the unadjusted ABI needs to pass aggregates by-value

[RalfJung]

Fixes #118124, a regression introduced in #117500

[rustbot]

r? @davidtwco

(rustbot has picked a reviewer for you, use r? to override)

[Noratrieb]

Could you just add a test that uses the NEON intrinsic and ensures it doesn't fail to compile?

[RalfJung]

I can probably do a no_core test that works on all hosts...

[bjorn3]

Is the unadjusted ABI marked as internal feature? If not I think we should mark it as such.

[RalfJung]

Not currently:

rust/compiler/rustc_feature/src/unstable.rs

Lines 162 to 163 in efe54e2

	/// Allows using the `unadjusted` ABI; perma-unstable.
	(unstable, abi_unadjusted, "1.16.0", None, None),

But I agree.

[RalfJung]

Could you just add a test that uses the NEON intrinsic and ensures it doesn't fail to compile?

I added a test.

[RalfJung]

@davidtwco or anyone else from @rust-lang/compiler , this fixes a critical codegen regression, would be good to land it ASAP. :)

[compiler-errors]

@bors r+ rollup=never p=1

easier to bisect that way

[bors]

📌 Commit ebfb95a has been approved by compiler-errors

It is now in the queue for this repository.

[bors]

⌛ Testing commit ebfb95a with merge 16087ee...

[bors]

☀️ Test successful - checks-actions
Approved by: compiler-errors
Pushing 16087ee to master...

[rust-timer]

Finished benchmarking commit (16087ee): comparison URL.

Overall result: no relevant changes - no action needed

@rustbot label: -perf-regression

Instruction count

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

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)	4.7%	[4.7%, 4.7%]	1
Regressions ❌ (secondary)	2.6%	[2.6%, 2.6%]	1
Improvements ✅ (primary)	-3.9%	[-3.9%, -3.9%]	1
Improvements ✅ (secondary)	-3.7%	[-4.8%, -2.2%]	4
All ❌✅ (primary)	0.4%	[-3.9%, 4.7%]	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: 675.133s -> 674.958s (-0.03%)
Artifact size: 313.36 MiB -> 313.33 MiB (-0.01%)