc-1: 7906.6s -> 8586.6s (8.6%)
9. x86_64-gnu-debug: 6468.4s -> 5934.8s (-8.2%)
10. armhf-gnu: 4885.6s -> 5273.4s (7.9%)

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.

[scottmcm]

I'm glad it worked, but it figures that as soon as I give up on rollups I get it right 🤦

[rust-timer]

Finished benchmarking commit (e05ab47): comparison URL.

Overall result: ❌ regressions - no action needed

@rustbot label: -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)	0.1%	[0.1%, 0.1%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Max RSS (memory usage)

Results (primary -3.2%, secondary -4.1%)

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)	-3.2%	[-5.4%, -1.0%]	2
Improvements ✅ (secondary)	-4.1%	[-6.6%, -2.3%]	6
All ❌✅ (primary)	-3.2%	[-5.4%, -1.0%]	2

Cycles

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

Binary size

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

Bootstrap: 466.025s -> 466.006s (-0.00%)
Artifact size: 374.56 MiB -> 374.60 MiB (0.01%)